Design, Development, and Testing of Torque and Angle Measurement System for a Traction Machine

Abstract

This thesis presents the development of a traction measuring system designed to evaluate the interaction between shoes and playing surfaces to prevent lower extremity injuries. The interaction between shoes and playing surfaces has been identified as a key risk factor for lower extremity injuries. The traction system was designed and built with an advanced mechatronics interface which is going to be used as an add-on to an existing manually operated EXETER S2T2 traction machine utilized by Aspetar. The components of the traction machine such as the electronics interface, operating software, and connecting parts were developed in the workshop. The mechanical interactions such as rotational torque, and angular displacement, between the shoes and the natural grass as well as artificial grass of playing surfaces were measured. The values of torque were calculated at various applied loads within 90o angles for inward and outward rotations, and it was plotted against the angular displacement, and speed of rotation. The peak torque obtained for the Nike Tiempo shoe has the highest traction of 32.44 Nm for outward rotation on natural grass (NG) and the lowest of 25.89 Nm for inward rotation on artificial grass (AG) which are considerably different for various loading and speed conditions. The result analysis shows the improved efficiency and ability of the mechatronic add-on over the existing manually operated traction measuring machine. A numerical model was developed using the modified Bouc-Wen mode parameters for the calculation of torque with various conditions. The numerical results show that the rotational stiffness can be represented by sub-systems and each with their own properties. As the loading condition or speed changes, the model's degree of freedom also changes which leads to a reduction in sudden change in stiffness. The traction measuring system has the potential to contribute significantly to the understanding of lower extremity injury mechanics and to help design footwear and playing surfaces that minimize injury risk. The results of this study will be useful for sports medicine practitioners, footwear designers, and sports organizations looking to reduce the incidence of lower extremity injuries in athletes.