前馈控制系统、反馈控制系统.doc

摘要
可编程序控制器(PLC)是一种集自动化技术、计算机技术和通信技术为一体的高可靠性的工业计算机,应用很广泛,现在已经越来越成熟,小批量、多品种、多规格、低成本和高质量的产品不断涌入市场。本设计主要是在西门子编程软件S7-300的基础上实现PLC的前馈反馈系统的设计,并通过具体的实例,即对加热炉温度的前馈反馈控制的实现来说明前馈反馈的具体流程。加热炉内的实时温度经过温度传感器、温度变送器将模拟量传送给PLC的模拟量输入模块,模拟量输入模块将模拟量转换成数字量送到PLC内部处理,再由模拟量输出模块将数字量转换为模拟量输出控制阀门的开度以达到炉内温度稳定的控制。对现场的前馈-反馈控制系统进行控制的,如何将前馈-反馈控制系统得到的数据经过PLC后传送到上位机,进行实时监控。经仿真运行后,本系统能实现控制要求。
关键字:前馈-反馈控制;可编程控制器; ;加热炉
Abstract
Programmable Logic Controller (PLC) is a set of automation technology, computer technology munication technology as one of the high reliability puter,and PLC is widely used. Now it is more and more mature,smaller quantities, more kinds ,lower cost and higher quality in the market. This design is abased on the programming software of Siemens to implement PLC-based feedforward-feedback control system. This design introduces an example to explain the procedure of feedforward-feedback system. The example is that through temperature control in heating furnace which is used feedforward and feedback control system. Real-time temperature, inside the furnace, after the temperature sensors, temperature transmitters discovered will be sent to the analog input module of PLC. Analog input modules convert analog to digital, and sent the digital data to CPU of PLC to process. Then analog output modules convert digital to analog to control valve, so the system achieves a stable furnace temperature control. Focus of this study is about that how to use PLC and to control feedforward-feedback system of on-scene, and how to make feedforward-feedback system convey the date puter via PLC, then, using configuration software implement real-time monitoring.
Keywords:feedforward-feedback;Programmable Logic Controller; ;heating furnace
目录
1 绪论 1
国内外研究现状 1
本课题研究内容及方法 2
2 基于 PLC的双闭环流量比值控制系统设计 3
系统的工艺流程 3
控制系统的硬件选型 4
PLC的发展及特点 4
PLC的内部结构 5
西门子公司的S7系列PLC 7
CPU的选型 8
I/O模块的选型 8
电源模块的选型 9
系统各部分硬件选型 9
温度传感器的选择 10
温度变送器的选择 10