Motion Capture System Satellite Clock Synchronization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing motion capture systems face limitations in accuracy and portability, with optical systems being expensive and restrictive, and inertial measurement unit (IMU) systems prone to drift and synchronization issues.
Innovation Solution
A computer-implemented method using a satellite network for clock synchronization across multiple motion sensing units, combined with disparate sensors and pre-processing algorithms like non-linear least squares estimation and extended Kalman filters, to generate accurate kinematic models of body motion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If optical systems with many cameras are used, then measurement precision is improved, but device complexity and cost increase
Solution Approach 1:
The patent replaces the optical mechanical system (multiple cameras) with an inertial measurement system using IMUs and satellite-based timing. Each motion sensing unit independently measures acceleration and orientation without requiring optical line-of-sight, eliminating the complex camera infrastructure while maintaining measurement capability through inertial sensors and GPS/ Galileo timing synchronization.
Solution Approach 2:
Each motion sensing unit operates independently with its own IMU, clock, and processing capabilities. The units self-synchronize using satellite timing signals and autonomously generate motion data points without requiring centralized control or coordination, reducing overall system complexity while maintaining measurement precision.
2Ease of operation
If inertial measurement unit systems are used, then portability is improved, but measurement precision deteriorates due to drift and synchronization issues
Solution Approach 1:
The patent introduces satellite-based timing signals (GPS/Galileo) as an intermediary reference that provides a common time base for all motion sensing units. This external timing intermediary enables precise synchronization between distributed IMUs without requiring complex inter-unit communication protocols, eliminating drift accumulation and improving measurement accuracy while maintaining portability.
3Measurement precision
If multiple sensors are distributed across the body, then measurement coverage is improved, but clock synchronization difficulty increases
Solution Approach 1:
The patent uses a universal satellite timing signal that serves all motion sensing units simultaneously. Each unit independently receives and processes the same satellite timing broadcasts, providing a common reference frame for all sensors across the body. This universal timing approach simplifies synchronization compared to peer-to-peer methods, as each unit can autonomously align its clock to the same external standard without complex inter-unit coordination.
Data Source
AI summary
A motion capture system and method are provided. In a motion capture method, a plurality of motion datasets are accessed. Each motion dataset is associated with a motion sensing unit at which timestamped motion data points of that motion dataset are generated, each motion sensing unit is configured to be in physical contact with a different part of a body of interest. Each timestamped motion data point is timestamped at the motion sensing unit at which it is generated using a clock time that is synchronized across the plurality of motion sensing units. The timestamped motion data points are processed to generate a kinematic model which describes motion of the respective parts of the body of interest.