Granted Patent B2

US 12,591,300 · App. 17/710,956 · Granted Mar 31, 2026

Inventors: Mathew Noel Rekow (Almeda, CA); David S. Hall (Oakland, CA); Sunil Kumar Singh Khatana (Sunnyvale, CA); Sharath Nair (San Jose, CA); John Kua (San Jose, CA)

Assignee: Velodyne Lidar USA, Inc.

G06F3/012G01S7/4813G01S7/4865G01S7/497G01S7/51G01S17/894G06T2207/10028

Abstract

Claims (73)

1 . A light detection and ranging (LiDAR) detection method comprising:

scanning, by a LiDAR system comprising a LiDAR device, a field-of-view during one or more time periods to generate return signal data representing reflections of emitted LiDAR signals from objects within the field-of-view;

scanning, by a digital camera mounted on a same gimbal as the LiDAR device such that the camera and the LiDAR device share a common optical axis and simultaneously scan a same field-of-view;

aggregating return signal data generated by the LiDAR device during the one or more time periods;

capturing digital image data of the field-of-view from the camera during the one or more time periods;

identifying one or more fiducial markers within the field-of-view based on the digital image data captured by the camera;

associating each identified fiducial marker in the digital image data with a corresponding region or feature in the aggregated return signal data from the LiDAR device based on a spatial correspondence provided by the shared optical axis and simultaneous scanning of the LiDAR device and the digital camera;

comparing each of the identified fiducial markers to a respective reference fiducial marker of a plurality of reference fiducial markers;

detecting, based on the comparison, miscalibration of an extrinsic parameter associated with a position and/or an orientation of the LiDAR device; and

initiating an action to remediate the detected miscalibration of the extrinsic parameter.

2 . The method of claim 1 , wherein scanning the field-of-view during the one or more time periods comprises:

emitting, by one or more transmitters, one or more optical signals; and

receiving, by one or more receivers, one or more return signals corresponding to the one or more optical signals, wherein each of the one or more LiDAR devices includes at least one of the one or more transmitters and at least one of the one or more receivers.

3 . The method of claim 1 , wherein the return signal data are derived from the one or more return signals and comprise a point cloud of measurements corresponding to the one or more optical signals.

4 . The method of claim 3 , wherein the return signal data comprise one or more measurements of range from the LiDAR system to one or more objects in an environment of the LiDAR system.

5 . The method of claim 1 , wherein the LiDAR system includes and/or accesses the plurality of reference fiducial markers and wherein the plurality of reference fiducial markers comprise data representing visual attributes of objects of standardized shapes and/or sizes.

6 . The method of claim 5 , wherein the objects of standardized shapes and/or sizes comprise field markings and/or fixtures.

7 . The method of claim 1 , wherein comparing each of the identified fiducial markers to the respective reference fiducial marker comprises:

for each of the identified fiducial markers, selecting the respective reference fiducial marker based on data representing visual attributes of the respective identified fiducial marker.

8 . A light detection and ranging (LiDAR) detection method comprising:

scanning, by a LiDAR system comprising one or more LiDAR devices, a field-of-view during one or more time periods;

aggregating return signal data obtained during the one or more time periods;

identifying one or more fiducial markers represented by the aggregated return signal data;

comparing each of the identified fiducial markers to a respective reference fiducial marker of a plurality of reference fiducial markers;

detecting, based on the comparison, miscalibration of an extrinsic parameter associated with a position and/or an orientation of at least one of the one or more LiDAR devices; and

initiating an action to remediate the detected miscalibration of the extrinsic parameter;

wherein comparing each of the identified fiducial markers to the respective reference fiducial marker comprises:

identifying a distortion based on a difference between data representing one or more visual attributes of the identified fiducial marker and data representing one or more visual attributes of the respective reference fiducial marker; and

comparing the distortion to a distortion threshold.

9 . The method of claim 8 , wherein initiating the action to remediate the detected miscalibration of the extrinsic parameter comprises:

generating an alert recommending recalibration of one or more extrinsic parameters of the LiDAR system.

10 . The method of claim 8 , wherein the distortion comprises a difference between a length, a width, and/or a height of the identified fiducial marker and the respective reference fiducial marker or a ratio between the length, the width, and/or the height of the identified fiducial marker and the respective reference fiducial marker.

11 . The method of claim 8 , wherein a type of the distortion corresponds to whether the distortion is a difference between a length, a width, and/or a height of the identified fiducial marker and the respective reference fiducial marker.

12 . The method of claim 8 , wherein the distortion comprises an average distortion for a subset of the one or more identified fiducial markers, wherein each identified fiducial marker in the subset of the one or more identified fiducial markers corresponds to a particular reference fiducial marker.

