Pedestrian Alert System And Method

• US 20110199199A1
• Filed: 02/15/2010
• Published: 08/18/2011
• Est. Priority Date: 02/15/2010
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Perkins, William Paul
• Granted Patent: US 8,537,030 B2
• Time in Patent Office: Days
• US Class Current: 340/435
• CPC Class Codes: B60Q 1/506 specific to silent vehicles, e.g. for warning that a hybrid or electric vehicle is approaching
• CPC Class Codes: B60Q 1/525 automatically indicating risk of collision between vehicles in traffic or with pedestrians, e.g. after risk assessment using the vehicle sensor data
• CPC Class Codes: B60Q 5/008 for signaling silent vehicles, e.g. for warning that a hybrid or electric vehicle is approaching
• CPC Class Codes: B60Q 9/008 for anti-collision purposes
• CPC Class Codes: G08G 1/166 for active traffic, e.g. moving vehicles, pedestrians, bikes

Abstract

A pedestrian warning or alert system and method are disclosed. The warning system is mounted on an electric vehicle. The warning system includes a front speaker system, a rear speaker system, a front pedestrian detector, a rear pedestrian detector, and an electronic control unit (ECU) electronically coupled to the front speaker system, the rear speaker system, the front pedestrian detector, and the rear pedestrian detector. The ECU commands the front speaker system to emit a warning sound based on the front pedestrian detector detecting a pedestrian-shaped object and commands the rear speaker system to emit a warning sound based on the rear pedestrian detector detecting a pedestrian-shaped object. The ECU is coupled to a microphone, the signal of which is used to estimate an ambient noise level. The intensity and frequency of the warning sound commanded from the front and/or rear speaker system is based on the ambient noise level.

Claims

1. A method for a vehicle to warn pedestrians, comprising:

estimating an ambient noise level proximate the vehicle;

generating a warning sound external to the vehicle based on a signal from a pedestrian detection sensor wherein at least one of an intensity or a frequency of the warning sound is based on the ambient noise level.

2. The method of claim 1 wherein the pedestrian detection sensor is one of a LIDAR, radio frequency, and sonic detector.

3. The method of claim 1, further comprising:

processing the signal from the pedestrian detection sensor to determine whether a pedestrian-shaped object is proximate the vehicle wherein the warning sound is based on such determination of a pedestrian-shaped object being proximate the vehicle.

4. The method of claim 3, further comprising:

processing the signal from the pedestrian detection sensor to further determine a distance and location of the pedestrian-shaped object with respect to the vehicle.

5. The method of claim 1 wherein estimating ambient noise level comprises:

estimating a total noise level based on a signal from a vehicle-mounted microphone;

estimating a vehicle noise level based on at least one of vehicle speed, vehicle trajectory, and vehicle accessory activity; and

basing the estimated ambient noise level on total noise level minus vehicle noise level.

6. The method of claim 5 wherein the vehicle accessory comprises at least one of a fan, a pump, and a compressor.

7. The method of claim 1 wherein the warning sound comprises a sound recording including at least one of:

white noise, vehicle accessory noise, vehicle aerodynamic noise, engine noise, and vehicle road noise.

8. The method of claim 1, further comprising:

determining a direction in which the vehicle is moving;

emitting the warning sound directed toward the front of the vehicle when the vehicle is moving forward; and

emitting the warning sound directed behind the vehicle when the vehicle is moving in reverse.

9. The method of claim 3, further comprising:

estimating a distance between the vehicle and the pedestrian-sized object wherein the intensity of the warning sound is further based on the distance between the vehicle and the pedestrian-sized object;

estimating a vehicle speed wherein the intensity of the warning sound is further based on the vehicle speed with intensity increasing as vehicle speed increases; and

focusing the warning sound more tightly when vehicle speed increases.

10. The method of claim 1 wherein the vehicle is a hybrid electric vehicle and the generating the warning sound is further based on the vehicle being propelled by electric power only.

11. The method of claim 1 wherein the generating the warning sound is further based on a speed of the vehicle being greater than a first threshold and less than a second threshold.

12. A system mounted on a vehicle to warn pedestrians, comprising:

a speaker system;

a microphone;

a pedestrian detector; and

an electronic control unit (ECU) electronically coupled to the speaker system, the microphone, and the pedestrian detector, the ECU commanding the speaker system to emit a warning sound based on a signal from the pedestrian detector and a signal from the microphone.

13. The system of claim 12 wherein the vehicle is configured to be propelled exclusively under electric power during certain intervals and the ECU commands the speaker system to emit the warning sound further based on the vehicle being propelled exclusively under electric power.

14. The system of claim 12 wherein the ECU estimates an ambient noise level based on the signal from the microphone and the warning sound intensity commanded to the speaker system is further based on the estimated ambient noise level at a range of frequencies.

15. The system of claim 14 wherein the warning sound intensity and frequency commanded to the speaker system is based on the ambient noise frequencies detected and their respective intensities.

16. A pedestrian warning system mounted on a vehicle configured to be propelled under electric power, comprising:

a front speaker system;

a rear speaker system;

a front pedestrian detector;

a rear pedestrian detector; and

an electronic control unit (ECU) electronically coupled to the front speaker system, the rear speaker system, the front pedestrian detector and the rear pedestrian detector wherein;

the ECU commands the front speaker system to emit a warning sound based on the front pedestrian detector detecting a pedestrian-shaped object; and

the ECU commands the rear speaker system to emit a warning sound based on the rear pedestrian detector detecting a pedestrian-shaped object.

17. The pedestrian warning system of claim 16, further comprising:

a microphone electronically coupled to the ECU, wherein the ECU estimates an ambient noise level based on a signal from the microphone, the ECU commands one of the front speaker system and the rear speaker system to emit the warning sound further based on the estimated ambient noise level with the warning sound intensity being based on the estimated ambient noise level.

18. The system of claim 16 wherein the warning sound emitted by the front speaker system is more intense in the front of the vehicle than in other directions;

the warning sound emitted by the rear speaker system is more intense in the rear of the vehicle than in other directions;

the warning sound is more focused as vehicle speed increases; and

the warning sound is less focused as vehicle speed decreases.

19. The system of claim 16, further comprising:

a vehicle sensor from which trajectory of the vehicle is estimated wherein when the vehicle trajectory is toward the right, the warning sound from the speaker system is biased toward the right and when the vehicle trajectory is toward the left, the warning sound from the speaker system is biased toward the left.

20. The system of claim 16 wherein the warning sound is a recorded sound and is at least one of vehicle accessory noise, vehicle aerodynamic noise, engine noise, and vehicle road noise.

21. The system of claim 16, further comprising:

front head lights coupled to the ECU; and

tail lights coupled to the ECU wherein the ECU commands the front headlight to flash based on the front pedestrian detector detecting a pedestrian-shaped object and commands the tail lights to flash based on the rear pedestrian detector detecting a pedestrian-shaped object.