Vehicle control apparatus for motor noise suppression and torque control, electric vehicle, and non-transitory recording medium

A non-transitory computer readable recording medium containing a computer program to be applied to a control apparatus for an electric vehicle, the electric vehicle being configured to transmit an output torque outputted from a drive motor to a drive wheel via a transmission, the computer program causing, when executed by one or more processors, the one or more processors to implement a method, the method comprising:

• determining whether a vehicle speed of the electric vehicle is in a predetermined low vehicle speed region or a predetermined high vehicle speed region in which vehicle speeds are higher than those in the predetermined low vehicle speed region;
• when the vehicle speed of the electric vehicle is in the predetermined low vehicle speed region, (1) controlling a rotational speed of the drive motor to be less than a predetermined rotation threshold at which a frequency of a motor noise to be generated from the drive motor becomes less than a predetermined frequency, and (2) controlling a transmission ratio of the transmission, under a constraint that the rotational speed of the drive motor is controlled to be less than the predetermined rotation threshold, to cause a drive torque to be transmitted to the drive wheel to be a requested drive torque;
• and
• when the vehicle speed of the electric vehicle is in the predetermined high vehicle speed region, (1) controlling the rotational speed of the drive motor to cause an electric power efficiency of the drive motor to be equal to or higher than a predetermined efficiency, and (2) controlling the transmission ratio of the transmission to cause the drive torque to be transmitted to the drive wheel to be the requested drive torque.