| Brushless DC motor (BLDC) is a brand-new mechatronic motor based on the development of power electronics and the advent of new permanent magnetic material. Through the wide-spread application of BLDC in a variety of fields, the strength of sensorless control of BLDC is increasingly gaining acceptance. This paper successfully realized sensorless control system of BLDC based on Freescale DSP 56F8346 by adapting the back-EMF (back electromagnetic force) zero-crossing detection method.The state-of-art and some general control methods of BLDC are firstly discussed. The operating principle and composition of BLDC are illustrated, and its mathematical model is analyzed. Secondly Matlab/Simulink is used to conduct the simulation study of BLDC and its control system. The simulation model of BLDC is built from the viewpoint of modularization, in which the overall system is separated into multiple isolated functional modules. Considering the weakness of normal PID controller, a self-adaptive fuzzy-PID controller is designed. Simulation results indicate that this method can actually improve the control quality.With the self-designed power state board for BLDC and a ready-made DSP EVM (Evaluation Module) board, the hardware experimental system for BLDC sensorless control is constructed. The design of some major hardware circuits for the inverter, back-EMF sensing, current sensing, protection circuit, etc, is introduced in the paper.For the BLDC hardware experimental platform, corresponding embedded software is coded for the sensorless control of BLDC and the implementation of associated algorithms by using CodeWarrior IDE. Experiments are conducted on the BLDC sensorless control system, experimental results are given, and analysis of experimental results is presented. Finally, the further research trend of this subject is proposed.
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