Thrust Control of BLDC Thruster Motors by Observer-Based Robust Adaptive Fuzzy Control

In this paper, a new dynamical model is suggested for the Brush-Less DC (BLDC) thruster motors, by an observer-based robust adaptive fuzzy controller. The proposed control method utilizes an accurate thrust model which is more efficient than the other approach. The suggested scheme is very simple, accurate and robust, so that, a control method of thrust, torque, and speed of BLDC motors is available. Based on the adaptive fuzzy algorithm an observer-based estimator is presented that applies feedback error function as the input of the fuzzy system to estimate and adaptively compensate the external disturbance and unknown uncertainties of the system under control. Although the proposed controller scheme requires the uncertainties to be bounded, it does not require these bounds to be known. An H∞ robust controller is employed to attenuate the residual error to the desired level and recompense both the fuzzy approximation errors and observer errors. The proposed method guarantees the stability of the closed-loop system based on the Strictly Positive Real (SPR) condition and Lyapunov theory. Finally, in simulation studies, to demonstrate the usefulness and effectiveness of the proposed technique, a BLDC motor system is employed.