V2X Timestamp Offset Compensation for Reliable Scene Interpretation

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Solution Overview

Problem

Inaccurate time synchronization in vehicle-to-everything (V2X) communications leads to position errors and scene interpretation failures due to unsynchronized time stamps in V2X messages, which are not accepted by other V2X units and hinder effective message processing.

Innovation Solution

Each V2X unit determines a time compensation offset for each sender based on the difference between the sender's timestamps and its ego time, applying this offset to adjust message timestamps for accurate scene interpretation and system control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If V2X units synchronize time to GNSS or GPS time, then time synchronization accuracy is improved, but position error and scene interpretation failure occur when time synchronization is inaccurate

Engineering Contradiction:
Improvetime synchronization accuracyVSAvoidmessage acceptance reliability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent replaces the mechanical/GNSS-based time synchronization system with a network-based time compensation system. Instead of relying solely on GNSS time stamps, the system uses message exchange between V2X units to calculate time offsets and compensate for synchronization errors, substituting the physical time synchronization mechanism with a computational correction approach

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the time parameter by introducing time compensation offsets. The system calculates the offset between expected and actual message arrival times, then applies this offset to compensate for synchronization errors, effectively transforming the time parameter to achieve accurate scene interpretation despite GNSS time synchronization inaccuracies

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If time compensation offset is calculated for each sender, then message processing accuracy is improved, but system complexity increases

Engineering Contradiction:
Improvemessage processing accuracyVSAvoidtime synchronization system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent segments the time compensation process by maintaining separate time compensation offsets for each sender. Instead of using a single global offset, the system calculates and stores individual offsets for messages from different senders, allowing precise compensation for each communication source while managing complexity through organized data structures

Inventive Principle:
Principle #1Segmentation

3Measurement precision

If time compensation offset is applied to all messages from a sender, then scene interpretation accuracy is improved, but processing time increases

Engineering Contradiction:
Improvescene interpretation accuracyVSAvoidmessage processing time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent applies time compensation offsets in advance when messages are received from senders. By pre-calculating and storing the time compensation offset for each sender, the system prepares the correction data beforehand, so that when messages need to be processed for scene interpretation, the compensation is already available and can be applied efficiently without adding significant processing delay

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP4454168B1Apparatus and method for time synchronization in v2x networks
Publication Date: 2025.11.05 AUMOVIO SYSTEMS INC
  • EP4454168B1 patent drawingFigure 1
  • EP4454168B1 patent drawingFigure 2
  • EP4454168B1 patent drawingFigure 3

AI summary

The assumption that every participating vehicle control unit (VCU) or engine control unit (ECU) in a V2X network is synchronized to GNSS time or GPS time (or some other time base) is discarded. An error is assumed for every time entry. For all messages received from a dedicated communication node, a time compensation offset is determined.