Learning Scalable Multi-Agent Coordination by Spatial Differentiation for Traffic Signal Control
This addresses traffic optimization for transportation systems, offering a scalable and decentralized approach, though it appears incremental as it builds on existing coordination methods.
The paper tackles the problem of achieving global optimal traffic efficiency in large-scale road networks by proposing a multi-agent coordination framework for traffic signal control, which uses spatial differentiation to amend rewards and achieves state-of-the-art performance without centralized settings.
The intelligent control of the traffic signal is critical to the optimization of transportation systems. To achieve global optimal traffic efficiency in large-scale road networks, recent works have focused on coordination among intersections, which have shown promising results. However, existing studies paid more attention to observations sharing among intersections (both explicit and implicit) and did not care about the consequences after decisions. In this paper, we design a multiagent coordination framework based on Deep Reinforcement Learning methods for traffic signal control, defined as γ-Reward that includes both original γ-Reward and γ-Attention-Reward. Specifically, we propose the Spatial Differentiation method for coordination which uses the temporal-spatial information in the replay buffer to amend the reward of each action. A concise theoretical analysis that proves the proposed model can converge to Nash equilibrium is given. By extending the idea of Markov Chain to the dimension of space-time, this truly decentralized coordination mechanism replaces the graph attention method and realizes the decoupling of the road network, which is more scalable and more in line with practice. The simulation results show that the proposed model remains a state-of-the-art performance even not use a centralized setting. Code is available in https://github.com/Skylark0924/Gamma Reward.