The Design and Implementation of Photoelectric Sensor for Yarn Color Fault Detection

Transcription

1 PPE THE DESGN ND MPLEMENTTON OF PHOTOELET SENSO FO YN OLO FULT DETETON The Desgn and mplementaton o Photoelectrc Sensor or Yarn olor Fault Detecton SHENG Fenhua, HEN Zujue 2 Suzhou college o normaton Technology, hna; 2 Jangx Unversty, hna bstract The paper manly amed at solvng the problem o yarn color ault detecton. Yarn wth derent color s hard to detect n yarn producton, a specal photoelectrc sensor s desgned n ths paper. Frst, ths paper analyzed the requrement o lght source and photoelectrc recever n the photoelectrc sensor, and desgns the lght path and drver crcut. Then ths paper analyzed the ampler crcut and nose n the photoelectrc sensor, wth an ampler crcut o mnmal nose proposed at last. Fnally, ths paper tested the yarn color ault detecton system wth vrtual nstrument, and the test results showed a great applcaton prospect o the photoelectrc sensor. Photoelectrc yarn clearer was the rst type o electronc yarn clearer, but due to the under development o the optcal technology and measurement technology, the photoelectrc yarn cleaner can't meet the requrements o textle producton, gradually replaced by capactve yarn cleaner. Though photoelectrc yarn cleaner had a good vsual conormty degree, t s stll a unreplaceable method n colored yarn aults []. ndex Terms Photoelectrc Sensor, Yarn, olor, Fault Detecton. NTODUTON. Desgn o Photoelectrc Sensor Ths paper desgned a photoelectrc sensor module to solve the problem. The module s shown n Fgure. change o the yarn. Parts o the lght come rom the lght source wll be blocked by the yarn, the let parts wll receved by the through beam recever. The larger the yarn's dameter, the lesser lumnous ntensty the through beam recever wll receve. The through beam recever am to get the yarn's dameter normaton, n a consequence o dsmss relatonshp o relectve beam and the yarn's dameter normaton. The components selecton and optcal path desgn o the photoelectrc sensor s descrbed below. B. Lght Source Due to the restrcton o electronc yarn cleaner's sze, the lght source should be as small as possble, whle the lght source keep a hgh brghtness. The color normaton detect rom the yarn not only related to the relectve beam, also has a relatonshp to the spectrum o lght source. Ths paper am to detect the yarn's color ault among the vsble spectrum, thus the lght source must contan the entre vsble spectrum. To sum up, ths paper chooses the hgh brghtness whte LED as lght source o photoelectrc sensor. Ths whte LED used n ths paper s made o ndum gallum ntrde (ngan) chps and yttrum alumnum garnet (YG) phosphor. The peak o ngan chp s 465nm blue lght, ths blue lght excte the YG phosphor to emt yellow lght peak at 550nm. Parts o the blue lght emt rom the chp absorbed by the YG phosphor, the let parts mxed wth the yellow lght become the whte lght. The spectrum o the wht lght s shown n Fgure 2, among the vsble spectrum, the whte lght s brghtness o sngle LED s above cd, wth color temperature o 6500k, and a renderng ndex greater than 70. The whte lght LED has the qualty o stablty and hgh brghtness, sutable or the detecton o yarn color aults. Fgure. The photoelectrc sensor module Photoelectrc sensor conssts wth the lght source, relectve beam recever and through beam recever[2, 3]. When the lght source emts lght on the yarn, some wll be absorbed and some wll relect. The relectve beam not only contans the yarn's color (gray) normaton, but also the yarn's dameter normaton. The relectve beam receved by relectve beam recever. When the color or dameter o the yarn changes, the relectve beam's lumnous ntensty wll also change. n order to get the color normaton, the dameter normaton must be removed, so the through beam recever s added. The change n through beam recever s dependng on the dameter Fgure 2. Spectrum o the Whte LED JOE Volume 2, ssue 2, 206 5

