S ha bi Trung tm Hc liu - HTNhttp://www.lrc-tnu.edu.vn/ I HC THI NGUYN TRNG I HC K THUT CNG NGHIP PHM HNG NAM THIT K, CH TO THIT B O M MEN XON TRN TRC QUAY LUN VN THC S K THUT Thi Nguyn, thng 12nm 2014 S ha bi Trung tm Hc liu - HTNhttp://www.lrc-tnu.edu.vn/ --------------------000------------------- PHM HNG NAM THIT K CH TO THIT B O M MEN XON TRN TRC QUAY Chuyn ngnh: Cng ngh ch to my M s: 60520103 LUN VN THC S K THUT Thi Nguyn, thng 12nm 2014 PGS.TS Ng Nh Khoa S ha bi Trung tm Hc liu - HTNhttp://www.lrc-tnu.edu.vn/ LI CAM OAN Tn ti l: Phm Hng Nam Sinh ngy: 01 thng 3 nm 1981 Ni sinh: Thnh ph Thi Nguyn, tnh Thi Nguyn Hc vin lp cao hc kha K14-chuyn ngnh: Cng ngh ch to my- Trng i hc k thut cng nghip Thi Nguyn Hin ang cng tc ti S Cng Thng Thi Nguyn. Ti xincam oan nhngkt quc ctronglun vn l do bn thn ti thc hin di s hng dn ca thy gioPGS.TSNg Nh Khoa.Ngoi phnti liu tham kho c lit k, cc kt qu v s liu thc nghim l do ti thc hin v cha c cng b trong bt c cng trnh no khc. Tixincamoanrngmithngtintrdntronglunvnuchr ngun gc. Thi Nguyn, thng 12 nm 2014 Ngi thc hin Phm Hng Nam S ha bi Trung tm Hc liu - HTNhttp://www.lrc-tnu.edu.vn/ MC LC BNG DANH MC CC HNH V.................................................................................. 5 PHN M U .................................................................................................................. 7 1. Tnh cp thit ca ti .................................................................................................... 7 2. Mc ch nghin cu ti .............................................................................................. 7 3. i tng nghin cu ca ti ....................................................................................... 7 4. ngha khoa hc ca ti ............................................................................................. 7 5. Phng php nghin cu .................................................................................................. 8 CHNG I. TNG QUAN V THIT B O M MEN XON .................................... 9 TRN TRC QUAY ........................................................................................................... 9 1. Gii thiu v thit b o m men xon trn trc quay ...................................................... 9 2. Nguyn l c bn o m men xon trn trc quay ......................................................... 12 3. La chn phng n thit k .......................................................................................... 14 CHNG 2. C S TNH TON THIT K TRC QUAY ........................................ 17 I. Phn tch yu cu bi ton: .............................................................................................. 17 1. Mc ch ca ti ......................................................................................................... 17 2La chn kiu trc quay ................................................................................................. 17 3. Phn tch bi ton ........................................................................................................... 18 II. CM BIN BIN DNG (STRAIN GAUGE) ............................................................... 19 1. Cu to strain gauge ....................................................................................................... 19 2) Phn loi strain gauge .................................................................................................... 20 3) Thng s c bn v cc c trng ca strain gauge ....................................................... 21 CHNG 3. THIT K, CHTO THIT B O M MEN XON ......................... 23 I. Thit k trc chu xon (trc quay) ................................................................................. 23 1. Chc nng: ...................................................................................................................... 23 2. Tnh ton thit k trc ..................................................................................................... 23 3) Bn v thit k trc quay ................................................................................................ 26 II. Nghin cu la chn strain gauge ................................................................................. 26 III.ng dng mch cu Wheatstone trong vic bin iR ca strain gauge thnh in p ................................................................................................................................. 28 IV. La chn b khuych i, b x l, ngun v mn hnh hin th ................................ 33 1. La chn b khuych i................................................................................................ 33 2. La chn h thng x l d liu ..................................................................................... 35 3. Mn hnh hin th ............................................................................................................ 36 4. Ngun cp in p .......................................................................................................... 38 S ha bi Trung tm Hc liu - HTNhttp://www.lrc-tnu.edu.vn/ V. Tin hnh dn strain gauge ............................................................................................ 40 1. Chun b vt t, dng c ................................................................................................. 40 2. Cc bc tin hnh dn strain gauge .............................................................................. 41 CHNG 4. XC NHC TNH LM VIC CA THIT B BNG THC NGHIM ............................................................................................................................ 