liu.seSök publikationer i DiVA
Ändra sökning
Avgränsa sökresultatet
1234567 151 - 200 av 365
RefereraExporteraLänk till träfflistan
Permanent länk
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • oxford
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Träffar per sida
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sortering
  • Standard (Relevans)
  • Författare A-Ö
  • Författare Ö-A
  • Titel A-Ö
  • Titel Ö-A
  • Publikationstyp A-Ö
  • Publikationstyp Ö-A
  • Äldst först
  • Nyast först
  • Skapad (Äldst först)
  • Skapad (Nyast först)
  • Senast uppdaterad (Äldst först)
  • Senast uppdaterad (Nyast först)
  • Disputationsdatum (tidigaste först)
  • Disputationsdatum (senaste först)
  • Standard (Relevans)
  • Författare A-Ö
  • Författare Ö-A
  • Titel A-Ö
  • Titel Ö-A
  • Publikationstyp A-Ö
  • Publikationstyp Ö-A
  • Äldst först
  • Nyast först
  • Skapad (Äldst först)
  • Skapad (Nyast först)
  • Senast uppdaterad (Äldst först)
  • Senast uppdaterad (Nyast först)
  • Disputationsdatum (tidigaste först)
  • Disputationsdatum (senaste först)
Markera
Maxantalet träffar du kan exportera från sökgränssnittet är 250. Vid större uttag använd dig av utsökningar.
  • 151. Beställ onlineKöp publikationen >>
    Kowalkowski, Christian
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Industriell marknadsföring och industriell ekonomi. Linköpings universitet, Tekniska högskolan.
    Enhancing the Industrial Service Offering: New Requirements on Content and Processes2006Licentiatavhandling, monografi (Övrigt vetenskapligt)
    Abstract [en]

    The overall purpose of this thesis is to describe and analyse how capital goods manufacturers can enhance their industrial service offering.

    The theoretical basis of this research is found in services marketing, recognising co-creation of value, that the service process is an open production system and that the customer determines value as the manufacturer can only offer value propositions.

    The empirical basis is a multiple case study of service management at BT Industries, Electrolux Laundry Systems, ITT Flygt, and Saab. The four companies operate within different industries, have different service offerings and they are facing different internal and external conditions, which affect their service organisation and offering.

    It is becoming increasingly important for capital goods manufacturers to offer services and there are further growth and profit opportunities on the market for industrial services. It is suggested that there is major improvement potential and financial gains possible to achieve if more resources are allocated to services. Moreover, utilisation of new technological means leads to increased dematerialisation and enable manufacturers to enhance existing service offerings as well as enable new ones.

    Depending on whether the services have a traditional product-orientated focus or a customer-centric process-orientated focus, and depending on the scope of the offering, there are different critical factors to consider. Process-orientated services require knowledge about not only how to service the installed base but also how to improve the customer’s industrial production process.

    Generally, bundled services require a modular structure with standardised, formalised processes and integration between local and central organisation. Extensive bundled offerings require that both customer and provider have relational intent and a long-term relationship is regarded as a condition for successful customer involvement in service development. Long-term relationships also enable the company to act proactive and develop offerings with a customer-centric approach, instead of having a product-centric approach and internally-focused innovation.

    To conclude, operational service processes and interfaces, internal and with the customer, are critical to manage both from a cost-efficiency and revenue-effectiveness perspective. Furthermore, it is argued that customer relationships and development of the service offering must be managed strategically.

    Ladda ner fulltext (pdf)
    FULLTEXT01
  • 152. Beställ onlineKöp publikationen >>
    Kowalkowski, Christian
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Industriell marknadsföring och industriell ekonomi. Linköpings universitet, Tekniska högskolan.
    Managing the Industrial Service Function2008Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    During the past decade, growing attention has been given to industrial service offerings in the marketing literature as well as in many manufacturing firms. This phenomenon is often described as a goods-services transition, in which companies increasingly turn to the provision of industrial services in order to achieve competitive advantage, such a closer customer relationships and higher profit margins. Industrial services span a wide range of offerings, from basic after-sales services to process-orientated solutions consisting of both services and capital goods. With industrial service offerings receiving increased attention as their importance is understood, the ability to manage the service business in a manufacturing context becomes ever more vital.

    The overall purpose of this doctoral thesis is to describe and analyse how capital equipment manufacturing firms strategically manage their industrial service offerings in order to achieve long-term competitive advantage. This includes analysing how to organise the firm for the development and production of service, and, depending on the type of industrial service offering, what the requirements on the service processes are. Furthermore the role of information and communication technologies as enablers for new offerings and processes is analysed. The thesis consists of a compilation of five papers, two case descriptions and an extended summary. The research builds on a multiple case study of the service organisations of market-leading manufacturing firms. The main cases are based on in-depth studies at ITT Water & Wastewater and Toyota Material Handling Group.

    The results suggest that, as the division between goods and services becomes ever more blurred, there is an increasing need for cooperation between the service and the product organisations. Applying a service logic means that the traditional division between goods sales and after-sales services becomes outdated. Instead, the customer relationship becomes the centre of the offering regardless of its combination of services and goods. Further, the infusion of service in manufacturing firms means that more service processes and interfaces have to be managed simultaneously.

    Theoretically, this research contributes mainly to the fields of industrial marketing and service as a business logic. One contribution is the proposed typologies for industrial service offerings which make it possible to better understand the dynamics of service processes. Another important contribution of this research is the service function concept. Industrial services must not be equated with the activities of the industrial service organisation only. Although the service organisation most likely is the key entity, it is only one subset of the service function; sales product development, manufacturing, senior management, and other organisational entities, as well as external service providers and customers, are to be seen as part-time service functions that influence the offering. Compared to previously, competitive advantage through industrial service offerings is to a greater extent based on factors outside the service organisation, i.e. in other parts of the service function.

    Delarbeten
    1. Service productivity gains through information and communication technology applications: A service marketing approach
    Öppna denna publikation i ny flik eller fönster >>Service productivity gains through information and communication technology applications: A service marketing approach
    2008 (Engelska)Ingår i: International Journal of Knowledge Management Studies, ISSN 1743-8268, E-ISSN 1743-8276, Vol. 2, nr 1, s. 96-114Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    Based on examples from Information and Communication Technology- (ICT-) based improvements in service productivity in the service organisations of three manufacturing firms, this paper argues for a service-centred approach towards productivity. When improving the productivity of industrial services, one of the three profitability-generating strategies, cost-efficiency, revenue effectiveness and capacity utilisation – or a combination – can be used. Increased standardisation and automation is a consequence of technological development, making capacity less a constraint in services and even if ICT applications often primarily improve cost efficiency, the elements improved vary depending on the solution implemented. Thus, ICT can enhance existing service processes and enable new service offerings to increase overall profitability. A productivity model for ICT-based services is presented and it is suggested that central coordination is often required in order to develop ICT-based services.

    Nyckelord
    service productivity, information and communication technology, ICT, service offerings, cost efficiency, revenue effectiveness, capacity utilisation, front office, back office
    Nationell ämneskategori
    Produktionsteknik, arbetsvetenskap och ergonomi
    Identifikatorer
    urn:nbn:se:liu:diva-12458 (URN)10.1504/IJKMS.2008.016440 (DOI)
    Anmärkning
    Original Publication: Christian Kowalkowski, Service productivity gains through information and communication technology applications: A service marketing approach, 2008, International Journal of Knowledge Management Studies, (2), 1, 96-114. http://dx.doi.org/10.1504/IJKMS.2008.016440 Copyright: Inderscience Publishers http://www.inderscience.com/index.php Tillgänglig från: 2008-09-05 Skapad: 2008-09-05 Senast uppdaterad: 2017-12-14Bibliografiskt granskad
    2. Technology as a driver for changing customer-provider interfaces
    Öppna denna publikation i ny flik eller fönster >>Technology as a driver for changing customer-provider interfaces
    2008 (Engelska)Ingår i: Management research news, ISSN 0140-9174, Vol. 31, nr 10, s. 746-757Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    The purpose of this paper is to explore how information and communication technology (ICT) is affecting and driving changes in the service processes and customer interfaces of capital goods manufacturers.  

    Nyckelord
    Communication technologies, service industries, customer relations
    Nationell ämneskategori
    Teknik och teknologier
    Identifikatorer
    urn:nbn:se:liu:diva-43118 (URN)10.1108/01409170810908507 (DOI)71864 (Lokalt ID)71864 (Arkivnummer)71864 (OAI)
    Anmärkning
    Original Publication: Christian Kowalkowski and Per-Olof Brehmer, Technology as a driver for changing customer-provider interfaces, 2008, Management research news, (31), 10, 746-757. http://dx.doi.org/10.1108/01409170810908507 Copyright: Emerald Group Publishing Limited http://www.emeraldinsight.com/ Tillgänglig från: 2009-10-10 Skapad: 2009-10-10 Senast uppdaterad: 2014-04-14
    3. Managing industrial service offerings: requirements on content and processes
    Öppna denna publikation i ny flik eller fönster >>Managing industrial service offerings: requirements on content and processes
    2009 (Engelska)Ingår i: International Journal of Services Technology and Management, ISSN 1460-6720, E-ISSN 1741-525X, Vol. 11, nr 1, s. 42-63Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    This paper develops a typology for industrial service offerings, inter-relating service scope (degree of bundling), service focus (level of customer integration), and service process interfaces. Different forms of industrial services and the impact of information and communication technology on the three service dimensions are discussed, and requirements are identified related to the expansion of services. It is suggested that bundled and process-orientated services hold a major potential for manufacturing companies and can facilitate the creation of competitive advantage and long-term relationships with customers. Increased knowledge of the customers’ installed base and business processes enables better customisation of the service offerings. Even if more emphasis is put on standardising and formalising central and local processes, companies need to recognise local differences among subsidiaries.

    Nyckelord
    Industrial service offerings, manufacturing companies, service scope, service focus, service process interfaces, bundling, customer integration, services management
    Nationell ämneskategori
    Teknik och teknologier
    Identifikatorer
    urn:nbn:se:liu:diva-12460 (URN)10.1504/IJSTM.2009.022381 (DOI)
    Anmärkning
    Original Publication: Christian Kowalkowski, Per-Olof Brehmer and Daniel Kindström, Managing industrial service offerings: requirements on content and processes, 2009, International Journal of Services Technology and Management, (11), 1, 42-63. http://dx.doi.org/10.1504/IJSTM.2009.022381 Copyright: Inderscience Enterprises Ltd http://www.inderscience.com/ Tillgänglig från: 2008-09-05 Skapad: 2008-09-05 Senast uppdaterad: 2017-12-14
    4. Managing industrial service offerings in global business markets
    Öppna denna publikation i ny flik eller fönster >>Managing industrial service offerings in global business markets
    2011 (Engelska)Ingår i: Journal of business & industrial marketing, ISSN 0885-8624, E-ISSN 2052-1189, Vol. 26, nr 3, s. 181-192Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    Purpose – Despite the increased focus on industrial services in manufacturing companies, little research to date has focused on understanding the roles of local and central organizations in global service management. In order to address this research gap, the paper investigates how industrial service offerings are developed and managed in multinational manufacturing companies.

    Design/methodology/approach – A qualitative case study with respondents from two internationally leading manufacturers was conducted. Eight industrial service offerings with different characteristics serve as units of analysis.

    Findings – A broad portfolio of industrial service offerings implies having a very wide range of skill sets, including both global efficiency and local responsiveness. With specialized and extensive offerings, it becomes more important to have a high level of central-local and product-service integration and to internalize service provision. Furthermore, with global customers, the central service organization needs to assume a more prominent role, initiating both an organizational exploitation of current service capabilities and the exploration of new ones.

    Research limitations/implications – The main focus was on service offerings performed by high-volume manufacturing companies operating primarily in developed markets.

    Originality/value – Previous studies of industrial service management in manufacturing companies have not explicitly considered the roles of central and local organizations. Thus, the authors were able to complement the existing theory. The paper promotes a deeper understanding of the complexity of managing service offerings on a global basis.

    Nyckelord
    Industrial service offerings, Multinational companies, International business, Service systems
    Nationell ämneskategori
    Företagsekonomi
    Identifikatorer
    urn:nbn:se:liu:diva-12461 (URN)10.1108/08858621111115903 (DOI)000290647000005 ()
    Anmärkning

    Original Publication: Christian Kowalkowski, Daniel Kindström and Per-Olof Brehmer, Managing industrial service offerings in global business markets, 2011, Journal of Business & Industrial Marketing, (26), 3, 181-192. http://dx.doi.org/10.1108/08858621111115903 Copyright: Emerald Group Publishing Limited http://www.emeraldinsight.com/

    Tillgänglig från: 2008-09-05 Skapad: 2008-09-05 Senast uppdaterad: 2020-06-09
    5. How World Leading Manufacturers Can Achieve Differentiation Through E-Business: New Services, Enhanced Relationships, and Reduced Costs
    Öppna denna publikation i ny flik eller fönster >>How World Leading Manufacturers Can Achieve Differentiation Through E-Business: New Services, Enhanced Relationships, and Reduced Costs
    2007 (Engelska)Ingår i: 18th Information Resources Management Association International Conference, Vancouver, Canada: Managing Worldwide Operations and Communications with Information Technology, Hershey, New York: IGI Global , 2007, s. 502-506Konferensbidrag, Publicerat paper (Refereegranskat)
    Abstract [en]

    E-business development is today driven by mature and established companies and is becoming an important tool to increase competitive advantage and to sustain profitability. This paper investigates how world-leading manufacturers can achieve differentiation through their use of e-business. Many companies use e-business as vehicles to launch new information-based service, as an important enabler to enhance and deepen customer relationships, and to reduce costs associated with customer management. Using e-business in this way will increase the opportunities for differentiation and create sustainable competitive advantage. Successful employment of e-business creates services that retain current customers and attract new ones as well as justifies premium prices and keeps low-cost competitors in check.

