An approach to automatic tuning of phase-lead and phase-lag compensators

An approach to the automatic tuning of phase-lead and phase-lag compensators is proposed. The procedure consists of three steps: an appropriate test signal is automatically generated; the new gain crossover frequency and corresponding gain are estimated: and the compensator parameters are determined. The method is used for a digital controller that can be easily implemented by microprocessors. The method is based on the assumption that the plant is stable and nothing guarantees the stability of the system. Therefore, when the autotuning procedure has been completed, the stability of the closed system must be checked. The method requires that the behavior of the system resembles that of a low-pass filter to ensure identification accuracy