46 I. Thit k s th nghim ................................................................................................ 46 1. Mc ch: ........................................................................................................................ 46 2. M hnh th nghim ........................................................................................................ 46 3. Thit b th nghim ......................................................................................................... 46 II. Kt qu th nghim ......................................................................................................... 47 1. Th nghim kho st gi tr in p hin th khi t ti trng bit. ............................ 47 2. Thnghim o m men xon trn trc quay. ................................................................ 48 3. nh gi kt qu v nhn xt .......................................................................................... 49 4. Kt lun v hng nghin cu tip theo ......................................................................... 49 5. Mt s hnh nh ca thit b ........................................................................................... 50 6. Chng trnh ci t cho b x l ardunio ..................................................................... 53 TI LIU THAM KHO .................................................................................................. 57 S ha bi Trung tm Hc liu - HTNhttp://www.lrc-tnu.edu.vn/ BNG DANH MC CC HNH V Hnh 1.1: C l lc Tohnichi FHDS Hnh 1.2: Tua vt lc STC (TOHNICHI) Hnh 1.3:Dng c o m men o lc ng, m chai.Hnh1.4lthitbommenxonloiST2-BTspintorkcahngExcelAirtool co.,INC Hnh 1.5: ng dng thit b o m men xon loi ST2-BT spin tork trong lp rp. Hnh 1.6a: Cm bin m men xon kiu 4503 A ca hng Kitsler Hnh 1.6b: ng dng cm bin m men xon trong vic kim tra ng c Hnh 1.6c: Cu to cm bin m men xon kiu 4503 A ca hng Kitsler Hnh 1.6d: S ca nguyn l hot ng ca cm bin m men xon. Hnh 1.7: S h nguyn l cm bin o m men xon dng vnh gp Hnh 1.8: Hnh nh tho ri cm bin m men xon dng vnh gp slip ring Hnh 1.9:S h nguyn l cm bin o m men xon dng bin p quay Hnh 1.10: Nguyn l c bn ca cun dy bn trong Hnh 1.11: Hnh v cu to bn trong ca cm bin m men xon dng bin p quay Hnh 1.12. Hnh v cu to thit b o m men xon dng strain gauge tch hp vi h thng chuyn i , b lu tr d liu v hin th gn trn trc quay.Hnh 1.13.Hnh v cu to thit b o m men xon dng strain gauge tch hp vi h thng chuyn i , b lu tr d liu v hin th gn trn trc quay. Hnh 2.1: Hnh v kt cu mt s trc quay thng gp Hnh2.2: M hnh bi ton Hnh 2.3: M t lc tc dng v bin dng ca dy dn Hnh 2.4: Cu to mt strain gaugse in hnh Hnh 3.1: Bn v hnh dng v cc k hiu kch thc trn trc quay Hnh 3.2: Hnh biu din lc tc dng ln mt bch ca trc quay Hnh 3.3. Bn v thit k chi tit trc quay.Hnh 3.4: Phng n dn strain gauge ln trc quay. Hnh3.5: Bng thng s v hnh dng strain gauge kiu Z23-FA-2-350-11 Hnh 3.6: Mch cu Wheatstone Hnh 3.7: Quarter-Bridge Hnh 3.8 : S dng dummy gauge trnh nh hng ca nhit Hnh 3.9: nh hng ca in tr dy dn mch o dng Quarter-Brige Hnh 3.10: Half-BridgeHnh 3.12: S nguyn l ca cu 6 dy Hnh 3.13: S khi chc nng ca IC 3B18 Hnh 3.14 : kt ni u vo 3B18Hnh 3.15. Bng m t chn chc nng Hnh 3.17: Ty chnh h s khuych i Hnh 3.18. Hnh nh cu to b vi x l andunio S ha bi Trung tm Hc liu - HTNhttp://www.lrc-tnu.edu.vn/ Hnh 3.19. S mch led 7 on\ Hnh 3.20: S khi mn hnh hin th Hnh 3.21: S mch ngun Hnh 3.22: Keo dn Extra 4000-Showa v bng dnh Scotch Hnh 3.23. nh trc mu sau khi gn strain gauge. Hnh 3.24. Hnh nh kim tra nhy xon ca thit b sau khi dn strain gauge bng mn hnh hin tr Daytronic 3570. Hnh 3.25. Hnh nh thit b o m men xon do hc vin thit k, ch to Hnh 3.26. Hnh nh kt ni thnh cng strain gauge vi b ngun, b khuych i, vi x l v mn hnh hin th Hnh3.27.Hnhnhlptthitbommenxontrntrucquaylnbtruyn ng to m men xonHnh 3.28. th biu din kt qu o m men hin th qua gi tr in p V0Hnh 4.3. Hnh nh kim tra nhy xon ca thit b sau khi dn strain gauge bng mn hnh hin tr Daytronic 3570. S ha bi Trung tm Hc liu - HTNhttp://www.lrc-tnu.edu.vn/ PHN M U 1. Tnh cp thit ca ti Ngy nay vi s pht trin ca khoa hc, cng ngh. Dng c o lng c nhng bc tin ln v cht lng, kt cu v s thun tin khi s dng. C th nhv chnh xc php o, phng php o, cch hin th kt qu o, kh nng tch hp vi my in, my vi tnh, kh nng thu pht khng dy. Thit b o lng thng c phn thnh cc nhm nh: o lng nhit, o lng p sut, o lng lc v m men, o lng cng, o lng di, o lng cc ch tiu ha l, o dung tch, o khi lng, o bc x ht nhn Thitbommenxontrntrcquaydatrnnguynlmchcu wheatston,tnhiuuratcccmbinbindngcktnivib khuych i 3B18 ca hng Analog divices, vi x l Ardunio gim ng k cng vic tnh tonthit k c kh, tng chnh xc ca thit b. Kt qu ca ti s l c s thit k ch to cc thit b o m men xon, ng dng cc strain gauge vo cng tc o bin dng trn trc quay, la chn b khuych i v x l tn hiu o cho mch cu hai tay vmch cu 4 tay (Half- Bridge v full-Bridge). 2. Mc ch nghin cu ti Thitkchtothitbommenxontrntrcquaydio0Nm-500Nm. 3. i tng nghin cu ca ti * i tng nghin cu: - Cc loi strain gauge. -Thit k trc chu xon thun ty - Nguyn l mch cu wheatston. - K thut gn strain gauge trn trc quay, kt ni ng ra ca strain gauge vi b khuych i v b vi x l; 4. ngha khoa hc ca ti * ngha khoa hc ca ti:-Xydngvthnghimccngnghdnstraingaugetrnbmt trc chu xon bng nhm. La chn v th nghim thnh cng s dng strain gauge vi b khuych i v b vi x l; S ha bi Trung tm Hc liu - HTNhttp://www.lrc-tnu.edu.vn/ Xcnhcmul3B18khuychitnhiuinpvcngbt strain gauge c th hin th c kt qu o m men xon. * ngha thc tin:- Kt qu ca ti dng lm c s thit k ch to thit b o m men xon trn trc quay.