Learning Differentiable Tensegrity Dynamics using Graph Neural Networks

Fuente: arXiv
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Hauptverfasser: Chen, Nelson, Wang, Kun, Johnson III, William R., Kramer-Bottiglio, Rebecca, Bekris, Kostas, Aanjaneya, Mridul
Format: Preprint
Veröffentlicht: 2024
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author Chen, Nelson
Wang, Kun
Johnson III, William R.
Kramer-Bottiglio, Rebecca
Bekris, Kostas
Aanjaneya, Mridul
author_facet Chen, Nelson
Wang, Kun
Johnson III, William R.
Kramer-Bottiglio, Rebecca
Bekris, Kostas
Aanjaneya, Mridul
contents Tensegrity robots are composed of rigid struts and flexible cables. They constitute an emerging class of hybrid rigid-soft robotic systems and are promising systems for a wide array of applications, ranging from locomotion to assembly. They are difficult to control and model accurately, however, due to their compliance and high number of degrees of freedom. To address this issue, prior work has introduced a differentiable physics engine designed for tensegrity robots based on first principles. In contrast, this work proposes the use of graph neural networks to model contact dynamics over a graph representation of tensegrity robots, which leverages their natural graph-like cable connectivity between end caps of rigid rods. This learned simulator can accurately model 3-bar and 6-bar tensegrity robot dynamics in simulation-to-simulation experiments where MuJoCo is used as the ground truth. It can also achieve higher accuracy than the previous differentiable engine for a real 3-bar tensegrity robot, for which the robot state is only partially observable. When compared against direct applications of recent mesh-based graph neural network simulators, the proposed approach is computationally more efficient, both for training and inference, while achieving higher accuracy. Code and data are available at https://github.com/nchen9191/tensegrity_gnn_simulator_public
format Preprint
id arxiv_https___arxiv_org_abs_2410_12216
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Learning Differentiable Tensegrity Dynamics using Graph Neural Networks
Chen, Nelson
Wang, Kun
Johnson III, William R.
Kramer-Bottiglio, Rebecca
Bekris, Kostas
Aanjaneya, Mridul
Robotics
Tensegrity robots are composed of rigid struts and flexible cables. They constitute an emerging class of hybrid rigid-soft robotic systems and are promising systems for a wide array of applications, ranging from locomotion to assembly. They are difficult to control and model accurately, however, due to their compliance and high number of degrees of freedom. To address this issue, prior work has introduced a differentiable physics engine designed for tensegrity robots based on first principles. In contrast, this work proposes the use of graph neural networks to model contact dynamics over a graph representation of tensegrity robots, which leverages their natural graph-like cable connectivity between end caps of rigid rods. This learned simulator can accurately model 3-bar and 6-bar tensegrity robot dynamics in simulation-to-simulation experiments where MuJoCo is used as the ground truth. It can also achieve higher accuracy than the previous differentiable engine for a real 3-bar tensegrity robot, for which the robot state is only partially observable. When compared against direct applications of recent mesh-based graph neural network simulators, the proposed approach is computationally more efficient, both for training and inference, while achieving higher accuracy. Code and data are available at https://github.com/nchen9191/tensegrity_gnn_simulator_public
title Learning Differentiable Tensegrity Dynamics using Graph Neural Networks
topic Robotics
url https://arxiv.org/abs/2410.12216