Model Predictive Control of Tensegrity Robots via Contact-Aware Graph Neural Dynamics Model

2026-09-08

AI Summary

该研究通过结合可区分接触检测模块的图神经网络动力学模型和混合MPPI控制策略，解决了张拉整体机器人在复杂地形中的建模与控制难题。

Abstract

Tensegrity robots offer lightweight, compliant mobility over challenging terrain but remain difficult to model and control due to complex contact-rich dynamics and partial observability. This work presents a model predictive path integral (MPPI) controller for a three-bar tensegrity robot driven by a learned graph neural network (GNN) dynamics model. This work first extends prior GNN-based models with a differentiable contact detection module. The extension allows the dynamics model to reason over non-horizontal planar terrains, obstacles, as well as self-collisions. Then, the learned dynamics model and the MPPI controller operate in a closed data-collection loop, iteratively improving model accuracy and control performance. This work further introduces a hybrid MPPI strategy that combines MPPI with turning motion primitives to improve maneuverability. Experiments are performed in MuJoCo across five navigation tasks, which include, wall obstacles, inclines, narrow corridors, low-clearance structures, and a composite 3D obstacle course. The experiments demonstrate that the hybrid MPPI controller operating over the learned GNN dynamics model improves predictive accuracy over a flat-ground baseline model and achieves superior navigation performance compared to $A^*$-based re-planning and MPPI-only variants. Results show that the contact-aware learned dynamics combined with the sampling-based model predictive control enable robust tensegrity navigation in complex, contact-rich environments.

Problem

• Tensegrity Robots
• Contact-Rich Dynamics
• Partial Observability
• Complex Terrain
• Self-Collisions

Innovation

• Model Predictive Path Integral (MPPI)
• Graph Neural Network (GNN) Dynamics Model
• Differentiable Contact Detection
• Hybrid MPPI Strategy