3D shape measurement for mechanical parts based on the wavelet and neural network in neuro-vision system 1

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1 D hpe meuremet or mechicl prt bed o the wvelet d eurl etwork i euro-viio ytem ige iog Viio Iterce & Sy. Lb. VISLb CSE Dept.Wright Stte U. OH 4545 ABSTRACT I thi pper ew o-lie meuremet d ccurcy lyi method or prt coigurtio d urce i preeted by combiig computer viio d eurl etwork. Dieret rom covetiol cotct meuremet it i o-cotct meuremet method d it c operte o-lie. I thi method the D coigurtio d urce o prt re recotructed rom tereo imge pir tke by computer viio ytem. The rchitecture or prllel implemettio o prt meuremet ytem i developed uig eurl etwork. Severl relevt pproche icludig ytem clibrtio tereo mtchig d D recotructio re cotructed uig eurl etwork. Ited o covetiol ytem clibrtio method tht eed complicted itertio clcultio proce the ew ytem clibrtio pproch i preeted uig B eurl etwork. The D coordite o prt urce re obtied rom D poit o imge by everl B eurl etwork. Bed o the bove rchitecture d the pproche the prt meuremet d ccurcy lyi ytem or itelliget mucturig i developed by mkig ll ue o the dvtge o eurl etwork. The experimet d pplictio reerch or thi ytem i lo preeted i thi pper. It i proved through the ctul pplictio tht the method preeted i thi pper c meet the eed o o-lie meuremet or prt i itelliget mucturig. It h importt vlue epecilly or o-lie meuremet o prt tht hve complicted urce. Keyword: eurl etwork o-lie meuremet computer viio D recotructio. INTRODUCTION It i very importt proce or prt meuremet d ccurcy lyi olie durig moder idutril mucturig. Uully the cotct meuremet i ued or meurig obect. Three dimeiol coordite meure d ler meure re ccurte wy to meure obect. But there re ome didvtge i thee method. For exmple ome poit tht re hdowed by other prt or c ot be cotcted by probe re meured diiculty. Thee method c oly meure ome poit o prt urce. It i very diiculty to meure the whole urce d to relize meuremet o-lie. Durig moder idutril mucturig it i required to meure prt o-lie. A the developmet o computer ciece the pplictio o computer viio techique re widely. Stereo viio c extrct D iormtio rom tereo imge pir tke rom obect d recotruct i D coigurtio []-[]. However the origil dt obtied by tereo viio re rom imge tke rom obect. I order to extrct D iormtio gret mout dt mut be proceed. It will iluece proce peed directly. A i other ield eurl etwork c provide itelligece i the proce o extrctig D iormtio o tereo viio. The bility o lerig memory o eurl etwork c reduce lrge mout o clcultio. Mive prllel proceig bility c peed D iormtio proce. I thi pper i order to meet the eed o moder idutril mucturig ew o-lie meuremet d ccurcy lyi method or prt coigurtio d urce i developed by combiig computer viio d eurl etwork. Compred with covetiol cotct meuremet thi i o-cotct meuremet method. It c operte o-lie d it h my dvtge. The D coigurtio d urce o prt re recotructed rom tereo imge pir tke by computer viio ytem. The rchitecture or prllel implemettio o prt meuremet ytem i developed uig eurl etwork. Severl relevt pproche icludig ytem clibrtio tereo mtchig d D recotructio re cotructed uig eurl etwork. Ited o covetiol ytem clibrtio method tht eed complicted itertio clcultio proce the ew ytem clibrtio pproch i preeted uig B eurl etwork. The D coordite o prt urce re obtied rom D poit o imge by everl B eurl etwork. Bed o the bove rchitecture d the pproche the prt meuremet d ccurcy lyi ytem or itelliget mucturig i developed by Thi work i upported by Gugdog rovice Nturl Sciece Foudtio o Chi uder Grt No. 7

