Abstract: A rotation angle correction device corrects a rotation angle of a converter converting a signal from a resolver attached to a motor. An arrival time measurement unit measures an arrival time at which the rotation angle reaches a specified rotation angle from a reference angle in a current cycle. A reference time calculation unit calculates a reference time at which the rotation angle reaches the specified rotation angle from the reference angle assuming that the motor rotates in the current cycle at the same angular velocity as an angular velocity in a previous cycle. A difference calculation unit calculates a difference between the arrival time and the reference time. An error angle calculation unit multiplies the difference between the arrival time and the reference time and the angular velocity in the previous cycle to obtain an error angle. A correction unit corrects the rotation angle based on the error angle.

Abstract: A rotation angle correction device corrects a rotation angle of a converter converting a signal from a resolver attached to a motor. An arrival time measurement unit measures an arrival time at which the rotation angle reaches a specified rotation angle from a reference angle in a current cycle. A reference time calculation unit calculates a reference time at which the rotation angle reaches the specified rotation angle from the reference angle assuming that the motor rotates in the current cycle at the same angular velocity as an angular velocity in a previous cycle. A difference calculation unit calculates a difference between the arrival time and the reference time. An error angle calculation unit multiplies the difference between the arrival time and the reference time and the angular velocity in the previous cycle to obtain an error angle. A correction unit corrects the rotation angle based on the error angle.