Thermal radiation detector

• US 20090189752A1
• Filed: 01/25/2008
• Published: 07/30/2009
• Est. Priority Date: 01/25/2008
• Status: Active Grant

• Current Assignee: Aptiv Technologies AG
• Original Assignee: Delphi Technologies, Inc. (BorgWarner Incorporated)
• Inventors: Taylor, Ronald M.
• Granted Patent: US 7,876,204 B2
• Time in Patent Office: Days
• US Class Current: 340/435
• CPC Class Codes: G01J 5/0022 for sensing the radiation of moving bodies
• CPC Class Codes: G01J 5/07 Arrangements for adjusting the solid angle of collected radiation, e.g. adjusting or orienting field of view, tracking position or encoding angular position optical collimating elements G01J5/0806
• CPC Class Codes: G01J 5/08 Optical arrangements
• CPC Class Codes: G01J 5/0806 Focusing or collimating elements, e.g. lenses or concave mirrors
• CPC Class Codes: G01J 5/0893 Arrangements to attach devices to a pyrometer, i.e. attaching an optical interface; Spatial relative arrangement of optical elements, e.g. folded beam path G01J5/049 takes precedence
• CPC Class Codes: G08G 1/166 for active traffic, e.g. moving vehicles, pedestrians, bikes
• CPC Class Codes: G08G 1/167 Driving aids for lane monitoring, lane changing, e.g. blind spot detection

Abstract

An object detection system is provided for detecting a thermal emitting object in a blind zone proximate to a host vehicle. The system includes a thermal radiation detector located on a host vehicle and configured to sense temperature of multiple coverage zones proximate to the host vehicle. A processor processes temperature sensed by an infrared detector. The processor determines a change in thermal temperature sensed by the infrared detector and determines the presence of an object in the coverage zone based on the change in the sensed temperature. An output provides a signal indicative of an object sensed in the coverage zone based on the determined change in temperature. The thermal radiation detector may include a first infrared detector configured to measure temperature of a first coverage zone by receiving infrared radiation from the first coverage zone, and a second infrared detector configured to measure temperature of second and third coverage zones by receiving infrared radiation from the second and third coverage zones.

Claims

1. A thermal radiation detector for sensing thermal energy in multiple coincident zones relative to a host vehicle, said detector comprising:

a first infrared sensor configured to sense temperature of a first coverage zone by receiving thermal radiation from the first coverage zone;

a second infrared sensor configured to sense temperature of second and third coverage zones by receiving thermal radiation from the second and third coverage zones;

first focusing optics for directing the thermal radiation from the first coverage zone towards the first infrared sensor;

second focusing optics for directing the thermal radiation from the second coverage zone towards the second infrared sensor; and

third focusing optics for directing thermal radiation from the third coverage zone towards the second infrared sensor, wherein the temperature of the first, second and third coverage zones is coincidentally sensed.

2. The detector as defined in claim 1, wherein the first focusing optics comprises a first reflector surface, the second focusing optics comprises a second reflector surface, and the third focusing optics comprises a third reflector surface.

3. The detector as defined in claim 2, wherein the first, second and third reflector surfaces are provided by a compound reflector.

4. The detector as defined in claim 1, wherein the detector further comprises a housing substantially containing the first infrared sensor, the second infrared sensor, the first focusing optics, the second focusing optics and the third focusing optics.

5. The detector as defined in claim 4, wherein the detector is located onboard a host vehicle to sense one or more objects in a blind spot of the host vehicle.

6. The detector as defined in claim 5, wherein the housing is located within the tail lamp assembly of the host vehicle.

7. The detector as defined in claim 1, wherein the first and second infrared sensors are infrared thermopiles.

8. The detector as defined in claim 1, wherein the detector is configured to determine a temperature differential within the first coverage zone and a temperature differential within the second and third coverage zones.

9. The detector as defined in claim 1 further comprises a third infrared sensor configured to sense temperature of a fourth coverage zone by receiving thermal radiation from the fourth coverage zone.

10. A method of detecting a thermal emitting object proximate to a host vehicle, said method comprising the steps of:

directing thermal energy from a first coverage zone proximate to a host vehicle to a first infrared sensor;

sensing temperature of the first coverage zone proximate to the vehicle with the first infrared sensor;

directing thermal energy from a second coverage zone proximate to the host vehicle to a second infrared sensor;

directing thermal energy from a third coverage zone proximate to the host vehicle to the second infrared sensor;

sensing temperature of the second and third coverage zones with the second infrared sensor; and

determining the presence of a thermal emitting object proximate to the vehicle based on coincidentally sensed temperatures of the first, second and third coverage zones.

11. The method as defined in claim 10, wherein the steps of directing thermal energy from the first and second sensors comprises directing thermal energy from the first coverage zone towards the first infrared sensor with first focusing optics, directing thermal radiation from the second coverage zone to the second infrared sensor with second focusing optics, and directing thermal energy from the third coverage zone to the second infrared sensor with third focusing optics.

12. The method as defined in claim 10, wherein the first, second and third focusing optics comprises first, second and third reflector surfaces, respectively.

13. The method as defined in claim 12, wherein the first, second and third reflector surfaces is implemented as a compound reflector.

14. The method as defined in claim 10, wherein the first and second infrared sensors are located on board the host vehicle to sense one or more objects in a blind spot of the host vehicle.

15. The method as defined in claim 14, wherein the first and second infrared sensors are located within a tail lamp assembly of the host vehicle.

16. The method as defined in claim 10, wherein the first and second infrared sensors comprise first and second infrared thermopiles.

17. The method as defined in claim 10, wherein the step of determining presence of a thermal emitting object comprises determining a temperature differential within the first coverage zone and a temperature differential within the second and third coverage zones, wherein an object is detected within a corresponding coverage zone when the temperature differential for that zone exceeds a threshold.