Vehicle controller and noise reducing method of differential gear

A vehicle controller for reducing noise of a differential gear of a vehicle, the vehicle including:

• a ring gear teeth-engaged with a motor reducer, a differential case connected to the ring gear, a differential assembly including differential gears disposed inside the differential case, and a disconnector device connected to at least one of the differential gears, the vehicle controller comprising:
• an RPM measuring unit configured to measure a rotational speed of one vehicle wheel when the vehicle is being driven in a two-wheel drive mode;
• a speed calculation unit configured to calculate a rotational speed of the ring gear based on the rotational speed of the one vehicle wheel;
• and
• a driving unit configured to drive the ring gear by controlling the motor reducer based on the rotational speed of the ring gear,
• wherein the driving unit is configured to, by rotational driving of the ring gear, reduce a number of relative revolutions between a first side gear of the differential gear connected to the one vehicle wheel and disposed inside the differential case and a second side gear of the differential gear connected to the disconnector device and disposed inside the differential case when the vehicle is being driven in the two-wheel drive mode,
• wherein the driving unit is configured to reduce the number of relative revolutions between the first side gear and second side gear by two times a number of revolutions of the ring gear per unit of time when the ring gear rotates.