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  • 1.
    Axin, Mikael
    et al.
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluid och mekanisk systemteknik. Linköpings universitet, Tekniska högskolan.
    Braun, Robert
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluid och mekanisk systemteknik. Linköpings universitet, Tekniska högskolan.
    Dell'Amico, Alessandro
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluid och mekanisk systemteknik. Linköpings universitet, Tekniska högskolan.
    Eriksson, Björn
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluid och mekanisk systemteknik. Linköpings universitet, Tekniska högskolan.
    Nordin, Peter
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluid och mekanisk systemteknik. Linköpings universitet, Tekniska högskolan.
    Pettersson, Karl
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluid och mekanisk systemteknik. Linköpings universitet, Tekniska högskolan.
    Staack, Ingo
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluid och mekanisk systemteknik. Linköpings universitet, Tekniska högskolan.
    Krus, Petter
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluid och mekanisk systemteknik. Linköpings universitet, Tekniska högskolan.
    Next Generation Simulation Software using Transmission Line Elements2010Ingår i: Fluid Power and Motion Control / [ed] Dr D N Johnston and Professor A R Plummer, Centre for Power Transmission and Motion Control , 2010, s. 265-276Konferensbidrag (Refereegranskat)
    Abstract [en]

    A suitable method for simulating large complex dynamic systems is represented by distributed modelling using transmission line elements. The method is applicable to all physical systems, such as mechanical, electrical and pneumatics, but is particularly well suited to simulate systems where wave propagation is an important issue, for instance hydraulic systems. By using this method, components can be numerically isolated from each other, which provide highly robust numerical properties. It also enables the use of multi-core architecture since a system model can be composed by distributed simulations of subsystems on different processor cores.

    Technologies based on transmission lines has successfully been implemented in the HOPSAN simulation package, develop at Linköping University. Currently, the next generation of HOPSAN is developed using an object-oriented approach. The work is focused on compatibility, execution speed and real-time simulation in order to facilitate hardware-in-the-loop applications. This paper presents the work progress and some possible features in the new version of the HOPSAN simulation package.

  • 2.
    Axin, Mikael
    et al.
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluida och mekatroniska system. Linköpings universitet, Tekniska högskolan.
    Eriksson, Björn
    Parker Hannifin, Borås, Sweden.
    Krus, Petter
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluida och mekatroniska system. Linköpings universitet, Tekniska högskolan.
    A Flexible Working Hydraulic System for Mobile Machines2016Ingår i: International Journal of Fluid Power, ISSN 1439-9776, Vol. 17, nr 2, s. 79-89Artikel i tidskrift (Övrigt vetenskapligt)
    Abstract [en]

    This paper proposes a novel working hydraulic system architecture for mobile machines. Load sensing, flow control and open-centre are merged into a generalized system description. The proposed system is configurable and the operator can realize the characteristics of any of the standard systems without compromising energy efficiency. This can be done non-discretely on-the-fly. One electrically controlled variable displacement pump supplies the system and conventional closed-centre spool valves are used. The pump control strategies are explained in detail. Experimental results demonstrate one solution to the flow matching problem and the static and dynamic differences between different control modes.

  • 3.
    Axin, Mikael
    et al.
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluida och mekatroniska system. Linköpings universitet, Tekniska högskolan.
    Eriksson, Björn
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluida och mekatroniska system. Linköpings universitet, Tekniska högskolan.
    Krus, Petter
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluida och mekatroniska system. Linköpings universitet, Tekniska högskolan.
    A Hybrid of Pressure and Flow Control in Mobile Hydraulic Systems2014Ingår i: 9th InternationalFluid Power Conference (IFK). Vol. 1. Aachen, Germany, 24-26 March 2014 / [ed] Hubertus Murrenhoff, 2014, s. 190-201Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper presents a hybrid pump controller approach for mobile hydraulic systems, influenced by both pressure and flow. The controller is tuneable to be able to set the order of importance of the pressure and flow controller, respectively. It is thus possible to realize a load sensing system, a flow control system or a mix of the two. Using a low load pressure feedback gain and a high flow control gain, a system emerges with high energy efficiency, fast system response, high stability margins and no flow matching issues. In this paper, both theoretical studies and practical implementations demonstrate the capability of a hybrid pump control approach.

  • 4.
    Axin, Mikael
    et al.
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluida och mekatroniska system. Linköpings universitet, Tekniska högskolan.
    Eriksson, Björn
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluida och mekatroniska system. Linköpings universitet, Tekniska högskolan.
    Krus, Petter
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluida och mekatroniska system. Linköpings universitet, Tekniska högskolan.
    Energy Efficient Fluid Power System for Mobile Machines with Open-centre Characteristics2014Ingår i: 9th JFPS International Symposium on Fluid Power. Matsue, Japan, 28-31 October 2014, The Japan Fluid Power System Society , 2014, s. 452-459Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    This paper presents a flexible and energy efficient system solution which mimics the behaviour of an open-centre system. An electro-hydraulic variable displacement pump and closed-centre valves are used. Instead of having a flow in the open-centre gallery, that flow is calculated using a pressure sensor and a valve model. The variable pump is then controlled in order to only deliver the flow that would go to the actual loads. It is also possible for the operator to decide how much load dependency there should be. The extreme case is not having any load dependency at all, resulting in a system where the pump displacement setting is controlled according to the sum of all requested load flows. It is thus possible to realize a system design with open-centre characteristics, a flow control system or something in between. Each operator can thereby get their optimal control characteristic while having high energy efficiency.

  • 5.
    Axin, Mikael
    et al.
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluida och mekatroniska system. Linköpings universitet, Tekniska högskolan.
    Eriksson, Björn
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluida och mekatroniska system. Linköpings universitet, Tekniska högskolan.
    Krus, Petter
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluida och mekatroniska system. Linköpings universitet, Tekniska högskolan.
    Flow versus pressure control of pumps in mobile hydraulic systems2014Ingår i: Proceedings of the Institution of mechanical engineers. Part I, journal of systems and control engineering, ISSN 0959-6518, E-ISSN 2041-3041, Vol. 228, nr 4, s. 245-256Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This work studies an innovative working hydraulic system design for mobile applications, referred to as flow control. The fundamental difference compared to load-sensing systems is that the pump is controlled based on the operator’s command signals rather than feedback signals from the loads. This control approach enables higher energy efficiency since the pressure difference between pump and load is given by the system resistance rather than a prescribed pump pressure margin. Furthermore, load-sensing systems suffer from poor dynamic characteristics since the pump is operated in a closed-loop control mode. This might result in an oscillatory behaviour. Flow control systems have no stability issues attached to the load pressure feedback since there is none. This allows the pump to be designed to meet the response requirements without considering system stability. Pressure compensators are key components in flow control systems. This study addresses the flow matching problem which occurs when using traditional compensators in combination with a flow-controlled pump. Flow sharing pressure compensators solve this problem since the pump flow will be distributed between all active functions. Simulation results and measurements on a wheel loader application demonstrate the energy-saving potentials and the dynamic improvements for the flow control system.

