Optimal Self-Tuning of PID Controllers

A self-tuning PID controller has been developed that uses the well-known technique of direct-search optimization. An objective function that measures the quality of control performance is optimized by a succession of small adjustments to the three PID tuning constants. Because the optimization is driven by actual performance and no assumptions are made about process dynamics and disturbance behavior, this technique provides optimal tuning for almost any loop that can be controlled by PID.