FORWARD COLLISION RISK REDUCTION

• US 20110288774A1
• Filed: 05/17/2011
• Published: 11/24/2011
• Est. Priority Date: 05/17/2010
• Status: Active Grant

• Current Assignee: Polestar Performance AB (Polestar Automotive Holding UK Plc)
• Original Assignee: Volvo Car Corporation (AB Volvo)
• Inventors: Bengtsson, Mattias, Agnvall, Anders, Eidehall, Andreas
• Granted Patent: US 8,589,061 B2
• Time in Patent Office: Days
• US Class Current: 701/301
• CPC Class Codes: B60Q 1/00 Arrangement of optical signalling or lighting devices, the mounting or supporting thereof or circuits therefor for lighting vehicle interior B60Q3/00
• CPC Class Codes: B60W 30/09 Taking automatic action to avoid collision, e.g. braking and steering
• CPC Class Codes: B60W 30/095 Predicting travel path or likelihood of collision
• CPC Class Codes: G08G 1/16 Anti-collision systems road vehicle drive control systems for predicting or avoiding probable or impending collision otherwise than by control of a particular sub-unit B60W30/08
• CPC Class Codes: G08G 1/165 for passive traffic, e.g. including static obstacles, trees
• CPC Class Codes: G08G 1/166 for active traffic, e.g. moving vehicles, pedestrians, bikes

Abstract

A method for determining a safety zone of a foreign object for a forward collision risk reduction system. The method may include determining the type of the foreign object; setting the safety zone to a predetermined value corresponding to the type of the foreign object; determining the traffic behavior of the foreign object; determining if the traffic behavior corresponds to a species of a predetermined group of traffic behaviors; and if the traffic behavior corresponds to a species of a predetermined group of traffic behaviors, modifying the safety zone in accordance with a predetermined species function corresponding to the species.

Claims

1. A method for determining a safety zone of a foreign object for a forward collision risk reduction system, the foreign object being located in front of a vehicle hosting the system, the method comprising:

determining a type of the foreign object;

setting the safety zone based on the type of the foreign object;

determining at least one of a velocity and an acceleration of the foreign object;

determining the traffic behavior of the foreign object based on the at least one of the velocity and the acceleration;

determining if a traffic behavior corresponds to a species of a predetermined group of traffic behaviors; and

if the traffic behavior corresponds to a species of a predetermined group of traffic behaviors, modifying the safety zone in accordance with a predetermined species function corresponding to the species.

2. The method according to claim 1 wherein the method further comprises:

determining that the foreign object is a pedestrian, and

setting the safety zone to a predetermined pedestrian safety zone.

3. The method according to claim 1 wherein the predetermined group comprises a species that the foreign object is travelling towards a vehicle path of the vehicle but is expected to diverge from the vehicle path before colliding with the vehicle.

4. The method according to claim 1 wherein the predetermined group comprises a species that the foreign object is passing in front of the vehicle and it is estimated to avoid collision with a predetermined risk reduction margin.

5. The method according to claim 1 wherein the predetermined group comprises a species that the foreign object is stationary besides the vehicle path.

6. The method according to claim 1 wherein modifying the safety zone includes modifying an area of the safety zone from a first amount to a second amount.

7. The method according to claim 6 wherein the second amount is modified to be less than the first amount in the event an acceleration of the foreign object indicates the foreign object to be decelerating at a rate less than a deceleration threshold.

8. The method of claim 6 wherein the second amount is modified to be greater than the first amount in the event an acceleration of the foreign object indicates the foreign object to be decelerating at a rate greater than a deceleration threshold.

9. The method according to claim 8 wherein the deceleration threshold is in the range of 3-4 m/s².

10. The method according to claim 1 further comprising determining if the vehicle can avoid entering the safety zone by determining a braking threat number (BTN), the braking threat number (BTN) being the deceleration (decreq) required to avoid entering the safety zone divided by the maximum available deceleration (decavail) for the vehicle.