  • 6.
    Axin, Mikael
    et al.
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluid och mekanisk systemteknik. Linköpings universitet, Tekniska högskolan.
    Eriksson, Björn
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluid och mekanisk systemteknik. Linköpings universitet, Tekniska högskolan.
    Palmberg, Jan-Ove
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluid och mekanisk systemteknik. Linköpings universitet, Tekniska högskolan.
    Energy Efficient Load Adapting System Without Load Sensing: Design and Evaluation2009Konferensbidrag (Refereegranskat)
    Abstract [en]

    In load sensing systems, the pump pressure is controlled in a closed loop control mode. In this paper, a system solution where the displacement of the pump is controlled directly from the operator's demand is studied. Both the stability and the response is thereby improved. It also implies a better energy efficiency since the pump pressure will be adapted according to the point of operation with no additional pressure margin needed. In some mobile applications, pressure compensation is required to avoid load interference. When using common pre compensators in a displacement controlled system, the pump and the valve will both control the flow. A better solution would be to control the flow by the pump and utilize the valve as a flow divider. This can be achieved by using flow sharing compensators. It also allows further energy savings since the maximum restriction area of the main spool at one of the loads can be utilized independent of the flow delivered by the pump. This paper addresses the problem with using common pre compensators in displacement controlled systems and analyses and compares both a traditional load sensing system and an open controlled pump solution with flow sharing compensators. Measurements on a wheel loader application equipped with the system presented in this paper shows a decreased energy consumption of 14 % for the working hydraulics compared to a load sensing system during a short loading cycle, provided that the pump is not saturated.

  • 7.
    Axin, Mikael
    et al.
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluida och mekatroniska system. Linköpings universitet, Tekniska högskolan.
    Eriksson, Björn
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluida och mekatroniska system. Linköpings universitet, Tekniska högskolan.
    Palmberg, Jan-Ove
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluida och mekatroniska system. Linköpings universitet, Tekniska högskolan.
    Krus, Petter
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluida och mekatroniska system. Linköpings universitet, Tekniska högskolan.
    Dynamic Analysis of Single Pump, Flow Controlled Mobile Systems2011Ingår i: The Twelfth Scandinavian International Conference on Fluid Power, SICFP'11: Volume 2 / [ed] Harri Sairiala & Kari T. Koskinen, 2011, s. 223-238Konferensbidrag (Refereegranskat)
    Abstract [en]

    Interest has increased in flow controlled systems in the field of mobile fluid power. The capital distinction between traditional load-sensing (LS) systems and flow controlled systems is that the pump is controlled based on the operator’s total flow demand rather than maintaining a certain pressure margin over the maximum load pressure. One of the main advantages of flow controlled systems is the absence of the feedback of the highest load pressure to the pump controller. In this paper, a dynamic analysis is performed where flow controlled and LS systems are compared. It is shown how instability can occur in LS systems due to the pump controller and proven that no such instability properties are present in flow controlled systems. A drawback with one type of flow controlled system is that the highest load dynamically will disturb the lighter loads. This paper shows a novel way to optimize the damping in such systems by controlling the opening position of the directional valve independently of the flow. The mentioned disturbance between the highest load to the others can thereby be reduced.

  • 8.
    Björn, Eriksson
    et al.
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluid och mekanisk systemteknik. Linköpings universitet, Tekniska högskolan.
    Rösth, Marcus
    MCD Parker Hannifin AB.
    Palmberg, Jan-Ove
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluid och mekanisk systemteknik. Linköpings universitet, Tekniska högskolan.
    Energy saving system utilizing LQ-technique design2009Ingår i: Proceedings of the Seventh International Conference on Fluid Power Transmission and Control: ICPF 2009 / [ed] Yongxiang, Lu and Qingfeng, Wang and Wei, Li and Bingfeng, Ju, Beijing: Beijing World Publishing Corporation , 2009, s. 224-229Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper deals with the control of individual metering systems. This paper deals with the control of an individual metering system that could be used for reducing metering losses by enabling recuperation and regeneration operation. A system that utilizes individual metering is more flexible than a conventional system since there are more control signals and thereby more outputs to control. Energy saving aspects is among the main reasons for the research on this kind of system, but there is also an opportunity of improvements of the dynamics compared to a conventional system. In this paper an approach with LQtechnique are presented for improvements of system dynamics. Since all states in the system can not be measured a state observer is also considered in the control design. These work present simulations, implementations in a real world forwarder application and results from verifying experiments.

  • 9.
    Braun, Robert
    et al.
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluida och mekatroniska system. Linköpings universitet, Tekniska högskolan.
    Nordin, Peter
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluida och mekatroniska system. Linköpings universitet, Tekniska högskolan.
    Eriksson, Björn
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluida och mekatroniska system. Linköpings universitet, Tekniska högskolan.
    Krus, Petter
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluida och mekatroniska system. Linköpings universitet, Tekniska högskolan.
    High Performance System Simulation Using Multiple Processor Cores2011Ingår i: The Twelfth Scandinavian International Conference on Fluid Power, SICFP'11 / [ed] Harri Sairiala & Kari T. Koskinen, 2011Konferensbidrag (Refereegranskat)
    Abstract [en]

    Future research and development will depend on high-speed simulations, especially for large and complex systems. Rapid prototyping, optimization and real-time simulations require  simulation tools that can take full advantage of  computer hardware.  Recent developments  in the computer market indicate  a change in focus from increasing the speed of processor cores towards increasing the number of cores in each processor. HOPSAN is a simulation tool for fluid power and mechatronics, developed at Linköping University. It  is based upon the transmission line  modeling  (TLM)  technique. This method is very suitable for taking advantage of multi-core  processors.  This paper presents  the  implementation  of multi-core support in the next generation of HOPSAN. The concept is to divide the  model  into equally sized  groups of  independent components,  to make it possible to  simulate  them  in separate threads. Reducing overhead costs and finding an effective sorting algorithm constitute  critical steps for maximizing the benefits.  Experimental results show  a significant reduction in simulation time. Improvement of algorithms in combination with a continuous increase in the number of processor cores can potentially  lead to further  increases  in simulation performance. 

