A Nonlinear PD Controller Design and Its Application to MOV Actuators

This paper proposes a novel design method to control the opening and closing of a valve connected with a motoroperated valve actuator. In the structure of the proposed controller, a nonlinear gain is connected in series with the linear proportional-derivative controller with a first-order filter in the denominator. The nonlinear gain is described by a simple function of the error between the set-point and the measured output. The controller parameters are optimally tuned using a genetic algorithm (GA) so that a given objective function can be minimized. The stability of the closed-loop system is assessed using the Popov stability criterion. Simulation works are done to validate the effectiveness of the proposed method.