See Less, Drive Better: Generalizable End-to-End Autonomous Driving via Foundation Models Stochastic Patch Selection
Amir Mallak, Erfan Aasi, Shiva Sreeram, Tsun-Hsuan Wang, Daniela Rus, Alaa Maalouf
TL;DR
The paper addresses redundancy in patch‑level features extracted from foundation models for end‑to‑end autonomous driving. It introduces Stochastic Patch Selection (SPS), which randomizes the subset of patch descriptors fed to the policy while preserving spatial layout, reducing compute by about $2.4\times$ and improving OOD performance by an average of $6.2\%$ (up to $20.4\%$ in hard cases). Empirical analyses show patch features lie in a low‑rank subspace with pervasive cross‑patch correlations; SPS exploits this by training on diverse, coherent views that emphasize invariant cues. The approach transfers from simulation to a real vehicle without tuning and can be paired with latent space text augmentation to further boost robustness, offering a practical, architecture‑agnostic pathway to robust FM‑based driving systems.
Abstract
Recent advances in end-to-end autonomous driving show that policies trained on patch-aligned features extracted from foundation models generalize better to Out-of-Distribution (OOD). We hypothesize that due to the self-attention mechanism, each patch feature implicitly embeds/contains information from all other patches, represented in a different way and intensity, making these descriptors highly redundant. We quantify redundancy in such (BLIP2) features via PCA and cross-patch similarity: $90$% of variance is captured by $17/64$ principal components, and strong inter-token correlations are pervasive. Training on such overlapping information leads the policy to overfit spurious correlations, hurting OOD robustness. We present Stochastic-Patch-Selection (SPS), a simple yet effective approach for learning policies that are more robust, generalizable, and efficient. For every frame, SPS randomly masks a fraction of patch descriptors, not feeding them to the policy model, while preserving the spatial layout of the remaining patches. Thus, the policy is provided with different stochastic but complete views of the (same) scene: every random subset of patches acts like a different, yet still sensible, coherent projection of the world. The policy thus bases its decisions on features that are invariant to which specific tokens survive. Extensive experiments confirm that across all OOD scenarios, our method outperforms the state of the art (SOTA), achieving a $6.2$% average improvement and up to $20.4$% in closed-loop simulations, while being $2.4\times$ faster. We conduct ablations over masking rates and patch-feature reorganization, training and evaluating 9 systems, with 8 of them surpassing prior SOTA. Finally, we show that the same learned policy transfers to a physical, real-world car without any tuning.
