A Hierarchical Reinforcement Learning Framework with Spatial-Temporal Graph Attention for Autonomous Driving Decision-Making and Control
This paper presents a hierarchical framework that integrates spatial-temporal graph attention network (ST-GAT) with reinforcement learning for decision and control of autonomous driving. Inspired by the principles of human cognition, the framework decomposes the driving task into two complementary levels: a high-level trajectory planning module that utilizes the soft actor-critic (SAC) algorithm within the Frenet coordinate system, and a low-level tracking control module based on the worst-case soft actor-critic (WCSAC) strategy. This hierarchical decomposition improves policy stability and sample efficiency by decoupling strategic trajectory planning from reactive control execution. Unlike previous methods, the proposed ST-GAT module enables explicit scene understanding by modeling surrounding vehicles and their interactions as a spatial-temporal graph structure. Through attention-based aggregation, the system dynamically captures road geometry and agent behaviors directly from online sensor observations, enabling mapless situational reasoning. Experimental results show that the proposed framework achieves success rates of 92.33% and 97.00% in the roundabout and five-way intersection scenarios in the CARLA simulator.