Hardware centralized time synchronization hub for an autonomous driving vehicle

Patent metadata

Field	Value
Publication number	US-10788841-B2
Application number	US-201816112235-A
Country	US
Kind code	B2
Filing date	Aug 24, 2018
Priority date	Aug 24, 2018
Publication date	Sep 29, 2020
Grant date	Sep 29, 2020

Abstract

In one embodiment, a sensor unit to be utilized in an autonomous driving vehicle (ADV) includes a sensor interface coupled to a number of sensors mounted on a number of locations of an autonomous driving vehicle (ADV). The sensor unit includes a host interface to be coupled to a host system, where the host system is configured to perceive a driving environment surrounding the ADV based on sensor data obtained from the sensors and to plan a path to autonomously drive the ADV. The sensor unit includes a time synchronization hub device coupled to the sensor interface. The time synchronization hub device includes one or more TX and/or RX timestamp generators coupled to a time source, where the TX/RX timestamp generators generate TX/RX timestamps based on a time obtained from the time source to provide the TX/RX timestamps to one or more of the sensors.

First claim

What is claimed is:

1. A sensor unit utilized in an autonomous driving vehicle, the sensor unit comprising:
a sensor interface to be coupled to a plurality of sensors mounted on a plurality of locations of an autonomous driving vehicle (ADV);
a host interface to be coupled to a host system located at the ADV, wherein the host system is configured to perceive a driving environment surrounding the ADV based on sensor data obtained from the sensors and to plan a path to autonomously drive the ADV; and
a time synchronization hub device coupled to the sensor interface, wherein the time synchronization hub device comprises
one or more transmit (TX) timestamp generators coupled to a time source, wherein the TX timestamp generators generate TX timestamps based on a time obtained from the time source to provide the TX timestamps to one or more of the sensors indicating a time the sensors transmit sensor data to the host system located at the ADV via the host interface, and
one or more receive (RX) timestamp generators coupled to the time source, wherein the RX timestamp generators generate RX timestamps based on the time obtained from the time source to provide the RX timestamps to the same one or more of the sensors indicating a time when sensor data is received from the sensors such that each of the one or more of the sensors is associated with at least a TX timestamp and a RX timestamp.

2. The sensor unit of claim 1 , wherein a first of the sensors is coupled to a first of the TX timestamp generators and a first of the RX timestamp generators, wherein the first sensor is to receive a TX timestamp from the first TX timestamp generator and transmits sensor data and metadata including the TX timestamp to the sensor unit, wherein the first RX timestamp generator is to generate a RX timestamp to append to the metadata to indicate a time when the sensor data is received by the sensor interface.

3. The sensor unit of claim 1 , wherein a second of the sensors is coupled to a second of the RX timestamp generators without being coupled to a TX timestamp generator, wherein the second sensor is to transmit sensor data to the sensor unit without any transmit timestamp information, and wherein the second RX timestamp generator is to generate a RX timestamp to append to metadata of the sensor data to indicate a time when the sensor data is received by the sensor interface.

4. The sensor unit of claim 1 , wherein a third of the sensors is coupled to a third of the TX timestamp generators and the host system without being coupled to a RX timestamp generator, wherein the third sensor is to receive a TX timestamp from the third TX timestamp generator and the third sensor transmits sensor data and metadata directly to the host system, wherein the metadata includes TX timestamp information indicating a time when the sensor data is transmitted to the host system.

5. The sensor unit of claim 1 , wherein the synchronization hub device is coupled to the host system to synchronize a time of the host system.

6. The sensor unit of claim 5 , wherein the synchronization hub device is coupled to the host system via a peripheral component interconnect express bus.

7. The sensor unit of claim 1 , wherein a metadata for a camera sensor coupled to a TX timestamp generator includes camera trigger timestamp information.

8. The sensor unit of claim 1 , where a timestamp format of a TX timestamp or RX timestamp includes a ms:us:ns:mm:ss:hh:month:day:year format.

9. The sensor unit of claim 8 , further comprising a format converter unit coupled to a processor to cause the processor to convert a timestamp from one format to another.

