Investigation of anti-windup Proportional-Integral controller with semi-decoupled tuning gains in motor speed control

Integral windup refers to a prevalent phenomenon that can occur in Proportional-Integral-Derivative (PID) control systems that employ integral control where the control output generated exceeds the operating limit of an actuator. Despite the system’s inability to respond further due to control output limitations, the integral controller perseveres in accumulating errors. The accumulation of error can lead to system instability and undesirable oscillations. Additionally, the dynamic response of the PID controller is also limited by the coupled tuning gain characteristics, complicating the process of gain tuning. The coupling and decoupling of the tuning gains are depending on the separation of the gains in the error dynamics of the system. In this study, a concept of semi-decoupled tuning gains in anti-windup controllers is proposed. The performance of the proposed controller was investigated through hardware simulation against conventional PI and existing anti-windup schemes and has demonstrated an overall improvement in its dynamic behaviour such as faster settling time and its ability to tune the system without significantly altering its damping ratio.