Method of Controlling a Collision Warning System Using Line of Sight

• US 20120068859A1
• Filed: 09/20/2010
• Published: 03/22/2012
• Est. Priority Date: 09/20/2010
• Status: Active Grant

• Current Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Original Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Inventors: Mochizuki, Yutaka
• Granted Patent: US 8,558,718 B2
• Time in Patent Office: Days
• US Class Current: 340/903
• CPC Class Codes: B60R 21/0134 responsive to imminent contact with an obstacle , e.g. using radar systems
• CPC Class Codes: G08G 1/161 Decentralised systems, e.g. inter-vehicle communication
• CPC Class Codes: G08G 1/163 involving continuous checking
• CPC Class Codes: G08G 1/166 for active traffic, e.g. moving vehicles, pedestrians, bikes

Abstract

A collision warning system for a motor vehicle is disclosed. The collision warning system includes a first mode and a second mode. The system operates in the first mode when there is line of sight with a target vehicle. The system operates in the second mode where there is no line of sight with the target vehicle.

Claims

1. A method of operating a collision warning system in a motor vehicle, comprising the steps of:

receiving information related to a target vehicle;

determining if the target vehicle is in a line of sight of the motor vehicle;

the collision warning system including multiple alert modes;

operating the collision warning system in a normal alert mode when the target vehicle is in the line of sight of the motor vehicle;

operating the collision warning system in an enhanced alert mode when the target vehicle is not in the line of sight of the motor vehicle; and

wherein the normal alert mode is different than the enhanced alert mode.

2. The method according to claim 1, wherein the step of determining if the target vehicle is in the line of sight of the motor vehicle further includes the steps of:

receiving a measured signal characteristic from a signal transmitted by the target vehicle;

retrieving a reference signal characteristic; and

determining a line of sight condition for the motor vehicle with respect to the target vehicle using the measured signal characteristic and the reference signal characteristic.

3. The method according to claim 1, wherein the step of determining if the target vehicle is in the line of sight of the motor vehicle further includes the steps of:

receiving information related to the target vehicle;

receiving information related to an intermediate vehicle; and

determining if the intermediate vehicle obstructs the line of sight between the motor vehicle and the target vehicle.

4. The method according to claim 1, wherein the step of operating the collision warning system further includes the steps of:

determining that the collision warning system is operating in the normal alert mode;

calculating a threat level, the threat level being associated with a threat of collision between the motor vehicle and the target vehicle and wherein the threat level is associated with a first threat level and a second threat level that is higher than the first threat level;

issuing a warning alert when the threat level is the second threat level; and

issuing no alert when the threat level is the first threat level.

5. The method according to claim 1, wherein the step of operating the collision warning system further includes the steps of:

determining that the collision warning system is operating in the enhanced alert mode;

calculating a threat level, the threat level being associated with a threat of collision between the motor vehicle and the target vehicle and wherein the threat level is associated with a first threat level and a second threat level that is higher than the first threat level;

issuing a warning alert when the threat level is the second threat level; and

issuing an informing alert when the threat level is the first threat level.

6. The method according to claim 1, wherein the normal alert mode is associated with a warning alert only and wherein the enhanced alert mode is associated with an informing alert and a warning alert.

7. A method of operating a collision warning system in a motor vehicle, comprising the steps of:

receiving a signal transmitted by a target vehicle;

determining a measured signal characteristic from the signal transmitted by the target vehicle;

retrieving a reference signal characteristic corresponding to the measured signal characteristic;

determining a line of sight condition for the motor vehicle with respect to the target vehicle using the measured signal characteristic and the reference signal characteristic;

operating the collision warning system in a normal alert mode when the target vehicle is in the line of sight of the motor vehicle;

operating the collision warning system in an enhanced alert mode when the target vehicle is not in the line of sight of the motor vehicle; and

wherein the normal alert mode is different than the enhanced alert mode.

8. The method according to claim 7, wherein the measured signal characteristic is a received signal strength index of the signal.

9. The method according to claim 7, wherein the measured signal characteristic is a packet success ratio of the signal.

10. The method according to claim 7, wherein the measured signal characteristic is a first power component of the signal.

11. The method according to claim 7, wherein the measured signal characteristic is associated with a correlation between two or more receiving antennas.

12. The method according to claim 7, wherein the measured signal characteristic is associated with a plurality of measured signal characteristics.

13. The method according to claim 7, wherein the number of alerts issued in the enhanced alert mode is greater than the number of alerts issued in the normal alert mode.

14. The method according to claim 7, wherein the measured signal characteristic, the reference signal characteristic and a distance to the target vehicle are used to determine the line of sight condition for the motor vehicle with respect to the target vehicle.

15. A method of operating a collision warning system in a motor vehicle, comprising the steps of:

receiving information related to a target vehicle;

receiving information related to an intermediate vehicle;

determining if the intermediate vehicle obstructs the line of sight between the motor vehicle and the target vehicle;

operating the collision warning system in a normal alert mode when the target vehicle is in the line of sight of the motor vehicle; and

operating the collision warning system in an enhanced alert mode when the target vehicle is not in the line of sight of the motor vehicle.

16. The method according to claim 15, wherein the step of determining if the intermediate vehicle obstructs the line of sight further includes the steps of:

receiving information related to a location of the intermediate vehicle;

calculating a headway distance between the motor vehicle and the intermediate vehicle;

retrieving a predetermined headway distance;

determining that the intermediate vehicle does not obstruct the line of sight between the motor vehicle and the target vehicle when the headway distance is greater than the predetermined headway distance; and

determining that the intermediate vehicle does obstruct the line of sight between the motor vehicle and the target vehicle when the headway distance is less than the predetermined headway distance.

17. The method according to claim 15, wherein the step of determining if the intermediate vehicle obstructs the line of sight further includes the steps of:

receiving information related to a vehicle size of the intermediate vehicle;

retrieving a predetermined vehicle size;

determining that the intermediate vehicle does not obstruct the line of sight between the motor vehicle and the target vehicle when the vehicle size is less than the predetermined vehicle size; and

determining that the intermediate vehicle does obstruct the line of sight between the motor vehicle and the target vehicle when the vehicle size is greater than the predetermined vehicle size.

18. The method according to claim 17, wherein the step of receiving information related to the vehicle size includes a step of receiving a vehicle type of the intermediate vehicle and estimating the vehicle size according to the vehicle type.

19. The method according to claim 17, wherein the vehicle size is associated with a vehicle width.

20. The method according to claim 15, wherein the line of sight of the motor vehicle with respect to the target vehicle is determined using a headway distance from the motor vehicle to the intermediate vehicle and an estimated width of the intermediate vehicle.