LI NI U Ngy nay khoa hc k thut ngy cng pht trin, vi thnh qu l hng lot cc pht minh, cc vt liu mi ra i, mt trong s cc thnh tu ni bt phi ni n l vic pht hin v ng dng sng siu m vo i sng, c bit l trong lnh vc y khoa v thm m vi i din l cc thit b siu m, cc my ty ra, ngoi ra siu m cn th hin s u vit ca mnh trong lnh vc o lng, kim nh cht lng sn phm, an ninh vi cc thit b o khong cch, vn tc, cc thit b cnh bo, d khuyt tt tm hiu thm v mt lnh vc mi v a nng ny em la chn ti My o khong cch ng dng sng siu m lm ti n tt nghip ca mnh. Nhng kin thc v nng lc t c trong sut qu trnh hc tp ti trng s c nh gi trong n tt nghip ny. V vy em s c gng tn dng tt c nhng kin thc hc cng vi kinh nghim tm ti nghin cu qua cc n mn hc c th hon thnh tt n ny.Mc d chng em rt c gng hon thnh tp n ny ng thi hn, nhng khng trnh khi nhng thiu st mong qu thy c thng cm. Em mong c n nhn nhng kin ng gp. Cui cng em xin cm n qu thy c v cc bn sinh vin.Sinh vin thc hin ; Trn Hu ChungNhn xt ca gio vin hng dn----- -----....................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................Nam nh, Ngy......thng.....nm2011Nhn xt ca gio vin phn bin----- -----....................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................Nam nh, Ngy......thng.....nm2011 B Gio Dc V o To Cng Ha X Hi Ch Ngha Vit NamTrng H s phm k thut nam nh c lp-T do- Hnh phc

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H v tn : Trn Hu Chung MSSV : 08GC720011 Lp :CK T 11

Ngnh :K Thut in in TKha : 2008 - 2011 Tn Ti : Nghin cu ,thit k b o khong cch bng sng siu m ng dng vi iu khin1.Cc s liu ban u :.2.Ni dung cc phn thi cng v tnh ton :.3.Cc bn v : - Cc bn v cn thit thuyt trnh .GVHD : Th.s Trn HiuNam nhNgy ..thng..nm .2011Phn I : M u 1.1 t vn Cngvi spht trincakhoahckthut ngycngtinb. Ngnh in t ng gp rt nhiu ng dng rng ri trong i sng, nh du bc nhy vt v khoa hc k thut trong th gii hin i. Nhng tin b ny to nn nhng sn phm mang y tr tu sng to ca con ngi. Trong s pht trin khoa hc , ngnh siu m cng ra i ng gp mt phn quan trng trong s pht trin ny.S kt hp gia lnh vc in t v k thut siu m cho ra nhng sn phmkthut ngdngrt phongphtrongcngnghip, nngnghip, qun s, y hcV vy nghin cu v lnh vc siu m iu quan trng lm nn tng cho cc k thut tin b s dng lnh vc siu m v lm ti liu tham kho cho nhng bn sinh vin sau ny sng to ra nhng ng dng k thut mi v tin b hn.1.2 Gii hn tiC rt nhiu nhng ng dng ca k thut siu m trong nhiu lnh vc ca i sng. Nhng do kin thc v thi gian c hn nn ngi lm ti khng th tm hiu su hn v k thut siu m. Ngi lm ti c th tm hiu nhng vn c bn ca k thut siu m nh sau:+ S lc v sng siu m.+ Cc ng dng c bn ca sng siu m.+ Kho st mch o khong cch bng sng siu m.1.3 Mc ch nghin cu tm hiu su hn v k thut siu m, ta phi tin hnh kho st mch ng dng c th vo thc t. Khi lm thc t s tip xc c nhiu kinh nghim trong qu trnh kho st, m rng kin thc v ng dng siu m v cng c c cc kin thc c bn ca k thut in t.1.4 i tng nghin cuDo thi gian c hn nn ngi nghin cu khng th gii thiu c ht cc ng dng ca siu m.Trong thi gian ngn ch c th tham kho nhng iu c bn ca k thut siu m. V vy, i tng nghin cu ch yu l nhng vn ca k thut siu m m c th l kho st mch o khong cch dng sng siu m.1.5 Gi thit nghin cuVic o khong cch bng sng siu m ny cha c kh thi lm. V vn tc truyn ca sng siu m trong mi cht liu l khc nhau.1.6 Phng php v phng tin nghin cuPhng php tham kho ti liu:Tham kho v chn lc cc ti liu rt ra cc kin thc c lin quan tng hp a vo n. Phng tin: tp ch in t; cc sch k thut chuyn mnPhng php thc nghim:Thchinthi cngtrctipmchintcthrt racckinh nghim thc t v cc quy trnh thc hin c kt qu chnh xc a vo ti. Phng tin: cc dng c lin quan phc v cho qu trnh thi cng.Phn II : Ni dung ti .Chng 1 : Nghin cu h thng o khong cch .1.1 Tng quan v sng siu m 1.1.1Khi nim -Cc mi trng cht n hi (kh, lng hay rn) c th coi nh l nhng mi trng lin tc gm nhng phn t lin kt cht ch vi nhau. Lc bnh thng, mi phn t c mt