LEFT-RIGHT WHEEL DRIVE FORCE DISTRIBUTION CONTROL APPARATUS FOR A VEHICLE

• US 20130073161A1
• Filed: 07/05/2011
• Published: 03/21/2013
• Est. Priority Date: 07/09/2010
• Status: Active Grant

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Tsushima, Yohei
• Granted Patent: US 8,775,045 B2
• Time in Patent Office: Days
• US Class Current: 701/69
• CPC Class Codes: B60K 17/344 having a transfer gear
• CPC Class Codes: B60K 2023/043 Control means for varying left-right torque distribution, e.g. torque vectoring
• CPC Class Codes: B60K 23/0808 for varying torque distribution between driven axles, e.g. by transfer clutch
• CPC Class Codes: B60W 10/119 including control of all-wheel-driveline means, e.g. transfer gears or clutches for dividing torque between front and rear axle B60W10/14 takes precedence
• CPC Class Codes: B60W 10/16 Axle differentials, e.g. for dividing torque between left and right wheels
• CPC Class Codes: B60W 2720/28 Wheel speed
• CPC Class Codes: B60W 2720/403 between front and rear axle
• CPC Class Codes: B60W 2720/406 between left and right wheel
• CPC Class Codes: B60W 30/045 Improving turning performance
• CPC Class Codes: F16H 2048/205 using the steering as a control parameter
• CPC Class Codes: F16H 48/19 consisting of two linked clutches

Abstract

A rear wheel drive force difference setting gain is multiplied by a basic left-right rear wheel drive force difference steady-state control computation value for achieving a vehicle turning behavior steadily requested by a driver in order to calculate a final left-right rear wheel drive force difference steady-state control amount. The final left-right rear wheel drive force difference steady-state control amount is added to a left-right rear wheel drive force difference transient control amount to obtain left-right rear wheel rear wheel drive force difference. This difference is multiplied by feedback control coefficient to obtain a final rear wheel drive force difference. During an initial stage of turning in which a lateral acceleration is smaller than a turn initial stage determining value, the rear wheel drive force difference setting gain is set to A, which is larger than 1 and increases as the lateral acceleration decreases. As a result, the final rear wheel drive force difference is increased during the initial stage of turning and an initial turning response can be improved.

Claims

1. A vehicle left-right wheel drive force distribution control apparatus comprising:

a controller programmed to executes a distributed output of drive forces to left and right drive wheels in accordance with a front-rear wheel drive force distribution control, the controller including

a left-right wheel drive force control section that controls the drive forces of the left and right drive wheels such that a target value of a left-right drive force difference corresponding to a targeted turning behavior of the vehicle is achieved;

a turn initial stage detecting section that detects an initial stage of a vehicle turning behavior; and

a turn initial stage left-right drive force difference increasing section that increases the target value of the left-right drive force difference during a period while the turn initial stage detecting section detects an initial stage of a turn,

the turn initial stage left-right drive force difference increasing section increasing the target value of the left-right drive force difference by multiplying the target value of the left-right drive force difference by a gain that becomes larger as the vehicle turning behavior becomes smaller while the vehicle turning behavior is in a region of the initial stage of the turn.

2. The vehicle left-right wheel drive force distribution control apparatus according to claim 1, wherein

the turn initial stage detecting section determines that the initial stage of the turn exists during a period while the vehicle turning behavior is smaller than a set value.

3. (canceled)

4. (canceled)