T-S fuzzy-model-based sliding-mode control for surface-mounted permanent-magnet synchronous motors considering uncertainties

This paper presents a new sliding-mode control (SMC) scheme based on Takagi-Sugeno (T-S) fuzzy model for surface-mounted permanent-magnet synchronous motors (SPMSMs). First, a global T-S fuzzy model is given to represent the nonlinear dynamics of the SPMSM. The proposed T-S fuzzy-model-based sliding-mode controller considers motor parameter uncertainties and unknown external noises, so it is robust against motor parameter and load torque variations. Also, the linear matrix inequalities with feasible performance constraints are used to design both the sliding surface and the sliding-mode controller, and the stability of the proposed controller is analytically proven. In this paper, a simple sliding-mode observer is used to estimate load torque information. The proposed observer-based control scheme is implemented by using a Matlab/Simulink simulation tool and a prototype SPMSM drive with a TMS320F28335 DSP. Finally, simulations and experiments have been performed to justify that the proposed observer-based control strategy can guarantee a better performance (i.e., faster dynamic response, less steady-state error, more robustness, etc.) than the conventional observer-based nonfuzzy SMC scheme when there exist motor parameter uncertainties and unknown external disturbances.