礦井提升機(jī)—主軸裝置設(shè)計(jì)
礦井提升機(jī)—主軸裝置設(shè)計(jì),礦井提升機(jī)—主軸裝置設(shè)計(jì),礦井,提升,晉升,主軸,裝置,設(shè)計(jì)
河南理工大學(xué)萬方科技學(xué)院
本科畢業(yè)設(shè)計(jì)(論文)中期檢查表
指導(dǎo)教師: 牛振華 職稱: 講師
所在系部(單位): 機(jī)械動(dòng)力與工程學(xué)院 教研室(研究室): 機(jī)設(shè)教研室
題 目
礦井提升機(jī)—主軸裝置設(shè)計(jì)
學(xué)生姓名
郭斌斌
專業(yè)班級(jí)
機(jī)設(shè)08-2班
學(xué)號(hào)
0828070038
一、選題質(zhì)量
(主要從以下四個(gè)方面填寫:1、選題是否符合專業(yè)培養(yǎng)目標(biāo),能否體現(xiàn)綜合訓(xùn)練要求;2、題目難易程度;
3、題目工作量;4、題目與生產(chǎn)、科研、經(jīng)濟(jì)、社會(huì)、文化及實(shí)驗(yàn)室建設(shè)等實(shí)際的結(jié)合程度)
1, 該選題為礦井提升機(jī)—主軸裝置設(shè)計(jì),可以對(duì)我們大學(xué)四年所學(xué)知識(shí)進(jìn)行一次大而全面的練習(xí)。
2, 這將對(duì)我們以后工作起到十分有效的幫助,也能達(dá)到一個(gè)綜合訓(xùn)練的效果,又加強(qiáng)
了實(shí)際的動(dòng)手動(dòng)腦能力。
3, 題目的難易程度很適中,對(duì)我們既是一個(gè)挑戰(zhàn)也是一個(gè)很好的鍛煉提高過程。
4, 題目的工作量:要求完成3.5張以上的A0圖紙,2.5—3萬的說明書一份。
5, 選題不但能緊密的結(jié)合生產(chǎn)和實(shí)踐,也是在我們所學(xué)習(xí)過的范圍之類,對(duì)我們
以后不管是科研還是從事實(shí)際的工作對(duì)有很大的幫助。
二、開題報(bào)告完成情況
在老師指導(dǎo)和同學(xué)們的幫助之下,我順利的開始我本次畢業(yè)設(shè)計(jì)。我在自己經(jīng)過一些查閱資料的前提下,慢慢的摸索出了一些門道。
由于我們這次是第一次獨(dú)立的礦井提升機(jī)—主軸裝置設(shè)計(jì),在以前接觸這方面的知識(shí)較少,所以在剛開始就不是很順利,甚至感到有些無從下手,但是經(jīng)過和指導(dǎo)老師的提示和與本組同學(xué)的商量之后, 我逐漸找到是設(shè)計(jì)的切入點(diǎn),順利的完成了開題報(bào)告。并有了一定的成果和進(jìn)行了一些前期的工作,并使本次設(shè)計(jì)有了一個(gè)良好的開始。最后我在查閱了一些資料以后,現(xiàn)在已經(jīng)進(jìn)入了計(jì)算設(shè)計(jì)過程,我將在以后工作中繼續(xù)努力,認(rèn)真完成這次畢業(yè)設(shè)計(jì)。
三、階段性成果
1.通過對(duì)礦井提升機(jī)系統(tǒng)的學(xué)習(xí),在加上老師的仔細(xì)講解,我收集了大量的資料和文獻(xiàn),為設(shè)計(jì)的順利完成打下了堅(jiān)實(shí)的基礎(chǔ)。
2. 在老師的指導(dǎo)和同學(xué)的幫助下找到了設(shè)計(jì)的基本方法,開始了一些基本的原理
設(shè)計(jì),并取得了一定成果。
3. 完成了開題報(bào)告。
4.進(jìn)行了前期的一些工作和設(shè)計(jì),對(duì)整個(gè)設(shè)計(jì)有了一個(gè)大體的方案。
四、存在主要問題
由于我們這次是第一次獨(dú)立的礦井提升機(jī)—主軸裝置設(shè)計(jì),所以在剛開始就不是很順利,對(duì)做一個(gè)畢業(yè)設(shè)計(jì)的基本知識(shí)都沒有認(rèn)識(shí),后來找了指導(dǎo)老師,老師給我在他去年指導(dǎo)畢業(yè)設(shè)計(jì)的基礎(chǔ)上,針對(duì)我們本科生以前存在的問題,進(jìn)行了仔細(xì)的講解,然后我再與本組其他同學(xué)的商量之后,我慢慢的自己逐漸找到是設(shè)計(jì)的切入點(diǎn),我覺得這對(duì)我以后有很大的作用。
但是隨著設(shè)計(jì)的逐漸進(jìn)行我有遇到了許多的新的和更加復(fù)雜的問題,這些問題使我充
分認(rèn)識(shí)到了自己在以前學(xué)習(xí)中的不足和自己與一些同學(xué)的差距,所以我要以本次設(shè)計(jì)問契機(jī)
加強(qiáng)自己在學(xué)習(xí)上薄弱環(huán)節(jié),爭取使我的畢業(yè)設(shè)計(jì)能夠取得好的成績,也能夠使我所學(xué)的知
識(shí)能夠在以后的工作中發(fā)揮更大的作用。
五、指導(dǎo)教師對(duì)學(xué)生在畢業(yè)實(shí)習(xí)中,勞動(dòng)、學(xué)習(xí)紀(jì)律及畢業(yè)設(shè)計(jì)(論文)進(jìn)展等方面的評(píng)語
指導(dǎo)教師: (簽名)
年 月 日
