System and method for detecting obstructions and misalignment of ground vehicle radar systems

• US 8,441,394 B2
• Filed: 07/11/2011
• Issued: 05/14/2013
• Est. Priority Date: 07/11/2011
• Status: Active Grant

• Current Assignee: Aptiv Technologies AG (Aptiv PLC)
• Original Assignee: Delphi Technologies, Inc. (Aptiv PLC)
• Inventors: Alland, Stephen W.
• Primary Examiner(s): Sotomayor, John B
• Application Number:
  US13/179,716
• Publication Number:
  US 20130015999A1
• Time in Patent Office: 673 Days
• Field of Search: 342 70- 72, 340435-436, 340/903, 701/301
• US Class Current: 342/70
• CPC Class Codes: G01S 13/931 of land vehicles
• CPC Class Codes: G01S 2013/9315 Monitoring blind spots
• CPC Class Codes: G01S 2013/932 using own vehicle data, e.g. ground speed, steering wheel direction
• CPC Class Codes: G01S 2013/93275 in the bumper area
• CPC Class Codes: G01S 7/4026 Antenna boresight
• CPC Class Codes: G01S 7/4034 in elevation, i.e. in the vertical plane
• CPC Class Codes: G01S 7/4039 of sensor or antenna obstruction, e.g. dirt- or ice-coating
• CPC Class Codes: G01S 7/4091 during normal radar operation

Abstract

A system, controller, antenna, and method for detecting obstruction and misalignment of a ground vehicle radar having an antenna configured to detect objects in a first direction characterized as being substantially parallel to a horizontal plane about the ground vehicle, and detect objects in a second direction characterized as being toward a roadway surface proximate to the ground vehicle. The second direction radar return from the roadway is expected to have certain characteristics. If the characteristics are outside of a predetermined window, then obstruction and/or misalignment of the first direction and the second direction is likely, and so the radar may not reliably detect an object in the first direction, such as a vehicle in an adjacent lane.

Claims

1. A ground vehicle radar system configured to be installed on a ground vehicle, said system comprising:

an antenna configured to be installed at an antenna location on the ground vehicle for detecting objects about the ground vehicle, said antenna configured to detect objects in a first direction characterized as being substantially parallel to a horizontal plane about the ground vehicle, and detect objects in a second direction characterized as being toward a location on a roadway surface proximate to the ground vehicle; and

a controller configured to be coupled to the antenna effective to receive a first antenna signal indicative of a first radar reflection from an object located in the first direction, and a second antenna signal indicative of a second radar reflection from an object located in the second direction, wherein said controller is further configured to determine when the first direction is blocked by an obstruction proximate to the antenna location based on the second antenna signal, wherein said controller is further configured to determine a first signal absorption factor of an obstruction based on a second signal amplitude.

2. The system in accordance with claim 1, wherein said antenna comprises

a first receive element configured to receive a first radar reflection from the first direction;

and

a second receive element configured to receive a second radar reflection from the second direction.

3. The system in accordance with claim 1, wherein the controller is further configured to determine a vertical alignment angle of the first direction based on the second antenna signal.

4. The system in accordance with claim 3, wherein said vertical alignment angle is determined based on a difference between the second antenna signal and an expected antenna signal.

5. The system in accordance with claim 1, wherein the controller is further configured to determine a vertical alignment angle of the first direction based on the second antenna signal and a vehicle speed.

6. The system in accordance with claim 5, wherein the controller is further configured to determine the vehicle speed based on the first antenna signal.

7. A controller for ground vehicle radar system, said controller comprising:

a first input configured to receive a first antenna signal indicative of a first radar reflection from a first direction characterized as being substantially parallel to a horizontal plane about the ground vehicle;

a second input configured to receive a second antenna signal indicative of the second radar reflection from a second direction characterized as being from a location on a roadway surface proximate to the ground vehicle; and

a processor configured to determine that the first direction is blocked by an obstruction proximate to the antenna location based on the second antenna signal, wherein said processor is further configured to determine a first signal absorption factor of an obstruction based on a second signal amplitude.

8. The controller in accordance with claim 7, wherein said controller further comprises

a first output configured to output a first transmit signal for emitting electromagnetic energy in the first direction;

and

a second output configured to output a second transmit signal for emitting electromagnetic energy in the second direction.

9. The controller in accordance with claim 7, wherein the processor is further configured to determine a vertical alignment angle of the first direction based on the second antenna signal and a vehicle speed.

10. The controller in accordance with claim 9, wherein the processor is further configured to determine the vehicle speed based on the first antenna signal.

11. A method of operating a ground vehicle radar system, said method comprising:

providing an antenna configured to be installed at an antenna location on a ground vehicle for detecting objects about the ground vehicle, said antenna configured to detect objects in a first direction characterized as being substantially parallel to a horizontal plane about the ground vehicle, and detect objects in a second direction characterized as being toward a location on a roadway surface proximate to the ground vehicle;

receiving a first antenna signal;

receiving a second antenna signal; and

determining when the first direction is blocked by an obstruction proximate to the antenna location based on the second antenna signal, wherein the step of determining when the first direction is blocked includes determining a first signal absorption factor of an obstruction based on a second signal amplitude.

12. The method in accordance with claim 11, said method further comprising determining a vertical alignment angle for the first direction based on the second antenna signal and a vehicle speed.

13. The method in accordance with claim 12, wherein the step of determining the vertical alignment angle includes determining a difference between the second antenna signal and an expected antenna signal.

14. The method in accordance with claim 12, wherein the step of determining the vehicle speed is based on the first antenna signal.