Patent ID: 8299742

Claim:
A method for decelerating a motor in a computer numerical controlled (CNC) machine tool, the method comprising: calculating a present rate of deceleration D P , for a motor of a motor drive system in a CNC machine tool, based on a present speed S P of the motor, a reference speed S R of the motor, and a reference rate of deceleration D R of the motor; and decelerating the motor from the present speed S P according to the present rate of deceleration D P , wherein the motor drive system comprises a maximum power rating, the maximum power rating defining a maximum power, generated by the motor while decelerating, that can be dissipated without overloading the motor drive system, wherein the reference rate of deceleration D R is a rate of deceleration such that power, generated by the motor while decelerating from the reference speed S R according to the reference rate of deceleration D R , is equal to the maximum power rating, and wherein power, generated while decelerating the motor from the present speed S P according to the present rate of deceleration D P , is equal to or less than the maximum power rating.