Automotive lane deviation prevention apparatus

• US 20050125153A1
• Filed: 12/02/2004
• Published: 06/09/2005
• Est. Priority Date: 12/03/2003
• Status: Active Grant

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Matsumoto, Shinji, Tange, Satoshi, Yoshizawa, Hiroyuki, Shimakage, Masayasu
• Granted Patent: US 7,698,032 B2
• Time in Patent Office: Days
• US Class Current: 701/300
• CPC Class Codes: B60T 2201/08 Lane monitoring; Lane Keeping Systems
• CPC Class Codes: B60T 2201/081 using distance control
• CPC Class Codes: B60T 2201/083 using active brake actuation
• CPC Class Codes: B60T 2201/087 using active steering actuation
• CPC Class Codes: B60T 2210/14 Rough roads, bad roads, gravel roads
• CPC Class Codes: B60T 8/17557 specially adapted for lane departure prevention road vehicle drive control systems for lane keeping otherwise than by controlling a particular sub-unit B60W30/12
• CPC Class Codes: B60W 10/18 including control of braking systems
• CPC Class Codes: B60W 10/20 including control of steering systems
• CPC Class Codes: B60W 30/12 Lane keeping
• 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

An automotive lane deviation prevention (LDP) apparatus includes a control unit detecting whether a host vehicle is in a specific state where the host vehicle is traveling on road-surface irregularities formed on or close to a lane marking line. The control unit actively decelerates the host vehicle when the host vehicle is in the specific state where the host vehicle is traveling on the road-surface irregularities.

Claims

1. An automotive lane deviation prevention (LDP) apparatus comprising:

a processor programmed to perform the following,

(a) detecting whether a host vehicle is in a state where the host vehicle is traveling on road-surface irregularities formed on or close to a lane marking line; and

(b) actively decelerating the host vehicle when the host vehicle is in the state where the host vehicle is traveling on the road-surface irregularities.

2. An automotive lane deviation prevention (LDP) apparatus comprising:

a road-surface irregularities detector that detects whether a host vehicle is in a state where the host vehicle is traveling on road-surface irregularities formed on or close to a lane marking line;

an actuator capable of decelerating the host vehicle; and

a control unit configured to be electronically connected to the road-surface irregularities detector and the actuator for LDP control purposes;

the control unit comprising;

a vehicle deceleration control section that executes vehicle deceleration control to actively decelerate the host vehicle when the host vehicle is in the state where the host vehicle is traveling on the road-surface irregularities.

3. The LDP apparatus as claimed in claim 2, wherein:

the road-surface irregularities detector comprises wheel speed sensors that detect respective wheel speeds of road wheels of the host vehicle; and

the road-surface irregularities detector determines, based on the wheel speeds, whether the host vehicle is in the state where the host vehicle is traveling on the road-surface irregularities.

4. The LDP apparatus as claimed in claim 3, wherein:

the road-surface irregularities detector determines that the host vehicle is in the state where the host vehicle is traveling on the road-surface irregularities, when either one of the left and right wheel speeds is fluctuating.

5. The LDP apparatus as claimed in claim 3, wherein:

the road-surface irregularities detector determines that the host vehicle is in the state where the host vehicle is traveling on the road-surface irregularities, when the wheel speed is fluctuating at a substantially constant time period determined based on a host vehicle speed.

6. The LDP apparatus as claimed in claim 3, further comprising:

a host vehicle'"'"'s position information detector that detects position information regarding a position of the host vehicle on a map,

wherein the road-surface irregularities detector determines, based on the host vehicle'"'"'s position information and the wheel speeds, that the host vehicle is in the state where the host vehicle is traveling on the road-surface irregularities, when the wheel speed of the host vehicle, traveling on a driving lane, is fluctuating.

7. The LDP apparatus as claimed in claim 2, further comprising:

a vehicle-suspension up-and-down motion sensor that detects an up-and-down motion of a suspension of the host vehicle,

wherein the road-surface irregularities detector determines, based on the suspension'"'"'s up-and-down motion detected, whether the host vehicle is in the state where the host vehicle is traveling on the road-surface irregularities.

