Cooperative Handling of Cut-Ins and Emergency Braking for Connected Automated Vehicles with Heterogeneous Powertrains

The widespread adoption of Connected Auto-mated Vehicles (CAVs) is highly dependent on their ability to handle real-world traffic conditions, including cut-in/cut-out maneuvers and emergency braking scenarios. This paper presents a Cooperative Adaptive Cruise Control (CACC) frame-work enhanced with motion planning and control strategies to robustly manage these challenges in mixed traffic environments with heterogeneous powertrains and dynamics. The proposed control architecture builds upon previous CACC research by incorporating real-time trajectory planning for cut-in vehicles, dynamic time-gap adjustments, and coordinated emergency braking maneuvers. A hierarchical control structure is implemented, with low-level controllers ensuring accurate longitudinal tracking across different vehicle types, and a high-level motion planner handling dynamic interactions within the vehicle string. The system is validated through real-world experiments on test tracks, where vehicles with diverse power-train configurations (internal combustion engine, hybrid, and electric) execute CACC with dynamic gap management. The results demonstrate that the proposed approach enhances vehicle string stability, minimizes disturbance amplification, and ensures safe cut-in/cut-out transitions while maintaining reasonable time-gap policies. Additionally, coordinated emergency braking across heterogeneous vehicles is evaluated, revealing significant improvements in response time, braking consistency, and collision risk reduction. These findings demonstrate the practicality of CACC deployment in heterogeneous traffic, improving both safety and robustness in dynamic real-world environments.