🤖 AI Summary
This work addresses the challenge of modeling cable-driven robots under partial observability, where traditional first-principles approaches often fail. We propose the first general-purpose dynamics simulation framework based on graph neural networks (GNNs), representing rigid bodies as nodes and cables or contacts as edges. The model efficiently predicts system evolution using only partially observable states. By incorporating a co-training mechanism that leverages both simulated and real-world data, our approach significantly enhances robustness to noise and improves generalization. Extensive experiments demonstrate that the method accurately and rapidly reproduces complex dynamical behaviors in both simulation and physical platforms. Furthermore, when integrated into an MPPI controller, it enables efficient closed-loop navigation, validating its superior accuracy and computational efficiency.
📝 Abstract
General-purpose simulators have accelerated the development of robots. Traditional simulators based on first-principles, however, typically require full-state observability or depend on parameter search for system identification. This work presents \texttt{CableRobotGraphSim}, a novel Graph Neural Network (GNN) model for cable-driven robots that aims to address shortcomings of prior simulation solutions. By representing cable-driven robots as graphs, with the rigid-bodies as nodes and the cables and contacts as edges, this model can quickly and accurately match the properties of other simulation models and real robots, while ingesting only partially observable inputs. Accompanying the GNN model is a sim-and-real co-training procedure that promotes generalization and robustness to noisy real data. This model is further integrated with a Model Predictive Path Integral (MPPI) controller for closed-loop navigation, which showcases the model's speed and accuracy.