2 PPE THE DESGN ND MPLEMENTTON OF PHOTOELET SENSO FO YN OLO FULT DETETON. Photoelectrc ecever There are a lot o knds o photoelectrc detecton devce, such as: phototube, photomultpler tubes, photocell, photoelectrc dode, and photoelectrc trode, etc. n ths paper, due to the restrcton o the photoelectrc devce's sze, some o the devces can't be selected, such as phototube, photomultpler tubes, photo cell. lso the speed o the yarn can get up to 20m/s, thus the photoelectrc detecton devce must have a good dynamc characterstcs. To sum up, ths paper chooses the dode as the photo electrc recever. The dode also has the advantages o stablty, hgh senstvty and low prce. Ths paper selects the photoelectrc dode manuactured by Bejng's north optoelectronc co., LTD, model 2cu2e. The dode has 400 nm to 00 nm spectral range, peak at 800 nm, maxmum workng reverse voltage o 50v, maxmum dark current less than 0.u. The dode under 000Lx ntensty, 2856k juncton temperature lght, has the lght current up to 40u, and the response tme s hgher than 200ns. The characterstc o the dode descrbed above t the requrements o ths paper. D. Lght Path The detecton theory o the photoelectrc sensor s shown n Fgure 3. Fgure 3. Detecton Theory o Photo electronc sensor s shown n gure 3, when the yarn go through the detecton area o the photo electronc sensor, the relectve beam recever and through beam recever wll both receve a lare whch wll change wth the yarn's dameter and color, the recever wll get the normaton o the yarn's dameter and color. The method descrbed above requre the lght to be collmated, and at same ntensty. LED s a pont lght source, the lght emt rom t n radaton at certan angle. To make the lght parallel to each other, the collmaton lght path s added to the photo electronc sensor, shown n Fgure 4. path determne the aperture angle o the system, also sets the resoluton and contrast. Kohler llumnaton can generate parallel lght, make the measured ntensty o llumnaton unormty, ths process make sure all parts o the yarn can be detected and dented. Ths paper select the 4mm Kohler lens, wth ocal length o 2mm, the convex lens' dameter s 4mm wth 2mm ocal length. Meanwhle, n the yarn ault detecton, the dode must receve as much as lght as possble, or all the lght goes to the recever must cover the dode's photosenstve surace as much as possble, so a condenser lens s added beore the dode, shown n Fgure 5. The condenser lens has a dameter o 5mm, a ocal length o 2mm. Fgure 5. The ondenser Lght Path o Photoelectrc Dode. DESGN OF THE LGHT SOUE DVNG UT ND SGNL POESSNG UT The method o photoelectrc yarn law detecton belongs to the weak lght detecton, lght ntensty change caused by yarn ault s very small, thus ts requrements on the stablty o lght source s very rgd. n addton to materals o LED tsel, the lght source's lumnous stablty s manly decded by the LED lght drver crcut. n ths paper, ater consderng varous LED lght drver crcut, decde to adopt the LED constant current drver crcut. Drver crcut s shown n Fgure 6 Fgure 6. onstant urrent Drver rcut. Fgure 4. LED collmaton lght path LED collmaton lght path use the method o Kohler llumnaton to get unorm parallel lght. Kohler lens zoom up the lght emt rom the lght source, put lght n ront o the convex lens' ocal plane, and the eld stop also at the convex lens' ocal plane, the convex lens magng the lght n nnte dstance. The aperture n the lght Ths crcut uses the voltage controlled current source, whch s a mproved Howland current pump, and t can provde photoelectrc dode wth constant drve current. ompared wth the swtchng PWM crcut, ths crcut has a better lnearty, whch can eectvely reduce the drve current rpple. Output current out s controlled by V nput voltage n, the nput voltage s generated by sys- 6

