ABSTRACT This paper investigates the problem of fuzzy adaptive predefined time full‐state error constraints for permanent magnet synchronous motor systems. This study employs fuzzy logic systems (FLSs) to handle unknown nonlinear dynamic functions. A state observer based on fuzzy logic systems is utilized to estimate unmeasurable states. By utilizing a general potential Lyapunov function, predefined‐time stability theory, combined with dynamic surface control (DSC) technique and backstepping recursive technique, a predefined time full‐state error constraints control strategy is proposed. By applying predefined time Lyapunov stability theory, it is proven that all signals in the closed‐loop systems remain bounded and the tracking error converges within a predefined time. Finally, the effectiveness and feasibility of the proposed method are verified through simulation results.
Liu et al. (Tue,) studied this question.