11. The method according to claim 1 further comprising determining if the vehicle can avoid entering the safety zone by determining a steering threat number (STN), the steering threat number (STN) being the lateral acceleration (alat,req) required to avoid entering the safety zone divided by the maximum available lateral acceleration (alat,avail) for the vehicle.

12. The method according to claim 1 further comprising determining if the vehicle can avoid entering the safety zone by determining that the vehicle cannot avoid entering the safety zone when each one of the braking threat number (BTN) and the steering threat number (STN) exceeds a predetermined threat number threshold value (BTNmax, STNmax).

13. The method according to claim 1 further comprising determining if the vehicle can avoid entering the safety zone in a controlled manner, and if not, issuing a warning.

14. The method according to claim 13 further comprising determining if the vehicle can avoid entering the safety zone in a controlled manner by determining a warning braking threat number (WBTN), the warning braking threat number (WBTN) being the required deceleration (decreq) required to avoid entering the safety zone (30) divided by the maximum deceleration (decavail,driver) that a driver normally uses when braking hard.

15. The method according to claim 13 further comprising determining if the vehicle can avoid entering the safety zone in a controlled manner by determining a warning steering threat number (WSTN), the warning steering threat number (WSTN) being the lateral acceleration (alat req) required to avoid entering the safety zone (30) divided by the maximum lateral acceleration (alat,driver) that a driver normally imparts the vehicle.

16. The method according to claim 13 further comprising determining if the vehicle can avoid entering the safety zone in a controlled manner by determining that the vehicle (10) cannot avoid entering the safety zone when each one of the warning braking threat number (WBTN) and the warning steering threat number (WSTN) exceeds a predetermined warning threat number threshold value (WBTNmax, WSTNmax).

17. The method according to claim 13 further comprising determining if the vehicle can avoid entering the safety zone in a controlled manner by determining the reaction time (TR) of the driver, and using the reaction time when determining the warning braking threat number (WBTN) and/or the warning steering threat number (WSTN).

18. For use with a forward collision risk reduction system of a vehicle traveling a roadway, a method for determining a safety zone of a foreign object approaching the roadway, the method comprising the steps of:

determining a type of the foreign object;

setting the safety zone to be a first amount based on the type of the foreign object;

determining a deceleration of the foreign object while approaching the roadway;

modifying the safety zone from the first amount to a second amount based on the deceleration.

19. The method of claim 18 wherein the second amount is less than the first amount and determined in the event the deceleration is greater than a deceleration threshold.

20. For use with a forward collision risk reduction system of a vehicle, a method for determining a safety zone of a foreign object, the method comprising the steps of:

determining a type of the foreign object;

setting the safety zone to be a first amount based on the type of the foreign object;

determining at least one of a velocity and a deceleration of the foreign object;

determining a behavior of the foreign object based on the at least one of the velocity and the acceleration;

determining if the traffic behavior corresponds to a plurality of a predetermined group of traffic behaviors;

if the traffic behavior corresponds to one of a plurality of a predetermined group of traffic behaviors, modifying the safety zone from the first amount to a second amount in accordance with the corresponding one of the plurality of predetermined group of traffic behaviors; and

determining at least one of;

i. if the vehicle can avoid entering the safety zone by determining a braking threat number (BTN), the braking threat number (BTN) being the deceleration (decreq) required to avoid entering the safety zone divided by the maximum available deceleration (decavail) for the vehicle.

ii. if the vehicle can avoid entering the safety zone by determining a steering threat number (STN), the steering threat number (STN) being the lateral acceleration (alat,req) required to avoid entering the safety zone divided by the maximum available lateral acceleration (alat,avail) for the vehicle.

iii. if the vehicle can avoid entering the safety zone by determining that the vehicle cannot avoid entering the safety zone when each one of the braking threat number (BTN) and the steering threat number (STN) exceeds a predetermined threat number threshold value (BTNmax, STNmax).