Enhanced design of PI controller with lead-lag filter for unstable and integrating plus time delay processes

Abstract

Abstract In this work, a proportional–integral (PI) controller with a set point filter is designed using the direct synthesis method for unstable plus time delay process. The Suggested method involves design parameters whose suitable values are recommended based on robust stability and robust performance constraints. The absence of derivative term makes PI controllers less sensitive to noise and, therefore, PI controllers are more preferable than PID in industrial applications. Despite a simple control architecture, the proposed method gives improved or comparable performance to previously presented approaches, which are comparatively complex. Four case studies are considered to evaluate the suitability and superiority of the suggested control technique. Proposed controller may be applied to the integrating plus time delay plants after some elementary transformations in the process model.