Method of Controlling A Collision Warning System Using Line Of Sight

• US 20110260846A1
• Filed: 04/26/2010
• Published: 10/27/2011
• Est. Priority Date: 04/26/2010
• Status: Active Grant

• Current Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Original Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Inventors: Mochizuki, Yutaka, Miucic, Radovan
• Granted Patent: US 8,749,365 B2
• Time in Patent Office: Days
• US Class Current: 340/435
• CPC Class Codes: B60Q 9/008 for anti-collision purposes

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. The line of sight conditions are determined according to power delay spread characteristics or frequency response characteristics of signals from a vehicle communications network.

Claims

1. 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 power delay spread characteristic from the signal transmitted by the target vehicle;

retrieving a reference power delay spread characteristic;

determining a line of sight condition for the motor vehicle with respect to the target vehicle using the power delay spread characteristic and the reference power delay spread characteristic; and

operating the collision warning system according to the line of sight condition.

2. The method according to claim 1, wherein the collision warning system is operated in an enhanced alert mode when the target vehicle is not in the line of sight of the motor vehicle.

3. The method according to claim 2, wherein the collision warning system is operated in a normal alert mode when the target vehicle is in the line of sight of the motor vehicle.

5. The method according to claim 1, wherein the collision warning system determines that there is line of sight when the power delay spread characteristic is less than the reference power delay spread characteristic.

6. The method according to claim 1, wherein the collision warning system determines that there is no line of sight when the power delay spread characteristic is greater than the reference power delay spread characteristic.

7. The method according to claim 1, wherein the power delay spread characteristic is a root mean square power delay spread.

4. The method according to claim 4, wherein the normal alert mode is different than the enhanced alert mode.

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

receiving a signal at a first antenna and a second antenna;

determining a first frequency response for the signal associated with the first antenna and a second frequency response for the signal associated with the second antenna;

calculating a measured antenna correlation using the first frequency response and the second frequency response;

determining a line of sight condition for the motor vehicle with respect to the target vehicle using the measured antenna correlation; and

operating the collision warning system according to the line of sight condition.

9. The method according to claim 8, wherein the collision warning system is operated in an enhanced alert mode when the target vehicle is not in the line of sight of the motor vehicle.

10. The method according to claim 9, wherein the collision warning system is operated in a normal alert mode when the target vehicle is in the line of sight of the motor vehicle.

11. The method according to claim 10, wherein the normal alert mode is different than the enhanced alert mode.

12. The method according to claim 8, wherein the method includes a step of retrieving a reference antenna correlation.

13. The method according to claim 12, wherein the step of determining a line of sight condition includes a step of comparing the measured antenna correlation with the reference antenna correlation.

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

receiving a signal;

determining a measured power variance associated with the signal, the measured power variance being the variance of the power as a function of frequency;

determining a line of sight condition for the motor vehicle with respect to the target vehicle using the measured power variance; and

operating the collision warning system according to the line of sight condition.

15. The method according to claim 14, wherein the step of determining the measured power variance includes a step of calculating a Fourier Transform for the signal.

16. The method according to claim 14, wherein the method includes a step of retrieving a reference power variance.

17. The method according to claim 16, wherein the step of determining a line of sight condition for the motor vehicle includes a step of comparing the measured power variance with the reference power variance.

18. The method according to claim 17, wherein the motor vehicle is determined to have line of sight when the measured power variance is less than the reference power variance.

19. The method according to claim 17, wherein the motor vehicle is determined to have no line of sight when the measured power variance is greater than the reference power variance.

20. The method according to claim 14, wherein the collision warning system is operated in an enhanced alert mode when the target vehicle is not in the line of sight of the motor vehicle.