Novel Considerations on Static Force Modeling of Pneumatic Muscle Actuators

In this paper, a modified static force modeling approach, which is based on fundamental pneumatic muscle actuator (PMA) modeling techniques, is proposed. In addition, the thermal expansion effect is considered as the main cause of the gradual shift in the PMA's force-displacement relationship and the geometric properties, which are being affected by the thermal build-up occurring during the PMA's continuous operation, are incorporated into the static force models. The effects of thermal expansion are documented via experimental studies, and the acquired force-displacement data are utilized for the validation of the proposed modeling method in PMAs of different nominal dimensions and at different test pressures. Finally, an additional evaluation is performed via the comparison of accuracy between the proposed model and the existing geometric static modeling approaches.