摘要:随着社会的发展，时代的进步，车慢慢得到了普及，导致在一些公共场合造成停车困难，车辆拥挤，倒车时既要前瞻，又要后看。所以研制汽车后部探测障碍物的倒车雷达便成为近些年来的重点研究对象。为此，本文根据声波在空气中传播反射原理，以超声波换能器为接口部件，基于STC89C52单片机的超声波测距器（由超声波发射模块、信号接收模块、单片机处理模块、LCD显示以及声音报警模块组成），设计了以单片机为核心，利用超声波实现无接触测距的倒车雷达系统。详细介绍了测距器的硬件组成、检测原理、方法以及软件结构。

关键词：超声波；单片机；倒车测距

ABSTRACT:With the development of society, progress of the times, has slowly been popular, resulting in some public parking difficulties, vehicle congestion, backing up both forward and look after. Development of automobile parking sensor will detect obstacles by the Department in recent years to focus on objects. Therefore, this article according to the Sonic transmission-reflection in the air, ultrasonic transducer for the interface parts, ultrasonic range finder based on the STC89C52 microcontroller (ultrasonic transmitter and receiver module, single-chip signal processing modules, LCD display and audible alarm module), design a microcontroller as the core, implementation of non-contact distance measurement with ultrasonic parking sensor system. Detailed Finder composition, theory, methods of detection of hardware and software structure.

Key words：Ultrasonic wave ;Single-chip Microcomputer ;reverse range

　　　本文所设计的倒车雷达系统是保证汽车安全的辅助系统。通过超声波探头反射超声波，使用高速单片机计算测量车与障碍物之间的往返时间然后再计算出车与障碍物的距离，并加入了软件补偿，提高了距离计算的精度，然后显示在LCD显示屏上，当在探测的范围有障碍物时，蜂鸣器提示报警，当距离小于最小安全距离时，蜂鸣器不间断报警。实际测试证明该系统工作稳定，能够满足一般近距离测距要求，且成本低、有良好的性价比.