A Design Method of Reference Model for near Time Optimal Model-Following Servo Controller: A Case Study for Multi-Zone Heating System with Input Saturation

This paper proposes a design method of reference model for model-following servo (MFS) control which overcomes the difficulty of control input saturation. One typical application of MFS control is heating and/or cooling plate control of semiconductor wafer fabrication. The control object is inherently MIMO (Multi Input Multi Output) system with interaction and input saturation and requires both temperature uniformity and faster response. MFS control is a well-known effective technique for tracking control of MIMO system with interaction and disturbances. However input saturation obstacles the accomplishment of the control requirements In order to overcome this difficulty we introduce a new design method of reference model and input signal based on master-slave step response tests and near time optimal simulations. Experimental results indicate the effectiveness of the proposed reference model design method which realizes both faster response and better uniformity.