Synchronisation of wearable inertial measurement units based on magnetometer data

Area of Science:

• Biomechanics
• Sensor Technology
• Human Movement Analysis

Background:

• Accurate synchronization of wireless inertial measurement units (IMUs) is crucial for reliable human movement analysis.
• Existing event-based synchronization techniques often lack precision in event generation and accuracy, leading to significant errors in motion estimation.
• Inaccurate synchronization can result in flawed analysis outputs and misinterpretations of movement patterns.

Purpose of the Study:

• To develop and evaluate a novel event-based synchronization technique for wireless IMUs.
• To achieve sub-sample accuracy in synchronization using a magnetic field-based approach.
• To address the limitations of current synchronization methods in human movement analysis.

Main Methods:

• A new event-based synchronization technique utilizing a magnetic field was proposed.
• A testing setup was designed using Shimmer3 inertial measurement units.
• The technique's accuracy and reliability were assessed under specific experimental conditions.

Main Results:

• The proposed magnetic field-based synchronization technique demonstrated high accuracy, with a maximum offset below 2.6 ms for sensors operating at 100 Hz.
• Synchronization was achieved with a required time of 8 seconds based on investigated parameters.
• The method confirmed reliable event generation and detection for wireless IMU synchronization.

Conclusions:

• The novel magnetic field-based synchronization technique offers a reliable solution for wireless IMUs in human movement analysis.
• Further research is recommended to explore the impact of temperature variations on sensor time measurement.
• Testing the approach with IMUs from different manufacturers is suggested to address identified constant offsets in accuracy.