VEHICLE WITH A VARIABLE REAR TOE ANGLE

• US 20090177348A1
• Filed: 01/07/2009
• Published: 07/09/2009
• Est. Priority Date: 01/08/2008
• Status: Active Grant

• Current Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Original Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Inventors: Yanagi, Takashi
• Granted Patent: US 8,068,955 B2
• Time in Patent Office: Days
• US Class Current: 701/29
• CPC Class Codes: B62D 7/148 provided with safety devices

Abstract

In a vehicle provided with a rear wheel toe angle varying device for individually varying toe angles of rear wheels, upon detection of a failure to steer one of the rear wheels, the rear wheel of a healthy side is steered in a direction to enable the vehicle to travel straight ahead. Preferably, a control unit of the rear wheel toe angle varying device steers the rear wheel of a healthy side in parallel to the rear wheel of the faulty side, and the vehicle is enabled to travel straight ahead even though the traveling direction of the vehicle is at a certain angle with respect to the longitudinal line of the vehicle body. At this time, front wheels are typically steered at the same angle as the rear wheels. The device may further comprise a toe angle estimating unit.

Claims

1. A vehicle provided with a rear wheel toe angle varying device for individually varying toe angles of rear wheels, the rear wheel toe angle varying device comprising:

a pair of drive units for steering the rear wheels;

at least one sensor for detecting a status of the vehicle;

a control unit for controlling the drive units according to an output of the sensor; and

a monitoring unit for detecting a failure to steer each rear wheel as controlled by the control unit;

wherein the control unit is configured such that, upon detection of a failure to steer each rear wheel, the rear wheel of a healthy side is steered in a direction to enable the vehicle to travel straight ahead.

2. The vehicle provided with a rear wheel toe angle varying device according to claim 1, wherein the monitoring unit for detecting a failure to steer each rear wheel is configured to detect a fault in a stroke sensor that detects an actual steered angle of the corresponding rear wheel.

3. The vehicle provided with a rear wheel toe angle varying device according to claim 1, wherein the monitoring unit for detecting a failure to steer each rear wheel is configured to detect a fault in a power actuator for steering each rear wheel.

4. The vehicle provided with a rear wheel toe angle varying device according to claim 1, wherein the monitoring unit for detecting a failure to steer each rear wheel is configured to detect a fault in a part of the control unit responsible for steering each rear wheel.

5. The vehicle provided with a rear wheel toe angle varying device according to claim 1, wherein upon occurrence of a failure to steer one of the rear wheels, the control unit steers the rear wheel of the healthy side in parallel to the rear wheel of a faulty side.

6. The vehicle provided with a rear wheel toe angle varying device according to claim 1, wherein upon occurrence of a failure to steer one of the rear wheels, the control unit steers the rear wheel of the healthy side by a same angle in an opposite direction in relation to the rear wheel of a faulty side.

7. The vehicle provided with a rear wheel toe angle varying device according to claim 1, wherein the rear wheel toe angle varying device further comprises a steering angle sensor for detecting a steering angle of front wheels, a straight travel determining unit for determining that the vehicle is traveling straight ahead, and a toe angle estimating unit that, occurrence of a failure to steer one of the rear wheels, steers the rear wheel of the healthy side to a zero angle, and estimates a steering angle of the rear wheel of a faulty side from the steering angle of the front wheels when the vehicle is traveling straight ahead.

8. The vehicle provided with a rear wheel toe angle varying device according to claim 7, wherein the toe angle estimating unit estimates the steering angle of the rear wheel of the faulty side to be one half of the steering angle of the front wheels.