摘要虽然国内外水位采集系统已有多种，但其系统并不完善。而且由于应用范围不同，需求和精度要求不一致，各个船闸水位采集系统并不能通用，与此同时，随着移动通信的普及，原有的简易的水位采集系统已不满足要求。因此，为了实时准确的监测水位，本文设计了一套由单片机控制的水位监测系统极短消息发送的硬件电路。47281

本文分析、比较了国内外船闸水位采集的各种方式的优缺点，根据精度、成本、地势等多方面需要，设计了本系统的整体方案，全面论述了系统的设计思想、硬件电路结构。具体分析了船闸水位自动采集及其短消息发送系统（硬件设计）的基本原理。根据系统的用途和性能要求，系统的信号采集部分采用差压式液位变送器，输出标准4~20mA直流电流，经过电平转换电路、滤波电路、D/A转换电路将上、下游水位的数字信号输入控制核心—AT89C51单片机中，一方面将处理过的数据通过LED显示出来，另一方面将数据通过RS485总线传输到PC机上，以便实时查阅与实时水位信息的短消息发送。通过短消息发送模块、GSM网络实现PC机与船之间进行的信息交流。

从系统的整体功能和要求出发，完成了系统的整体结构设计，并将电路划分为几个部分，逐一分析了各部分的功能和设计思想，最终实现了实时的船闸水位数据的LED显示，PC机显示，及水位信息的短消息发送。

毕业论文关键词：船闸；水位采集；硬件设计；单片机；短消息发送

Abstract

Though there are many kinds of water collection systems at home and abroad, these systems are not perfect. What's more since the application scope is different, the demand and the precision requirement is not consistent, the versatility of all the lock water collection system systems is very poor. At the same time, along with the popularization of mobile telecommunication, the original simple water collection system already can not meet the requirements. Therefore, in order to real-time monitor water level accurately, this article designed a set of hardware circuit about automatic acquisition of the ship lock water level and its short message sending system controlled by single-chip microcomputer.

This article analyses and compares the advantages and disadvantages of the ship lock water level collected at home and abroad in various ways. On the base of accuracy, cost, terrain, and many other needs it designs the overall program of this system, comprehensively discusses the system design idea, the hardware circuit structure. A detailed analysis of the basic principles of the automatic acquisition of the ship lock water level and its short message sending system (hardware design) is made. Based on the use and performance requirements of the system, the signal acquisition part of the system uses a different pressure level transmitter output standard 4 ~ 20mA DC current, after the level conversion circuit, filter circuit, the D / A conversion circuit, the downstream water level digital signal input the control core-AT89C51 microcontroller, on the one hand the data which has been processed will be displayed by LED,on the other hand the data bus transfers to the PC through the RS485, so that real-time consult and the real-time short message sending water level information are convenient . By the short message sending module, GSM network achieves information exchange between the PC and the ship.

Considering its overall function and requirement,the whole structure design of the system has been completed. Circuit has been pided into several parts , the function and design thought of each part were analyzed, and finally achieve the real-time data of lock's water level displaying by  LED , PC , and short news sending of water level information.

Keywords: Ship lock; Water level collection ; Hardware design; microcontroller; Short message sending system