本科畢業(yè)設(shè)計(jì)(論文)
中英文對(duì)照翻譯
院(系部) 萬方科技學(xué)院機(jī)械與動(dòng)力工程系
專業(yè)名稱 機(jī)械設(shè)計(jì)制造及其自動(dòng)化
年級(jí)班級(jí) 機(jī)設(shè)08-2班
學(xué)生姓名 郭斌斌
指導(dǎo)老師 牛振華
2012年5月
河南理工大學(xué)萬方科技學(xué)院
本科畢業(yè)設(shè)計(jì)(論文)開題報(bào)告
題目名稱
礦井提升機(jī)—主軸裝置設(shè)計(jì)
學(xué)生姓名
郭斌斌
專業(yè)班級(jí)
機(jī)設(shè)08-2班
學(xué)號(hào)
0828070038
一、選題的目的和意義
礦井提升機(jī)是礦山的大型固定設(shè)備之一,是聯(lián)系井下與地面的主要運(yùn)輸工具。礦井提升工作是整個(gè)采礦過程中的重要環(huán)節(jié)。從地下采出的煤炭、礦石必須提升至地面才有實(shí)際應(yīng)用價(jià)值。廢石的提升,工作人員、材料及設(shè)備的升降等都要靠提升工作來完成。礦井提升設(shè)備就是完成上述工作的多種機(jī)電設(shè)備組成的大型成套裝備。
選擇礦井提升機(jī)主軸組件設(shè)計(jì)能夠掌握和加深領(lǐng)會(huì)設(shè)計(jì)計(jì)算的基本理論和深化所學(xué)的理論知識(shí)。樹立正確的設(shè)計(jì)思想和思路,為以后在工作中遇到相關(guān)問題提供解決依據(jù)。通過本次畢業(yè)設(shè)計(jì),能夠?qū)ΦV井提升機(jī)有個(gè)全面的認(rèn)識(shí),對(duì)礦井提升機(jī)主軸的結(jié)構(gòu)、組成、功能和性能等都有了全面的認(rèn)知,能夠獨(dú)立的完成設(shè)計(jì)對(duì)自己設(shè)計(jì)能力和實(shí)踐能力都有很大的提高,不僅僅在理論上加深認(rèn)知,更通過自己實(shí)際的設(shè)計(jì)操作使自己的動(dòng)手能力有了很大的提高。通過本次設(shè)計(jì)能使我們把先前學(xué)習(xí)的基礎(chǔ)和專業(yè)基礎(chǔ)課程中所獲得的理論知識(shí)在實(shí)際的設(shè)計(jì)工作中綜合地加以應(yīng)用,通過畢業(yè)設(shè)計(jì)能夠熟練應(yīng)用有關(guān)參考資料、計(jì)算圖表、手冊(cè)等相關(guān)資料;熟悉有關(guān)的國家標(biāo)準(zhǔn)和頒部標(biāo)準(zhǔn),為以后成為優(yōu)秀的工程技術(shù)人員打下良好的基礎(chǔ),也為以后工作積累一些經(jīng)驗(yàn)。
二、國內(nèi)外研究綜述
礦山提升機(jī)是礦山大型固定機(jī)械之一,礦山提升機(jī)從最初的蒸汽機(jī)拖動(dòng)的單繩纏繞式提升機(jī)發(fā)展到今天的交—交變頻直接拖動(dòng)的多聲摩擦式提升機(jī)和雙繩纏繞式提升機(jī),經(jīng)歷了170多年的發(fā)展史。目前,國內(nèi)外經(jīng)常使用的提升機(jī)有但繩纏繞式和多繩摩擦式兩種形式,它的主回路和磁場回路均采用電力電子器件,實(shí)現(xiàn)變頻和整流。由于采集設(shè)備,是井下與地面聯(lián)系的重要工具。
電力電子技術(shù)較早就用于礦井提升機(jī)的傳動(dòng),并且發(fā)展迅速,從60年代的模擬控制SCR-D直流提升機(jī)發(fā)展到目前最先進(jìn)的同步機(jī)內(nèi)用交流電機(jī),沒有電刷問題,提升機(jī)容量可以大幅度增加,例如南非帕拉波礦井內(nèi)裝式提升機(jī)電機(jī)功率達(dá)6300kW。我國東歡坨、大雁、陳四樓等礦均引進(jìn)了內(nèi)裝式提升機(jī)。目前,全數(shù)字電力電子器件構(gòu)成的國產(chǎn)直流提升機(jī)已占領(lǐng)了國內(nèi)市場,并開始出口。但是由于我國的科技和生產(chǎn)水平的限制,我國的礦井提升機(jī)還有很大一部分需要依賴于進(jìn)口。
三、畢業(yè)設(shè)計(jì)所用的方法
1.在圖書館借閱相關(guān)書籍、論文等,并進(jìn)行整理。
2.在學(xué)校數(shù)據(jù)庫查找相關(guān)資料。
3.在網(wǎng)上查找相關(guān)資料。
4.對(duì)找到的資料和數(shù)據(jù)進(jìn)行分析和計(jì)算。
5.整合查到的數(shù)據(jù)和資料開始寫畢業(yè)論文。
6.論文撰寫按構(gòu)思框架、編寫提綱、專題研討幾個(gè)步驟進(jìn)行。在編寫過程中征求老師和同學(xué)的意見使論文內(nèi)容更加全面。
四、主要參考文獻(xiàn)與資料獲得情況
【1】洪曉華,礦井提升運(yùn)輸(第二版).徐州:中國礦業(yè)大學(xué)出版社,2005
【2】潘英等,通用機(jī)械設(shè)計(jì)[M].徐州:中國礦業(yè)大學(xué)出版社,2003
【3】洪曉華,陳軍.礦井運(yùn)輸提升. 徐州:中國礦業(yè)大學(xué)出版社,2005
