摘 要
为了实施有效的温室环境控制,把工业上比较成熟的、先进的控制手段引入到农业的生产中。我国对于现代化大型温室的研制已经进入了一个新的阶段。如何利用自动控制系统有效的控制温室室内环境,并进行高效的作物栽培管理,是目前温室研究的重要课题之一,对于提高我国温室制造业的水平有着重大的意义。
针对当前我国温室科技含量低、生产水平落后、现代化的智能温室几乎全部依赖进口的局面,本课题采用先进的计算机技术、微处理器控制技术和智能传感数据采集技术设计出农业温室大棚温湿度远程监控系统。本系统由一台PC机与多个下位机控制器组成主从式分布结构,下位机采用性价比高的单片机,主要实现对温室环境参数的数据采集和控制工作。上位机采用PC机,主要用于对多个农业大棚环境参数数据的管理和对参数的设置工作。系统采用半双工式RS-485总线型通信网络进行数据传输。利用VB6.0面向对象编程技术开发出了交互的友好人机界面。通过实时读取和历史存储农业大棚内环境参数值,实现了对温度、湿度等环境参数的管理,方便查阅。
实验研究表明:本系统具有一定的测控精度,系统根据作物生长的需要,实现了温室内温度、湿度两种重要环境因子变化的自动监测,为作物速生、优质、高产提供了良好的生长条件。本系统操作方便,界面良好,为用户提供了温室内的各种环境因子实时变化情况,并且可通过修改环境控制参数,实现了真正意义的在线干预温室运行的目的。本系统还具有运行可靠,性价比高,便于升级扩充等特点。
关键词:农业大棚;温湿度;RS-485;VB6.0
Abstract
In order to control the environment effectively,many mature and advanced methods should be applied in the control—system of greenhouse.Now how to use automatic control system to contr01 the environment effectively and how to manage crop growth effectively,are two important tasks in greenhouse research.It has much significance to improve the level of greenhouse manufacturing.
Now greenhouse of our country is low in scientific and technological content,the level of production is laggard,me modernized intellectual greenhouse nearly all rely on the import,this topic adopts advanced computer technology,micro.Electronic control technology and sensor to design the remote monitor and control system of the greenhouse computer,this system makes up of one personal computer and a 10t of controllers,which make up a principal and subordinate distributed structure.The slave machine adopts the single chip which has a high performance,and realize the collection of the environmental parameters of the greenhouse and the system contr01.The master machine makes up of a personal computer which is used to control environmental parameters and set environmental parameters.The system adopts RS-485 bus in communication network.The communication is half duplex.Using accumulate and cheek—up algorithm.Utilizing VB6.0 to face object database programming technology.We use a friendly man-machine interface.By reading and storing the real—time and environmental parameters’value in the greenhouse,the management to tow greenhouse environmental parameters such as temperature,humidity are realized.We Can check the history data conveniently.
Research shows:this system has certain precision of monitor and contr01.According to the need that the crop grows,this system has realized the automatic control on tow environmental factors(temperature,humidiry)in the greenhouse.And this system has offered a good growth condition for the crop that call grows rapidly,high-quality and high—yield.This System is easy to operate:the interface is friendly,offering the real—time environmental factors in the greenhouse.By revasmg environmental control parameters,this system realizes the operation online.This system also have these characteristic: run reliably,high performance,improve easily etc.
Key words:Agricultural greenhouses;Temperature and humidity;RS-485;VB6.0
目 录
第1章 绪 论 4
1.1 引言 4
1.2 国内外研究现状、趋势及难点 5
1.2.1 农业温室大棚的研究现状 5
1.2.2 农业温室大棚研究的发展趋势 6
1.2.3 农业温室大棚智能化发展存在的难点 8
第2章 系统的整体设计方案 10
2.1 本文研究的目的及内容 10
2.2 系统整体结构图 10
2.3 各部分电路介绍 11
第3章 下位机子系统的设计 13
3.1 单片机最小系统 13
3.1.1 控制器的选择 13
3.1.2 复位电路 17
3.1.3 时钟电路 19
3.1.4 单片机最小系统电路图 20
3.2 温湿度检测电路 20
3.2.1 传感器 20
3.2.2 SHT75与单片机的接口电路 22
3.3 报警电路 22
3.3.1 74HC595 23
3.3.2 报警电路图 24
3.4 下位机通信接口 24
3.4.1 总线标准 24
3.4.2 MAX485 25
3.4.3 下位机通信接口电路图 26
3.5 下位机程序设计 26
3.5.1 温湿度检测程序 26
3.5.2 通信程序设计 27
第4章 上位机通信接口及软件设计 29
4.1 通信接口硬件电路的设计 29
4.1.1 MAX232 29
4.1.2 通信接口电路 30
4.1.3 通信协议 31
4.1.4 通信接口转换卡软件设计 32
4.2 上位机监控软件设计 33
4.2.1 PC机监控界面的设计 33
第5章 总 结 37
参考文献 38
致 谢 39
附 录Ⅰ 原理图 40
附 录Ⅱ 程序 41