An improved measuring system of rotor position angles of the sensorless direct drive servomotor

An improved measuring system of rotor position angles with a sensorless direct drive servomotor (DD motor) is considered. The authors previously presented a method of making a servo system with the DD servomotor without rotor position and rotating speed sensors. In the present work, they propose an improved sensorless servo system with the DD motor without a rotor position sensor. They adopted a PAM system by using a DC-DC power converter and a DSP for the calculation of the rotor position angle. Experimental results show that the accuracy of the measured values are improved effectively with this system