【4】謝錫純,李曉豁.礦山機(jī)械與設(shè)備(第二版). 徐州:中國礦業(yè)大學(xué)出版社,2007
【5】潘英,礦山機(jī)械提升設(shè)計(jì). 徐州:中國礦業(yè)大學(xué)出版社,2000
【6】李儀鈺,礦山提升運(yùn)輸機(jī)械.北京:冶金工業(yè)出版社,1989
【7】于忠升,宋偉剛. 礦山運(yùn)輸提升.沈陽:東北大學(xué)出版社,1992
五、指導(dǎo)教師審批意見
指導(dǎo)教師: (簽名)
年 月 日
外文資料:
Research on Detection Device for Broken Wires of Coal Mine-Hoist Cable
WANG Hong-yao1, HUA Gang1, TIAN Jie2
1School of Information and Electrical Engineering, China University of Mining & Technology, Xuzhou, Jiangsu 221008, China
2School of Mechanical Electronic and Information Engineering, China University of Mining & Technology, Beijing 100083, China
Abstract: In order to overcome the flaws of present domestic devices for detecting faulty wires such as low precision,low sensitivity and instability, a new instrument for detecting and processing the signal of flux leakage caused by broken wires of coal mine-hoist cables is investigated. The principle of strong magnetic detection was adopted in the equipment. Wires were magnetized by a pre-magnetic head to reach magnetization saturation. Our special feature is that the number of flux-gates installed along the circle direction on the wall of sensors is twice as large as the number of strands in the wire cable. Neighboring components are connected in series and the interference on the surface of the wire cable, produced by leakage from the flux field of the wire strands, is efficiently filtered. The sampled signal sequence produced by broken wires, which is characterized by a three-dimensional distribution of the flux-leakage field on the surface of the wire cable, can be dimensionally condensed and characteristically extracted. A model of a BP neural network is built and the algorithm of the BP neural network is then used to identify the number of broken wires quantitatively. In our research, we used a 6×37+FC, 24 mm wire cable as our test object. Randomly several wires were artificially broken and damaged to different degrees. The experiments were carried out 100 times to obtain data for 100 groups from our samples. The data were then entered into the BP neural network and trained. The network was then used to identify a total 16 wires, broken at five different locations. The test data proves that our new device can enhance the precision in detecting broken and damaged wires.
