MODELING AND FUZZY-LOGIC CONTROL OF AN ACTIVE REACTION COMPENSATING PLATFORM SYSTEM

This article presents the application of the fuzzy logic (FL) concept to the active control of a multiple degree of freedom reaction compens ating platform system that is designed and used for isolation vibrator y disturbances of space-based devices. the physical model used is a sc aled down two-plate platform system. In this work, simulation is perfo rmed and presented. According to the desired performance specification s, a full range of investigation regarding the development of an FL st abilization controller for the system is conduced. Specifically, the s tudy includes four stages: comprehensive dynamic modeling of the react ion compensating system; analysis of the dynamic responses of the plat form system when it is subjected to various disturbances; dynamic resp onses of the platform system when it is subjected to various disturban ces; design of an FL controller capable of filtering the vibratory dis turbances transmitted to the bottom plate of the platform system; perf ormance evaluation of the developed FL controller through computer sim ulations. To simplify the simulation work, the system model is lineari zed and the system component parameter variations are not considered. The performance of the FL controller is tested by exciting the system with an impulsive force applied at an arbitrarily chosen point on the top plate. It is shown that the proposed FL controller is robust in th at the resultant active system is well stabilized when subjected to a random external disturbance. The comparative study of the performances of the FL controlled active reaction and passive reaction compensatin g systems also reveals that the FL controlled system achieves signific ant improvements in reducing vibratory accelerations over passive syst ems. (C) 1995 John Wiley & Sons, Inc.