Abstract: The actuating legs of Stewart platform are usually moving with variable velocity because of the time-varying Jacobi matrix between operating space and joint space. Due to the variable velocity and the inherent differences in the system there is motion non-synchronization and coupling disturbance force among the linear hydraulic actuators. They influence the smooth running of the platform. Through analyzing the source and effect of the disturbance force of joints and by taking the inverse dynamics of ideal track of system as the reference model, an adaptive fuzzy compensator is designed to realize force/position hybrid control to keep the actuating legs in synchronism and reduce the platform jitter as well as adjustment time, thereby effectively improving the whole tracking performance of the system.

Key words: Adaptive fuzzy control, Dynamics, Force/position control, Interference force compensation, Stewart platform