8. The LDP apparatus as claimed in claim 2, further comprising:

a picture image pick-up device that picks up a picture image in front of the host vehicle; and

a lane marker detector that detects a lane marking line on a driving lane of the host vehicle, based on the picture image picked up by the picture image pick-up device,

wherein the control unit further comprises;

a lane-deviation tendency detection section that determines, based on a host vehicle'"'"'s lateral deviation estimated based the lane marking line, whether the host vehicle is in a state where there is an increased tendency for the host vehicle to deviate from the driving lane or in a state where there is a less tendency for the host vehicle to deviate from the driving lane; and

an LDP control section that executes yaw moment control by which the host vehicle'"'"'s lane deviation tendency is avoided, when the host vehicle is in the state where there is an increased tendency for the host vehicle to deviate from the driving lane.

9. The LDP apparatus as claimed in claim 8, wherein:

the vehicle deceleration control section determines a vehicle-deceleration-control controlled variable based on the host vehicle'"'"'s lateral deviation.

10. The LDP apparatus as claimed in claim 8, further comprising:

a vehicle'"'"'s driving state and traveling-path condition detector that detects at least a driving state of the host vehicle,

wherein the control unit comprises a control allotted rate decision section that determines, based on the driving state, a control allotted rate of vehicle deceleration control to yaw moment control, and the vehicle deceleration control and the yaw moment control are executed based on the control allotted rate.

11. The LDP apparatus as claimed in claim 10, wherein:

the vehicle'"'"'s driving state and traveling-path condition detector that detects at least one of a host vehicle speed, a yaw rate resulting from a yaw moment acting on the host vehicle, a lateral acceleration exerted on the host vehicle, a yaw angle with respect to a sense of a driving lane of the host vehicle, and a curvature of the host vehicle'"'"'s driving lane.

12. The LDP apparatus as claimed in claim 8, wherein:

the control unit further comprises;

a lane-marker unrecognizable state detection section that determines whether the host vehicle is in a lane-marker unrecognizable state where the lane marking line cannot be detected by the picture image pick-up device or in a lane-marker recognizable state where the lane marking line can be detected by the picture image pick-up device,

wherein the vehicle deceleration control section fixes a vehicle-deceleration-control controlled variable to a preset constant value, when the lane-marker unrecognizable state detection section determines that the host vehicle is in the lane-marker unrecognizable state and additionally the road-surface irregularities detector determines that the host vehicle is in the state where the host vehicle is traveling on the road-surface irregularities.

13. The LDP apparatus as claimed in claim 8, wherein:

the control unit further comprises;

a lane-marker unrecognizable state detection section that determines whether the host vehicle is in a lane-marker unrecognizable state where the lane marking line cannot be detected by the picture image pick-up device or in a lane-marker recognizable state where the lane marking line can be detected by the picture image pick-up device; and

a virtual-deviation-estimate based lane-deviation possibility estimation section that estimates, based on a virtual deviation estimate estimated based on historical data concerning a vehicle'"'"'s driving state and a traveling-path condition of the host vehicle, all obtained just before a transition from the lane-marker recognizable state to the lane-marker unrecognizable state, whether the host vehicle is in a state where there is a high possibility for the host vehicle to deviate from the driving lane or in a state where there is a low possibility for the host vehicle to deviate from the driving lane,

wherein the vehicle deceleration control section fixes a vehicle-deceleration-control controlled variable to a preset constant value, when the virtual-deviation-estimate based lane-deviation possibility estimation section determines that the host vehicle is in the state where there is a high possibility for the host vehicle to deviate from the driving lane in the lane-marker unrecognizable state and additionally the road-surface irregularities detector determines that the host vehicle is in the state where the host vehicle is traveling on the road-surface irregularities.

