ESTABLISHING OPERATING POINTS FOR A LINEARIZED MODEL OF A LOAD SENSING SYSTEM

Authors

  • Duqiang Wu Department of Mechanical Engineering, University of Saskatchewan 57 Campus Drive, Saskatoon, Saskatchewan, Canada, S7N 5A9
  • Richard Burton Department of Mechanical Engineering, University of Saskatchewan 57 Campus Drive, Saskatoon, Saskatchewan, Canada, S7N 5A9
  • Greg Schoenau Department of Mechanical Engineering, University of Saskatchewan 57 Campus Drive, Saskatoon, Saskatchewan, Canada, S7N 5A9
  • Doug Bitner Department of Mechanical Engineering, University of Saskatchewan 57 Campus Drive, Saskatoon, Saskatchewan, Canada, S7N 5A9

Keywords:

load sensing, steady state operating point, transition point, pressure regulator, pressure control pump

Abstract

A load sensing system is one in which the pump flow is adjusted to keep pressure across an orifice constant and in-dependent of any variation in the load pressure. This ensures that the pressure losses across the orifice are kept to a min-imum which increases efficiency substantially. Because the system is closed loop, stability can become a problem. To establish stability bounds, linearized analysis is often employed. However, to do this, operating points of all linearized parameters and coefficients must be established as a function of certain parameters such as load pressure. This can only be done by solving a series of nonlinear algebraic equations. This paper presents a set of equations for three special conditions. The experimental verification of operating points that are predicted for such a load sensing system is pre-sented. The three regions are established theoretically and are verified experimentally. It is found that the operating points undergo a noticeable change when in transition from one region to another (as dictated by variations in load pres-sure or orifice area). It was also found that the agreement between the predicted and measured operating points was quite satisfactory and could be used with confidence in future studies.

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Author Biographies

Duqiang Wu, Department of Mechanical Engineering, University of Saskatchewan 57 Campus Drive, Saskatoon, Saskatchewan, Canada, S7N 5A9

Duqiang Wu Graduate student for Ph.D. at present, Me-chanical Engineering Department, University of Saskatchewan in Canada. Master (1984) at Nanjing University of science and Technology in China. Engineer (1986) at Shaanxi Mechan-ical and Electrical Institute in China. Visiting Scholar (1997) at University of Illinois at Urbana-Champaign.

Richard Burton, Department of Mechanical Engineering, University of Saskatchewan 57 Campus Drive, Saskatoon, Saskatchewan, Canada, S7N 5A9

Richard Burton P.Eng, Ph.D, Assistant Professor Mechanical Engineering, Professor, Mechanical Engineer-ing, University of Saskatchewan. Burton is involved in research pertaining to the applica-tion of intelligent theories to control and moni-toring of hydraulics systems, component de-sign, and system analysis. He is a member of the executive of ASME, FPST Division, a member of the hydraulics' advisory board of SAE and NCFP and a convenor for FPNI.

Greg Schoenau, Department of Mechanical Engineering, University of Saskatchewan 57 Campus Drive, Saskatoon, Saskatchewan, Canada, S7N 5A9

Greg Schoenau Professor of Mechanical Engineering at the University of Saskatchewan. He was head of that Department from 1993 to 1999. He ob-tained B.Sc. and M. Sc. Degrees from the University of Saskatchewan in mechanical engineering in 1967 and 1969, respectively. In 1974 he obtained his Ph.D. from the Universi-ty of New Hampshire in fluid power control systems. He continues to be active in research in this area and in the thermal systems area as well. He has also held positions in numerous outside engineering and technical organiza-tions.

Doug Bitner, Department of Mechanical Engineering, University of Saskatchewan 57 Campus Drive, Saskatoon, Saskatchewan, Canada, S7N 5A9

Doug Bitner MSc. Departmental Assistant Mechanical Engineering, University of Saskatchewan. Manager Fluid Power Laboratory and Control Systems Laboratory University of Saskatche-wan.

References

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Published

2002-08-01

How to Cite

Wu, D., Burton, R., Schoenau, G., & Bitner, D. (2002). ESTABLISHING OPERATING POINTS FOR A LINEARIZED MODEL OF A LOAD SENSING SYSTEM. International Journal of Fluid Power, 3(2), 47–54. Retrieved from https://journals.riverpublishers.com/index.php/IJFP/article/view/625

Issue

2002: Vol 03 Iss 2

Section

Original Article