Data collection method for motor load inertia identification

摘要

PURPOSE:To remove the cogging torque component from an acceleration waveform even in low speed rotation by observing the response waveform (n) times at intervals 1/n of the motor shaft center angle for one cyclic period of the cogging torque, and averaging the observed values in (n) pieces. CONSTITUTION:A lamp command for the position is given from an upper order controller 11 to a servo controller 12, which determines the acceleration by one time differentiating the output of the speed using a step command of the speed obtained through one time differentiation of the position command. The motor 8 shaft center angle for one cyclic period of the cogging torque is divided in equal segments in (n) pieces, and the acceleration response waveform for the step input is observed (n) times while the rotation starting angle is shifted at intervals i/n of the center angle. Influence of the cogging torque can be removed from the observed waveform by averaging the observed response waveform values in (n) pieces at the same observation time counted from the rotation starting time. An accurate load inertia 9 is identified by the use of this waveform obtained. Parameters of the control system are set using the presumed inertia moment obtained.