- Sn phm ti lm dng c o mmen xon s dng trong thc hnh, th nghim ti trng i hc k thut cng nghip Thi Nguyn. 5. Phng php nghin cu Phng php nghin cu l thuyt kt hp vi nghin cu thc nghim. S ha bi Trung tm Hc liu - HTNhttp://www.lrc-tnu.edu.vn/ CHNG I. TNG QUAN V THIT B O M MEN XONTRN TRC QUAY 1. Gii thiu v thit b o m men xon trn trc quay Thit b o m men xon c s dng rng ri trong cng nghip lp rp v ch bin ch to, sa cha nh: thit b cm tay, th ng c my cng c,. a s cc thit b o m men xon ch yu c nhp khu t cc nc: M (hng Futex), Anh, n , Trung Quc... Cc thit b ny s dng phng php o bin dngtrn trcquay tnh rammenxon.Bindng trn trc quaycxcnhnhccstraingaugedntrntrcvhotngdatheo nguyn l cu in tr cn bng Wheatstone. Gia cng v ch to nhng thit b ny tng i phc tp v i hi chnh xc cao. Thitbommenxonhiuctrnthtrngcthchialm2loi: Thit b o m men xon tnh v thit b o m men xon ng. Mmenlmtlcquay,mmenxoncoiltnhnunkhngcgia tcgc.Vdnhccm-menxonsinhrabimtlxonghslmt m-men xon tnh. Tuy nhin vic xc nh m men tnh v m men ng cn ph thuc vo v tr o. V d m-men xon c sinh ra bi ng c xe t s cchailoitnh vng.Num-menxon cotrc khuuslm menng,vncdaonglndomikhinhiuliuchytrongxilanhs sinh ra lc tc dng lc ln u piston lm trc khuu quay. Nu m-men xon cocctrcnsgnnhtnhvquntnhquaycabnhvb truyn dn s lm gim mc dao ng. Cc thit b o m men xon ngy nay thng c cu to gm ccthnh phn chnh nh sau:- Trc xon c dn strain gauge v cc mt bch lp ln thit b cn o; - B khuych i tn hiu t cm bin - B x l tn hiu o, hin th kt qu - Ngun cp in; - Lp v bo v. S ha bi Trung tm Hc liu - HTNhttp://www.lrc-tnu.edu.vn/ a) Mt s thit b o m men xon tnh: Hnh 1 .1: C l lc Tohnichi FHDSHnh 1.2: Tua vt lc STC (TOHNICHI) Hnh 1.3:Dng c o m men o lc ng, m chai. , ung. Hnh 1.5: ng dng thit b o m men xon loi ST2-BT spin tork trong lp rp. Trnhnh4lthitbommenxonloi ST2-BTspintorkcahngExcelAirtool co.,INC.Hotngtheonguynlbinp quay.Sdngcmbin,truyndliubng bluetooth, thch hp vi kim tra m men xon u ra, chnh xc 1%, s dng pin cp inchoccu(10hchy/2hxc).Githam kho: Vi loi ST10N2 l 2904 USD. Hnh 1.4. S ha bi Trung tm Hc liu - HTNhttp://www.lrc-tnu.edu.vn/ b) Thit b o m men xon ng Hnh 1.6a: Cm bin m men xon kiu 4503 A ca hng Kitsler Hnh1.6b:ngdngcmbinmmenxon trong vic kim tra ng c Hnh 1.6c: Cu to cm bin m men xon kiu 4503 A ca hng Kitsler Hnh 1. 6d: S ca nguyn l hot ng ca cm bin m men xon. S ha bi Trung tm Hc liu - HTNhttp://www.lrc-tnu.edu.vn/ Cmbinmmenxonkiu4503AdohngKitslersnxuthotngda trnnguynlbinpquay.Thngcdngtrongvicgimstkimtra ng c in. 2. Nguyn l c bn o m men xon trn trc quay a) Dng strain gauge tch hp vi vnh gp (slip ring):Phng n ny thng c s dng ch to thit b o m men xon. kt ni cc strain gauge trn trc quay vi phn tnh ngi tas dngchi qutbngBc-Graphittipxcvicgp.Chiqutvcgpcnhimv a in p kch thch vo v nhn tn hiuin p ra tmch cu. Cc strain gauge c kt ni thnh mch cu wheatstone v dn trn trc xon nh s nguyn l. + u im: C li th khi s dng c c dng xoay chiu v mt chiu kch thch mch cu, hot ng vi mi tc ; + Nhc im: Tc trc quay kh cao, trong qu trnh ha ng c ma st gia chi qut vc gp nn gymn chi qut, nhiu ng, chnh xc khng cao. Hnh 1.7: S h nguyn l cm bin o m men xon dng vnh gp S ha bi Trung tm Hc liu - HTNhttp://www.lrc-tnu.edu.vn/ Hnh 1.8: Hnh nh tho ri cm bin m men xon dng vnh gp slip ring b) Dng strain gauge tch hp vi bin p quay: Phng php ny hot ng theo nguyn tccm ng truyn tn hiu in.Thitbsdng2mybinp.Mtmybinpdngtruyndng in xoay chiu (AC) kch thch cho mch cu. My bin p cn li truyn tn hiu u ra ca mch cu. Khi c in p kch thch cho cun dy s cp th t trng bin thin to ra trong mch in th cp 1 hiu in th th cp. y haimybinpthaythcho4vngtrtvchithan,trongqutrnhhot ng cng khng c s tip xc trc tip. Tn hiu c truyn qua khong cch khng kh gia cun dy s cp v cun th cp nh hnh v. uim:Tnhiunnh,chochnhxccao,botrthnsovi phng php vnh gp(slip rings). Nhc im: chnh xc ca thit b ph thucvokhongcchca2cundytrongbinp.Khchto,githnh thit b cao. ng dng: Thng c s dng cho cc c cu quay vi tc cao, cc c cu o cn chnh xc cao. S ha bi Trung tm Hc liu - HTNhttp://www.lrc-tnu.edu.vn/ Hnh 1.9:S h nguyn l cm bin o m men xon dng bin p quay Hnh1.10:Nguynlcbn ca cun dy bn trongHnh 1.11: Hnh v cu to bn trong ca cm bin m men xon dng bin p quay 3. La chn phng n thit k a) La chn phng n thit k Trncs2phngnthitkommenxontrnemnhnthy phng php dng vnh gp (slip rings) c nhiu nhc im nh nu trn. Phng php dng bin p quay c nhiu u im nhng kh ch to v i hi chnh xc cao nn khng la chn thit k. gii quyt bi ton o m men xon ph hp vi thc t ca ti tc gi xut phng n mi nh sau: Dng strain gauge tch hp vi h thng chuyn i, lu tr d liu v hin th gn trn trc quay:Phng php nyginghai phngn trnch ccstrain gauge c gn trn trc quay nhng khc l ngun nui in p cho mch cu v nhn tn S ha bi Trung tm Hc liu - HTNhttp://www.lrc-tnu.edu.vn/ hiuinptmnhcuthngquaybkhuychi.Sautnhiuinp saukhuychictruynnbxlvtruynnmnhnhhinthv lu tr d liu. Ton b cc thit b trn c gn trn trc quay. uim:ddnghiuchnh,trongccukhngcbphnchuyn ng, t nhiu ng do m bo c chnh xc ca thit b. Nhcim:Cnclpbovccthitbint,thngxuynphi np pin do phi cp ngun in p nui b hin th v lu tr d liu. Phng n dng strain gauge tch hp vi h thng chuyn i v lu tr dliu gn trn trc quay ph hp vi thc tin. Cng tc thit k, ch to trc xoncththchinngaytixngckhkhngyucuccmychuyn dng, cc thit b khuych i, b x l v b lu tr d liu c th la chn loi thch hp c bn rng ri trn th trng. Hnh1.12:Skhihthngommenxondngdngstraingaugetch hp vi h thng chuyn i b lu tr d liu v hin th gn trn trc quay STRAIN GAUGE BRIDGE B KHUYCH IB X L LU TR D LIU S ha bi Trung tm Hc liu - HTNhttp://www.lrc-tnu.edu.vn/ b) Cu to thit b Hnh 1.13. Hnh v cu to thit b o m men xon dng strain