摘要

近年来，汽车行业的飞速发展使得我国的汽车保有量快速增长，但由此引发的交通事故导致的人员伤亡数量仍居高不下。从保护人身安全和降低交通事故发生的可能性的角度出发，车辆防碰撞系统能够使驾驶员在没注意到与前方车辆有碰撞危险的情况下采取自动紧急制动措施，避免与前车发生碰撞或者减缓与前车直接碰撞造成的危害，越来越受到大众的青睐。车辆防碰撞系统的关键技术是依靠其安装在车身前端的传感器来探测前方目标，精准的获取车辆前方目标的有效信息，并且能对前方目标的跟踪预测其下一步的运动状态然后采取相应的措施。随着人们对汽车安全性能要求的日益提高，对于车辆防碰撞系统的研究得到越来越多研究机构和汽车企业的重视。

为了解决汽车车辆防碰撞系统的信息传感、目标检测及识别跟踪问题，本文基于传感器融合算法，开展了如下工作：

首先，比较了适用于汽车车辆防碰撞系统中用来目标检测的传感器差别，本文选用雷达和视觉融合作为车辆防碰撞系统的传感器，详细介绍了毫米波雷达和视觉在车辆防碰撞系统中的主要功能。

并设计了一种基于毫米波雷达和视觉相机的车辆前方目标精确检测的方法，通过对毫米波雷达和视觉相机输出的目标进行数据预处理，使其能精确识别前方目标，并通过试验进行了验证。

其次，根据汽车行驶的特点，对汽车前方车辆的运动状态进行分析研究，并建立汽车前方车辆目标运动模型。比较几种目标运动模型的特点，然后选取合适的目标运动模型进行目标跟踪理论分析。针对车辆前方目标运动特点，在Simulink软件环境下搭建仿真模型，进行目标跟踪仿真对比试验。

最后，在保证雷达和摄像头安装精度的前提下，对基于毫米波雷达和视觉相机的车辆防碰撞系统搭建实车试验平台，使用基于当前统计模型卡尔曼滤波跟踪算法对车辆前方目标进行实车跟踪试验，结果表明，本文所采用的目标跟踪算法效果良好，能准确的对前方车辆进行跟踪。基于该目标算法进行了防碰撞试验，采用静止目标作为前方目标进行了实车试验，验证了车辆防碰撞系统及其算法的有效性。

关键词：车辆防碰撞；毫米波雷达；视觉相机；融合算法；仿真

Abstract

In recent years, the rapid development of the automobile industry has made the total number of vehicles in our country increase rapidly, but the number of casualties caused by traffic accidents is still high. From the perspective of protecting personal safety and reducing the possibility of traffic accidents, vehicle anti-collision system can enable drivers to take automatic emergency braking measures when they are unaware of the danger of collision with the vehicle in front, so as to avoid collision with the vehicle in front or mitigate the harm caused by direct collision with the vehicle in front, which is increasingly favored by the public. The key technology of vehicle anti-collision system relies on its sensor installed in the front of the body to detect the target in front of the vehicle, accurately obtain the effective information of the target in front of the vehicle, and can track the target in front of the next motion state and then take corresponding measures. With the increasing demand of automobile safety performance, more and more research institutions and automobile enterprises pay attention to the research of vehicle anti-collision system.

In order to solve the problem of information sensing, target detection, identification and tracking of vehicle anti-collision system, this paper carried out the following work based on sensor fusion algorithm:

Firstly, the difference of sensors used for target detection in vehicle anti-collision system is compared. In this paper, radar and vision fusion are selected as the sensors of vehicle anti-collision system, and the main functions of millimeter-wave radar and vision in vehicle anti-collision system are introduced in detail.

A precise detection method of vehicle forward target based on millimeter-wave radar and vision camera is designed. By preprocessing the data of the target output by millimeter-wave radar and vision camera, it can identify the target in front of the vehicle accurately, and it is verified by experiments.

Secondly, according to the driving characteristics of the vehicle, the motion state of the vehicle in front of the vehicle is analyzed and studied, and the target motion model of the vehicle in front of the vehicle is established. The characteristics of several target motion models are compared, and then the appropriate target motion model is selected for the theoretical analysis of target tracking. According to the characteristics of vehicle forward target movement, a simulation model was built under Simulink software environment, and the target tracking simulation and comparison test were carried out.

Keywords: Vehicle collision prevention; Millimeter wave radar; Visual camera; Fusion algorithm; simulation

目录

摘要............................................................................................................................. I

Abstract.................................................................................................................... II

第一章 绪论............................................................................................................. 1

1.1 研究课题背景........................................................................................... 1

1.2 国内外发展现状....................................................................................... 2

1.3 课题研究意义........................................................................................... 4

1.4 仿真工具MATLAB/Simulink简介........................................................ 4

1.5 课题的研究内容及章节安排.................................................................. 6

第二章 基于毫米波雷达的汽车防碰撞系统...................................................... 8

2.1 汽车防碰撞系统简介............................................................................... 8

2.2 毫米波雷达简介....................................................................................... 9

2.3 毫米波雷达结构及原理........................................................................... 9

第三章 基于视觉的汽车防碰撞系统................................................................. 12

3.1 车辆检测基础算法................................................................................. 12

3.1.1 HOG特征描述符......................................................................... 12

3.1.2 SVM算法原理............................................................................. 13

3.2 相关滤波算法......................................................................................... 15

第四章 目标识别及跟踪算法............................................................................. 17

4.1 前方目标跟踪原理................................................................................. 17

4.2 车辆检测跟踪算法框架........................................................................ 18

4.3 车辆检测的类型..................................................................................... 19

4.3.1 只包含检测算法的类型............................................................. 19

4.3.2 先检测后跟踪算法的类型......................................................... 19

4.4 常见的车辆检测算法............................................................................. 20

4.4.1 基于特征的方法......................................................................... 20

4.4.2 基于机器学习的方法................................................................. 21

4.4.3 基于光流的方法......................................................................... 21

4.4.4 基于模型的方法......................................................................... 22

4.5 常见的车辆跟踪算法............................................................................. 22

4.5.1 基于三维模型的方法................................................................. 22

4.52 基于 Kalman 滤波的方法......................................................... 23

第五章 基于MATLAB车辆防碰撞系统建模仿真设计................................ 24

5.1 车辆防碰撞系统的模型搭建................................................................ 24

5.1.1 车辆防碰撞系统控制器与传感器融合.................................... 25

5.1.2 车辆与环境搭建......................................................................... 27

5.2 车辆防碰撞系统的仿真分析................................................................ 28

5.3 本章小结.................................................................................................. 34

第六章 总结........................................................................................................... 35

参考文献................................................................................................................. 36

致    谢................................................................................................................. 38