Arrangement and Method for Obtaining Information Using Phase Difference of Modulated Illumination

• US 20070135984A1
• Filed: 11/09/2006
• Published: 06/14/2007
• Est. Priority Date: 05/05/1992
• Status: Active Grant

• Current Assignee: American Vehicular Sciences LLC (Acacia Research Corporation)
• Original Assignee: Automotive Technologies International Incorporated
• Inventors: Breed, David, DuVall, Wilbur, Johnson, Wendell
• Granted Patent: US 7,831,358 B2
• Time in Patent Office: Days
• US Class Current: 701/45
• CPC Class Codes: B60R 21/01516 using force or pressure sensing means
• CPC Class Codes: B60R 21/0152 using strain gauges
• CPC Class Codes: B60R 21/0153 using field detection presence sensors
• CPC Class Codes: B60R 21/01542 detecting passenger motion
• CPC Class Codes: E05F 15/73 responsive to movement or presence of persons or objects
• CPC Class Codes: E05Y 2900/50 for vehicles

Abstract

Land-based vehicle including an arrangement for monitoring objects in or about a vehicle includes a source from which modulated illumination is emitted into an area in or about the vehicle, a receiver arranged to receive illumination reflected from an object in the path of the modulated illumination, and circuitry coupled to the receiver and the source and arranged to compare a phase of the modulated illumination with a phase of the reflected radiation at a common frequency to determine whether there is a phase difference between the modulated illumination and the reflected illumination. The phase difference is a measure of a property of the object, such as the distance between the object and the source/receiver, which can be co-located. Otherwise, if the source and receiver and not co-located or substantially co-located, the distance is a measure of the distance of travel of the illumination.

Claims

1. A land-based vehicle including an arrangement for monitoring objects in or about a vehicle, comprising:

a source from which modulated illumination is emitted into an area in or about the vehicle;

a receiver arranged to receive illumination reflected from an object in the path of the modulated illumination; and

circuitry coupled to said receiver and said source and arranged to compare a phase of the modulated illumination with a phase of the reflected radiation at a common frequency to determine whether there is a phase difference between the modulated illumination and the reflected illumination, whereby said phase difference is a measure of a property of the object.

2. The vehicle of claim 1, wherein said phase difference is a measure of the distance between the object and said receiver and said source.

3. The vehicle of claim 1, wherein said source is a source of infrared radiation.

4. The vehicle of claim 1, wherein said source is a modulated laser.

5. The vehicle of claim 1, wherein said source is arranged such that the modulated illumination is directed into a compartment of the vehicle.

6. The vehicle of claim 1, wherein said source and said receiver are co-located.

7. The vehicle of claim 1, further comprising an occupant protection device arranged to protect an occupant of the vehicle in the event of a crash involving the vehicle, said occupant protection device being coupled to said circuitry and being controlled based on the property of the object.

8. The vehicle of claim 7, wherein said phase difference is a measure of the distance between the object and said receiver and said source, said occupant protection device being controlled based on the distance between the object and said receiver and said source.

9. The vehicle of claim 8, wherein said circuitry is arranged to determine a velocity of the object using multiple determinations of the distance and time differences, said occupant protection device being controlled based on the velocity of the object.

10. A method for monitoring objects in or about a land-based vehicle, comprising:

emitting modulated illumination from a location on the vehicle into an area in or about the vehicle;

receiving illumination reflected from an object in the path of the modulated illumination at a location on the vehicle; and

comparing a phase of the modulated illumination with a phase of the reflected radiation at a common frequency to determine whether there is a phase difference between the modulated illumination and the reflected illumination, whereby the phase difference is a measure of a property of the object.

11. The method of claim 10, wherein the phase difference is a measure of the distance between the object and the location on the vehicle from which the illumination is emitted and at which the reflected illumination is received.

12. The method of claim 10, further comprising arranging an infrared illumination source to emit the modulated illumination into a compartment of the vehicle.

13. The method of claim 12, further comprising co-locating the source and a receiver at which the reflected illumination is received.

14. The method of claim 10, further comprising controlling an occupant protection device which protects an occupant of the vehicle in the event of a crash involving the vehicle based on the property of the object.

15. The method of claim 14, wherein the phase difference is a measure of the distance between the object and the location on the vehicle from which the illumination is emitted and at which the reflected illumination is received, the occupant protection device being controlled based on the distance between the object and the location on the vehicle from which the illumination is emitted and at which the reflected illumination is received.

16. The method of claim 15, further comprising:

determining a velocity of the object using multiple determinations of the distance and time differences; and

controlling the occupant protection device based on the velocity of the object.

17. A method for controlling an occupant protection device in a vehicle which protects an occupant of the vehicle in the event of a crash involving the vehicle, comprising:

emitting modulated illumination from a location on the vehicle into an area in or about the vehicle;

receiving illumination reflected from an object in the path of the modulated illumination at a location on the vehicle;

comparing a phase of the modulated illumination with a phase of the reflected radiation at a common frequency to determine whether there is a phase difference between the modulated illumination and the reflected illumination;

deriving a distance between the object and a location on the vehicle from which the illumination is emitted and at which the reflected illumination is received; and

controlling the occupant protection device based on the derived distance.

18. The method of claim 17, further comprising arranging an infrared illumination source to emit the modulated illumination into a compartment of the vehicle.

19. The method of claim 18, further comprising co-locating the source and a receiver at which the reflected illumination is received.

20. The method of claim 17, further comprising:

determining a velocity of the object using multiple derivations of the distance and time differences; and

controlling the occupant protection device based on the velocity of the object.