Method of controlling a control system with improved robustness to disturbances

摘要

A control method has a detecting step for obtaining a detected signal corresponding to a controlled variable of a controlled system and a controlling step for supplying the controlled system with a control signal corresponding to the detected signal. The controlling step includes an error signal producing step for producing an error signal corresponding to the detected signal at intervals of a detecting period of time, a storing step for producing a plurality of stored values corresponding to the error signal, and a control signal producing step for producing the control signal by mixing the error signal and one or more stored values of the storing step. The storing step renews the stored values sequentially and periodically at intervals of a renewing cycle period of time equal to Q times the detecting period, each with a value correponding to a mixed value of the error signal and one or more of the stored values having been renewed at intervals of L renewing cycle periods, where each of Q and L is an integer at least equal to 2. Preferably, the storing steps includes a filtered error signal producing step for filtering the error signal with a filter having a low-pass filter characteristic for producing a filtered error signal, and the mixed value is obtained by mixing the filtered error signal and the one or more of the stored values.