【作者】 黄永达；

【导师】 吴铁军；

【作者基本信息】 浙江大学 ， 控制科学与工程， 2001， 硕士

【摘要】 城市尘活和工业废水处理一直是环境保护领域的一个重要的课题。但是目前还没有一个合适的仪器仪表能对废水的一些重要工业指标，如BOD、COD等作实时的监测，因此对废水处理实施自动控制的难度是非常大的。在这种情况下，很多废水处理厂的生产都是利用生产人员的经验来控制的，自动化水平很低，其直接后果就是出水水质无法保证和能源的巨大消耗。 本文提出的软测量仪表，利用软测量原理，根据一些易测变量(温度、溶解氧浓度、PH值、浊度等)和BOD、COD等难测变量之间的数学关系(软测量模型)，通过测量易测变量和数学计算得到难测变量，从而实现对难测变量的测量。 本文的主要介绍了软测量仪表较完整的设计开发工作： 第一章：介绍软测量技术在工业上运用的意义和实现软测量技术的可行性，软测量技术的应用场合、数学模型的建立和校正这三个要素，软测量仪表的现状。和软测量技术对过程检测和控制系统的影响。 第二章：根据本软测量仪表的实际运用要求给出的总体结构，同时也给出对各部分电气的具体要求。 第三章：介绍数码管显示仪表、CRT显示仪表和LCD显示仪表；以及有关键盘的特性和方式，同时确定所采用的显示媒体和键盘的方式，并在此基础上对软测量仪表的人机交互画面作出规划。 第四章：介绍三类仪表常采用的A／D转换类型和与此相关的一些A／D转换芯片，并最终确定使用V／F转换为本仪表的测量数据输入方式。 第五章：介绍和对比了三类仪表常采用的通信方式：20mA电流环，RS-232和RS-485通信标准，并最终确定采用RS-485通信方式。 第六章：对目前6类存储器的有关特性和存取方式作了个介绍，对比了两类下载程序的执行方式，以及对算法的可靠性进行了设计。更多还原

【Abstract】 Treatment of the waste water from city life and industry is always an important problem in protection of environment. At present time, there isn’t any instrument can measure some important parameters of the waste water, such as BOD. COD. in real-time. So it’s very difficult to use auto-control techniques in the w^aste water treatment industry. In this condition, most waste water treatment factory control their production by workers’ experiences, so the quality of the treated water is hard to be guaranteed and wasting of the resources is another disadvantage.In this thesis, we present a programmed instrument. By using the program, it establishes a mathematic relation between some parameters measured easily (such as temperature, concentration of dissolved oxygen. PH) and the parameters measured hard we need. By measuring those parameters easily measured and calculation, we can get the results of parameters we need almost in real-time. In this thesis, we introduce the design of this instrument:In chapter one, we introduce some background knowledge, including the Soft-Sensing Technique, the situation of the Soft-Sensing instruments model nowadays, and how this instrument will play its’ role in so many instruments.In chapter two, we give an integrant design of the Online Softsensoring Instrument. Also a design suggestion is given for each part.I n chapter three, we introduce three kinds of instruments, and we decide to design the instrument with LCD - liquid crystal displayer. Later a mainly interface of the instrument is given.In chapter four, we introduce some methods of A/D conversion, and we take V/F as our A/D conversion.In chapter five, we introduce some knowledge of standard communication protocols, and we finally take the RS-485 mode.In chapter six. we introduce six types of memory, two running ways of the download program, and which is our choice. Later we also discussed security the download program and the security of the main program.更多还原