Vehicle steering control system

• US 6,308,123 B1
• Filed: 06/23/2000
• Issued: 10/23/2001
• Est. Priority Date: 06/25/1999
• Status: Expired due to Term

• Current Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Original Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Inventors: Ikegaya, Manabu, Tanaka, Jun, Kondo, Satoshi, Ishida, Shinnosuke
• Primary Examiner(s): Chin, Gary
• Application Number:
  US09/599,606
• Time in Patent Office: 487 Days
• Field of Search: 701/41, 701/42, 701/43, 180/410, 180/412, 180/415, 180/422, 180/443, 180/446
• US Class Current: 701/41
• CPC Class Codes: B60T 2201/08 Lane monitoring; Lane Keeping Systems
• CPC Class Codes: B60T 2201/087 using active steering actuation
• CPC Class Codes: B62D 1/28 non-mechanical , e.g. following a line or other known markers
• CPC Class Codes: B62D 15/025 Active steering aids, e.g. helping the driver by actively influencing the steering system after environment evaluation B62D1/28 takes precedence

Abstract

A vehicle steering control system for conducting a steering assistance control in which a basic steering assist torque is determined based on a structural parameter relating to the lane structure such as its curvature. In parallel, corrective steering assist torques are determined based on positional parameters of the vehicle relating to the lane such as a lateral deviation from the lane center line and a vehicle heading angle, and are added to the basic steering assist torque to correct the same. Since the positional parameters are determined based on the image information at or close to the vehicle, this enables to determine the steering assist torque adequately, thereby enhancing the accuracy of the steering assistance control.

Claims

1. A system for controlling steering of a vehicle having an actuator which turns steered wheels of the vehicle;

comprising;

an image sensor mounted on the vehicle for taking an image ahead of the vehicle;

lane detecting means for detecting a lane on which the vehicle travels based on image information obtained from outputs of the image sensor;

basic steering assist torque determining means for determining a structural parameter relating to a structure of the detected lane and for determining a basic steering assist torque based on the determined structural parameter in accordance with a predetermined characteristic;

corrective steering assist torque determining means for determining a positional parameter of the vehicle relating to the lane and for calculating a corrective steering assist torque based on the determined positional parameter;

actuator manipulated variable determining means for determining a manipulated variable to be supplied to the actuator based on the determined basic steering assist torque and the corrective steering assist torque such that the vehicle runs along the lane; and

an actuator driver for driving the actuator based on the determined manipulated variable.

2. A system according to claim 1, wherein the corrective steering assist torque determining means includes:

vehicle position determining means for determining a position of the vehicle on the lane based on the image information;

error determining means for determining an error between the detected position of the vehicle and a desired value as the positional parameter; and

corrective steering assist torque calculating means for calculating the corrective steering assist torque by multiplying the determined error by a feedback correction coefficient.

3. A system according to claim 1, wherein the positional parameter is at least one of a lateral deviation of the vehicle in a vehicle-width direction from a reference line of the lane and a heading angle of the vehicle relative to the lane.

4. A system according to claim 1, wherein the corrective steering assist torque determining means includes:

vehicle position determining means for determining a position of the vehicle on the lane based on the image information;

vehicle heading angle calculating means for calculating a heading angle of the vehicle relative to the lane based on the detected position of the vehicle as the positional parameter; and

corrective steering assist torque calculating means for calculating the corrective steering assist torque by multiplying the calculated heading angle of the vehicle by a feedback correction coefficient.

5. A system according to claim 4, wherein the corrective steering assist torque determining means includes:

heading angle differential calculating means for calculating a differential of the calculated heading angle of the vehicle; and

corrective steering assist torque calculating means for calculating the corrective steering assist torque by multiplying the calculated differential of the heading angle of the vehicle by a feedback correction coefficient.