  • 10.
    Ericson, Liselott
    et al.
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluida och mekatroniska system. Linköpings universitet, Tekniska högskolan.
    Eriksson, Björn
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluida och mekatroniska system. Linköpings universitet, Tekniska högskolan.
    Dell'Amico, Alessandro
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluida och mekatroniska system. Linköpings universitet, Tekniska högskolan.
    Krus, Petter
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluida och mekatroniska system. Linköpings universitet, Tekniska högskolan.
    An Electric Hydraulic Hybrid Light Vehicle with Energy Recovery2011Ingår i: 52nd National Conference on Fluid Power, Las, 2011, s. 741-749Konferensbidrag (Refereegranskat)
    Abstract [en]

    A three wheeled electric hydraulic hybrid vehicle with tiltingbody was built and tested at Linköping University as a partof a student project. The goal of the student project wasto design and fabricate an environmentally friendly vehicleto enter the Formula ATA Electric & Hybrid Italy 2009 competition.The design of the vehicle was based on the rulesand requirements of the competition. The vehicle was alsoprepared for a hydraulic recovery system which was laterimplemented on the vehicle. Hydraulic motor/pump unitsare used to brake and recover energy and to provide additionalboost during acceleration. The energy recovery storageis hydraulic gas accumulators, while the primary propulsionsystem is electrical with Li-Fe batteries. Gas accumulatorshave very high power density superior to electricalbatteries.In this paper, the design of the hydraulic recovery system isdescribed along with simulation and experimental results.The concept shows high potential and the tests show a20 % recovery of the kinetic energy by the hydraulic systemfor a given cycle.

  • 11.
    Eriksson, Björn
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluid och mekanisk systemteknik. Linköpings universitet, Tekniska högskolan.
    Control Strategy for Energy Efficient Fluid Power Actuators: Utilizing Individual Metering2007Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    This thesis presents a solution enabling lower losses in hydraulic actuator systems. A mobile fluid power system often contains several different actuators supplied with a single load sensing pump. One of the main advantages is the need of only one system pump. This makes the fluid power system compact and cost-effective.

    A hydraulic load often consists of two ports, e.g. motors and cylinders. Such loads have traditionally been controlled by a valve that controls these ports by one single control signal, namely the position of the spool in a control valve. In this kind of valve, the inlet (meter-in) and outlet (meter-out) orifices are mechanically connected. The mechanical connection makes the system robust and easy to control, at the same time as the system lacks flexibility. Some of the main drawbacks are

    The fixed relation between the inlet and outlet orifices in most applications produce too much throttling at the outlet orifice under most operating conditions. This makes the system inefficient.

    The flow directions are fixed for a given spool position; therefore, no energy recuperation and/or regeneration ability is available.

    In this thesis a novel system idea enabling, for example, recuperation and regeneration is presented. Recuperation is when flow is taken from a tank, pressurized by external loads, and then fed back into the pump line. Regeneration is when either cylinder chambers (or motor ports) are connected to the pump line. Only one system pump is needed. Pressure compensated (load independent), bidirectional, poppet valves are proposed and utilized.

    The novel system presented in this thesis needs only a position sensor on each compensator spool. This simple sensor is also suitable for identification of mode switches, e.g. between normal, differential and regenerative modes. Patent pending.

    The balance of where to put the functionality (hardware and/or software) makes it possible to manoeuvre the system with maintained speed control in the case of sensor failure. The main reason is that the novel system does not need pressure transducers for flow determination. Some features of the novel system:

    Mode switches The mode switches are accomplished without knowledge about the pressures in the system

    Throttle losses With the new system approach, choice of control and measure signals, the throttle losses at the control valves are reduced

    Smooth mode switches The system will switch to regenerative mode automatically in a smooth manner when possible

    Use energy stored in the loads The load, e.g. a cylinder, is able to be used as a motor when possible, enabling the system to recuperate overrun loads

    The system and its components are described together with the control algorithms that enable energy efficient operation. Measurements from a real application are also presented in the thesis.

    Delarbeten
    1. Study on Individual Pressure Control in Energy Efficient Cylinder Drives
    Öppna denna publikation i ny flik eller fönster >>Study on Individual Pressure Control in Energy Efficient Cylinder Drives
    2006 (Engelska)Ingår i: 4th FPNI-Ph.D. Symphosium, FPNI’06, Sarasota, United States, 13th–17th June, 2006, M. Ivantysynova (ed.), 2006, s. 77-99Konferensbidrag, Publicerat paper (Refereegranskat)
    Abstract [en]

    This paper deals with energy efficient mobile valves with cylinder loads. In recent years, the need for energy efficient fluid power systems has increased. The reason is the increasing price of oil as well as tougher environmental regulations. One way of achieving an energy efficient directional valve is to use individually controlled meter-in and meter-out orifices and transfer functionality from hardware to the software controller. This type of solution makes it possible to keep metering losses low. Energy recovery is also made possible since both speed and lowest cylinder chamber pressure can be controlled. The challenge in such a controller is to decouple the chamber pressures in the MIMO (multi-input-multi-output) hydraulic system into independent SISO (single-input-single-output) systems. In this paper, a decoupling based on a linear analysis of the physical system has been implemented and tested in a cylinder position control application. The controller is evaluated in terms of performance and robustness. In the near future, this project will continue with other approaches as well, as there are several interesting control approaches available.

     

    Nyckelord
    Fluid power, separate metering, decouped control
    Nationell ämneskategori
    Systemvetenskap, informationssystem och informatik
    Identifikatorer
    urn:nbn:se:liu:diva-12537 (URN)1-42430-499-7 (ISBN)
    Anmärkning
    Volume 1, No. 4Tillgänglig från: 2008-09-12 Skapad: 2008-09-12 Senast uppdaterad: 2018-01-12
    2. The Dynamic Properties of a Poppet Type Hydraulic Flow Amplifier
    Öppna denna publikation i ny flik eller fönster >>The Dynamic Properties of a Poppet Type Hydraulic Flow Amplifier
    2007 (Engelska)Ingår i: 10th Scandinavian International Conference on Fluid Power, SICFP´07 / [ed] J. Vilenius and K. T. Koskinen, Tampere, Finland: Tampere University of Technology , 2007, s. 161-178Konferensbidrag, Publicerat paper (Refereegranskat)
    Abstract [en]

    This paper examines the dynamic properties of a two-stage flow control valve of the "Valvistor" brand. There are several benefits to this: the valve ha a high closed loop bandwidth, the design allows big flow capacities etc. An attractive feature of this two-stage valve is that the pilot flow contributes to the total flow giving higher steady state flow efficiency. This paper presents an analythical model of this particular type of valve. A simplified model with relevant approximations is also presented. Measurements on the valve were made to validate the valve model. The paper also includes a further discussion about the pros and cons of the valve in open and closed loop applications.