v tr cn bng bn. Nu tc ng mt lc ln mt phn t A no bn trong mi trng ny, n s ri khi v tr cn bng bn. Do tng tc to nn bi cc mi lin kt vi cc phn t bn cnh, mt mt phn t A b ko v v tr cn bng, mt mt n cng chu tc dng bi lc tc ng nn phn t A s di chuyn qua li quanh v tr cn bng,c ngha l phn t A thc hin chuyn ng di dng dao ng. Hin tng ny tip tc xy ra i vi cc phn t khc ca mi trng. Dng dao ng c, c tnh cht lp i lp li, lan truyn trong mi trng n hi c gi l sng n hi hay sng c, ni mt cch khc, sng l mt hin tng vt l trong nng lng c dn truyn di dng dao ng ca cc phn t vt cht ca mi trng truyn sng. -V bn cht, sng m l sng c hc, do n tun theo mi quy lut i vi sng c, c th to ra sng m bng cch tc ng mt lc c hc vo mi trng truyn m.+ V d 1: Tc ng mt lc lm rung ln m thoa, gy ra cho cc phn t trong khng kh b nn li hay dn ra ty theo hng chuyn ng ca m thoa, phn t u tin b tc ng s nh hng n phn t k tip . . . v c th m c s lan truyn sng ra mi hng (v cng nh th m tai ngi bt k v tr no xung quanh m thoa u nghe c m vang ca m thoa). Hin tng ny tng t nh khi ta th mt vin si vo gia lng h ang lng sng,vin si s to ra nhng gn sng c hnh dng cc vng trn ng tm lan ta ra xung quanh m tm ca chng l v tr m vin si ri xung h nc.+ V d 2: nh vo mt trng; tc ng dng in lm rung mng loa; n bay trong khng kh.Cc i lng c trng ca sng : - Hnh bn di l hnh biu din ca sng, n l mt tp hp ca cc ln nn v dn thay i tun t theo dng hnh sin, trong cc nh sng th hin p lc cao nht cn cc y sng th hin p lc thp nht.Hnh 1.1 : Dao ng ca sng siu mCc i lng c trng ca sng bao gm:o Chu k T = (s) l khong thi gian m sng thc hin mt ln nn v mt ln dn.o Tn s f = (Hz) l s chu k thc hin c trong 1 giy.o Vn tc truyn ca sng m l qung ng m sng m truyn c sau mt n v thi giano di bc sng = (m): l qung ng m sng truyn c sau khong thi gian bng 1 chu k ( = v.T = v/f). Trn hnh v, ta thy bc sng l khong cch gia hai nh hoc hai y nm k nhau.1.1.2Phn loi 1.1.2.1 Phn loi theo phng dao ng Da vo cch truyn sng, ngi ta chia sng c ra lm hai loi: sng dc v sng ngang.o Sng ngang l sng m phng dao ng ca cc phn t ca mi trng vung gc vi tia sng. Sng ngang xut hin trong cc mi trng c tnh n hi v hnh dng. Tnh cht ny ch c vt rn.o Sng dc l sng m phng dao ng ca cc phn t mi trng trng vi tia sng. Sng dc xut hin trong c mi trng chu bin dng v th tch, do n truyn c trong cc vt rn cng nh trong mi trng lng v kh.1.1.2.2 Phn loi theo tn s - Sng m c chia theo di tn s thnh 3 vng chnh.o Sng m tn s cc thp, hay cn gi l sng h m (Infrasound): f < 16 Hz. V d: sng a chn.o Sng m tn s nghe thy c (Audible sound): f= 16 Hz 20 kHzo Sng siu m (Ultrasound): f > 20kHzCc ngun sng siu m c trong t nhin: Di, mt vi loi c bin pht sng siu m nh hng Ni chung cc sng ny nm trong vng tn s20 100 kHz. Sng siu m ng dng trong y hc c tn s t 700 KHz n 50 MHz trong siu m chn on s dng cc tn s t 2 MHz n 50 MHz.1.1.3Lch s pht trin ca sng siu m- c bit n l cha ca siu m, Sergei Y. Sokolov, nh khoa hc ni ting ca Lin X ti VI Ulyanov (Lenin) Vin K thut in, Leningrad sinh nm 1897 ti thnh ph cng tn ca nc Nga. ng a ra tng vo nm 1928, v mt vi nm sau chng minh k thut truyn qua pht hin khuyt tt trong kim loi. ng ci tin tng ca mnh trong cui nhng nm 1920, thi im nhng cng ngh cn thit nh vy khng tn ti. ng xut rng k thut ny c th c s dng pht hin tnh khng ng nht trong cht rn nh kim loi.-Cng vi nhng khm ph ban u v siu m, cc cng trnh nghin cu su rng nhm pht hin khuyt tt trong cc kim loi c tin hnh ti cvounhngnm1930. Nm1933, OMuhlhauser ccpbng sng ch cho h thng truyn nng lng siu m vo chi tit kim tra, pht hin khuyt tt khng ng nht bng s dng b bin i siu m-in th cp. Nm 1935 Sokolov cng b chi tit cc thit k th nghim my pht thch anh, phng php cp ghp ni my pht in vi cc b phn kim tra nhm t c nng lng truyn n ti a, v nhiu phng php pht hin nng lng siu m sau khi truyn qua cc tit kim tra. ng xut khi nim my chp nh siu m u tin cha hnh nh thc thu nhn ca mt khuyt tt. ng cho bit