Date of Award
5-2026
Document Type
Thesis
Degree Name
Master of Science (MS)
Department
Mechanical Engineering
Committee Chair/Advisor
Dr. Ge Lv
Committee Member
Dr. Gregory Mocko
Committee Member
Dr. Divya Srinivasan
Abstract
Contemporary research suggests that shear force is a major contributor to discomfort and pressure injury. However, the variation of shear forces during human-exoskeleton interaction dynamics is a highly unexplored field. The high cost of commercial triaxial force sensors may be a major factor in the notable lack of research in this field. Therefore, in this paper, we present a low-cost, 3D-printed triaxial force sensor designed specifically to measure the triaxial interaction forces between an exoskeleton and its user. The triaxial force sensor uses Carbon-Black/Silicone Rubber (CB/SR) strings to measure shear forces, whereas the normal force is measured with a Force Sensitive Resistor (FSR). The sensor is calibrated using a simple position-servo-based mechanism, and its response is characterized using the Static Decoupling Model. The sensor is validated using a setup in which known weights pull each axis through a pulley. The Normalised Mean Absolute Error of the sensor ranges from 7.45% to 19.65%, indicating that the sensor is substantially accurate. Also, the sensor achieves the target shear force sensitive range of 1.22 - 9.14 N in many of the tested directions and exceeds the minimum required range of 1.22 - 3.046 N for measuring discomfort. Human Trials were also performed, in which the sensor response was tested across six able-bodied subjects performing activities such as walking, lunges, squats, sit-to-stand, and stair climb. The results from the human trials indicate good sensor response within the force ranges observed in previous research across almost all activities. The sensor is 84% cheaper than commercial alternatives but offers comparatively lower performance in terms of non-linearity, hysteresis, and repeatability. Therefore, the sensor has strong potential as a low-cost triaxial force sensor for measuring variations in triaxial forces during Human-Exoskeleton Dynamics.
Recommended Citation
Sarvathullah, Hamdan Khan, "Development of Low-Cost Triaxial Force Sensor for Measurement of Human-Exoskeleton Interaction Forces" (2026). All Theses. 4788.
https://open.clemson.edu/all_theses/4788
Author ORCID Identifier
https://orcid.org/0009-0004-9778-0265
Included in
Acoustics, Dynamics, and Controls Commons, Biomechanical Engineering Commons, Biomedical Devices and Instrumentation Commons, Controls and Control Theory Commons, Electro-Mechanical Systems Commons, Orthotics and Prosthetics Commons, Sports Sciences Commons