Cloud-edge collaborative computing (CECC) facilitates the sharing of computing resources by collaboratively scheduling tasks among servers, thereby maximizing task execution efficiency. Task scheduling and resource allocation (TS-RA) are two interrelated issues that significantly affect the efficient utilization of computing resources. In this paper, we decouple the joint optimization problem of TS-RA and propose a novel model based on multi-agent reinforcement learning (TRMARL), which is applicable to distributed task scheduling and resource allocation in a heterogeneous CECC system. TRMARL consists of two modules: 1) the task scheduling module, where we introduce a value factorization algorithm to maximize joint rewards of distributed scheduling actions; 2) the resource allocation module, where we present a proximal policy optimization (PPO) algorithm based mechanism to optimize resource allocation. TRMARL efficiently captures the state difference among heterogeneous servers through a graph attention network-based recurrent deep Q-network (GAT-based recurrent-DQN) architecture and learns different strategies for heterogeneous services through a multi-expert schema. The experimental results demonstrate that TRMARL effectively improves the task completion rate, reduces average system latency, and enhances convergence stability in a heterogeneous CECC system.

Reward design is a key component of deep reinforcement learning (DRL), yet some tasks and designer’s objectives may be unnatural to define as a scalar cost function. Among the various techniques, formal methods integrated with DRL have garnered considerable attention due to their expressiveness and flexibility in defining the reward and requirements for different states and actions of the agent. Nevertheless, the exploration of leveraging Signal Temporal Logic (STL) for guiding multi-agent reinforcement learning (MARL) reward design is still limited. The presence of complex interactions, heterogeneous goals, and critical safety requirements in multi-agent systems exacerbates this challenge. In this paper, we propose a novel STL-guided multi-agent reinforcement learning framework. The STL requirements are designed to include both task specifications according to the objective of each agent and safety specifications. The robustness values from checking the states against STL specifications are leveraged to generate rewards. We validate our approach by conducting experiments across various testbeds. The experimental results demonstrate significant performance improvements compared to MARL without STL guidance, along with a remarkable increase in the overall safety rate of the multi-agent systems.

Hybrid traffic which involves both autonomous and human-driven vehicles would be the norm of the autonomous vehicles’ practice for a while. On the one hand, unlike autonomous vehicles, human-driven vehicles could exhibit sudden abnormal behaviors such as unpredictably switching to dangerous driving modes—putting its neighboring vehicles under risks; such undesired mode switching could arise from numbers of human driver factors, including fatigue, drunkenness, distraction, aggressiveness, and so on. On the other hand, modern vehicle-to-vehicle (V2V) communication technologies enable the autonomous vehicles to efficiently and reliably share the scarce run-time information with each other [ 1 ]. In this article, we propose, to the best of our knowledge, the first efficient algorithm that can (1) significantly improve trajectory prediction by effectively fusing the run-time information shared by surrounding autonomous vehicles, and can (2) accurately and quickly detect abnormal human driving mode switches or abnormal driving behavior with formal assurance without hurting human drivers’ privacy. To validate our proposed algorithm, we first evaluate our proposed trajectory predictor on NGSIM and Argoverse datasets and show that our proposed predictor outperforms the baseline methods. Then through extensive experiments on SUMO simulator, we show that our proposed algorithm has great detection performance in both highway and urban traffic. The best performance achieves detection rate of 97.3%, average detection delay of 1.2 s, and 0 false alarm.

The recent advancements in wireless technology enable connected autonomous vehicles (CAVs) to gather information about their environment by vehicle-to-vehicle (V2V) communication. In this work, we design an information-sharing-based multi-agent reinforcement learning (MARL) framework for CAVs, to take advantage of the extra information when making decisions to improve traffic efficiency and safety. The safe actor-critic algorithm we propose has two new techniques: the truncated$\mathcal{Q}$-function and safe action mapping. The truncated$\mathcal{Q}$-function utilizes the shared information from neighboring CAVs such that the joint state and action spaces of the$\mathcal{Q}$-function do not grow in our algorithm for a large-scale CAV system. We prove the bound of the approximation error between the truncated-$\mathcal{Q}$and global$Q$-functions. The safe action mapping provides a provable safety guarantee for both the training and execution based on control barrier functions. Using the CARLA simulator for experiments, we show that our approach improves the CAV system’s efficiency in terms of average velocity and comfort under different CAV ratios and different traffic densities. We also show that our approach avoids the execution of unsafe actions and always maintains a safe distance from other vehicles. We construct an obstacle-at-corner scenario to show that the shared vision can help CAVs to observe obstacles earlier and take action to avoid traffic jams. The experiment video is on https://songyanghan.github.io/cavmarl/.

Communication technologies enable coordination among connected and autonomous vehicles (CAVs). However, it remains unclear how to utilize shared information to improve the safety and efficiency of the CAV system in dynamic and complicated driving scenarios. In this work, we propose a framework of constrained multi-agent reinforcement learning (MARL) with a parallel Safety Shield for CAVs in challenging driving scenarios that includes unconnected hazard vehicles. The coordination mechanisms of the proposed MARL include information sharing and cooperative policy learning, with Graph Convolutional Network (GCN)-Transformer as a spatial-temporal encoder that enhances the agent's environment awareness. The Safety Shield module with Control Barrier Functions (CBF)-based safety checking protects the agents from taking unsafe actions. We design a constrained multi-agent advantage actor-critic (CMAA2C) algorithm to train safe and cooperative policies for CAVs. With the experiment deployed in the CARLA simulator, we verify the performance of the safety checking, spatial-temporal encoder, and coordination mechanisms designed in our method by comparative experiments in several challenging scenarios with unconnected hazard vehicles. Results show that our proposed methodology significantly increases system safety and efficiency in challenging scenarios.

Deep learning is the method of choice for trajectory prediction for autonomous vehicles. Unfortunately, its data-hungry nature implicitly requires the availability of sufficiently rich and high-quality centralized datasets, which easily leads to privacy leakage. Besides, uncertainty-awareness becomes increasingly important for safety-crucial cyber physical systems whose prediction module heavily relies on machine learning tools. In this paper, we relax the data collection requirement and enhance uncertainty-awareness by using Federated Learning on Connected Autonomous Vehicles with an uncertainty-aware global objective. We name our algorithm as FLTP. We further introduce ALFLTP which boosts FLTP via using active learning techniques in adaptatively selecting participating clients. We consider two different metrics negative log-likelihood (NLL) and aleatoric uncertainty (AU) for client selection. Experiments on Argoverse dataset show that FLTP significantly outperforms the model trained on local data. In addition, ALFLTP-AU converges faster in training regression loss and performs better in terms of Miss Rate (MR) than FLTP in most rounds, and has more stable round-wise performance than ALFLTP-NLL.