14. The LDP apparatus as claimed in claim 10, wherein:

the vehicle'"'"'s driving state and traveling-path condition detector that detects a host vehicle speed, a yaw angle with respect to a sense of a driving lane of the host vehicle, a lateral displacement of the host vehicle from a central axis of the driving lane, and a curvature of the host vehicle'"'"'s driving lane;

the lane-deviation tendency detection section estimates a future lateral-displacement estimate based on the host vehicle speed, the yaw angle, the lateral displacement, and the curvature; and

the lane-deviation tendency detection section determines that the host vehicle is in the state where there is an increased tendency for the host vehicle to deviate from the driving lane, when an absolute value of the future lateral-displacement estimate is greater than or equal to a predetermined lateral-displacement criterion.

15. The LDP apparatus as claimed in claim 8, further comprising:

a braking/driving force control device that controls braking/driving forces of the road wheels,

wherein the LDP control section comprises a braking/driving force controlled variable calculation section that calculates a braking/driving force controlled variable of each of the road wheels so that a yaw moment is produced in a direction in which the host vehicle'"'"'s lane-deviation tendency is avoided, when the lane-deviation tendency detection section determines that the host vehicle is in the state where there is an increased tendency for the host vehicle to deviate from the driving lane; and

the braking/driving force control device controls the braking/driving forces of the road wheels, responsively to the braking/driving force controlled variables calculated.

16. The LDP apparatus as claimed in claim 15, wherein:

the braking/driving force control device comprises a hydraulic modulator capable of controlling the braking forces of the road wheels, independently of a driver'"'"'s brake-pedal depression.

17. The LDP apparatus as claimed in claim 15, wherein:

the braking/driving force controlled variable calculation section calculates the braking/driving force controlled variables of the respective road wheels, based on a desired yaw moment calculated based on a difference between the future lateral-displacement estimate and the predetermined lateral-displacement criterion.

18. The LDP apparatus as claimed in claim 8, further comprising:

a steering control device that controls a steering torque applied to a steering system of the host vehicle independently of a driver'"'"'s steering action,

wherein the LDP control section comprises a steering torque controlled variable calculation section that calculates a steering torque controlled variable of the steering system so that a yaw moment is produced in a direction in which the host vehicle'"'"'s lane-deviation tendency is avoided, when the lane-deviation tendency detection section determines that the host vehicle is in the state where there is an increased tendency for the host vehicle to deviate from the driving lane; and

the steering control device controls the steering torque applied to the steering system, responsively to the steering torque controlled variable calculated.

19. An automotive lane deviation prevention (LDP) apparatus comprising:

road-surface irregularities detection means for detecting whether a host vehicle is in a state where the host vehicle is traveling on road-surface irregularities formed on or close to a lane marking line;

an actuator capable of decelerating the host vehicle; and

a control unit configured to be electronically connected to the road-surface irregularities detection means and the actuator for LDP control purposes;

the control unit comprising;

vehicle deceleration control means for executing vehicle deceleration control to actively decelerate the host vehicle when the host vehicle is in the state where the host vehicle is traveling on the road-surface irregularities.

20. A method of preventing lane deviation of a host vehicle employing braking force actuators that adjust braking forces applied to respective road wheels, the method comprising:

(a) detecting whether a host vehicle is in a state where the host vehicle is traveling on road-surface irregularities formed on or close to a lane marking line; and

(b) executing vehicle deceleration control actively decelerating the host vehicle when the host vehicle is in the state where the host vehicle is traveling on the road-surface irregularities.

21. The method as claimed in claim 20, further comprising:

(c) executing yaw moment control actively exerting a yaw moment on the host vehicle simultaneously with the active vehicle deceleration control when the host vehicle is in the state where the host vehicle is traveling on the road-surface irregularities.

22. The method as claimed in claim 20, further comprising:

(d) determining whether the host vehicle is in a lane-marker unrecognizable state where the lane marking line cannot be detected by a picture image pick-up device or in a lane-marker recognizable state where the lane marking line can be detected by the picture image pick-up device;

(e) fixing a desired deceleration rate for the active vehicle deceleration control to a preset constant value when the host vehicle is in the state where the host vehicle is traveling on the road-surface irregularities in the lane-marker unrecognizable state.