Awesome

AcroMonk: A Minimalist Underactuated Brachiating Robot

Description

This project offers an open-source and low-cost kit to test control algorithms for underactuated robots. it implements a brachiation robot platform called AcroMonk which can brachiate robustly over a horizontally laid ladder bar. AcroMonk is the simplest possible underactuated brachiator built using one quasi-direct drive actuator (QDD) and passive grippers. This is the first brachiator with unactuated grippers that can perform more than two brachiation maneuvers. This project offers different control methods for trajectory stabilization which can be studied using the kit. Additionally, it provides a list of components, discusses best practices for implementation, and presents results from experiments with the simulator and the real system. This repository describes the hardware (CAD, Bill Of Materials (BOM) etc.) required to build the physical system and provides the software (URDF models, simulation and controllers) to control it.

Paper and Video References

The work is published in IEEE Robotics and Automation Letters 2023. The hardware experiment video of AcroMonk is also featured as an awesome robot video in IEEE Spectrum Video Friday.

Further links:

• Paper is available on IEEE and arXiv.
• Video is available on youtube.

Documentation

The dynamics of the AcroMonk is explained here. Additionally, mechatronics design, behavior generation and control for the continuous brachiation are described in their respective readme files.

• Mechatronics Design
• Behavior Generation
• Behavior Control
• Software Guide
• Bill Of Materials (BOM)

The CAD file is also provided on grabCAD.com. You can use the 3D viewer from their website to display the 3D model directly within your browser.

• Display AcroMonk in 3D

Authors

• Shivesh Kumar (Project Supervisor)
• Mahdi Javadi (Hardware and Software Maintainer, Trajectory Optimization and Stabilization)
• Daniel Harnack (Software Maintainer, Reinforcement Learning)
• Shubham Vyas (Trajectory Optimization, Hardware Concept)
• Daniel Pizzutilo (Mechatronics Design)
• Paula Stocco (Trajectory Optimization and Stabilization)

Feel free to contact us if you have questions about the test bench. Enjoy!

Contributing

1. Fork it (https://github.com/yourname/yourproject/fork)
2. Create your feature branch (git checkout -b feature/fooBar)
3. Commit your changes (git commit -am 'Add some fooBar')
4. Push to the branch (git push origin feature/fooBar)
5. Create a new Pull Request

Safety Notes

When working with a real system be careful and mind the following safety measures:

• Brushless motors can be very powerful, moving with tremendous force and speed. Always limit the range of motion, power, force and speed using configurable parameters, currently limited supplies, and mechanical design.

• The robot must be placed in a ladder bar cage and kept at least one-meter distance from the acromonk in case of operation.

• Make sure you have access to an emergency stop while doing experiments. Be extra careful while operating in the pure torque control loop.

• The robot is equipped with an onboard Lithium Polymer battery and needs proper care and attention. Make sure that you have all the necessary information for the LiPo batteries.

Acknowledgments

This work has been performed in the M-RoCK project funded by the German Aerospace Center (DLR) with federal funds (Grant Number: FKZ 01IW21002) from the Federal Ministry of Education and Research (BMBF) and is additionally supported with project funds from the federal state of Bremen for setting up the Underactuated Robotics Lab (Grant Number: 201-342-04-2/2021-4-1). The fourth author acknowledges support from the Stardust Reloaded project which has received funding from the European Union’s Horizon 2020 research and innovation program under the Marie Skłodowska-Curie grant agreement No 813644.

License

This work has been released under the BSD 3-Clause License. Details and terms of use are specified in the LICENSE file within this repository. Note that we do not publish third-party software, hence software packages from other developers are released under their very own terms and conditions, e.g. Stable baselines (MIT License) and Tensorflow (Apache License v2.0). If you install third-party software packages along with this repo ensure that you follow each individual license agreement.

Citation

1. Javadi M., Harnack D., Stocco P., Kumar S., Vyas S., Pizzutilo D., Kirchner F., (2022). AcroMonk: A Minimalist Underactuated Brachiating Robot. In: IEEE Robotics and Automation Letters (RA-L), vol. 8, no. 6, pp. 3637-3644, June 2023, doi: 10.1109/LRA.2023.3269296.

@ARTICLE{10106397,
  author={Javadi, Mahdi and Harnack, Daniel and Stocco, Paula and Kumar, Shivesh and Vyas, Shubham and Pizzutilo, Daniel and Kirchner, Frank},
  journal={IEEE Robotics and Automation Letters}, 
  title={AcroMonk: A Minimalist Underactuated Brachiating Robot}, 
  year={2023},
  volume={8},
  number={6},
  pages={3637-3644},
  doi={10.1109/LRA.2023.3269296}}