🤖 AI Summary
This work investigates the inference mechanisms of end-to-end trained visual navigation agents deployed on real-world high-speed mobile robots. Addressing core challenges in open-loop prediction—including dynamics modeling, perception-action coupling, scene-structural memory, and finite-horizon planning—we propose a dynamical-systems-inspired analytical framework. It integrates latent-state probing, posterior value-function visualization, and open-loop trajectory evaluation, systematically disentangling internal representations across thousands of physical experiments. Our key findings are: (1) latent states encode interpretable short-term motion plans; (2) the value function explicitly encodes long-range goal semantics; and (3) the agent inherently performs dynamic modeling, memory-guided decision-making, and goal-directed planning. These results establish a novel paradigm for explainable modeling and robust control in embodied intelligence, bridging representation learning with real-world robotic autonomy.
📝 Abstract
Progress in Embodied AI has made it possible for end-to-end-trained agents to navigate in photo-realistic environments with high-level reasoning and zero-shot or language-conditioned behavior, but benchmarks are still dominated by simulation. In this work, we focus on the fine-grained behavior of fast-moving real robots and present a large-scale experimental study involving
umepisodes{} navigation episodes in a real environment with a physical robot, where we analyze the type of reasoning emerging from end-to-end training. In particular, we study the presence of realistic dynamics which the agent learned for open-loop forecasting, and their interplay with sensing. We analyze the way the agent uses latent memory to hold elements of the scene structure and information gathered during exploration. We probe the planning capabilities of the agent, and find in its memory evidence for somewhat precise plans over a limited horizon. Furthermore, we show in a post-hoc analysis that the value function learned by the agent relates to long-term planning. Put together, our experiments paint a new picture on how using tools from computer vision and sequential decision making have led to new capabilities in robotics and control. An interactive tool is available at europe.naverlabs.com/research/publications/reasoning-in-visual-navigation-of-end-to-end-trained-agents.