A Novel PID Controller Cascaded With Higher Order Filter for FOPDT With Real Time Implementation

Abstract

This work describes the design of Proportional-Integral-Derivative(PID) controller for stable and unstable First Order Processes with Dead Time(FOPDT). PID controller is augmented with a higher order filter. The PID and the filter parameters are analytically derived using polynomial method. Higher order time delay approximation has been considered for improved accuracy. Maximum sensitivity(MS) based analytical tuning procedure is presented and concrete tuning guidelines are derived. The suggested technique is validated against delay dominant and nonlinear processes. In terms of the various performance indices, the suggested technique is compared to existing methodologies. The proposed method is tested on a real time process to verify the practical application.

Keywords

• Unstable process
• dead time
• PID
• maximum sensitivity
• Pade-2