    Ort, förlag, år, upplaga, sidor
    Hershey, New York: IGI Global, 2007
    Nyckelord
    E-business, Differentiation, Value creation, Offerings, Services
    Nationell ämneskategori
    Produktionsteknik, arbetsvetenskap och ergonomi
    Identifikatorer
    urn:nbn:se:liu:diva-12462 (URN)978-1-59904-929-8 (ISBN)
    Tillgänglig från: 2008-09-05 Skapad: 2008-09-05 Senast uppdaterad: 2014-04-14Bibliografiskt granskad
    Ladda ner fulltext (pdf)
    FULLTEXT01
    Ladda ner (pdf)
    COVER01
  • 153.
    Kristensson, Malte
    et al.
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluida och mekatroniska system.
    Hassel, Jesper
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluida och mekatroniska system.
    Development of a Power Hardware-in-the-Loop Test Rig for Gas Hydraulic Suspension in Heavy Duty Vehicles2022Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    In this thesis a Power-Hardware-in-the-Loop (PHiL) test rig is developed forhydro-pneumatic suspension by utilizing the physical suspension unit together with asimulated vehicle model in MATLAB Simulink. Power-Hardware-in-the-Loop is the termfor combining simulation models with power-transmitting hardware components inreal-time. This is useful when a system contains some parts that are complex and somethat are simpler to model. The simple parts of the system can be modelled andsimulated in conjunction with more complex parts consisting of physical objects. Thereason for keeping the items to be tested as physical components is their complexity andunknown characteristics that can be difficult to estimate. By utilizing PHiL, vehiclecomponents can be tested and developed without the need for the actual vehicle, whilekeeping the characteristics that the physical vehicle would bring.

    The process included development of a real-time enabled vehicle model, evaluation ofcontrol strategies as well as selection of hardware used for a small scale test rig.

    The project resulted in a functional small scale single wheel test rig. Validationexperiments confirmed that the rig produced results close to expectations. Thecommunication between the the test rig and the simulated model was accurate andshowed the potential for a full scale test rig. It can be concluded that a PHiL test rigcan be a suitable option to full vehicle testing. The vehicle model is fully customisable,so that the suspension units can be tested in various configurations of vehicles.

    Ladda ner fulltext (pdf)
    fulltext
  • 154.
    Krus, Petter
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluida och mekatroniska system. Linköpings universitet, Tekniska fakulteten.
    Design Space Configuration Through Analytical Parametrization2017Ingår i: Research into Design for Communities, Volume 1: Proceedings of ICoRD 2017 / [ed] Amaresh Chakrabarti, Debkumar Chakrabarti, Singapore: Springer , 2017, 1, s. 15-24Kapitel i bok, del av antologi (Refereegranskat)
  • 155.
    Krus, Petter
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluida och mekatroniska system. Linköpings universitet, Tekniska högskolan.
    Robust Modelling Using Bi-Lateral Delay Lines for High Speed Simulation of Complex Systems2011Ingår i: DINAME 2011: 14th International Symposium on Dynamic Problems in Mechanics / [ed] Agenor Toledo Fleury, 2011Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    A very effective method for modelling and simulation of large complex dynamic systems is represented by distributed modelling using transmission line elements (or bi-lateral delay lines). This method evolves naturally for calculation of pressures when hydraulic pipelines are modelled with distributed parameters, and it can be used to effectively partition the model to use local solvers for the differential equations in each component or subsystem. It is also applicable to other physical systems, such as mechanical, electrical, gas etc.

    One interesting application for distributed solvers using bi-lateral delay lines is in real time simulation, since they are very robust and usually quite large simulation times steps can be used. Modelling for real-time applications puts special requirements on robustness in the numerical methods used. In real-time applications there is no room for decreasing time step in numerically critical stages. Furthermore, if a system is relaying on a real-time simulation for its functionality, failure in the numerical properties is unacceptable. It is also in many applications possible to simulate the system faster than real time, which means that high fidelity system simulation can be used to plan ahead in control applications, and for simulation based optimisation.

    Since solvers can be embedded in components or subsystems, it is very straightforward to implement parallel processing using the multi-core processors which now is the standard for desk top computers. There is also an increasing need in many situations to resolve the time scale to finer details, where the effect of wave propagation needs to be modelled.

    Ladda ner fulltext (pdf)
    Robust Modelling Using Bi-Lateral Delay Lines for High Speed Simulation of Complex Systems
  • 156.
    Krus, Petter
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluida och mekatroniska system. Linköpings universitet, Tekniska fakulteten.
    Transmission line modelling for system simulation2021Rapport (Övrigt vetenskapligt)
    Abstract [en]

    This text is about system simulation using transmission line method, TLM, to obtain partitioned models that can be used with local solvers, and can be used for parallel processing. Relaying on local solvers also means that good scaling properties are obtained. This is exemplified with the modelling of diffrerent components for e.g. as electronic, hydraulic and mechanical systems.

    Ladda ner fulltext (pdf)
    TransmissionLineModelling
    Ladda ner (png)
    presentationsbild
  • 157.
    Krus, Petter
    et al.
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluida och mekatroniska system. Linköpings universitet, Tekniska högskolan.
    Ölvander, Johan
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Maskinkonstruktion. Linköpings universitet, Tekniska högskolan.
    Performance index and meta-optimization of a direct search optimization method2013Ingår i: Engineering optimization (Print), ISSN 0305-215X, E-ISSN 1029-0273, Vol. 45, nr 10, s. 1167-1185Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Design optimization is becoming an increasingly important tool for design, often using simulation as part of the evaluation of the objective function. A measure of the efficiency of an optimization algorithm is of great importance when comparing methods. The main contribution of this article is the introduction of a singular performance criterion, the entropy rate index based on Shannon's information theory, taking both reliability and rate of convergence into account. It can also be used to characterize the difficulty of different optimization problems. Such a performance criterion can also be used for optimization of the optimization algorithms itself. In this article the Complex-RF optimization method is described and its performance evaluated and optimized using the established performance criterion. Finally, in order to be able to predict the resources needed for optimization an objective function temperament factor is defined that indicates the degree of difficulty of the objective function.

    Ladda ner fulltext (pdf)
    fulltext
  • 158.
    Kvålshaugen, Ragnhild
    et al.
    BI Norwegian Business School Oslo, Norway .
    Hylde, Katja Maria
    International Research Institute of Stavanger Oslo, Norway .
    Brehmer, Per-Olof
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Industriell ekonomi. Linköpings universitet, Tekniska fakulteten.
    Innovative capabilities in international professional service firms: enabling trade-offs between past, present, and future service provision2015Ingår i: Journal of Professions and Organization, ISSN 2051-8803, E-ISSN 2051-8811, Vol. 2, nr 2, s. 148-167Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This study examines the relationship between service provision and innovation in international professional service firms (IPSFs). Through an extended study in one IPSF, we find that innovation stems from the provision of services in the past and present. Different service provisions offer different learning opportunities which influence the modification, renewal, and creation of service concepts, service processes, technologies, and relationships. In order to take advantage of the learning opportunities, certain operational and dynamics capabilities are identified as important. With regard to operational capabilities, understanding customer needs, internal learning, formalization, external and relational learning, integration, and commercialization are identified as important capabilities. Further, two dynamic capabilities driving innovation are identified: learning and knowledge accumulation and scaling and expanding the service portfolio. The learning and knowledge accumulation capability is grounded in the efficient provision of standardized-provided services. By providing these services, insights into customer’s needs are gained, specialized expertise is developed, and reputation and legitimacy for solving novel and complex problems increase. The scaling and expanding capability enables the IPSF to develop customized–co-produced services into standardized-provided services over time with global outreach. Our study shows that careful management of the service portfolio is of utmost strategic importance for the sustainable competitive advantage of IPSFs.

  • 159. Beställ onlineKöp publikationen >>
    Kärnell, Samuel
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluida och mekatroniska system. Linköpings universitet, Tekniska fakulteten.
    On Electrified Fluid Power Systems in Mobile Machinery2022Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    High power density in combination with flexible power distribution possibilities and extreme robustness are reasons why fluid power has been the preferred technology in mobile machinery, such as excavators and cranes, since the mid-20th century. In principle, the machines have been powered by a combustion engine which powers a pump, with the output from the pump being distributed to different functions via valves. However, a transformation is currently underway. Combustion engines are being replaced by electric motors, and batteries able to store energy corresponding to several hours of operation are often desired. Since batteries tend to be heavy and expensive, reducing the energy consumption is getting higher priority than ever before. There are applications where electrification means that hydraulic components are replaced by electric counterparts, but fluid power has characteristics that are highly desirable in mobile machinery. Therefore, many hydraulic actuators will remain. Conventional hydraulic systems, which are known for their inefficiency, should, however, be adapted to the new conditions brought about by electrification. The question, and the overall subject of this thesis, is: how? The research has focused on two main topics: pump-controlled systems, which are systems where each actuator has its own supply unit, and the use of variable displacement pumps in electrified systems.

    A large proportion of the losses in many conventional hydraulic systems is due to the simultaneous operation of functions that require different pressure levels. One way to avoid these losses is to use pump-controlled systems. How these systems should be designed is, however, far from obvious. In this thesis, different types of pump-controlled systems are compared, both statically and dynamically.

    Regarding variable displacement pumps, they have had a natural place in many conventional systems, but electrification may change this, since speed-control can now also be used for flow- and pressure control. However, there are still aspects relating to energy consumption and component dimensioning, among other things, that makes variable pumps relevant. These aspects are investigated here, and different types of variable pumps are reviewed.

    Delarbeten
    1. Classification and Review of Variable Displacement Fluid Power Pumps and Motors
    Öppna denna publikation i ny flik eller fönster >>Classification and Review of Variable Displacement Fluid Power Pumps and Motors
    2023 (Engelska)Ingår i: International Journal of Fluid Power, ISSN 1439-9776, Vol. 24, nr 2, s. 207-246Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    Displacement control of positive displacement machines has been a part of fluid power since the early days. Some of the early hydraulic presses already used two different displacement settings, though this was realised by using two different pumps rather than changing the displacement. Later, radial motors with variable stroke length appeared, followed by other designs of variable machines, such as swashplate machines, bent-axis machines, and variable vane machines. All these solutions control the displacement by varying the volume difference of the displacement element – but there are other ways of achieving this. Most have not passed the research state, but some are commercially available. In this paper, different ways of varying the displacement are presented and classified. The classification divides concepts into either control of displaced fluid or control of usage of displaced fluid. In turn, these concepts can be either on system level or displacement element level. This results in four main classes, which to some extent can describe the characteristics of the control.

    Ort, förlag, år, upplaga, sidor
    River Publishers, 2023
    Nyckelord
    variable displacement, hydraulic pumps, positive displacement machines, review
    Nationell ämneskategori
    Maskinteknik
    Identifikatorer
    urn:nbn:se:liu:diva-193538 (URN)10.13052/ijfp1439-9776.2423 (DOI)000992827500004 ()
    Anmärkning

    Funding: Swedish Energy Agency [44427-3]

    Tillgänglig från: 2023-05-04 Skapad: 2023-05-04 Senast uppdaterad: 2023-06-15Bibliografiskt granskad
    2. Digital pumps in speed-controlled systems: an energy study for a loader crane application
    Öppna denna publikation i ny flik eller fönster >>Digital pumps in speed-controlled systems: an energy study for a loader crane application
    2020 (Engelska)Konferensbidrag, Publicerat paper (Refereegranskat)
    Abstract [en]

    Imagine a system with a pump driven by a speed-controlled electric motor. What and how much can be gained by using a pump with discretely variable displacement instead of a conventional fixed pump in such a system? This question is the focus in this paper, in which a simulation study based on a drive cycle for a loader crane is presented. The results indicate that the system efficiency from inverter input to pump output can increase by a few percentages. This might be considered small in relation to the increasing complexity that comes with discrete displacement. However, the results also show that a system with discrete displacement substantially reduces torque and cooling requirements on the electric motor. The required maximum torque can be reduced by 30 to 50 % and the motor can generate up to 40 % less heat since it can work in more efficient conditions. These potential benefits will be obtained with only a few discrete displacement settings available.

    Ort, förlag, år, upplaga, sidor
    Dresden: , 2020
    Nyckelord
    Digital pumps, Loader crane, Speed-controlled system
    Nationell ämneskategori
    Maskinteknik
    Identifikatorer
    urn:nbn:se:liu:diva-169404 (URN)10.25368/2020.71 (DOI)
    Konferens
    12th International Fluid Power Conference (12. IFK). Dresden, October 12 – 14, 2020
    Projekt
    STEALTH - Sustainable Electrified Load Handling
    Forskningsfinansiär
    Energimyndigheten, 44427-1
    Tillgänglig från: 2020-09-14 Skapad: 2020-09-14 Senast uppdaterad: 2022-08-19Bibliografiskt granskad
    3. Analysis of a Digital Pump With Variable Speed Drive
    Öppna denna publikation i ny flik eller fönster >>Analysis of a Digital Pump With Variable Speed Drive
    2022 (Engelska)Konferensbidrag, Publicerat paper (Refereegranskat)
    Abstract [en]

    The interest in speed-control of hydraulic pumps is increasing with the electrification of mobile machinery. With speed-control at hand, it is tempting to use fixed pumps where variable pumps earlier have been used. However, it can be beneficial to use variable pumps in combination with variable speed since it can allow downsizing of electric machines and reduce losses. But there are downsides with conventional variable pumps, such as increased complexity, cost, and low efficiency. Digital pumps (i.e., pumps with a discrete number of displacement settings) can address these problems. This paper is focused on the performance of a digital pump, both efficiency-wise and from a dynamic perspective. Shunt-based concepts that can improve the dynamics during switching are proposed. Simulation results show that the concepts can reduce the disruption in output flow during switchings.

