System for acquiring time-synchronized sensor data

• US 9,537,956 B1
• Filed: 12/11/2015
• Issued: 01/03/2017
• Est. Priority Date: 12/11/2015
• Status: Active Grant

• Current Assignee: Aurora Operations Incorporated (Aurora Innovation, Inc.)
• Original Assignee: Uber Technologies, Inc.
• Inventors: Sibenac, Mark, Strother, Daniel, Tascione, Daniel, Jones, Morgan, Brindza, Jordan
• Primary Examiner(s): Sample, Jonathan L
• Application Number:
  US14/967,154
• Time in Patent Office: 389 Days
• US Class Current: 1/1
• CPC Class Codes: H04L 67/125 involving control of end-device applications over a network
• CPC Class Codes: H04L 7/0331 with a digital phase-locked loop [PLL] processing binary samples, e.g. add/subtract logic for correction of receiver clock H04L7/0337 takes precedence
• CPC Class Codes: H04W 4/02 Services making use of location information
• CPC Class Codes: H04W 56/001 Synchronization between nodes
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks

Abstract

A sensor synchronization system for a sensor apparatus. The system synchronizes a local clock signal with an external timing signal. For example, the external timing signal may correspond to a pulse per second (PPS) signal received from a global positioning system (GPS) receiver. The system further generates a plurality of sensor pulses that are each offset in phase relative to the local clock signal by a respective amount. The system then activates a plurality of sensors of the sensor apparatus based at least in part on the plurality of sensor pulses.

Claims

1. A method of operating a sensor apparatus, the method comprising:

synchronizing a local clock signal with an external timing signal;

dividing a clock cycle of the local clock signal into a plurality of timing intervals;

generating a plurality of sensor pulses based at least in part on framerates or resolutions of each of a plurality of sensors of the sensor apparatus, wherein each of the plurality of sensor pulses are aligned with a respective one of the timing intervals; and

activating the plurality of sensors of the sensor apparatus based at least in part on the plurality of sensor pulses.

2. The method of claim 1, wherein activating the plurality of sensors includes:

determining a sensor activation schedule for activating each of the plurality of sensors such that each sensor activation coincides with one of the plurality of sensor pulses.

3. The method of claim 2, wherein activating the plurality of sensors includes:

transmitting at least one of the plurality of sensor pulses to each of the plurality of sensors, in accordance with the sensor activation schedule, to activate the respective sensors.

4. The method of claim 1, further comprising:

receiving the external timing signal from a global positioning system (GPS) receiver.

5. The method of claim 4, wherein the external timing signal is a pulse per second (PPS) signal.

6. The method of claim 1, wherein the number of timing intervals is based at least in part on the framerates or resolutions of the plurality of sensors.

7. The method of claim 1, wherein the plurality of sensors includes at least one of a camera or a laser rangefinder.

8. The method of claim 1, wherein the sensor apparatus corresponds to a machine vision camera for an autonomous vehicle.

9. The method of claim 8, further comprising:

generating a three-dimensional sensor image for navigating the autonomous vehicle based at least in part on the sensor data.

10. A sensor synchronization system, comprising:

clock synchronization circuitry to synchronize a local clock signal with an external timing signal;

a memory that stores instructions for operating a sensor apparatus; and

one or more processors that, upon executing the instructions, cause the sensor synchronization system to;

divide a clock cycle of the local clock signal into a plurality of timing intervals;

generate a plurality of sensor pulses based at least in part on framerates or resolutions of each of a plurality of sensors of the sensor apparatus, wherein each of the plurality of sensor pulses are aligned with a respective one of the timing intervals; and

activate the plurality of sensors of the sensor apparatus based at least in part on the plurality of sensor pulses.

11. The sensor synchronization system of claim 10, wherein the clock synchronization circuitry comprises a phase-locked loop (PLL).

12. The sensor synchronization system of claim 10, including further instructions to:

determine a sensor activation schedule for activating each of the plurality of sensors such that each sensor activation coincides with one of the plurality of sensor pulses.

13. The sensor synchronization system of claim 12, wherein execution of the instructions to activate the plurality of sensors causes the system to:

transmit at least one of the plurality of sensor pulses to each of the plurality of sensors, in accordance with the sensor activation schedule, to activate the respective sensors.

14. The sensor synchronization system of claim 10, wherein the clock synchronization circuitry receives the external timing signal from a global positioning system (GPS) receiver.

15. The sensor synchronization system of claim 14, wherein the external timing signal is a pulse per second (PPS) signal.

16. The sensor synchronization system of claim 10, wherein the number of timing intervals is based at least in part on the framerates or resolutions of the plurality of sensors.

17. The sensor synchronization system of claim 10, wherein the sensor apparatus corresponds to a machine vision camera for an autonomous vehicle, and wherein execution of the instructions further causes the system to:

generate a three-dimensional sensor image for navigating the autonomous vehicle based at least in part on the sensor data.

18. A non-transitory computer-readable storage medium containing instructions that, when executed by a processor of a sensor synchronization system, causes the sensor synchronization system to:

synchronize a local clock signal with an external timing signal;

divide a clock cycle of the local clock signal into a plurality of timing intervals;

generate a plurality of sensor pulses based at least in part on framerates or resolutions of each of a plurality of sensors, wherein each of the plurality of sensor pulses are aligned with a respective one of the timing intervals; and

activate the plurality of sensors based at least in part on the plurality of sensor pulses.