基于PLC的搅拌机控制系统的设计

滨州学院本科毕业设计（论文）

i 基于PLC的搅拌机控制系统的设计

摘 要

液体搅拌已成为现代工厂中必不可少的环节，以往的搅拌机都是由继电器控制的，其系统较为复杂，响应速度缓慢。基于PLC控制技术的飞速发展，用软件就可以取代继电器系统中的触点和接线，因此，选用PLC对搅拌机的控制系统进行设计。

本设计主要采用PLC控制技术实现对液体搅拌系统的自动控制。首先设计系统的工艺流程，根据工艺流程进行硬件配置，主要包括PLC、电动机、电磁阀、泵、液位变送器等元件的选型。然后对控制系统的主电路、控制电路进行设计，从而达到控制要求。最后根据控制要求进行软件设计，通过液位变送器将采集到的现场液位高度传送给PLC，并由PLC对现场数据逻辑处理后，发出相应的控制指令，完成系统的自动控制。该设计在保证其功能的前提下，对其结构进行了尽量的简化，从而达到降低制造成本和维护成本的目的。

关键字：PLC, 液体搅拌，控制系统，自动控制

滨州学院本科毕业设计（论文）

ii The design of the Mixer Control System based on PLC

Abstract

Liquid mixing has become an indispensable part of the modern

factories, past mixer is controlled by relay, the system is more complicated,

the speed of response is slow. Based on the rapid development of PLC

control technology, using the software can replace the contact and

connection in relay system, therefore, this article chooses PLC to design the

control system of mixer.

This design mainly uses the PLC control technology to realize

automatic control of liquid mixing system. Firstly, designing process of the

system which can determine the hardware configuration , mainly including

PLC, motor, solenoid valve, pump, liquid level transmitter components

selection, etc. Then so as to achieve the requirements of the control,

designing the control system of main circuit, control circuit. At last,

according to the control requirements for software design, through the liquid

level transmitter will be collected the water height transmitted to PLC, and

after processing by PLC to field data logic, a corresponding control

instruction, complete the automatic control system. The design under the

premise of function, try to achieve aim of lowering costs manufacturing and

maintenance, thereby simplify the structure of system.

Keywords: PLC, Liquid mixing, Control system, automatic control滨州学院本科毕业设计（论文）

I 目 录

第一章 绪论 ....................................................................................................................... 1

1.1 设计背景 ...................................................................................................................... 1

1.2 研究目的与意义 .......................................................................................................... 2

第二章 搅拌机控制系统总体方案设计 ........................................................................... 3

2.1 控制系统的简介 .......................................................................................................... 3

2.1.1 控制方式的确定 ....................................................................................................... 3

2.1.2 控制系统的优点 ....................................................................................................... 4

2.1.3 控制系统的组成 ....................................................................................................... 4

2.2 系统设计内容及需求分析 .......................................................................................... 5

2.2.1 系统设计内容 ........................................................................................................... 5

2.2.2 系统需求分析 ........................................................................................................... 6

2.3 系统设计的基本步骤 .................................................................................................. 6

第三章 控制系统的硬件设计 ........................................................................................... 7

3.1 系统的工艺流程设计 .................................................................................................. 7

3.2 PLC的工作原理 ........................................................................................................... 7

3.3 硬件模块的设计 .......................................................................................................... 9

3.3.1 可编程控制器的选用 ............................................................................................... 9

3.3.2 液位变送器的选用 ................................................................................................. 12

3.3.3 电磁阀的选用 ......................................................................................................... 13

3.4 系统主电路的设计 .................................................................................................... 14

3.5 系统控制回路的设计 ................................................................................................ 16

第四章 系统的软件设计 ................................................................................................. 17

4.1 程序设计思想 ............................................................................................................ 17

4.2 系统初始化程序及主程序设计 ................................................................................ 17

4.3 报警电路程序的设计 ................................................................................................ 18