    Nationell ämneskategori
    Annan maskinteknik
    Identifikatorer
    urn:nbn:se:liu:diva-189982 (URN)10.1115/FPMC2022-88503 (DOI)978-0-7918-8633-5 (ISBN)
    Konferens
    BATH/ASME 2022 Symposium on Fluid Power and Motion Control
    Forskningsfinansiär
    Energimyndigheten, 44427-3
    Tillgänglig från: 2022-11-14 Skapad: 2022-11-14 Senast uppdaterad: 2022-11-15
    4. Pump-Controlled Actuators with Dump Valves
    Öppna denna publikation i ny flik eller fönster >>Pump-Controlled Actuators with Dump Valves
    2021 (Engelska)Ingår i: Proceedings of the 17:th Scandinavian International Conference on Fluid Power, Linköping, 2021Konferensbidrag, Publicerat paper (Refereegranskat)
    Ort, förlag, år, upplaga, sidor
    Linköping: , 2021
    Serie
    Linköping Electronic Conference Proceedings, ISSN 1650-3686, E-ISSN 1650-3740 ; 182
    Nationell ämneskategori
    Maskinteknik
    Identifikatorer
    urn:nbn:se:liu:diva-181230 (URN)10.3384/ecp182 (DOI)978-91-7929-013-9 (ISBN)
    Konferens
    The 17th Scandinavian International Conference on Fluid Power, SICFP’21
    Forskningsfinansiär
    Energimyndigheten, 44427-3
    Tillgänglig från: 2021-11-23 Skapad: 2021-11-23 Senast uppdaterad: 2022-08-19
    5. Hysteresis Control in Pump-Controlled Systems: A Way to Reduce Mode-Switch Oscillations in Closed and Open Circuits
    Öppna denna publikation i ny flik eller fönster >>Hysteresis Control in Pump-Controlled Systems: A Way to Reduce Mode-Switch Oscillations in Closed and Open Circuits
    2022 (Engelska)Ingår i: Energies, E-ISSN 1996-1073, Vol. 15, nr 2, artikel-id 424Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    There is growing interest in using electric motors as prime movers in mobile hydraulic systems. This increases the interest in so-called pump-controlled systems, where each actuator has its own drive unit. Such architectures are primarily appealing in applications where energy efficiency is important and electric recuperation is relevant. An issue with pump-controlled systems is, however, mode-switch oscillations which can appear when the pressure levels in the system are close to the switching condition. In this paper, the mode-switching behavior of different generalized closed and open circuit configurations is investigated. The results show that the choice of where to sense the pressures has a huge impact on the behavior. They also show that, if the pressure sensing components are properly placed, closed and open circuits can perform very similarly, but that mode-switch oscillations still can occur in all circuits. Active hysteresis control is suggested as a solution and its effectiveness is analyzed. The outcome from the analysis shows that active hysteresis control can reduce the risk for mode-switch oscillations significantly.

    Ort, förlag, år, upplaga, sidor
    MDPI, 2022
    Nyckelord
    pump-controlled systems; mode-switch oscillations; hysteresis control
    Nationell ämneskategori
    Maskinteknik
    Identifikatorer
    urn:nbn:se:liu:diva-182259 (URN)10.3390/en15020424 (DOI)000747489000001 ()
    Forskningsfinansiär
    Energimyndigheten, 44427-3
    Anmärkning

    Funding: Swedish Energy AgencySwedish Energy AgencyMaterials & Energy Research Center (MERC) [44427-3]

    Tillgänglig från: 2022-01-11 Skapad: 2022-01-11 Senast uppdaterad: 2023-08-28
    Ladda ner fulltext (pdf)
    fulltext
    Ladda ner (png)
    presentationsbild
  • 160.
    Kärnell, Samuel
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluida och mekatroniska system. Linköpings universitet, Tekniska fakulteten.
    The History and Future of Fluid Power Pumps and Motors2022Ingår i: Proceedings of the 6th Workshop on Innovative Engineering for Fluid Power (WIEFP 2022), 2022, s. 51-56Konferensbidrag (Refereegranskat)
    Abstract [en]

    Positive displacement pumps have been around for thousands of years, but it was first in the beginning of the 19th century they started to be used for power transmission purposes. At that time, the fluid was water, and the applications were primarily presses. During the century, the technology developed and towards its end, fluid power systems were used to transmit power to hundreds or even thousands of consumers within several cities. However, in the 20th century, these large-scale fluid power transmission systems were outcompeted by the electric grid. But at the same time, the focus for fluid power was shifted towards self-contained, oil-based systems, which were suitable in many mobile applications powered by combustion engines. Once again, fluid power systems are now undergoing a transition. This especially apply to mobile applications, where combustion engines are being replaced by electric motors. This puts new requirements on the hydraulic systems as well as the pumps and motors that are to be used. Electrification means increased focus on energy efficiency, and speed-control becomes more relevant than before. New system designs are therefore highly relevant. Depending on the architecture that is chosen, different requirements will be set on the pumps and motors. Aspects such as multi-mode operation, high- and low-speed performance, and displacement control will be discussed in this paper.

  • 161.
    Kärnell, Samuel
    et al.
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluida och mekatroniska system. Linköpings universitet, Tekniska fakulteten.
    Ericson, Liselott
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluida och mekatroniska system. Linköpings universitet, Tekniska fakulteten.
    Analysis of a Digital Pump With Variable Speed Drive2022Konferensbidrag (Refereegranskat)
    Abstract [en]

    The interest in speed-control of hydraulic pumps is increasing with the electrification of mobile machinery. With speed-control at hand, it is tempting to use fixed pumps where variable pumps earlier have been used. However, it can be beneficial to use variable pumps in combination with variable speed since it can allow downsizing of electric machines and reduce losses. But there are downsides with conventional variable pumps, such as increased complexity, cost, and low efficiency. Digital pumps (i.e., pumps with a discrete number of displacement settings) can address these problems. This paper is focused on the performance of a digital pump, both efficiency-wise and from a dynamic perspective. Shunt-based concepts that can improve the dynamics during switching are proposed. Simulation results show that the concepts can reduce the disruption in output flow during switchings.

  • 162.
    Kärnell, Samuel
    et al.
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluida och mekatroniska system. Linköpings universitet, Tekniska fakulteten.
    Ericson, Liselott
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluida och mekatroniska system. Linköpings universitet, Tekniska fakulteten.
    Control of an Asymmetric Cylinder With Two Individually Controlled Pump/Motors2023Ingår i: Proceedings of the ASME/BATH 2023Symposium on Fluid Power and Motion Control, AMER SOC MECHANICAL ENGINEERS , 2023Konferensbidrag (Refereegranskat)
    Abstract [en]

    Pump-controlled asymmetric cylinders need some kind ofcompensation for the difference between the in- and outlet flow.This can be done by using valves or additional pump/motors.An advantage with using valves is that only one pump/motor isrequired, but problems with mode-switch oscillations are morelikely to occur. On the other hand, cylinder areas should bewell matched with the pump/motor displacements for pump/motorcompensation if the pump/motors are fixed and connected to thesame shaft. However, this problem is avoided if the pump/motorsare individually controlled. Furthermore, with individually controlledpump/motors, it is possible to control the pressure in one ofthe cylinder chambers and the piston speed simultaneously. Thispaper is focusing on such architectures. There are several possibleconfigurations for architectures and control strategies for individuallycontrolled pump/motors, and some are compared here.Results show that one of the configurations is more efficient thanthe others, but that it is less efficient than valve-compensation (assuminglarge valves). A controller design where one pump/motoris used to control the speed and another to control the pressureis suggested. Results show that the controller should be adaptedbased on the mode of operation.

  • 163.
    Lakemond, Nicolette
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Projekt, innovationer och entreprenörskap. Linköpings universitet, Tekniska fakulteten.
    Collaborative product development with suppliers: An evolutionary perspective2014Konferensbidrag (Refereegranskat)
  • 164.
    Lakemond, Nicolette
    et al.
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Projekt, innovationer och entreprenörskap. Linköpings universitet, Tekniska fakulteten.
    Bengtsson, Lars
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling. Linköpings universitet, Tekniska högskolan.
    Laursen, K
    Tell, Fredrik
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Företagsekonomi. Linköpings universitet, Filosofiska fakulteten.
    The role of knowledge governance in open innovation,2014Konferensbidrag (Refereegranskat)
  • 165.
    Lakemond, Nicolette
    et al.
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Projekt, innovationer och entreprenörskap. Linköpings universitet, Tekniska högskolan.
    Bengtsson, Lars
    University of Gävle.
    Laursen, Keld
    Copenhagen Business School.
    Tell, Fredrik
    Uppsala universitet.
    Match & Manage: The use of knowledge matching and project management to integrate knowledge in collaborative inbound open innovation2016Ingår i: Industrial and Corporate Change, ISSN 0960-6491, E-ISSN 1464-3650, Vol. 25, nr 2, s. 333-352Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Despite mounting evidence on the potential benefits of inbound open innovation, little is known about how firms purposefully manage inflows of knowledge. We investigate the use of two knowledge governance procedures—project management and knowledge matching—in collaborative inbound open innovation. Our findings suggest that, in addition to “knowledge-precursors,” which the literature on open innovation and absorptive capacity has shown to be important for the integration of external knowledge, the firm’s choice of knowledge governance matters for innovation performance.

    Ladda ner fulltext (pdf)
    fulltext
  • 166.
    Lakemond, Nicolette
    et al.
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Projekt, innovationer och entreprenörskap. Linköpings universitet, Tekniska fakulteten.
    Franca, Adalberto
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Projekt, innovationer och entreprenörskap. Linköpings universitet, Tekniska fakulteten.
    Open Innovation Across Technology Maturity Levels: A Study of a Swedish Systems Integrator in the Aerospace Industry2016Konferensbidrag (Refereegranskat)
  • 167.
    Lakemond, Nicolette
    et al.
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Projekt, innovationer och entreprenörskap. Linköpings universitet, Tekniska fakulteten.
    Holmberg, Gunnar
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Projekt, innovationer och entreprenörskap. Linköpings universitet, Tekniska fakulteten.
    Digital Innovation in Complex Systems: Managing Critical Applications and Generativity2018Konferensbidrag (Refereegranskat)
  • 168.
    Lakemond, Nicolette
    et al.
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Projekt, innovationer och entreprenörskap. Linköpings universitet, Tekniska fakulteten.
    Holmberg, Gunnar
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Projekt, innovationer och entreprenörskap. Linköpings universitet, Tekniska fakulteten.
    Trust, Control, and Risk in Multilateral R&D Alliances: A Dynamic and Dialectic Perspective2018Ingår i: Managing Trust in Strategic Alliances / [ed] T.K. Das, Charlotte, NC: Information Age Publishing, 2018, s. 39-73Kapitel i bok, del av antologi (Refereegranskat)
  • 169.
    Lakemond, Nicolette
    et al.
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Projekt, innovationer och entreprenörskap. Linköpings universitet, Tekniska fakulteten.
    Holmberg, Gunnar
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Projekt, innovationer och entreprenörskap. Linköpings universitet, Tekniska fakulteten.
    Pettersson, Per A.
    Linköpings universitet, Institutionen för tema, Tema Kommunikation. Linköpings universitet, Filosofiska fakulteten.
    On digital innovation and critical applications: Bazaars, Cathedrals and What Else2018Konferensbidrag (Refereegranskat)
    Abstract [en]

    Digital technology is increasingly integrated in industrial applications and alters existing system architectures and innovation processes. This paper explores platform and application strategies based on an empirical case study of avionics at the Swedish firm Saab Aeronautics. The paper complements perspectives on digital innovation in relation to open source software development and systems such as mobile operating systems with applications, and points at limitations of organizational metaphors as bazaars and cathedrals. The results recognize that there is more to a city than a bazaar and a cathedral and show that the development toward digitalization necessitate industrial firms to consider safety-critical and security aspects while allowing for generativity based on recombination through system partitioning enabling different control and generativity priorities for different parts of the system.  