2 mkig ll ue o the dvtge o eurl etwork. Experimet with three et o cylider re give i thi pper. The reult re very good. It i expreed tht the B eurl etwork c ler the olier reltiohip betwee two tereocopic cmer d globl coordite ytem. Actul pplictio or turbie blde re lo preeted i thi pper. It i proved through the ctul pplictio tht the method preeted i thi pper c meet the eed o o-lie meuremet or prt i itelliget mucturig. It h importt vlue epecilly or o-lie meuremet o prt tht hve complicted urce.. THREE DIMENSIONAL INFORMATION ETRACTION FOR ARTS Durig the proce o o-lie meuremet or prt the tereo imge pir re tke rom prt. Ater ome procee the D iormtio i extrcted. The D coordite o prt coigurtio re clculted rom the D iormtio. All origil dt re rom tereo imge pir. So we mut clibrte the cmer ytem irt... Cmer Clibrtio Cmer clibrtio proce i ued to determie the poitio d directio o cmer by D iormtio d it imge i the D imge. The o-lier reltiohip betwee tereocopic cmer d globl coordite ytem c be determied. So the D iormtio o prt c be extrcted by uig thi reltiohip. Covetiol pproche require elborte ytem clibrtio to determie the reltiohip [6]. Thee method re very complicted d the peed i very low. I ytem error mut be coidered the itertio procee mut be ued. So the clcultio time i very log. I thi reerch bck propgtio eurl etwork i ued. We mke ll ue o it lerig d memory bility o the eurl etwork. Through the triig mple the eurl etwork c ler the complicted reltiohip d ve it to the memory. A the cmer re ixed i the meuremet ytem thi reltiohip will ot be chged. Figure how the poitio o cmer i the o-lie meuremet ytem. Two cmer hve hred ield o view. A the ytem opertio the prt p through thi ield. Fig. Stereocopic cmer poitio Fig. plcemet o the clibrtio obect I order to clibrte the ytem et o tet obect i plced i kow loctio withi the hred ield o view o tht the cmer c tke their imge d extrct relted iormtio. Figure how the plcemet o the tet obect withi the ield o view o the cmer. Sixtee tet obect re ued t time o they c be eily plced withi the ield o view o both cmer. A the loctio d dimeio o tet obect re kow. The eurl etwork c proce them eily. I order to crete the o-lier reltiohip betwee tereocopic cmer d globl coordite ytem eurl etwork i ued to ler thi complicted reltiohip. The rchitecture the eurl etwork i how Figure. The cmer clibrte bck propgtio eurl etwork h our lyer. The iput lyer h our euro or the x d y vlue o the mtched poit o the let imge d right imge i tereo imge pir. The etwork Fig. eurl etwork or ytem clibrtio

3 h two hidde lyer. Ech o the hidde lyer coti 5 euro or torig the complicted reltiohip betwee D imge d D pce. The output lyer h three euro or d world coordite o obect... Stereo mtchig with wvelet lyi.. D wvelet lyi The D wvelet trorm o the uctio x y L R T Ψ with give mother wvelet Ψ i deied by u v x y Ψ u v x y = dxdy Ater dicretizig both the cle ctor d the trltio u v We c obti the dydic cle pce. = d u k v = l = with k l where deote the et o iteger. Let D deote the dierece betwee two pproximtio A d A D where A i idetity opertor. = A A = A i the pproximtio o give uctio x y t cle = =. There re three compoet or the dierece betwee two pproximtio A d A D = A A = D D D 4 o the multireolutio lyi o uctio x y c be writte x y = A = A = A D D = D D [ D D D D D D ] D D o 5 Give dicrete imge x y with limited upport wvelet pyrmid ivolve computig the coeiciet A D p = p o ech level. x y m d = the ctul procedure or cotructig the k l p k l which c be grouped ito our mtrice