rng bng cch s dng sng m vi tn s 3000 MHz, phn gii thu c c th bng phn gii ca cc knh hin vi quang hc. Phng php ca ng s dng mt b chuyn i nhn tn hiu p in ln khi in tch to ra bi cc tn hiu m thanh n trng thi c lp. B mt ca b chuyn i sau c qut bi tip xc c hc hoc khong cch, xy dng hnh nh ca khuyt tt ny. phn gii ca cc thit b th nghim m ng ch to c tuy nhin khng tt c s dng mc thc t.Ti c, nm 1936, Raimar Pohlman pht trin mt phng php to nh siu m da trn s truyn qua s dng ng truyn sng m v chuyn i hnh nh kt qu sng thanh thnh hnh nh quan st c trong cng mt th tch d. Ti c, thit b chuyn i hnh nh ca ng c bit n nh l t bo Pohlman. c s dng rng ri vo gn cui giai on chin tranh th gii II ti c khi th nghim vt liu siu m tr nn cn thit trongviclachnndcbovphophngkhngcaBerlin. Pohlman thc hin thc nghim theo cc tuyn tng t vi s truyn siu m qua kim loi c khuyttt,nhng s dng mt cch tip cn hon ton khc vi phng php pht hin chm tia nhn c. My d ca ngnhch sdngmt mingnhmdngbngtuyt trongxylenkn ng trong mt v trong sut. Chm siu m nhn c t mu th nghim tcnglnmingnhmhnhbngtuyt khinchngtspxpbnh thng theo hng chm siu m.Trong trng hp c khuyt tt xut hin trong vt liu khi th nghim,cc vng ti s c thay th ti v tr cc bng tuyt duy tr nh hng ban u ca chng.Nhng ngi c ng gp quan trng, Floyd Firestone,Donald Sproule v Adolf Trost khng h bit n nhaunh th h lm vic trong b mt vy. Kcccngdngbngsngchcahccngb. Sproule v Trost s dng cng ngh truyn qua vi cc u d truyn v nhnsiumhontonringbit. Trost pht minhraci gi l Trost-Tonge. Hai u d c ni theo hng i din vi tm,t trn cng mt trc bng mt thit b c kh - the tonge - v to cp kt hp vi c hai mt bng dng nc chy lin tc. Sproule t 2 u d trn cng mt pha ca vt. V vy, ng pht minh ra my d tinh th kp. ng s dng s kt hpnycngvi cckhongcchkhcnhautchng. Firestone l ngi u tin nhn ra k thut phn x. ng sa i mt thit b radar v pht trin mt my pht c cc xung ngn v b khuch i vi vng ngng ngn (dead zone). Sproule cui cng t b phng php truyn qua v np mt bng sng ch vo nm 1952 mang tn nhng ci tin trong/hoc lin quan n thit b pht hin khuyt tt v o vn tc bng phng php siu m vng.1.2 H thng o khong cch1.2.1 Cc phng php o khong cch truyn thng1.2.1.:Phng php o bng thc - Trong trng hp khng cn chnh xc cao ngi ta c th o bng cch m bc. Mi bc chn ca ngi bnh thng cch nhau 0,7m. Cch o ny c chnh xc rt thp. Do trong mi trng hp u cn c thc g hay thc thp (dy) o.-Thc thp (dy) thng thng di 25m dng km vi mt b 11 que st. Khi o cn c hai ngi thao tc. Ngi i sau cm u thc c vch 0m, dng que st gi cht u thc sao cho vch 0m ca thc trng vi im u cn o. Ngi i trc cm 10 que st v cm que st ti vch 25m u chnh sao cho hng ca thc trng vi hng o. Hai ngi i ti v o tip tc, ngi i sau thu cc que st m ngi i trc cm. Khi thu 10 que ngi i sau s giao cho ngi i trc.Nu gi: - N: S ln ngi i sau trao b 10 que st cho ngi i trc. - n : S que st trong tay ngi i sau -r : Khong l cn li c trn thc. - 25 : l chiu di ca thc. nu thc di 30m th s ny c thay bng 30. -S: Khong cch c o. Ta c cng thc tnh khong cch bng:Hnh 1.2:o khong cch bng thc o- Khio nu gp a hnh dc t th c th nng thc ln nm ngang v dng ng thng bng kim tra thng bng. khi u thc nng cao c treo mt dy di nh tm u thc mt t. - Nu a hnh dc u ta c th o trc tip mt t nghing v dng cng thc: Trong : l di o nghing;d khong cch AB; agc nghing ca mt t.Hnh 1.3 :o bng lng gic 1.2.1.2 Phng php xc nh khong cch bng lng gic -Phng php ny s dng mt ngun pht sng pht ra mt chm tia hp ti p vo b mt vt th. Do phn x, tia sng chuyn hng ti b thu c t cch b pht mt khong B, gc pht tia sng so vi phng ngang l ( hnh 1.4).Hnh 1.4: Sensor o khong cch s dng phng php lng gic. Nu D l khong cch ti tng ti detector th khong cch ny c tnh nh sau: D = B. tg1.2.1.3 Phng php xc nh khong cch bng o khong thi gian truyn sng -Trong phng php ny s dng ngun pht lazer xung pht ra xung sng, sau thu li nh sng phn x ca n vi iu kin chm sng i v chm sng v phi ng trc. Khi khong cch