Key words: wire cable; broken wire; signal processing; detection device
CLC number: TB 42
1 Introduction
It is well-known that coal mine-hoist cables are an important part in coal mine-hoists or transportation systems. Wires are, in fact, subjected to breakage due to wear, corrosion and fatigue. The extent of damage and the carrying capacity of wires are directly related to the safety of equipment and staff. At present, there are many detection devices for broken steel cables manufactured in China, but most devices do not meet the conditions ideally required in practice. The reasons are largely the complex structure of wires, bad working conditions, the multiplicity and uncertainty of broken wires. It is therefore quite difficult to detect signs of broken wires as well as to analyze and process detected signal of broken wires in cables [1].A new instrument for broken wires detection and procession of coal mine-hoist cables was investigatedfor this paper. With the special structure of a detection transducer, the interfering signal from the leakage field of wire twists can be filtered efficiently. After the extraction of dimensional contraction and characteristic values of multi-ways signals, a quantitative BP neural network recognition for broken wires in steel cables was realized. The test results are presented.
2 Basic Structural Principle of the On-Line Detection Instrument for Coal Mine-Hoist Cable
The structural principle of the on-line detection device for wire cables studied by us is shown in Fig. 1.The detection transducer is composed of two semicircle cylindrical structures which can be opened or closed. The magnetic sensing unit is a fluxgate unit made of a single magnetic core and is single-winding. Some magnetic sensing units are evenly arranged around the inner wall of the transducer, the number of which is twice as many as the number of the wire strands in the inspected cable. As well, two neighboring units are connected in series to a detection channel.Consequently, the number of detection channels of the detection instrument is equal to the number of wire strands in the cable.
Fig. 1 Structural principle of detection instrument
for broken wires in coal mine-hoist cables.
After being filtered and reshaped, the detection signal from each channel is sent to the signal processing unit. The analog detection signal is converted into adiscrete dimensional sequence of sampling values by multi-channel A/D conversion, followed by a characteristic extraction, a BP neural network recognition and the output of the result. When viewed separately, the leakage field signal detected by each single fluxgate unit is the leakage field intensity in the steel cable where the corresponding fluxgate units are located. That is, the outputsignal Zjk of any jth test unit is:
where FC is the structural parameter of the fluxgate, the width of the drive square-wave, s the saturated magneto-conductivity rate, B c, j the magnetic
induction intensity of the leakage field produced by broken wires, Br, j the magnetic induction intensity of the leakage field produced by wire cable twists, Zf j the signal value of broken wires and Z r, j the value of the interference signal produced by wire cable twists.
After , F C ,a , us , Fare assured, F is a constant.After the wire cables are deeply magnetized, the numerical value of sis very small. As a result, the value of c, j is larger and there is no need to magnify and process the detection signal again. When the sensor is operating along wire cables at a specified speed, the signals detected by each of the magnetic fluxgate units can effectively show the three-dimensional distribution status of magnetic flux leakage, generated at the surface of wire cables[2–4].
3 Filtration of the Wavelike Oscillation Interference Signal Produced by Cable Wire Twists
The signal of broken wires from wire cables obtained by a single fluxgate detection unit of the transducer (formula (1)) contains all kinds of interfering signals. The effect of the wavelike oscillation magnetic flux leakage B r, j due to the special structure of the steel cables is largest, which directly affects the detection of broken or damaged wires, especially in coal mine-hoist cables. We should consider the possibility of filtering the interference signals. In formula (1), the interference signal r, j caused by a wavelike oscillation shows up as periodic variation. This kind of wavelike oscillation interferencesignal can be regarded approximately as a sine wave,as shown in Fig. 2.
