Onboard Computer Time Sync Validation in Vehicle Networks

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Solution Overview

Problem

Existing systems fail to ensure precise time synchronization between onboard computers in vehicles, which is crucial for the proper functioning of advanced vehicle systems.

Innovation Solution

A method and system for validating time synchronization between onboard computers by comparing time differences between signals and triggering an alarm when deviations exceed a critical value, using a time synchronization validation device that can be embedded or external to the vehicle.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If time synchronization between onboard computers is not validated, then the system operates without additional validation complexity, but time synchronization accuracy deteriorates leading to system reliability issues

Engineering Contradiction:
Improvetime synchronization reliabilityVSAvoidvalidation system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The validation device uses the existing communication network and message exchange mechanisms already present in the vehicle system. The onboard computers themselves participate in the validation process by sending their timestamps through the regular communication channels, making the validation system self-servicing rather than requiring completely separate dedicated validation infrastructure.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The validation device acts as an intermediary that receives messages from multiple onboard computers, extracts their timestamps, and compares them to determine synchronization status. This intermediary approach centralizes the validation logic and allows systematic monitoring of time synchronization across the distributed computer system without requiring direct peer-to-peer validation between all computer pairs.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If time synchronization validation is implemented, then time synchronization accuracy is maintained, but measurement and detection difficulty increases

Engineering Contradiction:
Improvetime difference measurement precisionVSAvoidtime deviation detection difficulty
Core Design Contradiction:
Measurement precisionVSDifficulty of detecting and measuring

Solution Approach 1:

The system establishes a predetermined threshold value for time differences before operation begins. This preliminary setting of acceptance criteria allows the validation device to simply compare measured time differences against the fixed threshold, converting a complex measurement problem into a straightforward comparison operation that is easy to implement and interpret.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The validation approach transforms the abstract concept of time synchronization into a measurable parameter (time difference between timestamps) and further simplifies it by comparing this parameter against a threshold. This parameter transformation makes the invisible time synchronization issue detectable and quantifiable through standard timestamp comparison operations.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If signal emission for time validation is continuous, then time synchronization monitoring is comprehensive, but energy consumption increases

Engineering Contradiction:
Improvesynchronization monitoring reliabilityVSAvoidenergy consumption for signal emission
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The validation approach uses periodic timestamp inclusion within existing regular communication messages rather than continuous dedicated validation signals. Since vehicle communication systems already operate on periodic cycles for normal data exchange, embedding time validation information in these periodic messages achieves continuous monitoring coverage while consuming only the baseline energy already required for normal communication operations.

Inventive Principle:
Principle #19Periodic action

Data Source

PatentEP4288854B1Method and device for validating time synchronization between vehicle on-board computers
Publication Date: 2026.02.25 STELLANTIS AUTO SAS
  • EP4288854B1 patent drawingFigure 1~3

AI summary

The invention relates to a method and a device for validating time synchronization between computers temporally synchronized via a communication network. The time synchronization is validated by comparing at least one time difference between signals transmitted by these computers with a limit value beyond which it is considered that these computers are no longer temporally synchronized with one another.