Detecting radar blockage based on drive history

• US 9,453,910 B2
• Filed: 04/23/2014
• Issued: 09/27/2016
• Est. Priority Date: 04/23/2014
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Elwart, Shane, Mills, Aaron L., Spero, Dorian Jack
• Primary Examiner(s): Brainard, Timothy A
• Application Number:
  US14/259,422
• Publication Number:
  US 20150309165A1
• Time in Patent Office: 888 Days
• Field of Search: 342/61
• US Class Current: 1/1
• CPC Class Codes: G01S 13/02 Systems using reflection of radio waves, e.g. primary radar systems; Analogous systems
• CPC Class Codes: G01S 13/867 Combination of radar systems with cameras
• CPC Class Codes: G01S 13/931 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 7/4026 Antenna boresight
• CPC Class Codes: G01S 7/4039 of sensor or antenna obstruction, e.g. dirt- or ice-coating

Abstract

A vehicle includes a radar sensor for detecting objects in the vehicle path. The radar sensor may become blocked by contaminants or debris. A controller monitoring the radar system may detect a radar blockage when a return signal magnitude is less than a threshold. A typical response may be to set a radar blockage diagnostic under such a condition. The controller may inhibit setting a radar blockage diagnostic when other data indicates that the radar sensor is not blocked. Data such as vehicle position, traffic information, camera images, and historical radar returns may be used. A controller may confirm a radar blockage diagnostic when other data indicates that the radar sensor may be blocked. Data such as temperature, vehicle position, surface roughness, automated brake interventions, and heating system status may be used. Return signal dependent functions may be operated based on the radar blockage diagnostic.

Claims

1. A vehicle comprising:

a sensor configured to output a return signal based on a reflected signal from an external object; and

at least one controller configured to, (i) output an unblocked confirmed sensor status in response to a magnitude of the return signal being greater than a predetermined value, (ii) output a blocked confirmed sensor status in response to the magnitude being less than the predetermined value in a presence of data indicative of conditions in which the magnitude is expected to be greater than the predetermined value, and (iii) output an unblocked unconfirmed sensor status in response to the magnitude being less than the predetermined value in the presence of data indicative of conditions in which the magnitude is expected to be less than the predetermined value.

2. The vehicle of claim 1 wherein the at least one controller is further programmed to, (i) in response to outputting the unblocked confirmed sensor status, operate a function dependent on the return signal in a full operation mode, (ii) in response to outputting the blocked confirmed sensor status, operate the function in a disabled mode, and (iii) in response to outputting the unblocked unconfirmed sensor status, operate the function in one of a partial operation mode, the full operation mode and the disabled mode.

3. The vehicle of claim 2 wherein the function is a collision warning function, and wherein the collision warning function is operated in the partial operation mode by increasing a detection threshold for external objects.

4. The vehicle of claim 1 wherein the magnitude is expected to be less than the predetermined value when a sparse environment is detected in which the vehicle is operating in an absence of external objects to cause the magnitude of the return signal to be greater than the predetermined value.

5. The vehicle of claim 4 wherein data indicative of conditions in which the magnitude is expected to be less than the predetermined value includes one or more of a vehicle position, traffic information, images from a camera, and historical return signal signatures.

6. The vehicle of claim 1 wherein of data indicative of conditions in which the magnitude is expected to be greater than the predetermined value includes one or more of a temperature, a defroster status, a heater status, a braking control intervention signal, a surface roughness, a braking event indication, images from a camera, and a vehicle position.

7. An external object detection system for a vehicle comprising:

a sensor configured to provide a return signal based on a reflected signal from an object; and

at least one controller programmed to output an unblocked unconfirmed sensor status in response to conditions indicative of an expected return signal magnitude being less than a predetermined value while an actual return signal magnitude is less than the predetermined value.

8. The external object detection system of claim 7 wherein the at least one controller is further programmed to receive vehicle location data, and wherein conditions indicative of the expected return signal magnitude being less than the predetermined value includes a historical return signal signature less than the predetermined value at a present vehicle location.

9. The external object detection system of claim 8 wherein the at least one controller is further programmed to receive traffic information, and wherein conditions indicative of the expected return signal magnitude being less than the predetermined value includes traffic information that indicates a sparse environment at the present vehicle location.

10. The external object detection system of claim 7 further comprising a camera, and wherein the at least one controller is further programmed to receive images from the camera, and wherein conditions indicative of the expected return signal magnitude being less than the predetermined value includes an absence of objects expected to cause the actual return signal magnitude to be greater than the predetermined value in images received from the camera.

11. The external object detection system of claim 7 wherein the at least one controller is further programmed to output a blocked confirmed sensor status in response to conditions indicative of a presence of one or more of ice and snow while the actual return signal magnitude is less than the predetermined value.

12. The external object detection system of claim 7 wherein the at least one controller is further programmed to output a blocked confirmed sensor status in response to conditions indicative of the expected return magnitude being greater than the predetermined value while the actual return signal magnitude is less than the predetermined value.

13. The external object detection system of claim 12 wherein the at least one controller is further programmed to receive brake control intervention information, and wherein conditions indicative of the expected return magnitude being greater than the predetermined value includes an increase in a frequency of brake control intervention events.

14. The external object detection system of claim 12 wherein the at least one controller is further programmed to receive vehicle location data, and wherein conditions indicative of the expected return magnitude being greater than the predetermined value includes braking events in a historically sparse area based on a vehicle location.

15. The external object detection system of claim 12 further comprising a camera, and wherein the at least one controller is further programmed to receive images from the camera, wherein conditions indicative of the expected return magnitude being greater than the predetermined value includes ice and snow in images received from the camera.

16. The external object detection system of claim 12 wherein the at least one controller is further programmed to receive surface roughness information, wherein conditions indicative of the expected return magnitude being greater than the predetermined value includes a change in surface roughness.

17. A method of detecting an object detection sensor blockage comprising:

receiving a return signal based on a reflected signal from an external object;

receiving data indicative of an expected return signal magnitude;

inhibiting, by a controller, a sensor blockage diagnostic indication in response to an actual return signal magnitude and the expected return signal magnitude both being less than a predetermined value; and

outputting, by the controller, the sensor blockage diagnostic indication in response to the actual return signal magnitude being less than the predetermined value and the expected return signal magnitude being greater than the predetermined value.

18. The method of claim 17 further comprising operating return signal dependent functions based on a present status of the sensor blockage diagnostic.

19. The method of claim 17 further comprising indicating the sensor blockage diagnostic to an operator.