Design of a Series Elastic Tendon Actuator Based on Gait Analysis for a Walking Assistance Exosuit

Exosuits are wearable robots that enhance a person’s muscular strength from outside the body. Many exosuits use tendon actuators with multiple wires that work similarly to human muscles to minimize user unfamil-iarity caused by the discrepancy between the human body’s degree of freedom and the influence of the mass of the exoskeleton. This paper describes the design of a series elastic tendon actuator (SETA) to be used in exosuits. The SETA performs the agonist and antagonist functions of human muscles using two internal wires as well as elastic elements (springs) to measure the human-robot interaction force and overcome differences in variations occurring between the wires. We defined design objectives and selected the main components based on biomechanical gait analysis to design a small SETA. Moreover, we conducted an experiment to verify the basic performance of our SETA design.