A Simple Method for Automatic Tuning of PID-Controllers based on Process Parameter Estimation

Microprocessor-based tuning aids and self-tuning-methods for conventional PID-controllers are an important subject to industrial users. Some of the existing techniques use simple pattern-recognition, some use expensive optimization procedures. This paper describes a simple self-tuning-procedure for PI- and PID-controllers, which is based on discrete parameter estimation and application of slightly modified Ziegler-Nichols tuning-rules. Controller tuning has been simplified to the choice of the desired over-shoot of the PID-controlled closed loop system. The method is easy to implement in microprocessors and allows quick online-tuning of PID-controllers. Simulation results and a comparison with controllers tuned by an optimization procedure are presented.