13 . A LiDAR system comprising:

a LiDAR device configured to scan a field-of-view during one or more time periods and to generate return signal data representing reflections of emitted LiDAR signals from objects within the field-of-view;

a digital camera mounted on a same gimbal as the LiDAR device such that the camera and the LiDAR device share a common optical axis and simultaneously scan a same field-of-view; and

a processing device configured to:

aggregate the return signal data generated by the LiDAR device during the one or more time periods;

capture digital image data of the field-of-view from the camera during the one or more time periods;

identify one or more fiducial markers within the field-of-view based on the digital image data captured by the camera;

associate each identified fiducial marker in the digital image data with a corresponding region or feature in the aggregated return signal data from the LiDAR device based on a spatial correspondence provided by the shared optical axis and simultaneous scanning of the LiDAR device and the digital camera;

compare each of the identified fiducial markers to a respective reference fiducial marker of a plurality of reference fiducial markers;

detect, based on the comparison, miscalibration of an extrinsic parameter associated with a position and/or an orientation of the LiDAR device; and

initiate an action to remediate the detected miscalibration of the extrinsic parameter.

14 . The system of claim 13 , wherein the one or more LiDAR devices are configured to scan a field-of-view during one or more time periods by:

emitting, by one or more transmitters, one or more optical signals; and

receiving, by one or more receivers, one or more return signals corresponding to the one or more optical signals, wherein each of the one or more LiDAR devices includes at least one of the one or more transmitters and at least one of the one or more receivers.

15 . The system of claim 13 , wherein the return signal data are derived from the one or more return signals and comprise a point cloud of measurements corresponding to the one or more optical signals.

16 . The system of claim 13 , wherein the processing device is configured to compare each of the identified fiducial markers to the respective reference fiducial marker of the plurality of reference fiducial markers by:

selecting, for each of the identified fiducial markers, the respective reference fiducial marker based on data representing visual attributes of the respective identified fiducial marker.

17 . A LiDAR system comprising:

one or more LiDAR devices configured to scan a field-of-view during one or more time periods; and

a processing device configured to:

aggregate return signal data obtained during the one or more time periods;

identify one or more fiducial markers represented by the aggregated return signal data;

compare each of the identified fiducial markers to a respective reference fiducial marker of a plurality of reference fiducial markers;

detect, based on the comparison, miscalibration of an extrinsic parameter associated with a position and/or an orientation of at least one of the one or more LiDAR devices; and

initiate an action to remediate the detected miscalibration of the extrinsic parameter;

wherein the processing device is configured to compare each of the identified fiducial markers to the respective reference fiducial marker of the plurality of reference fiducial markers by:

identifying a distortion based on a difference between data representing one or more visual attributes of the identified fiducial marker and data representing one or more visual attributes of the respective reference fiducial marker; and

comparing the distortion to a distortion threshold.

18 . The system of claim 17 , wherein the processing device is configured to initiate the action to remediate the detected miscalibration of the extrinsic parameter by:

generating an alert recommending recalibration of one or more extrinsic parameters of the LiDAR system.

19 . The system of claim 17 , wherein the distortion comprises a difference between a length, a width, and/or a height of the identified fiducial marker and the respective reference fiducial marker or a ratio between the length, the width, and/or the height of the identified fiducial marker and the respective reference fiducial marker.

20 . The system of claim 17 , wherein a type of the distortion corresponds to whether the distortion is a difference between a length, a width, and/or a height of the identified fiducial marker and the respective reference fiducial marker.

21 . The system of claim 17 , wherein the distortion comprises an average distortion for a subset of the one or more identified fiducial markers, wherein each identified fiducial marker in the subset of the one or more identified fiducial markers corresponds to a particular reference fiducial marker.

22 . The system of claim 13 , wherein the system comprises a plurality of LiDAR devices and a corresponding plurality of digital cameras disposed at fixed locations around an environment, each digital camera being mounted on a same gimbal with a corresponding LiDAR device such that the camera and the LiDAR device share a common optical axis and simultaneously scan a same field-of-view.

23 . The system of claim 22 , wherein the processing device is further configured to perform both temporal and spatial calibration across the plurality of LiDAR devices and cameras, including synchronizing data acquisition using a precision time protocol or generalized precision time protocol and aligning the positions and orientations of the devices relative to a reference coordinate system.

24 . The system of claim 22 , wherein the processing device is further configured to:

generate a three-dimensional point cloud of the environment from the return signal data aggregated from the plurality of LiDAR devices;

overlay color image data from the plurality of digital cameras onto the three-dimensional point cloud; and

generate a photorealistic or colorized three-dimensional point cloud or video of the environment based on the overlaid color image data and point cloud.

Assignments (6)

Continuity (3)

References Cited (15)