Robust Bounded Control for Fuzzy Mechanical Systems: Fuzzy Optimal Design and Inequality Constraint Reorganize

This article presents a fuzzy optimization design for the tank bidirectional stabilization system with a fully electric actuator. The uncertainty in the system is (possibly fast) time-varying but lies in the fuzzy set. First, a machine-electric coupled state-space equation that can accurately describe the state transition of the system is established by considering the assembly relationship among components. Second, inequality constraints are proposed to reduce the range of steady-state error fluctuations. By constraint reorganization, a new system containing only equality constraints is constructed to replace the original system. The control problem for systems with inequality constraints is solved. Third, fuzzy set theory is used to characterize the “fuzzy” features of the uncertainty in the system more accurately, and robust control with parameters to be determined is proposed. The optimal control parameter is selected by establishing and minimizing a fuzzy performance index, which weighs the effectiveness and cost of control. Thus, the contradiction between short time and high precision control performance due to the fast movement of the tank is solved. This article is the first to consider the tank bidirectional stabilization system with a fully electric actuator as a fuzzy mechanical system with inequality constraints and conduct an optimization design after proposing an error-controllable control strategy.