基于PLC的扶梯变频系统设计_毕业设计.doc

基于PLC的扶梯变频系统设计 摘 要 自动扶梯是由一台特种结构型式的链式输送机和两台特殊结构型式的胶带输送机所组合而成的，用以在建筑物的不同层高间运载人员上下的一种连续输送机械。它的出现给人类的日常生活带来极大的便利，它同时也成为现代物质文明的一个重要标志。从第一台名义上的自动扶梯诞生以来，自动扶梯的发展迄今为止大约经历了100多年。 自动扶梯作为运送旅客的交通工具，不仅成功地缩小了目标间的距离，而且使超短途（如楼层、月台间等）的大流量人员运输成为可能。因此，经济学家说：“自动扶梯的出现使人们有了逛大型商场的欲望。”交通学家说“是自动扶梯和自动人行道的应用使我们可以把车站、机场建的尽可能大。”自动扶梯的应用已经改变了我们的生活。 随着自动扶梯进一步向着高科技、节能、智能化的方向发展，变频器在扶梯领域也被广泛地应用。该文系统采用子MM440变频器的控制组合，构成的调速系统对传统扶梯进行改造后，红外传感器、PLC可编程序控制器与西门使扶梯具备平稳启动、节能运行和检修运行功能。扶梯启动时，避免产生很大的启动电流；无人乘梯时，扶梯由额定运行速度转为低速运行，即节约了能源，减小了机械磨损，也为乘客明确了扶梯运行方向；扶梯检修时，检修运行功能保证了扶梯检修精度。 关键词：扶梯系统； PLC；MM440变频器 ABSTRACT Escalator is a combination of a special type of chain conveyor and two special types belt conveyor. And it is a continuous conveyor that use to carry staffs up and down between the different floors in a building. Its appearance brings human beings a great convenience in the daily life . It also become an important indicator of material. From the birth of the first escalator, the development of the escalator so far has gone through about 100 years.As a transport, escalator transport passengers, not only has succeeded in narrowing the distance between the target, but also make the ultra-short-haul(such as floors, platforms, etc.) and flow staff transport possible. Therefore, the economist said: The emergence of the escalator make people have the desire to go to shopping malls. Traffic experts said: The application of escalators and moving walkways make we can built the stations and the airports as large as possible. The application of the escalator has changed our lives.As the escalator toward further high-tech, energy-efficient, intelligent direction, the frequency converter has been widely used in escalator areas. The speed control system is a combination of infrared sensors, PLC and Siemens MM440 Inverter. After the transformation ,the traditional escalator provided with the functions ,such as a smooth start , energy-efficient operation and maintenance operation . When escalator starts, it avo