4 A = D = d or k l p p k l k l = 6 Let h d g be the impule repoe o the ilter φ d ψ the coeiciet k l d d p k l p = c be computed vi itertive procedure. The wvelet pyrmid o imge x y d it cotructig proce re illutrted i igure 4 d igure 5. Fig. 4. Wvelet pyrmid o imge x y Fig. 5. The lowchrt or the lyi rom level to level.. Imge mtchig with globl optimiztio Stereo mtchig proce i to id correpodece betwee let imge d right imge i tereo imge pir. For y imge poit k l o the reerece imge it pproximte correpodece k l o the mtched imge my be obtied through ome geerl trtegie uch the pirl d hierrchicl prllx propgtio. The implet wy to ctch the precie correpodece k i the dicrete erch i mll eighborhood o k l which i deied by ditce threhold T r mi k S k l k k : k k T r 7 The ditce threhold Tr hould be deied i uch wy tht the llowed error i the prllx propgted rom the lt higher level c be corrected. I geerl T r. Note tht the erch tke plce ot oly o orml iteger poitio but lo o digol poitio. The computtiol tructure d the dt low o wvelet rme proceig or tereo mtchig i how i igure 6.

5 .. Three Dimeiol oit o rt Coigurtio Clcultio With the reltiohip betwee cmer d globl coordite ytem creted by ytem clibrtio proce the D poit c be clculted rom D poit o tereo imge pre. Uully the collier coditio equtio re ued [5] = = c b c b y c b c b x 8 Fig. 6. The computtiol tructure d the dt low

6 where re globl coordite o poit o obect; re the globl coordite o cmer; bi ci i = i the ocu o cmer; x y re the coordite o poit o imge i re the extriic elemet o cmer; Thee method re very complicted d the peed i very low. I ytem error mut be coidered the itertio procee mut be ued. So the clcultio time i very log. I thi reerch bck propgtio eurl etwork i ued. We c cotruct our lyer bck propgtio eurl etwork to perorm the opertio. The iput lyer h our euro or x d y vlue o the mtched poit o the let d right imge o tereo imge pir. The etwork h two hidde lyer. Ech coti 5 euro or torig the complex reltiohip betwee D imge d D pce. The output lyer h euro or the D poit. The rchitecture o B eurl etwork i how igure. By eedig the mtched poit ito the iput lyer the eurl etwork c output the D poit o the obect. I multiple etwork re vilble poit c be coverted i rllel. I order to obti the whole urce o the obect we c utilize the techique o viul urce iterpoltio [5].. THE MEASUREMENT AND ACCURAC ANALSIS FOR ART CONFIGURATION A exmple o ctul pplictio the o-lie meuremet method preeted i thi pper i ued i turbie blde mucturig proce. With thi method the D coordite re clculted. A the other blde turbie blde h irregulr urce. It i very diicult or D coordite meurer to meure the poit o the urce d it i very diicult to meure the whole urce. Here we ue the o-lie meuremet ytem preeted i thi pper to do it. Firt the ytem i teted o cylider locted i the me poitio the triig et. Three et o tet cylider re ued to clibrte the ytem Through the ytem clibrtio procee the o-lier reltiohip betwee tereocopic cmer d globl coordite ytem c be creted. The reult expected were very good. Tble to how the reult obtied with the 45mm mm d 5mm clibrtio cylider repectively. All meuremet re give i millimeter. The reult demotrte tht the eurl etwork could ler the reltiohip betwee tereocopic cmer d globl coordite ytem. Durig ytem evlutio two et o error were clculted. Thee error re RMS error or ech poit teted d the RMS o the etire tet ru. The clcultio were mde with the ollowig ormul. Where e = 9 R e = I e e re the ctul poit i globl coordite; re the poit etimted by eurl etwork; e i the poit error rom the ith poit i the tet ru; I i the umber o poit i the tet ru The ccurcy o the etwork i good coiderig the reltively ew clibrtio cylider ued or the re. The ccurcy hould be improved by uig more clibrtio poit to tri the etwork. ei Tble. Clibrtio ccurcy o 45 mm cylider e let 45imge b right imge.9 6 Fig tereo.997 imge pir o turbie blde I

