基于PLC的中密度纤维板生产线智能监控系统的研究

【作者】 冯远静；

【导师】 杨青； 卢博友；

【作者基本信息】 西北农林科技大学 ， 机械设计与理论， 2001， 硕士

【摘要】 中密度纤维板是目前市场上主要的建材及装饰材料。目前我国共有100多条中密度纤维板生产线，但是普遍自动化水平不高，与国外同类生产线相比，无论从质量上还是效率上都存在很大的差距。本文的研究就是致力于提高国产中密度纤维板生产线的自动化水平和生产效率，提高中密度纤维板的质量。 首先，结合实际对MDF生产线的自动控制系统进行程序设计。并提供了大部分的梯形图。以生产率为目标，对生产线的热压工段装板机装板程序进行了改进。实际的应用表明，这种改进大大提高了生产线的生产效率。 在本研究中，首次将模糊控制理论应用于国内中密度纤维板生产线热压机的压力控制，为改善纤维板的质量进行了尝试。设计了模糊控制器和模糊控制软件，系统结果表明对热压机的压力进行良好的控制，跟原有的开关量控制相比，开关量控制的压力是等幅振荡过程，具有较大的最大动偏差。而模糊控制系统是较理想的衰减过程，能够把被控参数调节在设定值周围，参数的波动小，控制的品质好，具有良好的适应性。 论文通过剖析PLC面向生产的编程、控制、和通讯特点，运用实时系统的开发技术、面向对象的设计策略、直接操纵的界面风格，全面考虑到平台设计的可重用性、可扩展性的要求，注意突出人在应用系统中的地位和作用，提出了多台PLC实时监控软件平台的信息控制模式。利用现代计算机编程新技术—面向对象技术，采用Microsoft公司的开发工具Visual C++6.0，提出了基于Visual C++6.0的多台PLC的实时监控系统的框架思想，利用通信控件Microsoft Communication ControlVersion6.0，根据OMRON C200H PLC的专用通信协议，以OMRON C200H PLC为下位机，完成了中密度纤维板生产线监控系统的结构和程序模块设计。 文中还论述了多台PLC控制器与上位机之间实时通讯的机制及设计策略，多任务协调，消息的分组传递方式，系统前后台设计的相对独立性及协同工作的信息机制。 根据实际中的应用，自动控制系统的设计是稳定的。监控系统方便、灵活。对于提高中密度纤维板生产线的生产速度和中密度纤维板的质量有着重要的现实意义。更多还原

【Abstract】 Middle Density Fiberboard has been the main decorative product in the market. In our country, there are more than one hundred MDF product-lines, but most is in low automatic condition. The study of this paper is applied in the civil ones. In this paper, the automatic control system is designed based on the experience of on spot with programmable logic controller (PLC). The ladder program of the system is present in the paper. Some of the control program is modified to improve the efficient. Especial the programs in the mechanism which transform the board to presser. The use of the program in manufacturing indicates that it highly improved the speed of producing. In this paper, to improve the quality of fiberboard, fuzzy control theory is applied to the streamline in stress control of the center thermal presser. And designed the control software. The result shows the method applied here is right, controling the press in stable, which improves the quality of the fiberboard. Also in this paper, analyzing Production-Oriented program, control and communication of PLC, base on development technique of real-time operation system, Object-Oriented System Design, Direct Manipulation feature. We present the information control scheme of Multi-PLC Real-Time Control&Monitoring Platform, which emphasizes the reusability and expandability of software platform and human factor in application system instead of the monitoring in artificial. Based on the programming language visual C++6.O, used the ActiveX mscomm6.O, the system is developed according to the communicating protocol of PLC OMRON C200H Series produced by OMRON Corporation in Japan. Some strategies in the design of the software are discussed in detail: real-time communication scheme and strategy between multi-PLC and personal computer, coordination of multitask; group transmission of messages; relative separation and coordinate operation between user interface and application program; database design in the real-time system. According to the practice of automatic control program, the ladder program in PLC is stable. The real-time monitoring system is flexible.更多还原