Static Force Model of Pneumatic Artificial Muscles

Pneumatic actuators convert pneumatic energy into mechanical motion. This motion can be linear or rotary. Linear motion is feasible with pneumatic cylinders (e. g. single-acting cylinder, double-acting cylinder, rodless cylinder) and pneumatic artificial muscles (PAMs). Pneumatic artificial muscle is the newest and most promising type of pneumatic actuators. PAM is a membrane that expands radially and contracts axially when inflated, while generating high pulling forces along the longitudinal axis. The force and motion produced by PAM are linear and unidirectional. Different designs of PAM have already been developed. Recently Fluidic Muscle manufactured by Festo Company and Shadow Air Muscle manufactured by Shadow Robot Company are the most popular and commercially available. The most often mentioned characteristic of PAMs is the force as a function of pressure and contraction. In this paper our newest function approximation for the force generated by Fluidic Muscles is shown that can be generally used for different muscles made by Festo Company.