gauge tch hp vi h thng chuyn i , b lu tr d liu v hin th gn trn trc quay. Ch gii:1: Trc chu xon gn lin mt bch; 2: B chuyn i v lu tr d liu; 3: Strain gauge bridge; 4: Ngun v b x l ARDUINO. c) Phng n lp t o m men xon ommenxonthtrcscniviviccutruynmmen xonvccuhmnhmtbch2u.Ditcdngcammenxon truyn t trc ng c n hp gim tcqua trc xon v n c cu hm lm trc obin dng.Sbindng nytlvimmen.Nh vyvic xcnh c bin dng ca trc o cng chnh l xc nh mmen ca c cu. S ha bi Trung tm Hc liu - HTNhttp://www.lrc-tnu.edu.vn/ CHNG 2. C S TNH TON THIT K TRC QUAY I. Phn tch yu cu bi ton: 1. Mc ch ca ti- Thit k c thit b o mmen xon trn trc quay; Ch to c thit b th nghim. Nghin cu, la chn b khuych i, b lu tr d liu v hin th; Tin hnh th nghim phn tch, nh gi cc kh nng lm victhit b ng vn hnh n nh chnh xc ca thit b. 2La chn kiu trc quayHnhdng,ktcucamtstrcquaythnggptrongthitk,ch to thit b o m men xon theo phng php bin dng tip xc: a. Tr trn cb. Tr trn rngc.Trtrnrngcvch lm Hnh 2.1: Hnh v kt cu mt s trc quay thng gp c din tch dn cc strain gauge ln trc ta cn ng knh ngoi ca trc ln nhm to thun li cho qu trnh ch to cm bin. Trc tr c ng knh nh khng p ng yu cu t ra. Tr trn rng c vch lm s to thun licho qu trnhdnstrain gaugeln trc nhngmc bindng trn cng bn knh khng u. Dotcgilachndngtrcrngcmtcthnhvnhkhn,kiu thit k hnh b vi u im l: d ch to gia cng; chu xon tt, kch thc trc ln thun tin cho vic dn cc strain gauge ln trc.Nhc im: khng th o c gi tr m men xon thp, nhy xon km. Tuy nhin di o ca thit b nghin cu kh ln t 0 Nm n 500Nm nn c th chp nhn c. S ha bi Trung tm Hc liu - HTNhttp://www.lrc-tnu.edu.vn/ 3. Phn tch bi ton Sau khi la chn c hnh dng trc chu xon ta c bi ton nh sau: Gi s ta c trc trn c mt ct hnh vnh khnch chu xon thun ty vi m men xon M, ng knh ngoi D, ng knh trong d, chiu di trc l nh hnh v 14. Khidnstraingaugetheophng45osovingsinhcatrcchu xon theo nguyn l mch cu Wheatston. Di tc dng ca m men xon trc bin dng b ko hoc nn theo phng xin mt gc 45o so vi ng sinh. Do ng lc v bin dng c quan h vi nhau v t c th xc nh c ng lc khi o bin dng do n gy ra. Hnh2.2: M hnh bi ton ytrngthingsuttimtimtrntrctrnchuxonltrng thi trt thun tu vi 1=-3= p dng nh lut Hc v bin dng di u=E1= G 2 y ta c G= ) 1 ( 2E(1) Di tc dng ca Mz, trc chu bin dng xon trn mt ct ngang ch c thnh phn ng sut tip tc dng. Khi vng trn Mo c tm trng gc ta ) . (1) (13 1E Eu S ha bi Trung tm Hc liu - HTNhttp://www.lrc-tnu.edu.vn/ . Cc phng chnh xin gc 45o so vi ng sut tip. Do o cc strain gauge dn trn trc ch ch bin dng di. Nh vy ta c: u= LL(2) Cn bng 1 v 2, thay = pwM= ) 1 (164 3DM ta c G=LL. 2=) 1 (. 84 3D LM L Kim nghim iu kin bn ca trc: Max [ ] hay pwM[ ]; vi Wp=163D(1-4); 4 3116DM[ ] vy D34116 M [ ] - ng sut tip cho php, c xc nh theo cc cch[ ]=n0, ng sut gii hn ca vt liu, n- h s an ton; [ ]=2, nu da vo thuyt bn ng sut tip ln nht. [ ]=3,nu da vo thuyt bn th nng bin i hnh dng II. Cm bin bin dng (strain gauge) 1. Cu to strain gauge Nm1856,LordKelvinbocorngintrcadyngvthp tnglnkhichuko.Nhnxtnytorasphttrincacmbinbin dng(straingauge)vonm1939tihcvincngnghCalioforniavhc Vin Cng ngh Massachusetts. Ngy nay Strain gauge cch to bng bn dn hay kim loi m in tr ca n thay i khi c tc ng ca ngoi lc. GistacdydnvichiudiL,chulcko(nn),lcko(nn) lm bin dng tng ng theo t l, gi s bin dng lL. Kch thc dy dn bin dng l L+ l hoc L- l. T l LL gi l bin dng. V d: Khi mt dy dn c chiu di 100mm b bin dng, chiu di bin dng l L =0,1mm vy bin dng l: 1001 , 0=0,001=1000.10-6 S ha bi Trung tm Hc liu - HTNhttp://www.lrc-tnu.edu.vn/ Hnh 2.3: M t lc tc dng v bin dng ca dy dn Cc dy dn in c ch to bng phng php khc t mt l kim loi mng, to thnh li kim loi, mc ch nhm tng chiu di dy dn chiu dy li kim loi t 3-6m. Li kim loi c t trn mt tm nha mng t 15-16 m v c p vi 1 film mng. Hnh 2.4: Cu to mt strain gaugse in hnh Khi c lc tc dng trc quay b bin dng, cc strain gauges dn trn trn trcquaybindngtheonhtorasthayiintrcalikimloi. Qu trnh thay i in tr t l vi bin dng ca trc chu xon. Lc tc dng c o gin tip thng qua s thay i thng s in tr R ca li kim loi. S thay i ny t l chnh xc vi lc tc dng. 2) Phn loi strain gaugeHin nay, ngi ta s dng ph bin 2 loi cm bin bin dng: + Cm bin in tr l loi cm bin th ng, c ch to t vt liu c in tr bin thin theo mc bin dng, c kch thc nh t vi mm n vi cmvkhiochngcdntrctiplncutrcbindng.Chngcs dng rng ri trong lnh vc o lng c kh, hng hi, hng khng, kin trc xy dng, y t , s dng nhiu trong ch to loadcell, cm bin o moment, p sut S ha bi Trung tm Hc liu - HTNhttp://www.lrc-tnu.edu.vn/ +Cmbinuodngdyrungcdngchyutrongngnhxy dng. u o c lm bng mt si dy kim loi cng gia 2 im ca cu trc cn o bin dng. Tn s dy rung l hm ca sc cng c hc, tn s ny thay i khi khong cch gia 2 im ni thay i. 3) Thng s c bn v cc c trng ca strain gauge in tr ca cm bin c xc nh bi biu thc: R=Sl Phng trnh vi phn SSLLRR Bin dng dc DL ca dy ko theo bin dng ngang ca tit din, quan h gia bin dng ngang v bin dng dc c dng LLddbbaa; Tit din ngang ca dy S=a.b hoc S=42d ta c LLSS2mt khc, i vi u o kim loi: VVC ;C l hng s Bridman; V: Th tch dy; v V=S.L ta c 2 1 (VV)LLVy ta c: LLKLLCRR. ) 2 1 ( 2 1HsKcgilhsuo(Gaugefactor).Gitrxcnhtheo biu thc:K=1+2 +C(1-2 ); Vi3 , 0 ; C 3 thK2 Ta c Mi lin h gia R v: LLGF RR. * Cc c trng ch yu - in tr sut: in tr ca vt liu lm dy phi ln dykhng qu di lm tng kch thc cm bin v tit din dy khng qu b lm gim dng o dn n lm gim nhy. S ha bi Trung tm Hc liu - HTNhttp://www.lrc-tnu.edu.vn/ -Hsuo(Gaugefactor):thngckhiulGFhocKv c xc nh nh sau: GF=LLRR ThngthngGF=2-3,ngoitrIso-ElasticcGF=3.5vPlatin- vonfram GF=4.1 - nh hng ca lc n tuyn tnh: Trong gii hn n hi, h s u o khngidoquanhtuyntnhgiaintrvbindng.Ngoigii hn n hi, khil/l>0.5%-20% ty