Research on the Novel AC Servo Motor With Position Detection Function

With the advent of the full digital control system, the AC servo motor with the high efficiency, simple structure features and widely used in national defense, industrial and agricultural production, and daily life. In the practical application, the precision position of servo motor relies on the rotor position information. Since the external displacement sensor method has disadvantages such as volume increase, high manufacturing cost, and inconvenience of installation, also, sensorless detection way exists unstable parameter and it is hard to implement, this paper presented a new detection method. In the proposed method, tunnel magnetoresistance（TMR） and time grating technology are combined to come true the position detection function. Besides, detection parts are embedded into the motor without destroys structure. Finally, taking the permanent magnet synchronous motor（PMSM） as an example, the feasibility of this method was proved by simulation design analysis and prototype experiment. Experimental results show that the measured accuracy of this method reached 1.8°. Obviously, the embedded position detection method overcomes the known defect in position detection method and provides a novel approach for the position detection of the motor.