四层电梯PLC控制系统设计.doc

目录
前言······················································2
系统设计要求及方案··································3
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系统设计方案选择·····································4
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PLC控制电梯的优点································5
PLC简介·····································
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PLC的产生···········································6
可编程控制器的定义···································7
PLC的特点···········································8
PLC控制系统总体设计································8
电梯PLC控制的基本结构设计··························8
系统结构框图·········································9
程序设计逻辑流程图···································9
I/O口分配···········································10
实际程序············································10
设计总结··················································13
参考文献··················································14
前言
电梯作为高层建筑不可缺少的运输工具,其使用越来越广泛,电梯控制系统主要用以下三种控制方法:继电器控制系统,PLC控制系统和微机控制系统,继电器控制系统故障率高,控制方法不灵活及功率消耗大等缺点,目前已经逐渐被淘汰。微机控制系统虽然在控制方面有比较强大的功能,但也存在一定的不足之处,例如抗干扰性差,系统设计比较复杂,一般维修人员难以掌握其维修技术,这些都限制了微机控制系统应用的广泛性。而PLC控制系统由于运行可靠,使用维修方便,抗干扰性能强等优越性,成为目前在电梯控制系统中使用最多的控制方法。尤其在2008年奥运会和2010年世博会以及亚运会在中国的举办,将有力的带动电梯革命的节能环保化发展,电梯产业的前景和走势也随着社会的需求悄然发生着变化。市场对新一代的绿色电梯,节能电梯和智能电梯的需求越来越旺盛。从而有效的推动了PLC技术在电梯控制领域的应用。电梯需要运行平稳且舒适性好,使用变频器进行变频控制电机的速度能达到很好的控制目的,现在的电梯通常是PLC+变频器组成的控制系统。在此次课程设计中,电梯的使用功能都是通过控制软件来实现的,为了使控制软件和电梯的运行动作有较好的对应关系,电梯的软件控制程序,我主要分为楼层的显示程序、呼叫信号程序、上下行程序、开关门程序,各司其职,对电梯的运行进行控制。
第一章系统设计要求及方案

课程题目
四层电梯PLC控制系统设计
设计内容
设计四层电梯控制系统的硬件电路(主电路硬件接线设计和PLC外部连线图)和软件程序;
PLC程序编制与调试;
四层电梯PLC控制系统的综合调试,电梯模型如右图所示;
撰写课程设计报告;
完成课程设计答辩。
四层电梯控制系统的设计要求:
1)基本功能:
电梯应包括各楼层外呼梯开关,其中1层只有向上开关;4层只有向下开关;中间层(2、3层)具有上、下各两个开关。
不论轿厢停在何处,均能根据召唤信号自动判断电梯运行方向,然