Design and characterization of 3d printed, open-source actuators for legged locomotion
Impressive animal locomotion capabilities are mediated by the co-evolution of the skeletal morphology and muscular properties. Legged robot performance would also likely benefit from the co-optimization of actuators and leg morphology. However, development of custom actuators for legged robots is expensive and time consuming, discouraging application-specific actuator optimization. This paper presents open source designs for two quasi-direct-drive actuators with performance regimes appropriate for an 8–15 kg robot, built from off the shelf and 3D-printed components for less than $200 USD each. The mechanical, electrical, and thermal properties of each actuator are characterized and compared to bench- mark data. Actuators subjected to 420k strides of gait data experienced only a 2% reduction in efficiency and 26 mrad in backlash growth, demonstrating viability for rigorous and sustained research applications. We present a thermal solution that nearly doubles the thermally-driven torque limits of our plastic actuator design. The performance results are comparable to traditional metallic actuators for use in high-speed legged robots of the same scale. These 3D printed designs demonstrate an approach for designing and characterizing low-cost, highly customizable and reproducible actuators, democratizing the field of actuator design and enabling co-design and optimization of actuators and robot legs.
BibTex:
@article{Urs20223DP,author = {Karthik Urs and Challen {Enninful Adu} and Elliott J. Rouse and Talia Y. Moore},journal = {IEEE IROS},title = {Design and Characterization of 3D Printed, Open-Source Actuators for Legged Locomotion},year = {2022},doi = {10.1109/IROS47612.2022.9981940}}