t sensor ti i tng s c tnh nh sau: D = C . T/2 Trong : D l khong cch t sensor ti i tng . C l vn tc truyn nh sng T l thi gian k t khi pht xung sng cho ti khi nhn c xung sng. -Vi cng thc ny, o khong cch D s gp phi kh khn l khong thi gian T thng rt nh c picrogiy. Thc t, ngi ta thng s dng o thi gian tr gia sng pht ra v sng phn x. Trong cch ny, mt ngun laser s pht lin tc, b o s thc hin o pha gia hai sng ti v sng phn x. S thc hin c th c ch ra trn hnh 1.2.1.3- Trong s , chm laser pht c ti mt gng bn m, gng ny s chia chm laser thnh hai chm sng nh nhau. Mt truyn ti i tng, mt truyn ti b o pha. Chm laser truyn ti i tng s phn x v i ti b o pha. B o pha y ng vai tr l mt detector. Gi L l khong cch t tia chun ti Detector, D l khong cch t i tng ti gng bn m.Khi tng qung ng i ca laser ti vt th v quay tr v Detector l : D = 2D + L Hnh 1.5: o khong cch bng pha- Nu i tng gn (D = 0) khi pha ca hai tia sng nh nhau. Khi D tng th lch pha tng dn dch pha gia hai tia trong trng hp ny s l: D= L + ./3600 do D = ./ (2. 3600 ). - Cng cn lu : khi = 3600 b o pha s khng phn bit c D = L + n(vi n l s nguyn ) hay D = L. Nh vy cch ny ch o vi cc gi tr lch pha < 3600 hay vi khong cch 2D < . Bn cnh vic s dng o khong cch bng ngun pht lazer, trn thc t ngi ta cn s dng ngun thu pht siu m. Chm xung siu m pht ra p ti b mt phn x ca i tng, xung phn x c thu u thu siu m c thi gian ko di xung t l vi khong cch t sensor ti vt. Nu o c khong thi gian ko di xung phn x ta hon ton c th o c khong cch ti vt. 1.2.2 Phng php o khong cch ng dng + ) o khong cch bng cm bin siu m :- Loi sensor ny pht ra xung siu m. Nu tn ti vt th trong vng lm vic ca sensor s xut hin sng phn x v u thu. Cu trc mt sensor siu m thng gm nhng phn : Phn t c bn ca sensor ny l b bin m thng l gm p in c bo v bng mt cht nha tng hp nhm chng li s m t, bi bn v cc nhn t khc ca mi rng. B thu m thanh s hng m a ti b bin i m thanh thnh tn hiu in. Tt c cc thnh phn ny c trong mt v.-- Mt dng sng in hnh m t hot ng ca sensor siu m. Dng sng A l tn hiu iu khin tn hiu truyn. Dng sng B l tn hiu li ra khi c c tn hiu ting vng (echo) trong B1 l tn hiu pht ra cn B2 l tn hiu phn x li. Cc xung C tch bit tn hiu truyn v tn hiu nhn. phn bit s khc nhau gia cc xung tng ng vi tn hiu mang v tn hiu phn x li ta xem xt tn hiuD. Trong t1 l khong thi gian pht hin nh nht v t1+ t2 l khong thi gian pht hin ln nht. Cc khong thi gian ny tngng vi khong thi gian truyn sng trong mi trng khi nhn c tn hiu phn x li (lc tn hiu D c gi tr ln nht) s hnh hnh tn hiu E, n s bng 0 khi kt thc xung tn hiu A. Cui cng tn hiu F c hnh thnh khi xut hin xung tn hiu E v s l tn hiu ra ca sensor siu m hot ng theo ch nh phn .1.2.3ng dng ca sng siu m ROBOT M SN PHM

TY RA PHT HIN T NHPHnh 1.6: Mt s ng dng sng siu m1.3 S khi1.3.1 S khi o khong cch Hnh 1.7 : S khi my o khong cch1.3.2Chc nng tng khi Khi ngunbaogmngunn+5Vngunnui cavi iukhin, 12V cp ngun nui cho mch to xung pht, cp cho mch x l tn hiu thu. Khi hin thly d liu t khi x l trung tm v hin th chng trn mn hnh LED. Khi to xung pht to ra xung pht 40Khz a n bin t pht ra mi trng o. Khi x l tn hiu thu c nhim v nhn tn hiu phn hi, khuch i v iu ch thnh xung kch gi v khi iu khin trung tm. Khi iu khin trung tm c nhim v: Giao tip bn phm iu khin. Nhn tn hiu iu ch t khi nhn v x l tn hiu thu kch dng b m 8 bitChng II : H thng o khong cch 2.1Khi cm bin :2.1.1Cm bin siu m :2.1.1.1: Mt s loi cm bin siu m :Khi x l trung tmKhi xung phtthu v x l Khi tn hiu thuKhi ADCKhi hin thKhi ngunBnphmphmphmHnh 2.1. : Mt s loi cm bin siu mCm bin sin m c nhiu loi, ty theo cng dng nh nhn bit vt trong khong cch gn hay xa, nhn bit cc vt c tnh cht khc nhau v trong nhng iu kin hot ng khc nhau m ngi ta ch to cc loi cm bin siu m cng khc nhau.2.1.1.2 : Cm bin siu m v nguyn tc TOF (Time Of Flight)Sng siu m c truyn i trong khng kh vi vn tc khong 343m/s. Nu mt cm bin pht ra sng siu m v thu v