LANZHOU UNIVERSITY OF TECHNOLOGY
毕业设计
题 目 蔬菜大棚温湿度控制系统的PLC程序设计
学生姓名 学 号 专业班级 指导教师
学 院 电信学院 答辩日期 2012年6月12日
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兰州理工大学毕业设计
摘 要
温室大棚对现在的人们来说，是非常熟悉的一个名词，因为现在我们生活中的很多花卉、蔬菜、水果都是从温室大棚中种植出来的。如何利用自动检测与自动控制系统有效的控制好温室大棚内的各种环境因子，以提高温室大棚环境的控制精度和效果，对我国温室业的发展有着不可估量的重要意义。 本设计采用西门子S7-300系列可编程控制器来实现自动化控制的温室大棚。温度、湿度等环境因子在植物过程中起重要作用，在检测这环境因子的时候考虑到精度，反应速度，方便设备连接等问题，将采用温度传感器，湿度传感器对环境各项指标进行检测，传感器将检测的结果送入PLC中，由PLC将其与设定值进行比较，再发出相应的指令驱动电机﹑卷帘等设备运行或停止来调节室内的温度、湿度，从而达到智能化，自动化控制的目的。使用step7及wincc flexible实现上下位连调，详细的介绍系统的特点，组成，硬件设计及软件设计等问题。
关键词：蔬菜大棚；PLC；温湿度控制
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兰州理工大学毕业设计
Abstract
Greenhouse for the people now is a very familiar noun, because now we live in a lot of flowers, vegetables, fruit which from greenhouse shelter of planting out. How to use automatic detection and automatic control system of effective control of greenhouse trellis inside, in order to improve the environmental factor trellis environment control precision of the greenhouse effect and has become the greenhouse industry research in China at present. This design USES the Siemens s7-300 PLC to realize the automation control greenhouse trellis. Temperature, humidity environment factors in the process of plants plays an important role in detecting the environmental factor, when considering the accuracy, the reaction speed, convenient device connected by such issues, will the temperature sensor,humidity sensors detect the indicators of environment, the sensor will test results by PLC sent PLC compare it with setting, then sends out the corresponding order-driven heating element,, the fan, ventilation window, filling light equipment, sunshade shade equipment operation or stop to adjust indoor temperature, light, humidity, so as to achieve the purpose of intelligent, automation control. Discuss PLC control system application in plants greenhouse canopy, Use the step7 and wincc flexible to achieve the upper and lower sandhi detailed introduces the characteristics of the system, the composition, the hardware design and software design.
Keywords: Vegetables greenhouse；PLC system；Temperature and humidity control
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兰州理工大学毕业设计
目录
摘 要 .................................................................................................................................. I Abstract ............................................................................................................................. II 第一章 绪 论 ................................................................................................................... 1
1.1 课题背景及研究意义 ...................................................................................... 1 1.2国内外温室控制技术发展概况 ......................................................................... 2 1.3 选题的目的和意义 ............................................................................................ 3 第二章 系统的整体设计方案 ......................................................................................... 4
2.1系统的设计任务 ................................................................................................. 4 2.2 控制系统核心部件的选择 ................................................................................ 4
2.2.1 通讯方式简介 ......................................................................................... 4 2.2.2 温室控制系统硬件配置 ......................................................................... 5 2.3．控制方案 .......................................................................................................... 6 2.4.系统工作原理 ..................................................................................................... 7 第三章 硬件系统的研究与设计 ................................................................................. 8
3.1 PLC的选型 ...................................................................................................... 8
3.1.1 I/O地址分配 ......................................................................................... 9 3.1.2 接线图 ................................................................................................... 11 3.2 传感器的选型 .................................................................................................. 12
3.2.1温度传感器 ............................................................................................ 12 3.2.3 空气湿度传感器 ................................................................................... 14 3.3 电磁阀的选型 .................................................................................................. 14 3.4低压控制器件选型 ........................................................................................... 15 3.5主回路及控制回路的设计 ............................................................................... 21
3.5.1 系统主电路设计 ................................................................................... 21 3.5.2 控制回路设计 ....................................................................................... 22 3.6 就地控制箱设计 .............................................................................................. 24 第四章、软件系统的研究与设计 ................................................................................. 25
4.1 STEP7软件编程简介 ....................................................................................... 25
4.1.1 软件简介 ............................................................................................. 25 4.1.2软件运行 ................................................................................................ 27
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兰州理工大学毕业设计
4.1.3 主要功能块简介 ................................................................................... 28 4.2系统流程图 ....................................................................................................... 29
4.2.1 主程序流程图 ....................................................................................... 29 4.2.2 温度子程序 ........................................................................................... 29 4.2.3 湿度子程序 ........................................................................................... 30 4.2.4 故障报警子程序 ................................................................................... 32
第五章 控制系统监控界面设计 ................................................................................... 34
5.1 上位软件 .......................................................................................................... 34 5.2 通讯连接 .......................................................................................................... 34 5.3 人机界面 .......................................................................................................... 35 结 论 ............................................................................................................................... 37 致谢 ................................................................................................................................. 38 参考文献 ......................................................................................................................... 39 外文翻译 ......................................................................................................................... 40 附录一：程序梯形图 ..................................................................................................... 59
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