The Optimal Control Algorithm of Connected and Automated Vehicles at Roundabouts with Communication Delay

TL;DR

This paper develops a control algorithm for connected and automated vehicles at roundabouts that accounts for communication delays, improving safety and efficiency in complex traffic scenarios through a novel distributed model predictive control approach.

Contribution

It introduces a new roundabout control algorithm that considers communication delays and vehicle interaction uncertainties, enhancing safety and traffic flow in CAV environments.

Findings

The proposed algorithm effectively manages vehicle flow at roundabouts under communication delays.

Simulation results show improved safety and reduced travel time compared to existing methods.

The control strategy adapts well to different traffic densities and penetration rates.

Abstract

Connected and automated vehicles (CAVs) rely on wireless communication to exchange state information for distributed control, making communication delays a critical factor that can affect vehicle motion and degrade control performance, particularly in high-speed scenarios. To address these challenges in the complex environment of roundabout intersections, this paper proposes a roundabout control algorithm, which takes into account the uncertainty of interactive information caused by time delays. First, to maintain the required distance between the current vehicle and its preceding and following vehicles, conflicting vehicles are identified based on the time-to-collision (TTC) in the conflict zone. To fully consider communication performance, a vehicle motion model incorporating time delays is established. According to the distributed model predictive control (DMPC) mechanism, the vehicle motion control that satisfies the roundabout constraints is determined. Second, by scheduling the sequence of vehicles entering the roundabout, a multiscale optimization objective is developed by integrating vehicle motion indicators and roundabout system indicators. Traffic density and travel time are embedded into the optimization problem to guide vehicles to enter the roundabout safely and stably. Through a variety of simulation experiments, the effectiveness of the proposed control algorithm is verified by comparing its performance with that of multiple control algorithms under different autonomous vehicle penetration rates and heavy traffic load scenarios.