    Ort, förlag, år, upplaga, sidor
    Tampere, Finland: Tampere University of Technology, 2007
    Nyckelord
    Fluid power, Valvistor, dynamic model
    Nationell ämneskategori
    Systemvetenskap, informationssystem och informatik
    Identifikatorer
    urn:nbn:se:liu:diva-12538 (URN)
    Konferens
    10th Scandinavian International Conference on Fluid Power, SICFP´07, 21st–23rd May, Tampere, Finland
    Tillgänglig från: 2008-09-12 Skapad: 2008-09-12 Senast uppdaterad: 2018-01-12
    3. A Novel Valve Concept Including the Valvistor Poppet Valve
    Öppna denna publikation i ny flik eller fönster >>A Novel Valve Concept Including the Valvistor Poppet Valve
    2007 (Engelska)Ingår i: The Tenth Scandinavian International Conference on Fluid Power / [ed] J. Vilenius and K. T. Koskinen, Tampere, Finland: Tampere University of Technology , 2007, s. 355-364Konferensbidrag, Publicerat paper (Refereegranskat)
    Abstract [en]

    These days, energy efficient mobile fluid power systems are of great interest. A mobile system containing several different cylinder drives supplied with a single load sensing pump (LS-pump) has a number of advantages as well as disadvantages. One fo the main advantages is the need of only one system pump. This makes the fluid power system compact and cost-effective. A challenge is to keep the hydraulic losses at a low level, especially losses at smaller loads. This paper introduces a fail-safe proportional valve element that is based on the Valvistor poppet valve. Due to the demands of flexibility the poppet valve is bi-directional. The valve has an innovative hydro-mechanic layout that makes it fail-safe, unwanted lowering loads, for example, never occur. The new valve includes simple sensors that are suitable for identificaiton of mode switches, e g between normal, differential and regenerative modes. It is also possible to manoevre the system with maintained velocity control in case of sensor failure. In a less complex system the concept has benefits as well. For example in systems where fail-safe bi-directional on/off valves are needed, then without mode sensing capabilities.

    Ort, förlag, år, upplaga, sidor
    Tampere, Finland: Tampere University of Technology, 2007
    Nyckelord
    Fluid power, poppet valve, Valvistor, bi-directional, fail-safe
    Nationell ämneskategori
    Systemvetenskap, informationssystem och informatik
    Identifikatorer
    urn:nbn:se:liu:diva-12539 (URN)
    Konferens
    10th Scandinavian International Conference on Fluid Power, SICFP´07, 21st–23rd May, Tampere, Finland
    Tillgänglig från: 2008-09-12 Skapad: 2008-09-12 Senast uppdaterad: 2018-01-12
  • 12.
    Eriksson, Björn
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluid och mekanisk systemteknik. Linköpings universitet, Tekniska högskolan.
    Mobile Fluid Power Systems Design: with a Focus on Energy Efficiency2010Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    This work deals with innovative energy efficient fluid power systems for mobile applications. The subjects taken up concern to what extent and how energy losses can be reduced in mobile working hydraulics systems. Various measures are available for increasing energy efficiency in these kinds of systems. Examples include:

    Flow controlled systems The pump controller is switched from a load sensing toa displacement controlled one. The displacement is controlled in an open loopfashion directly from the operator’s demand signals. This reduces energy consumptionat the same time as dynamic issues that are attached to LS systemscan be avoided.

    Individual metering valve systems Flexibility is increased by removing the mechanicalcoupling between the meter-in and meter-out orifices in directionalvalves. An overview of this kind of system is given in the thesis. A designproposal that has been implemented is also presented. Initial test results areshown. Patents for this particular system have been applied for.

    Displacement control Metering losses are reduced by removing the directional valves.One pump is used for each load in such systems. This hardware layout involvesconsiderable changes compared to conventional systems. Displacementcontrolled systems are not studied in this work.

    In mobile applications, overall efficiency is often poor and losses are substantial. The measures listed above can help improve this significantly in such applications. A flow dividing system can decrease energy consumption by about 10% and an individual metering system by about 20%. Losses in pump controlled systems are difficult to give a figure for; the losses are rather attached to the pumps and motors and not to the system layout. However, the losses for these systems are presumably even lower than for individual metering systems. The main focus in this work is on individual metering systems but questions about which components and so on are also treated. For example, the Valvistor valve concept has been studied as part of this work.

     

    Delarbeten
    1. Individual Metering Fluid Power Systems: Challenges and Opportunities
    Öppna denna publikation i ny flik eller fönster >>Individual Metering Fluid Power Systems: Challenges and Opportunities
    2011 (Engelska)Ingår i: Proceedings of the Institution of mechanical engineers. Part I, journal of systems and control engineering, ISSN 0959-6518, E-ISSN 2041-3041, Vol. 225, nr 12, s. 196-211Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    A review of recent and current research on individual metering fluid power systems is presented. An overview of different systems and their pros and cons is given. General challenges related to independent metering fluid power systems are discussed. The major choices in the design of these systems are the hardware layout and the control strategy. The evolution of existing independent metering fluid power systems from the 1970s until the present day is also presented.

    Ort, förlag, år, upplaga, sidor
    Professional Engineering Publishing, 2011
    Nationell ämneskategori
    Teknik och teknologier
    Identifikatorer
    urn:nbn:se:liu:diva-61360 (URN)000288805000002 ()
    Konferens
    Proceedings of the Sixth International Fluid Power Conference, IFK’08, March 31 - April 2, Dresden, Gemany
    Anmärkning

    DOI does not work: 10.1243/09596518JSCE1111

    Tillgänglig från: 2010-11-16 Skapad: 2010-11-16 Senast uppdaterad: 2018-03-12
    2. A High Energy Efficient Mobile Fluid Power System: Novel System Layout and Measurements
    Öppna denna publikation i ny flik eller fönster >>A High Energy Efficient Mobile Fluid Power System: Novel System Layout and Measurements
    2008 (Engelska)Konferensbidrag, Publicerat paper (Övrigt vetenskapligt)
    Abstract [en]

    This is one of the earliest publications of the proposed energy efficient individual metering system shown in chapter 5, section 5.3.3. This paper introduces the novel system design, which utilizes independent meter-in and meter-out valves. This system design has the potential to increase energy efficiency considerably in a system that consists of a pump  connected to more than one fluid power actuator. The system proposed here is not dependent on pressure transducers for either flow control or mode selection. The main difference between the work presented in this paper and earlier work is the control strategy. The output signal choices in the closed loops are new. Some functionality is kept in hardware to avoid  critical sensor dependency. The presented system uses pressure compensators to achieve desired flows.

