On-vehicle device and time synchronization method

Patent metadata

Field	Value
Publication number	US-2024333469-A1
Application number	US-202218579609-A
Country	US
Kind code	A1
Filing date	Jun 27, 2022
Priority date	Jul 29, 2021
Publication date	Oct 3, 2024
Grant date	—

Abstract

An on-vehicle device includes: a storage unit configured to store delay time information indicating at least either a first transmission delay time of data from a measurement reference position of a transmission time of the data in an own device, which is the on-vehicle device, to an external position, or a second transmission delay time of data from an external position to a measurement reference position of a reception time of the data in the own device; and a transmission processing unit configured to transmit the delay time information stored in the storage unit to a first other device that performs time synchronization with the own device.

First claim

1 . An on-vehicle device comprising:
a storage unit configured to store delay time information indicating at least either a first transmission delay time of data from a measurement reference position of a transmission time of the data in an own device, which is the on-vehicle device, to an external position, or a second transmission delay time of data from an external position to a measurement reference position of a reception time of the data in the own device; and a transmission processing unit configured to transmit the delay time information stored in the storage unit to a first other device that performs time synchronization with the own device.

2 . The on-vehicle device according to claim 1 ,
wherein the delay time information indicates both the first transmission delay time and the second transmission delay time.

3 . The on-vehicle device according to claim 1 ,
wherein each of the measurement reference positions is located between a MAC processing unit that performs MAC (Medium Access Control) layer processing and a PHY processing unit that performs PHY (Physical) layer processing.

4 . The on-vehicle device according to claim 1 ,
wherein the transmission processing unit transmits the delay time information to the first other device in response to a communication connection being established between the own device and the first other device.

5 . The on-vehicle device according to claim 1 ,
wherein the transmission processing unit transmits information for time synchronization including the delay time information.

6 . The on-vehicle device according to claim 1 ,
wherein the on-vehicle device further includes: a time synchronization unit configured to measure a propagation delay time between the on-vehicle device and the second other device by transmitting and receiving information for time synchronization to and from a second other device, and perform time synchronization with the second other device based on the measured propagation delay time, and the time synchronization unit includes a correction unit configured to correct the propagation delay time based on delay time information indicating at least either a third transmission delay time of data from a measurement reference position of a transmission time of the data in the second other device to an external position, transmitted from the second other device, or a fourth transmission delay time of data from an external position to a measurement reference position of a reception time of the data in the second other device.

7 . A time synchronization method of an on-vehicle device, comprising the steps of:
acquiring delay time information indicating at least either a first transmission delay time of data from a measurement reference position of a transmission time of the data in an own device, which is the on-vehicle device, to an external position, or a second transmission delay time of data from an external position to a measurement reference position of a reception time of the data in the own device; and transmitting the acquired delay time information to another device that performs time synchronization with the own device.

8 . A time synchronization method in an on-vehicle communication system that includes a first on-vehicle device and a second on-vehicle device, comprising:
a step in which the first on-vehicle device transmits delay time information indicating at least either a first transmission delay time of data from a measurement reference position of a transmission time of the data in the first on-vehicle device to an external position, or a second transmission delay time of data from an external position to a measurement reference position of a reception time of the data in the first on-vehicle device; a step in which the second on-vehicle device receives the delay time information transmitted from the first on-vehicle device; a step in which the second on-vehicle device measures the propagation delay time between the second on-vehicle device and the first on-vehicle device by transmitting and receiving information for time synchronization to and from the first on-vehicle device; a step in which the second on-vehicle device corrects the measured propagation delay time based on the delay time information received from the first on-vehicle device; and a step in which the second on-vehicle device performs time synchronization with the first on-vehicle device based on the corrected propagation delay time.

Assignees

• Autonetworks Technologies Ltd
• Sumitomo Wiring Systems
• Sumitomo Electric Industries

Inventors

• Matsumoto Tadashi
• Kitagawa Kazuki
• Inoue Kazuyuki
• Suyama Yojiro
• Izumi Tatsuya
• Tanaka Hideyuki

Classifications

• H04J3/0667 Primary

  Bidirectional timestamps, e.g. NTP or PTP for compensation of clock drift and for compensation of propagation delays (arrangements for monitoring round trip delays in packet switching networks H04L43/0864) · CPC title

• H04L7/0016

  correction of synchronization errors · CPC title

• G04G5/00

  Setting, i.e. correcting or changing, the time-indication (radio-controlled time-pieces G04R) · CPC title

• H04L7/02 Primary

  Speed or phase control by the received code signals, the signals containing no special synchronisation information {(H04L7/0075 takes precedence)} · CPC title