Hardware-In-The-Loop Testing of Connected and Automated Vehicle Applications: A Use Case For Cooperative Adaptive Cruise Control

Most existing studies on connected and automated vehicle (CAV) applications apply simulation to evaluate system effectiveness. Model accuracy, limited data for calibration, and simulation assumptions limit the validity of evaluation results. One alternative approach is to use emerging hardware-in-the-loop (HIL) testing methods that allow physical test vehicles to interact with virtual vehicles from traffic simulation models. This provides an evaluation environment that can replicate deployment conditions at early stages of CAV implementation - without incurring excessive costs related to large field tests. In this study, a hardware-in-the-loop (HIL) testing system for CAV applications is proposed. Cooperative adaptive cruise control (CACC) is one of the key CAV applications that has received a lot of attention. This study develops a HIL proof-of-concept testing prototype for CAV applications in a vehicle-to-vehicle (V2V) environment. The contributions of this study include developing a HIL testing architecture for V2V-based CAV applications; implementing the proposed HIL architecture; developing a prototype; and testing CACC as the selected use case to observe HIL system performance. The results of this effort also contribute to a better understanding of CACC string performance.