Fig. 2 Wavelike oscillation interference signal
produced by the cable twist
Over the length direction of wire cables, its variation period T is a Lay length of cable wire strands. At the circle direction of the wire cable, its variation period is the reciprocal of the number of outer wire strands of the circle length of the wire cable. Therefore, the wavelike oscillation interference signal of the jth detection channel can be expresse d as:
j
where a is the Direct Current Component of the wavelike oscillation signal, m the Alternating Current Component magnitude of the wavelike oscillartion signal, T represents the value of periods, y is the position of the detection unit, starting from the initial spot, j the initial phase of the wavelike oscillation signal, N the number of wire strands of the steel cable, and is the number of detection units. cObviously when c , i.e., when the number of detection units doubles the number of outer strands of the wire cable, the wavelike oscillation signal contained in the leakage magnetic field signal inspected by any two neighboring detection units is in a reversal phase. Therefore, when the neighboring detection units along the inner wall of the cylinder of the transducer structure are connected forward into a test channel in series two by two, it is equivalent to adding the (j+1)th test channel signal to the jth test channel signal. Thus the strand peak value of the wavelike oscillation signal compensates for the strand value for the moment. That is, at this moment, the only remaining wavelike oscillation signal is the Direct Current Componen
At this moment, the magnetic field signal of leakage from any of the inspection channels made up of the fluxgate array should be:
of this formula can be eliminated when the zero detection position is adjusted. Therefore, we considered that the wavelike oscillation interference signal of cable wires is filtered by formula (4). After this pretreatment, each leakage from broken wires, shown by magnetic field signals from the transducer, becomes a channel sample value by A/D conversion, as shown in Fig. 3.
Fig. 3 Multi-channel sampling value of broken wire
signals from wire cables
4 Extraction of Characteristic Value of Signals from Broken Wires
As is shown in Fig. 3, the N-channel inspection signals from the transducer becomes its sampling sequence by A/D conversion. If the number of samples of the signals of broken wires is K, the sequence of broken wire sample signals of the jth channel can be expressed as a row vector with K elements.
The N-channel signal sequence will make up a N-dimensional series vector group of broken wiresignals:
At this moment, Z is a characteristic matrix of broken wires and it contains all the information on the status of the broken wires. NK Given the analysis of repeated experiments, the width of the diffused leakage from the magnetic fieldon the surface of wire cables created by broken wires is not larger than 20 mm. When the speed of the inspected wire cable is 3 m/s and the sampling interval is 1.2 mm, the number of samples K is 16 at most. When the number of inspection channels is N=4, Z should be a 4×16 matrix. If the analysis of the characteristic matrix of broken or damaged wires Z were directly carried out, the analytical process would be very complex and would need to be carried out as acomparison and judgment of the sequential value of each line. So instead, we carried out a reduction in the order processing of formula (6), i.e., we carried out a dimensional contraction. According to a lemma of theoretical linear algebra Z can also be expressed as:
where are arbitrary, independent base vectors. h is the characteristic vector of one-dimensional broken wires expected to be obtained after dimensionalcontraction. So long as the appropriate t is found, h can be derived:
According to the L-K transformation principle, when the value of t is the latent vector of the covariance matrix z P of Z, the transformation error is a minimum, i.e., t satisfies the characteristic equation
where j is the characteristic value of z and I is an identity matrix. Represented by formula (8), the expected characteristic vector h of the broken wires could be obtained via the dimensional contraction. The process of transformation of the dimensional contraction is, in fact, a conversion from a N-dimensional characteristic vector to a one-dimensional vector. P The average of the one-dimensional h sequence is regarded as an eigenvector which represents each state of the N-channel broken wire signals:
5 Conclusions
Our detection of broken wires in steel cables is a quantitative inspection method. It will identify not only whether there are broken wires or not, but also will identify the position and number of broken wires. By combining transducer detection technology and computer technology and using advanced signal processing technology, we can effectively enhance the
precision and sensitivity of detection devices to realize the automation and the intellectualization of the detection equipment.