  • 170.
    Lakemond, Nicolette
    et al.
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Projekt, innovationer och entreprenörskap. Linköpings universitet, Tekniska fakulteten.
    Lopez-Vega, Henry
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Företagsekonomi. Linköpings universitet, Filosofiska fakulteten.
    The cogs and wheels of open innovation: The implementation of open innovation in emerging markets2016Konferensbidrag (Refereegranskat)
  • 171.
    Lakemond, Nicolette
    et al.
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Projekt, innovationer och entreprenörskap. Linköpings universitet, Tekniska fakulteten.
    Windahl, Charlotta
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Projekt, innovationer och entreprenörskap. Linköpings universitet, Tekniska fakulteten.
    Digitalization Pilots: Creating Organizational Platforms for Complex Collaborative Digital Innovation2017Konferensbidrag (Refereegranskat)
  • 172.
    Larsson, Elin
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Maskinkonstruktion. Linköpings universitet, Tekniska högskolan.
    Design och produktionsanpassning av undervattensfarkost2014Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Vid årsskiftet 2013-2014 lanserade Ocean Robotics International en undervattensfarkost med främsta syfte att filma och samla in data under ytan. För att farkosten ska kunna operera tyngdlöst i vattnet används ett flytmaterial vars utformning uppnår väldigt höga tillverkningskostnader. Därför finns det efterfrågan ifrån företaget att utveckla en farkost bättre anpassad för produktion, för att på så sätt möjliggöra minskade produktionskostnader.  Dessutom har företagets huvudsakliga kunder angett nya krav och önskemål på produkten, som kräver ett nytt utförande på farkosten för att uppnå kravuppfyllelse. Syftet med detta arbete är att göra en vidareutveckling av undervattensfarkosten som uppfyller nya krav och önskemål, samt är produktionsanpassad. Målet är att ta fram produktionsunderlag till den framtagna farkosten.

    Arbetet följde en generell, etablerad produktutvecklingsmodell av Ulrich och Eppinger (2008), som innefattade upprätthållande av en kravspecifikation, en konceptgeneringsfas med kombinerade strukturerade och fria metoder samt konceptval. Arbetsmodellen kompletterades med DFMA (Design for Manufacturing and Assembly); teori kring hur produkter kan tas fram för att anpassas för produktion.

    I arbetet undersöktes olika sätt att skapa flytkraft varvid de flesta tekniker bygger på principen inkapslad luft. På 3000 meters djup, som farkosten är utformad att operera på, är trycket ungefär 300 gånger atmosfärstrycket. Detta skapar problem för många sådana konstellationer på grund av den höga tryckskillnad som bildas mellan den inkapslade luften och det omgivande vattnet. Därför föll valet på syntaktiskt skum som företaget använder sedan tidigare, ett material med lägre densitet än vatten och som därmed avger flytkraft. Materialet är väl lämpat för avsett djup. Stabilitet i farkosten är ytterligare en faktor som är av viktigt att ta hänsyn till vid utformning, eftersom det starkt påverkar hur enkel den är att operera med. Rätt förutsättningar fås av när flytmaterial är väl utspritt i farkosten, stora avstånd mellan motorerna och farkostens form då en avlång konstruktion är att föredra. En långsmal farkost med avrundade kanter ger även fördelar i strömningsförmåga.

    Arbetet resulterade i ett koncept i detaljutförande och produktionsunderlag. För att uppfylla de nya kraven är farkosten större än föregående modell. Formerna på flytblocken är kraftigt förenklade för att på så sätt undvika maskinbearbetning som är en kostsam process. Där det är önskvärt med dubbelkrökta ytor har dessa istället skapats med hjälp av kåpa bestående av glasfiber, som tillverkas genom kompositlaminering som är en metod väl lämpad för att skapa organiska former.

    Ladda ner fulltext (pdf)
    fulltext
  • 173.
    Larsson, Elisabet
    et al.
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling.
    Nilsson, Josefin
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling.
    Kartläggning och visualisering av processer: Utveckling av styrsystem till drivlina2008Självständigt arbete på grundnivå (yrkesexamen), 20 poäng / 30 hpStudentuppsats
    Abstract [sv]

    Detta examensarbete har utförts på Scanias forskning och utvecklingsavdelning, i Söder-tälje, under hösten 2007. Dess huvudsakliga syfte är att kartlägga och visualisera arbets-processen hos avdelningen som utvecklar styrsystem för drivlinan, alltså motor och väx-ellåda. Anledningen till att en visualisering skulle tas fram var för att skapa en helhetsbild över arbetet att ha som utgångspunkt för fortsatta diskussioner om processen samt för-bättringar av den. Denna bild blir även ett sätt att samla det organisatoriska lärandet och underlätta kunskapsöverföring.

    Kartläggningen har skett genom intervjuer med cheferna på avdelningen samt genom en workshop. Information som erhölls under dessa tillfällen sammanställdes till en nulägesbeskrivning av avdelningens arbete. Många arbetsuppgifter saknade en processbeskriv-ning och de processbeskrivningar som fanns när vi inledde arbetet var inte samstämmiga. En stor brist som vi fann under kartläggningen var att kravhantering saknas i stor ut-sträckning i avdelningens arbete. Detta ställer till ett flertal problem vid planering och resurssäkring av projekt, men även när det handlar om att verifiera programvaran som utvecklas. Det finns även ett behov av att klargöra beslutsprocessen på avdelningen.

    Utifrån den information vi fick från kartläggningen och teorier som behandlar ämnena process, produktutveckling samt mjukvaruutveckling har en analys gjorts av det nuva-rande arbetssättet. Vi inledde med att definiera det system som avdelningen utgör för att sedan identifiera processer utifrån de beskrivningar som gavs av cheferna. Här började även arbetet med att ta fram förslag på nya processer som behövs för att åtgärda de pro-blem som vi funnit under kartläggningens gång. De nya och gamla processerna struktu-rerades sedan genom att försöka hitta en entydighet mellan dem och placera dem i olika kategorier beroende på vad syftet med processen var.

    Efter att processerna strukturerats ritades huvudprocessen upp. Resultatet är en visuali-sering av avdelningens huvudprocess med den första nivån av delprocesser beskrivna. Den största förändringen är att två nya delprocesser har tagits fram i början av arbets-processen.

    Den första av dessa behandlar starten av projekt på NE. Syftet med processen är att få en bättre nedbrytning av de krav som kommer från projektkontoret, för att NE ska få större klarhet i vad som ska åstadkommas. Sättet att göra detta på är att samla berörda personer vid ett tillfälle för att diskutera kraven samt att planera projektet för NE:s del. Resultatet av ett sådant tillfälle blir förhoppningsvis en större förståelse inom organisa-tionen om vad som ska göras, men även att objektledarna utifrån detta kan sammanställa en bra objektdefinition.

    Nästa nya delprocess behandlar planeringen av framtagningen av mjukvara. Det handlar om hur beslut ska tas för vilka funktioner och ändringar som ska hinna utvecklas till en viss tidpunkt. Vi har sett ett stort behov av att klargöra denna process och ge den en större roll i huvudprocessen. Vi har gett ett förslag på hur beslutsprocessen skulle kunna se ut, men det finns fortfarande ett behov av att vidareutveckla den och skapa samför-stånd runt den.

    Ladda ner fulltext (pdf)
    FULLTEXT01
  • 174.
    Larsson, Felix
    et al.
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluida och mekatroniska system.
    Johansson, Christian
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluida och mekatroniska system.
    Digital hydraulic actuator for flight control2019Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    In aviation industry, one of the most important aspects is weight savings. This since with a lowered weight, the performance of the aircraft can be increased together with increased fuel savings and thus lowered running costs. One way of saving weight is to reduce energy consumption, since with lowered energy consumption, lowered mass of fuel is required etc.

    Most aircraft are today maneuvered with hydraulic systems due to its robustness and power density. It is the primary source of power for primary and secondary flight controls. The control of a conventional system which is using proportional valves is done by altering flow by restricting it to the extent where the desired output is achieved, which implies heat losses since the full performance of its supply is wasted through the valve.

    In previous research, more energy efficient hydraulic systems called digital hydraulics has been investigated. In difference with conventional hydraulics, digital hydraulics uses low cost, high frequency on/off valves, which either are fully opened, or fully closed, instead of proportional valves to achieve the desired output. With this comes the benefit of no energy losses due to leakage and restriction control.

    The downsides with digital hydraulics is the controlabillity. One way of controlling it is by using several pressure sources which outputs different pressure levels. By using the on/off valves in different combinations, different outputs can be achieved in a discrete manner.

    In this thesis, the aim was to remove the impact of the discrete force steps which are present in digital hydraulics by creating concepts with hybrid solutions containing both digital hydraulics and restrictive control.

    Three concepts were developed and investigated using simulation. The energy consumption and performance was analysed and compared with a reference model, the concepts redundancy compared to conventional systems was discussed and finally the concepts were tested with an aircraft simulation model.

    The concepts were found to reduce the energy consumption with different magnitude depending on the load cycle. The performance was found to be almost as good as the reference model. The redundancy compared with conventional systems should be possible to maintain with slight modifications, but further investigation is needed.

    It was found that one of the most important aspects regarding energy consumption is which combination of supply pressures is used to supply the system since it influences leakage and flow due to compression.

    Ladda ner fulltext (pdf)
    Digital_Hydraulic_Actuator_For_Flight_Control
  • 175.
    Larsson, Karin
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Industriell miljöteknik. Linköpings universitet, Tekniska högskolan.
    Inventering och bedömning av förorenade områden inom division Energi, Tekniska Verken i Linköping2013Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Det övergripande syftet med detta examensarbete är att utreda begreppet miljöskuld och vad det innebär för ett företag. Arbetet har utförts på uppdrag av Tekniska verken, division Energi. Man vill nu att förorenade områden skall inventeras och sammanställas. Vidare skall en hållbar riskbedömning och ansvarsutredning utföras på de aktuella områdena. Slutligen skall prioriterade områden lyftas fram och åtgärdsförslag presenteras.

     

    Miljöskuldsbegreppet presenterades 1992 av Arne Jarnelöv. Miljöskuld är återställning- och/eller reparationskostnader för miljöskador. I den ursprungliga innebörden av begreppet beaktade man inte vem som åstadkommit miljöskadan utan man betraktade miljöskulder som en mänsklighetens skuld som vi hade till nästa generation. För ett företag betyder en miljöskuld att man har ett juridiskt ansvar enligt miljölagstiftning. Det innebär även att åtgärdskostnaden skall bokföras som en skuld. Miljöskulden kan även ha betydelse i ett företags hållbarhetsarbete. Förorenade områden kan innebära att företaget ses som utövare av miljöfarlig verksamhet.

     

    Inventeringen och sammanställningen visar att division Energi har två fastigheter med stor föroreningsproblematik. Det är Kraftvärmeverkets fastighet som har en central placering i Linköping. Det andra området är en gammal deponi belägen i norra utkanten av Linköping. Vid kraftvärmeverkets fastighet drev man gasverk under 60 år som har bidragit till omfattande föroreningar. På området har kreosotimpregnerade elstolpar lagrats på två olika platser. Troligtvis kan det finnas kvar stora mängder kreosotföroreningar under den asfalterade bränsleplanen. 30-50 m under fastigheten ligger ett 90 000 m³ stort bergrum som använts för lagring av högsvavlig tjockolja. Sedan början av 1990- talet används inte bergrummet men uppskattningsvis finns över 2 000 m³ olja kvar på vattenytan eller i bergsprickor. Bergrummet är oinklätt vilket betyder att oljan förvarades direkt mot berget på en vattenbädd. Vattenytan hålls idag nedsänkt för att förhindra att oljeföroreningar sprids. Att avveckla och sanera bergrum är komplicerat och kan ta lång tid. Bolaget måste lämna fastigheten inom de närmsta 30 åren vilket betyder att man behöver en åtgärdsplan för olika föroreningssituationer.

     

    Kallerstadsdeponin är en deponi som drevs från 1955 till 1973. Under de första åren deponerades stora mängder hushålls och industriavfall. 1958 byggdes sopförbränning på Kraftvärmeverkets fastighet och deponeringen begränsades till sådant som inte brann. Deponin ligger i en gammal lertäkt vilket minskar risk för spridning. Deponin var i kommunal ägo och drift fram till 1961. Tekniska verken övertog sedan ägande och drift. Det är i första hand den som deponerat avfallet som är ansvarig och i andra hand är det markägaren.

     

    På flera av vattenkraftstationerna har sediment och mark förorenats av andra verksamheter. Vid några fastigheter har oljeläckage skett vilka har sanerats till idag godkända nivåer.

     

    Det är av stor vikt för företag att få en samlad bild av sina miljöskulder då de förutom den ekonomiska belastningen även kan betyda att man vid exempelvis grävningsarbeten i förorenad mark ses som utövare av miljöfarlig verksamhet. I förlängningen bör grävningsrutiner upprättas för alla förorenade fastigheter inom division Energi. Sanering av bergrum kan ta lång tid. En förundersökning bör därför inledas så snart som möjligt. En grävningsrutin bör upprättas för KV1- fastighten för att minska risken för spridning av föroreningar. Vid Kallerstaddeponin bör dialog föras mellan kommun och Tekniska verken och ansvarförhållandet mellan parterna avgöras.

    Ladda ner fulltext (pdf)
    Inventering och bedömning av förorenade områden inom division Energ
  • 176. Beställ onlineKöp publikationen >>
    Larsson, L. Viktor
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluida och mekatroniska system. Linköpings universitet, Tekniska fakulteten.
    Control of Hybrid Hydromechanical Transmissions2019Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    This thesis deals with control aspects of complex hybrid hydromechanical transmissions for heavy mobile working machines. Control problems are identified and solved to facilitate the implementation and use of these systems.

    Fuel prices and environmental concerns have increased the interest in hybrid hydromechanical transmissions for heavy mobile working machines. Hybridisation, the introduction of a secondary energy source in the transmission, offers attractive improvements in terms of both fuel efficiency and performance. These improvements are, in turn, enabled by software control. A complex transmission architecture has several components that need to interact in a stable manner. In addition, optimal utilisation of the added energy source is required to maximise fuel savings. Meanwhile, there is a strong trend towards automation, where many of the operator’s difficult control tasks need to be managed by computers. Sophisticated control strategies are therefore needed, along with a deeper understanding of dynamic properties.

