Integration of Back Calculation Anti Windup and Smith Predictor on PID Controller for Varying Time Delay System with Input Constraint

Abstract

Proportional Integral Derivative (PID) controller is still the most widely used controller in the industry. However, the presence of varying time delay and input constraint cause PID controller performance to deteriorate and produce unsatisfactory operation. This situation becomes worsening if the varying time delay and input constraint come simultaneously during system operation. To tackle this issue, this paper focuses on the integration of smith predictor and back calculation anti windup on PID controller (PID-BC-SP) towards improving the performance of PID controller due to simultaneous presence of uncertain time delay and input constraint on the system. The designated controller is tested on a first order plus dead time model of glycerin bleaching process plant in order to observe the performance of the controller. Results obtained show that PID-BC-SP produces a better performance and higher robustness as compared to PID, PID to anti windup and PID with smith predictor controllers, whilst handling simultaneous presence of input constraint and varying time delay.

Keywords

• back calculation anti windup
• input constraint
• pid controller
• smith predictor
• varying time delay system