摘要： 近年来，随着国民经济的飞速发展，在很多方面，原有的建设已经不能满足人们日益增长的需求，城市供水问题就是其中之一。近几年，随着城市人口的不断增长，城市规模也随之渐渐扩大，自然而然人们对城市建筑也有了新的要求，我国城市居民用水困难的问题也明显突出，原来的自来水管网的压力已经不能满足日常生活的需求，用水问题也给人们的日常生活带来极大的不方便。本文设计了一种自动恒压供水控制系统，其应具有24小时不间断供水、有数字显示供水高度、有必要的保护和报警、无水系统停止工作等功能，因此通过查阅相关文献资料，提出一种以AT89C51单片机为主控芯片，并结合变频器，报警单元，压力传感器等功能模块的控制系统，以此来实现自动恒压供水控制。此系统是以自来水管网的水压值为设定的参数，并且用控制变频器输出的频率值，使电机的转速能够自动的调节，并能依据用户用水量的多少，用单片机来控制水泵电机的数量以及控制变频器对其的调速，以此来实现水压的闭环调节，这就是恒压供水。
关键字：自动恒压；变频器；保护报警；压力传感器
Design of automatic constant-pressure water supply control system
Abstract：In recent years, with the rapid development of the national economy, in many ways, the original building has been unable to meet the growing demand, urban water supply problem is one of them. In recent years, as the urban population continues to grow, the scale of cities has gradually expanded, and people naturally also has a new requirement for urban architecture, urban residents in China water problems are visible, the original water pipe network pressure can no longer meet the needs of everyday life, water also brought great inconvenience to people’s daily lives. Paper design has a automatically constant pressure water control system, its should has 24 hours not continuous water, and has digital displayed water height, and has necessary of protection and alarm, and no water system stop work, function, so through check out related literature information, proposed a to AT89C51 single tablets machine mainly control chip, and combined frequency device, alarm unit, pressure sensor, function module of control system, to this to achieved automatically constant pressure water control. This system is to tap water tube network of hydraulic value for set of parameter, and with control frequency device output of frequency value, makes motor of speed can automatically of regulation, and can according to user water of how many, with single tablets machine to control pump motor of number and control frequency device on its of adjustable speed, to this to achieved hydraulic of closed ring regulation, this is constant pressure water.
Keywords：Automatic constant pressure ;converter ;protection alarm; pressure sensors
目录
第1章 前言……………………………………………………………………………………………….. 1
1.1本课题的研究目的和意义…………………………………………………………………. 1
1.2本课题的国内外研究现状…………………………………………………………………. 2
1.3本课题的设计内容及要求…………………………………………………………………. 3
第2章 总体方案设计…………………………………………………………………………………. 4
2.1方案论证………………………………………………………………………………………….. 4
2.2方案设计………………………………………………………………………………………….. 5
第3章 系统硬件设计…………………………………………………………………………………. 7
3.1单片机部分………………………………………………………………………………………. 7
3.1.1 AT89C51简介………………………………………………………………………… 7
3.1.2晶振电路………………………………………………………………………………… 9
3.1.3 复位电路……………………………………………………………………………… 10
3.2压力检测及变送电路………………………………………………………………………. 10
3.3 A/D模数转换电路…………………………………………………………………………… 11
3.4 D/A数模转换电路………………………………………………………………………….. 12
3.5电机控制电路…………………………………………………………………………………. 13
3.6无水检测电路…………………………………………………………………………………. 16
3.7显示电路………………………………………………………………………………………… 16
3.8键盘电路………………………………………………………………………………………… 18
3.9 报警电路……………………………………………………………………………………….. 18
3.10 串行通信接口电路……………………………………………………………………….. 18
第4章 控制算法设计……………………………………………………………………………….. 20
4.1 PID控制算法………………………………………………………………………………….. 20
第5章 系统软件设计…………………………………………………………………………………. 22
5.1 系统流程图……………………………………………………………………………………. 22
5.2 部分程序……………………………………………………………………………………….. 24
第6章 总结……………………………………………………………………………………………….. 31
致谢……………………………………………………………………………………………………………. 32
参考文献…………………………………………………………………………………………………….. 33
