High Specific Power Actuators for Robotic Manipulators

Recent advancements in actuator technology suggest that the implementation of reliable, high power-to-weight ratio pneumatic actuation systems is now possible for robotic platforms. Existing robotic manipulator arms for casualty extraction and patient placement use hydraulic actuation, whereas related robotic prosthetic devices typically use heavy actuator motors. We have developed an alternative solution that employs pneumatic artificial muscles (PAMs). The goal of this study is to identify requirements for a lightweight, high-force robotic manipulator, design the system for heavy lifting capability, and assemble a prototype arm. Following characterization and comparison of different-sized PAM actuators, a proof-of-concept manipulator was constructed. A quasi-static model for the PAM actuators was applied to the system, which includes the Gaylord force, as well as non-linear elastic energy storage. Experimental testing was performed to measure the joint torque and dynamic response of the manipulator, and to validate the model.