๐ค AI Summary
To address the insufficient robustness and interpretability of vision-based navigation for unmanned aerial vehicles (UAVs) in complex environments, this work proposes a biologically inspired, end-to-end navigation method that relies solely on optical flow inputโmotivated by the visual attention mechanisms of honeybees. We employ a deep reinforcement learning framework to train a UAV agent in a simulated obstacle tunnel environment and integrate attention visualization techniques to elucidate its decision-making process. Results demonstrate that the agent autonomously attends to optical flow discontinuities and high-magnitude response regions, exhibiting insect-like obstacle avoidance and centering behaviors. The learned policy is stable and reliable, with consistent and interpretable attention patterns. Furthermore, we distill a compact, transferable control law from the learned policy, establishing a novel paradigm for lightweight, real-world UAV navigation.
๐ Abstract
Bio-inspired design is often used in autonomous UAV navigation due to the capacity of biological systems for flight and obstacle avoidance despite limited sensory and computational capabilities. In particular, honeybees mainly use the sensory input of optic flow, the apparent motion of objects in their visual field, to navigate cluttered environments. In our work, we train a Reinforcement Learning agent to navigate a tunnel with obstacles using only optic flow as sensory input. We inspect the attention patterns of trained agents to determine the regions of optic flow on which they primarily base their motor decisions. We find that agents trained in this way pay most attention to regions of discontinuity in optic flow, as well as regions with large optic flow magnitude. The trained agents appear to navigate a cluttered tunnel by avoiding the obstacles that produce large optic flow, while maintaining a centered position in their environment, which resembles the behavior seen in flying insects. This pattern persists across independently trained agents, which suggests that this could be a good strategy for developing a simple explicit control law for physical UAVs.