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Pettersson, K., Heybroek, K., Mattsson, P. & Krus, P. (2017). A novel hydromechanical hybrid motion system for construction machines. International Journal of Fluid Power, 18(1), 17-28
Open this publication in new window or tab >>A novel hydromechanical hybrid motion system for construction machines
2017 (English)In: International Journal of Fluid Power, ISSN 1439-9776, Vol. 18, no 1, p. 17-28Article in journal (Refereed) Published
Abstract [en]

This paper deals with a novel type of hybrid motion system for construction machines based on a common pressure rail shared between a hydromechanical power-split transmission and secondary controlled work hydraulics. A construction machine with driveline and work functions is a complex coupled motion system and the design of an effective hybrid system needs to take both subsystems into account. Studies on energy efficient hybrid systems for construction machines have hitherto principally focused on one subsystem at a time - work hydraulics or driveline. The paper demonstrates a use case with a specific transmission concept proposal for a medium-sized wheel loader. The system is modelled and simulated using an optimal energy management strategy based on dynamic programming. The results show the benefits of a throttle-free bidirectional link between the machine's subsystems and the energy storage, while taking advantage of the complex power flows of the power-split transmission.

Place, publisher, year, edition, pages
Abingdon, UK: Taylor & Francis, 2017
National Category
Mechanical Engineering
Identifiers
urn:nbn:se:liu:diva-142329 (URN)10.1080/14399776.2016.1210423 (DOI)
Available from: 2017-10-26 Created: 2017-10-26 Last updated: 2017-11-09Bibliographically approved
Hochwallner, M. & Krus, P. (2017). Hydraulic Infinite Linear Actuator -- The Ballistic Gait: Digital Hydro-Mechanical Motion. In: : . Paper presented at 15th Scandinavian International Conference on Fluid Power, SICFP’17, Linköping, Sweden, Juni 7-9, 2017. Linköping, Sweden
Open this publication in new window or tab >>Hydraulic Infinite Linear Actuator -- The Ballistic Gait: Digital Hydro-Mechanical Motion
2017 (English)Conference paper, Published paper (Refereed)
Abstract [en]

The Hydraulic Infinite Linear Actuator, HILA, has been presented in previous publications. The novel actuator consists of one, two or more double-acting cylinders witha common piston rod and hydraulically detachable pistons. In the basic gait, one cylinderalternatingly engages and drives the load while the other retracts. The HILA thus works in akind of rope-climbing motion. The concept also allows other gaits, i.e. patterns of motion.This contribution focuses on the ballistic gait, a pattern of motion where one cylinder engagesto give the load a push. The load then carries on with its motion by inertia, cylinders disen-gaged. The actuator thus realizes hydro-mechanical pulse-frequency modulation (PFM).This gait is energy efficient and able to recuperate energy.

Place, publisher, year, edition, pages
Linköping, Sweden: , 2017
Keywords
novel actuator, infinite linear motion, digital fluid power, digital hydromechanical motion, energy recuperation
National Category
Other Mechanical Engineering
Identifiers
urn:nbn:se:liu:diva-142416 (URN)
Conference
15th Scandinavian International Conference on Fluid Power, SICFP’17, Linköping, Sweden, Juni 7-9, 2017
Available from: 2017-10-30 Created: 2017-10-30 Last updated: 2017-11-23Bibliographically approved
Hochwallner, M. & Krus, P. (2017). Motion Control Concepts For The Hydraulic Infinite Linear Actuator. In: : . Paper presented at ASME 2016 9th FPNI Ph.D Symposium on Fluid Power -- FPNI2016. ASME Press, Article ID UNSP V001T01A017.
Open this publication in new window or tab >>Motion Control Concepts For The Hydraulic Infinite Linear Actuator
2017 (English)Conference paper, Published paper (Refereed)
Abstract [en]

This contribution presents the novel Hydraulic Infinite Linear Actuator (HILA). It focuses on the control of motion and is based on simulation and analysis. The novel actuator consists of two symmetric double acting cylinders with a common piston rod and hydraulically detachable pistons. Alternatingly one cylinder engages and drives the load while the other retracts, the HILA thus works in a kind of rope climbing motion. The purpose of this contribution is to study the motion control of the HILA and to mimic the behaviour of a conventional cylinder. The HILA has three degrees of freedom which are temporarily coupled compared with one in a conventional cylinder. Further, the HILA with the chosen hydraulic system has two continuous and two digital control inputs. The challenge to be tackled is to combine the short stroke back and forth motions of the cylinders into a continuous smooth motion of the whole actuator. Results from simulations and analyses show that the investigated concepts can keep the jerk within acceptable limits for many applications.

