Three control approaches for the design of car semi-active suspension (optimal control, variable structure control, fuzzy control)

The design of active or semi-active suspensions for modern cars is subject to real time contradictory requirements concerning on one hand ride comfort and on the other hand road holding and handling. However, due to the limitation of design methods for non-linear systems, the design of the suspension is based on a linear multivariable model; the performance is tested by simulation on more realistic models including non-linearities and delays. In this paper, the authors present, through the use of a quarter car model, the design of semi-active suspension with an optimal controller, a variable structure controller and a fuzzy controller. The efficiency of the approaches and the performance of the different controllers are compared. Experiments using these three approaches have been conducted a test bench, the results are described