    Previous research on the control of hybrid hydromechanical transmissions has primarily focussed on on-road applications. The working conditions of heavy working machines place different requirements on the transmission, which is also reflected in the control strategy.

    This thesis highlights the importance of fast response of the variable displacement pump/motors used in hybrid hydromechanical transmissions. Their central position in the interface between hydraulics and mechanics makes their dynamic performance a limiting factor both for the stability of the transmission control loops and in the realisation of smooth mode shifts in multiplemode transmissions. Dynamic models and control strategies for displacement actuators are derived and validated in simulation and experiments. A linear model for dynamic analysis of a general hybrid hydromechanical transmission for heavy working machines is derived and a powertrain control strategy based on decoupled control is proposed. The strategy is verified in simulations and experiments in hardware-in-the-loop simulations, and may be used in a working machine with or without a human operator.

    Delarbeten
    1. Mode Shifting in Hybrid Hydromechanical Transmissions
    Öppna denna publikation i ny flik eller fönster >>Mode Shifting in Hybrid Hydromechanical Transmissions
    2015 (Engelska)Ingår i: ASME/BATH 2015 Symposium on Fluid Power and Motion Control, ASME Press, 2015, s. 13-Konferensbidrag, Publicerat paper (Refereegranskat)
    Abstract [en]

    Demands for low cost sustainable solutions have increased the use of and interest in complex hydromechanical transmissions for heavy off-road vehicles. In transmissions with multiplemodes, an important condition is to maintain the tractive force during the mode shifting event. For hybrid hydromechanical transmissions, with a direct connection to a hydraulic accumulator, the impressed system pressure caused by the hydraulic accumulator has not yet been observed to interfere with this condition. In this paper, a black box model approach is used to modify the hydraulic system after obtaining knowledge regarding how it is affected by a mode shift. A comparative study is carried out where a full vehicle model of a mobile working machine is simulated with two different hydraulic systems. The results show that different system solutions imply different demands on the included components, and that the mode shifting event is not a negligible factor in heavy hydraulic hybrid vehicles.

    Ort, förlag, år, upplaga, sidor
    ASME Press, 2015
    Nyckelord
    Mode shifting, hydromechanical transmissions, fluid power, heavy construction machinery
    Nationell ämneskategori
    Annan maskinteknik
    Identifikatorer
    urn:nbn:se:liu:diva-126556 (URN)10.1115/FPMC2015-9583 (DOI)000373970500045 ()978-0-7918-5723-6 (ISBN)
    Konferens
    ASME/BATH 2015 Symposium on Fluid Power and Motion Control, Chicago, Illinois, USA, October 12–14, 2015
    Projekt
    Research on Hydromechanical Transmissions and Hybrid Motion systems, RHYTHM
    Forskningsfinansiär
    Energimyndigheten, P39367-1
    Tillgänglig från: 2016-03-30 Skapad: 2016-03-30 Senast uppdaterad: 2019-08-21
    2. Modelling of the Swash Plate Control Actuator in an Axial Piston Pump for a Hardware-In-the-Loop Simulation Test Rig
    Öppna denna publikation i ny flik eller fönster >>Modelling of the Swash Plate Control Actuator in an Axial Piston Pump for a Hardware-In-the-Loop Simulation Test Rig
    2016 (Engelska)Ingår i: Proceedings of the 9th FPNI Ph.D. Symposium on Fluid Power, FPNI2016, ASME Press, 2016, artikel-id UNSP V001T01A044Konferensbidrag, Publicerat paper (Refereegranskat)
    Abstract [en]

    Hydraulic hybrid system solutions are promising in the quest for energy efficiency in heavy construction machines. Hardware-in-the-loop simulations, where hardware is included in software simulations in real time, may be used to facilitate the development process of these systems without the need to build expensive prototypes. In this paper, the displacement actuator of a prototype pump used in a hardware-in-the-loop simulation test rig is modelled and validated against hardware, in order to draw conclusions regarding its dynamic behaviour in a future control design. The results show that the dynamic response of the modelled displacement actuator is mainly determined by the system pressure as well as the response and geometry of the control valve.

    Ort, förlag, år, upplaga, sidor
    ASME Press, 2016
    Nationell ämneskategori
    Maskinteknik
    Identifikatorer
    urn:nbn:se:liu:diva-133328 (URN)10.1115/FPNI2016-1570 (DOI)000398986900044 ()978-0-7918-5047-3 (ISBN)
    Konferens
    The 9th FPNI Ph.D. Symposium on Fluid Power
    Projekt
    Research on Hydromechanical Transmissions and Hybrid Motion systems, RHYTHM
    Forskningsfinansiär
    Energimyndigheten, P39367-1
    Anmärkning

    The authors would like to thank the Swedish Energy Agency for contributing funds for the research project. Thanks also go to Bosch Rexroth for providing the prototype machines.

    Tillgänglig från: 2016-12-20 Skapad: 2016-12-20 Senast uppdaterad: 2020-09-04
    3. Displacement Control Strategies of an In-Line Axial-Piston Unit
    Öppna denna publikation i ny flik eller fönster >>Displacement Control Strategies of an In-Line Axial-Piston Unit
    2017 (Engelska)Ingår i: Proceedings of 15:th Scandinavian International Conference on Fluid Power, June 7-9, 2017, Linköping, Sweden / [ed] Petter Krus, Liselott Ericson and Magnus Sethson, Linköping: Linköping University Electronic Press, 2017, Vol. 144, s. 244-253Konferensbidrag, Publicerat paper (Refereegranskat)
    Abstract [en]

    The need for efficient propulsion in heavy vehicles has led to an increased interest in hybrid solutions. Hydraulic hybrids rely on variable hydraulic pumps/motors to continuously convert between hydraulic and mechanical power. This process is carried out via the implementation of secondary control which, in turn, is dependent on a fast displacement controller response. This paper reports on a study of a prototype axial piston pump of the in-line type, in which the displacement is measured with a sensor and controlled using a software-based controller. A pole placement control approach is used, in which a simple model of the pump is used to parametrise the controller using desired resonance and damping of the closed loop controller as input. The controller’s performance is tested in simulations and hardware tests on the prototype unit. The results show that the pole placement approach combined with a lead-compensator controller architecture is flexible, easy to implement and is able to deliver a fast response with high damping. The results will in the future be used in further research on full-vehicle control of heavy hydraulic hybrids.

    Ort, förlag, år, upplaga, sidor
    Linköping: Linköping University Electronic Press, 2017
    Serie
    Linköping Electronic Conference Proceedings, ISSN 1650-3686, E-ISSN 1650-3740 ; 144
    Nyckelord
    Hydraulic hybrids, displacement control, pole placement
    Nationell ämneskategori
    Maskinteknik
    Identifikatorer
    urn:nbn:se:liu:diva-139854 (URN)10.3384/ecp17144244 (DOI)9789176853696 (ISBN)
    Konferens
    The 15th Scandinavian International Conference on Fluid Power, SICFP’17, June 7-9, 2017, Linköping, Sweden
    Tillgänglig från: 2017-08-17 Skapad: 2017-08-17 Senast uppdaterad: 2019-08-21Bibliografiskt granskad
    4. A General Approach to Low-Level Control of Heavy Complex Hybrid Hydromechanical Transmissions
    Öppna denna publikation i ny flik eller fönster >>A General Approach to Low-Level Control of Heavy Complex Hybrid Hydromechanical Transmissions
    2018 (Engelska)Ingår i: BATH/ASME 2018 Symposium on Fluid Power and Motion Control, ASME Press, 2018Konferensbidrag, Publicerat paper (Refereegranskat)
    Abstract [en]

    This paper focuses on the low-level control of heavy complex hydraulic hybrids, taking stability and the dynamic properties of the included components into account. A linear model which can describe a high number of hybrid configurations in a straightforward manner is derived and used for the development of a general multiple input multiple output (MIMO) decoupling control strategy. This strategy is tested in non-linear simulations of an example vehicle and stability requirements for the low-level actuators are derived. The results show that static decoupling may be used to simplify the control problem to three individual loops controlling pressure, output speed and engine speed. In particular, the pressure and output speed loops rely on fast displacement controllers for stability. In addition, it was found that the decoupling is facilitated if the hydrostatic units have equal response. The low-level control of heavy complex hydraulic hybrids may thus imply other demands on actuators than what is traditionally assumed.

    Ort, förlag, år, upplaga, sidor
    ASME Press, 2018
    Nyckelord
    Control, Multiple input multiple output control, heavy hydraulic hybrids, hydromechanical transmissions
    Nationell ämneskategori
    Maskinteknik
    Identifikatorer
    urn:nbn:se:liu:diva-154306 (URN)10.1115/FPMC2018-8877 (DOI)000460491500042 ()2-s2.0-85058056485 (Scopus ID)978-0-7918-5196-8 (ISBN)
    Konferens
    BATH/ASME 2018 Symposium on Fluid Power and Motion Control, Bath, United Kingdom, September 12-14, 2018
    Forskningsfinansiär
    Energimyndigheten, P39367-2
    Anmärkning

    Funding agencies: Swedish Energy Agency

    Tillgänglig från: 2019-02-04 Skapad: 2019-02-04 Senast uppdaterad: 2021-08-21Bibliografiskt granskad
    5. Low-Level Control of Hybrid Hydromechanical Transmissions for Heavy Mobile Working Machines
    Öppna denna publikation i ny flik eller fönster >>Low-Level Control of Hybrid Hydromechanical Transmissions for Heavy Mobile Working Machines
    2019 (Engelska)Ingår i: Energies, E-ISSN 1996-1073, Vol. 12, nr 9, artikel-id 1683Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    Fuel efficiency has become an increasingly important property of heavy mobile working machines. As a result, Hybrid Hydromechanical Transmissions (HMTs) are often considered for the propulsion of these vehicles. The introduction of hybrid HMTs does, however, come with a number of control-related challenges. To date, a great focus in the literature has been on high-level control aspects, concerning optimal utilization of the energy storage medium. In contrast, the main topic of this article is low-level control, with the focus on dynamic response and the ability to realize requested power flows accurately. A static decoupled Multiple-Input-Multiple-Output (MIMO) control strategy, based on a linear model of a general hybrid HMT, is proposed. The strategy is compared to a baseline approach in Hardware-In-the-Loop (HWIL) simulations of a reference wheel loader for two drive cycles. It was found that an important benefit of the decoupled control approach is that the static error caused by the system’s cross-couplings is minimized without introducing integrating elements. This feature, combined with the strategy’s general nature, motivates its use for multiple-mode transmissions in which the transmission configuration changes between the modes. 

    Ort, förlag, år, upplaga, sidor
    MDPI, 2019
    Nyckelord
    hydromechanical transmissions, hybridization, control, construction machinery; decoupled control, hardware-in-the-loop
    Nationell ämneskategori
    Annan maskinteknik
    Identifikatorer
    urn:nbn:se:liu:diva-157504 (URN)10.3390/en12091683 (DOI)000469761700099 ()
    Forskningsfinansiär
    Energimyndigheten, P39367-2
    Anmärkning

    Funding agencies: Swedish Energy Agency (Energimyndigheten) [P39367-2]

    Tillgänglig från: 2019-06-14 Skapad: 2019-06-14 Senast uppdaterad: 2023-08-28Bibliografiskt granskad
    Ladda ner fulltext (pdf)
    fulltext
    Ladda ner (png)
    presentationsbild
  • 177.
    Larsson, L. Viktor
    et al.
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluida och mekatroniska system. Linköpings universitet, Tekniska fakulteten.
    Ericson, Liselott
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluida och mekatroniska system. Linköpings universitet, Tekniska fakulteten.
    Uebel (Pettersson), Karl
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluida och mekatroniska system. Linköpings universitet, Tekniska fakulteten. Volvo Construction Equipment.
    Krus, Petter
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluida och mekatroniska system. Linköpings universitet, Tekniska fakulteten.
    Low-Level Control of Hybrid Hydromechanical Transmissions for Heavy Mobile Working Machines2019Ingår i: Energies, E-ISSN 1996-1073, Vol. 12, nr 9, artikel-id 1683Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Fuel efficiency has become an increasingly important property of heavy mobile working machines. As a result, Hybrid Hydromechanical Transmissions (HMTs) are often considered for the propulsion of these vehicles. The introduction of hybrid HMTs does, however, come with a number of control-related challenges. To date, a great focus in the literature has been on high-level control aspects, concerning optimal utilization of the energy storage medium. In contrast, the main topic of this article is low-level control, with the focus on dynamic response and the ability to realize requested power flows accurately. A static decoupled Multiple-Input-Multiple-Output (MIMO) control strategy, based on a linear model of a general hybrid HMT, is proposed. The strategy is compared to a baseline approach in Hardware-In-the-Loop (HWIL) simulations of a reference wheel loader for two drive cycles. It was found that an important benefit of the decoupled control approach is that the static error caused by the system’s cross-couplings is minimized without introducing integrating elements. This feature, combined with the strategy’s general nature, motivates its use for multiple-mode transmissions in which the transmission configuration changes between the modes. 

