Dynamics and control of a parallel mechanism for active vibration isolation in space station

Vibration in the microgravity environment is with the characteristics of low frequency, small amplitude, and randomness. Control method of an active vibration isolation system with parallel mechanism applied to space application, which is effective for disturbance suppression, is proposed. The dynamics model of active vibration isolation system with payload is represented via Kane’s method, thereafter the description in state-space linearization is introduced. System properties and step responses of the systems in open loop are evaluated in detail. Controllability and observability of the system are checked by state-space equations of the system. The state feedback decoupling with double-loop proportional-integral-derivative (PID) control method is adopted as the system controller to design the decoupling matrix and the PID controller. For improving the properties of the system, a control system with H-infinity method is also designed and evaluated. Finally, various types of simulation results are demonstrated to verify the effectiveness of the active vibration damping system proposed.