Fuzzy control of multivariable nonlinear servomechanisms with explicit decoupling scheme

This paper deals with the problem of controlling multivariable nonlinear servomechanisms by means of fuzzy approaches. A specific system under consideration is a passive nonlinear line-of-sight (LOS) stabilization system with strong interactions between two channels. By using the concept of decentralized control, a control structure is developed that is composed of two control loops, each of which is associated with a single-variable fuzzy controller and a decoupling unit. A simplified fuzzy control algorithm is used to implement the fuzzy controller. We propose two novel approaches to designing the decoupling units. The first one is based on the theory of fuzzy reasoning whereas the second scheme relies on the principle of adaptation. Extensive simulation studies on the LOS system have demonstrated the feasibility and effectiveness of the proposed approach.