cc sng phn x ng thi, o c khong thi gian t lc pht i ti lc thu v, th my tnh c th xc nh c qung ng m sng di chuyn trong khng gian. Qung ng di chuyn ca sng s bng 2 ln khong cch t cm bin ti chng ngoi vt, theo hng pht ca sng siu m.Hay khong cch t cm bin ti chng ngi vt s c tnh theo nguyn l TOF:d = v t/2Hnh 2.2 : Nguyn tc TOF ca cm bin siu m2.1.1.3 : Tm qut ca cm bin siu m :Cm bin siu m c th c m hnh ha thnh mt hnh qut, trong cc im gia dng nh khng c chng ngi vt, cn cc im trn bin th dng nh c chng ngi vt nm u . Hnh 2.3 : Tm qut ca cm bin siu m2.1.1.4 Thng s mt s loi cm bin siu m SRF Cm bin Thng tin Range Angle * Echoes ** Thi gian khc nhau, Ghi chTi thiu Ti a SRF02 I2C / Serial 15 cm6 m45 M t70 msA SRF04 K thut s 3 cm3 m45 M t 100 s - 36 ms SRF05 K thut s 3 cm4 m45 M t 100 s - 36 ms SRF08I2C3 cm6 m45 1765 msBC SRF10I2C3 cm6 m60 M t65 msAB SRF235I2C10 cm1,2 m15 M t10 msADBng 2.1 : Thng s cc loi cm bin*: c tnh gc ca hnh nn cm bin 1 / 2 cm bin**: S vang ghi li bi cm bin.y l nhng ting vng ghi t c gn y nht, v c ghi mi bng mi ln khc nhau. A: Nhng cm bin nh hn in hnh (SRF 05/04 / 08) kch thc. B: Phm vi thi gian c th c iu chnh xung bng cch iu chnh c. C: cm bin ny cng bao gm mt photocell mt trc pht hin nh sng. D: Hot ng mt tn s 235kHz cao hn. 2.1.2 : Cm bin siu m SRF05 v c im k thut2.1.2.1 : Gii thiu + SRF05 l mt bc pht trin t SRF04, c thit k lm tng tnh linh hot, tng phm vi, ngoi ra cn gim bt chi ph. SRF05 l hon ton tng thch vi SRF04.Khong cch c tng t 3 mt n 4 mt. + SRF05 cho php s dng mt chn duy nht cho c kch hot v phn hi, do tit kim gi tr trn chn iu khin.Khi chn ch khng kt ni, th SRF05 hot ng ring bit chn kch hot v v chn hi tip, nh SRF04. SRF05 bao gm mt thi gian tr trc khi xung phn hi mang li iu khin chm hn chng hn nh b iu khin thi gian c bn Stamps v Picaxe thc hin cc xung lnh.2.1.2.2 :Cc ch ca SRF05 Ch 1 : Tng ng SRF04 tch bit kch hot v phn hi -Ch ny s dng ring bit chn kch hot v chn phn hi, v l ch n gin nht s dng. Tt c cc chng trnh in hnh cho SRF04 s lm vic cho SRF05 ch ny. s dng ch ny, ch cn chn ch khng kt ni - SRF05 c mt ni dng trn chn ny . Hnh 2.4 : S chn ca SRF05Hnh 2.5 : Gin nh thi ca SRF05 ch 1 Ch 2 Dng mt chn cho c kch hot v phn hi -Ch ny s dng mt chn duy nht cho c tn hiu kch hot v hi tip, v c thit k lu cc gi tr trn chn ln b iu khin nhng. s dng ch ny, chn ch kt ni vo chn mass.Tn hiu hi tip s xut hin trn cng mt chn vi tn hiu kch hot.SRF05 s khng tng dng phn hi cho n 700uS sau khi kt thc cc tn hiu kch hot. s dng ch 2 vi cc Stamps BS2 c bn, ta ch cn s dng PULSOUT v PULSIN trn cng mt chn, nh sau :SRF05PIN 15:s dng pin cho c hai v kch hot echoRangeVAR Word: xc nh phm vi bin 16 bitSRF05 = 0: bt u bng pin thp PULSOUT SRF05, 5:a ra kch hot pulse 10uS (5 x 2uS) PULSIN SRF05, 1,Range :echo o thi gian Range = Range/29 : chuyn i sang cm(chia 74 cho inchHnh 2.6 : Gin ch 2 ca SRF05 Tnh ton khong cch :Gin nh thi SRF05 th hin hai ch trn; Ch cn cung cp mt on xung ngn 10uS kch hot u vo bt u o khong cch. Cc SRF05 s cho ra mt chu k 8 burst ca siu m 40khz v tng cao dng phn hi ca n (hoc kch hot ch dng 2). Sau ch phn hi, v ngay sau khi pht hin n gim cc dng phn hi li.Dng phn hi l mt xung c chiu rng t l vi khong cch n i tng.Bng cch o xung, ta hon ton c th tnh ton khong cch theo inch / centimt hoc n v o khc.Nu khng pht hin g th SRF05 gim thp hn dng phn hi ca n sau khong 30mS. SRF05 c th c kch hot nhanh chng vi mi 50mS, hoc 20 ln mi giy. Nn ch 50ms trc khi kch hot k tip, ngay c khi SRF05 pht hin mt i tng gn v xung phn hi ngn hn. iu ny l m bo cc siu m "beep" phai m v s khng gy ra sai phn hi ln o k tip. Cc thit lp khc ca chn 5 Chn 5 c ng nhn l "programming pins" c s dng mt ln duy nht trong qu trnh sn xut lp trnh cho b nh Flash trn chip PIC16F630. Cc chng trnh ca PIC16F630 pins cng c s dng cho cc chc nng khc trn SRF05, nn chc chn rng khng kt ni bt c ci g vi cc chn ny, nu khng