Sensor fusion for dynamic mapping
A local computing device receives lidar data and radar data from one or more road side units (RSUs). The local computing device performs ground plane removal based on range to detect targets and perform local sensor fusion. The local computing device may use a global nearest neighbor (GNN) algorithm and a Kalman filter. The local computing device may create an HD map or the data may be brought together with other target data at a central computing device to produce the HD map. Vehicle position and motion are controlled based on the HD map. Detecting and removing a ground plane based on range are illustrated. Fusion, ground plane removal, and delay filtering may be used in various contexts, such as roadways, parking lots and shipping yards.
1 . A method for producing a high definition map (HD map) for control of one or more autonomous vehicles, the one or more autonomous vehicles including a first vehicle, the method comprising:
receiving, at a local computing device, first lidar data and first radar data related to the first vehicle;
estimating, based on the first radar data, an initial range to the first vehicle;
performing a local sensor fusion at the local computing device, wherein the local sensor fusion includes removing, based on a clustering radius associated with the first vehicle, a ground plane associated with the first vehicle, and
determining, based on the local sensor fusion, the HD map, wherein the HD map indicates a position and a velocity of the first vehicle, a result of lidar detection of the first vehicle, and a result of radar detection of the first vehicle, wherein
the clustering radius is set longer as a distance from a first road side unit to the first vehicle increases by comparing the initial range with one or more range thresholds and setting the clustering radius based on the comparing.
2 . The method of claim 1 , further comprising controlling, based on the position and the velocity indicated by the HD map, the first vehicle to navigate in a parking lot to pick up or drop off a person.
3 . The method of claim 1 , further comprising controlling, based on the position and the velocity indicated by the HD map, the first vehicle to navigate in a shipping yard to pick up or drop off a shipment.
4 . The method of claim 1 , further comprising:
receiving, at the local computing device, second lidar data and second radar data related to the first vehicle,
wherein the performing the local sensor fusion further comprises:
applying a delay filter to compare timestamps of the first lidar data and the second lidar data,
discarding the second lidar data when the comparison of the timestamps indicates a difference in timestamps more than a threshold time, and
using, when the difference in timestamps is equal to or less than the threshold time, the second lidar data as an input of the local sensor fusion.
5 . The method of claim 1 , further comprising:
forming visual display data based on the HD map;
sending the visual display data to a display device; and
displaying the visual display data on the display device for monitoring, by a person, of the first vehicle.
6 . The method of claim 1 , further comprising:
determining a first control command for the first vehicle;
sending the first control command to a vehicle controller of the first vehicle at a first time;
adjusting, by the vehicle controller based on the first control command, a position or a velocity of the first vehicle;
determining a second control command for the first vehicle; and
sending the second control command to the vehicle controller of the first vehicle at a second time, wherein the first time and the second time correspond to a command rate of between 5 Hz and 20 Hz.
7 . The method of claim 1 , wherein the performing the local sensor fusion comprises:
estimating a point cloud by removing a ground plane portion from the first lidar data to obtain a second point cloud;
identifying an initial estimated position and initial estimated velocity, in first local coordinates, of the first vehicle by a clustering of the point cloud based on the clustering radius.
8 . The method of claim 7 , wherein the performing the local sensor fusion further comprises:
determining an updated position and updated estimated velocity, in the first local coordinates, by applying a first local Kalman filter to the initial estimated position, the initial estimated velocity and the initial range; and
converting the updated position and updated estimated velocity to global coordinates to obtain local data.
9 . The method of claim 8 , wherein the one or more range thresholds comprises a first range threshold, a second range threshold and a third range threshold, and wherein the performing the local sensor fusion further comprises:
estimating the point cloud by removing the ground plane portion by:
when the initial range is less than a first range threshold, estimating the ground plane portion based on:
the clustering radius, wherein the clustering radius is a first clustering radius, and
a first bounding volume,
when the initial range is not less than the first range threshold and is less than a second range threshold, estimating the ground plane portion based on:
the clustering radius, wherein the clustering radius is a second clustering radius, and
a second bounding volume,
when the initial range is not less than the second range threshold and is less than a third threshold, estimating the ground plane portion based on:
the clustering radius, wherein the clustering radius is a third clustering radius, and
a third bounding volume, and
when the initial range is greater than the third threshold, estimating the ground plane portion as non-existent; and
obtaining the local data, at least in part, by removing the ground plane portion from the point cloud.
