Brushless direct current motor, BLDC, composed of motor body and driver, is a typical mechatronics product. The motor without brush is the motor without brush and commutator (or collector ring), also known as commutator motor. The use of electronic commutator instead of mechanical brush and mechanical commutator not only inherits the excellent linear mechanical characteristics of DC motor, wide speed range, large starting torque and other advantages, but also avoids the strong mechanical brush and commutator of DC motor Forced contact causes a series of problems, such as complex structure, poor reliability, sparks and mechanical noise, which affect speed regulation accuracy, performance and life. It is more and more widely used in all kinds of drive devices with high reliability and long life.