    Ladda ner fulltext (pdf)
    energies-12-01683
  • 178.
    Larsson, L. Viktor
    et al.
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluida och mekatroniska system. Linköpings universitet, Tekniska fakulteten.
    Pettersson, Karl
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluida och mekatroniska system. Linköpings universitet, Tekniska fakulteten. Volvo Construction Equipment.
    Krus, Petter
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluida och mekatroniska system. Linköpings universitet, Tekniska fakulteten.
    Mode Shifting in Hybrid Hydromechanical Transmissions2015Ingår i: ASME/BATH 2015 Symposium on Fluid Power and Motion Control, ASME Press, 2015, s. 13-Konferensbidrag (Refereegranskat)
    Abstract [en]

    Demands for low cost sustainable solutions have increased the use of and interest in complex hydromechanical transmissions for heavy off-road vehicles. In transmissions with multiplemodes, an important condition is to maintain the tractive force during the mode shifting event. For hybrid hydromechanical transmissions, with a direct connection to a hydraulic accumulator, the impressed system pressure caused by the hydraulic accumulator has not yet been observed to interfere with this condition. In this paper, a black box model approach is used to modify the hydraulic system after obtaining knowledge regarding how it is affected by a mode shift. A comparative study is carried out where a full vehicle model of a mobile working machine is simulated with two different hydraulic systems. The results show that different system solutions imply different demands on the included components, and that the mode shifting event is not a negligible factor in heavy hydraulic hybrid vehicles.

  • 179.
    Larsson, Viktor
    et al.
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluida och mekatroniska system. Linköpings universitet, Tekniska högskolan.
    Larsson, L. Viktor
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluida och mekatroniska system. Linköpings universitet, Tekniska högskolan.
    Simulation and Testing of Energy Efficient Hydromechanical Drivlines for Construction Equipment2014Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Increased oil prices and environmental issues have increased a need of loweringthe emissions from and the fuel consumption in heavy construction machines. Anatural solution to these issues is a lowered input power through downsizing ofthe engine. This implies a demand on higher transmission efficiency, in order tominimize the intrusion on vehicle performance. More specifically, alternatives tothe conventional torque converter found in heavier applications today, must beinvestigated. One important part of this is the task of controlling the transmissionwithout jeopardising the advantages associated with the torque converter, such asrobustness and controllability.In this thesis, an alternative transmission concept for a backhoe loader is investigated.The studied concept is referred to as a 2-mode Jarchow power-splittransmission, where a mechanical path is added to a hydrostatic transmission inorder to increase transmission efficiency. The concept is evaluated in computerbased simulations as well as in hardware-in-the-loop simulations, where a physicalhydrostatic transmission is exposed for the loads caused by the vehicle duringvarying conditions. The loads are in turn simulated according to developed modelsof the mechanical parts of the vehicle drive line.In total, the investigated concept can be used instead of the torque converterconcept, if the hydrostatic transmission is properly controlled. The results alsoshow that there is a high possibility that the combustion engine in the backhoeloader can be downsized from 64 kW to 55 kW, which would further increase thefuel savings and reduce the emissions.

    Ladda ner fulltext (pdf)
    Simulation and Testing of Energy Efficient Hydromechanical Drivlines for Construction Equipment
  • 180.
    Leong, Elaine
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Industriell miljöteknik.
    Water Situation In China - Crisis Or Business As Usual?2013Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Several studies indicates China is experiencing a water crisis, were several regions are suffering of severe water scarcity and rivers are heavily polluted. On the other hand, water is used inefficiently and wastefully: water use efficiency in the agriculture sector is only 40% and within industry, only 40% of the industrial wastewater is recycled. However, based on statistical data, China’s total water resources is ranked sixth in the world, based on its water resources and yet, Yellow River and Hai River dries up in its estuary every year. In some regions, the water situation is exacerbated by the fact that rivers’ water is heavily polluted with a large amount of untreated wastewater, discharged into the rivers and deteriorating the water quality. Several regions’ groundwater is overexploited due to human activities demand, which is not met by local. Some provinces have over withdrawn groundwater, which has caused ground subsidence and increased soil salinity. So what is the situation in China? Is there a water crisis, and if so, what are the causes?

    This report is a review of several global water scarcity assessment methods and summarizes the findings of the results of China’s water resources to get a better understanding about the water situation. All of the methods indicated that water scarcity is mainly concentrated to north China due to rapid growth, overexploitation from rivers and reduced precipitation. Whereas, South China is indicated as abundant in water resources, however, parts of the region are experiencing water scarcity due to massive dam constructions for water storage and power production. Too many dam constructions in a river disrupts flow of the river water and pollutants are then accumulated within floodgates.

    Many Chinese officials and scholars believe that with economic growth comes improved environmental quality when the economy has reached to a certain of per-capita level. However, with the present water situation it is not sustainable or possible for China to keep consuming and polluting its water resources. Improvement of environmental quality does not come automatically with increased income, and policies, laws and regulations are needed in order to stop further deterioration of the environment.

    China’s water situation is not any news and the key factor is human activities, but the question is how to solve it. China’s water crisis is much more complex than over exploitation of groundwater and surface water. There are three water issues in China:  “too much water – floods, too little water – droughts, and too dirty water – water pollution” (Jun & Chen, 2001). Thus, solving China’s water crisis is a huge challenge to solve without negatively affecting the economic growth.

     

    Ladda ner fulltext (pdf)
    Water Situation In China - Crisis Or Business As Usual?
  • 181.
    Liljengren, Erik
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Industriell träteknik. Linköpings universitet, Institutionen för ekonomisk och industriell utveckling.
    Adaptive sawing: - Yield of a concept in reality2009Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Limfog är basen för de massivträmöbler som görs av IKEA:s helägda leverantör Swedwood.Limfog består av lameller som kan produceras på olika sätt. Oavsett produktionsteknik görs deav brädor som kommer från ett sågverk. På sågverket finns det också sågsätt för att såga utbrädor ur stockar. Det här examensarbetet behandlar konceptet adaptiv sågning och dessimplementering på Swedwoods anläggning i Kostomuksha. Den grundläggande idén medkonceptet är att höja utbytet på råvaran. Detta uppnås bland annat genom att så lite som möjligtkantas bort på brädorna i sågverket. Brädorna sågas upp med vad man kan kalla genomsågning.När brädorna sedan förts till limfogsfabriken scannas de så att så mycket som möjligt ska kunnafås ut av varje bräda i form av lameller. Lamellerna som sågats ut kapas sedan upp i olikastorleksklasser beroende på kvalitet. Dessa limmas sedan ihop till limfog. Syftet med det härexamensarbetet är att ta fram utbytet från stock till färdig limfog för stockklasserna 135 – 148mm och 110 – 120 mm. Dessutom ska problemfaktorer identifieras och utbytet om möjligt höjas.För att uppnå detta syfte var det nödvändigt att ha säkra siffror för alla inblandade volymer isamtliga skeden. Stockarnas volym gav av en mätram vid timmersorteringen. Mycket kraft lasdärför ner för att säkerställa att dessa siffror var trovärdiga. Stockarna i den mindrediameterklassen mättes istället för hand och volym beräknades utifrån mätningarna. Stockarnasågades sedan på sågverket. Produktionshastigheten under sågningarna var låg och en delproblem i jämförelse med när sågning sker på mer traditionellt vis kunde noteras. Avsaknaden avkantning var huvudorsaken till dessa problem. Sågverkslinan visade sig vara olämplig för attsåga den mindre stockklassen, men kunde hantera stockar med en diameter på 135 – 148 mm.Utbytet för dessa var i linje med vad som kunde förväntas.I lamellproduktionslinjen kunde en del smärre produktionsproblem noteras och brädorna från defyra olika omgångarna av 135 – 148 mm stockar fick olika utbyte mest beroende på skillnader iråvarukvalitet. Utbytet från stock till limfog varierade från 17,6 % till 21,5 % och låg i snitt på19,3 %. Detta utbyte var lägra än vad som uppnåtts för adaptiv sågning på andra platser vidtidigare tester. De testerna utfördes dock på andra diameterklasser och det är därför svårt att raktav jämföra siffrorna. Dessutom kan råvaran ha varit något annorlunda. För att se hur mycketutbytet kunde höjas om andra lamellbredder användes förutom bara 46 mm, gjordessimuleringar. Totalutbytet kunde då höjas till i snitt 20,9 % i fall lamellbredderna 46, 55 och 60mm användes.En likadan simulering gjordes på materialet som producerades från diameterklassen 110 – 120mm. Totalutbytet för denna klass steg från 19,4 % till 22,4 % när fler lamellbredder användes.Eftersom det fanns viss oro att lamellerna skulle hålla lägre kvalitet övervakades de ilimfogsproduktionen. Oron visade sig obefogad. Att producera lameller från den diameterklassenär dock inte idealt eftersom den producerade volymen blir så liten.

    Ladda ner fulltext (pdf)
    Adaptive sawing master
  • 182.
    Liljengren, Erik
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Industriell träteknik. Linköpings universitet, Institutionen för ekonomisk och industriell utveckling.
    Adaptive sawing: Yield of a concept in reality2009Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Limfog är basen för de massivträmöbler som görs av IKEA:s helägda leverantör Swedwood.Limfog består av lameller som kan produceras på olika sätt. Oavsett produktionsteknik görs de av brädor som kommer från ett sågverk. På sågverket finns det också sågsätt för att såga utbrädor ur stockar. Det här examensarbetet behandlar konceptet adaptiv sågning och dessimplementering på Swedwoods anläggning i Kostomuksha. Den grundläggande idén med konceptet är att höja utbytet på råvaran. Detta uppnås bland annat genom att så lite som möjligtkantas bort på brädorna i sågverket. Brädorna sågas upp med vad man kan kalla genomsågning.När brädorna sedan förts till limfogsfabriken scannas de så att så mycket som möjligt ska kunnafås ut av varje bräda i form av lameller. Lamellerna som sågats ut kapas sedan upp i olikastorleksklasser beroende på kvalitet. Dessa limmas sedan ihop till limfog. Syftet med det härexamensarbetet är att ta fram utbytet från stock till färdig limfog för stockklasserna 135 – 148mm och 110 – 120 mm. Dessutom ska problemfaktorer identifieras och utbytet om möjligt höjas.

    För att uppnå detta syfte var det nödvändigt att ha säkra siffror för alla inblandade volymer isamtliga skeden. Stockarnas volym gav av en mätram vid timmersorteringen. Mycket kraft lasdärför ner för att säkerställa att dessa siffror var trovärdiga. Stockarna i den mindrediameterklassen mättes istället för hand och volym beräknades utifrån mätningarna. Stockarnasågades sedan på sågverket. Produktionshastigheten under sågningarna var låg och en delproblem i jämförelse med när sågning sker på mer traditionellt vis kunde noteras. Avsaknaden avkantning var huvudorsaken till dessa problem. Sågverkslinan visade sig vara olämplig för attsåga den mindre stockklassen, men kunde hantera stockar med en diameter på 135 – 148 mm.Utbytet för dessa var i linje med vad som kunde förväntas.

    I lamellproduktionslinjen kunde en del smärre produktionsproblem noteras och brädorna från defyra olika omgångarna av 135 – 148 mm stockar fick olika utbyte mest beroende på skillnader iråvarukvalitet. Utbytet från stock till limfog varierade från 17,6 % till 21,5 % och låg i snitt på19,3 %. Detta utbyte var lägra än vad som uppnåtts för adaptiv sågning på andra platser vidtidigare tester. De testerna utfördes dock på andra diameterklasser och det är därför svårt att raktav jämföra siffrorna. Dessutom kan råvaran ha varit något annorlunda. För att se hur mycketutbytet kunde höjas om andra lamellbredder användes förutom bara 46 mm, gjordessimuleringar. Totalutbytet kunde då höjas till i snitt 20,9 % i fall lamellbredderna 46, 55 och 60mm användes.

    En likadan simulering gjordes på materialet som producerades från diameterklassen 110 – 120mm. Totalutbytet för denna klass steg från 19,4 % till 22,4 % när fler lamellbredder användes.Eftersom det fanns viss oro att lamellerna skulle hålla lägre kvalitet övervakades de ilimfogsproduktionen. Oron visade sig obefogad. Att producera lameller från den diameterklassenär dock inte idealt eftersom den producerade volymen blir så liten.

    Ladda ner fulltext (pdf)
    Adaptive sawing master thesis
  • 183.
    Lind, Sebastian
    et al.
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Industriell Produktion. Linköpings universitet, Tekniska fakulteten.
    Olsson, David
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Industriell Produktion. Linköpings universitet, Tekniska fakulteten.
    Sundin, Erik
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Industriell Produktion. Linköpings universitet, Tekniska fakulteten.
    Exploring inter-organizational relationships in automotive component remanufacturing2014Ingår i: Journal of Remanufacturing, ISSN 2210-4690, Vol. 4, nr 5Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    One of the industry sectors with the longest history in remanufacturing is the automotive industry. Remanufactured parts include brake calipers, engines, servo pumps and alternators. A big challenge for automotive component remanufacturers is to achieve a steady flow of cores (parts that are used for remanufacturing). This flow could be secured by making agreements with core suppliers, such as an original equipment manufacturer (OEM), a core broker or another actor in the market. The remanufacturer can also choose to collect the cores without closer collaboration with the core suppliers. One crucial aspect in choosing how to collect the cores is that it has to be lucrative.

    The aim of this paper is to explore how remanufacturers manage their inter-organizational relationships in the closed-loop supply chain. A case study was conducted within the European research project ‘CAN-REMAN’, and empirical data was collected from six participating companies within the project, all European small and medium-sized (SME) remanufacturers of automotive components. These companies were investigated, and their relationships, defined in earlier research with core suppliers, were evaluated.

