Sliding mode controller design based on fuzzy inference for non-linear systems

The authors propose a method of nonlinear feedback control, introducing fuzzy inference into the sliding mode control. The fuzzy inference is introduced to treat the nonlinearity of the system and to reduce the control chattering. A nonlinear system is expressed by fuzzy modeling which is composed of the weighted average of linear systems with fuzzy inference. Stability analysis of the fuzzy control system is carried out on the basis of fuzzy stability theory based on Lyapunov´s direct method. The proposed control method is applied numerically to the stabilizing control of an electric power system with an automatic voltage regulator and a governor. As a result, the large oscillation which indicates the nonlinear phenomenon is stabilized; the control chattering is reduced; and a good control effect which includes control stability is obtained