Implementation of intelligent PID auto-tuning

The authors present a particular implementation of expert control. Specifically, relay feedback proportional-integral-derivative (PID) autotuning is presented. The main characteristics of the implementation are the blackboard architecture of the knowledge base and the clear separation of heuristic logic from the numerical algorithms. Various heuristics have been implemented to give a number of desired features. The result is an intelligent PID autotuner. This implementation attempts to attain the following goals: to achieve stable control with a minimal amount of prior process knowledge; to improve control with increasing process knowledge; to automatically select appropriate controller structures (PI or PID); to monitor control performance; and to build a system such that the control knowledge and heuristics are easy to modify and extend