Lane keeping assist device

• US 10,065,639 B2
• Filed: 04/09/2015
• Issued: 09/04/2018
• Est. Priority Date: 04/09/2015
• Status: Active Grant

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Taniguchi, Hiroki
• Primary Examiner(s): Goldman, Richard A
• Application Number:
  US15/562,938
• Publication Number:
  US 20180086341A1
• Time in Patent Office: 1,244 Days
• Field of Search: 701 41, 701 42, 180443, 180402
• CPC Class Codes: B60W 2510/205 Steering speed
• CPC Class Codes: B60W 30/12 Lane keeping
• 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
• CPC Class Codes: B62D 6/002 computing target steering angles for front or rear wheels B62D7/159 takes precedence
• 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: G01P 3/64 Devices characterised by the determination of the time taken to traverse a fixed distance

Abstract

A lane keeping assist device assists a steer-by-wire vehicle to stay in a traveling lane. The lane keeping assist device controls the turning angle of the turning wheel using a first turning angle calculated to keep the vehicle in the traveling lane and using a second turning angle corresponding to the steering amount of the steering wheel. The lane keeping assist device detects a vehicle speed of the vehicle. The lane keeping assist device calculates a first reaction force command value to the steering wheel corresponding to the first turning angle and a second reaction force command value to the steering wheel corresponding to the second turning angle. The lane keeping assist device controls a steering reaction force to be imparted to the steering wheel to correspond only to the second reaction force command value when the vehicle speed is higher than a predetermined threshold value.

Claims

1. A lane keeping assist device that assists a vehicle to travel within a traveling lane, in which a steering wheel in the vehicle and a turning wheel for turning the vehicle are mechanically detached, the lane keeping assist device comprising:

a turn control unit that controls a turning angle of the turning wheel using a first turning angle calculated to keep the vehicle in the traveling lane and using a second turning angle that corresponds to a steering amount of the steering wheel;

a vehicle speed detection unit that detects a vehicle speed of the vehicle;

a reaction force command value calculation unit that calculates a first reaction force command value to the steering wheel corresponding to the first turning angle, and that calculates a second reaction force command value to the steering wheel corresponding to the second turning angle; and

a steering reaction force control unit that controls a steering reaction force to be imparted to the steering wheel to correspond only to the second reaction force command value when the vehicle speed is higher than a predetermined threshold value, and that controls the steering reaction force to be imparted to the steering wheel to correspond to the first reaction force command value and the second reaction force command value when the vehicle speed is at the predetermined threshold value or less.

2. The lane keeping assist device according to claim 1, wherein

the steering reaction force control unit is configured to control the steering reaction force using a total of values obtained by multiplying a ratio corresponding to the vehicle speed by the first reaction force command value and the second reaction force command value, respectively.

3. The lane keeping assist device according to claim 1, wherein

the steering reaction force control unit is configured to control the steering reaction force using a larger of the first reaction force command value and the second reaction force command value, when the vehicle speed is equal to or less than the predetermined threshold value.

4. The lane keeping assist device according to claim 1, wherein

the steering reaction force control unit is configured to control the steering reaction force using a total value of the first reaction force command value and the second reaction force command value, when the vehicle speed is equal to or less than the predetermined threshold value.

5. The lane keeping assist device according to claim 1, wherein,

when the vehicle speed is equal to or less than the predetermined threshold value, the steering reaction force control unit is configured to control the steering reaction force using a larger of the first reaction force command value and the second reaction force command value upon determining a rotational direction of the steering wheel is in a direction to cause the vehicle to approach a center side of the lane, and is configured to control the steering reaction force using a total value of the first reaction force command value and the second reaction force command value, upon determining the rotational direction of the steering wheel is not in a direction to cause the vehicle to approach the center side of the lane.

6. The lane keeping assist device according to claim 1, wherein

the steering reaction force control unit is configured to control the steering reaction force using an average value of the first reaction force command value and the second reaction force command value, when the vehicle speed is equal to or less than the predetermined threshold value.

7. The lane keeping assist device according to claim 1, wherein

the steering reaction force control unit is configured to set the second reaction force command value to zero when the vehicle speed is higher than the predetermined threshold value.

8. A lane keeping assist device that assists a vehicle to travel within a traveling lane, in which a steering wheel in the vehicle and a turning wheel for turning the vehicle are mechanically detached, the lane keeping assist device comprising:

a turn control unit that controls a turning angle of the turning wheel using a first turning angle calculated to keep the vehicle in the traveling lane and using a second turning angle that corresponds to a steering amount of the steering wheel;

a vehicle speed detection unit that detects a vehicle speed of the vehicle;

a reaction force command value calculation unit that calculates a first reaction force command value to the steering wheel corresponding to the first turning angle, and that calculates a second reaction force command value to the steering wheel corresponding to the second turning angle; and

a steering reaction force control unit that controls the steering reaction force to be imparted to the steering wheel to correspond the first reaction force command value and the second reaction force command value;

the reaction force command value calculation unit calculating the first reaction force command value such that the first reaction force command value becomes larger when the vehicle speed is equal to or less than a predetermined threshold value as compared to when the vehicle speed is higher than the predetermined threshold value.

9. The lane keeping assist device according to claim 8, wherein

the steering reaction force control unit is configured to control the steering reaction force using a total of values obtained by multiplying a ratio corresponding to the vehicle speed by the first reaction force command value and the second reaction force command value, respectively.

10. The lane keeping assist device according to claim 8, wherein

the steering reaction force control unit is configured to control the steering reaction force using a larger of the first reaction force command value and the second reaction force command value, when the vehicle speed is equal to or less than the predetermined threshold value.

11. The lane keeping assist device according to claim 8, wherein

the steering reaction force control unit is configured to control the steering reaction force using a total value of the first reaction force command value and the second reaction force command value, when the vehicle speed is equal to or less than the predetermined threshold value.

12. The lane keeping assist device according to claim 8, wherein

when the vehicle speed is equal to or less than the predetermined threshold value, the steering reaction force control unit is configured to control the steering reaction force using a larger of the first reaction force command value and the second reaction force command value upon determining a rotational direction of the steering wheel is in a direction to cause the vehicle to approach a center side of the lane, and is configured to control the steering reaction force using a total value of the first reaction force command value and the second reaction force command value, upon determining the rotational direction of the steering wheel is not in a direction to cause the vehicle to approach the center side of the lane.

13. The lane keeping assist device according to claim 8, wherein

the steering reaction force control unit is configured to control the steering reaction force using an average value of the first reaction force command value and the second reaction force command value, when the vehicle speed is equal to or less than the predetermined threshold value.

14. The lane keeping assist device according to claim 8, wherein

the steering reaction force control unit is configured to set the second reaction force command value to zero when the vehicle speed is higher than the predetermined threshold value.