Automated vehicle radar system with self-calibration

1. A radar system comprising:

an antenna mounted on a host-vehicle, wherein the antenna is used to broadcast a radar-signal and detect a reflected-signal arising from a reflection of the radar-signal by an object;

a transceiver in communication with the antenna, wherein the transceiver determines a distance, an angle, and a range-rate of the object relative to the antenna based on the radar-signal and the reflected-signal; and

a controller in communication with the transceiver, wherein the controller is configured to

determine a speed of the host-vehicle;

determine that the object is stationary based on the speed, the angle, and the range-rate;

store in a memory a plurality of detections that correspond to multiple instances of the distance, the angle, and the range-rate as the host-vehicle travels by the object;

select an ideal-response of angle versus range-rate based on the speed;

determine, in response to a determination that the object is stationary, a calibration-matrix of the system for a plurality of angles of arrival to the antenna, said calibration-matrix based on a difference between the plurality of detections and the ideal-response; and

adjust an indicated-angle to a subsequent-object in accordance with the calibration-matrix.

2. The system in accordance with claim 1 , wherein the controller is configured to adjust an indicated-distance and an indicated-range-rate to the subsequent-object in accordance with the calibration-matrix.

3. The system in accordance with claim 1 , wherein the difference is based on an angle difference between an indicated-angle at an indicated-range-rate and an ideal-angle at an ideal-range-rate equal to the indicated-range-rate.

4. The system in accordance with claim 1 , wherein an instance of the plurality of detections associated with the object is used to determine the calibration-matrix when a face-linearity of the object is less than a linearity-threshold.

5. The system in accordance with claim 1 , wherein an instance of the plurality of detections associated with the object is used to determine the calibration-matrix when the distance is less than a distance-threshold.

6. The system in accordance with claim 1 , wherein the plurality of detections includes instances of the distance, the angle, and the range-rate from a plurality of objects.

7. The system in accordance with claim 1 , wherein the antenna includes a plurality of receive-elements, and each instance of the plurality of detections includes complex-voltages from each of the plurality of receive-elements.

8. The system in accordance with claim 7 , wherein the calibration-matrix is configured to transform the complex-voltages.

9. The system in accordance with claim 1 , wherein the calibration-matrix comprises distinct correction factors for each of the plurality of angles of arrival.

10. The system in accordance with claim 1 , wherein the plurality of angles of arrival in the calibration-matrix are defined by angle intervals between each of the plurality of angles of arrival.

11. A method comprising:

broadcasting a radar-signal;

detecting a reflection of the radar-signal by an object;

determining a distance, an angle, and a range-rate of the object relative to an antenna used to detect the reflected-signal;

determining a speed of a host-vehicle on which the antenna is mounted;

determining that the object is stationary based on the speed, the angle, and the range-rate;

storing in a memory a plurality of detections that correspond to multiple instances of the distance, the angle, and the range-rate as the host-vehicle travels by the object;

selecting an ideal-response of angle versus range-rate based on the speed;

determining, in response to determining that the object is stationary, a calibration-matrix for a plurality of angles of arrival to the antenna, said calibration-matrix based on a difference between the plurality of detections and the ideal-response; and

adjusting an indicated-angle to a subsequent-object in accordance with the calibration-matrix.

12. The method in accordance with claim 11 , wherein the method comprises

adjusting an indicated-distance and an indicated-range-rate to the subsequent-object in accordance with the calibration-matrix.

13. The method in accordance with claim 11 , wherein the difference is based on an angle difference between an indicated-angle at an indicated-range-rate and an ideal-angle at an ideal-range-rate equal to the indicated-range-rate.

14. The method in accordance with claim 11 , wherein an instance of the plurality of detections associated with the object is used to determine the calibration-matrix when a face-linearity of the object is less than a linearity-threshold.

15. The method in accordance with claim 11 , wherein an instance of the plurality of detections associated with the object is used to determine the calibration-matrix when the distance is less than a distance-threshold.

16. The method in accordance with claim 11 , wherein the plurality of detections includes instances of the distance, the angle, and the range-rate from a plurality of objects.

17. The method in accordance with claim 11 , wherein the antenna includes a plurality of receive-elements, and each instance of the plurality of detections includes complex-voltages from each of the plurality of receive-elements.

18. The system in accordance with claim 17 , wherein the calibration-matrix is configured to transform the complex-voltages.

19. The system in accordance with claim 11 , wherein the calibration-matrix comprises distinct correction factors for each of the plurality of angles of arrival.

20. The system in accordance with claim 11 , wherein the plurality of angles of arrival in the calibration-matrix are defined by angle intervals between each of the plurality of angles of arrival.