Passenger ride comfort has been one of the major issues of vehicle designs. The most efficient way to achieving better ride quality is to improve the control of vehicle suspension systems. This paper focuses on developing a robust control algorithm for vehicle suspension systems, which can handle harsh road conditions as well as mechanical variances of suspension systems while providing a comfortable ride. Specifically, a model reference self-tuning fuzzy logic control scheme which consists of a primary and a secondary controller is proposed. The primary controller performs the major control function of the actual sprung mass acceleration. The secondary controller, however, is used to tune the output membership function of the primary fuzzy logic controller on line such that it is capable of adapting process variations such as sprung mass change, spring and damper rate variations and harsh road conditions. T h e simulation results show that the performance of the suspension system controlled by the proposed controller is much better than that of passive suspension system. T h e simulations a n d comparison study also demonstrate the superior robustness of the proposed fuzzy logic controller over the conventional controller for active vehicle suspension system.

This paper presents the development of a general purpose fuzzy logic (FL) control methodology for isolating external vibratory disturbances of space-based devices. The physical model used is a scale-down two-plate reaction compensating platform system. According to the desired performance specifications, a full range of investigation regarding the development of an FL stabilization controller for the system is conducted. The performance of the FL controller is tested using different scenarios such as variances of passive reaction compensating components and external disturbance load. It is shown that the proposed FL controller is robust in that the resultant active system closely follows the performance of the prespecified ideal reference model. The comparative study of the performances of the FL controlled active reaction and noncontrolled passive reaction compensating systems also reveals that the FL controlled system achieves significant improvements in reducing vibrations over passive systems.

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