theo vt liu, h s u o GF =2. -nhhngcanhit:NichungGFtchunhhngcanhit ,ngoitr isoelastic.Trong khong nhit t-100oC 300oC s thay i ca h s u o GF theo nhit c th biu th qua biu thc: GF (T)= GF [1+K(T-o)] GF : h s u o nhit chun To ( thng To =25oC) K: hsphthucvtliu.ViNichromeVth K =-0.04%/ oC, constantan K=+0.01%/ oC. -nhyngang:ngoi ccnhnh dccin trRLcm bincnc ccon nhnh ngang c tng di lt, in tr Rt,Cc nh sn xut tiu chun ha thng s in tr ca strain gauge vi 3 mc in tr l 120 , 350 v 1000 , S ha bi Trung tm Hc liu - HTNhttp://www.lrc-tnu.edu.vn/ CHNG 3. THIT K, CHTO THIT B O M MEN XON I. Thit k trc chu xon (trc quay) 1. Chc nng: - Truyn m men xon t trc dn ti c cu chp hnh - Lm gi lp cc thit b in t nh: b khuych i, b x l , ngun v b hin th, -Trcphimboiukinbnkhichuxonvimmencgitr Mmax=500Nm.2. Tnh ton thit k trc m bo iu kin bn v cc chc nng ca trc, em chn vt liu gia cng trc l nhm, sau khi rn t b=9000N/cm2

Hnh 3.1: Bn v hnh dng v cc k hiu kch thc trn trc quay - Tnh ng knh trc D0 v d1. + ng sut tip ti thanh trn. Max [ ] hay pwM[ ]; vi Wp=1630D(1-4); 4 30116DM[ ] vy D034116M Theo thuyt bn ng sut tip ln nht[ ]=2, vy [ ] = 4.500N/cm2. S ha bi Trung tm Hc liu - HTNhttp://www.lrc-tnu.edu.vn/ [ ] - ng sut tip cho php ca vt liu chn l 4.500N/cm2. D034555 , 0 1 3,14159 9000000 . 50 16=4,07cm; chn D0=4,32cm, d1=2,4cm; Tnh c =Dd=0,555 - Tnh m men xon ln nht khi D0=4,32cm T biu thc Mmax=max Wp=[ ]1630D(1-4)= 90001632 , 4 14159 , 33(1-4)= 644,49 Nm -Tnh ng knh bu lng d1 v ng knh D2 : Hnh 3.2: Hnh biu din lc tc dng ln mt bch ca trc quay Gi s chiu m men nh hnh v:Theo nguyn l cng tc dng: F1=F2=F3=F4=F Ta c Mmax= 422maxFD; Vy Fmax=422maxDM=4 12 , 052 , 644 2=2.865,39 N Tnh iu kin bn thn bu lng khng b ct; Fmax=41d[ ]; vi [ ]=4500 N/cm2. S ha bi Trung tm Hc liu - HTNhttp://www.lrc-tnu.edu.vn/ d13,14159 * 450039 , 2865 43,14159 * 45004maxF=0,435cm;Vy chn d1= 1 cm. Bng tng hp thng s k thut ca trc xon vi=Dd=0,555 TTThng s K hiu n vGi tr 1Vt liu ch to: Nhm hp kim 2014A 2ng sut tip cho php [ ] [ ]N/cm24500 3M men xon danh nghaMNm500 4M men xon ln nht (qu ti)MmaxNm644,49 5iu kin bn ca trcD0mm40,7 6ng knh ngoi trc lm vicD0mm43,2 7ng knh trong trc lm vicdmm24 8Chiu di ln nhtL2mm206 9ng knh mt bchD3mm173 10ng knh phn b l khoan bu lngD2mm120 11 iu kin bn ca thn bu lngd1mm0,435 12ng knh l bu lng chnd1mm10 13S l bu lngnL4 S ha bi Trung tm Hc liu - HTNhttp://www.lrc-tnu.edu.vn/ 3) Bn v thit k trc quay T bng thng s k thut ca trc quay trn, ta c bn thit k chi tit trc quay nh sau: Hnh 3.3. Bn v thit k chi tit trc quay. Vt liu ch to: nhm mc 2014A, c thnh phn ha hc nh sau: McSiFeCuMnMgCrZnTi 20140,5-0,90,53,9-50,4-1,20,2-0,80,10,250,15 Phi c ch to bng phng php rn. II. Nghin cu la chn strain gauge Ty thuc vo mc phc tp ca h lc cn o m ta la chn s lng, chng loi strain gauge cng nh chn v tr dn strain gauge sao cho ph hp. Tuynhindotitrngtcdnglnphntbindnglmmenxon nntaphisdngcmbinstraingaugeobindngtheophngxin gc 45o vi ng sinh ca trc trn (phn t bin dng). 10 S ha bi Trung tm Hc liu - HTNhttp://www.lrc-tnu.edu.vn/ Hnh3.4:Phngndnstraingaugeln trc quay. Hnh3.5: Bng thng s v hnh dng strain gauge kiu Z23-FA-2-350-11 Thng s chnh ca strain gauge la chn nh sau: -Cngtysnxut:SHOWAMEASURINGINSTRUMENTSCO.,LTD-JAPAN - Kiu: Z23-FA-2-350-11 - Chiu di cng: 2mm; - Mc thay i in tr: 350 0,3%; - Gauge factor: 2,060,2%; - Thermal output: 0,2 ; S ha bi Trung tm Hc liu - HTNhttp://www.lrc-tnu.edu.vn/ III.ng dng mch cu Wheatstone trong vic bin iR ca strain gauge thnh in p Cu Wheatstone l mt mch in c s dng o mt in tr cha bitbngcchcnbnghainhnhcamtmchcu,trongcmtnhnh chaccthnhphnchabit.Hotngcantngtnhmtcuphn th. N c pht minh bi Samuel Hunter Christie vo nm 1833 v c ci tin v ph bin bi Charles Wheatstone vo nm 1843. Mt trong nhng mc ch s dng ban u ca cu Wheatstone l dng vo vic phn tch v so snh (Ekelof, 2001). Hnh 3.6: Mch cu Wheatstone Hnh 3.7: Quarter-Bridge Mt cch tng qut, cu Wheatstone c dng nh Hnh 3.6 cc thnh phn tr khng R1, R2, R3, R4 l cc in tr thun. Cu c kch bng ngun in p VEX, ng ra VO l in th chnh lch gia hai nt a v b. in th VO c tnh V0=(eVR RRR RR).4 143 23 Thng thng khi thit k ngi ta chn cc gi tr in tr sai cho trng thi cn bng R1=R2; R3=R4 hoc R1=R2=R3=R4; Trongccmchcmbin,cuWheatstone c s dng bng cch thay th cc in tr R1, R2, R3, R4trn Hnh 3.6 bng cc strain gauge, ty trng hp m s strain gauge c mc vo cu c th l 1, 2, 3 hoc 4. Do t dng mch cu Wheatstone tng qut ta c cc dng bin th sau: S ha bi Trung tm Hc liu - HTNhttp://www.lrc-tnu.edu.vn/ a) Quarter-Bridge dng mch cu ny, ch c mt strain gauge c s dng, s nguyn l nh Hnh 3.7. Do R1= R3= R4= RG= R, vi RGl in tr ca strain gauge khi cha b bin dng. Khi c tc ng vo vt, in tr ca strain gauge s thay i mt lng R. Khi , VO c tnh: V0=(eVRR).212 nh hng ca nhit Thc t, yu t nhit bn ngoi nh hng trc tip ln in tr ca strain gauge lm gim chnh xc ca kt qu o. Trong trng hp ny hn ch nh hng ca nhit ngi ta s dng thm mt dummy gauge dn vo vt chng nhng trng thi khng hot ng. Hnh3.8:S dngdummy gaugetrnh nhhngca nhit S ha bi Trung tm Hc liu - HTNhttp://www.lrc-tnu.edu.vn/ nh hng ca in tr dy dn Hnh3.9: nhhng caintr dydn mcho dng Quarter-Brige Domchovvtchubindngtxanhaumtkhongcchnht nh nn cn c dy ni gia strain gauge v mch o. Chnh cc on dy dn ny lm xut hin thm thnh phn in tr RL nh trn Hnh 3.9a. Thnh phn in tr ny lm cho cu b mt cn bng ngay c khi khng c tc ng lm strain gauge thay i in tr. Mt khc, in tr ca dy dn cngchutcngcanhitbnngoinnkhinhitthayiRLcng thay i theo lm cho cu b mt n nh hn. hn ch nh hng ca in tr dy dn v nhit ngi ta ci tin bng cch thay i cch u dy dn nh Hnh3.9b. Lc ny c 2 on Aa v aB u c b in tr dy