【作者】 何志刚；

【导师】 阮鸿雁；

【作者基本信息】 江苏大学 ， 机械电子工程， 2005， 硕士

【摘要】 现场总线技术具有数字化、全分散性、开放性和互操作性等特点,代表了今后工业控制网络发展的方向,是当前自动控制领域中倍受关注的技术之一。本文根据城市污水处理厂的实际案例,分析并设计了基于现场总线技术的城市污水处理自动控制系统。 本文首先在理论上对现场总线控制系统进行了全面的探讨和阐述,介绍了现场总线的概念、网络结构、通信模型以及五种典型的现场总线,并且尤为深入的对PROFIBUS现场总线进行了阐述。然后根据污水处理厂实际应用的需要,从综合自动化控制系统的完整性、可靠性、开放性及可扩充性几个方面,比较分析了DCS、现场总线、工业以太网等工业应用网络的连接方式,提出了基于PROFIBUS现场总线网络的通信方案。并且依据城市污水处理工艺实例给出了污水处理过程自动控制系统的总体设计方案和具体实施细节。 另外,城市污水处理过程工艺复杂,具有连续生产、参数检测困难、非线性、间歇性、大滞后、干扰多等特点。本文针对污水处理过程中的污水曝气过程进行了控制策略的研究,并且通过用MATLAB软件仿真,比较了传统PID控制法和模糊控制法的运行结果。由于模糊控制策略控制效果较好,而且不需要控制对象的精确数学模型,本文选用了简单易行的查控制表方法在PLC上实现模糊控制策略。 在文章的最后,本文对现场总线技术在工业控制领域的应用前景作了展望。更多还原

【Abstract】 Field bus technology is a digital, distributed, open and inter-operational technology, which represents the development trend of industrial control system. It is one of the technology what has attracted more attention in the field of automatic control. In this paper, according to the factual case of city sewage treatment plant, we analyzed and designed an automatic control system for swage treatment what is based on field bus technology.At first, in this paper, we detailed discussed the field bus control system in theory, introduced the concept of field bus, the structure of network, communication model and five representative field bus. We emphasized on the detail of PROFIBUS field bus. And then, consider the actual control requirement in a sewage work, this paper compares and analyzes several industry network patterns such as DCS, field bus, industrial Ethernet in a integrated automatic system’s integrality, reliability, extendibility and open capability, and brings forward a communication network scheme, which is based on PROFIBUS field bus. According to the city swage treatment process, we put forward the integrated plan and execution particular for the swage treatment automatic control system.In addition, there are many difficulties in the process of swage treatment, such as continuous working, the variable is hard to be online measured, non-linearity, intermittence, delay and more disturbers. In this paper we research into the process of aeration tank control. We compare the results of respectively applying PID and fuzzy strategy using of MATLAB emulation toolbox. The fuzzy strategy gets a good result, and it needn’t a correct math model, so it is chose and implemented in PLC through a table look-up program.Lastly, this paper prospected the foreground of field bus in the industry control field.更多还原