Autonomous Learning Conference Paper 2024

Learning to Control Emulated Muscles in Real Robots: A Software Test Bed for Bio-Inspired Actuators in Hardware

Recent studies have demonstrated the immense potential of exploiting muscle actuator morphology for natural and robust movement - in simulation. A validation on real robotic hardware is yet missing. In this study, we emulate muscle actuator properties on hardware in real-time, taking advantage of modern and affordable electric motors. We demonstrate that our setup can emulate a simplified muscle model on a real robot while being controlled by a learned policy. We improve upon an existing muscle model by deriving a damping rule that ensures that the model is not only performant and stable but also tuneable for the real hardware. Our policies are trained by reinforcement learning entirely in simulation, where we show that previously reported benefits of muscles extend to the case of quadruped locomotion and hopping: the learned policies are more robust and exhibit more regular gaits. Finally, we confirm that the learned policies can be executed on real hardware and show that sim-to-real transfer with real-time emulated muscles on a quadruped robot is possible. These results show that artificial muscles can be highly beneficial actuators for future generations of robust legged robots. Videos: https://sites.google.com/view/emulatedmuscles

Author(s): Schumacher, Pierre and Krause, Lorenz and Schneider, Jan and Büchler, Dieter and Martius, Georg and Haeufle, Daniel
Year: 2024
Month: September
Day: 01
Publisher: IEEE
Bibtex Type: Conference Paper (conference)
Event Place: Heidelberg, Germany
State: Published
URL: https://ieeexplore.ieee.org/document/10719699

BibTex

@conference{PierreLorenz2024,
  title = {Learning to Control Emulated Muscles in Real Robots: A Software Test Bed for Bio-Inspired Actuators in Hardware},
  abstract = {Recent studies have demonstrated the immense potential of exploiting muscle actuator morphology for natural and robust movement - in simulation. A validation on real robotic hardware is yet missing. In this study, we emulate muscle actuator properties on hardware in real-time, taking advantage of modern and affordable electric motors. We demonstrate that our setup can emulate a simplified muscle model on a real robot while being controlled by a learned policy. We improve upon an existing muscle model by deriving a damping rule that ensures that the model is not only performant and stable but also tuneable for the real hardware. Our policies are trained by reinforcement learning entirely in simulation, where we show that previously reported benefits of muscles extend to the case of quadruped locomotion and hopping: the learned policies are more robust and exhibit more regular gaits. Finally, we confirm that the learned policies can be executed on real hardware and show that sim-to-real transfer with real-time emulated muscles on a quadruped robot is possible. These results show that artificial muscles can be highly beneficial actuators for future generations of robust legged robots. Videos: https://sites.google.com/view/emulatedmuscles},
  publisher = {IEEE},
  month = sep,
  year = {2024},
  slug = {pierrelorenz2024},
  author = {Schumacher, Pierre and Krause, Lorenz and Schneider, Jan and B{\"u}chler, Dieter and Martius, Georg and Haeufle, Daniel},
  url = {https://ieeexplore.ieee.org/document/10719699},
  month_numeric = {9}
}