摘 要

超声波雷达又叫倒车雷达，是现在汽车的基本配置。本文设计的倒车系统是基于STC单片机的汽车倒车雷达控制系统。该系统可以减少新老司机在倒车困难，避免在倒车时因为看不见后方障碍物而发生碰撞。本系统主要的原理是超声波测距原理。系统的主要由五个模块组成：单片机控制模块，超声波测距模块，温度补偿模块，显示模块，报警模块。主要的工作流程：使用STC89C52单片机对所有的传感器进行数据收集处理，首先是由HC-SR04超声波传感器可以得出超声波的传播时间，通过DS18B20温度传感器得出当时环境下的温度，超声波速度通过温度补偿校正后乘上时间除以二得到距离。在比较四个超声波测的距离后，把最小距离显示在LCD12864液晶显示屏上，若显示的距离达到设定的距离后，蜂鸣器发出不同频率的警报声提醒司机。本次设计的倒车雷达成本低，使用方便，简单可控。

关键词：超声波测距；倒车雷达；单片机；模块化

Design of Vehicle Parking Radar Control System Based on STC MCU

ABSTRACT

Ultrasound radar, also known as reversing radar, it is the basic configuration of automobiles. The reversing system designed that the reversing radar control system based on STC MCU in this paper. The system can reduce the difficulty of reversing the old and new drivers and avoid collisions when the vehicle is reversed because the rear obstacles are not visible. The main principle of this system is the principle of ultrasonic ranging. The system mainly consists of five modules: MCU control module, ultrasonic ranging module, temperature compensation module, display module and alarm module. The main working processes: the STC89C52 MUC is collections and processes of all sensors’ data. The propagation time of ultrasound can be detected by HC-SR04 ultrasonic sensor. Through the DS18B20 temperature sensor, we can get the temperature of the environment at that time. Ultrasound velocity is corrected by temperature compensation and multiplied by time divided by two to obtain distance. After comparing four ultrasonic ranging distances, the minimum distance is displayed on LCD 12864 LCD screen. After comparing four ultrasonic ranging distances, the minimum distance is displayed on LCD12864 liquid crystal display. If the display distance reaches the preset distance. The buzzer sends out alarms at different frequencies to alert drivers. The reversing radar designed in this paper is low cost, easy to use, simple and controllable.

Key words：Ultrasonic ranging; reversing radar; single chip microcomputer; modular

目 录

第一章 绪论………………………………………………………………………………………………1

1.1引言……..........................................................................................................................................1

1.1.1本课题研究的背景…….......................................................................................................1

1.1.2本课题研究目的和意义.......................................................................................................1

1.1.3 倒车雷达的发展状况..........................................................................................................2

1.1.4 倒车雷达的应用状况..........................................................................................................3

1.2本论文主要内容及各章节安排......................................................................................................4

第二章 超声波测距的原理…………………………………………………………................................6

2.1 超声波的基本概念……………………………………………………………...........................6

2.1.1超声波概述…………………………………………………...............................................6

2.1.2超声波的基本特点...............................................................................................................6

2.1.3超声波的传播速度...............................................................................................................6

2.1.4超声波在空气传播中的衰减...............................................................................................7

2.2 超声波传感器的基本特性……………………………………………………….........................8

2.2.1压电式传感器的工作原理………………………………………………….......................8

第三章 系统的整体设计方案………………………........……………………………………...............10

3.1轿车盲区介绍……………………………………………………………….........................10

3.2 倒车雷达控制方案的选择……………………………………………………………........10

3.3整体方案参数的选取……………………………………………….....................................11

3.3.1超声波传感器安装的位置............................................................................................12

3.3.2超声波传感器脉冲个数的选择....................................................................................12

3.3.3超声波传感器数量的选择............................................................................................13

3.4各硬件型号的选择.................................................................................................................14第四章 硬件的设计...................................................................................................................................17

4.1硬件设计模块...................................................................................................................................17