Robust position control of a perturbed electrical servo drive system via the adaptive fuzzy sliding-mode technique

A novel adaptive fuzzy sliding-mode control (AFSMC) system for high-precision position control of a perturbed electrical servo drive is developed in this paper. The proposed AFSMC system is designed via the approximation ability of a fuzzy system to mimic the good behaviour of a total sliding-mode control (TSMC) system, which is designed without the reaching phase of a conventional sliding-mode control (SMC). In the developed system, a priori knowledge of the system information is not required. Moreover, the gradually increasing estimate upper bound, which may induce the control effort into saturation and excite unstable system dynamics in some conditions, would not exist. In the proposed controller, the adaptive tuning algorithms are developed in the sense of the Lyapunov stability theorem, so that system-tracking stability can be guaranteed. Finally, the effectiveness of the proposed control scheme is verified via the experimental results of a field-oriented control permanent magnet (PM) synchronous motor.