    A key finding of the research is that the most problematic parameter with supplier relationships is to receive the ordered quantity of cores from the supplier. This parameter is continually ranked as one of the most important, and the participating companies also claim to have problems with it. A successful relationship and take-back system was pointed out by one of the companies to never be the owner of the actual cores, and only perform the remanufacturing activity (service) for an OEM. This new relationship, called reman-contract, is where the OEM owns the core and the remanufacturer just performs remanufacturing including some sorting and storing. It was found that with this kind of relationship, the ordered quantity of cores was fulfilled to a higher degree, and thus the challenge of achieving a steady flow of cores was met.

    Ladda ner fulltext (pdf)
    fulltext
  • 184.
    Lindahl, Olof
    et al.
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling.
    Hasanogullari, Yusuf
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling.
    Management Training at Cypress Security: A Case Study Application2007Självständigt arbete på avancerad nivå (magisterexamen), 20 poäng / 30 hpStudentuppsats
    Abstract [en]

    Many Small and Medium-sized Enterprises (SMEs) today face problems with growth and profitability due to lack of management training within the managerial staff. This study aims to create a holistic model for how to construct a Management Training Plan for such companies and test this model on a case company.

    The study found four main phases in the creation of a training plan, and thus, the model consists of four parts. The first part deals with the motivation of the trainees to go through with the training. The second part deals with deciding the content of the training plan. The third part looks at how the training plan should be designed. The fourth part looks at how to evaluate the training after it has been conducted.

    The main findings are that the most interesting areas of training for the managers at Cypress Security are customer communication and financial management. The training should be a mixture between group discussions and self-study material.

    We believe the results in this study should prove useful when constructing training programs for other companies since the model can be applied to almost any type of company. By providing specialized management training of this kind, SMEs reduce the need for hiring and recruiting managers with academic background and allows them to recruit from within.

    Ladda ner fulltext (pdf)
    FULLTEXT01
  • 185.
    Linderborg, Julia
    et al.
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling.
    Joelsson, Emma
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling.
    Samverkande system för saffranslökshantering för inomhusproduktion i Sverige2023Självständigt arbete på grundnivå (kandidatexamen), 12 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Currently, all commercial cultivation of saffron takes place in outdoor fields, and the work is largely carried out manually. The company BlueRedGold is a Swedish startup that aims to revolutionize commercial saffron cultivation by developing a method to grow saffron indoors year-round using fully automated processes. BlueRedGold has enlisted the help of the project group to which this thesis belongs in order to develop automated methods for preparing saffron bulbs for planting. The preparation of saffron bulbs includes peeling, sieving, and sorting, and this particular thesis aims to ensure functional requirements for these three steps of preparation.

    Through literature review, the thesis collects theory related to collaborative systems, food safety, and materials. This theory then serves as the basis for designing a comprehensive system for peeling, sieving, and sorting saffron bulbs.

    The results of the thesis are partly based on the conducted literature review, but also on interviews and observations regarding automated saffron cultivation and handling of saffron bulbs in Sweden. The results clearly indicate the requirements that are important for the system's functionality, safety, and user-friendliness, and based on this, a concept is developed where peeling is done first using the concept Borsta, followed by sieving using the concept Roller Belt Conveyor, and finally sorting using the concept The Roller. In verification tests, the final system is approved for the majority of the requirements. The results also present stainless steel, aluminum, PE, and PP as potentially suitable material choices.

    In the conclusions, it is stated that the most important requirements for the system are related to the machines' precision and their careful treatment of saffron bulbs. It is further concluded that these requirements are satisfactorily met by the final concept. Furthermore, it is found that this system is not dependent on complicated transport routes between the different machines, but instead, gravity can be utilized as a simpler solution to make the bulbs slide to the next machine. Finally, it is noted that requirements related to material selection must be further examined for specific applications as the prerequisites and resources for material testing are not available in this project.

    Keywords: Product development, saffron cultivation, automation, collaborative systems, indoor cultivation.

    Ladda ner fulltext (pdf)
    fulltext
  • 186.
    Lindgren, Isabelle
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Industriell marknadsföring och industriell ekonomi.
    The Art of Keeping a Contractor: A Study of How to Strengthen the Thread that Ties a Contractor to a Competence Agency2009Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    This thesis explores the fields of contracting and competence agencies. Itfocuses on the relationship between contractors and their agencies, and aims toidentify the expectations that contractors have on competence agencies and theactivities that can be undertaken by the agencies in order to improve andstrengthen the relation. A case study was made of a Danish competence agencyand of the contractors within its network. The qualitative part of the studyincluded interviews with five contractors and a questionnaire directed to theorganization. From the conclusions of the qualitative study and relevant theories,a set of hypotheses were formulated. The quantitative part consisted of a surveythat was sent out to the contractors in the network. The survey aimed to test thehypotheses and the results from the survey were analysed in Excel.The conclusions that were drawn from the outcome of the quantitative studywere that contractors join agencies because of the access to big companies thatare granted by agencies, because they do not have time to promote themselvesso they need someone to do it for them and because of the possibility to createnetworks and that contractors join more than one agency because they do notbelieve that one agency alone can supply them with full time occupation.Further on, it was also concluded that certain HRM as well as SHRM activitieshad a positive impact on the relationship, and that employer brandingstrengthened the bonds between the contractors and the competence agency.

    Ladda ner fulltext (pdf)
    FULLTEXT01
  • 187.
    Lindgren, Sofie
    et al.
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Logistik- och kvalitetsutveckling.
    Fjellström, Frida
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Logistik- och kvalitetsutveckling.
    Bättre leveransförmåga genom samordning i standardiserade vårdförlopp: Hur ska Diagnostikcentrum vara tillgängliga i bröstprocessen?2018Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    This report aims to investigate how Diagnostikcentrum should be available and coordinated with other care givers to achieve satisfactory delivery capability in cancer patient pathways.The availability refers to how Diagnostikcentrum should participate in the process. In whatway and with what recourses. The aim is to contribute to the process and its possibility ofgiving the patients care in time. Diagnostikcentrum performs diagnostic results and provides Region Östergötland with resources and competences in laboratory medicine and visual- and functional medicine. Diagnostics are the basis for investigating and giving the patient a correctdiagnosis. One area where Diagnostikcentrum is very much involved is in the cancer care.(Diagnostikcentrum, 2017)

    In Sweden, cancer have been increasing in recent years and the increase is expected to continue.This means there is a great need for a strategy for how cancer care should be conducted.(Cancerfonden, 2017) To improve the cancer care and shorten the lead times, cancer patientpathways have been introduced in Sweden. The purpose of a cancer patient pathway is that the patients should experience a well-organized, comprehensive and professional care without excessive waiting times (Cancercentrum, 2017). This report aims to investigate the cancerpatient pathway for breast cancer. In the process of breast cancer there are many different caregivers involved. A few from Diagnostikcentrum within different clinics. At present, thereis no knowledge if Diagnostikcentrum is being properly coordinated or involved in the correctway with this clinics and other caregivers.

    The research began with a literature review to gather research that were relevant to the study. For example, literature linked to process orientation, Supply Chain Management and delivery capacity. The literature covers the areas both from a traditional manufacturing perspective aswell as how these theories can be applied in health care. A flow mapping was carried out to gain an understanding of the care process for breast cancer. Based on this, an analysis of the process showed several areas of improvements such as sub-optimisation, bottlenecks and uncertainties.

    Delivery capacity for the breast process was defined based on literature and of the case study.The definition of delivery capacity was formulated as following. That 80 percent of the patientsgiven care in the cancer patient pathway for breast cancer should receive an investigation within 28 days. Based on that definition, it was later examined how well the process is performing today. The result was not positive and great opportunities for improvement exist. In present, only 41 percent of the patients receive an investigation for breast cancer in time. Based on the literature review, proposals were made for the coordination of the process.Such proposals included increased integration, collaboration and information sharing with the goal of achieving delivery capacity in the long term.

    Finally, suggestions that showed how Diagnostikcentrum can be available and contribute togreater coordination and compliance in the care process were made. The proposals imply that through adaptation to demand, increased flexibility and adaption to each other and the process the flow can be improved. Other suggestions include how to manage bottlenecks and iterations as well as dividing the lead time within the process, avoid sub-optimization through safer delivery times and finally improve measurement within the care process.

    Ladda ner fulltext (pdf)
    fulltext
  • 188.
    Lindkvist, Louise
    et al.
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Industriell Produktion. Linköpings universitet, Tekniska fakulteten.
    Sundin, Erik
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Industriell Produktion. Linköpings universitet, Tekniska fakulteten.
    A stepwise method towards products adapted for remanufacturing2016Ingår i: DS 84: Proceedings of the DESIGN 2016 14th International Design Conference / [ed] Marjanovic Dorian, Storga Mario, Pavkovic Neven, Bojcetic Nenad, Skec Stanko, The Design Society, 2016, Vol. 1-4, s. 321-330Konferensbidrag (Refereegranskat)
    Abstract [en]

    Remanufacturing is an important component of a resource-efficient manufacturing industry [see e.g. Rose and Ishii 1999; Steinhilper 1998; Sundin and Lee 2011]. By keeping components and their embodied material in use for a longer period of time, significant energy use and emissions to air and water (e.g. CO2 and SO2) can be avoided. According to Sundin and Lee [2011], environmental comparisons of remanufacturing versus new manufacturing and/or material recycling show environmental benefits for remanufacturing. This is due to alleviation of depletion of resources, reduction of global warming potential, and better chances to close the loop for safer handling of toxic materials [Sundin and Lee 2011]. In addition to its environmental benefits, remanufacturing provides opportunities for the creation of highly skilled jobs and economic growth.

     

    In order to make remanufacturing businesses more beneficial, product information should be accessible for the remanufacturing personnel and the products should be adapted for the remanufacturing process [Sundin and Bras 2005]. Although previous research identified information that could be fed back to the design phase from remanufacturing [e.g. Lindkvist and Sundin 2012] (see Table 1), such information is not often available in the design phase [Lindkvist and Sundin 2015]. Design for remanufacturing (DfRem) aims at facilitating the remanufacturing process so that e.g. disassembly, cleaning, reprocessing and reassembly are facilitated [Sundin and Bras 2005]. However, products are often not designed for remanufacture [Sundin and Bras 2005; Hatcher et al. 2011], although there do exist guidelines for design for remanufacturing [see e.g. Charter and Gray 2008, Sundin and Bras 2005].

     

    Successful integration of DfRem requires support on a strategic as well a tactical level, i.e. both what to do and how to do it [Yang et al. 2014]. Further, Hatcher et al. [2014] point out a gap in research regarding the operational factors influencing DfRem integration into the design process. In their findings, external factors such as customer demand and internal factors such as the OEM-remanufacturer relationship were identified. This paper addresses the combination of the strategic and tactical approaches, targeting the internal factors affecting DfRem integration into the design process. The proposed method is directed at companies that include both design and remanufacturing in their operations, and specifically supports integration of information from remanufacturing into the design process in order to better adapt products for remanufacturing. 

  • 189.
    Lindkvist, Louise
    et al.
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Industriell Produktion. Linköpings universitet, Tekniska fakulteten.
    Sundin, Erik
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Industriell Produktion. Linköpings universitet, Tekniska fakulteten.
    Analysing the service information transfer in the service development process at two automotive companies2016Ingår i: 23RD CIRP CONFERENCE ON LIFE CYCLE ENGINEERING, ELSEVIER SCIENCE BV , 2016, Vol. 48, s. 51-56Konferensbidrag (Refereegranskat)
    Abstract [en]

    As service renders an increasing share of companies revenues and affects a products environmental performance, the effectiveness of the services carried out is important. The aim of this paper is to analyse the service information transfer in the service development process at two automotive companies in order to explore its inefficiencies, and to promote steps to make it more efficient in the future. The work process during service development was mapped, focusing on the information transfer, including databases utilized and types of instructions produced. The studies show that some information provided to the service designers is insufficiently detailed and some databases are incompatible, causing rework in the service development process. Further, the information provided to service technicians comes in multiple formats, causing inefficiency in the service process, and feedback to the service designers is too time consuming. (C) 2016 The Authors. Published by Elsevier B.V.

    Ladda ner fulltext (pdf)
    fulltext
  • 190.
    Lindqvist, Olle
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluida och mekatroniska system.
    A Method of CFD-based System Identification for Standardized Co-Simulation2022Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    System simulations are a useful tool when analyzing complex systems. For example, simulations can be cheaper than physical testing of the actual system. Models canalso be created for systems that do not exist yet, that would be impossible to analyze experimentally. The models used in these system simulations require appropriate input data in order to give results with the required accuracy. Since each systemcan be made up of several different engineering domains, it can be difficult to inte-grate results from many different sources. For this thesis, the aim was to develop a methodology that allows CFD results to be integrated into a simulator using system identification and open-source standards.

    The system to be analyzed was a pipe connected to a heat exchanger and con-sumer of cooling power. The pipe model was to be able to calculate the pressure drop inside the pipe, based on the mass flow and specific enthalpy of the fluid. The fluid domain for the CFD simulations was divided into 5 smaller pipe sections in order to reduce the computational cost. The sections were meshed and verified, and a total of 100 steady-state flow cases were selected to give input and validation data for the system identification. The cases were run using the FEM-based Altair AcuSolve CFD solver. The extracted data from these cases was then imported to Altair romAI in order to create reduced-order models using neural networks. A model based on lookup-tables was also created. These models were then simulated as part of the cooling system and compared to the current model.

