MOTOR CONTROL

摘要

PURPOSE: A motor control is provided to calculate the offsets in the current sense circuit from the top zero current sample and bottom zero current sample by separately filtering streams of top zero current samples and bottom zero current samples using a first order(digital) low pass filter. CONSTITUTION: A method comprises the steps of monitoring the current flowing into or out of the windings of the motor using a current measurement means to produce an output signal indicative of the current; measuring the output of the current measurement means when the instantaneous current flow through the current measurement means is known to be substantially zero; and producing a modified output signal which is compensated for any differences between the actual measured output signal value and an ideal output signal value. The method enables any drift in the output signal to be compensated "on-line" whilst the motor is running.