To ensure safe cooperative driving in mixed traffic with both manned and unmanned vehicles, it is crucial to understand and model the driving styles of human drivers. This paper explores how to develop accurate recognition of driving style and use that for the prediction of vehicle motion, which enables better performance in cooperative driving. A simulation testbed that consists of a driving simulator and a copilot is first introduced for the purpose of data collection and testing. A Long Short-Term Memory (LSTM)-based network that models human driving styles and predicts driving acceleration is developed. Standalone tests are conducted to examine the model performance in the simulation testbed. Finally, the model is evaluated in a series of merging experiments that involves 5 vehicles.

Autonomous vehicles are gradually entering the transportation system. The traffic will become more heterogeneous since both autonomous and human-driven vehicles will share the roads. Cooperative driving, by promoting synchronized actions and shared situational awareness among vehicles, can significantly enhance driving safety. On the other hand, understanding human drivers is a pivotal step for cooperative driving in such mixed traffic environments, which facilitates effective interaction between human drivers and their vehicles. This paper presents a testbed that can be used to conduct research in intelligent and cooperative driving. The testbed consists of driving simulators, custom-designed copilots with an Artificial Intelligence engine, an optimization server, and a cloud database. The copilot is capable of sensing and understanding the human driver, the vehicle and the traffic. It can assist the driver by providing timely alerts on potential risks. Most importantly, it can communicate with other nearby vehicles for cooperative driving. Two case studies are presented to validate and evaluate the testbed. The first case study demonstrates the performance of the copilot in human distraction detection and driving assistance. The second case study focuses on cooperative driving between one human-driven vehicle and two connected autonomous vehicles in a lane-changing scenario. We expect this research testbed to be used in various research projects that involve human-driven vehicles and connected autonomous vehicles.

To achieve safe cooperative driving in mixed traffic of manned and unmanned vehicles, it is necessary to understand and model human drivers' driving behaviors. This paper proposed a Hidden Markov Model (HMM)-based method to analyze human driver's control and vehicle's dynamics; and then recognize the human driver's action, such as accelerating, braking, and changing lanes. With the knowledge of the human driver's actions, a probability model is used to predict the human-driven vehicle's acceleration. Such information on the driver behavior and the vehicle behavior can be used to achieve safer cooperative driving, which is realized using vehicle-to-vehicle (V2V) communication and model predictive control (MPC). The proposed method was tested and evaluated in our custom-built cooperative driving testbed. Experimental results show that the above driver action model is effective and accurate. A preliminary case study on a lane merging scenario is provided to further validate its effectiveness and capability.

Modeling a human-driven vehicle is a difficult subject since human drivers have a variety of stochastic behavioral components that influence their driving styles. We develop a cooperative driving framework to incorporate dif-ferent human behavior aspects, including the attentiveness of a driver and the tendency of the driver following advising commands. To demonstrate the framework, we consider the merging coordination between a human-driven vehicle and an autonomous vehicle (AV) in a connected environment. We propose a stochastic model predictive controller (sMPC) to address the stochasticity in human driving behavior and design coordinated merging actions to optimize the AV input and influence human driving behavior through advising commands. Simulation and human-in-the-loop (HITL) experimental results show that our formulation is capable of accommodating a distracted driver and optimizing AV inputs based on human driving behavior recognition.

This paper presents a cooperative driving testbed based on vehicle-to-vehicle (V2V) communication, which can be used for research in intelligent transportation systems, such as collision avoidance in mixed traffic of both human-driven vehicles and autonomous vehicles. To achieve the goal, an intelligent copilot is developed. The copilot can share the data regarding vehicle status, intention, etc, with other nearby vehicles through V2V communication. Several case studies are conducted to validate the proposed testbed and evaluate the performances of cooperative driving. When dangerous situations occur, the copilot solves the collision avoidance problem using Mixed Integer Programming (MIP), which either provides control commands to the autonomous vehicle, or advises the human driver to take action. Experimental results show that the safety and stability of the involved vehicles have been significantly enhanced. This cooperative driving testbed can be used by researchers to develop and test cooperative driving algorithms before they are deployed in real vehicles.