VARIABLE REAR WHEEL TOE ANGLE CONTROL SYSTEM FOR A VEHICLE

• US 20080054577A1
• Filed: 07/31/2007
• Published: 03/06/2008
• Est. Priority Date: 08/29/2006
• Status: Active Grant

• Current Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Original Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Inventors: Horiuchi, Yutaka
• Granted Patent: US 7,516,965 B2
• Time in Patent Office: Days
• US Class Current: 280/5.522
• CPC Class Codes: B60T 2260/06 Active Suspension System
• CPC Class Codes: B62D 17/00 Means on vehicles for adjusting camber, castor, or toe-in
• CPC Class Codes: B62D 6/02 responsive only to vehicle speed

Abstract

A variable rear wheel toe angle control system for a vehicle that can appropriately control a rear wheel toe angle without detecting a turning movement of the vehicle. Because the rear wheel toe angle can be appropriately controlled according to acceleration/deceleration of the vehicle, the turning and straight traveling performance of the vehicle can be improved. In particular, if the acceleration is computed from an output of an accelerator pedal sensor and/or an output of the brake pedal sensor, the response delay is minimized, and a favorable handling of the vehicle can be achieved. Also, the variable toe angle control may be used for favorably compensating for the change in the toe angle owing to the tendency of the vehicle to nose lift in acceleration and nose dive in deceleration caused by geometry of a rear suspension system, thereby enhancing freedom in design of the rear suspension system.

Claims

1. A variable rear wheel toe angle control system for a vehicle, comprising:

an accelerator pedal for accelerating the vehicle;

a brake pedal for decelerating the vehicle;

an actuator for varying a toe angle of each rear wheel; and

a control unit for activating the actuator according to an operating condition of the vehicle;

wherein the operating condition of the vehicle comprises a fore-and-aft acceleration of the vehicle.

2. The variable rear wheel toe angle control system according to claim 1, further comprising an accelerator pedal sensor for detecting a pedal displacement of the accelerator pedal, the fore-and-aft acceleration is computed from an output of the accelerator pedal sensor.

3. The variable rear wheel toe angle control system according to claim 1, further comprising a brake pedal sensor for detecting a pedal displacement of the brake pedal, the fore-and-aft acceleration is computed from an output of the brake pedal sensor.

4. The variable rear wheel toe angle control system according to claim 2, further comprising a fore-and-aft acceleration sensor for detecting a fore-and-aft acceleration of the vehicle, the fore-and-aft acceleration for the operating condition is computed from both an output of the accelerator pedal sensor and an output of the fore-and-aft acceleration sensor.

5. The variable rear wheel toe angle control system according to claim 3, further comprising a fore-and-aft acceleration sensor for detecting a fore-and-aft acceleration of the vehicle, the fore-and-aft acceleration for the operating condition is computed from both an output of the brake pedal sensor and an output of the fore-and-aft acceleration sensor.

6. The variable rear wheel toe angle control system according to claim 1, further comprising a variable roll stiffness control system, the operating condition further including an operating condition of the variable roll stiffness control system.

7. The variable rear wheel toe angle control system according to claim 1, wherein the control unit is configured to provide a slight toe-in when there is no acceleration and actuate the actuator in a toe-out direction with an increasing acceleration.

8. A variable rear wheel toe angle control method for a vehicle, comprising:

preparing an actuator for varying a toe angle of each rear wheel;

detecting a fore-and-aft acceleration of the vehicle; and

actuating the actuator in dependence on the fore-and-aft acceleration of the vehicle.

9. The variable rear wheel toe angle control method for a vehicle according to claim 8, further comprising:

preparing an accelerator pedal sensor for detecting a displacement of an accelerator pedal and computing the fore-and-aft acceleration of the vehicle from an output of the accelerator pedal sensor.

10. The variable rear wheel toe angle control method for a vehicle according to claim 8, further comprising:

preparing a brake pedal sensor for detecting a displacement of a brake pedal and computing the fore-and-aft acceleration of the vehicle from an output of the brake pedal sensor.

11. The variable rear wheel toe angle control method for a vehicle according to claim 8, further comprising:

preparing an accelerator pedal sensor for detecting a displacement of an accelerator pedal, preparing a fore-and-aft acceleration sensor for detecting a fore-and-aft acceleration of the vehicle, and computing the fore-and-aft acceleration of the vehicle from both an output of the accelerator pedal sensor and an output of the acceleration sensor.

12. The variable rear wheel toe angle control method for a vehicle according to claim 8, further comprising:

detecting an operating condition of a variable roll stiffness control system, and taking into account the detected operating condition of the variable roll stiffness control system when actuating the actuator.

13. The variable rear wheel toe angle control method for a vehicle according to claim 8, wherein the actuator is actuated in such a manner that a slight toe-in is achieved when there is no acceleration and the actuator is actuated progressively in a toe-out direction with an increasing acceleration.