基于超声波的料位计的检测系统的设计.doc

摘 要 本文介绍了基于超声波的固体生料料位的检测系统，该系统结构简单、性能可靠，安装方便、测量精度较高，电路实现容易，工作稳定可靠。弥补了传统测量方法存在的问题。设计由单片机控制超声波的轮流发射，并且通过单片机的记录和读取发射超声波和接收到回波的时间差，进而计算出测量的距离。本文介绍了超声测距的基本原理，对超声传感器的结构及频率特性进行了分析。实现了以空气中超声波的传播速度为确定条件，利用漫反射原理，发射器发出超声脉冲，到达物料位置后反射回来由接收器接收，根据声波往返时间，在已知声速的条件下计算出物料的距离。并对影响测距精度的主要参数进行了讨论，为实现大距离的测量提供可靠依据。在超声测距原理的基础上，设计出系统的总体构成。根据固体生料料位测量的特点，通过四大模块构建系统，即发射模块、接收放大模块、单片机控制模块和LED显示模块。为了保证测量精度，还采用数字温度传感器DS1820实现温度的补偿。系统是在硬件和软件配合运用下实现距离的测量。在软件方面根据系统测量的方法和要求，对系统进行了程序设计。由触发信号的产生到中断信号的接收由完成一次数据的采集通过数据处理到数据的显示，都在软件的编程下实现。 关键词：超声波；测距；料位；单片机；温度传感器 ABSTRACT This article introduces the sodil crudematerial position detecting system based on the ultrasonic wave.The structure of system is simple, and its performance is reliable. The system is also provided with convenient installation, high measure accuracy. It is easy to realize the electric circuit which has no use for debugging, and its work state is stable and reliable.The system controls ultrasonic launch in turn by Single Chip Microcomputer,the time difference of launching ultrasonic wave and receiving the echo by Chip Microcomputer records, then calculates the survey distance. In this article we introduce the basic principle of supersonic measure distance,and analyze the structure and frequency characteristic of supersonic sensor. The system takes the supersonic propagation velocity in the air as the determinate condition and make use of diffuse reflection principle. The launcher sends out the supersonic pulse reflected and received by receiver after arriving the material position .According to the round-trip time of sound wave, it can calculate the material distance on condition that sonic speed is known. In this paper some main parameters of measure system have also been discussed,further provide the reliable gist for measring great distance. The system overall constitution has been put forward on the principle of supersonic measure distance.According to the characteristic of the cement crude material position, we have designed four big