A Survey on Platoon-Based Vehicular Cyber-Physical Systems

Vehicles on the road with some common interests can cooperatively form a platoon-based driving pattern, in which a vehicle follows another vehicle and maintains a small and nearly constant distance to the preceding vehicle. It has been proved that, compared with driving individually, such a platoon-based driving pattern can significantly improve road capacity and energy efficiency. Moreover, with the emerging vehicular ad hoc network (VANET), the performance of a platoon in terms of road capacity, safety, energy efficiency, etc., can be further improved. On the other hand, the physical dynamics of vehicles inside the platoon can also affect the performance of a VANET. Such a complex system can be considered a platoon-based vehicular cyber-physical system (VCPS), which has attracted significant attention recently. In this paper, we present a comprehensive survey on a platoon-based VCPS. We first review the related work of a platoon-based VCPS. We then introduce two elementary techniques involved in a platoon-based VCPS, i.e., the vehicular networking architecture and standards, and traffic dynamics, respectively. We further discuss the fundamental issues in a platoon-based VCPS, including vehicle platooning/clustering, cooperative adaptive cruise control, platoon-based vehicular communications, etc., all of which are characterized by the tightly coupled relationship between traffic dynamics and VANET behaviors. Since system verification is critical to VCPS development, we also give an overview of VCPS simulation tools. Finally, we share our view on some open issues that may lead to new research directions.

I. Introduction

WITH the development of automobile industry and urbanization, more and more vehicles are on the highway linking adjacent cities. It is estimated that currently there are more than 1 billion registered motor vehicles worldwide, and that the number will be doubled within the next 10 to 20 years. As a result, a series of critical issues are becoming more serious in modern transportation systems, such as traffic

In this paper, “traffic” is limited to the context of vehicle transportation.

congestion, traffic accidents, energy waste, and pollution. For instance, in the USA along, traffic congestion costs drivers more than $100 billion annually due to wasted fuel and lost time [1]. Moreover, vehicle emissions caused by traffic congestion are also regarded as the key contribution to air pollution and are a major ingredient in the creation of haze in some large cities.