Multi-Objective Optimization Approach to the Pi Tuning Problem

This paper presents a simple PI control design approach for first order plus dead time processes. The design method aims to obtain good responses to setpoint and load disturbance signals, good robustness to model errors and small variation of the control signal, simultaneously. The design problem is formulated as a multi-objective optimization problem. Using multi-objective genetic algorithms, the optimization problem is solved and optimal PI tuning formulae are developed. Simulation results demonstrate the effectiveness of the proposed method in coping with conflicting design objectives.