An Open-Source Modular Treadmill for Dynamic Force Measurement with Load Dependant Range Adjustment

TL;DR

This paper introduces a modular, open-source treadmill designed for precise ground reaction force measurement in gait analysis, adaptable for humans and small robots, with detailed design, calibration, and performance evaluation.

Contribution

It presents a novel, adjustable-force-range treadmill with a comprehensive design methodology, calibration process, and performance characterization for gait analysis applications.

Findings

Force measurement accuracy ≤ 5.6N

Center of pressure accuracy ≤ 13mm

Natural frequency of 170Hz

Abstract

Ground reaction force sensing is one of the key components of gait analysis in legged locomotion research. To measure continuous force data during locomotion, we present a novel compound instrumented treadmill design. The treadmill is 1.7m long, with a natural frequency of 170Hz and an adjustable range that can be used for humans and small robots alike. Here, we present the treadmill's design methodology and characterize it in its natural frequency, noise behavior and real-life performance. Additionally, we apply an ISO 376 norm conform calibration procedure for all spatial force directions and center of pressure position. We achieve a force accuracy of $\leq$5.6N for the ground reaction forces and $\leq$13mm in center of pressure position.