3 PPE THE DESGN ND MPLEMENTTON OF PHOTOELET SENSO FO YN OLO FULT DETETON tem chp, the relatonshp between output current out V and nput voltage n s: out V n 4!, 3 s Whch n the crcut, select OP350 o T company as op-amp. OP350 s - MOS operatonal ampler, the bandwdth s up to 38 MHZ, pressure swng rate s 22 v/us, the op-amp has a hgh swtchng speed, low nose. n order to meet the crcut requrements, Set equaton, V n () 00K!, 4 0K!, 0! /00 out 30m 3 s 3V out V n, set, orm, then. The smulaton result s shown n Fgure 7. Fgure 7. onstant urrent Drver rcut Smulaton esult. TNSESSTNE MPLFE The detecton o the photoelectrc current o the photoelectrc dode s crucal to the sgnal processng. Because o the photoelectrc current sgnal s very weak, the desgn o the pre-ampler s partcularly mportant. Those should be consdered, such as nose and senstvty and response tme. The nose aects the detecton o the photoelectrc current most. compensaton. The nternal nose, such as dark current nose, thermal nose, ampler nose, can t completely elmnated but only can reduce them as much as possble through crcut desgn[4]. The ampler can amply the sgnal as much as possble, but at the same tme, the nose s also beng ampled, the detected photoelectrc sgnal s too weak, s lkely to be covered up by the nose. Fgure 9. Transresstance mpler esponse tme reers to the tme o crcut rom recevng a mutaton sgnal to a stable state. Ths paper adopted the LED drve sgnal o 25KHz square wave modulaton sgnal, requre a ast response speed o the crcut. Ths paper use transresstance amplers to amply the prmary sgnal o the photoelectrc dode. The structure o the transresstance amplyer s shown n Fgure 9. Transresstance amplers use a resstor wth hgh resstance as eedback, has the characterstc o hgh gan and hgh mpedance, at the same tme, the transresstance has low nose, large bandwdth and wde dynamc range, commonly used n crcut wth requrements o speed. Fgure 0. Transresstance mpler Equvalent Model s shown n gure 0 s the transresstance amplers equvalent model, the photoelectrc dode can be equvalent to a constant current source p, wth paralleled connecton o a large resstance and a small capactance Fgure 8. Nose n the Photoelectrc Sgnal mplyng rcut Photoelectrc sgnal s very weak, n the process o transmsson, detecton, and amplcaton, t wll always be nterered by varous nevtable actors. The nose ntroduced n the process o photoelectrc sgnal amplyng s shown n the gure 8. The quantum nose rom the surroundng space and envronment, the electrcal magnetc ntererence rom the surroundng electronc equpment can be prevented through such as sheldng and groundng. The ambent lght ntererence can be elmnated through. n the crcut,, respectvely, as the ampler's nput resstance and nput capactance. Set operatonal ampler as deal, as the eedback resstance, then the transer uncton o the crcut s: V! " H! 0( ) p (!) j! (2) JOE Volume 2, ssue 2, 206 7

4 PPE THE DESGN ND MPLEMENTTON OF PHOTOELET SENSO FO YN OLO FULT DETETON n general ntermedate requency o operatonal ampler gan!!, and the equvalent resstance o photoelectrc dode!! V! H! 0( ) (!), then, equaton (2) s: " " j! p + j! + The transresstance s bandwdth s smlar to:! 0 (4)! 0, then the operatonal ampler tend to be more open. Transer uncton or ths tme s: H! The bandwdth s:! " + j! (6) " + j!! "" From equaton (4) and (6), the, meanng the transmpedance ampler bandwdth s bgger than no eedback ampler bandwdth, compared wth a hgh mpedance ampler, transmpedance ampler bandwdth broadenng tmes, and s proportonal to the ampler s gan, and s nversely proportonal to the eedback re- 0! (3) (5) s up to 24MHz. Pressure swng at a rate o whch can guarantee a wde response speed; the nput bas current s p, whch can eectvely reduce the nose rom the op-amp. and are resstance and capactance compensatons. s eedback capactance, used to oset the photoelectrc dode juncton capactance nluence on subsequent crcut, and prevent the amplyng crcut sel-excted vbraton oscllaton, and are decder n transresstance amplers n the crcut perormance, they wll aect the requency stablty and the nose perormance o detecton crcut. n practcal applcatons, the M!,. 