In-Vehicle Time Synchronization with Event-Triggered Delay Updates
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing in-vehicle network systems face increased processing load due to frequent updates of data propagation delay times, disrupting smooth time synchronization and vehicle operation control.
Innovation Solution
An in-vehicle device that performs time synchronization based on data propagation delay times, detects update events, and requests time information only when necessary, reducing the frequency of update processing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If data propagation delay time is periodically updated in accordance with IEEE 802.1 protocol, then time synchronization accuracy is improved, but processing load increases and other processing cannot be performed smoothly
Solution Approach 1:
The patent applies periodic action by updating propagation delay time only at specific intervals triggered by update events rather than continuously or at fixed periodic intervals. The processing unit determines whether update processing has elapsed a predetermined period since the last update, and only performs updates when this condition is met, thereby reducing processing frequency while maintaining synchronization accuracy.
Solution Approach 2:
The system employs self-service mechanisms where the processing unit autonomously monitors for update events and independently determines when propagation delay time updates are necessary. The device serves itself by tracking elapsed periods and triggering updates only when predetermined conditions are satisfied, eliminating the need for external continuous intervention and reducing overall processing load.
2Measurement precision
If propagation delay time update processing is performed frequently, then time synchronization precision is improved, but device complexity and processing overhead increase
Solution Approach 1:
The patent implements dynamics by making the propagation delay time update process adaptive rather than static. The processing unit dynamically adjusts update timing based on detected update events and elapsed periods, transitioning between update and non-update states according to predetermined conditions. This dynamic approach maintains precision when needed while reducing overhead during stable periods.
Data Source
AI summary
An in-vehicle device includes: a processing unit configured to perform time synchronization between own device, which is the in-vehicle device, and another device, which is another in-vehicle device, based on a data propagation delay time between the other device and the own device, and detect occurrence of an update event regarding the propagation delay time, wherein in a case where the processing unit detects occurrence of the update event, the processing unit requests time information used for updating the propagation delay time from the other device.