    Nyckelord
    efficiency, energy saving, mobile system, fluid power
    Nationell ämneskategori
    Teknik och teknologier
    Identifikatorer
    urn:nbn:se:liu:diva-42262 (URN)62135 (Lokalt ID)62135 (Arkivnummer)62135 (OAI)
    Konferens
    Proceedings of the Sixth International Fluid Power Conference, IFK’08, March 31 - April 2, Dresden, Gemany
    Tillgänglig från: 2009-10-10 Skapad: 2009-10-10 Senast uppdaterad: 2015-08-31Bibliografiskt granskad
    3. Energy saving system utilizing LQ-technique design
    Öppna denna publikation i ny flik eller fönster >>Energy saving system utilizing LQ-technique design
    2009 (Engelska)Ingår i: Proceedings of the Seventh International Conference on Fluid Power Transmission and Control: ICPF 2009 / [ed] Yongxiang, Lu and Qingfeng, Wang and Wei, Li and Bingfeng, Ju, Beijing: Beijing World Publishing Corporation , 2009, s. 224-229Konferensbidrag, Publicerat paper (Refereegranskat)
    Abstract [en]

    This paper deals with the control of individual metering systems. This paper deals with the control of an individual metering system that could be used for reducing metering losses by enabling recuperation and regeneration operation. A system that utilizes individual metering is more flexible than a conventional system since there are more control signals and thereby more outputs to control. Energy saving aspects is among the main reasons for the research on this kind of system, but there is also an opportunity of improvements of the dynamics compared to a conventional system. In this paper an approach with LQtechnique are presented for improvements of system dynamics. Since all states in the system can not be measured a state observer is also considered in the control design. These work present simulations, implementations in a real world forwarder application and results from verifying experiments.

    Ort, förlag, år, upplaga, sidor
    Beijing: Beijing World Publishing Corporation, 2009
    Nyckelord
    fluid power, independent metering, energy savings, lq, flow amplifying poppet (fap), Valvistor, poppet valve
    Nationell ämneskategori
    Farkostteknik
    Identifikatorer
    urn:nbn:se:liu:diva-52028 (URN)978-775062-8213-0 (ISBN)
    Konferens
    7th International Conference on Fluid Power Transmission and Control
    Tillgänglig från: 2009-11-30 Skapad: 2009-11-30 Senast uppdaterad: 2015-08-31
    4. How to handle auxiliary functions in energy efficient, single pump, flow sharing mobile systems
    Öppna denna publikation i ny flik eller fönster >>How to handle auxiliary functions in energy efficient, single pump, flow sharing mobile systems
    2010 (Engelska)Ingår i: 7th International Fluid Power Conference Aachen: Efficiency Through Fluid Power, Workshop Proceedings, Vol. 1 / [ed] Hubertus Murrenhoff, Aachen: Apprimus Wissenschafts Verlag , 2010, Vol. 1, s. 65-78Konferensbidrag, Publicerat paper (Refereegranskat)
    Abstract [en]

    Interest has increasingly shifted from load-sensing (pressure controlled) systems to flow controlled systems. In this paper an interesting configuration that uses pre-compensated valves with flow sharing properties is studied. The fundamental difference between a traditional load sensing (LS) system and a flow controlled system is that the pump is controlled based on the operator’s total flow demand rather than maintaining a certain margin pressure over the maximum load pressure. One of the main advantages with flow controlled systems is the absence of the feedback of the highest load pressure to the pump. Flow controlled systems also present some challenges, one being how to handle auxiliary functions with unknown flow demands. Auxiliary functions are typically support legs, external power takeouts etc. This paper analyses one kind of flow controlled system and shows one way of dealing with auxiliary functions.

    Ort, förlag, år, upplaga, sidor
    Aachen: Apprimus Wissenschafts Verlag, 2010
    Nyckelord
    fluid power, load sensing, flow control, energy efficiency
    Nationell ämneskategori
    Teknik och teknologier
    Identifikatorer
    urn:nbn:se:liu:diva-58146 (URN)978-39-4056-590-7 (ISBN)
    Konferens
    The 7th International Fluid Power Conference, 22th- 24th March, Aachen, Germany
    Tillgänglig från: 2010-08-04 Skapad: 2010-08-04 Senast uppdaterad: 2015-08-31Bibliografiskt granskad
    5. A Novel Valve Concept Including the Valvistor Poppet Valve
    Öppna denna publikation i ny flik eller fönster >>A Novel Valve Concept Including the Valvistor Poppet Valve
    2008 (Engelska)Ingår i: Ventil : revija za fluidno tehniko in avtomatizacijo, ISSN 1318-7279, Vol. 14, nr 5, s. 433-442Artikel i tidskrift (Övrigt vetenskapligt) Published
    Abstract [en]

    These days, energy efficient mobile fluid power systems are of great interest. A mobile system containing several different cylinder drives supplied with a single load sensing pump (LS-pump) has a number of advantages as well as disadvantages. One of the main advantages is the need of only one system pump. This makes the fluid power system compact and cost-effective. A challenge is to keep the hydraulic losses at low level, especially losses at smaller loads. This paper introduces a fail-safe proportional valve element that is based on the Valvistor poppet valve. Due to the demands of flexibility the poppet valve is bi-directional. The valve has an innovative hydro-mechanical layout that makes it fail-safe, unwanted lowering loads, for example, never occur. The new valve includes simple sensors that are suitable for identification of mode switches, e g between normal, differential and regenerative modes. It is also possible to maneuver the system with maintainted velocity control in the case of sensor failure. In a less complex system the concept has benefits as well. For example in systems where fail-safe-bi-directional on/off valves are needed, then without mode sensing capabilities.

