A Minimal Fuzzy Gain Scheduling Speed Controller and Torque Compensation for the Variable Sampling System of BLDC Motors

A minimal fuzzy gain scheduling speed controller with torque compensation for brushless DC (BLDC) motors is proposed in this paper. Because the speed measurement of BLDC motors is based on Hall sensors, which is build in for commutation purpose originally, the intervals of speed feedbacks are variable. This variable sampling system response of low resolution position sensors structure is different from fixed sampling system. A minimal fuzzy gain scheduling control is used to handle the variable sampling system, fuzzy logic is used to combine the best PI controllers of different speed to get a suitable gain. And, to speed up the response under dynamic torque loading, a simplified torque load estimation and compensator is proposed, gain scheduling is also employed to adjust its output for variable sampling system. The simulation results show the controller work well under different speed commands and torque loads.