Virtual Vehicle Flocking Control for Multi-Lane Ramp Merging

This paper presents a novel approach to ramp merging in multi-lane highway scenarios for connected and automated vehicles (CAVs) using virtual vehicle flocking control. Unlike existing methods that mainly focus on single-lane scenarios through virtual platooning, the proposed approach aims to address the complicated multi-lane merging scenarios by allowing main road vehicles to execute lane changes, create space for merging vehicles, and balance traffic flow across lanes. The new vehicle flocking control design can virtually project and manage CAVs on the ramp and main road as a coordinated group. Three key components are considered in the virtual vehicle flocking design for ramp merging: 1) Optimal selection of lane-changing vehicles on the main road to minimize flocking transitions using a Wasserstein distance-based indicator; 2) Smooth lane-change navigation to reach target lanes by adjusting the navigation effect of flocking control inputs; 3) Avoidance of unnecessary accelerations and decelerations through a heterogeneous connection approach for smoother merging. The simulation results of ramp merging on a three-lane highway demonstrate the effectiveness of the proposed method. Compared to traditional virtual platooning strategies based on an intelligent driver model, the improved merging efficiency and safety are verified.