Steering control device

Patent metadata

Field	Value
Publication number	US-9399486-B2
Application number	US-201314429014-A
Country	US
Kind code	B2
Filing date	Sep 11, 2013
Priority date	Sep 25, 2012
Publication date	Jul 26, 2016
Grant date	Jul 26, 2016

Abstract

The turning amount of a turning unit is controlled according to the steering amount of a steering unit mechanically uncoupled from the turning unit. A steering reaction force characteristic in which the larger the self-aligning torque, the larger the steering reaction force is set on coordinates with the self-aligning torque and the steering reaction force as coordinate axes. When the steering reaction force corresponding to the self-aligning torque is applied to the steering unit based on the steering reaction force characteristic, the steering reaction force characteristic is offset on the coordinates in such a direction that the closer the lateral position of an own vehicle to a white line, the larger the absolute value of the steering reaction force.

First claim

The invention claimed is:

1. A steering control device comprising:
a steering wheel configured to receive steering input from a driver;
a steering gear mechanically uncoupled from the steering wheel and configured to turn a turning wheel;
a sensor configured to detect a lateral position of an own vehicle relative to a white line; and
a controller configured to control a turning amount of the steering gear based on a steering amount of the steering wheel, to set a steering characteristic such that a steering torque increases in accordance with an increase of a steering angle, and to offset the steering characteristic in such a direction that the closer the detected lateral position to the white line, the larger an absolute value of a steering reaction force, when applying the steering reaction force to the steering wheel based on the steering characteristic.

2. The steering control device according to claim 1 , wherein the steering characteristic is that a sign of the steering reaction force is inverted over a position where a self-aligning torque is zero.

3. The steering control device according to claim 1 , wherein the controller is further configured to:
calculate margin time that is time required for the own vehicle to reach the white line,
calculate a lateral position offset amount such that the lateral position offset amount becomes larger as the detected lateral position becomes closer to the white line,
calculate a margin time offset amount such that the margin time offset amount becomes larger as the calculated margin time becomes shorter, and
perform offset using the larger offset amount between the lateral position offset amount and the margin time offset amount.

4. A steering control device comprising:
a steering wheel configured to receive steering input from a driver;
a steering gear mechanically coupled to the steering wheel and configured to turn a turning wheel;
a sensor configured to detect a lateral position of an own vehicle relative to a white line; and
a controller configured to set an assist torque characteristic such that the larger a steering torque, the larger an assist torque, on coordinates with the steering torque and the assist torque as coordinate axes, and to offset the assist torque characteristic on the coordinates in such a direction that the closer the detected lateral position to the white line, the smaller an absolute value of the assist torque, when applying the assist torque corresponding to the steering torque to the steering gear based on the assist torque characteristic.

5. The steering control device according to claim 4 , wherein the assist torque characteristic is that a sign of the assist torque is inverted over a position where the steering torque is zero.

6. The steering control device according to claim 4 , wherein the controller is further configured to:
calculate margin time that is time required for the own vehicle to reach the white line,
calculate a lateral position offset amount such that the lateral position offset amount becomes larger as the detected lateral position becomes closer to the white line,
calculate a margin time offset amount such that the margin time offset amount becomes larger as the calculated margin time becomes shorter, and
perform the offset using the larger offset amount between the lateral position offset amount and the margin time offset amount.

7. A steering control method comprising:
controlling a turning amount of a steering gear according to a steering amount of a steering wheel mechanically uncoupled from the steering gear;
setting a steering reaction force characteristic such that the larger a self-aligning torque, the larger a steering reaction force, on coordinates with the self-aligning torque and the steering reaction force as coordinate axes; and
offsetting the steering reaction force characteristic on the coordinates in such a direction that the closer the lateral position of an own vehicle to a white line, the larger an absolute value of the steering reaction force, when applying the steering reaction force corresponding to the self-aligning torque to the steering wheel based on the steering reaction force characteristic.

8. A steering control device comprising:
a sensor configured to detect a lateral position of an own vehicle relative to a white line; and
a controller configured to control a turning amount of a turning unit according to a steering amount of a steering unit mechanically uncoupled from the turning unit, to set a steering reaction force characteristic such that the larger a self-aligning torque, the larger a steering reaction force, on coordinates with the self-aligning torque and the steering reaction force as coordinate axes, and to offset the steering reaction force characteristic on the coordinates in such a direction that the closer the detected lateral position of the own vehicle to the white line, the larger an absolute value of the steering reaction force, when applying the steering reaction force corresponding to the self-aligning torque to the steering unit based on the steering reaction force characteristic.

9. A steering control method comprising:
setting an assist torque characteristic such that the larger a steering torque, the larger an assist torque, on coordinates with the steering torque and the assist torque as coordinate axes; and
offsetting the assist torque characteristic on the coordinates in such a direction that the closer a lateral position of an own vehicle to a white line, the smaller an absolute value of the steering torque, when applying the assist torque corresponding to the steering torque to a steering wheel mechanically coupled to a steering gear based on the assist torque characteristic.

10. A steering control device comprising:
a sensor configured to detect a lateral position of an own vehicle relative to a white line; and
a controller configured to set an assist torque characteristic such that the larger a steering torque, the larger an assist torque, on coordinates with the steering torque and the assist torque as coordinate axes, and to offset the assist torque characteristic on the coordinates in such a direction that the closer the detected lateral position of the own vehicle to the white line, the smaller an absolute value of the steering torque, when applying the assist torque corresponding to the steering torque to a steering unit mechanically coupled to a turning unit based on the assist torque characteristic.

Assignees

• Nissan Motor

Inventors

• Takeda Yuya

Classifications

• B62D15/025 Primary

  Active steering aids, e.g. helping the driver by actively influencing the steering system after environment evaluation (B62D1/28 takes precedence) · CPC title

• B62D6/008 Primary

  Control of feed-back to the steering input member, e.g. simulating road feel in steer-by-wire applications · CPC title

• B62D6/003

  in order to control vehicle yaw movement, i.e. around a vertical axis (B62D6/007 takes precedence) · CPC title

• B62D15/021

  Determination of steering angle · CPC title

• G06K9/00798

  Physics · mapped topic