Construction of an inverse model with cutoff filter and its application to a model feedback control system

Abstract

An inverse system for a given time-invariant system has been used as a compensator. However, in control systems which include traditional inverse systems, the adverse effects of sensor noise may seriously influence the systems, because the inverse system generally has high gain in the high-frequency area. Therefore, in these control systems other compensators than the inverse system must be constructed with complex properties. In this paper, a method of design of a new inverse model with cutoff filter for the Model Feedback Control System (MFCS) is proposed. The inverse model designed by the proposed method is an approximate inverse model for a given model. The approximation can be evaluated by the norm criterion for the difference between the model and the biproper transfer function used for construction of the inverse model. In order to demonstrate the usefulness of the proposed inverse model, this inverse model is applied to the MFCS. By theoretical and numerical analysis it can be shown that the proposed inverse model can reduce sufficiently the effects of sensor noise in the MFCS. © 2000 Scripta Technica, Electr Eng Jpn, 133(4): 79–90, 2000