Virtual disturbance loop-shaping for multi-loop PID control

In this paper, a new tuning method of the multi-loop PID controller for loop shaping is proposed. The loop shaping problem of maximizing the integral gain of the PID controller under the maximum sensitivity constraint is reduced to a linear programming problem. The constraints on the PID gains are directly derived from many data obtained by filtering the plant responses with many bandpass filters. The identification of the plant model is unnecessary.