Central Gateway Time Synchronization Backup for Vehicle Domain Controllers

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing time synchronization methods for vehicles, particularly those using the Precision Time Protocol (PTP) stack, face challenges in maintaining accurate time synchronization across domain controllers when the Time-Sensitive Networking (TSN) protocol stack fails, leading to potential time jumps and system crashes.

Innovation Solution

A time synchronization method and device that utilize a central gateway to continuously monitor controller local area network (CAN) messages and clock information messages from a vehicle-mounted telematics device. In case of a TSN protocol stack failure, the central gateway acts as a backup time release source, acquiring and broadcasting a second clock information message to ensure time synchronization among domain controllers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the TSN protocol stack is used for time synchronization in the vehicle, then time synchronization can be achieved under normal conditions, but the system becomes vulnerable to crashes and time jumps when the protocol stack fails

Engineering Contradiction:
Improvetime synchronization reliabilityVSAvoidsystem complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent implements a backup time release source (central gateway) that is pre-configured and ready to take over when the primary time release source (vehicle-mounted telematics device) fails. This cushioning mechanism ensures continuous time synchronization without crashes or time jumps, resolving the reliability issue while maintaining manageable system complexity through a straightforward failover architecture.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The central gateway acts as an intermediary between the vehicle-mounted telematics device and the domain controllers. It monitors the health of the primary time release source and mediates the time synchronization process by stepping in when failures are detected, thus protecting the system from crashes and time jumps without requiring complex modifications to the existing TSN protocol stack.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Device complexity

If the vehicle-mounted telematics device is the sole time release source, then the system structure is simple, but time synchronization fails when the device encounters TSN protocol stack failures

Engineering Contradiction:
Improvesystem structure simplicityVSAvoidtime synchronization continuity
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The central gateway is designed with multi-functionality, serving both as a backup time release source and as a monitor for the primary time release source's health. This universal design allows the system to maintain simplicity in structure while enhancing reliability, as the same gateway component performs multiple critical functions without requiring additional dedicated hardware.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The system pre-configures the central gateway as a standby time release source with all necessary capabilities to take over immediately upon detection of primary source failure. This beforehand cushioning ensures that time synchronization continuity is maintained without compromising system structural simplicity, as the backup capability is integrated into an existing component rather than requiring a separate redundant system.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

3Measurement precision

If the central gateway monitors both CAN messages and clock information messages, then time synchronization accuracy is improved, but the monitoring complexity increases

Engineering Contradiction:
Improvetime synchronization accuracyVSAvoidmonitoring complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent merges the monitoring of CAN messages and clock information messages into a single centralized monitoring process at the central gateway. This combining approach improves time synchronization accuracy by correlating data from both sources simultaneously, while managing monitoring complexity through unified processing logic rather than separate independent monitoring systems.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The central gateway is designed to perform multiple monitoring functions simultaneously - tracking both CAN messages for system status and clock information messages for time synchronization. This multi-functional monitoring capability enhances measurement precision while controlling complexity through integrated processing within a single gateway component.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP4557640A1Time synchronization method and device for vehicle
Publication Date: 2025.05.21 XIAOMI EV TECH CO LTD
  • EP4557640A1 patent drawingFigure 1~2
  • EP4557640A1 patent drawingFigure 3
  • EP4557640A1 patent drawingFigure 4~5

AI summary

A time synchronization method executed by a central gateway includes: continuously monitoring a controller local area network message and a first clock information message both sent by a vehicle-mounted telematics device and both having clock information, in a same time period; acquiring a second clock information message at a current moment according to the monitored first clock information message or the monitored controller local area network message; and sending the second clock information message to a plurality of domain controllers to instruct the plurality of domain controllers to perform a time synchronization according to clock information of the second clock information message.