Control system with improved robustness to disturbances

摘要

A control system has a detecting block for obtaining a detected signal corresponding to a controlled variable of a controlled system and a controlling block for supplying the controlled system with a control signal corresponding to the detected signal. The controlling block comprises an error block for producing an error signal corresponding to the detected signal at a detecting block, a memorizing block having a plurality of memorized values corresponding to the error signal, an output block for producing the control signal by mixing the error signal and one or more memorized values of the memorizing block and a adapting block for changing the number of a plurality of memorized values of the memorizing block according to a frequency of fluctuation of a disturbance source. The memorizing block renews the memorized values sequentially and periodically with a value corresponding to a mixed value of the error signal and a set of N memorized values, the N memorized values having been renewed at intervals of L renewing cycle periods, where each of N and L is an integer at least equal to 2.