s lm gin on hot ng m-un. Thay i chm tia v rng chm Chm tia ca SRF05 c dng hnh nn vi rng ca chm l mt hm ca din tch mt ca cc cm bin v l c nh. Chm tia ca cm bin c s dng trn SRF05 c biu din bn di:2.1.2.3.Hot ng pht v nhn phn hi sng m c bn ca SRF05 : Nguyn tc c bn ca sonar: l to ra mt xung m thanh in t v sau lng nghe ting vng to ra khi cc ln sng m thanh s truy cp mt i tng v c phn x tr li. tnh thi gian cho phn hi tr v, mt c tnh chnh xc c th c lm bng khong cch ti i tng.Xung m thanh to ra bi SRF05 l siu m, ngha l n l trn phm vi nhn xt ca con ngi.Trong khi tn s thp hn c th c s dng trong cc loi ng dng, tn s cao hn thc hin tt hn cho phm vi ngn, nhu cu chnh xc cao.Hnh 2.7 : Nguyn tc hot ng ca SRF05+ Mt s c im khc ca cm bin siu m SRF05 Mc ca sng m hi tip ph thuc vo cu to ca i tng v gc phn x ca n+ Vng pht hin ca SRF05 - Nu ngng pht hin i tng c t qu gn vi cm bin, cc i tng trn mt ng c th b va chm ti mt im m. Nu ngng ny c t mt khong cch qu ln t cc cm bin th cc i tng s c pht hin m khng phi l trn mt ng va chm. - Mt k thut ph bin lm gim cc im m v t c pht hin chiu rng ln hn c ly gn l thm mt ci tin bng cch thm mt n v SRF05 b sung v gn kt ca hai n v hng v pha trc. Thit lp nh vy th c mt khu vc m hai khu vc pht hin chng cho ln nhau.2.2 : Khi Vi iu khin 2.2.1 Gii thiu VKB vi iu khin vit tt l Micro-Controller, l mch tch hp trn chp c th lp trnh c, dng iu khin hot ng ca h thng. Theo cc bc iu khin ca ngi lp trnh, vi iu khin c th c, lu tr thng tin, x l thng tin, o thi gian v tin hnh ng m mt c cu no .Trong cc thit b in v in t dn dng, cc b vi iu khin, iu khin hot ng ca TiVi, my git, u c laser, in thoi, l vi baTrong h thng t ng, b vi iu khin c s dng trong Robot, dy chuyn t ng. Cc h thng cng thng minh th vai tr ca h vi iu khin cng quan trng.2.2.1.1 LCH S PHT TRIN CA VI IU KHINB vi iu khin thc ra, l mt loi vi x l trong tp hp cc b vi x l ni chung. B vi iu khin c pht trin t b vi x l, t nhng nm 70 do s pht trin v hon thin v cng ngh vi in t da trn k thut MOS (Metal-Oxide-semiconductor),mc tch hp ca cc linh kin bn dn trong mt chp ngy cngcao.Nm1971xut hinbvi xl 4bit loi TMS1000docngtyTexas Intruments va l ni pht minh va l ni sn xut. Nhn tng th th b vi x l ch c cha trn mt chip nhng chc nng cn thit x l chng trnh theo mt trnh t, cn tt c cc b phn ph tr khc cn thit nh: b nh d liu, b nh chng trnh, b chuyn i A/D, khi iu khin, khi hin th, iu khin my in, khi ng h v lch l nhng linh kin nm bn ngoi c ni vo b vi x l.Min nm 1976 cng ty Intel(Interlligen-electronics) cho ra i b vi iu khin n chip u tin trn th gii vi tn gi 8048. Bn cnh b vi x l 8048 trung tm cn cha b nh d liu, b nh chng trnh, b m v pht thi gian cc cng vo v ra Digital trn mt chp.Cc cng ty khc cng ln lt cho ra i cc b vi iu khin 8 bit tng t nh8048vhnhthnhnnhvi iukhinMCS-48(Microcontroller system-48).n nm 1980 cng ty Intel cho ra i th h vi iu khin th hai n chp vi tn gi 8051. V sau hng lot cc vi iu khin cng loi vi 8051 ra i v hnh thnh nn h vi iu khin MCS-51.n nay h vi iu khin 8 bit MCS 51 c n 250 thnh vin v hu ht cc cng ty hng u trn th gii ch to. ng u l cng ty Intel v rt nhiu cng ty khc nh: AMD, SIEMENS, PHILIPS, DALLAS, OKINgoi ra cc cng ty khc cng c cc h vi iu khin ring nh:H68HCOS Ca cng ty MotorolaHST62 Ca cng ty SGS-ThomsomHH8 Ca cng ty HitachiH Pic Ca cng ty Microchip2.2.2 KHO ST H VI IU KHIN AT89XXIC vi iu khin AT89XX thuc h MCS-51. C cc c im sau: 8 Kbyte Eprom bn trong. 128 byte Ram ni. Port xut/nhp I/O 8 bit. Giao tip ni tip. 64 Kbyte vng nh m ngoi. 64 Kbyte vng nh d liu ngoi. X l Boolean (x l lun l hot ng trn bit n). 