Automotive Radar Sensor Blockage Detection System and Related Techniques

• US 20090243912A1
• Filed: 03/30/2009
• Published: 10/01/2009
• Est. Priority Date: 03/31/2008
• Status: Active Grant

• Current Assignee: Valeo Radar Systems, Inc. (Valeo SE)
• Original Assignee: Valeo Radar Systems, Inc. (Valeo SE)
• Inventors: Lohmeier, Stephen P., Nguyen, Nguyen D.
• Granted Patent: US 7,973,701 B2
• Time in Patent Office: Days
• 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 2013/93274 on the side of the vehicles
• CPC Class Codes: G01S 7/4004 of parts of a radar system
• CPC Class Codes: G01S 7/4039 of sensor or antenna obstruction, e.g. dirt- or ice-coating
• CPC Class Codes: G01S 7/4056 specially adapted to FMCW
• CPC Class Codes: G01S 7/4091 during normal radar operation

Abstract

A blockage detection system and method for use in a sensor such as a side object detection (SOD) sensor in an automotive radar system is described. The sensor emits signals and receives return signals (i.e. reflected signals) from a passing object. If the passing object is within a virtual detection zone, the sensor uses the information from the passing object to determine if a blockage condition exists in the sensor. The technique utilizes statistics related to the passing object to determine whether a blockage condition exists within the sensor. In one embodiment, a SOD sensor mounted in a first vehicle uses information from a second passing vehicle (e.g. radar return information) to determine whether a blockage condition exists within the SOD sensor itself.

Claims

1. A blockage detection process comprising:

(a) detecting a target within a virtual detection zone;

(b) while the target is within the virtual detection zone, accumulating target-related information;

(c) based upon the information accumulated in (b), determining if a missed alert signal should be generated.

2. The blockage detection process of claim 1 further comprising;

(d) in response to a missed alert signal being generated, recording a time of the miss; and

(e) using the missed alert signals to determine whether a blockage condition exists.

3. The blockage detection process of claim 2 wherein using the missed alert signals to determine whether a blockage condition exists comprises using information related to the frequency with which missed alert signals occur.

4. The blockage detection process of claim 2 wherein using the missed alert signals to determine whether a blockage condition exists comprises determining a pattern of the missed alert signals.

5. The blockage detection process of claim 2 wherein using the missed alert signals to determine whether a blockage condition exists comprises:

collecting information related to characteristics of the missed alert signals; and

applying one or more logical conditions to the information.

6. The method of claim 5 further comprising counting an amount of time between missed alert signals

7. The method of claim 6 further comprising counting an amount of time between missed alert signals wherein counting time between misses comprises at least one of:

counting a number major cycles which occur between misses; and

counting a number of minor cycles which occur between misses.

8. The method of claim 2 further comprising:

in response to a decision being made that a blockage condition exists, generating a blockage alert signal.

9. The method of claim 2 wherein accumulating target-related information comprises accumulating statistics on the target

10. The method of claim 9 wherein accumulating statistics on the target comprises collecting one or more of:

(1) target range;

(2) target range history;

(3) range of closest approach;

(4) point of closest approach;

(5) angle;

(6) angle history;

(7) speed;

(8) amount of time spent by a target in a virtual detection zone;

(9) number of total detections;

(10) raw radar detection count; and

(11) detection density as a function of range and/or angle.

11. A blockage detection system comprising:

a missed alert detection processor configured to receive target data and in response to the target data to generate a missed alert signal; and

a blockage detection determination processor coupled to receive a missed alert signal from said missed alert detection processor and configured to provide a blockage alert signal at an output port thereof.

12. The blockage detection processor of claim 11 wherein said missed alert detection processor comprises:

a virtual detection zone processor configured to determine identify when a target detection occurs in a virtual detection zone;

an accumulator for collecting information related to the object, said accumulator responsive to a signal from said virtual zone detection processor indicating that an object is within the virtual detection zone; and

a missed alert signal generator coupled to receive information from said accumulator, said missed alert signal generator configured to analyze information from said accumulator and to provide a missed alert signal in response to a metric being met

13. The blockage detection processor of claim 12 wherein said accumulator collects one or more of:

(1) target range;

(2) target range history;

(3) range of closest approach;

(4) point of closest approach;

(5) angle;

(6) angle history;

(7) speed;

(8) time spent by a target in a virtual detection zone;

(9) number of total detections;

(10) raw radar detection count; and

(11) detection density as a function of range and/or angle.

14. The blockage detection processor of claim 13 wherein said a blockage detection determination processor provides a blockage alert signal in response to receiving M missed alert signals from said missed alert detection processor within N amount of time.

15. A method for determining a blockage condition in an automotive radar side object detection system, the method comprising:

establishing a virtual detection zone;

emitting signals from the automotive radar side object detection system;

receiving, in the automotive radar side object detection system, a plurality of return signals from a target located in the virtual detection zone; and

processing the plurality of return signals from the target located in the virtual detection zone to determine if a blockage condition exists.

16. The method of claim 15 wherein processing the plurality of return signals from the target located in the virtual detection zone to determine if a blockage condition exists comprises:

generating one or more missed alert signals; and

using the one or more missed alert signals to determine whether a blockage condition exists.

17. The method of claim 15 wherein using the missed alert signals to determine whether a blockage condition exists comprises:

collecting information related to characteristics of the missed alert signals; and

applying one or more logical conditions to the information.