Stabilization of the Mechanical Dynamics of a Road Load Simulator Using Classical Control Techniques

• Published in: Proceedings of the Institution of Mechanical Engineers. Part I, Journal of systems and control engineering Journal of systems and control engineering, 1992-05, Vol.206 (2), p.85-98
• Main Authors: Stringer, I A, Bullock, K J
• Format: Article
• Language: English
• Subjects: Computer simulation; Control charts; Control systems; Control theory; Loads (forces); Loop transfer functions; Mechanical engineering; Predictive control; Root locus; Speed control; Transfer functions
• ISSN: 0959-6518; 2041-3041
• DOI: 10.1243/PIME_PROC_1992_206_314_02

The open-loop transfer function of a complex hydrostatic pump-motor dynamometer system was derived from an analysis of the dynamics of the individual components. Many system components exhibit non-linearities; however, internal feedback mechanisms contribute to linearization of sub-systems. The resulting model, which was in good agreement with the system's open-loop performance, was used to predict the behaviour of the closed-loop system, this indicated that the system would be unstable. Classical control theory was used to analyse the performance of a number of stabilizing control strategies, with root locus plots, Bode diagrams and Nichols charts being used to assess the resultant performance. A lead compensation, designed as a differential controller, combined with a bi-linear gain was predicted to provide acceptable speed control. The performance of the system with this controller installed was found to satisfy the design requirements of speed of response, limited overshoot and zero steady-state error.