基于分層策略與模糊五級(jí)SDG的故障定位方法
發(fā)布時(shí)間：2018-07-13 16:41
【摘要】：隨著科學(xué)技術(shù)的不斷進(jìn)步，化工過(guò)程的復(fù)雜性不斷提升，向著大規(guī)模、自動(dòng)化的趨勢(shì)發(fā)展。化工生產(chǎn)的原料易燃易爆，生產(chǎn)環(huán)境一般處于極端條件，因此故障會(huì)造成很大的危害。如何快速高效地推理并確定故障源已經(jīng)成為了化工安全領(lǐng)域的研究熱點(diǎn)。符號(hào)有向圖(SDG)由于具有良好的信息完備性，不需要精確的數(shù)學(xué)模型即可快速地描繪出故障的傳播過(guò)程，以及反映不同工作狀態(tài)下變量間的相互作用關(guān)系等優(yōu)點(diǎn)，被廣泛應(yīng)用于工業(yè)的故障診斷與故障定位。 傳統(tǒng)SDG包含的定性信息無(wú)法描述故障的嚴(yán)重程度，在進(jìn)行復(fù)雜系統(tǒng)推理時(shí)需要大量時(shí)間，對(duì)于多個(gè)候選故障源無(wú)法進(jìn)一步分辨�，F(xiàn)有的SDG診斷方法大多從某一角度對(duì)傳統(tǒng)SDG進(jìn)行改進(jìn)，會(huì)導(dǎo)致一些問(wèn)題的出現(xiàn)，如對(duì)SDG模型進(jìn)行信息擴(kuò)充后，系統(tǒng)的診斷效率降低；忽略了故障動(dòng)態(tài)信息，無(wú)法精確的定位故障源等。為了解決這些問(wèn)題，本文提出了一種綜合故障診斷方法，從模型、結(jié)構(gòu)、推理三個(gè)方面對(duì)SDG模型進(jìn)行了改進(jìn)。 傳統(tǒng)SDG模型中，模型定量信息不足，故障的分辨率較差。變量節(jié)點(diǎn)只有三種狀態(tài)，包含的故障信息較少。節(jié)點(diǎn)狀態(tài)是根據(jù)閾值建立的，而閾值的設(shè)定是判斷系統(tǒng)是否故障的重要標(biāo)準(zhǔn)。傳統(tǒng)SDG模型的建立依托了單一閾值的設(shè)定，節(jié)點(diǎn)只描述了故障是否發(fā)生，，并沒(méi)有反映出故障的嚴(yán)重程度。同時(shí)由于測(cè)量過(guò)程中噪聲的存在，清晰值無(wú)法準(zhǔn)確的描述故障信息，這就需要用更為完備的方法來(lái)描述系統(tǒng)變量。為了彌補(bǔ)SDG模型分辨率低及定量信息不足的缺點(diǎn)，本文將三級(jí)狀態(tài)擴(kuò)展為五級(jí)狀態(tài)，同時(shí)引入了模糊集合理論，得到了一種模糊五級(jí)SDG模型。 擴(kuò)充模型信息會(huì)增大系統(tǒng)結(jié)構(gòu)的復(fù)雜性，提高了搜索的難度。將SDG模型按照分層策略進(jìn)行層次化處理，能夠簡(jiǎn)化模型的結(jié)構(gòu)。另外，分層后的SDG模型中，故障只能由高層向低層傳播，從而能夠快速得到候選故障源，減少了搜索空間。 故障的搜索通常采用回溯搜索，但由于診斷信息不足，無(wú)法進(jìn)一步搜索故障源。本文從推理角度引入了故障定位算法，通過(guò)公共點(diǎn)的設(shè)定，將故障源定位問(wèn)題轉(zhuǎn)化為相容通路優(yōu)先級(jí)的排序問(wèn)題，同時(shí)引入了故障放大倍數(shù)、故障支持度和故障速度來(lái)定位故障源，提高了故障定位的精度，彌補(bǔ)了傳統(tǒng)SDG只包含靜態(tài)信息的缺點(diǎn)。最后以TEP過(guò)程為例進(jìn)行故障模擬分析，驗(yàn)證該方法的有效性。仿真結(jié)果表明，該方法高效準(zhǔn)確，具有良好的信息完備性與故障定位能力，對(duì)減少設(shè)備損耗及提高化工系統(tǒng)的安全性起到了推動(dòng)作用。
[Abstract]:With the development of science and technology, the complexity of chemical process is increasing and developing towards the trend of large scale and automation. The raw materials of chemical production are flammable and explosive, and the production environment is generally in extreme conditions, so the failure will cause great harm. How to quickly and efficiently infer and determine the fault source has become a research hotspot in the field of chemical safety. The symbol directed graph (SDG) has the advantages of good completeness of information, it can describe the process of fault propagation quickly without the need of accurate mathematical model, and reflect the interaction relationship between variables under different working conditions, and so on. It is widely used in industrial fault diagnosis and fault location. The qualitative information contained in the traditional SDG can not describe the severity of the fault. It takes a lot of time to infer the complex system and can not be further distinguished for multiple candidate fault sources. Most of the existing SDG diagnosis methods improve the traditional SDG from a certain point of view, which will lead to some problems. For example, after extending the SDG model, the diagnosis efficiency of the system is reduced, and the fault dynamic information is ignored. Unable to pinpoint the source of the fault, etc. In order to solve these problems, a comprehensive fault diagnosis method is proposed in this paper. The SDG model is improved from three aspects: model, structure and reasoning. In the traditional SDG model, the quantitative information is insufficient and the fault resolution is poor. Variable nodes have only three states and contain less fault information. The node state is established according to the threshold, and the threshold setting is an important criterion to judge whether the system is fault or not. The traditional SDG model is based on the setting of a single threshold, and the node only describes whether the fault occurs or not, and does not reflect the severity of the fault. At the same time, due to the presence of noise in the measurement process, the clear value can not accurately describe the fault information, which requires a more complete method to describe the system variables. In order to make up for the shortcomings of low resolution and insufficient quantitative information of SDG model, this paper extends the three-level state to five-level state, introduces fuzzy set theory, and obtains a fuzzy five-stage SDG model. Extending the model information will increase the complexity of the system structure and increase the difficulty of searching. The structure of SDG model can be simplified by hierarchical processing according to stratification strategy. In addition, in the layered SDG model, the fault can only propagate from the high level to the lower level, thus the candidate fault source can be obtained quickly and the search space can be reduced. Backtracking is usually used in fault search, but it is impossible to search for fault source because of insufficient diagnosis information. In this paper, a fault location algorithm is introduced from the point of view of reasoning. By setting common points, the problem of fault source location is transformed into a priority ranking problem of compatible paths, and the fault magnification is also introduced. Fault support and fault speed are used to locate the fault source, which improves the accuracy of fault location and makes up for the shortcoming that the traditional SDG only contains static information. Finally, the TEP process is taken as an example for fault simulation analysis to verify the effectiveness of the method. The simulation results show that the method is efficient and accurate, has good information completeness and fault location ability, and plays an important role in reducing equipment loss and improving the safety of chemical system.
