Position Control of Low Cost Brushless DC Motor Using Hall Sensor

This paper concerns the research on position control of low cost brushless DC (BLDC) motor. Usually BLDC motors are controlled by using the hall-effect sensor in a low cost application. Based on the characteristics of back electromotive force (back EMF), the rotation information of rotor can be acquired from the hall sensor. During the one electrical cycle, the motor has six trigger signals for three phases. Speed and position of the rotor can be calculated by using hall sensor signal. The motor system has 30:1 gear ratio in experiment. Then, the number of hall sensor signal per one cycle is 180. Using the dsPIC33FJMC804 CPU as controller, some experiments were performed with the prototype which is the surface-mounted permanent magnet motor. Currently it is being developed for air intake system of vehicle.