OPTIMAL TUNING OF A PRACTICAL DIGITAL PID CONTROLLER

Optimal Tuning of a practical digital PID controller is studied by using the performance indices such as ITAE. IAE. ITSE, and ISE. A simplex searching method that uses the flexible polyhedron is used to find the optimal parameters in the controller. Tuning relations for each of the controller parameters are correlated into the forms that have been used by C.L. Smith and his co-workers. That is:

P = A(θ/γ)^B

or

P = A(θ/γ) + B.

It is noted that the present tuning relations are more practical in determinations of PID parameters when digital computers or micro-processors are used to implement the practical PID control. For control practice, the use of the existing tuning relations without precautions may result in poor performance in some cases.