Vehicular ECU Time Synchronization via Single Ethernet Frame

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Solution Overview

Problem

Existing vehicle control systems require multiple Ethernet frames for time synchronization using protocols like PTP, leading to increased overhead and traffic on the Ethernet bus.

Innovation Solution

A vehicular control system that synchronizes time using a single Ethernet frame containing a timestamp and propagation delay corrections, reducing the need for multiple frames and minimizing traffic.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If multiple Ethernet frames are used for time synchronization (PTP protocol), then accurate time synchronization is achieved, but Ethernet traffic overhead increases

Engineering Contradiction:

Improvetime synchronization accuracyVSAvoidEthernet traffic volume

Core Design Contradiction:

Measurement precisionVSQuantity of substance

Solution Approach 1:

The patent combines multiple time synchronization frames into a single Ethernet frame by merging the synchronization request and response data into one communication packet, thereby reducing the total number of frames transmitted while maintaining synchronization accuracy

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The single Ethernet frame is designed to perform multiple functions simultaneously: it carries synchronization timestamps, propagation delay measurements, and correction data, replacing the need for multiple specialized frames in traditional PTP protocols

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Measurement precision

If multiple Ethernet frames are exchanged for propagation delay measurement, then accurate propagation delay is determined, but communication overhead increases

Engineering Contradiction:

Improvepropagation delay measurement accuracyVSAvoidcommunication protocol complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent merges the propagation delay measurement process with the time synchronization frame exchange, allowing delay calculation to occur within the same single frame communication rather than requiring separate measurement frames

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The system performs propagation delay measurement autonomously within the single Ethernet frame by comparing timestamps embedded in the frame itself, eliminating the need for additional dedicated measurement protocols or external calibration procedures

Inventive Principle:

Principle #25Self-service

Data Source

PatentUS12309726B2Vehicular control system with synchronized communication between control units

Publication Date: 2025.05.20 MAGNA ELECTRONICS INC

AI summary

A vehicular control system includes a first electronic control unit (ECU) and a second ECU disposed at a vehicle. The first ECU transmits a first propagation delay frame to the second ECU, which, responsive to receiving the first propagation delay frame, transmits a second propagation delay frame to the first ECU. The first ECU, responsive to receiving the second propagation delay frame, determines a propagation delay based on a time interval between (i) a first point in time when the first ECU transmits the first propagation delay frame to the second ECU and (ii) a second point in time when the first ECU receives the second propagation delay frame from the second ECU. The first ECU transmits a time synchronization frame to the second ECU that includes the determined propagation delay. The second ECU adjusts synchronization of a clock based on the time synchronization frame.