PPI CONTROLLER TUNING FOR USE WITH A HIGHLY OSCILLATING SECONDORDER-LIKE PROCESS

A PPI controller is investigated for set-point tracking associated with a highly oscillating secondorder-like process. The controller is tuned using the MATLAB optimization toolbox and five different errorbased objective functions. All the objective functions result in a same time response of the closed-loop control system to a unit step input. The unit step reference input time response of the control system has a zero maximum overshoot and a settling time of 16 seconds. It has an oscillatory nature for a response time up to 10 seconds. The simulation results using the PPI controller are compared with using I-PD, PD-PI, PIPD, PID + first-order lag and PID controllers. The PPI can compete with I-PD, PD-PI and PI-PD controllers regarding the maximum percentage overshoot. However, it cannot compete with all the other five controllers regarding the settling time.