Turning control device and method and program for the same

• US 20050240332A1
• Filed: 04/21/2005
• Published: 10/27/2005
• Est. Priority Date: 04/27/2004
• Status: Active Grant

• Current Assignee: Advics Company Limited (Aisin Corp.)
• Original Assignee: Advics Company Limited (Aisin Corp.)
• Inventors: Mori, Yukio, Matsuura, Masahiro, Kamiya, Kazuhiro, Kato, Kazutaka
• Granted Patent: US 7,529,600 B2
• Time in Patent Office: Days
• US Class Current: 701/72
• CPC Class Codes: B60T 2201/10 Automatic or semi-automatic parking aid systems
• CPC Class Codes: B60T 2201/16 Curve braking control, e.g. turn control within ABS control algorithm
• CPC Class Codes: B60T 2270/303 Stability control with active acceleration
• CPC Class Codes: B60T 8/1755 Brake regulation specially adapted to control the stability of the vehicle, e.g. taking into account yaw rate or transverse acceleration in a curve road vehicle drive control systems for control of driving stability otherwise than by controlling a particular sub-unit B60W30/02

Abstract

A target vehicle path is corrected in accordance with the environment surrounding a vehicle during parking assist or U-turn assist. To achieve the target vehicle path, target wheel speeds are set for respective wheels so as to generate a speed difference an inside wheel and an outside wheel of a turn. The target wheel speed is achieved by controlling braking force and driving force of each wheel. Thus, it is possible for the vehicle to turn with a smaller turning radius than that generated by a normal steering angle, and to cause the vehicle to move accurately along the target vehicle path that avoids any obstacles that are present.

Claims

1. A turning control device comprising:

a wheel speed detection portion for detecting a wheel speed of a wheel of a vehicle;

a vehicle speed detection portion for detecting a speed of the vehicle;

a turning operation detection portion for detecting whether the vehicle is in a turning operation state;

a low speed turn determination portion for determining whether turning control needs to be performed when the vehicle is in the turning operation state while running at a low speed less than a predetermined value;

a target wheel speed setting portion for setting a target wheel speed of the wheel such that the vehicle is caused to move along a desired turning path; and

a braking force control portion for controlling braking force applied to the wheel such that, when it is determined that the turning control needs to be performed, the wheel speed is caused to converge on the set target wheel speed.

2. The turning control device according to claim 1, further comprising:

a driving force control portion for controlling driving force of the vehicle such that the wheel speed converges on the target wheel speed.

3. The turning control device according to claim 2, wherein

when a wheel at the outside of a turn of the vehicle is taken as a reference wheel, the driving force control portion controls the driving force of the vehicle in accordance with a wheel speed of the reference wheel, and a target wheel speed of the reference wheel.

4. The turning control device according to claim 1, wherein

the target wheel speed setting portion causes there to be a speed difference between respective left and right target wheel speeds of, at least one of, a left and right pair of front wheels, and a left and right pair of rear wheels.

5. The turning control device according to claim 1, further comprising:

a target path setting portion for setting a target vehicle path of the vehicle, wherein

the target wheel speed setting portion sets the target wheel speed in accordance with the set target vehicle path.

6. The turning control device according to claim 5, further comprising:

a surrounding environment detection unit that detects a surrounding environment of the vehicle, wherein

the target path setting portion sets the target vehicle path in accordance with the detected surrounding environment.

7. The turning control device according to claim 5, further comprising:

a path deviation calculation portion that calculates a deviation between a projected actual path of the vehicle and the target vehicle path, and, when the deviation exceeds a pre-set determined value, terminates operation of the braking force control portion.

8. A turning control method, comprising the steps of:

detecting a wheel speed of a wheel of a vehicle;

detecting a speed of the vehicle;

determining whether the vehicle is in a turning operation state;

determining whether turning control needs to be performed when the vehicle is in the turning operation state while running at low speed;

setting a target wheel speed of the wheel such that the vehicle is caused to move along a desired turning path; and

controlling braking force applied to the wheel such that, when it is determined that the turning control needs to be performed, the braking force is controlled in accordance with the wheel speed and the set target wheel speed.

9. A turning control program for directing a computer, wherein the computer is caused to function as:

a signal reading portion for reading a detection signal from a vehicle speed detection portion for detecting a wheel speed of a wheel of a vehicle;

a vehicle speed detection portion for detecting a speed of the vehicle;

a turning operation detection portion for detecting whether the vehicle is in a turning operation state;

a low speed turn determination portion for determining whether turning control needs to be performed when the vehicle is in the turning operation state while running at a low speed less than a predetermined value;

a target wheel speed setting portion for setting a target wheel speed of the wheel such that the vehicle is caused to move along a desired turning path; and

a braking force control portion for controlling braking force applied to the wheel such that, when it is determined that the turning control needs to be performed, the wheel speed is caused to converge on the set target wheel speed.