Steering control for drive wheels of vehicle

• US 20040238238A1
• Filed: 05/20/2004
• Published: 12/02/2004
• Est. Priority Date: 05/26/2003
• Status: Active Grant

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Yokote, Masatsugu
• Granted Patent: US 7,360,614 B2
• Time in Patent Office: Days
• US Class Current: 180/6.2
• CPC Class Codes: B60L 15/2036 Electric differentials, e.g. for supporting steering vehicles
• CPC Class Codes: B62D 5/0472 for damping vibrations
• CPC Class Codes: B62D 6/008 Control of feed-back to the steering input member, e.g. simulating road feel in steer-by-wire applications
• CPC Class Codes: B62D 9/002 combined with means for differentially distributing power on the deflectable wheels during cornering
• CPC Class Codes: Y02T 10/64 Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/72 Electric energy management in electromobility

Abstract

In a vehicle, a pair of left and right drive wheels are linked with a steering input device so that the drive wheels are turned in accordance with a driver'"'"'s steering input force input by a driver to the steering input device. In this course, a steering assistance force is added to the driver'"'"'s steering input force. Driving forces to be applied to the drive wheels are individually controlled in accordance with a running condition of the vehicle. A steering reaction force is calculated which originates from a difference in the driving forces between the drive wheels and acts on the steering input device. The steering assistance force added to the driver'"'"'s steering input force is increased or decreased so as to compensate the steering reaction force.

Claims

1. A steering apparatus for controlling left and right drive wheels of a vehicle, comprising:

a driving force control section to control left and right driving forces of the left and right drive wheels individually in accordance with a running condition of the vehicle;

a power assistance device to add a steering assistance force to a driver'"'"'s steering input force input to a steering input device;

a steering mechanism to link the left and right drive wheels with the steering input device so that the left and right drive wheels are turned in accordance with the driver'"'"'s steering input force and the steering assistance force added thereto;

a steering reaction force calculating section to calculate a steering reaction force acting on the steering input device in accordance with a difference between the left and right driving forces; and

a steering force correcting section to correct the steering assistance force so as to compensate the steering reaction force.

2. The steering apparatus as claimed in claim 1, wherein the steering force correcting section decreases the steering assistance force when the driving force control section increases the driving force of an outer drive wheel of the drive wheels outside of a turning radius of the vehicle.

3. The steering apparatus as claimed in claim 1, wherein the steering force correcting section increases the steering assistance force when the driving force control section decreases the driving force of an outer drive wheel of the drive wheels outside of a turning radius of the vehicle.

4. The steering apparatus as claimed in claim 1, wherein the steering force correcting section increases the steering assistance force when the driving force control section increases the driving force of an inner drive wheel of the drive wheels inside of a turning radius of the vehicle.

5. The steering apparatus as claimed in claim 1, wherein the steering force correcting section decreases the steering assistance force when the driving force control section decreases the driving force of an inner drive wheel of the drive wheels inside of a turning radius of the vehicle.

6. The steering apparatus as claimed in claim 1, wherein the steering force correcting section corrects a magnitude of the steering assistance force so as to compensate the steering reaction force when the driving force control section corrects a magnitude of the driving force of one of the left and right drive wheels when the vehicle is running substantially straight.

7. The steering apparatus as claimed in claim 1, wherein the steering force correcting section corrects a magnitude of the steering assistance force so as to compensate the steering reaction force when the driving force control section corrects a magnitude of the driving force of at least one of the left and right drive wheels in accordance with a running environment of the vehicle.

8. A steering process for controlling left and right steerable drive wheels of a vehicle, comprising:

examining a difference between left and right driving forces individually controlled for the left and right drive wheels turned in accordance with a driver'"'"'s steering input force input to a steering input device and a steering assistance force added to the driver'"'"'s steering input force; and

varying the steering assistance force so as to compensate a steering reaction force acting on the steering input device in accordance with the difference between the left and right driving forces.

9. A steering apparatus for controlling left and right steerable drive wheels of a vehicle, comprising:

means for controlling left and right driving forces of the left and right drive wheels individually in accordance with a running condition of the vehicle;

means for calculating a steering reaction force acting on the steering input device in accordance with a left and right driving force difference between the left and right driving forces; and

means for varying a steering assistance force so as to compensate the steering reaction force.