Motor Control Apparatus and Motor Control Method

A motor control apparatus that rotates a rotor of an electric motor by sequentially switching an energization mode that determines two-phase coils to which a pulse voltage is applied, among three-phase coils of the electric motor, the motor control apparatus comprising a computer,

• wherein the computer is configured to
• output a control signal to a drive circuit that drives the electric motor such that the pulse voltage alternately generates a first pulse that rotates the rotor in one direction and a second pulse that has a polarity opposite to a polarity of the first pulse and that rotates the rotor in a direction opposite to the one direction, and control rotation drive in the one direction or the opposite direction by inverting a comparative relationship between an application time of the first pulse and an application time of the second pulse,
• detect a first open-phase voltage induced in an open phase when the first pulse is applied, and detect a second open-phase voltage induced in an open phase when the second pulse is applied,
• set, per energization mode, a first threshold that defines a value of the first open-phase voltage when the energization mode is switched to the one direction, and a second threshold that defines a value of the second open-phase voltage when the energization mode is switched to the opposite direction, and
• switch the energization mode to the one direction or the opposite direction, based on a result of comparison between a value of the first open-phase voltage and the first threshold and based on a result of comparison between a value of the second open-phase voltage and the second threshold,
• wherein when the energization mode is switched to the opposite direction, the computer sets, as a threshold setting process, the first threshold based on a first switching time detection value, which is a value of the first open-phase voltage immediately after the switching of the energization mode, and based on a first initial threshold that is set in advance per energization mode, and
• wherein when the energization mode is switched to the one direction, the computer sets, as the threshold setting process, the second threshold based on a second switching time detection value, which is a value of the second open-phase voltage immediately after the switching of the energization mode, and based on a second initial threshold that is set in advance per energization mode.