Impact of Cooperative Adaptive Cruise Control on Traffic Stability

Abstract

Cooperative adaptive cruise control (CACC) is one of the popular connected and automated vehicle (CAV) applications for cooperative driving automation with combined connectivity and automation technologies to improve string stability. This study aimed to derive the string stability conditions of a CACC controller and analyze the impacts of CACC on string stability for both a fleet of homogeneous CAVs and for heterogeneous traffic with human-driven vehicles (HDVs), connected vehicles (CVs) with connectivity technologies only, and autonomous vehicles (AVs) with automation technologies only. We mathematically analyzed the impact of CACC on string stability for both homogeneous and heterogeneous traffic flow. We adopted parameters from literature for HDVs, CVs, and AVs for the heterogeneous traffic case. We found there was a minimum constant time headway required for each parameter design to ensure stability in homogeneous CACC traffic. In addition, the constant time headway and the length of control time interval had positive correlation with stability, but the control parameter had a negative correlation with stability. The numerical analysis also showed that CACC vehicles could maintain string stability better than CVs and AVs under low HDV market penetration rates for the mixed traffic case.

Research on a Cooperative Adaptive Cruise Control (CACC) Algorithm Based on Frenet Frame with Lateral and Longitudinal Directions

“…In recent years, the research on CACC mainly focuses on longitudinal single-lane control, including stability analysis [ 30 , 31 , 32 , 33 , 34 ], communication problem analysis [ 35 , 36 , 37 , 38 ], heterogeneous problem analysis [ 39 , 40 , 41 , 42 ], etc. The control algorithm is mainly aimed at improving the original single-vehicle control algorithm, such as PID control, sliding mode control, and distributed model predictive control.…”

Connected Automated and Human-Driven Vehicle Mixed Traffic in Urban Freeway Interchanges: Safety Analysis and Design Assumptions

“…Studies have shown that human drivers in CAV platoons adjust their maneuvers, frequently decreasing their time headways [10,11]. Nevertheless, scenarios characterized by diminished reaction times of human drivers may lead to collisions [12].…”

Multianticipative Adaptive Cruise Control Compared With Connectivity-Enhanced Solutions: Simulation-Based Investigation in Mixed Traffic Platoons

“…This phenomenon is well known for its criticality and there is considerable ongoing research aimed at finding possible solutions to address the concern. A common belief is that such a shortcoming can only be addressed by allowing vehicles to communicate with each other, thus anticipating the onboard perception system reaction time ( 9 , 10 ). Such connectivity-enhanced solutions are commonly known as cooperative ACC (CACC) and rely on either vehicle-to-vehicle (V2V) or vehicle-to-infrastructure (V2I) wireless communication technologies.…”

“…Such connectivity-enhanced solutions are commonly known as cooperative ACC (CACC) and rely on either vehicle-to-vehicle (V2V) or vehicle-to-infrastructure (V2I) wireless communication technologies. CACC has been studied in several works both via microscopic simulation ( 9 , 11–13 ) and real-world campaigns ( 14 , 15 ). However, despite the huge potential behind the technology, real-world market adoption is largely undermined by cybersecurity threats, lack of infrastructure, and data privacy ( 16 , 17 ) and data ownership ( 18 ) concerns, which makes the theoretical benefit not attainable in the foreseeable future.…”