dn v cng chu tc ng ca nhit nn cu s cn bng khi khng c tc ng. on dy dn c in tr RL2mang dng in rt nh v mch o nn in th ri trn dy dn ny rt nh v c th b qua. S ha bi Trung tm Hc liu - HTNhttp://www.lrc-tnu.edu.vn/ b) Half-Bridge Hnh 3.10: Half-Bridge SnguynlvngdngcamchodngHalf-Bridgecgii thiu Hnh 3.10. Mch o Half-Bridge s dng 2 strain gauge trng thi tch ccnhngtrongc1straingaugechunnv1straingaugechuko, nhytng gp i sovi dngHalf-Bridge.Mch thit k dng ny loib nh hng ca nhit . in p lch VO c tnh theo cng thc (3): V0=(EXVRR R).212 c.Full-Bridge Mch Full-Bridge s dng 4 strain gauge, trong c 2 strain gauge chu nn v 2 strain gauge chu ko. S mch Full-Bridge nh Hnh 3.11. Hnh 3.11: Full-Bridge in th Vo c tnh theo cng thc V0=(EXVRR RRR R).2 2 Nh im qua trn, cu Wheatstone hot ng cn phi cp mt in pngunVEX(excitationvoltage).Nguninpnythngcgitrtrong R1R4 R2 R3 V0 i1 i2 i4 i3 VEVe S ha bi Trung tm Hc liu - HTNhttp://www.lrc-tnu.edu.vn/ khong3V15V.Nuinpnylnthindnginchyquaccstrain gaugetrongccnhnhcnglnvthslmnhhngnintrcastrain gauge do nh hng ca nhit bn thn cc strain gauge sinh ra (self- heating). in p kch thch VEXcng nh hng n in p lch Vo ca cu (th hin trong cc cng thc (1), (2), (3)), nu VEX khng c gi n nh th VO

cngskhngnnhvlmnhhngnktquo.Vthmchngun nui cho cm bin c thit k thm chc nng remote sensing. Chc nng ny chophpmchkimtrainpVEXtrnmchcubngnghitipin th dng 2 dy dn sense high v sense low ti im ni dy cp in th kch thch cho cm bin. ng hi tip in th ny a v b ngun so snh v b thm lng in p ri trn dy dn. V th nhng cm bin loi ny tr nn c 6 dy (Hnh 3.12). Hnh 3.12: S nguyn l ca cu 6 dy S ha bi Trung tm Hc liu - HTNhttp://www.lrc-tnu.edu.vn/ IV. La chn b khuych i, b x l, ngun v mn hnh hin th 1. La chn b khuych i. a) Chc nng chnh ca b khuych i - IC c thit k chuyn dng khuych i tn hiu cho cc cm bin, mch o dng cu v na cu. - in th kch thch cho cm bin thay i c v chc nng remote sensing h tr cho cm bin 4 dy v 6 dy -B lc tn hiu (10HZ-20HZ), cho php ty chnh. - H s khuych i thay i c trong khong 2mV/V-5000mV/V Trn th trng c b khuych i 3B18 p ng c yu cu. - in p ngun t cho cm bin c t trc 10V, khi thay i in tr REXT t 300n 1K .in p ra Vo c tnh theo biu thc sau: VO=G.VIN . Trong : VO l in p ra; VIN l in p vo mch G. H s khuych i Hnh 3.13: S khi chc nng ca IC 3B18 S ha bi Trung tm Hc liu - HTNhttp://www.lrc-tnu.edu.vn/ Hnh 3.14 : kt ni u vo 3B18Hnh 3.15. Bng m t chn chc nng Hnh 3.16: M hnh dng sn phm 3B vi cc chn ra b) Tnh h s khuych i G . Vi R3A=GK 200; vi R3A=500vy G=5 , 0200=400 Mun thay i h s khuych i G ch cn thay i gi tr in tr R3A, R3A l bin tr d dng thay i khi s dng. S ha bi Trung tm Hc liu - HTNhttp://www.lrc-tnu.edu.vn/ Cc in tr thit lp khuych i c ci t nh c ch ra nh hnh Hnh 3.17: Ty chnh h s khuych i 2. La chn h thng x l d liu a) Chc nng b vi x l: thu thp x l thng tin t cm bin v truyn tn hiu n mn hnh. Chuyn i d liu t dng tng t sang dng s b) Cu to b vi x l andunio -Bng mch Anduino c 14 cng in/out (nh s 0-13). y l ccchn cm ca Arduino c chc nng input hoc output, to nn ct li ca thit b. - C 6 chn k thut s, c nh du bi du ~ thc hin xung. - Chn 13 c bit c mt LED c ghp vo. Vic ny gip cho vic th nghim. Chng ta th s dng LED c sn, bng cch xut ra chn 13 hoc raccchnkhc.phnbnphidicmtcnganalog6chninput. Chng gip c cc gi tr ca cm bin analog. bn tri l cc cng analog tng t cng ngun, ch cn ngun 3,3 vol hoc 5 vol. - Cui cng, mt cng tc chuyn dng reset Arduino n s gip khi ng li bt k chng trnh no trong b nh. S ha bi Trung tm Hc liu - HTNhttp://www.lrc-tnu.edu.vn/ - Arduino c mt khong b nh, v nu chng trnh qu ln, compiler s bo li. Kt ni: Arduino l mt thit b phn cng c th hot ng c lp (nh mt robot), kt ni vi my tnh, hoc mt thit b Arduino khc, cc thit b in t khc Hnh 3.18. Hnh nh cu to b vi x l andunio 3. Mn hnh hin th a) Chc nng - Hin th kt qu o, b) Cu to Dngc os dng bch th 7 onsngLEDghpli vi nhau theo hnhs 8.Khicho dng dinchyquanhng onthchhpc th hinhnh bt k s no t 0-9 S ha bi Trung tm Hc liu - HTNhttp://www.lrc-tnu.edu.vn/ Hnh 3.19. S mch led 7 on C hai cch mc LED thng dng: LED 7 on sng Ant chung, LED 7 on sng Katt chung.LED7onsngKattchung:Kattcattcccitucni chung vi im c in th bng 0 (hay cc m ca ngun). Tc ng vo du vo (Ant) ca it mc logic 1 it sng. LED7onsngAntchung:Lphngnchnmcnledcho mn hnh hin th ca thit b o. Cc ant c ni chung vi cc dng ca ngun (mc logic 1). Tc dng vo u vo (Katt) ca dit mc logic 0 it sng. S ha bi Trung tm Hc liu - HTNhttp://www.lrc-tnu.edu.vn/ c) S khi mn hnh hin th: Hnh 3.20: S khi mn hnh hin th 4. Ngun cp in p a) Chc nng: Cp in p cho mch cu, b khuych i, b x l v mn hnh hin th. To ngun i xng15V cp ngun nui cho b khuych i; to ngun 5V nui b x l. S ha bi Trung tm Hc liu - HTNhttp://www.lrc-tnu.edu.vn/ b) S mch ngun: Hnh 3.21: S mch ngun S ha bi Trung tm Hc liu - HTNhttp://www.lrc-tnu.edu.vn/ V. Tin hnh dn strain gauge 1. Chun b vt t, dng c a) Vt t cn dng - Trc chu xon: trc mu gia cng theo ng bn v thit k, S lng 01 trc. - Bng dnh loi Scotch. S lng: 02 cun,- Keo dn loi Extra 4000. S lng: 02 tuyp, Hnh 3.22: Keo dn Extra 4000-Showa v bng dnh Scotch -Straingaugekiu:Z23-FA-2-350-11hngsnxut:SHOWA MEASURING INSTRUMENTS CO.,LTD-JAPAN. S lng : 02 chic Strain Gage Pattern Type Nominal Resistance Apporox Gage Fator Dimensionmm RemarksGridBase LengthWidthLengthWidth Z23-MA-2-350-113502.02.0---13.07.0 Uniaxial 45,for shearing strain S ha bi Trung tm Hc liu - HTNhttp://www.lrc-tnu.edu.vn/ - Giy rp mn: 02 t - Dungmi lm sch chuyn dng, cn 700 - Dy dn tn hiu chng nhiu: s lng 50cm. - Cu dn in 4 chn: S lng 01 cu. - B khuych i 3B18, b x l ardunio, ngun cp in, mn hnh hin th. - B hin th: loi Daytronic 3570,b) Thit b phc v th nghim: - My cng c gm: My tin, my mi, my khoan, my phay. - Cc dng c cm tay: My mi, my ct, my nh bng. - M hn, dy hn, ng h o Amprobe AM-570. 