Intersection collision avoidance with adaptable vehicle dimensions

• US 8,706,393 B2
• Filed: 01/10/2012
• Issued: 04/22/2014
• Est. Priority Date: 01/10/2012
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Miller, Alex Maurice, Trombley, Roger Arnold
• Primary Examiner(s): Nguyen, Kim T
• Application Number:
  US13/346,743
• Publication Number:
  US 20130179047A1
• Time in Patent Office: 833 Days
• Field of Search: 701/70, 701/400, 701/412, 701/527, 701/300, 701/301, 701/302
• US Class Current: 701/301
• CPC Class Codes: B60W 10/184 with wheel brakes
• CPC Class Codes: B60W 2510/182 Brake pressure, e.g. of fluid or between pad and disc
• CPC Class Codes: B60W 2720/10 Longitudinal speed
• CPC Class Codes: B60W 2720/106 Longitudinal acceleration
• 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: B60W 30/143 Speed control B60W30/16 takes precedence
• CPC Class Codes: B60W 30/18154 Approaching an intersection
• CPC Class Codes: G08G 1/166 for active traffic, e.g. moving vehicles, pedestrians, bikes

Abstract

A method for avoiding a collision between a host vehicle and a target vehicle defines the intersection of their trajectories as the potential collision zone. The method calculates the distance to be traversed and the time required for the target vehicle to reach the collision zone and to clear it. The method then incorporates the possible cases when the target vehicle may be towing a trailer, and uses an adjusted value for the length of the target vehicle for further calculations in such cases. Further, the deceleration required by the host vehicle to allow the target vehicle to pass safely under a ‘brake to pass’ condition is calculated. The method then evaluates a break threat number based on this deceleration value and provides warning signals to the occupant of the host vehicle, to apply the brakes immediately or after a certain time, based on the break threat number value.

Claims

1. A method for avoiding collision between a host vehicle and a target vehicle, wherein the host vehicle is equipped with a collision avoidance system, including one or more sensors for detecting the presence of nearby vehicles and calculating means for processing signals from the sensors, the method comprising:

locating current positions of the host vehicle and the target vehicle, employing the one or more sensors;

defining a potential collision zone, employing the calculating means, including assuming target and host vehicle lengths,

determining whether the assumed vehicle lengths are incorrect, and if incorrect, adjusting the assumed lengths;

checking whether the target vehicle currently intercepts a host vehicle'"'"'s path, taking into consideration the adjusted assumed lengths of the vehicles;

predicting host vehicle'"'"'s position at an instant when the target vehicle is expected to reach the potential collision zone;

calculating a host vehicle speed change value required by the host vehicle to avoid a collision with the target vehicle, based on the adjusted assumed lengths; and

providing signals from the collision avoidance system to a controller on the host vehicle to effect the host vehicle speed change.

2. The method of claim 1, wherein defining the potential collision zone includes projecting current trajectories of the host vehicle and the target vehicle forward along their respective directions of motion, and determining a intersection of the projected trajectories.

3. The method of claim 1, further comprising calculating, for the target vehicle, from its current position, a distance to be traversed and a time required to reach the potential collision zone.

4. The method of claim 3, further comprising, calculating, for the target vehicle, from its current position, the distance to be traversed and the time required to clear the potential collision zone.

5. The method of claim 1, further comprising calculating a distance to be traversed by the host vehicle from its current position, to reach the potential collision zone.

6. The method of claim 1, further comprising, adjusting the assumed lengths by adding the actual length of the host vehicle or the target vehicle, to the length of a towed object, if either the host vehicle or the target vehicle, respectively, tows the object.

7. The method of claim 1, wherein checking whether the target vehicle currently intercepts a host vehicle further comprises, comparing, for the target vehicle, a value corresponding to a distance to be traversed from its current position, to reach the potential collision zone, with a value corresponding to a distance to be traversed from its current position to clear the potential collision zone, and declaring the interception if the two values are of opposite signs.

8. The method of claim 1, further comprising determining host vehicle'"'"'s position when the target vehicle is expected to enter the potential collision zone.

9. The method of claim 8, further comprising determining a current position of the host vehicle'"'"'s front portion with respect to a proximal side of the target vehicle, the current position being determined along a longitudinal direction substantially parallel to the direction of motion of the host vehicle.

10. The method of claim 9, further comprising determining a current position of the host vehicle'"'"'s rear portion with respect to a distal side of the target vehicle, the position being determined along the longitudinal direction.

11. The method of claim 8, further comprising calculating the distance between the rear portion of the host vehicle and a distal side of the target vehicle, at the time when the target vehicle is expected to reach the potential collision zone.

12. The method of claim 1, wherein calculating the host vehicle speed change value further comprises calculating the distance between a front portion of the host vehicle and a proximal side of the target vehicle, at a time when the target vehicle is expected to clear the potential collision zone.

13. The method of claim 1, further comprising calculating a break threat number value by dividing the host vehicle speed change value with a maximum deceleration value that the host vehicle can achieve.

14. The method of claim 13, wherein if the break threat number'"'"'s value is 1, then warming the host vehicle'"'"'s occupant to apply brakes instantaneously to achieve a maximum deceleration.

15. The method of claim 13, further comprising, establishing a threshold value corresponding to the break threat number value, and providing warning signals to the host vehicle'"'"'s occupant if the calculated break threat number value exceeds the threshold value.

16. The method of claim 1, further comprising, calculating a brake threat number value using the required host vehicle speed change value;

and providing signals to the host vehicle based on the break threat number value.