Place, publisher, year, edition, pages
ASME Press, 2017
Keywords
novel actuator, infinite linear stroke, cylinder, control
National Category
Mechanical Engineering
Identifiers
urn:nbn:se:liu:diva-136125 (URN)10.1115/FPNI2016-1523 (DOI)000398986900017 ()2-s2.0-85008258420 (Scopus ID)978-0-7918-5047-3 (ISBN)
Conference
ASME 2016 9th FPNI Ph.D Symposium on Fluid Power -- FPNI2016
Available from: 2017-03-28 Created: 2017-03-28 Last updated: 2017-05-05Bibliographically approved
Braun, R. & Krus, P. (2017). Parallel Implementations of the Complex-RF Algorithm. Engineering optimization (Print), 49(9), 1558-1572
Open this publication in new window or tab >>Parallel Implementations of the Complex-RF Algorithm
2017 (English)In: Engineering optimization (Print), ISSN 0305-215X, E-ISSN 1029-0273, Vol. 49, no 9, p. 1558-1572Article in journal (Refereed) Published
Abstract [en]

Even though direct-search optimization methods are more difficult to parallelize than population-based methods, there are many unexploited opportunities. Five methods for parallelizing the Complex-RF methods have been implemented and evaluated. Three methods are based on the unchanged original algorithm, while two require modifications. The methods have been tested on two test function and one real simulation model. An analysis of the algorithm has been performed. This provides a basis for parametrization of the parallel methods. Without changing the original algorithm, speed-up of 2.5-3 is achieved. With allowing modifications, a speed-up of up to 5 is obtained without significantly reducing the probability of finding the global minimum. Speed-up does not scale linear to the number of threads. When more threads are added, parallelization efficiency decreases. However, a comparison with a particle swarm method shows that Complex-RF performs better regardless of the number of threads, due to its fast convergence rate.

Place, publisher, year, edition, pages
Taylor & Francis, 2017
Keywords
Parallel optimization, direct-search, simplex, Complex-RF
National Category
Electrical Engineering, Electronic Engineering, Information Engineering Fluid Mechanics and Acoustics
Identifiers
urn:nbn:se:liu:diva-122751 (URN)10.1080/0305215X.2016.1260712 (DOI)000404810100006 ()
Note

The prevuous status of this article was Manuscript.

Available from: 2015-11-19 Created: 2015-11-19 Last updated: 2017-08-09Bibliographically approved
Krus, P., Ericson, L. & Sethson, M. (Eds.). (2017). Proceedings of 15:th Scandinavian International Conference on Fluid Power, June 7-9, 2017, Linköping, Sweden. Paper presented at 15:th Scandinavian International Conference on Fluid Power, June 7-9, 2017, Linköping, Sweden. Linköping: Linköping University Electronic Press
Open this publication in new window or tab >>Proceedings of 15:th Scandinavian International Conference on Fluid Power, June 7-9, 2017, Linköping, Sweden
2017 (English)Conference proceedings (editor) (Refereed)
Abstract [en]

SICFP2017

This is the proceedings of the 15th Scandinavian International Conference on Fluid Power held at Linköping University in Sweden on 7-9 June 2017. The theme of the conference was “Fluid Power in the Digital Age”. The contributions are well aligned with this theme, and are indeed reflecting the great developments. We are very grateful to the effort put in by the authors to produce such high quality papers, and also to those taking time to review papers to further enhance the quality. The contributions clearly shows that the fluid power industry, and academia, have both challenges as well as opportunities in keeping up with the evolving capabilities provided by the digitalization. It was with great joy to see old and new colleagues and friends attending our conference and the division of Fluid and mechatronic systems, at Linköping University. The conference is a bi-annual event, with alternating localization between Linköping in Sweden and Tampere in Finland. The process of hosting such an event is a great effort for our organization and I would like to thank all those involved in organizing this conference, and wish good luck with the next one to our Finnish colleagues. Thank you!

Prof. Petter Krus

Head of Division

Fluid and Mechatronic Systems

Review Process

Each author attending the conference days had the opportunity to select from three different ways of presenting their contribution. Firstly, a reviewed process with at least two international reviewers of each contribution. The process resulted in most cases with feedback from the reviewers with comments spanning everything between diagram legends to scientific methods. Some proposed papers where rejected upon recommendations from reviewers. Secondly contributions where also presented in industry sessions where the review process where internal only by the staff of the division. A third extended abstract presentation format where also presented during the conference.

This proceedings contain all presented contributions from the reviewed papers in the first section and thereafter the non-reviewed papers in second section. All reviewed papers are marked in the footer by the acceptance date.

