Discrete IMC controllers automatic tuning method based on relay feedback identification

In this paper, the technology of relay feedback is first extended to the discrete field of controllers design assignment in the Internal Model Controller (IMC) configuration to achieve the automatic tuning in the complex dynamic factory circumstance. It is shown that this proposed method realizes automatic tuning easily based on the relay identification. For one thing, an improved simple proof of this identification and control procedure is provided. For another thing, this new controller entitles stronger disturbance rejection and better robust performance and the dynamic response compared with the former methods which are demonstrated by several simulation experiments. Furthermore, the proposed method successfully applies to the First-Order Plus Dead-Time (FOPDT) system with large time delay while many other traditional Proportional-Integral-Derivative (PID) self-tuning strategies even fail to converge in process control.