2. Cc bc tin hnh dn strain gauge - Bc 1: Lm sch b mt trc quay bng giy rp v dung mi. -Bc2:LyduvtrdntrntrcquayvdnStraingaugelntrc quaytheodu vchsn:Qutrnhlyducthc hin trnmytin m bo chnh xc. Sau lm sch b mt thn trc v cc strain gauge ln 2.Saukhiclmschbmtthntrcvccstraingaugecphbng mt lp keo dnh. Cc strain gauge ny sau c dn ln thntrc - Bc 3:Hn ni to mch cu:Sau khi keo kh, bc lp bng dnh bn ngoi, dng dung mi nh nhang ty ra b mt ca strain gauge. Dng m hn v dy dn hn ni to dy cp ngun vo v dy nhn tn hiu u ra cho mch cu theo s nguyn l 6 dy. - Bc 4: Kt ni u dy tn hiu v in p kch thch ca mch cu vi mch khuych i 3B18 v b x l, ngun nui v mn hnh hin th. - Bc 5. G t cc thit b in t ln trc quay - Bc 6: Ph slicon A900 nn b mt th b in t: B mt dn cc strain gauge v mch in tr ca thit b s c ph mt lp silicon A 900 bo S ha bi Trung tm Hc liu - HTNhttp://www.lrc-tnu.edu.vn/ v straingauge, mch in tr v h thng dy in t khi tc ng ca m mi trng. - Bc 7. Th nghim kho st gi tr in p hin th khi t gi tr m men bit - Bc 8. G t trc quay ln b truyn ng to m men xon. Hnh 3.23. nh trc mu sau khi gn strain gauge. S ha bi Trung tm Hc liu - HTNhttp://www.lrc-tnu.edu.vn/ Hnh 3.24. Hnh nh kim tra nhy xon ca thit b sau khi dn strain gauge bng mn hnh hin tr Daytronic 3570. S ha bi Trung tm Hc liu - HTNhttp://www.lrc-tnu.edu.vn/ Hnh 3.25. Hnh nh thit b o m men xon do hc vin thit k, ch to S ha bi Trung tm Hc liu - HTNhttp://www.lrc-tnu.edu.vn/ Hnh 3.26. Hnh nh kt ni thnh cng strain gauge vi b ngun, b khuych i, vi x l v mn hnh hin th S ha bi Trung tm Hc liu - HTNhttp://www.lrc-tnu.edu.vn/ CHNG 4. XC NHC TNH LM VIC CA THIT B BNG THC NGHIM I. Thit k s th nghim 1. Mc ch:- Xc nh gi in p u ra thng qua m men xon tc dng ln phn t bin dng. a ra mi quan h gia chng. 2. M hnh th nghim 3. Thit b th nghim Thc hin ti Trung tm sng to sn phm, trng i hc KTcng nghip - Thit b to m men xon v c cu hm; - B hin th daytronic 3570 Hnh 4.1. Hnh nh lp t thit b o m men xon trn truc quayln b truyn ng to m men xon o in p u ra Quan h gia m men xon v in p To m men xon cho thit b o S ha bi Trung tm Hc liu - HTNhttp://www.lrc-tnu.edu.vn/ II. Kt qu th nghim 1. Th nghim kho st gi tr in p hin th khi t ti trng bit. Ln lt p ti mmen xon t 0Nm n 500Nm ta c bng gi tr sau: Bng 3 gi tr in p hin th (in p sau khuych i) trn mn hnh (Vo)Th t Gi tr m men xon M (Nm) in p sau khuych i - gi trhin th (Vo)(V) Th t Gi tr m men xon M (Nm) in p sau khuych i - gi trhin th (Vo)(V) 100262500,6352 2100,0278272600,6606 3200,0519282700,6859 4300,0742292800,7114 5400,1016302900,7368 6500,1270313000,7622 7600,1524323100,7663 8700,1778333200,7909 9800,2032343300,8156 10900,2286353400,8638 111000,2541363500,8892 121100,2795373600,9146 131200,2975383700,9400 141300,3222393800,9654 151400,3469403900,9636 161500,3715414000,9883 171600,4065424101,0417 181700,4319434201,0671 191800,4573444301,0925 201900,4702454401,1179 212000,4949464501,1433 222100,5196474601,1687 232200,5442484701,1941 242300,5843494801,2195 252400,6097504901,2103 515001,2350 th biu din quan h in p Vo v m men xon00,20,40,60,811,21,40 100 200 300 400 500 600Gi tr M men (Nm)Gi tr in p (V) th biu din quan h inp Vo v m men xon S ha bi Trung tm Hc liu - HTNhttp://www.lrc-tnu.edu.vn/ Qua th ta thy ng biu din quan h in p v m men l ng tuyn tnh. T ta suy ra c phng trnh biu din quan h M-V nh sau: VO=0,00254M (V) Hoc M=00254 , 0oV (Nm) 2. Thnghim o m men xon trn trc quay. G t thit b o ln trc truyn dn, cho trc xon chuyn ng vi tc 92 vng/pht, ta o c cc gi tr in p v m men nh sau: Bng 4. Bng gi tr hin th in p Vo v gi tr m men tng ng Ln o Gi tr hin th in p hin th V0 Gi tr m men (Nm) in p hin th V0 Gi tr m men (Nm) in p hin th V0 Gi tr m men (Nm) Ln th nghim 1Ln th nghim 2Ln th nghim 3 0000000 10,00291,14100,01757,88780,085031,455 20,087934,6970,087934,3970,219986,550 30,175969,2300,173068,0900,3277128,98 40,2791109,850,252199,2200,4245167,08 50,4110161,770,3140123,590,5170203,49 60,4750186,960,4017158,110,5880231,43 70,5819229,040,4755187,170,7107279,71 80,6800267,650,5521217,290,8107319,10 90,7781306,250,6286247,410,9108358,50 100,8762345,860,7051276,531,0109398,89 110,9743385,470,7816305,651,1110433,28 Kt qu gi tr o mo men xon c biu din di dng th nh sau: th biu din quan h in p v m men0501001502002503003504004505000 0,2 0,4 0,6 0,8 1 1,2in p Vo (V)Gi tr m men (Nm)th nghim ln 1th nghim ln 2th nghim ln 3 Hnh 4.2. th biu din kt qu o m men hin th qua gi tr in p V0 S ha bi Trung tm Hc liu - HTNhttp://www.lrc-tnu.edu.vn/ 3. nh gi kt qu v nhn xt xc nh c gi tr in p u ra khi c m men xon tc dng. Xy dng c phng trnh ch ra mi quan h gia in p v m men - Nghin cu la chn b khuych i 3B18, b x lArdunio gim bt s phc tp trong tnh ton v thit k phn cng. Kt qu th nghim cho thy thit b sau khi ch to p ng c yu cu t ra cho bi ton x l tn hiu strain gaugeng dng trong vic o m men xon. 4. Kt lun v hng nghin cu tip theo - Kt lun: + Tc gi bc u nghin cu, ch to thnh cng thit b o m menxontrntrcquay.Tuynhindoiukinnghincuchtotrong ncnhltiliu,hthngphngthnghimvcnhngvnvti chnhcnkhkhnthiu thnnn chnhxc,tincy ca tn hiu ca thit b vn cha cao. + Thit k, ch tomch o lng strain gauge, b ngun, b khuych i, b x l v kt ni thnh cng mn hnh hin th. - Hng nghin cu tip theo: + Hon thin h thng o m men xon trn trc quay vi s phi hp ca cc chuyn gia v in t nng cao chnh xc ca thit b. +Nghincuvvnngsutmicacmbin,tnhnnh cah thng, nh hng ca nhit n chnh xc ca thit b S ha bi Trung tm Hc liu - HTNhttp://www.lrc-tnu.edu.vn/ 5. Mt s