【學(xué)位授予單位】：太原理工大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類(lèi)號(hào)】：TQ086
[Abstract]:With the development of science and technology, the complexity of chemical process is increasing and developing towards the trend of large scale and automation. The raw materials of chemical production are flammable and explosive, and the production environment is generally in extreme conditions, so the failure will cause great harm. How to quickly and efficiently infer and determine the fault source has become a research hotspot in the field of chemical safety. The symbol directed graph (SDG) has the advantages of good completeness of information, it can describe the process of fault propagation quickly without the need of accurate mathematical model, and reflect the interaction relationship between variables under different working conditions, and so on. It is widely used in industrial fault diagnosis and fault location. The qualitative information contained in the traditional SDG can not describe the severity of the fault. It takes a lot of time to infer the complex system and can not be further distinguished for multiple candidate fault sources. Most of the existing SDG diagnosis methods improve the traditional SDG from a certain point of view, which will lead to some problems. For example, after extending the SDG model, the diagnosis efficiency of the system is reduced, and the fault dynamic information is ignored. Unable to pinpoint the source of the fault, etc. In order to solve these problems, a comprehensive fault diagnosis method is proposed in this paper. The SDG model is improved from three aspects: model, structure and reasoning. In the traditional SDG model, the quantitative information is insufficient and the fault resolution is poor. Variable nodes have only three states and contain less fault information. The node state is established according to the threshold, and the threshold setting is an important criterion to judge whether the system is fault or not. The traditional SDG model is based on the setting of a single threshold, and the node only describes whether the fault occurs or not, and does not reflect the severity of the fault. At the same time, due to the presence of noise in the measurement process, the clear value can not accurately describe the fault information, which requires a more complete method to describe the system variables. In order to make up for the shortcomings of low resolution and insufficient quantitative information of SDG model, this paper extends the three-level state to five-level state, introduces fuzzy set theory, and obtains a fuzzy five-stage SDG model. Extending the model information will increase the complexity of the system structure and increase the difficulty of searching. The structure of SDG model can be simplified by hierarchical processing according to stratification strategy. In addition, in the layered SDG model, the fault can only propagate from the high level to the lower level, thus the candidate fault source can be obtained quickly and the search space can be reduced. Backtracking is usually used in fault search, but it is impossible to search for fault source because of insufficient diagnosis information. In this paper, a fault location algorithm is introduced from the point of view of reasoning. By setting common points, the problem of fault source location is transformed into a priority ranking problem of compatible paths, and the fault magnification is also introduced. Fault support and fault speed are used to locate the fault source, which improves the accuracy of fault location and makes up for the shortcoming that the traditional SDG only contains static information. Finally, the TEP process is taken as an example for fault simulation analysis to verify the effectiveness of the method. The simulation results show that the method is efficient and accurate, has good information completeness and fault location ability, and plays an important role in reducing equipment loss and improving the safety of chemical system.
【學(xué)位授予單位】：太原理工大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類(lèi)號(hào)】：TQ086
【參考文獻(xiàn)】
相關(guān)期刊論文 前10條
1 宋建成;間歇過(guò)程自動(dòng)化的進(jìn)展[J];化工進(jìn)展;1996年03期
2 張貝克;鄭然;馬昕;吳重光;;間歇過(guò)程動(dòng)態(tài)SDG建模[J];化工學(xué)報(bào);2008年07期
3 盧秉南;張貝克;馬昕;許欣;高東;;基于SDG模型的控制系統(tǒng)故障診斷方法[J];化工學(xué)報(bào);2009年09期
4 王杭州;陳丙珍;何小榮;趙勁松;邱彤;;基于開(kāi)源組件的SDG推理平臺(tái)[J];化工學(xué)報(bào);2010年07期
5 黃衛(wèi)東,王克昌,黃衛(wèi)東;基于定性和定量關(guān)系的液體火箭發(fā)動(dòng)機(jī)故障診斷[J];航空動(dòng)力學(xué)報(bào);1996年03期
6 宋其江;徐敏強(qiáng);王日新;;基于分層有向圖的航天器故障診斷[J];航空學(xué)報(bào);2009年06期
7 吳軍強(qiáng),梁軍;基于圖論的故障診斷技術(shù)及其發(fā)展[J];機(jī)電工程;2003年05期
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