10 . The method of claim 9 , wherein the first range threshold is 50 meters, dimensions of the first bounding volume in x-coordinates, y-coordinates and z-coordinates are 8, 50, and 6 meters, respectively, and the first clustering radius is 1.0 meter.
11 . The method of claim 9 , wherein the second range threshold is 120 meters, dimensions of the second bounding volume in x-coordinates, y-coordinates and z-coordinates are 8, 70, and 6 and meters, respectively, and the second clustering radius is 1.5 meters.
12 . The method of claim 9 , wherein a third range threshold is 200 meters, dimensions of the third bounding volume in x-coordinates, y-coordinates and z-coordinates are 8, 80, and 6 meters, respectively, and the third clustering radius is 2.0 meters.
13 . The method of claim 1 , wherein the receiving, at the local computing device, first lidar data and first radar data, comprises receiving the first lidar data and the first radar data from a first road side unit (RSU).
14 . The method of claim 13 , further comprising:
sending local data from the local computing device to a central computing device;
receiving, at a second local computing device from a second RSU, second lidar data and second radar data related to the first vehicle;
performing a second local sensor fusion at the second local computing device;
sending second local data based on global coordinates from the second local computing device to the central computing device;
receiving at the central computing device the local data and the second local data; and
determining, based on a global fusion at the central computing device of the local data and the second local data, the HD map, wherein the HD map indicates a position and velocity, in global coordinates, of the first vehicle.
15 . The method of claim 14 , wherein the local computing device, the second local computing device and the central computing device are geographically distributed.
16 . The method of claim 14 , wherein the local computing device, the second local computing device and the central computing device are geographically co-located.
17 . The method of claim 1 , further comprising:
identifying, by the local computing device, an estimated position and estimated velocity, in first local coordinates, of the first vehicle by a clustering of a point cloud based on a clustering radius;
converting the estimated position and the estimated velocity to global coordinates; and
sending the position in global coordinates and the velocity in global coordinates to a central computing device,
wherein the central computing device is located within the first vehicle.
18 . The method of claim 17 , further comprising transmitting the HD map from the first vehicle to a second vehicle, wherein the one or more autonomous vehicle comprises the second vehicle.
19 . A local computing device comprising:
a communication interface; and
at least one processor configured to:
receive, via the communication interface, first lidar data and first radar data related to a first vehicle of one or more autonomous vehicles;
estimate, based on the first radar data, an initial range to the first vehicle;
perform a local sensor fusion at the local computing device, wherein the local sensor fusion includes removing a ground plane associated with the first vehicle based on a clustering radius associated with the first vehicle, and
determine, based on the local sensor fusion, a high definition (HD) map, wherein the HD map indicates a position and velocity of the first vehicle, a result of lidar detection of the first vehicle, and a result of radar detection of the first vehicle, wherein
the clustering radius is set longer as a distance from a first road side unit to the first vehicle increases by comparing the initial range with one or more range thresholds and setting the clustering radius based on the comparing.
20 . A non-transitory computer readable medium comprising instructions for execution by a processor in a local computing device for causing the local computing device to:
receive, via a communication interface, first lidar data and first radar data related to a first vehicle of one or more autonomous vehicles;
estimate, based on the first radar data, an initial range to the first vehicle;
perform a local sensor fusion at the local computing device, wherein the local sensor fusion includes removing a ground plane associated with the first vehicle based on a clustering radius associated with the first vehicle, and
determine, based on the local sensor fusion, a high definition (HD) map, wherein the HD map indicates a position and velocity of the first vehicle, a result of lidar detection of the first vehicle, and a result of radar detection of the first vehicle, wherein
the clustering radius is set longer as a distance from a first road side unit to the first vehicle increases by comparing the initial range with one or more range thresholds and setting the clustering radius based on the comparing.