基于plc的四层电梯完美论文..doc

摘要 随着科学技术的发展、近年来，我国的电梯生产技术得到了迅速发展．一些电梯厂也在不断改进设计、修改工艺。更新换代生产更新型的电梯，电梯主要分为机械系统与控制系统两大部份，随着自动控制理论与微电子技术的发展，电梯的拖动方式与控制手段均发生了很大的变化，交流调速是当前电梯拖动的主要发展方向。目前电梯控制系统主要有三种控制方式：继电路控制系统(“早期安装的电梯多位继电器控制系统)、PLC控制系统、微机控制系统。继电器控制系统由于故障率高、可靠性差、控制方式不灵活以及消耗功率大等缺点，目前已逐渐被淘汰。微机控制系统虽在智能控制方面有较强的功能，但也存在抗干扰性差，系统设计复杂，一般维修人员难以掌握其维修技术等缺陷。而PLC控制系统由于运行可靠性高，使用维修方便，抗干扰性强,设计和调试周期较短等优点，倍受人们重视等优点，已成为目前在电梯控制系统中使用最多的控制方式，目前也广泛用于传统继电器控制系统的技术改造。 本系统软件的编制主要是根据其实现的功能进行了梯形图的设计，包括开关门、内外指令的处理、选层定向、顺向截梯等。 该系统具有先进、可靠、经济的特色。该电梯控制系统具有自动运行、指层、厅召唤、选层、选向等功能，具有集选控制的特点。 关键词：电梯 PLC 可编程控制器 Abstract With the development of science and technology, in recent years, Chinas elevator production technology have developed rapidly. Some elevator design successfully also has a great improvement in design and process changes. Update production more new elevators, elevator mainly divides into mechanical system and control system with two most, automatic control theory and microelectronics technology development, the elevator drag with control method all way has changed very greatly, ac adjustable speed is the main development direction of elevator drag. At present the elevator control system is mainly have three kinds of control ways: following the circuit control system ( early installation of elevator more relay control system), PLC control system, the microcomputer control system. Relay control system due to high failure rate, the method of control, poor reliability and not flexible and disadvantages such as big power consumption, has gradually been eliminated. Though the microcomputer control system in intelligent control has the strong function, but also exists perturbation resistance is poor, system design complex, general maintenance personnel hard to grasp its maintenance technology etc. And PLC control system defects due to run high reliability, convenient operation and maintenance, strong anti-interference, design and commissioning period shorter, more people to pay attention to such advantages as etc, and has