Spacing Policies for Adaptive Cruise Control: A Survey

Cunxue Wu,Zhongming Xu,Kuining Li,Yang Liu,Minghui Hu,Chunyun Fu

doi:10.1109/access.2020.2978244

Abstract

Adaptive cruise control (ACC) systems are designed to provide longitudinal assistance for drivers to enhance safety and reduce workload. As the core of all ACC control algorithms, the spacing policy plays a crucial role in various aspects. This paper presents a comprehensive survey on spacing policies for existing ACC solutions in the literature. The objectives of this paper are to clarify the operating mechanisms and characteristics of the common spacing policies, and to reveal their advantages and shortcomings by means of a comparative study. In this survey, the general evaluation criteria for spacing policies are first introduced. Then, the existing spacing policies are categorized into different types according to their operating mechanisms, and their characteristics are carefully reviewed and explained. A comparative study is followed to analyze the performances of five typical spacing policies in the literature, including the constant spacing policy, constant time headway, traffic flow stability, constant safety factor and human driving behavior spacing policies. The contents provided in this paper serve as a tool for understanding current ACC spacing policies, and pave the way for future ACC enhancement.

Highlights

In recent decades, advanced driver assistance systems (ADAS) have attracted significant attention from both academia and automotive industry [1]
The individual vehicle stability is a basic requirement [32], which guarantees the fundamental functions of an adaptive cruise control (ACC) system
SUMMARY As an important type of ADAS, the ACC systems have been extensively studied by academia and are currently available in a wide range of passenger vehicles on the market

Summary

Introduction

In recent decades, advanced driver assistance systems (ADAS) have attracted significant attention from both academia and automotive industry [1]. As a typical type of ADAS, the adaptive cruise control (ACC) systems assist with driving in one of the most important aspects – vehicle longitudinal control [2]. ACC is an extension or enhancement of the traditional cruise control (CC) systems [3], [4]. The first generation ACC systems were mainly developed for improving driving comfort [7], [8]. ACC systems have the potential to improve other performance such as traffic efficiency, safety, fuel economy and emission [9]–[14].

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Results

Conclusion