VEHICLE BEHAVIOR CONTROL SYSTEM

• US 20100211261A1
• Filed: 02/12/2010
• Published: 08/19/2010
• Est. Priority Date: 02/10/2009
• Status: Abandoned Application

• Current Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Original Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Inventors: Sasaki, Hitoshi, Nishimori, Takashi, Kaji, Toshimitsu, Tsujioka, Takashi, Hara, Tetsuro, SASAKI, Hiroaki
• Application Number:
  US12/705,316
• Publication Number:
  US 20100211261A1
• Time in Patent Office: Days
• US Class Current: 701/37
• CPC Class Codes: B60G 17/016 characterised by their responsiveness, when the vehicle is travelling, to specific motion, a specific condition, or driver input B60G17/017 takes precedence
• CPC Class Codes: B60G 17/018 characterised by the use of a specific signal treatment or control method
• CPC Class Codes: B60G 17/0195 characterised by the regulation being combined with other vehicle control systems conjoint control of vehicle sub-units including control of suspension systems B60W10/22
• CPC Class Codes: B60G 17/08 Characteristics of fluid dampers adjusting fluid dampers in general F16F9/44 - F16F9/53
• CPC Class Codes: B60G 2200/44 steerable
• CPC Class Codes: B60G 2202/24 Fluid damper
• CPC Class Codes: B60G 2204/62 Adjustable continuously, e.g. during driving
• CPC Class Codes: B60G 2400/0523 Yaw rate
• CPC Class Codes: B60G 2400/102 vertical
• CPC Class Codes: B60G 2400/104 lateral or transversal with regard to vehicle
• CPC Class Codes: B60G 2400/106 longitudinal with regard to vehicle, e.g. braking
• CPC Class Codes: B60G 2400/204 Vehicle speed
• CPC Class Codes: B60G 2400/252 vertical
• CPC Class Codes: B60G 2400/41 Steering angle
• CPC Class Codes: B60G 2400/46 Steering frequency
• CPC Class Codes: B60G 2400/47 Rear wheel steering
• CPC Class Codes: B60G 2400/61 Load distribution
• CPC Class Codes: B60G 2500/104 continuous
• CPC Class Codes: B60G 2500/11 Damping valves
• CPC Class Codes: B60G 2600/184 Semi-Active control means
• CPC Class Codes: B60G 2600/70 : Computer memory; Data storage, e.g. maps for adaptive control
• CPC Class Codes: B60G 2800/012 : Rolling condition
• CPC Class Codes: B60G 2800/0122 : Roll rigidity ratio; Warping
• CPC Class Codes: B60G 2800/014 : Pitch; Nose dive
• CPC Class Codes: B60G 2800/214 : by varying the load distribution
• CPC Class Codes: B60G 2800/24 : Steering, cornering
• CPC Class Codes: B60G 2800/91 : Suspension Control
• CPC Class Codes: B60G 2800/914 : Height Control System
• CPC Class Codes: B60G 2800/962 : Four-wheel steering
• CPC Class Codes: B60W 30/045 : Improving turning performance
• CPC Class Codes: B60W 40/11 : Pitch movement
• CPC Class Codes: B60W 40/112 : Roll movement
• CPC Class Codes: B60W 40/114 : Yaw movement

Abstract

Provide is a vehicle behavior control system that can achieve a rear wheel steering control demonstrating a high rate of response at all times without requiring the actuator for the rear wheels to be steered to be unduly increased. A control unit (20) for controlling the rear wheel steering angle is configured to reduce the effective stiffness of the rear wheel suspension systems while increasing the effective stiffness of the front wheel suspension systems when an increase in the road contact load of one of the rear wheels is detected or estimated. Thereby, an actuator (8) for the rear wheel is enabled to steering the rear wheels without involving any undue time delay with a minimum power requirement.

Claims

1. A vehicle behavior control system for a vehicle including a pair of front wheels configured to be steered by a vehicle operator and a pair of rear wheels configured to be steered by a steering actuator, comprising:

a wheel suspension system supporting each wheel, the wheel suspension system including a variable wheel suspension element that can change an effective stiffness of the corresponding wheel suspension system;

a first sensor for detecting an operating condition of the vehicle;

a second sensor for detecting an increase in a road contact load of each rear wheel; and

a control unit that actuates the steering actuator according to an operating condition of the vehicle detected by the first sensor;

wherein the control unit is configured to reduce the effective stiffness of the variable wheel suspension element corresponding to at least one of the rear wheels in relation to the effective stiffness of the variable wheel suspension elements corresponding to the front wheels when the second sensor has detected an increase in the road contact load of one of the rear wheels.

5. The vehicle behavior control system according to claim 1, wherein the increasing and decreasing of the effective stiffness of the variable suspension elements by the control unit is allowed only when a deviation of an actual rear wheel steering angle of the one rear wheel effected by the actuator from a target rear steering angle commanded by the control unit is greater than a prescribed value.

6. The vehicle behavior control system according to claim 1, wherein the increasing and decreasing of the effective stiffness of the variable suspension elements by the control unit is allowed only when a deviation of an actual rear wheel steering angle of the one rear wheel effected by the actuator from a target rear steering angle commanded by the control unit is greater than a prescribed value and a lateral acceleration of the vehicle is greater than a prescribed value.

7. The vehicle behavior control system according to claim 1, wherein the variable wheel suspension element comprises a variable damping force damper.

8. The vehicle behavior control system according to claim 1, wherein the variable wheel suspension element comprises an active wheel suspension element.

2. The vehicle behavior control system according to claim I, wherein the control unit reduces the effective stiffness of the variable wheel suspension elements corresponding both the rear wheels when the second sensor has detected an increase in the road contact load of one of the rear wheels.

3. The vehicle behavior control system according to claim 2, wherein the control unit increases the effective stiffness of the variable wheel suspension elements corresponding the front wheels at the same time as decreasing the effective stiffness of the variable wheel suspension elements corresponding the rear wheels when the second sensor has detected an increase in the road contact load of one of the rear wheels.

4. The vehicle behavior control system according to claim 3, wherein the control unit increases the effective stiffness of the variable wheel suspension elements corresponding the front wheels and decreases the effective stiffness of the variable wheel suspension elements corresponding the rear wheels when the second sensor has detected an increase in the road contact load of one of the rear wheels owing to a cornering movement of the vehicle such that a roll angle of the vehicle remains substantially unchanged by the increasing and decreasing of the effective stiffness of the variable suspension elements.