Patent ID: 8204641

Claim:
A traction motor control apparatus for a vehicle that is provided with a traction motor as a traction power source and a rotation angle detection means that outputs first rotation data each time the motor rotates by a certain angle to show that effect, outputs second rotation data each time the motor rotates by a reference angle of 360/n degrees (n being an integer larger than or equal to 1) larger than the certain angle to show to that effect, and controls power supply to the motor using the first and second rotation data outputted from the rotation angle detection means, the traction motor control apparatus including a correction means for correcting the first rotation data and outputting a correction result as corrected rotation data, and being configured to control power supply to the motor based on the corrected rotation data outputted from the correction means, wherein the correction means comprises: a certain angle rotation time prediction means that measures, at each timing at which an actual detected angle as an actual rotation angle of the motor shown by the first and second rotation data changes by a predetermined prediction angle width, an elapsed time from when the actual detected angle reached a value earlier than a present value by the reference angle to when the actual detected angle has reached the present value, and predicts a time necessary for the motor to rotate by the certain angle based on the measured elapsed time thereafter; a predicted rotation data generation means that assumes that the motor has rotated by the certain angle during elapse of the predicted time each time the predicted time predicted by the certain angle rotation time prediction means elapses from an angle prediction start timing as an output timing of the second rotation data, and generates the predicted rotation angle as predicted rotation data; and a corrected rotation data update means that compares a predicted rotation angle shown by the predicted rotation data presently generated by the predicted rotation data generation means with a corrected rotation angle shown by the corrected rotation data presently being outputted from the correction means, updates the corrected rotation data to be outputted such that the corrected rotation angle and the predicted rotation angle coincide with each other at each output timing of the first rotation data, and initializes the corrected rotation data at each output timing of the second rotation data such that the corrected rotation angle shown by the corrected rotation data has a same value with the predicted rotation angle shown by the predicted rotation data and the actual detected angle.