摘 要
在傳統(tǒng)的DCS控制系統(tǒng)中,模擬信號(hào)的傳輸均采用一對(duì)一的連接方式,因而整個(gè)系統(tǒng)的結(jié)構(gòu)十分龐雜,成本高。而且抗干擾能力低,故障率高。近幾年,隨著計(jì)算機(jī)及網(wǎng)絡(luò)技術(shù)的發(fā)展,現(xiàn)場總線控制系統(tǒng)FCS(Fieldbus Control System)在工業(yè)各領(lǐng)域中得到廣泛的應(yīng)用。
本文以目前國際上廣受關(guān)注的CAN總線為基礎(chǔ),設(shè)計(jì)了基于CAN總線的紙漿濃度智能測控系統(tǒng)的設(shè)計(jì)。以改進(jìn)傳統(tǒng)DCS控制系統(tǒng)的不足,改善紙漿濃度測控中測控的性能。本系統(tǒng)具有結(jié)構(gòu)簡單,控制精度高,抗干擾能力強(qiáng),性價(jià)比高,有突出的可靠性,實(shí)時(shí)性和靈活性等優(yōu)點(diǎn)。
論文首先對(duì)現(xiàn)場總線做了初步簡介,簡單介紹了目前國際上主流的現(xiàn)場總線,并詳細(xì)介紹了CAN總線的性能特點(diǎn)。然后簡單闡述了造紙的基本工藝,濃度控制機(jī)理以及目前濃度測控系統(tǒng)技術(shù)發(fā)展的現(xiàn)狀。接著對(duì)控制方案進(jìn)行了分析,并與傳統(tǒng)的DCS控制系統(tǒng)進(jìn)行了比較。然后討論了下位智能測控節(jié)點(diǎn)和上位機(jī)的設(shè)計(jì),并對(duì)各模塊電路以及軟件進(jìn)行設(shè)計(jì),列出了部分系統(tǒng)軟件程序框圖以及SJA1000初始化程序、發(fā)送程序和接收程序。之后論文對(duì)控制算法進(jìn)行了設(shè)計(jì),并對(duì)PID參數(shù)進(jìn)行了整定。
關(guān)鍵詞:CAN總線 紙漿濃度測控 測控節(jié)點(diǎn) AT89C55
Abstract
In the traditional DCS controlling system, the transmission of analog signals always adopts an one to one connecting manner, therefore, the structure of the whole system is quite huge and complicated, with high cost. Moreover, its capacity of resisting disturbance is quite low and the fault rate is quite high. In recent years, as the development of computer and Network technology, Field bus Control System is being widely used in the various industrious fields. This paper bases on the CAN Bus which draws wide attention internationally recently, studying the design of the paper pulp measuring and controlling system, in order to improve the weak points of traditional DCS controlling system and controlling capability in paper pulp measuring and controlling. This system has many advantages, such as simple structure, high controlling precision, strong capability of resisting disturbance, high cost performance, outstanding reliability, instantaneity, flexibility and so on.
This paper firstly offers an brief introduction of Profibus, stating the mainstream Profibus in the world and introducing the capability and characters of CAN Bus in detail. Then it expatiates the basic paper making craft, the mechanism of thickness controlling and the technological developing status of recent thickness controlling system. After that, it analyzes the controlling schemes and compares them with the traditional DCS controlling system. Finally it discusses the design of spot Intelligent Measurement and Control nodes and designs all kinds of modular circuit and software,Listing the framework of part system software procedure and initializing, senging, reciving procedure of the SJA1000.Then this paper sets the parameters of PID algorithm.
Key word:CAN field bus;Paper Pulp Thickness Measuring and Controlling;Measuring and Controlling node;AT89C55