APPARATUS AND METHOD FOR CONTROLLING A SERVOMOTOR.

摘要

A method for controlling a servomotor when reversing the direction of a feed shaft of a machine tool using said servomotor including the steps of estimating a friction torque by providing disturbance torque estimating means for estimating a disturbance torque (Step S2), dividing a value of a speed loop integrator into a friction torque component and an acceleration torque component (Step S3), obtaining an integrator target value when said servomotor is reversed by reversing the signs of said acceleration torque component and friction torque component (Step S4), performing a backlash acceleration correction by using as a backlash acceleration amount what is obtained by applying a certain offset amount to a speed command so that said integrator target value (Step S9) is reached. A friction torque is estimated by using an automatically estimated ratio (torque constant/inertia), whereby a proper backlash acceleration correction is possible, thereby reducing the quadrant projection.