Modeling and implementation of McKibben actuators for a hopping robot

Abstract

The McKibben artificial-muscle is a pneumatic actuator with a high power-to-weight ratio. This paper presents the implementation of a McKibben actuator to generate dynamic hopping in a one-legged robot. Desired optimization of the hopping robot motivates the development of an improved mathematical model of the McKibben actuators. Accordingly, we improve the accuracy of prior theoretical modeling of the latex forces in the McKibben actuator bladder. We show that the McKibben actuator force is most sensitive to the length of the sheath threads and subsequently present a new technique for estimating this parameter. We compare the theoretical model with experimental results from a low-friction testbed for a range of McKibben actuators.