中文翻譯:
對(duì)煤礦礦井提升機(jī)鋼絲繩損毀的鋼絲檢測(cè)裝置的研究
王宏姚,華崗, 田杰
1信息和電氣工程系,中國礦業(yè)科技大學(xué),江蘇徐州221008 ,中國
2機(jī)械電子信息工程系,中國礦業(yè)科技大學(xué),北京100083 ,中國
摘要:
為了克服目前國內(nèi)鋼絲故障檢測(cè)設(shè)備的缺陷,如低精度,低靈敏度和不穩(wěn)定,一個(gè)新的由煤礦-提升機(jī)鋼絲繩所造成的漏磁信號(hào)的檢測(cè)和處理裝置已經(jīng)研制出。強(qiáng)磁場檢測(cè)的原理應(yīng)用在該設(shè)備中,鋼絲由前磁頭磁化強(qiáng)度達(dá)到飽和。我們特別的特點(diǎn)是安裝在沿圓圈方向上傳感器的內(nèi)壁數(shù)目通量是在鋼絲繩中兩倍大的數(shù)目。周邊組件系列地連接在一起并且由于鋼絲的通量域所產(chǎn)生的滲漏對(duì)鋼絲繩的表面干擾有效地被過濾,,斷絲所產(chǎn)生的采樣信號(hào)序列,其特點(diǎn)是在線纜的表面上由一個(gè)三維分布漏磁場通量,可以立體簡明和根據(jù)特性提取。BP神經(jīng)網(wǎng)絡(luò)的模型已經(jīng)被建立和BP神經(jīng)網(wǎng)絡(luò)的算法是用來定量分析地確定有多少鋼絲損毀。在我們的研究,我們用了6 × 37 +FC, 24毫米線纜作為我們的測(cè)試對(duì)象。隨機(jī)人為地以不同程度破壞和損壞數(shù)根鋼絲,實(shí)驗(yàn)共進(jìn)行了100次,以為來自我們的樣本的100組對(duì)象獲取數(shù)據(jù), 然后將數(shù)據(jù)輸進(jìn)BP神經(jīng)網(wǎng)絡(luò)進(jìn)行處理。然后該網(wǎng)絡(luò)用來識(shí)別共計(jì)16鋼絲,打破了5個(gè)不同地點(diǎn)。測(cè)試數(shù)據(jù)證明我們的新裝置可以提高檢測(cè)破碎和損壞的鋼絲的檢測(cè)精度。
關(guān)鍵詞:鋼絲繩;損壞的鋼絲;信號(hào)處理;檢測(cè)裝置
中圖分類號(hào)TB 42
1 引言
煤礦提升機(jī)鋼絲繩是煤礦提升或運(yùn)輸系統(tǒng)的重要組成部分,這是人所共知的。事實(shí)上鋼絲是,由于磨損,腐蝕和疲勞而受到破損,。鋼絲的損害程度和承載能力直接關(guān)系到設(shè)備和員工的安全。目前, 很多在中國制造的檢測(cè)損壞的鋼絲繩裝置,但大多數(shù)設(shè)備不能理想地滿足實(shí)踐需要,原因主要是鋼絲的復(fù)雜結(jié)構(gòu),惡劣的工作條件,鋼絲損毀的多重性和不確定性。因此,檢測(cè)到鋼絲損毀的跡象是相當(dāng)困難,以及作以分析和處理在鋼絲繩[ 1 ]里檢測(cè)到的鋼絲損毀的信號(hào)也是如此 。在此論文中,一套新的煤礦-提升機(jī)鋼絲繩和斷絲檢測(cè)設(shè)備
已經(jīng)深入探討,用傳感器檢測(cè)的特殊結(jié)構(gòu),從鋼絲扭曲而產(chǎn)生的泄漏領(lǐng)域的干擾信號(hào),可以有效地過濾。在…之后提取多途徑的信號(hào)的三維收縮和特征值, BP神經(jīng)網(wǎng)絡(luò)在鋼絲繩對(duì)斷絲的識(shí)別得已定量地實(shí)現(xiàn),該測(cè)試結(jié)果將會(huì)顯示出來。
2 聯(lián)機(jī)的煤礦提升機(jī)鋼絲繩檢測(cè)儀的基本結(jié)構(gòu)原理
