Rational Linkages 

Welcome to the Rational Linkages package documentation, which serves as a reference for the provided tools. This package is a collection of functions for the synthesis, analysis, design, and rapid prototyping of the single-loop rational linkages, allowing one to create 3D-printable collision-free mechanisms synthesised for a given task (set of poses), as in the images below.

The package is developed at the Unit of Geometry and Surveying, University of Innsbruck, Austria. The source code is available as Gitlab repository hosted by UIBK. The installation instructions can be found in the installation manual. STL files of some mechanisms may be found as models on Printables.com.

Since the self-hosted repository (Gitlab, University of Innsbruck) does not allow external users to create issues, please, use the package mirror hosted on Github for submitting issues and feature requests.

For installation-free try-out, run live example of the package in your browser using the Binder service. Click on the badge to start the Jupyter Notebook:

In case of other questions or contributions, please, email the author at: daniel.huczala@snu.ac.kr

Main Features:

Synthesis of single-loop rational linkages for a given task - set of poses or points,
search of full-cycle collision-free design of the linkages,
design of 3D-printable mechanisms,
basic control algorithms for velocity motion planning,
interactive motion design.

The results may look like this Bennett manipulator made by our collaborators from the Department of Robotics, VSB – Technical University of Ostrava. See full video on Youtube.

Contents:

Authors

The package was originally developed by the Unit of Geometry and Surveying, University of Innsbruck (UIBK), Austria. Namely, the following people contributed to the development:

Daniel Huczala (author, maintainer), currently at Robotics Laboratory, Seoul National University, Korea
Hans-Peter Schröcker (supervisor, contributor), UIBK
Martin Pfurner (contributor), UIBK
Andreas Mair (contributor), UIBK
Daren A. Thimm (contributor), UIBK

Citing the Package

If you use the Rational Linkages package in your research, please, cite it as follows:

Huczala, D., Siegele, J., Thimm, D.A., Pfurner, M., Schröcker, HP. (2024). Rational Linkages: From Poses to 3D-Printed Prototypes. In: Lenarčič, J., Husty, M. (eds) Advances in Robot Kinematics 2024. ARK 2024. Springer Proceedings in Advanced Robotics, vol 31. Springer, Cham. DOI: 10.1007/978-3-031-64057-5_27.

@inproceedings{huczala2024linkages,
    title={Rational Linkages: From Poses to 3D-printed Prototypes},
    author={Daniel Huczala and Johannes Siegele and Daren A. Thimm and Martin Pfurner and Hans-Peter Schröcker},
    year={2024},
    booktitle={Advances in Robot Kinematics 2024. ARK 2024},
    publisher={Springer International Publishing},
    url={https://doi.org/10.1007/978-3-031-64057-5_27},
    doi={10.1007/978-3-031-64057-5_27},
}

Preprint available on Arxiv: https://arxiv.org/abs/2403.00558.

Acknowledgements

_{Funded by the European Union. Views and opinions expressed are however those of
the author(s) only and do not necessarily reflect those of the European Union
or the European Research Executive Agency (REA). Neither the European Union
nor the granting authority can be held responsible for them.}

We would like to thank our colleagues outside the Unit of Geometry and Surveying, who contributed to the development of the package and helped with implementation of their algorithms and suggestions. These people are namely:

Johannes Gerstmayr, University of Innsbruck, Austria, for the help with creating the interface to his Exudyn [1] software. More on this in section Dynamics Simulations - Exudyn Integration.
Georg Nawratil, Technical University of Vienna, Austria,
and Zijia Li, Chinese Academy of Sciences, China, for their help with the implementation of the Combinatorial Search Algorithm of collision-free linkages [2]. More on this in section Combinatorial Optimization.
Johannes Siegele, Austrian Academy of Sciences, Austria, for his help with the implementation of the algorithm for motion interpolation of 4 poses. More on this in section Cubic Interpolation of Four Poses.
Severinas Zube, Vilnius University, Lithuania, for his help with implementing the algorithm for motion interpolation of 3D points [3]. More on this in section Motion Interpolation.
Soohyun Kim, Pusan National University, Korea, for her help with the implementation of the Gauss-Legendre curves [4] to represent curved links.

References