Time To Avoid Collision For Active Steering Safety Systems

• US 20150251656A1
• Filed: 11/04/2014
• Published: 09/10/2015
• Est. Priority Date: 03/05/2014
• Status: Active Grant

• Current Assignee: DENSO Corporation, Denso International America Incorporated (DENSO Corporation)
• Original Assignee: DENSO Corporation, Denso International America Incorporated (DENSO Corporation)
• Inventors: YESTER, John, RIPARIP, Hans, SUN, Bo, HATTORI, Hiroshi, AKAMATSU, Katsuhiko
• Granted Patent: US 9,555,801 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• 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 2552/40 Coefficient of friction
• CPC Class Codes: B60W 2554/801 Lateral distance
• CPC Class Codes: B60W 30/09 Taking automatic action to avoid collision, e.g. braking and steering
• CPC Class Codes: B60W 30/18163 Lane change; Overtaking manoeuvres
• CPC Class Codes: B62D 15/0265 Automatic obstacle avoidance by steering

Abstract

The present teachings provide for an active steering system for controlling a vehicle. The system can include at least one sensor and a control module. The at least one sensor can be configured to detect a leading obstacle. The control module can be configured to receive a signal from the at least one sensor, to determine a steering profile, and to execute a lane change maneuver based on the steering profile. The steering profile can include a plurality of steering angles and corresponding vehicle positions for maneuvering the vehicle from a current lane to an adjacent lane. The steering angles can be calculated to not increase the acceleration of the vehicle above an occupant comfort threshold value and to not cause the vehicle to cross an outer boundary of the adjacent lane.

Claims

1. An active steering system for controlling a vehicle, the system comprising:

at least one sensor configured to detect a leading obstacle; and

a control module configured to receive a signal from the at least one sensor, to determine a steering profile, and to execute a lane change maneuver based on the steering profile;

wherein the steering profile includes a plurality of steering angles and corresponding vehicle positions for maneuvering the vehicle from a current lane to an adjacent lane, the steering angles being calculated to not increase the acceleration of the vehicle above an occupant comfort threshold value and to not cause the vehicle to cross an outer boundary of the adjacent lane.

2. The system of claim 1, wherein the control module is configured to calculate the steering profile using a value representative of a coefficient of friction between a pair of wheels of the vehicle and the current lane.

3. The system of claim 2, wherein the control module is configured to calculate the steering profile using a value representative of a coefficient of friction between the pair of wheels and the adjacent lane.

4. The system of claim 1, wherein the control module is configured to control a brake system to selectively decelerate the vehicle.

5. The system of claim 1, wherein the at least one sensor is configured to detect a leading adjacent obstacle in the adjacent lane and ahead of the vehicle, and a trailing adjacent obstacle in the adjacent lane and behind the vehicle, wherein the control module is configured to calculate the steering profile based on a relative velocity of the vehicle and at least one of the leading adjacent obstacle and the trailing adjacent obstacle, and wherein the control module is configured to calculate the steering profile based on a distance between the vehicle and at least one of the leading adjacent obstacle and the trailing adjacent obstacle.

6. The system of claim 1, further comprising a database configured to provide pre-programmed data to the control module, wherein the control module is configured to calculate the steering profile based on the pre-programmed data from the database.

7. The system of claim 1, wherein the at least one sensor is configured to detect an object in an adjacent lane, and the control module is configured to only execute the lane change maneuver when the lane change maneuver can be completed without the object in the adjacent lane becoming closer than a safe distance to the vehicle.

8. An active steering system for controlling a vehicle, the system comprising:

at least one sensor configured to detect a leading obstacle and an adjacent obstacle; and

a control module configured to receive a signal from the at least one sensor, to calculate a steering profile, and to execute a lane change maneuver based on the steering profile;

wherein the steering profile includes a plurality of steering angles and corresponding vehicle positions for maneuvering the vehicle from a current lane to an adjacent lane, the steering angles being calculated by the control module to not increase the acceleration of the vehicle above an occupant comfort threshold value and to not cause the vehicle to cross an outer boundary of the adjacent lane; and

wherein the steering profile is calculated based on a relative distance and velocity of the vehicle and the leading obstacle, a relative distance and velocity of the vehicle and the adjacent obstacle.

9. The system of claim 8, wherein the control module is configured to control a brake system to selectively decelerate the vehicle.

