Sensor Time Synchronization Using Propagation-Aware Clock Correction

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional time synchronization methods for sensors struggle to account for changes in the positional relationship among sensors, leading to difficulties in determining whether time deviations are due to clock deviations or changes in propagation time.

Innovation Solution

A detection apparatus and method that include an internal clock, an oscillator unit, an oscillation receiver unit, a measurement unit, a determination unit, and a correction unit. This apparatus measures the time from oscillation generation to detection, determines a mode based on this time, and decides whether to correct the internal clock based on a reference time, thereby synchronizing times while considering the positional relationship among sensors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional time synchronization methods are used to synchronize sensor times, then time deviation can be detected, but it is difficult to determine whether the deviation is caused by clock deviation or change in propagation time due to positional relationship changes

Engineering Contradiction:
Improvetime synchronization precisionVSAvoidinformation on cause of time deviation
Core Design Contradiction:
Measurement precisionVSLoss of information

Solution Approach 1:

The patent segments the time synchronization problem into two distinct scenarios: pre-installation mode (sensors in fixed positional relationship) and post-installation mode (sensors in installed positional relationship). By dividing the synchronization process into these segments, the system can apply different reference times appropriate to each scenario, thereby identifying whether time deviation is caused by clock issues or propagation time changes due to positional changes.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent performs preliminary time synchronization in the pre-installation mode before the sensors are installed in their final positions. This preliminary action establishes a baseline reference time when the positional relationship is fixed and known. By comparing post-installation synchronization results against this pre-established baseline, the system can determine whether time deviations are due to clock problems or changes in propagation time caused by installation.

Inventive Principle:
Principle #10Preliminary action

2Ease of operation

If time synchronization is performed without considering positional relationship, then synchronization can be achieved, but accuracy is reduced when sensors are rearranged or reinstalled

Engineering Contradiction:
Improvesynchronization operation simplicityVSAvoidtime synchronization accuracy
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent implements a dynamic time synchronization approach that automatically adapts to the operational mode (pre-installation or post-installation) based on the current state of the sensors. The system dynamically selects the appropriate reference time and synchronization method according to whether sensors are being initially configured or have been installed and potentially rearranged, thereby maintaining high accuracy across different operational scenarios without complicating the user interface.

Inventive Principle:
Principle #15Dynamics

3Reliability

If internal clocks are corrected based on all time deviations, then synchronization is maintained, but unnecessary corrections are performed when deviations are due to positional changes

Engineering Contradiction:
Improvetime synchronization reliabilityVSAvoidcorrection process simplicity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent applies local quality by using different reference times and correction strategies for different operational modes. In pre-installation mode, one type of reference time is used, while in post-installation mode, a different reference time is applied. This localized approach ensures that corrections are only performed when actually needed (when there is genuine clock deviation), rather than unnecessarily adjusting clocks when time deviations are simply due to changed propagation times from repositioning sensors.

Inventive Principle:
Principle #3Local quality

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The solution effectively synchronizes sensor times by distinguishing between clock deviations and positional changes, ensuring accurate detection of abnormal oscillations and maintaining high precision in identifying the source of oscillations.

Implementation Method 1

an oscillator unit that generates oscillation every time a temporal condition is met; an oscillation receiver unit that detects oscillation

Methodology Applied
Scientific EffectOscillation generation and propagation: Sound

Data Source

PatentEP4567549A1Detection apparatus, time synchronization method, non- transitory computer readable recording medium, and detection system
Publication Date: 2025.06.11 YOKOGAWA ELECTRIC CORP
  • EP4567549A1 patent drawingFigure 1
  • EP4567549A1 patent drawingFigure 2~3
  • EP4567549A1 patent drawingFigure 4~5

AI summary

A detection apparatus (10) according to one embodiment includes an internal clock, an oscillator unit (11) that generates oscillation every time a temporal condition is met, an oscillation receiver unit (12) that detects oscillation, a measurement unit (142) that measures a time from when the oscillator unit (11) generates the oscillation to when the oscillation receiver unit (12) detects the oscillation, a determination unit (141) that determines a mode based on whether a time that is measured by the measurement unit (142) is longer than a predetermined interval time, and a correction unit (143) that determines whether to perform correction of deviation of the internal clock based on a reference time when it is determined that the mode is a specific mode, and corrects the internal clock when determining that the correction is performed.