基于51单片机的超声波测距系统大学毕业（设计）论文.doc

本科生毕业论文 超声波测距系统的设计 毕业论文诚信声明 本人郑重声明： 所呈交的毕业论文《 超声波测距系统的设计 年 月 日 摘 要 超声波是指频率在20kHz以上的声波，它属于机械波。超声波也遵循一般机械波在弹性介质中的传播规律，如在介质的分界面处发生反射和折射现象，在进入介质后被介质吸收而发生衰减等。正是因为具有这些性质，使得超声波可以用于距离的测量中。随着科技水平的不断提高，超声波测距技术被广泛应用于人们日常工作和生活之中。 系统的设计主要包括两部分，即硬件电路和软件程序。硬件电路主要包括发射电路、接收电路、单片机电路、电源电路和显示电路，另外还有LCD控制电路和复位电路等。我采用以AT89S5单片机为核心的低成本、高精度、微型化数字显示超声波测距仪的硬件电路。超声波测距超声波测距Is the frequency at 20kHz ultrasonic sound waves above , it is a mechanical wave . Also follow the general mechanical ultrasonic wave propagation in elastic media , such as reflection and refraction at the interface media into the media after the decay occurs , such as dielectric absorption . It is because of these properties , so that ultrasound can be used to measure the distance . With increasing levels of technology , ultrasonic ranging technology is widely used among peoples daily work and life.Design of the system consists of two parts , namely hardware and software programs. The hardware circuit includes a transmitter circuit, a receiver circuit, the microcontroller circuit, a power supply circuit and a display circuit , in addition to the LCD control circuit and a reset circuit. I used to AT89S51 core, low-cost, high-precision, miniaturized ultrasonic rangefinder digital display hardware circuits. The entire circuit is modular in design , the signal transmission and reception , power , temperature measurement and display module. Signal amplification and detection probe launch after launch out MCU timer is started , the original way back after the ultrasound was launched , after amplification bandpass filtering plastic and other sectors, then the microcontroller receives the counter to stop working and get the time . After the temperature measurement to the microcontroller, the speed through the process of correcting a combination of both to achieve Ultrasonic Ranging function. Software program from the main program , launch subrout