    The main result of the thesis is a proposed methodology for creating standardized ROMs based on CFD data. In addition, several important factors to consider before using the proposed methodology are presented. These include the intended use of the ROM, knowing the flow inside the system, what resources are available,and any potential licensing issues. The results also showed that steady-state data can be successfully used for system identification of steady-state models. The ROMs created using the method for this thesis gave results that were generally quite close to the currently used handbook equations. At lower Reynolds numbers, the CFD results were more unreliable, giving possible errors in the pressure drop calculatedby the ROMs at those flow cases.

    Ladda ner fulltext (pdf)
    fulltext
  • 191.
    Lingegård, Sofia
    et al.
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Industriell miljöteknik. Linköpings universitet, Tekniska fakulteten. Pontarius AB, Stockholm, Sweden.
    Lindahl, Mattias
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Industriell miljöteknik. Linköpings universitet, Tekniska fakulteten.
    Partnering as a Stepping Stone in the Transition to PSS for the Construction Industry2015Ingår i: Procedia CIRP, ISSN 2212-8271, E-ISSN 2212-8271, Vol. 30, s. 347-352Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The paper aims to explain and analyze how the construction industry can benefit from PSS, and how collaborative approaches such as partnering can be a stepping stone in this transition. The potential sub-optimization between construction and maintenance, as well as the necessity of availability in roads for example, make Product Service Systems a suitable approach for improvement. Adapted solutions though the iterative design approach, co-located actors, an active buyer and functioning information flows resulted in a successful project. Interviews conducted with the buyer, the contractor and the design consultant, as well as project documentation, were used to collect data.

    Ladda ner fulltext (pdf)
    fulltext
  • 192.
    Lingegård, Sofia
    et al.
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Industriell miljöteknik. Linköpings universitet, Tekniska fakulteten. Pontarius AB, Stockholm, Sweden.
    Lindahl, Mattias
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Industriell miljöteknik. Linköpings universitet, Tekniska fakulteten.
    Syberg, Andreas
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Industriell miljöteknik. Linköpings universitet, Tekniska fakulteten. Pontarius AB, Stockholm, Sweden.
    Life-cycle Cost Strategies for Harbors – A Case Study2015Ingår i: Procedia CIRP, ISSN 2212-8271, E-ISSN 2212-8271, Vol. 30, s. 317-322Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This paper discusses maintenance strategies for large technical systems with long life-cycles and critical availability needs. The use of sea freight is rapidly increasing, and thereby the use of container harbors as well. The case of Gothenburg harbor in Sweden is used to discuss appropriate construction and maintenance strategies focusing on availability. Investment costs, operational costs and societal costs are discussed along with environmental impact considerations. Different aspects and considerations affecting costs are also discussed, such as pay-back time and external uncertainties. The paper is based on an extensive literature review as well as interviews with harbor personnel.

    Ladda ner fulltext (pdf)
    fulltext
  • 193.
    Lingegård, Sofia
    et al.
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Industriell miljöteknik. Linköpings universitet, Tekniska högskolan.
    Sakao, Tomohiko
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Industriell miljöteknik. Linköpings universitet, Tekniska högskolan.
    Lindahl, Mattias
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Industriell miljöteknik. Linköpings universitet, Tekniska högskolan.
    Integrated Product Service Engineering - Factors Influencing Environmental Performance2012Ingår i: Systems Engineering: Practice and Theory / [ed] Boris Cogan, InTech , 2012, s. 147-164Kapitel i bok, del av antologi (Övrigt vetenskapligt)
    Abstract [en]

    This chapter endeavours to lead the scientific discussion regarding which IPSE factors are expected to, in theory, lower the environmental impact of a life cycle compared to a traditional product sales business. To do so, the IPSE concept is introduced, first with an emphasis on engineering processes rather than an object such as PSS. In the following sections, four aspects from theory will be discussed: product development, information asymmetry, economies of scale, and risk. These sections discuss how environmental impacts are influenced from a product life cycle perspective, and highlight crucial factors theoretically. They are followed by an overall discussion and an examination of some promising future work. The chapter provides the research community with a first theoretical cornerstone regarding environmental performance by IPSE. To practitioners, it will be an eye opener for how they engineer.

    Ladda ner fulltext (pdf)
    fulltext
  • 194.
    Lingegård, Sofia
    et al.
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Industriell miljöteknik. Linköpings universitet, Tekniska högskolan.
    Sakao, Tomohiko
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Industriell miljöteknik. Linköpings universitet, Tekniska högskolan.
    Lindahl, Mattias
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Industriell miljöteknik. Linköpings universitet, Tekniska högskolan.
    Integrated product service engineering: factors influencing environmental performance2011Ingår i: Design for Innovative Value Towards a Sustainable Society: Proceedings of EcoDesign 2011: 7th International Symposium on Environmentally Conscious Design and Inverse Manufacturing / [ed] M. Matsumoto, Y. Umeda, K. Masui, and S. Fukushige, Springer Netherlands, 2011, s. 386-391Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper aims to lead theoretical discussion regarding which IPSE (Integrated Product Service System) factors are expected to increase environmental performance of a life cycle compared to a traditional product sales business. Existing theories such as theory of product development, transaction cost theory and theory for risk management are used and the paper theoretically analyzes and identifies the following crucial characteristics; complexity of the product, uncertainty of offering, control of product operation, asymmetric information and scale of economy.

    Ladda ner fulltext (pdf)
    fulltext
  • 195.
    Lingegård, Sofia
    et al.
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Industriell miljöteknik. Linköpings universitet, Tekniska högskolan.
    Sakao, Tomohiko
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Industriell miljöteknik. Linköpings universitet, Tekniska högskolan.
    Lindahl, Mattias
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Industriell miljöteknik. Linköpings universitet, Tekniska högskolan.
    Theoretical Environmental Comparison of Integrated Product Service Offerings vs. Traditional Sales2011Ingår i: Systems Engineering / [ed] Boris Cogan, IN-TECH, 2011Kapitel i bok, del av antologi (Övrigt vetenskapligt)
    Abstract [en]

    The book "Systems Engineering: Practice and Theory" is a collection of articles written by developers and researches from all around the globe. Mostly they present methodologies for separate Systems Engineering processes; others consider issues of adjacent knowledge areas and sub-areas that significantly contribute to systems development, operation, and maintenance. Case studies include aircraft, spacecrafts, and space systems development, post-analysis of data collected during operation of large systems etc. Important issues related to "bottlenecks" of Systems Engineering, such as complexity, reliability, and safety of different kinds of systems, creation, operation and maintenance of services, system-human communication, and management tasks done during system projects are addressed in the collection. This book is for people who are interested in the modern state of the Systems Engineering knowledge area and for systems engineers involved in different activities of the area. Some articles may be a valuable source for university lecturers and students; most of case studies can be directly used in Systems Engineering courses as illustrative materials.

  • 196.
    Liu, Weihua
    et al.
    Tianjin Univ, Peoples R China.
    Hou, Jiahe
    Tianjin Univ, Peoples R China.
    Yan, Xiaoyu
    Tianjin Univ, Peoples R China.
    Tang, Ou
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Produktionsekonomi. Linköpings universitet, Tekniska fakulteten.
    Smart logistics transformation collaboration between manufacturers and logistics service providers: A supply chain contracting perspective2021Ingår i: Journal of Management Science and Engineering, ISSN 2096-2320, Vol. 6, nr 1, s. 25-52Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Intelligent transformation of manufacturers requires smart logistics transformation collaboration, which improves competitiveness. In this study, we construct a Stackelberg game model based on the mutual influence and restriction in the relationship between a manufacturer and a logistics service provider (LSP) undergoing smart logistics transformation. We investigate whether cost-sharing (CS) or revenue-sharing (RS) contracts can coordinate the supply chain and suggest a hybrid CS-RS contract to improve performance. We find that, compared with decentralized options, CS and RS contracts achieve a higher level of smart logistics transformation. While the coordination and effectiveness of CS contracts are superior to those of RS contracts, neither can fully coordinate the supply chain. The proposed hybrid CS-RS contract allows the manufacturer to share the LSPs costs before the transformation and its partial revenue after transformation, so that the LSP can reduce its service charge, thereby achieving full supply chain coordination. (c) 2021 China Science Publishing & Media Ltd. Publishing Services by Elsevier B.V. on behalf of KeAi Communications Co. Ltd.

    Ladda ner fulltext (pdf)
    fulltext
  • 197.
    Liu, Yang
    Department of Production, University of Vaasa, Vaasa, Finland.
    Sustainable competitive advantage in turbulent business environments2013Ingår i: International Journal of Production Research, ISSN 0020-7543, E-ISSN 1366-588X, Vol. 51, nr 10, s. 2821-2841Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The future competitiveness of manufacturing operations under dynamic and complex business environments relies on forward-thinking strategies. The objective of this paper is to identify and develop the operational competitiveness in a sustainable manner by implementing a unique sustainable competitive advantage (SCA) for managing dynamic business situations. This paper develops a theoretical approach to integrating the core factors which affect operational competitiveness performance, that is to say manufacturing strategy and transformational leadership with technology level, into conceptual analytical models to evaluate overall competitiveness, and utilises sense and respond (S&R) for dynamic decision-making to optimise resource allocations and adjust strategies in order to develop competitiveness potential in a sustainable manner. From the empirical research, the adjustments in manufacturing strategy and transformation leadership by implementing SCA through fast strategy with proposed models are found to be effective and successful in managing turbulent business environments such as the economic crisis. Such proactive operations are proposed as the unique SCA with empirical research carried out in a global context, which provides both theoretical significance and also practical benefit to conclude the experience of managing operations in turbulent business environments.

  • 198.
    Liu, Yang
    et al.
    Department of Production, University of Vaasa, Vaasa, Finland.
    Liang, Liting
    SC-Research, University of Vaasa, Vaasa, Finland.
    Evaluating and developing resource-based operations strategy for competitive advantage: an exploratory study of Finnish high-tech manufacturing industries2015Ingår i: International Journal of Production Research, ISSN 0020-7543, E-ISSN 1366-588X, Vol. 53, nr 4, s. 1019-1037Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Firms are struggling to achieve and maintain the competitive advantage in today’s turbulent business environment. How can we evaluate and (re)develop strategic initiatives that put into place operational capabilities to provide new sources of firm-level competitive advantage? This paper tries to explore the practical intersection of operations management and strategy from resource-based view by evaluating and developing the sustainability level of operational competitive advantage, that how well the resource-based strategy can support its operations. It develops a theoretical approach to integrate the core factors, which determine operational competitiveness performance – manufacturing strategy and its supporting resource allocation, into conceptual analytical models. The models utilise sense and respond (S&R) methodology for dynamic decision-making to detect and adjust resource allocation and in turn optimise the resource-based strategy in order to develop the operational competitive advantage in a sustainable manner. Eighteen case companies in Finnish high-tech manufacturing industries are selected for in-depth study and analysis with proposed models to conclude how the optimal adjustments of resource-based strategy by supporting its operations can lead to sustainable competitive advantage (SCA). Constantly optimising resource allocation aligning with resource-based operations strategy supported by the S&R idea of agile strategy implementations is proposed as the unique SCA.

  • 199.
    Liu, Yang
    et al.
    Department of Production, University of Vaasa, Vaasa, Finland.
    Takala, Josu
    Department of Production, University of Vaasa, Vaasa, Finland.
    Competitiveness development of Chinese manufacturing enterprises in global context for crisis management2010Ingår i: International Journal of Management and Enterprise Development, ISSN 1468-4330, E-ISSN 1741-8127, Vol. 9, nr 1, s. 87-115Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This paper connects previous research in global competitiveness analysis, taking the impact of global financial crisis into account, to evaluate how manufacturing companies are able to manage crisis by adjusting their manufacturing strategy and transformational leadership together with technology level to improve operational competitiveness performance. It develops a theoretical approach of integrating the core factors which influence the operational competitiveness performance, i.e. manufacturing strategy, and transformational leadership with technology level, into conceptual analytical models to evaluate overall competitiveness. The empirical studies are focused to case companies in the most dynamic market - China, especially large- and medium-sized manufacturing enterprises, and compare their operational performances in global context. The overall competitiveness of multiple cases are studied using the proposed analytical models to conclude the experience of crisis management, which can become a model for crisis management studies of companies globally as well as foreign companies in China.

  • 200.
    Ljusell, Ida
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Konstruktionsmaterial.
    Process characterisation of an additive manufacturing equipment: An analysis of the effect of electron beam powder bed fusion process parameters on the melt pool geometry and microstructure of Ti-6Al-4V2023Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Additive manufacturing (AM) are manufacturing methods where components are produced by adding material layer by layer which allows for a high freedom of design as well as little or no material waste compared to conventional manufacturing methods. Despite the many benefits of AM there are still problems concerning the quality of the produced material. In this project an AM equipment was tested by using different process parameters and comparing their effect on the printed material. An electron beam powder bed fusion equipment was used and with varying values for beam power, scanning speed and preheat temperature. Initial tests were done using Ti-6Al-4V plates with a Ti-6Al-4V powder then being used for a few selected process settings. The EB-PBF did not act as predicted with varying beam powers compared to input values. Melting tracks using powder also proved to be difficult due to, for example, the build plate moving from being overcharged by the electron beam and the difficulty to control the powder layers. The geometry of printed tracks on plates was analysed and values for melt pool width, depth and height was measured. Both width and depth for the most part have a linear increase with increased power and line energy density. Preheating temperature has a smaller effect on the width and depth but leads to more even tracks.

    Ladda ner fulltext (pdf)
    Process characterisation of anadditive manufacturing equipment
1234567 151 - 200 av 365
RefereraExporteraLänk till träfflistan
Permanent länk
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • oxford
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf