Flexible Pneumatic Actuators: A Comparison between The McKibben and the Straight Fibres Muscles

The prototypes of a McKibben actuator and a straight fibre muscle are presented. Their experimental characteristics are shown. For both kind of typology a mathematical model, able to evaluate the traction force as a function of the contraction ratio and the supply pressure, has been developed, taking into account the geometrical dimensions of the muscles and the mechanical characteristics of the materials. The models have been validated experimentally. Finally, by means of such models, a comparison between the behaviour and performance of the two kinds of actuator has been carried out.