Object tracking system with radar/vision fusion for automated vehicles

1. An object tracking system suitable for use on an automated vehicle, said system comprising:

a camera used to capture an image of a vision-field-of-view (VFOV) of the camera;

a radar-sensor used to detect a radar-signal reflected from a radar-field-of-view (RFOV) that overlaps the VFOV; and

a controller in communication with the camera and the radar-sensor, said controller configured to assign a vision-identification to each vision-track that indicates a vision-motion-status associated with an instance of an object detected in the image by the controller,

assign a radar-identification to each radar-glob that indicates a radar-motion-status associated with an instance of grouped-tracklets indicated by the radar-signal,

determine a match-feasibility for each combination of vision-track and radar-glob, wherein each match-feasibility is a binary-value set equal to one (1) when at least one of

a) an azimuth-difference between a vision-angle of the vision-track and a radar-angle of a radar-glob is less than an azimuth-threshold,

b) a distance-difference between a vision-distance of the vision-track and a radar-distance of a radar-glob is less than a distance-threshold, and

c) a speed-difference between a vision-speed of the vision-track and a radar-speed of a radar-glob is less than a speed-threshold,

select from all possible vision-track and radar-glob pairing-combinations a list of feasible-match-patterns and determine a fused track based on the vision-motion-status and the radar-motion-status, wherein a pairing-combination is a feasible-match-pattern when the match-feasibility of each combination of vision-track and radar-glob in the pairing-combination is equal to one,

determine a normalized-value for each instance of the feasible-match-pattern, and

calculate a raw-probability for each combination of vision-track and radar-glob by summing the normalized-values of the feasible-match-patterns that indicate a match for that combination of vision-track and radar-glob.

2. The system in accordance with claim 1 , wherein the controller is configured to

determine a match-probability for each combination of vision-track and radar-glob by low-pass filtering of the raw-probability obtained for that combination,

determine a need for a re-organize test of the existing associations between vision-tracks and radar-globs by comparing the match-probabilities for combinations of vision-track and radar-glob to a threshold, and

implement a re-organize test of associations between vision-tracks and radar-globs when one of the match-probabilities transitions the threshold.

3. The system in accordance with claim 1 , wherein the match-feasibility for a combination of vision-track and radar-glob is set equal to zero (0) when the azimuth-difference is greater than the azimuth-threshold.

4. The system in accordance with claim 1 , wherein each match-feasibility is set equal to one (1) only when

a) the azimuth-difference is less than the azimuth-threshold,

b) the distance-difference is less than the distance-threshold, and

c) the speed-difference between is less than the speed-threshold.

5. The system in accordance with claim 1 , wherein each match-feasibility is set equal to one (1) when at least one of

a) the azimuth-difference is less than the azimuth-threshold,

b) the distance-difference is less than the distance-threshold,

c) the speed-difference between is less than the speed-threshold, and

d) a vision-motion-status of the vision-track matches a radar-motion-status of the radar glob, wherein the vision-motion-status and the radar-motion-status are each characterized by one of oncoming, stationary, and receding.

6. The system in accordance with claim 1 , wherein the vision-speed and the radar-speed are indicative of a longitudinal-velocity of the vision-track and the radar-glob, respectively.

7. The system in accordance with claim 1 , wherein the vision-distance and the radar-distance are indicative of a longitudinal-position of the vision-track and the radar-glob, respectively.

8. The system in accordance with claim 1 , wherein the quality-value is based on a reciprocal of a square-root of a weighted-summation of squares of the azimuth-difference, the distance-difference, and the speed-difference.

9. The system in accordance with claim 1 , wherein the controller is configured to perform an occlusion-test on radar-globs characterized by substantially equal values of azimuth-angle to null the match-probability for any combination of vision-track and radar-glob that the occlusion-test indicates is not possible.