Patent ID: 8471506
Filing Date: 2013-06-25
Classification: G01P,H02P

Abstract:
1. A motor control apparatus comprising: an electrical angle detecting portion including a resolver and a resolver/digital converter, the resolver in which an electrical angle of 360° corresponds to one cycle of an output signal is set smaller than a mechanical angle of 360°, the resolver/digital converter that converts a signal from the resolver into a digital value, the resolver/digital converter outputs a two-phase encoder signal corresponding to an electrical angle of a rotor of a motor, the two-phase encoder signal that includes an A-phase signal, a B-phase signal, and a Z-phase signal; a two-phase encoder counter that counts the two-phase encoder signal up or down according to the A-phase signal and the B-phase signal, and clears the count value when the Z-phase signal is input and outputs a digital value corresponding to the electrical angle; an electrical angle number detecting portion that is configured to detect a position of the mechanical angle to which an electrical angle indicated by the signal output from the electrical angle detecting portion corresponds, based on a change in a count value of the two-phase encoder counter, the electrical angle number detecting portion creates an extended count value in which a high order bit of the two-phase encoder counter is further extended to a value that corresponds to a mechanical angle of 360°, and outputs the extended count value, and when the count value of the two-phase encoder counter is cleared while the count value of the two-phase counter is being increased, the electrical angle number detecting portion clears the extended count value when the count value of the two-phase encoder counter right before being cleared exceeds a threshold value; and a motor controlling portion that is configured to determine a current command value based on a torque command value sent from outside the motor control apparatus, and correct the current command value according to an output of the position detecting portion.