Wearable force sensor with parallel structure for measurement of ground-reaction force

This paper presents development of a wearable force sensor system for human dynamics analysis. Forces and moments are detected by combining responses from eight load cells fabricated on a parallel connection foundation. Finite element method was used for designing preliminary mechanical structures and simulating the mechanical stresses and strains in the load cells. Sensitivity of the load cells in the force sensor was increased by distributing strain gauges on the maximum strain positions. A smart electrical board consisting of signal conditioning circuits, A/D module and a micro-computer controller based communication module was built and integrated into the force sensor. The calibration experiments were performed using a force platform (EFP-S-2KNSA12) as a reference sensor, and in order to investigate interference errors of the sensor, preliminary characterization tests were implemented using a purposely developed characterization workstation. The sensor’s abilities to measure ground-reaction forces with high precision and low interference error were demonstrated.