Time synchronization for sensor data recording devices

Patent metadata

Field	Value
Publication number	US-11425673-B2
Application number	US-202017025807-A
Country	US
Kind code	B2
Filing date	Sep 18, 2020
Priority date	Jun 7, 2018
Publication date	Aug 23, 2022
Grant date	Aug 23, 2022

Abstract

A leader system for time synchronizing includes an interface and a processor. The interface is configured to receive a time standard. The processor is configured to determine whether a time jump is necessary in response to the time standard; and in response to determining that the time jump is necessary: 1) cause overwriting a sensor data buffer; 2) provide an indication to unregister one or more follower devices from a leader device; and 3) time jump a leader device time in response to the time standard.

First claim

What is claimed is:

1. A system, comprising:
an interface configured to receive a time standard; and
a processor configured to:
cause pausing of a collection of sensor data before a time jump;
determine whether the time jump is necessary, comprising to:
determine a time difference between the time standard and a leader device time; and
in response to a determination that the time difference is equal to or greater than a threshold value, determine that the time jump is necessary; and

in response to determining that the time jump is necessary:
cause overwriting a sensor data buffer;
provide an indication to unregister one or more follower devices from a leader device;
time jump the leader device time in response to the time standard; and
cause restarting the collection of the sensor data after the time jump.

2. The system of claim 1 , wherein the indication to unregister the one or more follower devices from the leader device comprises closing a network socket to which the one or more follower devices are connected.

3. A system, comprising:
an interface configured to receive a time standard; and
a processor configured to:
determine whether a time jump is necessary, comprising to:
determine a time difference between the time standard and a leader device time; and
in response to a determination that the time difference is equal to or greater than a threshold value, determine that the time jump is necessary;

in response to determining that the time jump is necessary:
cause overwriting a sensor data buffer;
provide an indication to unregister one or more follower devices from a leader device; and
time jump the leader device time in response to the time standard;

receive a registration request from the one or more follower devices; and
send a registration acknowledgement message in response to the registration request from the one or more follower devices, wherein the registration acknowledgement message includes a current leader device time.

4. A system, comprising:
an interface configured to receive a time standard; and
a processor configured to:
determine whether a time jump is necessary, comprising to:
determine a time difference between the time standard and a leader device time; and
in response to a determination that the time difference is equal to or greater than a threshold value, determine that the time jump is necessary;

in response to determining that the time jump is necessary:
cause overwriting a sensor data buffer;
provide an indication to unregister one or more follower devices from a leader device; and
time jump the leader device time in response to the time standard;

receive a registration request from the one or more follower devices;
determine whether a follower device of the one or more follower devices from which the registration request is received is on a white list; and
in response to determining that the follower device from which the registration request is received is on the white list, send a registration acknowledgement message to the follower device determined to be on the white list, wherein the registration acknowledgement message includes a current leader device time.

5. A method, comprising:
receiving a time standard;
causing pausing of a collection of sensor data before a time jump;
determining, using a processor, whether the time jump is necessary, comprising:
determining a time difference between the time standard and a leader device time; and
in response to a determination that the time difference is equal to or greater than a threshold value, determining that the time jump is necessary; and

in response to determining that the time jump is necessary:
causing overwriting a sensor data buffer;
providing an indication to unregister one or more follower devices from a leader device;
time jumping the leader device time in response to the time standard; and
causing restarting the collection of the sensor data after the time jump.

6. A computer program product, the computer program product being embodied in a non-transitory computer readable storage medium and comprising computer instructions for:
receiving a time standard;
causing pausing of a collection of sensor data before a time jump;
determining, using a processor, whether the time jump is necessary, comprising:
determining a time difference between the time standard and a leader device time; and
in response to a determination that the time difference is equal to or greater than a threshold value, determining that the time jump is necessary; and

in response to determining that the time jump is necessary:
causing overwriting a sensor data buffer;
providing an indication to unregister one or more follower devices from a leader device;
time jumping the leader device time in response to the time standard; and
causing restarting the collection of the sensor data after the time jump.

7. A system, comprising:
an interface configured to receive a time message from a leader device, wherein the time message is obtained from a registration acknowledgement message sent by the leader device in response to a registration message; and
a processor configured to:
determine whether a time jump is necessary, comprising to:
compare a leader device time obtained from the registration acknowledgement message to a follower device time;
determine a time difference between the leader device time and the follower device time; and
in response to a determination that the time difference is equal to or greater than a threshold value, determine that the time jump is necessary;

in response to determining that the time jump is necessary:
cause overwriting a sensor data buffer;
time jump the follower device time;

receive an unregister indication from the leader device to unregister, wherein the unregister indication comprises a detection of a network socket that has been closed by the leader device;
unregister from the leader device in response to the unregister indication; and
provide the registration message to the leader device requesting registration.

8. The system of claim 7 , wherein the time message from the leader device includes a current leader device time and wherein the follower device time is time jumped to the current leader device time.

9. The system of claim 7 , wherein unregistering from the leader device comprises detecting when a network socket has been closed by the leader device.

10. The system of claim 7 , wherein the processor is further configured to:
provide a registration message to the leader device requesting registration.

11. The system of claim 7 , wherein the processor is further configured to:
provide a registration message to the leader device requesting registration.

12. The system of claim 11 , wherein the processor is further configured to:
receive a registration acknowledgement message sent by the leader device in response to the registration message.

13. The system of claim 12 , wherein determining whether the time jump is necessary in response to the registration acknowledgement message comprises comparing a current leader device time obtained from the registration acknowledgement message to a current follower device time.

14. The system of claim 13 , wherein comparing the current leader device time to the current follower device time comprises:
determining a time difference between the current leader device time and the current follower device time; and
determining whether the time jump is necessary in response to the time difference exceeding a threshold value.

15. The system of claim 7 , wherein t

Assignees

• Lytx Inc

Inventors

• Peter Brendan
• Richardson Larry

Classifications

• H04W56/004 Primary

  compensating for timing error of reception due to propagation delay · CPC title

• H04W4/38

  for collecting sensor information · CPC title

• H04W4/46

  for vehicle-to-vehicle communication [V2V] · CPC title

• H04Q9/00

  Arrangements in telecontrol or telemetry systems for selectively calling a substation from a main station, in which substation desired apparatus is selected for applying a control signal thereto or for obtaining measured values therefrom · CPC title

• H04L67/12

  specially adapted for proprietary or special-purpose networking environments, e.g. medical networks, sensor networks, networks in vehicles or remote metering networks · CPC title