    Nyckelord
    fluid power, poppet valve, Valvistor, bi-directional, fail-safe
    Nationell ämneskategori
    Teknik och teknologier
    Identifikatorer
    urn:nbn:se:liu:diva-43301 (URN)73431 (Lokalt ID)73431 (Arkivnummer)73431 (OAI)
    Tillgänglig från: 2009-10-10 Skapad: 2009-10-10 Senast uppdaterad: 2015-08-31Bibliografiskt granskad
    6. The Dynamic Properties of a Poppet Type Hydraulic Flow Amplifier
    Öppna denna publikation i ny flik eller fönster >>The Dynamic Properties of a Poppet Type Hydraulic Flow Amplifier
    2007 (Engelska)Ingår i: 10th Scandinavian International Conference on Fluid Power, SICFP´07 / [ed] J. Vilenius and K. T. Koskinen, Tampere, Finland: Tampere University of Technology , 2007, s. 161-178Konferensbidrag, Publicerat paper (Refereegranskat)
    Abstract [en]

    This paper examines the dynamic properties of a two-stage flow control valve of the "Valvistor" brand. There are several benefits to this: the valve ha a high closed loop bandwidth, the design allows big flow capacities etc. An attractive feature of this two-stage valve is that the pilot flow contributes to the total flow giving higher steady state flow efficiency. This paper presents an analythical model of this particular type of valve. A simplified model with relevant approximations is also presented. Measurements on the valve were made to validate the valve model. The paper also includes a further discussion about the pros and cons of the valve in open and closed loop applications.

    Ort, förlag, år, upplaga, sidor
    Tampere, Finland: Tampere University of Technology, 2007
    Nyckelord
    Fluid power, Valvistor, dynamic model
    Nationell ämneskategori
    Systemvetenskap, informationssystem och informatik
    Identifikatorer
    urn:nbn:se:liu:diva-12538 (URN)
    Konferens
    10th Scandinavian International Conference on Fluid Power, SICFP´07, 21st–23rd May, Tampere, Finland
    Tillgänglig från: 2008-09-12 Skapad: 2008-09-12 Senast uppdaterad: 2018-01-12
    7. Hopsan NG, A C++ Implementation using the TLM Simulation Technique
    Öppna denna publikation i ny flik eller fönster >>Hopsan NG, A C++ Implementation using the TLM Simulation Technique
    2010 (Engelska)Ingår i: SIMS 2010 Proceedings, The 51st Conference on Simulation and Modelling, 14-15 October 2010 Oulu, Finland / [ed] sko Juuso, Oulu, Finland, 2010Konferensbidrag, Publicerat paper (Refereegranskat)
    Abstract [en]

    The Hopsan simulation package, used primarily for hydro-mechanical simulation, was first released in 1977. Modeling in Hopsan is based on a method using transmission line modeling, TLM. In TLM, component models are decoupled from each other through time delays. As components are decoupled and use distributed solvers, the simulation environment is suitable for distributed simulations. No numerical errors are introduced at simulation time when using TLM; all errors are related to modeling errors. This yields robust and fast simulations where the size of the time step does not have to be adjusted to achieve a numerically stable simulation. The distributive nature of TLM makes it convenient for use in multi-core approaches and high speed simulations. The latest version of Hopsan was released in August 2002, but now the next generation of this simulation package is being developed. This paper presents the development version of Hopsan NG and discusses some of its features and possible uses.

    Ort, förlag, år, upplaga, sidor
    Oulu, Finland: , 2010
    Nyckelord
    Hopsan, TLM, transmission lines, distributed modeling, distributed solvers
    Nationell ämneskategori
    Annan data- och informationsvetenskap
    Identifikatorer
    urn:nbn:se:liu:diva-60644 (URN)9789525183429 (ISBN)
    Konferens
    Conference of Scandinavian Simulation Society, sims’10, 14th–15th October, Oulu, Finland
    Projekt
    HiPO
    Tillgänglig från: 2010-10-21 Skapad: 2010-10-21 Senast uppdaterad: 2018-10-10Bibliografiskt granskad
  • 13.
    Eriksson, Björn
    et al.
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för konstruktions- och produktionsteknik, Fluid och mekanisk systemteknik.
    Andersson, Bo
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för konstruktions- och produktionsteknik, Fluid och mekanisk systemteknik.
    Palmberg, Jan-Ove
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för konstruktions- och produktionsteknik, Fluid och mekanisk systemteknik.
    The Dynamic Performance of a Pilot Stage in the Poppet Type Hydraulic Flow Amplifier2008Ingår i: The 51st NCFP Technical Conference,2008, Proceedings of the 51st NCFP Technical Conference: Omnipress , 2008, s. 659-Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper examines the dynamic properties of the pilot stage in a poppet type two-stage flow control valve of the -Valvistor- type. The particular valve studied is a screw-in Valvistor valve of NG16 size. There are several benefits to this valve type: it has a high closed loop bandwidth and the design allows big flow capacities. An attractive feature of this two-stage valve is that the pilot flow contributes to the total flow giving higher steady state flow efficiency. The dynamic characteristics of the main stage were discussed in an earlier paper. In this paper the aim is to study the influence of the pilot stage of the valve. The bandwidth of this type of valve is often unexpected low. Due to the high bandwidth of the Valvistor element the pilot dynamics is often dominating. In this paper it is shown by measurements the influence of different parts in the pilot valve that limits its bandwidth. Flow forces are used in this valve to compensate the pressure dependency in the flow. It is a common way of design in so called pressure compensated valves. It is discussed in the paper how this flow forces influences the dynamic properties of the pilot valve. The mentioned flow forces interact together with the mechanical spring in the pilot valve. Although the studied valve is just one of many variants of the Valvistor principle, we will investigate it closely due to the interest for this valve among other researchers. One important conclusion is that the inductance of the pilot solenoid is often limiting the bandwidth of the valve as a whole. 

  • 14.
    Eriksson, Björn
    et al.
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluid och mekanisk systemteknik. Linköpings universitet, Tekniska högskolan.
    Andersson, Bo
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluid och mekanisk systemteknik. Linköpings universitet, Tekniska högskolan.
    Palmberg, Jan-Ove
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluid och mekanisk systemteknik. Linköpings universitet, Tekniska högskolan.
    The Dynamic Properties of a Poppet Type Hydraulic Flow Amplifier2007Ingår i: 10th Scandinavian International Conference on Fluid Power, SICFP´07 / [ed] J. Vilenius and K. T. Koskinen, Tampere, Finland: Tampere University of Technology , 2007, s. 161-178Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper examines the dynamic properties of a two-stage flow control valve of the "Valvistor" brand. There are several benefits to this: the valve ha a high closed loop bandwidth, the design allows big flow capacities etc. An attractive feature of this two-stage valve is that the pilot flow contributes to the total flow giving higher steady state flow efficiency. This paper presents an analythical model of this particular type of valve. A simplified model with relevant approximations is also presented. Measurements on the valve were made to validate the valve model. The paper also includes a further discussion about the pros and cons of the valve in open and closed loop applications.

