Sensing misalignment detection and estimation system

• US 20080201033A1
• Filed: 02/21/2007
• Published: 08/21/2008
• Est. Priority Date: 02/21/2007
• Status: Active Grant

• Current Assignee: Arriver Software LLC (Qualcomm, Inc.)
• Original Assignee: Autoliv ASP Incorporated (Autoliv Incorporated)
• Inventors: Lee, Kangwon, DeMersseman, Bernard
• Granted Patent: US 7,813,851 B2
• Time in Patent Office: Days
• US Class Current: 701/29
• CPC Class Codes: B60W 2420/408 Radar; Laser, e.g. lidar
• CPC Class Codes: B60W 40/107 Longitudinal acceleration
• CPC Class Codes: B60W 40/109 Lateral acceleration
• CPC Class Codes: G01B 21/24 for testing alignment of axes
• CPC Class Codes: G01S 13/86 Combinations of radar systems with non-radar systems, e.g. sonar, direction finder
• CPC Class Codes: G01S 13/931 of land vehicles
• CPC Class Codes: G01S 2013/932 using own vehicle data, e.g. ground speed, steering wheel direction
• CPC Class Codes: G01S 2013/93271 in the front of the vehicles
• CPC Class Codes: G01S 7/4026 Antenna boresight
• CPC Class Codes: G01S 7/403 in azimuth, i.e. in the horizontal plane
• CPC Class Codes: G01S 7/4034 in elevation, i.e. in the vertical plane
• CPC Class Codes: G01S 7/4091 during normal radar operation

Abstract

A misalignment detection sensor assembly is provided, which includes a forward-looking sensor having a sensing direction along a first axis and an inertia sensor configured to sense acceleration along a second axis, the second axis having a fixed relationship with respect to the first axis. A misalignment detection system uses the misalignment detection sensor assembly and a signal processing system to calculate a misalignment angle between the first axis and the direction of forward motion of the sensor assembly. A method of detecting angular misalignment of a forward-looking sensor assembly is also disclosed, which includes measuring acceleration along an axis having a fixed relationship with respect to the sensing axis of the forward-looking sensor assembly and comparing the acceleration measurement with a predetermined threshold.

Claims

1. A misalignment detection sensor assembly for a motor vehicle comprising:

a forward-looking sensor package having a housing and a forward-looking sensor, the forward-looking sensor having a sensing direction along a first axis; and

an inertia sensor fixed to the housing, the inertia sensor configured to sense acceleration along a second axis, the second axis having a fixed, non-parallel relationship with respect to the first axis.

2. The misalignment detection sensor assembly of claim 1, wherein the second axis is orthogonal to the first axis.

3. The misalignment detection sensor assembly of claim 1, wherein the inertia sensor is further configured to sense acceleration along a third axis, the third axis being orthogonal to the second axis.

4. The misalignment detection sensor assembly of claim 3, wherein the third axis is parallel to the first axis.

5. The misalignment detection sensor assembly of claim 3, wherein the second axis is orthogonal to the first axis, and the third axis is orthogonal to the first axis.

6. The misalignment detection sensor assembly of claim 3, wherein the second axis extends in a direction about 45 degrees from the direction of the first axis.

7. The misalignment detection sensor assembly of claim 1, further comprising a signal processor in electrical communication with the forward looking sensor and the inertia sensor, the signal processor being configured to receive an acceleration signal from the inertia sensor, the signal being further configured to calculate a misalignment angle between the first axis and a forward axis, the forward axis being parallel to a direction of motion of the sensor assembly.

8. The misalignment detection sensor assembly of claim 7, wherein the signal processing system is further configured to produce an alert signal when the misalignment angle exceeds a predetermined threshold.

9. The misalignment detection sensor assembly of claim 7, wherein the signal processing system is further configured to compensate a sensitive measurement of the forward-looking sensor based upon the misalignment angle.

10. The misalignment detection sensor assembly of claim 1, wherein the forward-looking sensor is a radar sensor.

11. The misalignment detection sensory assembly of claim 1, further comprising a second inertia sensor, the second inertia sensor being operable to sense acceleration along a third axis.

12. A misalignment detection system comprising:

a sensor assembly comprising;

a forward-looking sensor package having a housing and a forward-looking sensor, the forward-looking sensor having a sensing direction along a first axis; and

an inertia sensor fixed to the housing, the inertia sensor configured to sense acceleration along a second axis, the second axis having a fixed, non-parallel relationship with respect to the first axis; and

a signal processing system configured to receive an acceleration signal from the inertia sensor and calculate a misalignment angle between the first axis and a forward axis, the forward axis being parallel to a direction of motion of the sensor assembly.

13. The misalignment detection system of claim 12, wherein the signal processing system is further configured to produce an alert signal when the misalignment angle exceeds a predetermined threshold.

14. The misalignment detection system of claim 12, wherein the signal processing system is further configured to compensate a sensitive measurement of the forward-looking sensor based upon the misalignment angle.

15. The misalignment detection sensor assembly of claim 12, wherein the second axis is orthogonal to the first axis.

16. The misalignment detection sensor assembly of claim 12, wherein the inertia sensor is further configured to sense acceleration along a third axis, the third axis being orthogonal to the second axis.

17. The misalignment detection sensor assembly of claim 16, wherein the third axis is parallel to the first axis.

18. The misalignment detection sensor assembly of claim 16, wherein the second axis is orthogonal to the first axis, and the third axis is orthogonal to the first axis.

19. The misalignment detection sensor assembly of claim 16, wherein the second axis extends in a direction about 45 degrees,from the direction of the first axis.

20. The misalignment detection system of claim 12, wherein the signal processing system is further configured to determine whether a motor vehicle to which the sensor assembly is attached is traveling in a straight, forward direction.

21. A method of detecting angular misalignment of a forward-looking sensor assembly, comprising:

measuring acceleration along a first axis and outputting a first acceleration signal, the first axis having a predetermined relationship with respect to a second axis, the second axis extending along a sensing direction of a forward-looking sensor; and

determining whether the second axis is substantially parallel with a forward axis, the forward axis extending along a direction of motion of the forward-looking sensor assembly using a method comprising;

determining the value of the first acceleration signal; and

comparing the value of the first acceleration signal with a predetermined threshold.

22. The method of claim 21, further comprising calculating a misalignment angle between the forward axis and the second axis.

23. The method of claim 22, further comprising comparing the value of the misalignment angle to a predetermined threshold.

24. The method of claim 23, further comprising producing an alert signal if the misalignment angle exceeds the predetermined threshold.

25. The method of claim 23, further comprising compensating a sensitive measurement of the forward-looking sensor assembly if the misalignment angle exceeds the predetermined threshold.

26. The method of claim 21, further comprising:

measuring acceleration along a third axis and outputting a second acceleration signal, the third axis having a predetermined relationship with respect to the first and second axes; and

calculating a misalignment angle between the forward axis and the second axis based on the first and second acceleration signals.

27. The method of claim 21, further comprising determining whether a motor vehicle to which the forward-looking sensor assembly is attached is traveling in a straight, forward direction.