Modeling and Cascade PID Controller Design of a Spinbath Circulation Process

This paper reports the development of a cascade PID type control scheme for a MIMO spinbath circulation process regulation. In the proposed scheme, the dynamic model of the complete spinbath circulation process is first developed using concepts from fluid dynamics. Reduction of the obtained model through lumping of identical processes as well as linearization techniques is then conducted to obtain a simplified MIMO linear system with cascading control structure. A cascade PI control configuration is then constructed to achieve simultaneous control objectives in the interacting process variables of the developed simplified model [1]–[3]. More specifically, the proposed cascade controller is of the type of summed setpoint cascade PI that is selected for its cost-effectiveness and computational efficiency. It combines a summed setpoints to simultaneously manages multiple inputs, as well as cascades of faster inner disturbance rejection to allow for the minimization of the overall process' output deviations. Simulation results for constant as well as changing setpoints are then presented to demonstrate the effectiveness of the proposed modeling and cascade control schemes.