Validation of a ROS-Based Synchronization System for Biomechanics Gait Labs

Experimental tests in biomechanics are often composed of several systems and devices, each of them providing information that needs to be acquired and processed. Data synchronization is a key factor for test results that need to be properly analyzed, limiting the influence of time delays between the acquired signals. Standard synchronization protocols are applied in different fields, from industry to telecommunications, but the hardware and software requirements for their implementation are normally difficult to be applied in biomechanics laboratories where instrumentation and protocols are likely to be changed over different experiments. Variability of sensors in the market, experimenter's skills, and test schedules hamper the application of robust standardized synchronization protocols, leading to increase post-processing efforts and the protocol steps for data acquisition. We propose a simple and cheap solution for synchronization that can be applied in experimental scenarios such as biomechanics laboratory based on a raspberry used as a trigger-box. This solution aims to easily synchronize data in a ROS-based network with any devices handling analogic trigger signals. The proposed solution is validated by evaluating time metrics in a system composed of several trigger boxes for a multi-sensor system simulation. The performed validation confirms the applicability of this solution for biomechanic tests with a wide margin of tolerance.