Place, publisher, year, edition, pages
Linköping: Linköping University Electronic Press, 2017. p. 417
Series
Linköping Electronic Conference Proceedings, ISSN 1650-3686, E-ISSN 1650-3740 ; 144
National Category
Applied Mechanics
Identifiers
urn:nbn:se:liu:diva-143820 (URN)10.3384/ecp17144 (DOI)9789176853696 (ISBN)
Conference
15:th Scandinavian International Conference on Fluid Power, June 7-9, 2017, Linköping, Sweden
Available from: 2017-12-20 Created: 2017-12-20 Last updated: 2017-12-20Bibliographically approved
Axin, M., Eriksson, B. & Krus, P. (2016). A Flexible Working Hydraulic System for Mobile Machines. International Journal of Fluid Power, 17(2), 79-89
Open this publication in new window or tab >>A Flexible Working Hydraulic System for Mobile Machines
2016 (English)In: International Journal of Fluid Power, ISSN 1439-9776, Vol. 17, no 2, p. 79-89Article in journal (Other academic) Published
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.

Place, publisher, year, edition, pages
Taylor & Francis, 2016
Keywords
Mobile hydraulics, dynamics, energy efficiency, pump controller
National Category
Mechanical Engineering
Identifiers
urn:nbn:se:liu:diva-121068 (URN)10.1080/14399776.2016.1141635 (DOI)
Available from: 2015-09-04 Created: 2015-09-04 Last updated: 2017-12-04Bibliographically approved
Munjulury, R. C., Staack, I., Berry, P. & Krus, P. (2016). A knowledge-based integrated aircraft conceptual design framework. CEAS Aeronautical Journal, 7(1), 95-105
Open this publication in new window or tab >>A knowledge-based integrated aircraft conceptual design framework
2016 (English)In: CEAS Aeronautical Journal, ISSN 1869-5582, 1869-5590, Vol. 7, no 1, p. 95-105Article in journal (Refereed) Published
Abstract [en]

"The conceptual design is the early stage of aircraft design process where results are needed fast, both analytically and visually so that the design can be analyzed and eventually improved in the initial phases. Although there is no necessity for a CAD model from the very beginning of the design process, it can be an added advantage to have the model to get the impression and appearance. Furthermore, this means that a seamless transition into preliminary design is achieved since the CAD model can guardedly be made more detailed. For this purpose, knowledge-based aircraft conceptual design applications Tango (Matlab) and RAPID (CATIA) are being developed at Linköping University. Based on a parametric data definition in XML, this approach allows for a full 3D CAD integration. The one-database approach, also explored by many research organizations, enables the flexible and efficient integration of the different multidisciplinary processes during the whole conceptual design phase. This paper describes the knowledge-based design automated methodology of RAPID, data processing between RAPID and Tango and its application in the courses ‘‘Aircraft conceptual design’’ and ‘‘Aircraft project course’’ at Linköping University. A multifaceted user interface is developed to assist the whole design process."

Place, publisher, year, edition, pages
Springer, 2016
Keywords
Aircraft conceptual design, Knowledge based, XML database
National Category
Aerospace Engineering
Identifiers
urn:nbn:se:liu:diva-126689 (URN)10.1007/s13272-015-0174-z (DOI)
Projects
NFFP5/NFFP6
Available from: 2016-04-01 Created: 2016-04-01 Last updated: 2018-02-07
Baer, K., Ericson, L. & Krus, P. (2016). Aspects of Parameter Sensitivity for Series Hydraulic Hybrid Light-Weight Duty Vehicle Design. In: Proceedings of the 9th FPNI Ph.D. Symposium on Fluid Power (FPNI2016): . Paper presented at 9th FPNI Ph.D. Symposium on Fluid Power, Florianópolis, SC, Brazil, October 26–28, 2016. American Society of Mechanical Engineers, Article ID V001T01A041.
Open this publication in new window or tab >>Aspects of Parameter Sensitivity for Series Hydraulic Hybrid Light-Weight Duty Vehicle Design
2016 (English)In: Proceedings of the 9th FPNI Ph.D. Symposium on Fluid Power (FPNI2016), American Society of Mechanical Engineers , 2016, article id V001T01A041Conference paper, Published paper (Refereed)
Abstract [en]

Hybridization of a vehicle’s drivetrain can in principle help to improve its energy efficiency by allowing for recuperation of kinetic energy and modulating the engine’s load. How well this can be realized depends on appropriate sizing and control of the additional components. The system is typically designed sequentially, with the hardware setup preceding the development and tuning of advanced controller architectures. Taking an alternative approach, component sizing and controller tuning can be addressed simultaneously through simulation-based optimization.