210 v tr nh c th nh v bit. 4s cho hot ng nhn hoc chia.2.2.2.1 CU TRC BN TRONG CAAT89XXHnh 2.2.2.1 : S khi ca ca vi iu 89XXPhn chnh ca vi iu khin AT89XX l b x l trung tm CPU (central Processing Unit) bao gm: Thanh ghi tch ly A Thanh ghi tch ly ph B, dng cho php nhn v php chia n v logic hc (ALU: Arithmetic Logical Unit) T trng thi chng trnh (PSW: Program Status Word). Bn Bank thanh ghi. Con tr ngn xp.Ngoi ra cn c b nh chng trnh, b gii m lnh, b iu khin thi gian v logic.n v x l trung tm nhn trc tip xung t b dao ng, ngoi ra cn c kh nng a mt tn hiu gi nhp t bn ngoi.Chng trnh angchy c thcho dngli nhmtkhiiukhin ngt bn trong. Cc ngun ngt c th l : cc bin c bn ngoi, s trn b m nh thi hoc cng c th l giao din ni tip.Cc cng (port 0, port 1, port 2, port 3) c s dng vo mc ch iu khin. Port 3 cn c thm cc ng dn iu khin dng trao i vi mt b nh bn ngoi, hoc giao tip ni tip v cc ng ngt dn bn ngoi.Giao tip ni tip c cha mt b truyn v b nhn khng dng b lm vic c lp vi nhau. Tc truyn qua cng ni tip c th t trong di rng v c n nh bng mt b nh thi.Trong b vi iu khin AT89XX c hai thnh phn quan trng khc l b nh v cc thanh ghi.B nh gm c b nh Ram v b nh Rom dng lu tr d liu v m lnh.Cc thanh ghi s dng lu tr thng tin trong qu trnh x l. Khi CPU lm vic n lm thay i ni dung ca cc thanh ghi.2.2.2.2 CHC NNG CC CHN VI IU KHINHnh 2.2.2.2: S chn vi iu khin Port 0: l Port c hai chc nng t chn 32 n chn 39.Trong cc h thng iu khin n gin s dng b nh bn trong khng dng b nh m rng bn ngoi th Port 0 c dng lm cc ng iu khin IO (Input-Output).Trong cc h thng iu khin ln s dng b nh m rng bn ngoi th Port 0 c chc nng l Bus d liu AD7-AD0. Port 1: Port 1 c s th t chn t 1-8. Port 1 ch c mt chc nng dng lm cc ng iu khin xut nhp IO, Port 1 khng c chc nng khc. Port 2: l port c hai chc nng vi s th t chn t 21-28.Trong cc h thng iu khin n gin s dng b nh bn trong khng dng b nh m rng bn ngoi th Port 2 c dng lm cc ng iu khin IO (Input-Output).Trong cc h thng iu khin ln s dng b nh m rng bn ngoi th Port 2c chc nng l Bus d liu AD8-AD15. Port 3: l port c hai chc nng vi s th t chn t 10-17. Cc chn ca port ny c nhiu chc nng, cc cng dng chuyn i c lin h vi cc t tnh c bit ca 89XX nh bng sau:Bit Tn Chc nng chuyn iP3.0P3.1P3.2P3.3P3.4P3.5P3.6P3.7RxDTxDINT0\INT1\T0T1WR\RD\Ng vo nhn d liu ni tip.Ng xut d liu ni tip.Ng vo ngt cng th 0.Ng vo ngt cng th 1.Ng vo ca Timer/Counter th 0Ng vo ca Timer/Counter th 1.Tnhiuiukhinghi dliulnbnh ngoi.Tnhiuiukhincdliutbnh ngoi.Bng 2.2.2.2 : chc nng cc chn port 3 PSEN (Program Store Enable): PSENltnhiungrachn29ctcdngchophpcbnh chng trnh m rng v thng ni n chn OE (Output Enable hoc RD) ca Eprom cho php c cc byte m lnh.Khic giao tip vi b nh chng trnh bn ngoi th mi dng n PSEN, nu khng giao tip th chn PSEN b trng.PSEN mc thp trong thi gian vi iu khin ly lnh. Cc m lnh ca chng trnh c t Eprom qua bus d liu v c cht vo thanh ghi lnh bn trong vi iu khin gii m lnh. ALE (Address Latch Enable): Tn hiu ra ALE chn 30 dng lm tn hiu iu khin gii a hp cc ng a ch v d liu khi kt ni chng vi IC cht.Tn hiu ra chn ALE l mt xung trong khong thi gian port 0 ng vai tr l a ch thp nn vic cht a ch c thc hin mt cch hon ton t ng.Cc xung tn hiu ALE c tc bng 1/6 ln tn s dao ng ca t thch anh gn vo vi iu khin v c th dng tn hiu xung ng ra ALE lm xung clock cung cp cho cc phn khc ca h thng.Trong ch lp trnh cho b nh ni ca vi iu khin th chn ALE c dng lm ng vo nhn xung lp trnh t bn ngoi lp trnh cho b nh flash rom trong vi iu khin. EA (External Access):Tn hiu vo EA chn 31 thng c ni ln mc 1 (+5VDC) hoc mc 0 (GND).Nu ni EA ln mc logic 1 th vi iu khin s thi hnh chng trnh t b nh ni.Nu ni EA vi mc logic 0 th vi iu khin s thi hnh chng trnh t n nh ngoi. RST (Reset):NgvoRST chn 9 lng vo Reset ca89XX.Khi tn hiuny c a ln mc cao ( trong t nht l 2 chu k my), cc thanh ghi bn trong vi iu khin s c ti nhng gi tr thch hp khi ng li h thng. Cc ng vo b dao ng trn chip:Vi iu khin AT89XX c mt b dao ng trn chip. N c ni vi thch anh gia hai chn 18 v 19. Tn s thng s dng l 12 MHz. Cc chn ngun:89XXvnhnhvi ngunn+5VDC. VCCcni vochn40v Vss(GND) c ni vi chn 20.Chng III : Thit k v thi cng3.1Nhim v thit k :Nhim v cn thc hin l thit k mt mch o khong cch t 0-300 cm dng sng siu m v iu