5pF V. SGNL QUSTON ND POESSNG BSED ON VTUL NSTUMENT Base on the desgn progress and analyss above, the yarn ault detecton system manly want to collect data o 25KHz square wave, and the N company s P-625 hgh precson data acquston board s well t to our purpose[5]. nd wth N-DQmx drver and Measurement &utomaton Explorer (MX) sotware, combned wth Labvew, the acquston data o relectve beam normaton and through beam normaton wll save to.xcl le ater the experment. The experment set up wth two derent dameter o unorm whte yarn producton as yarn gauge, rovng lne dameter s about 0.2mm, spnnng lne dameter about 0.08mm n dameter. Dye the yarn o derent thckness separately wth green, yellow, black and orange, as derent yarn color aults. Testng or each color, save the tests data, then use Matlab to de-nosng. Due to the lmtaton o expermental condtons, ths paper only conduct the experment to test the system s statc perormance. The results s shown n Fgure 2 and 3 n below.. sstance. educe can ncrease the bandwdth o the ampler, lower the nose. nd by reducng, the response speed o the photoelectrc senor also mproved. To sum up the above analyss, ths paper adopts the crcut as below: Fgure 2. Derent dameter o yarn wth red color ault Fgure. dopted Transresstance mpler rcut The operatonal ampler chose the precson low nose op-amp D866 o D company. The bandwdth product 2 V/ µ s, Fgure 3. Derent dameter o yarn wth black color ault 8

5 PPE THE DESGN ND MPLEMENTTON OF PHOTOELET SENSO FO YN OLO FULT DETETON s shown n Fgure 2 to 3, derent thcknesses on red yarn deects and black yarn yarn deects sgnal n contrast, sgnal s larger or the test results o rovng lne, small sgnal or the test results o spnnng lne, yarn dameter changes has a clear mpact on the detecton sgnal, the larger the dameter o the yarn, the more obvous eect on lght relecton. V. ONLUSON The expermental results show that the desgn o photoelectrc sensor can be eectvely detected yarn o derent color ault. esults also show that the relecton endng o the photoelectrc sensor at the same tme, n addton to the derent color yarn deects on the yarn can be eectvely detect, ts detecton sgnal s senstve to changes n yarn dameter. n the practcal work, we hope that relex photoelectrc sensor output sgnal at the recevng end s only related to the derent color yarn aults, not the dameter and the relevant department. So n the desgn o photoelectrc sensor, we joned the photoelectrc transmsson and the recevng end, to measure the dameter o the yarn normaton as a compensaton sgnal due to the yarn dameter changes eect the output sgnal. The vrtual nstrument experment result testes that the photoelectrc sensor and the method proposed n ths paper to detect yarn ault s both vald and ecent. EFEENES [] Yadav, V. K., Josh, S. D., shtaque, S. M., & hatterjee, J. K Yarn ault classcaton: a sgnal processng approach usng multple projectons. Journal o the Textle nsttute, -9. [2] Gonçalves, N., arvalho, V., Belsley, M., Vasconcelos,. M., Soares, F. O., & Machado, J Yarn eatures extracton usng mage processng and computer vson study wth cotton and polyester yarns. Measurement, 68, j.measurement [3] Sengupta,., oy, S., & Sengupta, S Development o a low cost yarn parametersaton unt by mage processng. Measurement, 59, surement [4] uru, Z., & Xao, G The pplcaton and Development o Photoelectrc Sensor. Energy Proceda, 7, [5] Zukovc, S., Medenca, M., Draganc,., Orovc,., & Stankovc, S Vrtual nstrument or ompressve Sensng o multmeda sgnals. n ELM (ELM), th nternatonal Symposum (pp. -4). EEE UTHOS SHENG Fenhua s wth Suzhou college o normaton Technology, Wujang Suzhou, Jangsu, O25200, hna HEN Zujue s wth School o omputer Scence and Telecommuncaton Engneerng, Jangsu Unversty, Zhenjang, Jangsu, O22000, hna Submtted 7 September 205. Publshed as resubmtted by the authors 3 January 205. JOE Volume 2, ssue 2, 206 9