10. The system of claim 8, wherein the control module is configured to calculate the steering profile using at least one value representative of a coefficient of friction between a pair of wheels of the vehicle and the current lane, the adjacent lane, or both the current lane and the adjacent lane.

11. The system of claim 8, further comprising a database configured to provide pre-programmed data to the control module, wherein the control module is configured to calculate the steering profile based on the pre-programmed data from the database.

12. A method for actively controlling a vehicle traveling in a current lane of a roadway, the method comprising:

providing a vehicle with a control module and a plurality of sensors;

the sensors sending at least one signal to the control module;

the control module determining if a lane change is required;

the control module determining if an adjacent lane is available;

the control module using occupant comfort and distance between the vehicle and an outer boundary of the adjacent lane to calculating a steering profile wherein the vehicle will not cross the outer boundary of the adjacent lane; and

the control module controlling a steering system of the vehicle to perform a lane change maneuver based on the steering profile.

13. The method of claim 12, further comprising:

the control module determining the vehicle'"'"'s position in the roadway during the lane change maneuver;

the control module comparing the vehicle'"'"'s position in the roadway with an expected position of the steering profile;

the control module creating a new steering profile; and

the control module controlling the steering system to perform the lane change maneuver based on the new steering profile.

14. The method of claim 13, wherein the step of the control module determining if a lane change is required includes:

the control module determining a position and a relative velocity of a leading obstacle, the position including the distance between the vehicle and the leading obstacle;

the control module calculating the rate of deceleration required to avoid a collision between the vehicle and the leading obstacle;

the control module calculating the deceleration rate available to the vehicle; and

the control module comparing the deceleration rate required to avoid collision between the vehicle and the leading obstacle to the deceleration rate available to the vehicle.

15. The method of claim 14, wherein the step of the control module determining if a lane change is required further includes:

the control module determining an adequate distance between the vehicle and the leading obstacle for avoiding the collision between the vehicle and the leading obstacle; and

comparing the distance between the vehicle and leading obstacle to the adequate distance.

16. The method of claim 15, wherein the step of the control module determining if a lane change is required further includes:

estimating the coefficient of friction between a set of wheels of the vehicle and the current lane; and

estimating the coefficient of friction between the set of wheels of the vehicle and the adjacent lane.

17. The method of claim 15, wherein the step of the control module determining an adequate distance between the vehicle and the leading obstacle for avoiding the collision between the vehicle and the leading obstacle includes:

the control module determining the width of the current lane and the lateral distance from the vehicle to the outer boundary of the adjacent lane;

the control module determining a maximum steering rate for the current and adjacent lanes;

the control module determining a lateral movement needed to avoid the leading obstacle; and

the control module calculating the adequate distance to change lanes without exceeding predetermined comfort values and without crossing the outer boundary of the adjacent lane.

18. The method of claim 12, wherein the step of the control module determining if an adjacent lane is available includes:

the control module determining if any adjacent obstacles are detected in the adjacent lane;

if a leading adjacent obstacle exists, the control module determining a safe lead distance between the vehicle and the leading adjacent obstacle and comparing the distance between the vehicle and the leading adjacent obstacle to the safe lead distance; and

if a trailing adjacent obstacle exists, the control module determining a safe trailing distance between the vehicle and the trailing adjacent obstacle and comparing the distance between the vehicle and the trailing adjacent obstacle to the safe trailing distance.

19. The method of claim 18, wherein the step of the control module determining if an adjacent lane is available further includes:

If the distance between the vehicle and the leading adjacent obstacle is not greater than the safe lead distance, then the control module sending a control signal to a braking system to reduce the speed of the vehicle.

20. The method of claim 19, wherein the step of the control module determining if an adjacent lane is available further includes:

the control module determining the relative velocities of the leading adjacent obstacle and the trailing adjacent obstacle;

the control module calculating the time the distance between the leading adjacent object and the vehicle will remain greater than the safe leading distance;

the control module calculating the time the distance between the trailing adjacent object and the vehicle will remain greater than the safe trailing distance;

the control module calculating the time required to complete a lane change;

the control module comparing the time required to complete a lane change to the time the distance between the leading adjacent object and the vehicle will remain greater than the safe leading distance; and

the control module comparing the time required to complete a lane change to the time the distance between the trailing adjacent object and the vehicle will remain greater than the safe trailing distance.