George Gunter, Roman Lysecky, Maria Laura Delle Monache, Derek Gloudemans, Daniel B. Work, Jonathan Sprinkle, Benedetto Piccoli, Rahul Bhadani, Sean T. McQuade, Matt Bunting, Raphael Stern, Benjamin Seibold, Department of Civil and Environmental Engineering [Urbana], University of Illinois at Urbana-Champaign [Urbana], University of Illinois System-University of Illinois System, Institute for Software Integrated Systems [Nashville], Vanderbilt University [Nashville], Department of Civil and Environmental Engineering [Nashville], Department of Mathematical Sciences [Camden], Rutgers University [Camden], Rutgers University System (Rutgers)-Rutgers University System (Rutgers), Department of Electrical and Computer Engineering [Tucson] (ECE), University of Arizona, Dynamics and Control of Networks (DANCE), Inria Grenoble - Rhône-Alpes, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-GIPSA Pôle Automatique et Diagnostic (GIPSA-PAD), Grenoble Images Parole Signal Automatique (GIPSA-lab), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA)-Grenoble Images Parole Signal Automatique (GIPSA-lab), Université Grenoble Alpes (UGA), Department of Computer Science & Engineering [Riverside] (CSE), University of California [Riverside] (UCR), University of California-University of California, Temple University [Philadelphia], Pennsylvania Commonwealth System of Higher Education (PCSHE), Department of Electrical and Computer Engineering [Tuscon], Inria Associate Team MEMENTO, University of California [Riverside] (UC Riverside), and University of California (UC)-University of California (UC)
International audience; In this article, we assess the string stability of seven 2018 model year adaptive cruise control (ACC) equipped vehicles that are widely available in the US market. Seven distinct vehicle models from two different vehicle makes are analyzed using data collected from more than 1,200 miles of driving in car-following experiments with ACC engaged by the follower vehicle. The resulting dataset is used to identify the parameters of a linear second order delay differential equation model that approximates the behavior of the black box ACC systems. The string stability of the data-fitted model associated with each vehicle is assessed, and the main finding is that all seven vehicle models have string unstable ACC systems. For one commonly available vehicle model that offers ACC as a standard feature on all trim levels, we validate the string stability finding with a multi-vehicle platoon experiment in which all vehicles are the same year, make, and model. In this test, an initial disturbance of 6 mph is amplified to a 25 mph disturbance, at which point the last vehicle in the platoon is observed to disengage the ACC. The data collected in the driving experiments is made available, representing the largest publicly available comparative driving dataset on ACC equipped vehicles.