PI/PID controller tuning via LQR approach

This paper presents a new optimal PI/PID controller tuning algorithms for low-order plus time delay processes via the LQR approach. A new criterion for selection of the Q and R matrices is proposed, which leads to the desired natural frequency and damping ratio of the closed-loop system. The examples with various dynamics are included to demonstrate the effectiveness of the tuning algorithms and show significant improvement over the existing PID tuning methods.