hnh nh ca thit b Hnh 4.3. Hnh nh kim tra nhy xon ca thit b sau khi dn strain gauge bng mn hnh hin tr Daytronic 3570. S ha bi Trung tm Hc liu - HTNhttp://www.lrc-tnu.edu.vn/ Hnh 4.4 Hnh nh thit b o m men xon do hc vin thit k, ch to S ha bi Trung tm Hc liu - HTNhttp://www.lrc-tnu.edu.vn/ Hnh 4.5. Hnh nh kt ni thnh cng strain gauge vi b ngun, b khuych i, vi x l v mn hnh hin th S ha bi Trung tm Hc liu - HTNhttp://www.lrc-tnu.edu.vn/ 6. Chng trnh ci t cho b x l ardunio #include File myFile; /// //int maxin=5; int maxin=3.1; /// float hs1=0.01568; float hs2=0.0156; // const int sw = 2; int state=0; ////// const int data_A =3; const int data_B =4; const int data_C =5; const int data_D =6; //// const int led_A =8; const int led_B =9; const int led_C =10; const int Point =11; /// int sensor = A0;int Value = 0;float out =0; float old =0; int oldvalue=0; float tmp; // int dataout[ ={4,5,6,7,8}; int rest=5; //////////////// void setup() { // set the digital pins as outputs: pinMode(data_A, OUTPUT); pinMode(data_B, OUTPUT); pinMode(data_C, OUTPUT); pinMode(data_D, OUTPUT); pinMode(led_A, OUTPUT); pinMode(led_B, OUTPUT); pinMode(led_C, OUTPUT); pinMode(Point, OUTPUT); pinMode(sw, INPUT); /// if (!SD.begin(4)) { // digitalWrite(5,HIGH); S ha bi Trung tm Hc liu - HTNhttp://www.lrc-tnu.edu.vn/ // return; } tmp=readad(); //tmp=0; } void loop() { out=readad()-tmp; toBCD(out); state=digitalRead(sw); //if (sw==HIGH) toBCD(out); else toBCD(out/400); for (int i=4; i >= 0; i--){ writeled(i,dataout[i]); delay(2); } } float momen(float input){ return (input-hs2)/hs1; } // float mapad(float x, float in_min, float in_max, float out_min, float out_max) { return (x - in_min) * (out_max - out_min) / (in_max - in_min) + out_min; } /// float readad(){ Value = analogRead(sensor); if (abs(Value-oldvalue)>0){ old=mapad(Value,0,1023,0,maxin); oldvalue=Value; return old; } else return old; } void writesd(int value){ myFile = SD.open("example.txt", FILE_WRITE); myFile.println(value); myFile.close(); } void writeled(int pos, int num) { // turn off all of leds digitalWrite(led_A,HIGH); digitalWrite(led_B,HIGH); digitalWrite(led_C,HIGH); // OUT NUMBER FOR PRINTING S ha bi Trung tm Hc liu - HTNhttp://www.lrc-tnu.edu.vn/ switch (num) { case 0: digitalWrite(data_D,LOW); digitalWrite(data_C,LOW); digitalWrite(data_B,LOW); digitalWrite(data_A,LOW); break; case 1: digitalWrite(data_D,LOW); digitalWrite(data_C,LOW); digitalWrite(data_B,LOW); digitalWrite(data_A,HIGH); break; case 2: digitalWrite(data_D,LOW); digitalWrite(data_C,LOW); digitalWrite(data_B,HIGH); digitalWrite(data_A,LOW); break; case 3: digitalWrite(data_D,LOW); digitalWrite(data_C,LOW); digitalWrite(data_B,HIGH); digitalWrite(data_A,HIGH); break; case 4: digitalWrite(data_D,LOW); digitalWrite(data_C,HIGH); digitalWrite(data_B,LOW); digitalWrite(data_A,LOW); break; case 5: digitalWrite(data_D,LOW); digitalWrite(data_C,HIGH); digitalWrite(data_B,LOW); digitalWrite(data_A,HIGH); break; case 7: digitalWrite(data_D,LOW); digitalWrite(data_C,HIGH); digitalWrite(data_B,HIGH); digitalWrite(data_A,HIGH); break; case 8: digitalWrite(data_D,HIGH); digitalWrite(data_C,LOW); digitalWrite(data_B,LOW); digitalWrite(data_A,LOW); S ha bi Trung tm Hc liu - HTNhttp://www.lrc-tnu.edu.vn/ break; case 9: digitalWrite(data_D,HIGH); digitalWrite(data_C,LOW); digitalWrite(data_B,LOW); digitalWrite(data_A,HIGH); } /// TURN ON LED switch (pos) { case 0: digitalWrite(led_A,LOW); digitalWrite(led_B,LOW); digitalWrite(led_C,LOW); digitalWrite(Point,HIGH); break; case 1: digitalWrite(led_A,HIGH); digitalWrite(led_B,LOW); digitalWrite(led_C,LOW); digitalWrite(Point,HIGH); break; case 2: digitalWrite(led_A,LOW); digitalWrite(led_B,HIGH); digitalWrite(led_C,LOW); digitalWrite(Point,LOW); break; case 3: digitalWrite(led_A,HIGH); digitalWrite(led_B,HIGH); digitalWrite(led_C,LOW); digitalWrite(Point,LOW); break; case 4: digitalWrite(led_A,LOW); digitalWrite(led_B,LOW); digitalWrite(led_C,HIGH); digitalWrite(Point,LOW); } } void toBCD(float num){ long newnum=(long)(num*pow(10,4)); for (int i=4;i>=0;i--){ dataout[i]=newnum%10; newnum=newnum/10; }

S ha bi Trung tm Hc liu - HTNhttp://www.lrc-tnu.edu.vn/ TI LIU THAM KHO [1].PGSHVnVui,TSNguynChSng(2006)Staythitkc kh. NXB Khoa hc k thut; [2]. Devdas Shetty Richaro A.Kolk 2001:Mechatronics system design University of Hartford West Hartford, Connecticut [3]. L Quang Minh v Nguyn Vn Vng (2004), Sc bn vt liu tp1, tp 2. NXB Gio dc [4]. Bnh Tin Long, Trn Th Lc, Trn S Tu (2001), Nguyn l gia cng vt liu, Nh xut bn Khoa hc v K thut, H Ni [5]. Trn Vn ch, Nguyn Trng Bnh, Nguyn Th t, Nguyn Vit Tip,TrnXunVit(2003),Cngnghchtomy,NXBKhoahcvk thut, H Ni. [6]. Trn Vn ch (2004), Gia cng tinh b mt chi tit my, NXB Khoa hc v k thut, H Ni. [7]. Dng Minh Tr (2007), Cm bin v ng dng, NXB tr. [8].Ng Din Tp (2004), Vi x l trong o Lng v iu Khin, Nh xut bn, Khoa hc v K thut. [9].Devdas Shetty Richaro A.Kolk, Mechatronics System Design.[10]. Introduction to Mechantronics and Measurement Systems. David G. Alciatore. Michael B. Histand Colorado State University2005 [11]. Lebow products Honeywell Full line catalof 15th editon, 2006 [12] Beaupre GS, Hayes WC, Jofe MH, White AAd, Monitoring fracture site properties with external fixation. [13]B urny FL(1979, 371-382), Strain-gauge measurement of fracture healing. In External fixation The current state of the art (Edited by: al Be). Baltimore: Williams and Wilkins 1979, 371-382 14] V Minh Tr, Mch khuych i Strain gauge dng vi mch chuyn dng 1B31AN, Tp ch khoa hc Trng i hc Cn Th. S 31/2014