Passivity-driven fuzzy logic control of a multidegree-of-freedom reaction compensating system

Abstract

This paper presents the passivity-driven fuzzy logic (FL) concept for the active control of a multi-degree-of-freedom reaction compensating platform system, which is designed and used for isolating vibratory disturbances of space-based devices. The physical model used is a scaled-down two-plate platform system. In this work simulation is performed and is to be presented in the paper. According to the desired performance specifications, a full range of investigation regarding the development of an FL stabilization controller for the system is conducted. Specifically, the study includes four stages: comprehensive dynamic modelling of the reaction compensating system; analysis of the dynamic responses of the platform system when it is subjected to various disturbances; design of a passivity-driven fuzzy logic controller which is capable of filtering the vibratory disturbances transmitted to the bottom plate of the platform system; and performance evaluation of the developed FL controller through computer simulations. 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 that 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 compensating systems also reveals that the FL-controlled system achieves significant improvements in reducing vibratory accelerations over passive systems.