This paper presents an observer-based fuzzy sliding mode controller for sensorless Permanent Magnet Synchronous Motor (PMSM) drive based on the Field Programmable Gate Array (FPGA) technology. For enhancement of robustness, a sliding mode observer (SMO) is proposed to estimate first the current and back electromotive force (EMF), then to derive the flux angle. These estimated values together with the computed rotor speed of the motor are fed back for the control purpose in both the current loop and the speed loop.

This paper presents the design and evaluation of an observer-based integral sliding mode controller for sensorless Permanent Magnet Synchronous Motor (PMSM) drive based on the Field Programmable Gate Array (FPGA) technology. For enhancement of robustness, a flux angle estimator using an improved sliding mode observer is proposed to estimate the current and back electromotive force (EMF) as well as to derive the flux angle.

This article addresses the robust exponential stabilization problem of underactuated mechanical systems in the presence of bounded external disturbances using sliding mode control. Based on the Lyapunov method, a sufficient condition for the existence of the smallest possible ball which bounds the reduced-order sliding mode dynamics, is first derived in terms of linear matrix inequality (LMI). A sliding mode controller is then synthesized to guarantee that system state trajectories are exponentially convergent to another ball with a prespecified  onvergence rate.