U OF M COLLEGE OF ENGINEERING
CONTROL SEMINAR SERIES
WINTER TERM 1998

Mechanical and Industrial Engineering
University of Illinois at Urbana-Champaign

alleyne@uiuc.edu

Friday, January 16, 1998
4:00 - 5:00 pm
1200 EECS

Title: Force Control of Electrohydraulic Servosystems

• Abstract
  
  This talk will examine the control of an extensively used actuation method: the hydraulic servosystem. A brief history of the field will be presented as a background. The academic activity levels were quite high post WW2 and into the 1970's but, strangely enough, dropped off dramatically with the introduction of the microprocessor. The talk will then focus on a particular control problem associated with hydraulic servosystems under electronic control: force control. The problem will be motivated by an automotive active suspension application. Fundamental limitations to the simple linear control of this problem will be presented. It is shown that the position control problem is relatively simple and can be easily handled. However, the force control problem becomes much more difficult. A nonlinear control approach is taken to solve the problems presented. One or more (time permitting) theoretical analyses will be presented as a method for achieving accurate nonlinear force control. Additionally, due to the unknown nature of some of the critical system parameters, an adaptive algorithm is coupled to the nonlinear controller. Lyapunov stability analysis guarantees asymptotic tracking provided the system satisfies the stated assumptions. Experimental results verify the predictions made by the theory but also point out where some of the initial assumptions were modified.

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  Biosketch

  
  Andrew Alleyne graduated Magna Cum Laude from Princeton University with a B.S.E. in Aerospace Engineering in 1989. He received his M.S. degree and Ph.D. degree in 1992 and 1994, respectively, from The University of California at Berekeley's Mechanical Engineering Department. He is presently an Assistant Professor in the Department of Mechnical and Industrial Engineering at The University of Illinois, Urbana-Champaign. His research interests focus on the modeling, analysis and control of mechanical systems with a focus on Automotive and Manufacturing Systems. He is a recipient of a 1996 NSF CAREER award and has been a faculty fellow at Ford Scientific Research Labs and Caterpillar Technical Center. In addition he worked briefly with the Jet Propulsion Laboratory prior to graduate school.

© UofM College of Engineering Control Research Group - December 1997
bethi@umich.edu