안티와인드업을 결합한 PID 제어기의 유전알고리즘에 기초한 동조

Abstract

Many practical processes in industry have nonlinearities of some forms. One commonly encountered form is actuator saturation which can cause a detrimental effect known as integrator windup. The integrator windup problem often leads to inconsistency between the controller output and the process input. As a result, the tuning of the process based on its linear model may exhibit a strikingly different behaviour from its implementation as soon as an actuator saturation affects the operation and even the stability can be lost. Therefore, a strategy of attenuating the effects of integrator windup is required to guarantee the stability and performance of the overall control system.

In this thesis, a strategy in tuning a proportional-integral-derivative (PID) controller with an anti-windup scheme is presented to enhance the tracking performance of the PID control system in the presence of the actuator saturation. First, existing anti-windup schemes are investigated and an effective anti-windup scheme is adopted. Then, the parameters of the PID controller incorporating the anti-windup scheme are optimally tuned by a genetic algorithm (GA) such that the integral of absolute error is minimized. A set of simulation works on three high-order processes demonstrates the benefit of the proposed method.