  • 15.
    Eriksson, Björn
    et al.
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för konstruktions- och produktionsteknik, Fluid och mekanisk systemteknik.
    Larsson, Jonas
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för konstruktions- och produktionsteknik, Fluid och mekanisk systemteknik.
    Palmberg, Jan-Ove
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för konstruktions- och produktionsteknik, Fluid och mekanisk systemteknik.
    A Novel Valve Concept Including the Valvistor Poppet Valve2008Ingår i: Ventil : revija za fluidno tehniko in avtomatizacijo, ISSN 1318-7279, Vol. 14, nr 5, s. 433-442Artikel i tidskrift (Övrigt vetenskapligt)
    Abstract [en]

    These days, energy efficient mobile fluid power systems are of great interest. A mobile system containing several different cylinder drives supplied with a single load sensing pump (LS-pump) has a number of advantages as well as disadvantages. One of the main advantages is the need of only one system pump. This makes the fluid power system compact and cost-effective. A challenge is to keep the hydraulic losses at low level, especially losses at smaller loads. This paper introduces a fail-safe proportional valve element that is based on the Valvistor poppet valve. Due to the demands of flexibility the poppet valve is bi-directional. The valve has an innovative hydro-mechanical layout that makes it fail-safe, unwanted lowering loads, for example, never occur. The new valve includes simple sensors that are suitable for identification of mode switches, e g between normal, differential and regenerative modes. It is also possible to maneuver the system with maintainted velocity control in the case of sensor failure. In a less complex system the concept has benefits as well. For example in systems where fail-safe-bi-directional on/off valves are needed, then without mode sensing capabilities.

  • 16.
    Eriksson, Björn
    et al.
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluid och mekanisk systemteknik. Linköpings universitet, Tekniska högskolan.
    Larsson, Jonas
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling. Linköpings universitet, Tekniska högskolan.
    Palmberg, Jan-Ove
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluid och mekanisk systemteknik. Linköpings universitet, Tekniska högskolan.
    A Novel Valve Concept Including the Valvistor Poppet Valve2007Ingår i: The Tenth Scandinavian International Conference on Fluid Power / [ed] J. Vilenius and K. T. Koskinen, Tampere, Finland: Tampere University of Technology , 2007, s. 355-364Konferensbidrag (Refereegranskat)
    Abstract [en]

    These days, energy efficient mobile fluid power systems are of great interest. A mobile system containing several different cylinder drives supplied with a single load sensing pump (LS-pump) has a number of advantages as well as disadvantages. One fo the main advantages is the need of only one system pump. This makes the fluid power system compact and cost-effective. A challenge is to keep the hydraulic losses at a low level, especially losses at smaller loads. This paper introduces a fail-safe proportional valve element that is based on the Valvistor poppet valve. Due to the demands of flexibility the poppet valve is bi-directional. The valve has an innovative hydro-mechanic layout that makes it fail-safe, unwanted lowering loads, for example, never occur. The new valve includes simple sensors that are suitable for identificaiton of mode switches, e g between normal, differential and regenerative modes. It is also possible to manoevre the system with maintained velocity control in case of sensor failure. In a less complex system the concept has benefits as well. For example in systems where fail-safe bi-directional on/off valves are needed, then without mode sensing capabilities.

  • 17.
    Eriksson, Björn
    et al.
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluid och mekanisk systemteknik. Linköpings universitet, Tekniska högskolan.
    Larsson, Jonas
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling. Linköpings universitet, Tekniska högskolan.
    Palmberg, Jan-Ove
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluid och mekanisk systemteknik. Linköpings universitet, Tekniska högskolan.
    Study on Individual Pressure Control in Energy Efficient Cylinder Drives2006Ingår i: 4th FPNI-Ph.D. Symphosium, FPNI’06, Sarasota, United States, 13th–17th June, 2006, M. Ivantysynova (ed.), 2006, s. 77-99Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper deals with energy efficient mobile valves with cylinder loads. In recent years, the need for energy efficient fluid power systems has increased. The reason is the increasing price of oil as well as tougher environmental regulations. One way of achieving an energy efficient directional valve is to use individually controlled meter-in and meter-out orifices and transfer functionality from hardware to the software controller. This type of solution makes it possible to keep metering losses low. Energy recovery is also made possible since both speed and lowest cylinder chamber pressure can be controlled. The challenge in such a controller is to decouple the chamber pressures in the MIMO (multi-input-multi-output) hydraulic system into independent SISO (single-input-single-output) systems. In this paper, a decoupling based on a linear analysis of the physical system has been implemented and tested in a cylinder position control application. The controller is evaluated in terms of performance and robustness. In the near future, this project will continue with other approaches as well, as there are several interesting control approaches available.

     

  • 18.
    Eriksson, Björn
    et al.
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluid och mekanisk systemteknik. Linköpings universitet, Tekniska högskolan.
    Nordin, Peter
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluid och mekanisk systemteknik. Linköpings universitet, Tekniska högskolan.
    Krus, Petter
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluid och mekanisk systemteknik. Linköpings universitet, Tekniska högskolan.
    Hopsan NG, A C++ Implementation using the TLM Simulation Technique2010Ingår i: SIMS 2010 Proceedings, The 51st Conference on Simulation and Modelling, 14-15 October 2010 Oulu, Finland / [ed] sko Juuso, Oulu, Finland, 2010Konferensbidrag (Refereegranskat)
    Abstract [en]

    The Hopsan simulation package, used primarily for hydro-mechanical simulation, was first released in 1977. Modeling in Hopsan is based on a method using transmission line modeling, TLM. In TLM, component models are decoupled from each other through time delays. As components are decoupled and use distributed solvers, the simulation environment is suitable for distributed simulations. No numerical errors are introduced at simulation time when using TLM; all errors are related to modeling errors. This yields robust and fast simulations where the size of the time step does not have to be adjusted to achieve a numerically stable simulation. The distributive nature of TLM makes it convenient for use in multi-core approaches and high speed simulations. The latest version of Hopsan was released in August 2002, but now the next generation of this simulation package is being developed. This paper presents the development version of Hopsan NG and discusses some of its features and possible uses.

