Vehicle Sensor Synchronization Using an External Clock Source

• US 20190011544A1
• Filed: 07/07/2017
• Published: 01/10/2019
• Est. Priority Date: 07/07/2017
• Status: Active Grant

• Current Assignee: Waymo LLC (Alphabet Inc.)
• Original Assignee: Waymo LLC (Alphabet Inc.)
• Inventors: Gassend, Blaise, Ingram, Benjamin, Wachter, Luke
• Granted Patent: US 10,866,313 B2
• Time in Patent Office: Days
• CPC Class Codes: G01S 13/931 of land vehicles
• CPC Class Codes: G01S 17/86 Combinations of lidar systems with systems other than lidar, radar or sonar, e.g. with direction finders
• CPC Class Codes: G01S 17/87 Combinations of systems using electromagnetic waves other than radio waves
• CPC Class Codes: G01S 17/931 of land vehicles
• CPC Class Codes: G01S 2013/93271 in the front of the vehicles
• CPC Class Codes: G01S 2013/93272 in the back of the vehicles
• CPC Class Codes: G01S 2013/93273 on the top of the vehicles
• CPC Class Codes: G01S 7/4039 of sensor or antenna obstruction, e.g. dirt- or ice-coating
• CPC Class Codes: G01S 7/4813 Housing arrangements
• CPC Class Codes: G01S 7/4972 Alignment of sensor

Abstract

An example system includes a light detection and ranging (LIDAR) device that scans a field-of-view defined by a pointing direction of the LIDAR device. The system also includes an actuator that adjusts the pointing direction of the LIDAR device. The system also includes a communication interface that receives timing information from an external system. The system also includes a controller that causes the actuator to adjust the pointing direction of the LIDAR device based on at least the received timing information.

Claims

1. A system comprising:

a light detection and ranging (LIDAR) device that scans a field-of-view defined by a pointing direction of the LIDAR device;

an actuator that adjusts the pointing direction of the LIDAR device;

a communication interface that receives timing information from an external system; and

a controller that causes the actuator to adjust the pointing direction of the LIDAR device based on at least the received timing information.

2. The system of claim 1, further comprising:

one or more sensors that provide an indication of an orientation of a vehicle relative to an environment of the vehicle, wherein the LIDAR device mounts to the vehicle, and wherein the controller causes the actuator to adjust the pointing direction of the LIDAR device further based on data from the one or more sensors.

3. The system of claim 2, wherein the one or more sensors comprise a yaw sensor that indicates a measurement of a yaw direction of the vehicle in the environment.

4. The system of claim 2, wherein the one or more sensors comprise a yaw_rate sensor that indicates a measurement of a yaw_rate of change to a yaw direction of the vehicle in the environment.

5. The system of claim 1, further comprising:

one or more devices that provide an indication of an orientation of the LIDAR device relative to a vehicle, wherein the LIDAR device mounts to the vehicle, and wherein the controller causes the actuator to adjust the pointing direction of the LIDAR device further based on data from the one or more devices.

6. The system of claim 5, wherein the one or more devices include a LIDAR direction indicator that indicates a measurement of the pointing direction of the LIDAR device relative to the vehicle.

7. The system of claim 5, wherein the one or more devices include a LIDAR rotation indicator that indicates a measurement of a rate of change to the pointing direction of the LIDAR device relative to the vehicle.

8. The system of claim 1, further comprising a satellite navigation system sensor associated with the communication interface, wherein the timing information relates to a reference clock signal indicated by data from the satellite navigation system sensor.

9. The system of claim 1, wherein the timing information relates to a reference clock signal indicated by data from one or more network servers accessible to the system via the communication interface.

10. The system of claim 1, wherein the timing information relates to a reference clock signal indicated by data from a cellular communication network accessible to the system via the communication interface.

11. A vehicle comprising:

a light detection and ranging (LIDAR) device that scans a field-of-view defined by a pointing direction of the LIDAR device;

an actuator that rotates the LIDAR device about an axis to adjust the pointing direction of the LIDAR device;

a communication interface that receives timing information from an external system; and

a controller that causes the actuator to adjust one or more characteristics of the rotation of the LIDAR device based on at least the received timing information.

12. The vehicle of claim 11, wherein the one or more characteristics include a direction of the rotation of the LIDAR device about the axis.

13. The vehicle of claim 11, wherein the one or more characteristics include a phase of the rotation of the LIDAR device about the axis.

14. The vehicle of claim 13, further comprising:

a sensor that provides an indication of a yaw direction of the vehicle in an environment of the vehicle, wherein the controller causes the actuator to adjust the phase of the rotation further based on the yaw direction indicated by the yaw sensor.

15. The vehicle of claim 13, further comprising:

a device that indicates a measured position of the LIDAR device about the axis, wherein the controller causes the actuator to adjust the phase of the rotation further based on the measured position.

16. The vehicle of claim 11, wherein the one or more characteristics include a frequency of the rotation of the LIDAR device about the axis.

17. The vehicle of claim 16, further comprising:

a sensor that provides an indication of a yaw_rate of change to a yaw direction of the vehicle in the environment, wherein the controller adjusts the frequency of the rotation of the LIDAR device about the axis further based on the yaw_rate.

18. The vehicle of claim 16, further comprising:

a device that indicates a measurement of the frequency of the rotation of the LIDAR device about the axis, wherein the controller adjusts the frequency of the rotation of the LIDAR device further based on the measurement of the frequency.

19. A method comprising:

scanning, via a light detection and ranging (LIDAR) device, a field-of-view defined by a pointing direction of the LIDAR device;

receiving, via a communication interface, timing information from an external system; and

adjusting, via an actuator, the pointing direction of the LIDAR device based on at least the received timing information.

20. The method of claim 19, further comprising:

determining a target pointing direction of the LIDAR device based on the received timing information;

determining a current pointing direction of the LIDAR device based on measurements indicated by one or more sensors; and

modulating power provided to the actuator based on a difference between the target pointing direction and the current pointing direction.