Apparatus and method for detecting and correcting for blockage of an automotive radar sensor

1. An automotive radar system, comprising:

a radar transmitter for transmitting a plurality of radar signals into a region;

a radar detector for detecting reflected radar signals and converting the reflected radar signals into digital data signals; and

a processor that receives the digital data signals, generates a plurality of range-Doppler maps for the region over time and averages the plurality of range-Doppler maps to generate an averaged range-Doppler map for the region; wherein

the processor analyzes data points in the averaged range-Doppler map to detect blobs in the averaged range Doppler map; and wherein

if a blob is detected in the averaged range-Doppler map by the processor, the radar detector is indicated by the processor to be unblocked.

2. The automotive radar system of claim 1 , wherein, if a blob is not detected in the averaged range-Doppler map by the processor, the radar detector is indicated by the processor to be blocked.

3. The automotive radar system of claim 1 , wherein a blob in the averaged range-Doppler map is considered by the processor to be due to radar returns from an extended object which is stationary with respect to a ground surface in an environment in which the automotive radar system is operating.

4. The automotive radar system of claim 3 , wherein the extended object is a surface of a road on which the host vehicle is traveling.

5. The automotive radar system of claim 3 , wherein the extended object is a curb along a side of a road on which the host vehicle is traveling.

6. The automotive radar system of claim 1 , wherein the plurality of range-Doppler maps comprise 150 range-Doppler maps.

7. The automotive radar system of claim 1 , wherein the radar signals have a frequency of approximately 77 GHz.

8. The automotive radar system of claim 1 , wherein, for each data point in the averaged range-Doppler map, the processor compares a value of the data point with a first threshold value.

9. The automotive radar system of claim 8 , wherein, if the value of the data point exceeds the first threshold, the processor compares values of a plurality of neighboring data points in the averaged range-Doppler map to a second threshold value.

10. The automotive radar system of claim 9 , wherein, if the values of the neighboring data points exceed the second threshold value, then the processor identifies the data point as a point in a blob.

11. The automotive radar system of claim 10 , wherein, if a quantity of neighboring data points identified as points in a blob exceeds a predetermined threshold, then the processor determines that the neighboring data points constitute a blob.

12. The automotive radar system of claim 1 , wherein the processor ceases analyzing data points in the averaged range-Doppler map if the radar system detects an object in the region that is unrelated to any blob detected in the averaged range-Doppler map.

13. A method of processing in an automotive radar system, the method comprising:

transmitting a plurality of radar signals into a region;

detecting reflected radar signals and converting the reflected radar signals into digital data signals;

generating from the digital data signals a plurality of range-Doppler maps for the region over time;

averaging the plurality of range-Doppler maps to generate an averaged range-Doppler map for the region;

analyzing data points in the averaged range-Doppler map to detect blobs in the averaged range Doppler map; and

if a blob is detected in the averaged range-Doppler map, indicating the radar detector to be unblocked.

14. The method of claim 13 , wherein, if a blob is not detected in the averaged range-Doppler map, the radar detector is indicated to be blocked.

15. The method of claim 13 , wherein a blob in the averaged range-Doppler map is considered to be due to radar returns from an extended object which is stationary with respect to a ground surface in an environment in which the automotive radar system is operating.

16. The method of claim 15 , wherein the extended object is a surface of a road on which the host vehicle is traveling.

17. The method of claim 15 , wherein the extended object is a curb along a side of a road on which the host vehicle is traveling.

18. The method of claim 13 , wherein the plurality of range-Doppler maps comprise 150 range-Doppler maps.

19. The method of claim 13 , wherein the radar signals have a frequency of approximately 77 GHz.

20. The method of claim 13 , wherein analyzing data points in the averaged range-Doppler map comprises, for each data point in the averaged range-Doppler map, comparing a value of the data point with a first threshold value.

21. The method of claim 20 , wherein analyzing data points in the averaged range-Doppler map comprises, if the value of the data point exceeds the first threshold, comparing values of a plurality of neighboring data points in the averaged range-Doppler map to a second threshold value.

22. The method of claim 21 , wherein analyzing data points in the averaged range-Doppler map comprises, if the values of the neighboring data points exceed the second threshold value, identifying the data point as a point in a blob.

23. The method of claim 22 , wherein analyzing data points in the averaged range-Doppler map comprises, if a quantity of neighboring data points identified as points in a blob exceeds a predetermined threshold, determining the neighboring data points to constitute a blob.

24. The method of claim 13 , wherein analyzing data points in the averaged range-Doppler map is stopped if an object that is unrelated to any blob detected in the averaged range-Doppler map is detected in the region.