  • 19.
    Eriksson, Björn
    et al.
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluid och mekanisk systemteknik. Linköpings universitet, Tekniska högskolan.
    Palmberg, Jan-Ove
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluid och mekanisk systemteknik. Linköpings universitet, Tekniska högskolan.
    How to handle auxiliary functions in energy efficient, single pump, flow sharing mobile systems2010Ingår i: 7th International Fluid Power Conference Aachen: Efficiency Through Fluid Power, Workshop Proceedings, Vol. 1 / [ed] Hubertus Murrenhoff, Aachen: Apprimus Wissenschafts Verlag , 2010, Vol. 1, s. 65-78Konferensbidrag (Refereegranskat)
    Abstract [en]

    Interest has increasingly shifted from load-sensing (pressure controlled) systems to flow controlled systems. In this paper an interesting configuration that uses pre-compensated valves with flow sharing properties is studied. The fundamental difference between a traditional load sensing (LS) system and a flow controlled system is that the pump is controlled based on the operator’s total flow demand rather than maintaining a certain margin pressure over the maximum load pressure. One of the main advantages with flow controlled systems is the absence of the feedback of the highest load pressure to the pump. Flow controlled systems also present some challenges, one being how to handle auxiliary functions with unknown flow demands. Auxiliary functions are typically support legs, external power takeouts etc. This paper analyses one kind of flow controlled system and shows one way of dealing with auxiliary functions.

  • 20.
    Eriksson, Björn
    et al.
    Linköpings universitet, Institutionen för konstruktions- och produktionsteknik, Fluid och mekanisk systemteknik. Linköpings universitet, Tekniska högskolan.
    Palmberg, Jan-Ove
    Linköpings universitet, Institutionen för konstruktions- och produktionsteknik, Fluid och mekanisk systemteknik. Linköpings universitet, Tekniska högskolan.
    Individual Metering Fluid Power Systems: Challenges and Opportunities2011Ingår i: Proceedings of the Institution of mechanical engineers. Part I, journal of systems and control engineering, ISSN 0959-6518, E-ISSN 2041-3041, Vol. 225, nr 12, s. 196-211Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A review of recent and current research on individual metering fluid power systems is presented. An overview of different systems and their pros and cons is given. General challenges related to independent metering fluid power systems are discussed. The major choices in the design of these systems are the hardware layout and the control strategy. The evolution of existing independent metering fluid power systems from the 1970s until the present day is also presented.

  • 21.
    Eriksson, Björn
    et al.
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för konstruktions- och produktionsteknik, Fluid och mekanisk systemteknik.
    Palmberg, Jan-Ove
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för konstruktions- och produktionsteknik, Fluid och mekanisk systemteknik.
    Modellering och design av Valvistorn2007Ingår i: Hydraulikdagar 07,2007, Linköping: Linköpings universitet , 2007Konferensbidrag (Övrigt vetenskapligt)
    Abstract [sv]

     Detta paper presenterar en modellering av den kända Valvistorventilen samt en ny utvidgning av denna ventil som ger den proportionalegenskaper i två flödesriktningar på ett fail-safe sätt.

  • 22.
    Eriksson, Björn
    et al.
    Linköpings universitet, Institutionen för konstruktions- och produktionsteknik, Fluid och mekanisk systemteknik. Linköpings universitet, Tekniska högskolan.
    Rösth, Marcus
    MCD Parker Hannifin AB.
    Palmberg, Jan-Ove
    Linköpings universitet, Institutionen för konstruktions- och produktionsteknik, Fluid och mekanisk systemteknik. Linköpings universitet, Tekniska högskolan.
    A High Energy Efficient Mobile Fluid Power System: Novel System Layout and Measurements2008Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    This is one of the earliest publications of the proposed energy efficient individual metering system shown in chapter 5, section 5.3.3. This paper introduces the novel system design, which utilizes independent meter-in and meter-out valves. This system design has the potential to increase energy efficiency considerably in a system that consists of a pump  connected to more than one fluid power actuator. The system proposed here is not dependent on pressure transducers for either flow control or mode selection. The main difference between the work presented in this paper and earlier work is the control strategy. The output signal choices in the closed loops are new. Some functionality is kept in hardware to avoid  critical sensor dependency. The presented system uses pressure compensators to achieve desired flows.

  • 23.
    Eriksson, Björn
    et al.
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluid och mekanisk systemteknik. Linköpings universitet, Tekniska högskolan.
    Rösth, Marcus
    MCD Parker Hannifin AB.
    Palmberg, Jan-Ove
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluid och mekanisk systemteknik. Linköpings universitet, Tekniska högskolan.
    An LQ-Control Approach for Independent Metering Systems2009Ingår i: 11th Scandinavian International Conference on Fluid Power, SICFP'09, Linköping, Sweden, 2nd-4th June, Linköping, 2009Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper deals with the control of an individual metering fluid power system. There are a number of reasons to use individual metering technology, one is flexibility. In traditional valves there is a mechanical connection between the meter-in orifice and the meter-out orifice. By control this orifices individually one valve can be used in different applications without hard- ware modifications. Instead of change spool the software is changed. Since there are more control signals and thereby more outputs to control there is also an opportunity of improve- ments of the dynamics compared to a conventional system. In this paper an approach with LQ-technique is presented for improvements of system dynamics. Since all states in the sys- tem can not be measured a state observer is also considered in the control design. These work present simulations, implementations in a real world forwarder application and results from ve- rifying experiments.

  • 24.
    Krus, Petter
    et al.
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluida och mekatroniska system. Linköpings universitet, Tekniska högskolan.
    Braun, Robert
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluida och mekatroniska system. Linköpings universitet, Tekniska högskolan.
    Nordin, Peter
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluida och mekatroniska system. Linköpings universitet, Tekniska högskolan.
    Eriksson, Björn
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Fluida och mekatroniska system. Linköpings universitet, Tekniska högskolan.
    Aircraft System Simulation for Preliminary Design2012Ingår i: ICAS 2012 CD-ROM PROCEEDINGS / [ed] Professor I Grant, Optimage Ltd , 2012, s. Art.nr. ICAS2012-1.9.3-Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    Developments in computational hardware and simulation software have come to a point where it is possible to use whole mission simulation in a framework for conceptual/preliminary design. This paper is about the implementation of full system simulation software for conceptual/preliminary aircraft design. It is based on the new Hopsan NG simulation package, developed at the Linköping University. The Hopsan NG software is implemented in C++. Hopsan NG is the first simulation software that has support for multi-core simulation for high speed simulation of multi domain systems.

    In this paper this is demonstrated on a flight simulation model with subsystems, such as control surface actuators.

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