基于MCGS的液位控制系统设计.doc

目录第1章系统总体方案选择·································5 第2章系统结构框图与工作原理·························7 系统机构框图···········································7 工作原理···············································8 第3章各单元软硬件······································9 模拟控制对象系统······································9 控制台·················································9 上位机及控制软件系统·································9 模拟量输入模块 ICP-7017 ······························ 10 模拟量输出模块 ICP-7024 ······························ 11 电动调节阀············································ 11 液位传感器············································ 12 第4章软件设计与说明··································13 用户窗口··············································13 实时数据库············································16 第5章系统调试··········································17 设备连接··············································17 系统调试··············································17 调试结果·············································· 18 注意事项··············································19 第6章总结················································ 20 附录程序清单············································· 21 第1章系统总体方案选择随着工业生产的迅速发展,工艺条件越来越复杂。对过程控制的要求越来越高。过程控制系统的设计是以被控过程的特性为依据的。由于工业过程的复杂、多变,因此其特性多半属多变量、分布参数、大惯性、大滞后和非线性等等。为了满足上述特点与工艺要求,过程控制中的控制方法是十分丰富的。通常有单变量控制系统,也有多变量控制系统,有复杂控制系统,也有满足特定要求控制系统。在工业生产过程中,液体贮槽设备如进料罐、成品罐、中间缓冲容器、水箱等应用十分普遍,为保证生产正常进行,物料进出需均衡,以保证过程的物料平衡,因此工艺要求贮槽内的液位需维持在某个给定值上下,或在某一小范围内变化,并保证物料不产生溢出,要求设计一个液位控制系统。对分析设计的要求,生产工艺比较简单要求并不高,所以采用单回路控制系统进行设计。单回路控制系统又称简单控制系统, 是指由一个被控系统、一个检测元件及变送器、一个调节器和一个执行器所构成的闭合系统。单回路控制系统是最简单、最基本、最成熟的一种控制方式。单回路控制系统根据被控量的系统、液位单回路控制系统等。单回路控制系统的结构比较简单,所需的自动化装置数量少, 操作维护也比较方便,因此在化工自动化中使用很普遍,这类系统占控制回路的绝大多数。单回路控制系统虽然简单,但它的分析、设计方法是其它各种复杂过程控制系统分析、设计的基础。对单回路控制系统进行分析,设计,调试处理的方法,理解单回路控制系统对各个环节的影响,就可以分析处理好更复杂的设计问题。这里选择的是液位单回路控制系统。图 1-1 是一个单回路反馈控制系统单回路控制系统方框图的一般形式如下: 图 1-1 单回路反馈控制系统_ 调节器调节阀被控过 Wm(S) X(S) Y(S) F(S) Z(S) _第2章系统结构框图与工作原理 系统结构框图将模拟过程控制系统中的控制器的功能用计算机来实现,就组成了一个典型的基于计算机的控制系统,