LAUSR

Abstract In the present work, the modeling of a human arm has been carried out in its antagonistic actuation mode. Here, the functions of the biceps and triceps muscles are replaced by a pneumatic artificial muscle (PAM) and a spring to lift the required mass. The governing nonlinear equation of motion has been derived considering the system as a single degree of freedom system. Here, the muscle force has been considered as a function of operating pressure, material properties and dimensions of the muscle. The expression for the muscle force is obtained by performing a series of experiments. The approximate solutions, stability and bifurcations have been studied using the second order method of multiple scales (MMS). Further, an experimental setup has been designed and developed to validate the theoretical work. The fundamental frequencies and the responses obtained from the experiments are found to be in good agreement with those obtained using the method of multiple scales. This study will help the bioengineer or researchers to get an idea about the safe operating range of system parameters for various applications of the PAM.