Method for Measuring Initial Position of Motor Rotor of a Digital Servo System

The inaccurate measurement of initial position of motor rotor when the motor starts is a problem existing in a servo system applying increment photo-electricity pulse coder.The initial position of motor rotor not only affects positioning precision, also has effect on start-performance. This paper proposes a method for measurement of initial position of motor rotor.The initial position can be measured accurately through controlling a given-position current vector of motor stator.Experimental results verify that the start-performance of motor can be improved and the motor only has some tiny vibrancy during the course of measurement.