Ride Comfort Improvement of a Semi-active Vehicle Suspension Based on Hybrid Fuzzy and Fuzzy-PID Controller

The development of vehicles providing maximum drive comfort and handling stability is one of the design targets for car manufacturers. This paper proposes a hybrid fuzzy and fuzzy-PID (HFFPID) controller for a semi-active quarter-car with three degrees of freedom utilizing a magneto-rheological (MR) shock absorber. The control objective is to amend the ride quality of the vehicle. The proposed controller comprises a fuzzy-self-tuned proportional-integral-derivative (FSTPID) controller, a fuzzy-logic controller (FLC) and a fuzzy selector (FS). Based on the error between the output and its set point, the fuzzy selector selects which controller should play the greatest effect on the control system. The effectiveness of the proposed control strategy is analysed through simulations involving excitations for a bump road and a random road profile in time domain. The results show that the HFFPID controller has the best performance in reducing the car body acceleration, suspension working space and seat acceleration response compared with the uncontrolled as well as FLC-and HFPID controlled-cases. Hence, the best ride quality response is provided by the HFFPID controller as compared to all the other suspension systems considered in this paper.