Estimating target heading using a single snapshot

1. A computer implemented method performed by one or more processors, comprising:

obtaining a snapshot of radar data comprising Doppler velocities and spatial positions of a plurality of detection points of a target, the target comprising a vehicle;

conducting a first estimation of a heading of the target based on the spatial positions;

conducting a second estimation of the heading of the target based on the Doppler velocities;

obtaining a combined estimation of the heading of the target based on a weighted sum of the first estimation and the second estimation; and

inferring an intention of the target based on a comparison of the combined estimation with an orientation of a lane in which the target is situated, wherein the inferred intention of the target comprises estimated or predicted trajectories of the target.

2. The computer implemented method of claim 1 , further comprising determining a first weight associated with the first estimation of the weighted sum and a second weight associated with the second estimation of the weighted sum based on respective first and second weights, obtained from a previous cycle, at a location within a threshold distance of at least a portion of the spatial positions.

3. The computer implemented method of claim 1 , wherein the conducting the second estimation is further based on a least-squares solution of a velocity vector of the target.

4. The computer implemented method of claim 1 , wherein the conducting the second estimation is further based on directions from each of the detection points to a radar sensor used to obtain the snapshot and magnitudes of Doppler speeds at each of the detection points.

5. The computer implemented method of claim 1 , further comprising:

determining, based on the first estimation, a bounding region enclosing the detection points, the bounding region indicating an orientation and a dimension of the target.

6. The computer implemented method of claim 5 , wherein the conducting the first estimation of the heading comprises determining a rectangular bounding region that minimizes a sum of distances from each detection point to a boundary of the rectangular bounding region.

7. The computer implemented method of claim 6 , wherein the distances are determined from each detection point to a nearest boundary of the determined rectangular bounding region.

8. The computer implemented method of claim 5 , further comprising determining a first weight associated with the first estimation of the weighted sum and a second weight associated with the second estimation of the weighted sum based on a variance of the combined estimation.

9. The computer implemented method of claim 5 , wherein the snapshot comprising the radar data is obtained from multiple radar sensors; and

the determining the boundary region is based on the radar data obtained from the multiple radar sensors.

10. The computer implemented method of claim 5 , further comprising:

obtaining a second snapshot of Lidar data comprising a plurality of second detection points within second threshold distances of at least a portion of the detection points;

determining, based on the second snapshot, a second bounding region enclosing the second detection points;

determining whether boundaries of the second bounding region are within third threshold distances of boundaries of the bounding region; and

in response to determining that the boundaries of the second bounding region are within third threshold distances of the boundaries of the bounding region, fusing the bounding region and the second bounding region.

11. The computer implemented method of claim 5 , further comprising:

obtaining a third snapshot of camera data comprising a plurality of third detection points within third threshold distances of at least a portion of the detection points;

determining, based on the third snapshot, a third bounding region enclosing the third detection points;

determining whether boundaries of the third bounding region are within fourth threshold distances of boundaries of the bounding region; and

in response to determining that the boundaries of the third bounding region are within fourth threshold distances of the boundaries of the bounding region, fusing the bounding region and the third bounding region.

12. The computer implemented method of claim 5 , wherein each of the detection points contacts a boundary of the bounding region or is located in an interior of the bounding region.

13. A system configured to determine a heading of a target, comprising:

a radar sensor configured to obtain at least a portion of a snapshot of radar data comprising Doppler velocities and spatial positions of a plurality of detection points of a target, the target comprising a vehicle;

one or more processors; and

a memory storing instructions that, when executed by the one or more processors, causes the system to perform:

conducting a first estimation of a heading of the target based on the spatial positions;

conducting a second estimation of the heading of the target based on the Doppler velocities;

obtaining a combined estimation of the heading of the target based on a weighted sum of the first estimation and the second estimation; and

inferring an intention of the target based on a comparison of the combined estimation with an orientation of a lane in which the target is situated, wherein the inferred intention of the target comprises estimated or predicted trajectories of the target.

14. The system of claim 13 , wherein the instructions further cause the system to perform:

determining a first weight associated with the first estimation of the weighted sum and a second weight associated with the second estimation of the weighted sum based on respective first and second weights, obtained from a previous cycle, at a location within a threshold distance of at least a portion of the spatial positions.

15. The system of claim 13 , wherein the conducting the second estimation is further based on a least-squares solution of a velocity vector of the target.

16. The system of claim 13 , wherein the instructions further cause the system to perform:

determining, based on the first estimation, a bounding region enclosing the detection points, the bounding region indicating an orientation and a dimension of the target.

17. The system of claim 16 , further comprising a second radar sensor configured to obtain a second portion of the snapshot comprising the radar data; and

the determining the boundary region is based on the portion and the second portion of the snapshot.

18. The system of claim 16 , wherein the conducting the first estimation of the heading comprises determining a rectangular bounding region that minimizes a sum of distances from each detection point to a boundary of the rectangular bounding region.

19. The system of claim 18 , wherein each of the detection points contacts a boundary of the rectangular bounding region or is located in an interior of the rectangular bounding region.