Physical Modelling of an Antagonistic Pneumatic Pivot Drive

This work deals with the physical modelling of an antagonistic, pneumatic pivot drive, including time dependencies. The developed system includes two pneumatic actuators to control the joint angle. These are a flexible foldable membrane for extension torque and a McKibben-type artificial muscle for flexion torque. Additionally, there are some non-manipulable elements, whose behaviour depends on the joint angle and their derivations. The physical description of the active and passive system components is the main part of this paper. The system is divided into five subsystems which are separately described. The evaluation part shows a comparison between model and real system. For this purpose, different experiments are presented and the suitability of the chosen model is discussed.