Practical Modelling and Control System Design Methods for CAE Systems

In this paper, practical modelling and control system design methode for CAE (Computer Aided Engineering) systems are presented. The Partial Model Matching method (PMM) is effective in designing conventional PID (Proportional, Integral, Derivative) control systems used widely in industrial processes, and some extended types of PID control systems such as decoupling PID control systems and digital PID control systems. In order to design a control system by the PMM method, a transfer function for process dynamics that has a simple structure is needed. Furthermore the cut-off frejuency characteristics that determine the stabilty and response charscteristics of the control system are essential for control system design. Thus, an effective modelling method is proposed that identifies a transfer function by the response data that shows the cut-off frequency characteristics exactly and reduces it to a simple Structured transfer function. The combination of the modeling method and the PMM method is applicable to various dynamics, such as processes with delay time, dead time, overshooting, reverse shooting and oscillation. A CAE system developed on a laptop personal computer using the methods is outlined.