OPTIMIZED FUZZY LOGIC VIBRATION CONTROL OF A FLEXIBLE SPACE STRUCTURE

A fuzzy logic based vibration control system for a multi-input, multi-output (MIMO) STABLE platform system has been studied in this paper. In order to avoid the complexity of designing an MIMO fuzzy control system, a standard fuzzy logic control frame has been proposed, which converts the different universes of discourse for different input and output variables into a standard universe of discourse, by selecting appropriate scaling factors for each of the fuzzy logic controllers. An MIMO fuzzy logic controller is converted into a scaling factor optimization problem by this standard fuzzy logic controller frame. At the same time, the existence of co-situated sensor/actuator pairs allows the designer to create only six fuzzy logic controllers for six sensor/actuator pairs. The position sensor measurements and their derivatives serve as the fuzzy logic controller inputs, which generate the control forces for the corresponding actuators. The resulting vibration control system is robust against external disturbance forces and parametric variations. In addition, two new FLC plus Integral control configurations improve the robustness of fuzzy logic based vibration control systems against extended applications of external disturbance forces. Simulation results demonstrate the improved performance and robustness of the designed STABLE platform fuzzy logic based vibration control system.