7 Tble. Clibrtio ccurcy o mm cylider e Tble 4. Meuremet ccurcy o turbie blde I Clcultio reult Meuremet reult Error % x y z x y z x y z Tble. Clibrtio ccurcy o 5 mm cylider e Tble 5. Meuremet ccurcy o turbie blde II Clcultio reult Meuremet dt Error % x y z x y z x y z Figure 7 how the tereo imge pir o turbie blde I tke by tereocopic cmer o meuremet ytem. Some lbel re et o the turbie blde o tht it i coveiet or D coordite meurer to obti thee poit coordite. We c compre reult clculted rom o-lie meuremet ytem with the dt rom D coordite meurer. Figure 7 how thee poit. Firt the correpodece o let imge d right imge i tereo imge pir c be oud by tereo mtchig proce.

8 With the reult o tereo mtchig or the poit D coordite o the poit c be obtied by the method preeted i thi pper. Metime the poit re lo meured by D coordite meurer The rdiu o probe i.745l mm. Tble 4 how the reult. Tble 5 how tht the mximum error or coordite re.775% the mximum error or coordite i.75% d the mximum error or coordite i.767%. let imge right imge Fig. 7 tereo imge pir o turbie blde I I the me wy turbie blde II how i igure 8 i meured. The D poit re clculted with the tereo imge pir o turbie blde II. Tble 5 how the reult. The mximum error or coordite re.67% the mximum error or coordite i.54 % d the mximum error or coordite i.449%. let imge right imge Fig. 8 tereo imge pir o turbie blde II. CONCLUSION I order to meet the eed o moder idutril mucturig ew o-lie meuremet d ccurcy lyi method or prt coigurtio d urce i preeted. The tereo imge pir o prt i tke by tereocopic cmer mouted o the mucturig lie. Ater ome proceig or the tereo imge pir D iormtio i extrcted or prt coigurtio urce. So the D coordite o poit o the urce re clculted. Dieret rom covetiol cotct meuremet it i o-cotct meuremet method. By comprio thi method h ome dvtge tht it c obti the whole urce o the prt d c operte o-lie. The rchitecture or prllel implemettio o prt meuremet ytem i developed uig eurl etwork. Bed o the bove rchitecture d the pproche the prt meuremet d ccurcy lyi ytem or itelliget mucturig i developed by mkig ll ue o the dvtge o eurl etwork. The experimet d pplictio reerch or thi ytem i lo preeted i thi pper. It i proved through the ctul pplictio tht the method preeted i thi pper c meet the eed o o-lie meuremet or prt i itelliget mucturig. It h importt vlue epecilly or o-lie meuremet o prt tht hve complicted urce. REFERENCES. N. G. Kigbury A Dul-Tree Complex Wvelet Trorm with improved orthogolity d ymmetry propertie roc. IEEE Co. o Imge roceig Vcouver September -.. Stereo D. Cochr d Gerrd Medio -D Surce Decriptio rom Bioculr Stereo IEEE Trctio o tter Alyi d Mchie Itelligece Vol. 4 No. pp98~994 October 99.. Ruud M. Bolle Bb C. Vemuri O Three Dimeiol Surce Recotructio Method IEEE Trctio o tter Alyi d Mchie itelligece Vol.No. pp~. 4. ige iog Gugzho hg New D recotructio Approch or Itelliget Aembly Viio Sytem ACTA Scietirum Nturlium Uiveritti Suytei Vol.6 No. pp48~5 My ul S.. Wu iog ige Lerig Mechim or rt Recotructio i Itelliget Aembly Sytem The Itertiol Jourl o Advced Mucturig Techology Vol. No.6 July ige iog i Qio d Dezog Wg The Meuremet d Three Dimeiol Recotructio or Aircrt Uig Imge roceig Techique Trctio o Nig Uiverity o Aeroutic & Atroutic Vol. No. pp6~9 December Lig-Lig Wg d We-Hig Ti Cmer Clibrtio by Vihig Lie or -D Computer Viio IEEE Trctio o tter Alyi d Mchie Itelligece Vol. No4 pp7~76 April 99.