Effect of feedback variables on active fuzzy vibration control of micro-vibration isolation platform

Concerning the active vibration control problem of micro-vibration isolation platform, the physical model of the six-DOF platform was built. Fuzzy control of the modal decoupled subsystem with one degree of freedom was emulated with deviation of displacement, velocity and acceleration and the rate of change as the two-dimensional feedback variables respectively, and the displacement and acceleration response of the system was analyzed. The emulation results indicate that active fuzzy control can attenuate dramatically the displacement and acceleration response, especially at the resonant frequency of the platform. Comparing the three kinds of feedback variables, fuzzy control with feedback of displacement deviation and its rate of change exhibits the best isolation performance, and the acceleration response is attenuated about two orders of magnitude in contrast with passive isolation system. The isolation performance with feedback of acceleration and its rate of change is the worst relatively. Even the acceleration response is taken as the object variable, the best feedback variables for fuzzy control should be displacement error and its rate of change.