Planning

中文版本：阅读中文版 Introduction The integration of reinforcement learning into end-to-end autonomous driving systems has emerged as a promising direction for improving trajectory planning beyond what supervised learning alone can achieve. However, the direct application of standard RL algorithms to driving tasks faces core challenges: the sim-to-real gap in log-replay environments, the computational bottleneck of online simulation, and the difficulty of defining dense reward signals for continuous trajectory generation. ...

中文版本：阅读中文版 1. Why End-to-End Driving Needs Reinforcement Learning Figure from AlphaDrive: GRPO-based RL for Autonomous Driving Supervised learning—whether through imitation learning or behavior cloning—can only take an autonomous driving system so far. The core limitation is distributional: the training data is drawn from expert demonstrations, and any distributional shift between training and deployment leads to compounding errors. More critically, supervised objectives are misaligned with the true goal of driving. Minimizing the L2 distance to a ground-truth trajectory penalizes safe deviations as harshly as dangerous ones, and provides no mechanism for the model to discover better trajectories than those in the dataset. ...

中文版本：阅读中文版 Introduction The trajectory of autonomous driving architecture has undergone a paradigm shift: from the classical modular pipeline (perception →\to prediction →\to planning →\to control) toward end-to-end systems that map sensory inputs directly to driving actions. This transition is not merely an engineering convenience—it reflects a deep recognition that modular interfaces impose information bottlenecks and that joint optimization across the full stack can yield emergent capabilities invisible to individually optimized modules. ...

中文版本：阅读中文版 Figure from DiffusionDrive: Truncated Diffusion Model for End-to-End Autonomous Driving Autoregressive (AR) trajectory generation — predicting driving trajectories as sequences of discrete tokens, much like language models predict text — has emerged as a powerful paradigm for end-to-end autonomous driving. But how do we turn continuous trajectories into discrete tokens? How do we ensure the tokenized representation preserves enough fidelity for planning? And how does the AR paradigm combine with diffusion and reinforcement learning to produce state-of-the-art results? This article walks through the complete pipeline, from tokenization theory to RL post-training. ...

中文版本：阅读中文版 Figure from DiffusionDrive: Truncated Diffusion Model for End-to-End Autonomous Driving The trajectory planner is the decision-making core of an autonomous driving system. Its task: given the current scene, output a future trajectory that is safe, comfortable, and efficient. Most production systems today use some form of regression — minimizing the distance between predicted and ground-truth trajectories. Yet a growing body of research and engineering evidence suggests this approach has a basic flaw: it assumes the feasible set is convex when it is emphatically not. This article lays out the first-principles argument for why generative approaches (diffusion, autoregressive) are necessary paradigm shifts, not merely improvements. ...