Performance assessment of PID controller with time-variant disturbance dynamics

A method is proposed for performance assessment of PID control loops subject to time-varying disturbance dynamics, which is often observed in industrial processes. The proposed method optimizes overall performance of the processes and presents a PID tradeoff curve which provides a useful lower bound on the achievable performance of the PID controller in terms of both the most significant disturbance rejection and the representative disturbance rejection. One can choose an optional benchmark to assess the PID control performance according to the tradeoff curve. The developed performance assessment technique is illustrated by simulation and industrial examples.