Autotuning of Parallel Cascade Control using Setpoint Relay

A new approach to tune the PI controller for parallel cascade control using setpoint relay autotuning method is proposed in this paper. The setpoint relay autotuning is found to be effective as that of the relay feedback method without switching off existing controller. The proposed method is found to be more advantageous for finding out ultimate gain and ultimate period and tested in computer simulation using various tuning methods. The results show that reasonable control performance can be achieved using IMC-PID method.