机械自动化专业毕业论文--基于PLC的水塔水位控制系统设计.docVIP

摘 要 水位控制ABSTRACT In the industrial and agricultural production process, often need to measure and control thewater level.?Water level control applications in everyday life are very wide, such as water towers, groundwater, hydropower and other water level control case.?But with the growing world population, it is the increase in water, relay towers used in the past, the water level automatic control system operation due to the frequent cause mechanical wear, convenient maintenance and updating can no longer meet the actual needs of the people, the paper used?Siemens PLC S7-200 programmable controller as a series of small water tower water level automatic control system core, the water level of the tower the functions of automatic control system of the requirement analysis.?Main achieved is through the actual water level sensor detects the water tower, specific information will be transmitted to the water level control module consisting of PLC, the A / D conversion, to compare data, to control the pumping action of the motor, while data reduction, the indicated level?specific information, if the water level lower or higher than a set value, we will send the hazard warning signal.?In this paper, a water tank level control system design process, the water tower level control system based on PLC design a good implementation of the specific process.?KEY WORDS: Water level control, Siemens S7-200, The sensor目 录 摘 要 I ABSTRACT I 第1章 引 言 1 第2章 可编程器简介 2 2.1可编程控制器的产生 2 2.2 PLC的发展 4 2.3 PLC的基本结构 5 2.3.1 中央处理单元(CPU) 5 2.3.2 存储器 6 2.3.3 输入/输出模块 7 2.3.4 扩展模块 8 2.3.5 编程器 8 2.4 PLC的基本工作原理 8 2.5 PLC的主要应用 9 2.6 S7-200系列PLC元件功能 10 第3章 水塔水位控制系统方案设计 13 3.1 传统水塔水位控制 13 3.1.1 工作原理 13 3.1.2 外部接线与控制列表 13 3.1.3程序编辑及分析 15 3.2 PID水塔水位控制系统的工作原理 15 3.2.1 设计分析 15 3.2.2 可行性试验 16 3.2.3 可行性分析 17 3.3 水位闭环控制系统 17 第4章 PLC中PID控制器的实现 19 4.1 PID算法 19 4.2 PID应用 20 4.3 PLC实现PID控制的方式 20 4.4 PLC PID控制器的实现 21 4.5 PID指令及回路表 23 第5章　系统硬件开发设计 24 5.1 可编程控制器的选型 24 5.2 EM235模拟量模块 25 5.2.1 EM235的