Gerhard Ruth
Department for Product Development, University of Leoben, Leoben, Austria
Emil Zæv
Faculty of Mechanical Engineering, Ss.Cyril and Methodius University in Skopje, Skopje, Macedonia
Ladda ner artikel
http://dx.doi.org/10.3384/ecp1392a25Ingår i: 13th Scandinavian International Conference on Fluid Power; June 3-5; 2013; Linköping; Sweden
Linköping Electronic Conference Proceedings 92:25, s. 251-259
Publicerad: 2013-09-09
ISBN: 978-91-7519-572-8
ISSN: 1650-3686 (tryckt), 1650-3740 (online)
Hydraulic servo system driven with separate meter-in and meter-out valves provide more flexibility with respect to energy efficiency and dynamic properties. In the current problem the operation of such a configuration involves to keep a desired position constant; while an external load force is applied. The position control cannot compensate for fast load fluctuations beyond a certain frequency limit. For this case it can be desired to adjust the static pressures in the cylinder chambers to defined values. The paper describes how to influence this pressures giving weights to the control signals for both moving directions for each valve. With the help of a simulation model the design results are verified. Higher pressure levels decrease the danger of cavitation and inhibit lowering the bulk modulus of the oil volume. The asymmetric control of the valves even lead to better energy efficiency during position control.
[1] H E Merritt. Hydraulic Control Systems. John Wileys and Sons; Cincinnati; Ohio; 1967. ISBN 0-471-59617- 5.
[2] W. J. Thayer. Transfer functions for moog servovalves. In Technical Bulletin 103. Moog Inc.; East Aurora; NY; 1965.
[3] R. Poley. Dsp control of electro-hydraulic servo actuators. In Application Report SPRAA76. Texas Instruments; 2005.
[4] M. Jelali and A. Kroll. Hydraulic Servo-systems: Modeling; Identification and Control. Springer; London; 2003.
[5] C.C. DeBoer and B. Yao. Energy-efficient motion control of a digital hydraulic joint actuator. In Proceedings of IMECE’01 2001 ASME International Mechanical Engineering Congress and Exposition; pages DSC– 2B–3; New York; USA; 2001. Japan Fluid Power System Society.
[6] K.A. Tabor. Velocity based method of controlling an electrohydraulic proportional control valve. United States patent application No. 20040055453; 2004.
[7] B.K. Nielsen. Controller Development for a Separate Meter-in Separate Meter-out Fluid Power Valve for Mobile Applications. PhD thesis; Institute of Energy Technology; Aalborg University; Aalborg; Denmark; 2005.
[8] B. Eriksson. Mobile Fluid Power Systems Design with a Focus on Energy Efficiency. PhD thesis; Institute of Technology; Linköping University; Linköping; Sweden; 2010.
[9] A.H. Hansen; H.C. Pedersen; T.O. Andersen; and L. Wachmann. Design of energy efficient smismo-els control strategies. In 2011 International Conference on Fluid Power and Mechatronics (FPM); pages 522–527; Aug. 2011.
[10] H.C. Pedersen; T.O. Andersen; Hansen R.H.; and S. Stubkier. Investigation of separate meter-in separate meter-out control strategies for systems with over centre valves. In Proc. of the ASME Symposium on Fluid Power and Motion Control; FPMC 2010. American Society of Mechanical Engineers; 2010.
[11] B. Eggers; R. Rahmfeld; andM. Ivantysynova. An energetic comparison between valveless and valve controlled active vibration damping for off-road vehicles. In Proceedings of the 6th JFPS International Symposium on Fluid Power; pages 276–283; Tsukuba; Japan; 2005. Japan Fluid Power System Society.
[12] E. Zaev. ’Hardware-In-The-Loop’ for real-time simulation of complex mechanical systems and their control. PhD thesis; Faculty of Mechanical Engineering; SS. Cyril and Methodius University; Skopje; Macedonia; 2013.
[13] A. Shenouda. Quasi-Static Hydraulic Control Systems and Energy Savings Potential Using Independent Metering Four-Valve Assembly. PhD thesis;Woodruff School of Mechanical Engineering; Georgia Institute of Technology; Georgia; 2006.
[14] G. Rath. Dynamics of high precision position controlled hydraulic cylinder subjected to elastic load. In K.T.
Koskinen and M. Vilenius; editors; The Eighth Scandinavian International Conference on Fluid Power; Proceedings; pages 383–396; Tampere; Finland; 2003.
[15] W. Backé and H. Murrenhof. Grundlagen der ölhydraulik. Lecture notes; RWTH Aachen; Germany; 1994.
[16] R. Forsberg. Cut profile accuracy of roadheaders: Influence of different components and measures for improvements. Master’s thesis; KTH Machine Design; Stockholm; Sweden; 2005.
[17] G.F. Franklin; M.L. Workman; and D. Powell. Digital Control of Dynamic Systems. Addison-Wesley Longman Publishing Co.; Inc.; Boston; MA; USA; 3rd edition; 1997.
[18] K. Heybroek. Saving Energy in Construction Machinery using Displacement Control Hydraulics; Concept Realization and Validation. PhD thesis; Institute of Technology; Linköping University; Linköping; Sweden; 2008.
[19] P. Krus. On Load Sensing Fluid Power Systems; With Special Reference to Dynamic Properties and Control Aspects. PhD thesis; Department of Mechanical Engineering; Linköping University; Linköping; Sweden; 1988.
[20] T. Shang. Improving Performance of an Energy Efficient Hydraulic Circuit. PhD thesis; Department of Mechanical Engineering; University of Saskatchewan; Saskatoon; Canada; 2004.
[21] M. Linjama and M. Vilenius. Energy-efficient motion control of a digital hydraulic joint actuator. In Proceedings of the 6th JFPS International Symposium on Fluid Power; pages 640–645; Tsukuba; Japan; 2005. Japan Fluid Power System Society.
[22] Y. Jinghong; C. Zhaoneng; and L. Yuanzhang. The variation of oil effective bulk modulus with pressure in hydraulic systems. Journal of Dynamic Systems; Measurement; and Control; 116(1):146–150; 1994.
