《超声波液位探测系统的研究》_精品.doc

摘 要 液位检测技术在现代化工业生产中应用十分广泛，在气象水位的测量、大型油罐液位的测量等。随着智能仪器概念的提出。在电子和微控制芯片发展的基础上，液位仪器也经历着日新月异的变化。 本论文介绍了一种由AT89C51单片机为主控元件的超声波液位测量系统。文中给出了系统的硬件设计各个功能机器原理图，同时给出软件系统程序设计方法，系统实现了标准液位的检测及显示功能。 超声波液位测量仪应用超声回波原理技术，在硬件部分，超声波发射电路将AT89C51单片机控制的每隔20ms的方波脉冲信号放大到-300V，以满足超声波发射探头的发射需要。超声波接收电路对接收的回波进行发大整形，送回单片机。系统以AT89C51单片机为设计核心，测量得到超声波的传播时间，计算出传播的距离，从而得到所要测量的液位距离,并通过LED显示出来。软件部分，设计了中断程序、显示程序、主程序等。使得程序部分适合硬件部分，使系统功能得以实现。 关键词：超声波；AT89C51；液位测量 Abstract The technique of fluid level detect is extremely widespread in modern industrial production, for example: the measurement of meteorological water level，giant oil pot fluid level, and so on. Along with the advanced intelligent instrument conception, on the basis of development the electronic and the micro control chip, the fluid level instrument is taking on daily variations. The thesis introduces an ultrasonic wave liquid measuring system that uses AT89C51 as major controlling components, and gives the principle of hardware designing of the system, and the programming method, which achieves the measure and displaying the liquid level. The ultrasonic wave liquid meter applies the technique of ultrasonic wave back principle, in hardware, and the emission circuit controlled by 89C51 output -300v pulse every 20ms,and expiates the probe to output the signal of ultrasonic wave at 1MHZ. Electric circuit of Ultrasonic wave to receive enlarges and waves echo of received, returns to 89C51. The return signal is received by the probe of the ultrasonic wave, reads the value in the the interrupt produce, then figure out the height of the liquid by the single chip micro-computer and display it through the LED. Software part designs interrupt routine, display sequence, master routine and so on. Let program division suits hardware part, and to realize enables the system function. Key words: ultrasonic wave; AT89C51; liquid depth measure 目 录 摘 要 I Abstract II 1 绪论 1 1.1液位测量综述 1 1.2液位计的分类 2 1.2.1按照原理分类 2 1.2.2按照接触方式分类 6 1.3超声波液位计的优缺点与可行性 8 1.4课题的主要