Left-right wheel drive force distribution control apparatus for a vehicle

• US 8,775,045 B2
• Filed: 07/05/2011
• Issued: 07/08/2014
• Est. Priority Date: 07/09/2010
• Status: Active Grant

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Tsushima, Yohei
• Primary Examiner(s): Tarcza, Thomas
• Assistant Examiner(s): PIPALA, EDWARD J
• Application Number:
  US13/700,359
• Publication Number:
  US 20130073161A1
• Time in Patent Office: 1,099 Days
• Field of Search: 701/1, 701/51, 701/53, 701/58, 701/60, 701/65, 701/67, 701/68, 701/69, 701/70, 701/71, 701/72, 701/74, 701/76, 701/77, 701/78, 701/80, 701/81, 701/82, 701/88, 701/89, 701/90, 180/170, 180/197, 180/271, 180/282, 340/438, 340/439, 340/440, 340/441
• 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 execute a distributed output of drive forces to left and right drive wheels in accordance with a left-right 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 three 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.