Automotive radar sensor blockage detection system and related techniques

• US 7,973,701 B2
• Filed: 03/30/2009
• Issued: 07/05/2011
• 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.
• Primary Examiner(s): Tarcza; Thomas H
• Assistant Examiner(s): Brainard; Timothy A
• Application Number:
  US12/414,227
• Publication Number:
  US 20090243912A1
• Time in Patent Office: 827 Days
• Field of Search: 342/70
• US Class Current: 342/89
• 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 system comprising:

a missed alert detection processor configured to receive target data generated in a virtual detection zone of the blockage detection system, 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.

2. The blockage detection processor of claim 1 wherein said missed alert detection processor comprises:

a virtual detection zone processor configured to determine when a target detection occurs in the 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.

3. The blockage detection processor of claim 2 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.

4. The blockage detection processor of claim 3 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.