Patent ID: 11915440
Assignee: VELODYNE LIDAR USA, INC.
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 18:
19. A method of generating structured map data, the method comprising:
receiving time-stamped sensor data from at least one sensor disposed on a vehicle;
receiving video data comprising a plurality of video streams provided by a respective plurality of cameras disposed on the vehicle;
determining, based on the time-stamped sensor data, a plurality of spatial values each comprising a position of the vehicle and an associated time stamp, the plurality of spatial values including a particular spatial value indicating a particular position of the vehicle and a particular associated time stamp;
producing a point cloud comprising a plurality of relative positions of a fixed feature based on a first plurality of image records comprising a respective plurality of images depicting the fixed feature, the respective plurality of images being captured in the received video data;
producing a plurality of adjustments by determining an adjustment to the position of the vehicle for each spatial value of the plurality of spatial values, the plurality of adjustments based on a plurality of relative feature positions of a plurality of fixed features identified in the image records;
applying the plurality of adjustments to the position of the vehicle for each spatial value of the plurality of spatial values to produce a plurality of adjusted spatial values;
detecting a later position of the vehicle for the plurality of adjusted spatial values within a maximum loop closure distance of a prior position of the vehicle for the plurality of adjusted spatial values, the later position and prior position of the vehicle separated by one of a smallest loop time and a smallest loop distance; and
calculating a loop closure error from the time-stamped sensor data based on the later position, a first time stamp associated with the later position, a second time stamp associated with the prior position, and a third time stamp of the prior position.