A study of fuzzy variable structure sliding mode control

The main objective of this paper is to study the dynamic behavior and steady-state performance of fuzzy variable structure sliding mode control system (FVSSMCS). Two parts of discussion are presented: the study of normal control phase and sliding-mode control phase in FVSSMCS respectively. In the study of normal control phase, we present a new control law that can ameliorate the dynamic performance of FVSSMCS based on the term of hitting value which represents the ability to control the system states to hit a user-defined sliding hyperplane. Moreover, we have studied the sliding-mode control phase in FVSSMCS and made the conclusion that the scope of the sliding hyperplane has been extended so that the chattering can be decreased. Thus the robustness of the system is reinforced because of the fuzzification of the sliding hyperplane. Simulation results of the huge-ship heading control support the study of FVSSMC in this paper.