我們研究的該聯(lián)機(jī)的鋼絲繩檢測(cè)裝置的結(jié)構(gòu)原理在圖 1中已經(jīng)表明 。 檢測(cè)傳感器由兩個(gè)可開啟或封閉的半圓圓筒形結(jié)構(gòu)組成,磁傳感單元是一種由一個(gè)單一的磁芯組成磁通門單元并且是單一繞組。一些磁性傳感單元均勻地安排靠近轉(zhuǎn)換器的內(nèi)壁,它的數(shù)量是檢測(cè)鋼絲繩鐵絲網(wǎng)的兩倍以及,兩個(gè)相鄰的單元有系列地聯(lián)接在一項(xiàng)檢測(cè)通道。 因此,該檢測(cè)儀的檢測(cè)通道的數(shù)量與絲股在線纜的數(shù)量相等。
如下列圖表1: 煤礦提升機(jī)鋼絲繩鋼絲損毀檢測(cè)儀的結(jié)構(gòu)原理,經(jīng)過過濾和重塑,從每個(gè)通道發(fā)出的檢測(cè)信號(hào)送到信號(hào)處理單元。通過多渠道的A / D轉(zhuǎn)換,模擬檢測(cè)信號(hào)轉(zhuǎn)化為二維離散序列的采樣值,然后通過BP神經(jīng)網(wǎng)絡(luò)的識(shí)別和結(jié)果的輸出特點(diǎn)提取。檢測(cè)時(shí),另外,通過每個(gè)單磁通門單元檢測(cè)到的漏磁場信號(hào)是泄漏在鋼索的地方相應(yīng)的磁通門單元的電場強(qiáng)度, 那就是,任何jth測(cè)試單元的輸出信號(hào)Zcj是:
在該公式中,CF是驅(qū)動(dòng)器方波的磁通門 寬度的結(jié)構(gòu)參數(shù), S 是額定定磁導(dǎo)率, Bcj鋼絲損毀漏磁場所產(chǎn)生的應(yīng)強(qiáng)度,Brj是鋼絲繩曲折所產(chǎn)生的漏磁場的磁感應(yīng)強(qiáng)度, Zfj損毀鋼絲的信號(hào)值,和Zrj是的鋼絲繩扭曲所產(chǎn)生干擾信號(hào)值,公式中系數(shù)
在Cf,a,s,D確定以后,是一個(gè)常數(shù)。 線鋼絲繩深感磁化后, US的數(shù)值 是很小的。因此, Zcj的值會(huì)更大,因此,沒有必要再次去放大和處理的檢測(cè)信號(hào)。 當(dāng)傳感器是在指定的速度下沿鋼絲繩運(yùn)行,每一項(xiàng)磁通門單位檢測(cè)到的信號(hào),能有效地顯示磁泄漏三維立體分布狀況,在鋼絲繩表面產(chǎn)生 [ 2-4 ] 。
3 鋼絲繩扭曲所產(chǎn)生的干擾信號(hào)的波形振蕩的過濾
由一個(gè)單一的磁通門檢測(cè)單元所獲得的鋼絲繩損毀鋼絲的信號(hào), (公式( 1 ))包含各種干擾信號(hào)。由于鋼絲繩特殊結(jié)構(gòu)產(chǎn)生的磁通量泄露強(qiáng)度Bjb的波形振蕩影響是最大地,這直接影響到檢測(cè)的破碎或損壞的鋼絲,特別是在煤礦-提升機(jī)的鋼絲繩。我們應(yīng)該考慮過濾干擾信號(hào)可能性。
在公式( 1 ) ,波形振蕩所造成的干擾信號(hào)Zrj周期地顯示。這種波形振蕩干擾信號(hào),可算是大約作為一個(gè)正弦波,如圖圖2所示:
圖2鋼絲繩扭曲波形振蕩所產(chǎn)生的干擾信號(hào)
通過鋼絲繩的長度方向,其震蕩周期T是一個(gè)奠定長度電纜絲。在鋼絲繩的循環(huán)方向,其震蕩周期是鋼絲繩圓周長度的外鋼絲數(shù)目的倒數(shù), 因此,jth檢測(cè)通道的波形振蕩干擾信號(hào)Zrj可
表示為:
這里Ra是振蕩直流電信號(hào)組成部分,Rm是波形震蕩信號(hào)的交流電組成量,T代表周期值, Y是檢測(cè)單元的位置,從最初的位置開始,初期階段波形振蕩信號(hào), n的數(shù)目絲股的鋼索,以及數(shù)是檢測(cè)單位。N是鋼絲繩中的鋼絲根數(shù)Nc是檢測(cè)單元的個(gè)數(shù). 顯然,當(dāng)Nc= 2 n ,即,當(dāng)檢測(cè)單元的數(shù)目是鋼絲繩外部鋼絲數(shù)目的雙倍,由任何兩個(gè)鄰的檢測(cè)單位產(chǎn)生的漏磁場信號(hào)的波形振蕩信號(hào)是在一個(gè)還原階段。因此,當(dāng)周邊的檢測(cè)單位,沿傳感器的結(jié)構(gòu)圓柱內(nèi)壁兩個(gè)兩個(gè)地系列連接著成為一個(gè)測(cè)試頻道,這是相當(dāng)于向jth測(cè)試通道信號(hào)添加了j+1次測(cè)試通道信號(hào)。因此,鋼絞線波形振蕩信號(hào)的峰值補(bǔ)償為鋼絞線的價(jià)值是當(dāng)務(wù)之急。這是,在這一刻,剩下的唯一波形振蕩信號(hào)是直流電量的組成部分
