Method for determining object sensor misalignment

• US 8,930,063 B2
• Filed: 02/22/2012
• Issued: 01/06/2015
• Est. Priority Date: 02/22/2012
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations LLC (General Motors Company)
• Inventors: Gandhi, Daniel, Rayarapu, Satish, Feldman, Dmitriy
• Primary Examiner(s): Trammell, James
• Assistant Examiner(s): ALSOMIRI, MAJDI A
• Application Number:
  US13/402,089
• Publication Number:
  US 20130218398A1
• Time in Patent Office: 1,049 Days
• Field of Search: 701/31.1, 701/34, 701/36, 701/96, 701/223, 701/301, 342 69- 73, 342/81, 342/90, 342/95, 342/174, 735/140.1, 180/128, 180167-169
• US Class Current: 701/31.1
• CPC Class Codes: B60R 16/02 electric constitutive elements
• CPC Class Codes: B60W 2050/0088 Adaptive recalibration
• CPC Class Codes: B60W 2050/0215 Sensor drifts or sensor failures
• CPC Class Codes: B60W 2520/14 Yaw
• CPC Class Codes: B60W 2520/28 Wheel speed
• CPC Class Codes: B60W 2540/18 Steering angle
• CPC Class Codes: B60W 50/0205 Diagnosing or detecting failures; Failure detection models
• CPC Class Codes: G01S 13/58 Velocity or trajectory determination systems; Sense-of-movement determination systems
• CPC Class Codes: G01S 13/726 Multiple target tracking
• CPC Class Codes: G01S 13/931 of land vehicles
• CPC Class Codes: G01S 17/58 Velocity or trajectory determination systems; Sense-of-movement determination systems
• CPC Class Codes: G01S 17/66 Tracking systems using electromagnetic waves other than radio waves
• CPC Class Codes: G01S 17/931 of land vehicles
• CPC Class Codes: G01S 2013/9316 combined with communication equipment with other vehicles or with base stations
• CPC Class Codes: G01S 2013/932 using own vehicle data, e.g. ground speed, steering wheel direction
• CPC Class Codes: G01S 2013/9322 using additional data, e.g. driver condition, road state or weather data
• CPC Class Codes: G01S 2013/93271 in the front of the vehicles
• CPC Class Codes: G01S 2013/93272 in the back of the vehicles
• CPC Class Codes: G01S 2013/93274 on the side of the vehicles
• CPC Class Codes: G01S 2013/93275 in the bumper area
• 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 7/4091 : during normal radar operation
• CPC Class Codes: G01S 7/4972 : Alignment of sensor

Abstract

A vehicle system and method that can determine object sensor misalignment while a host vehicle is being driven, and can do so without requiring multiple sensors with overlapping fields-of-view. In an exemplary embodiment where the host vehicle is traveling in generally a straight line, the present method uses an object sensor to track the path of a stationary object as it moves through the sensor'"'"'s field-of-view and compares the sensed object path to an expected object pat*h. If the sensed and expected paths of the stationary object deviate by more than some amount, then the method determines that the object sensor is skewed or otherwise misaligned.

Claims

1. A method for use with an object sensor located on a host vehicle, comprising the steps of:

(a) determining if a sensed object is stationary;

(b) tracking the object with the object sensor as it moves through the object sensor field-of-view so that a sensed object path is established; and

(c) comparing the sensed object path with an expected object path retrieved from a memory device in order to determine if the object sensor is misaligned, wherein the sensed object path is based on readings from the object sensor and the expected object path is based on a known mounting angle of the object sensor.

2. The method of claim 1, wherein step (a) further comprises receiving sensor readings from at least one of a steering angle sensor, a yaw rate sensor, or a wheel speed sensor, and using the sensor readings from at least one of the steering angle sensor, the yaw rate sensor, or the wheel speed sensor and determining if the host vehicle is traveling in a generally straight line.

3. The method of claim 1, wherein step (b) further comprises tracking the object with the object sensor as it moves through the object sensor field-of-view by storing information related to an object entry point and an object exit point.

4. The method of claim 3, wherein the information related to the object entry point includes a time and a position of the object as it enters the object sensor field-of-view and the information related to the object exit point includes a time and a position of the object as it exits the object sensor field-of-view.

5. The method of claim 1, wherein step (b) further comprises tracking the object with the object sensor as it moves through the object sensor field-of-view, and then determining if the object is appropriate for use in evaluating the alignment of the object sensor.

6. The method of claim 5, wherein step (b) further comprises determining if the object is appropriate for use in evaluating the alignment of the object sensor by calculating an object path length for the sensed object path and comparing the object path length to a path length threshold.

7. The method of claim 1, wherein step (a) further comprises determining if the object is stationary by determining an object velocity, determining a host vehicle velocity, and comparing the object velocity to the host vehicle velocity.

8. The method of claim 7, wherein step (a) further comprises determining the object velocity by dividing an object path length by an object path duration.

9. The method of claim 1, wherein step (c) further comprises comparing the sensed object path with the expected object path by determining a sensed object angle (θ

s) that corresponds to the sensed object path and an expected object angle (θ

e) that corresponds to the expected object path, and then comparing these two angles to one another.

10. The method of claim 9, wherein step (c) further comprises determining the difference between the sensed object angle (θ

s) and the expected object angle (θ

e), and comparing the difference to an object angle threshold.

11. The method of claim 1, further comprising the step of:

(d) taking one or more remedial actions when it is determined that the object sensor is misaligned.

12. The method of claim 11, wherein step (d) further comprises sending a warning message to a user interface that informs the driver that the object sensor is misaligned.

13. The method of claim 11, wherein step (d) further comprises sending command signals to a module on the host vehicle that instruct the module to avoid using sensor readings from the misaligned sensor.

14. The method of claim 1, wherein the method determines if the object sensor is misaligned while the host vehicle is being driven in normal operation.

15. The method of claim 1, wherein the method determines if the object sensor is misaligned without the requirement of multiple object sensors with overlapping fields-of-view.

16. The method of claim 1, wherein the method determines if the object sensor is misaligned without the requirement that the object sensor be able to internally calculate and provide the velocity of a sensed object.

17. A method for use with an object sensor located on a host vehicle, comprising the steps of:

(a) determining if the host vehicle is traveling in a generally straight line;

(b) when the host vehicle is traveling in a generally straight line, tracking an object with the object sensor by determining an object entry point where the object enters an object sensor field-of-view and an object exit point where the object exits the object sensor field-of-view;

(c) using the object entry point and the object exit point to determine if the object is stationary;

(d) when the object is stationary, evaluating a sensed object path that extends from the object entry point to the object exit point by determining a sensed object angle (θ

s) corresponding to the sensed object path and an expected object angle (θ

e) corresponding to an expected object path; and

(e) using the sensed object angle (θ

s) and the expected object angle (θ

e) to determine if the object sensor is misaligned.

18. A vehicle system on a host vehicle, comprising:

one or more vehicle sensors providing sensor readings, the vehicle sensor readings indicate whether or not the host vehicle is traveling in a generally straight line;

one or more object sensors providing sensor readings, the object sensor readings establish a sensed object path for an object as it moves through an object sensor field-of-view; and

a control module having a memory device, the control module being coupled to the one or more vehicle sensors for receiving the vehicle sensor readings and being coupled to the one or more object sensors for receiving the object sensor readings, wherein the control module is configured to compare the sensed object path with an expected object path based on a known mounting angle of the object sensor stored in the memory device in order to determine if the object sensor is misaligned when the host vehicle is traveling in a generally straight line and the object is stationary.