🤖 AI Summary
This work addresses the challenge that existing physics-informed neural motion planning methods often converge to local minima and fail to ensure global consistency in high-dimensional, complex environments. To overcome this limitation, the authors propose Hierarchical Neural Time Fields (H-NTFields), which, for the first time, incorporate sparse roadmap priors as weak supervision into physics-informed neural networks. By integrating Eikonal equation constraints with PDE-based regularization, H-NTFields simultaneously preserve local geometric accuracy and capture global topological structure. The method enforces upper and lower bounds on travel time, substantially enhancing planning robustness and global consistency in multi-room settings. Extensive experiments across 18 Gibson scenes and real-world robotic platforms demonstrate its superiority over current physics-informed approaches, while supporting efficient amortized inference.
📝 Abstract
The motion planning problem requires finding a collision-free path between start and goal configurations in high-dimensional, cluttered spaces. Recent learning-based methods offer promising solutions, with self-supervised physics-informed approaches such as Neural Time Fields (NTFields) solving the Eikonal equation to learn value functions without expert demonstrations. However, existing physics-informed methods struggle to scale in complex, multi-room environments, where simply increasing the number of samples cannot resolve local minima or guarantee global consistency. We propose Hierarchical Neural Time Fields (H-NTFields), a weakly-supervised framework that combines weak supervision from sparse roadmaps with physics-informed PDE regularization. The roadmap provides global topological anchors through upper and lower bounds on travel times, while PDE losses enforce local geometric fidelity and obstacle-aware propagation. Experiments on 18 Gibson environments and real robotic platforms show that H-NTFields substantially improves robustness over prior physics-informed methods, while enabling fast amortized inference through a continuous value representation.