此時(shí),從任何檢查的渠道泄漏的磁場信號(hào),組成了該磁通門陣列應(yīng)該是:
當(dāng)零檢測(cè)位置被調(diào)整時(shí),這個(gè)公式的Zr可以被減掉,因此,我們可以認(rèn)為鋼絲繩的波形振蕩干擾信號(hào)是被式( 4)過濾了。這預(yù)處理后,損毀鋼絲的每個(gè)泄漏,由傳感器所表現(xiàn)出的磁場信號(hào),由A / D轉(zhuǎn)換,變成一個(gè)渠道采樣值,顯示在圖3
圖3來自鋼絲繩的斷鋼絲信號(hào)的多渠道的采樣值
4 從損毀的鋼絲信號(hào)的特征值提取
正像圖3所表示的那樣,,來自傳感器N通道檢查信號(hào)通過A / D轉(zhuǎn)換成為其采樣序列,如果損壞的鋼絲信號(hào)的采樣數(shù)值是K, jth渠道的損壞鋼絲樣本信號(hào)序列,可以表示為一個(gè)與K有關(guān)的行向量.
N通道信號(hào)序列將組成損壞鋼絲的信號(hào)的
一個(gè)n維向量組
:
此時(shí), Z是一個(gè)具有損毀鋼絲的矩陣的特點(diǎn),它包含所有損毀鋼絲的程度的信息。鑒于反復(fù)試驗(yàn)分析, 鋼絲繩表面上損壞的鋼絲所造成的擴(kuò)散泄漏磁場的寬度斷絲不大于20毫米。當(dāng)檢測(cè)到鋼絲繩的速度是3米/秒和采樣間隔是1.2毫米,樣本數(shù)目K至多是16。 當(dāng)檢查渠道數(shù)目是N = 4時(shí), Z 應(yīng)該是一個(gè)4 × 16矩陣。如果破碎或損壞的鋼絲z的特征矩陣分析直接進(jìn)行,分析過程將十分復(fù)雜,將需要對(duì)該序列每一行的值進(jìn)行作為比較和判斷。因此,相反,我們減少了一項(xiàng),在指令處理公式( 6 ) ,即,我們進(jìn)行了維收縮。根據(jù)一項(xiàng)引理理論線性代數(shù),z也可以表示為:
其中, , ,… ,是任意的,獨(dú)立的基體。 h是該損毀鋼絲的一維特征向量,預(yù)計(jì)在三維收縮后將取得。因此,只要找到適當(dāng)?shù)膖, h可以得出:
根據(jù)該L-K轉(zhuǎn)換的原則, 當(dāng)t值為是協(xié)方差矩陣的Z的潛在的基體,是轉(zhuǎn)型錯(cuò)誤最低一個(gè)情況,即:t滿足特征方程:
其中,是的特征值,I是一單位矩陣。由公式( 8)所代替,損壞鋼絲的 期望的特征向量h可以通過三維收縮得到。 這個(gè)三維收縮的轉(zhuǎn)變過程,實(shí)際上就是一個(gè)從一個(gè)N維特征向量向一個(gè)維向量的轉(zhuǎn)換。平均一維空間h序列被視為一個(gè)特征向量代表N通道斷絲信號(hào)的每個(gè)狀態(tài):
5 結(jié)論
我們對(duì)鋼絲繩中損毀的鋼絲的檢測(cè)是一個(gè)定量檢測(cè)方法。它將不只是確定否有鋼絲損毀,也將確定損毀鋼絲的位置和數(shù)目。 結(jié)合傳感器檢測(cè)技術(shù)及計(jì)算機(jī)技術(shù)和使用先進(jìn)的信號(hào)處理技術(shù),我們可以有效地提高檢測(cè)裝置的精度和靈敏度,從而實(shí)現(xiàn)檢測(cè)設(shè)備的自動(dòng)化和智能化。
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