Grey fuzzy sliding mode control for uncertain systems

Aiming at grey box system with partial parameters uncertainty, a composite control strategy based on grey model compensation and sliding mode Variable Structure Control (VSC) is proposed. Sliding mode control is designed for certain part of the system. A fuzzy controller is introduced to tune the sliding parameter according to the state of sliding mode, which overcomes the undesirable chattering problem in VSC. A grey estimation model is used to compensate the parameter uncertain part of the system. Computer simulation results for a motion control system with model uncertainty show that the composite control strategy proposed is effective, and the problem of undesirable chattering in VSC and model uncertainty is overcome well.