The results of such optimizations, especially with standard algorithms with continuous design variable ranges, can however be difficult to realize, considering for example limitations in available components. Furthermore, drive-cycle based optimizations are prone to cycle-beating. This paper examines the results of such simulation-based optimization for a series hydraulic hybrid vehicle in terms of sensitivity to variations in design parameters, system parameters and drive cycle variations. Additional relevant aspects concerning the definition of the optimization problem are pointed out.

Place, publisher, year, edition, pages
American Society of Mechanical Engineers, 2016
Keywords
Weight (Mass), Automotive design, Cycles, Optimization, Control equipment, Simulation, Design, Hybrid electric vehicles, Hardware, Stress
National Category
Mechanical Engineering
Identifiers
urn:nbn:se:liu:diva-135737 (URN)10.1115/FPNI2016-1567 (DOI)978-0-7918-5047-3 (ISBN)
Conference
9th FPNI Ph.D. Symposium on Fluid Power, Florianópolis, SC, Brazil, October 26–28, 2016
Available from: 2017-03-17 Created: 2017-03-17 Last updated: 2018-03-09
Braun, R., Ericson, L. & Krus, P. (2016). Full Vehicle Simulation of Forwarder with Semi Active Suspension using Co-simulation. In: : . Paper presented at ASME/BATH 2015 Symposium on Fluid Power and Motion Control, October 12-14, 2015, Chicago, USA. ASME Press
Open this publication in new window or tab >>Full Vehicle Simulation of Forwarder with Semi Active Suspension using Co-simulation
2016 (English)Conference paper, Published paper (Refereed)
Abstract [en]

A major concern in the forest industry is impact on the soil caused by forest machines during harvesting. A six-wheel pendulum arm forwarder is being developed. The new forwarder aims at reducing soil damage by an even pressure distribution and smooth torque control and thereby also improving the working environment. The suspension contains pendulum arms on each wheel controlled by a hydraulic load sensing system in combination with accumulator.

A natural approach is to model each part of a system in the bestsuited software. In this case, the hydraulic system is modelled in the Hopsan simulation tool, while the vehicle mechanics is modelled in Adams. To understand the whole system it is necessary to simulate all subsystems together. An open standard for this is the Functional Mock-up Interface. This makes it possible to investigate the interaction between the hydraulic system and the multi-body mechanic model.

This paper describes how different simulation tools can be combined to support the development process. The technique is applied to the forwarder’s pendulum suspension. Controllers for height and soil force are optimized to minimize soil damage and maximize comfort for the operator.

Place, publisher, year, edition, pages
ASME Press, 2016
Keywords
System simulation, distributed solvers, parallelism, scheduling, transmission line element method
National Category
Electrical Engineering, Electronic Engineering, Information Engineering Fluid Mechanics and Acoustics
Identifiers
urn:nbn:se:liu:diva-122750 (URN)10.1115/FPMC2015-9588 (DOI)000373970500047 ()
Conference
ASME/BATH 2015 Symposium on Fluid Power and Motion Control, October 12-14, 2015, Chicago, USA
Available from: 2015-11-19 Created: 2015-11-19 Last updated: 2017-12-20Bibliographically approved
Dell'Amico, A. & Krus, P. (2016). Modelling and experimental validation of a nonlinear proportional solenoid pressure control valve. International Journal of Fluid Power, 17(2), 90-101
Open this publication in new window or tab >>Modelling and experimental validation of a nonlinear proportional solenoid pressure control valve
2016 (English)In: International Journal of Fluid Power, ISSN 1439-9776, Vol. 17, no 2, p. 90-101Article in journal (Refereed) Published
Abstract [en]

This paper investigates the static and dynamic behaviour of a pressure control valve with nonlinear negative characteristics. The pressure control valve has both reducing and relieving capability and is actuated by a solenoid. The static characteristics have been measured over the entire working range, covering the dynamic response of the solenoid, as well as the complete valve. A model is proposed that considers the flow as a mix of laminar and turbulent flow and flow forces with a flow angle that varies with the stroke of the spool. The model shows good agreement with measurements. The investigations show that the flow forces decrease with higher flow rates as a result of a flow angle that tends to go towards a vertical angle. This results in an increase in pressure with flow during pressure reducing mode. A linear analysis is also presented, explaining this as a negative spring constant in the low frequency range. Stability is, however, maintained.

Keywords
Nonlinear modelling, solenoid, pressure control valve, linear analysis
National Category
Fluid Mechanics and Acoustics
Identifiers
urn:nbn:se:liu:diva-130036 (URN)10.1080/14399776.2016.1141636 (DOI)
Available from: 2016-07-05 Created: 2016-07-05 Last updated: 2017-11-28
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-2315-0680

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