Compliant Worm-Like Robotic Mechanism With Decentrally Controlled Pneumatic Artificial Muscles

When human interacts with a robot, it must be guaranteed that in case of system failure no severe injury can happen. Thus either the control of the robotic device or the actuators or rather the mechanism itself have to necessarily comprise compliance. Compared to other solutions, using pneumatic artificial muscles (PAM) as actuators is an inexpensive way to end up with a mechanism that is compliant. The most challenging part here is the precision of the control, due to the highly non-linear properties of the PAM actuators [1]. This paper presents a prototypic implementation of a robotic mechanism which guarantees inherently compliant and thus human-friendly behavior. The novel idea of the shown concept is the high maneuverability due to cardan joint double axes with centrally fed actuator arrangement that allows more precise control as well as much more modularity than state of the art. A crucial challenge is the development of a smart control of the introduced mechanism, which has a labile equilibrium as a matter of principle.