Control Approaches through Time Weighted Error and Gain Margin tuning for Unstable Systems

Abstract

The Proportional Integral Derivative (PID) control strategy is very simple, robust, and sufficient to tune the low-order plus time delay model. On the other hand, the empirical PID controller has structural limitations in controlling the unstable processes. The closed-loop dynamics and structural mismatch can be analyzed intuitively to understand why the PID controller is not suitable to control the unstable processes effectively. Also, the conventional PID controller with minor structural variations designed to guarantee Optimal Gain Margin (OGM) tuning and Integral of the Time-weighted Absolute Error (ITAE) tuning, handles better than the performance offered by a conventional PID controller for an unstable process.