10. The sensor unit of claim 1 , where a timestamp format of a TX timestamp or RX timestamp includes a mm:ss:hh:month:day:year format.

11. An autonomous driving system, comprising:
a plurality of sensors mounted on a plurality of locations of an autonomous driving vehicle (ADV);
a host system located at the ADV to perceive a driving environment surrounding the ADV based on sensor data obtained from the sensors and to plan a path to autonomously drive the ADV; and
a sensor unit coupled to the plurality of sensors and the host system, wherein the sensor unit comprises
a sensor interface to be coupled to the plurality of sensors mounted on the ADV,
a host interface to be coupled to the host system, and
a time synchronization hub device coupled to the sensor interface, wherein the time synchronization hub device includes
one or more transmit (TX) timestamp generators coupled to a time source, wherein the TX timestamp generators generate TX timestamps based on a time obtained from the time source to provide the TX timestamps to one or more of the sensors indicating a time the sensors transmit sensor data to the host system located at the ADV via the host interface, and
one or more receive (RX) timestamp generators coupled to the time source, wherein the RX timestamp generators generate RX timestamps based on the time obtained from the time source to provide the RX timestamps to the same one or more of the sensors indicating a time when sensor data is received from the sensors such that each of the one or more of the sensors is associated with at least a TX timestamp and a RX timestamp.

12. The system of claim 11 , wherein a first of the sensors is coupled to a first of the TX timestamp generators and a first of the RX timestamp generators, wherein the first sensor is to receive a TX timestamp from the first TX timestamp generator and transmits sensor data and metadata including the TX timestamp to the sensor unit, wherein the first RX timestamp generator is to generate a RX timestamp to append to the metadata to indicate a time when the sensor data is received by the sensor interface.

13. The system of claim 11 , wherein a second of the sensors is coupled to a second of the RX timestamp generators without being coupled to a TX timestamp generator, wherein the second sensor is to transmit sensor data to the sensor unit without any transmit timestamp information, and wherein the second RX timestamp generator is to generate a RX timestamp to append to metadata of the sensor data to indicate a time when the sensor data is received by the sensor interface.

14. The system of claim 11 , wherein a third of the sensors is coupled to a third of the TX timestamp generators and the host system without being coupled to a RX timestamp generator, wherein the third sensor is to receive a TX timestamp from the third TX timestamp generator and the third sensor transmits sensor data and metadata directly to the host system, wherein the metadata includes TX timestamp information indicating a time when the sensor data is transmitted to the host system.

15. The system of claim 11 , wherein the synchronization hub device is coupled to the host system to synchronize a time of the host system.

16. The system of claim 15 , wherein the synchronization hub device is coupled to the host system via a peripheral component interconnect express bus.

17. The system of claim 11 , wherein a metadata for a camera sensor coupled to a TX timestamp generator includes camera trigger timestamp information.

18. The system of claim 11 , where a timestamp format of a TX timestamp or RX timestamp includes a ms:us:ns:mm:ss:hh:month:day:year format.

19. The system of claim 18 , wherein the sensor unit further comprises a format converter unit coupled to a processor to cause the processor to convert a timestamp from one format to another.

20. The system of claim 11 , where a timestamp

Assignees

• Baidu Usa Llc

Inventors

• Zhang Manjiang
• Zhou Xu
• Kwan Oh
• Li Ji

Classifications

• B60R16/0231

  Circuits relating to the driving or the functioning of the vehicle (monitoring tyres B60C23/00; indicating overspeed B60K31/00; for dash boards B60K37/00, B60Q3/10; for indicating emergencies B60Q1/52; brake control systems B60T; registering or indicating the working of vehicles G07C5/00; measuring distance G01C, e.g. combinations of speed and distance G01C23/00; engine indicators G01L; measuring speed or acceleration G01P) · CPC title

• G06F1/12

  Synchronisation of different clock signals {provided by a plurality of clock generators} · CPC title

• G04R20/28

  Tuning or receiving; Circuits therefor · CPC title

• G04R20/26

  the radio signal being a near-field communication signal · CPC title

• G06F1/14

  Time supervision arrangements, e.g. real time clock · CPC title