chnh chnh xc ca mch o theo nhit .o Thit k mch to xung pht sng.o Thit k khi x l tn hiu thu.o Thit k b m.o Thit k khi khng ch b m v hin th vn tc truyn theo nhit .o Thit k khi ngun.3.2Thit k mch to xung pht : Bin t pht (sensor transmitter) Hnh 3.1 : cp bin t siu mK hiu 400STTnh nng Bin t phtTn s hot ng 40kHz p sut m 120dB typ. (0dB=0.02mPa)Gc m lm vic 80 (typ.)in dung 2550pF Nhit chu ng ti thiu-30C Nhit chu ng ti a 80C Khong cch d gn nht 3 cm Khong cch d xa nht 6 m phn gii 9mm in p chu ng20Vp-p Bng 3.1 : Bng thng s bin t thu Dao ng to xung vung 40Khz: C nhiu dng mch dao ng to xung vung khc nhau3.2.1Dao ng dng KTT (Op-amp)-+O P - A M P321R 1C 1R 3R 2Hnh 3.2 Mch to sng vung dng b khuch i thut ton (Op-amp). Nguyn l :Haitrngthicamchtngngvi haimcbohadngvmca khuch i thut ton. Chu k dao ng ca mch c xc nh theo biu thc:31 1222 ln 1RT RCR _ + ,(Theo trang 263 sgk K Thut in T - Lu Ph Lu Phi Yn Nguyn Nh Anh)3.2.2Dao ng dng cng logicDng 1:V o u t7 4 1 41 2RCHnh 3.3 : Mch dao ng to xung vung dng vi mch 7414 (dng 1)IC Tn s741474LS1474HC140.8/RC (R 500)0.8/RC (R 2K)1.2/RC (R 10M) Bng 3.2 :Bng dao ng ca 1 s loi IC V tnp vx qua cng in tr Rnndng sng vungra ixng. Do ngng logic khc nhau nn tn s dao ng ca cng TTL v CMOS khc nhau. Tn s dao ng cn b nh hng bi in tr ng ra ca cng logic v cc yu t v nhit , vvnn cng thc trn ch l xp x. Ngoi ra tn s dao ng cn b gii hn bi gi tr in tr qui nh nn tn s dao ng ca mch ch nm trong khong vi Hz, do mch ny khng c s dng to dao ng tn s cao.Dng 2:R s7 4 1 4 RCV o u t7 4 1 4Hnh 3.4 : Mch to xung vung dng vi mch 7414 (dng 2)A BHnh 3.5 : Dng sng ng raTn s dao ng:Khi dng cng thc trn, in tr R phi ln hn 50K, t C phi ln hn1000 pF. V nguyn l mch dao ng vi khong rng ca in tr R (t vi trm ohm n vi megohm) v t C (t 100pF n hng F), in tr RS khng c qu ln v c th khin mch dao ng chp chn.3.2.3Mch nh thi 555Mch nh thi dng ch cc mch nh thi cc thi gian tr hon (hay rng xung ra) lu. Thng dng nht trong cc mch nh thi l IC 555. Bn cch IC 556 l hai 555 trong mt IC, 7555 l phin bn CMOS ca 555, 7556 l phin bn CMOS ca 556, LM 322 chnh xc hn 555, RX2240 l mch nh thi lp trnh c cn c gi l mch nh gi / mch m.555 hot ng c ch phi n (Mch dao ng) v n n (mch to xung hay to s tr hon). Trong cc ng dng i hi chc nng dao ng a hi ngi ta thng dng 555, i vi cc yu cu c tnh chnh xc cao ngi ta thng dng dao ng thch anh, hoc mch nh thi chnh xc hn LM 322.Cu to ca mch 555VoutVccGNDVccGNDVccGNDVBVAHnh 3.6 : Cu to 555 555 dng lm mch dao ngMch dng hai in tr v mt t xc nh tn s v chu trnh lm vic ca tn hiu ra. Khi va ng in t C in th 0V tc di ngng Vcc/3. Mc thp ny hin hu ng ny lm 555 ny v ng ra ln cao (xp x Vcc 1.7V), ng thi t np v hng Vcc qua hai in tr Ra v Rb, nhng khi t np n gi tr bng ngng trn 2Vcc/3 flip flop lt trng thi v ng ra xung thp (xp x 0V). Lc by gi transistor Tr dn v t x in v hng 0V. Khi in th ca t bng ngng di Vcc/3 flip flop tr li trng thi ban u v ng ra ln cao, transistor Tr ngng dn v t C np li v pha Vcc. Kt qu l ng ra c tn hiu sng vung. V t np qua hai in tr Ra, Rb cn x ch qua in tr Rb nn dng sng vung ng ra khng i xng vi thi gian mc cao th lu hn thi gian tx mc thp, hay ni cch khc dng sng c chu trnh lm vic, tc t s th/T trn 50%. Khith dng sng gn nh i xng, cnth chu trnh lm vic gn nh 100%. Tuy nhin gii hn ca Ra cng cn phi c lu . Nu khng cn phi c dng sng i xng ta c th cho 555 dao ng t tn s 1Hz n gn 1 MHz.Hnh 3.7 : Mch dao ng a hi phi n dng 555Hnh 3.8 : Dng sng ng raThi gian t np (ra cao): th = 0.693*(Ra + Rb)*C Thi gian t x (ra thp): tx = 0.693*Rb*CChu k tn hiu ra: T = th + tx = 0.693*(Ra + 2Rb)*CTn s tn hiu ra: ( )1 1.442 *a bfT R R C +Thit kRa: vi K n 10M, Rb: khng gii hn, C: t vi chc pF n 1000pF.+ Chn C = 1000pF; Ra = 1.5kf = 40Khz=> T = 1/f = 25 uST = th + tl = 25 uS. + Chn 1312hlt uSt uS'( ) 0.693 * 130.693 * 12h a bl bt R R C uSt R C uS + ' ( )63120.693 *12*1017.316*10 17.3160.693* 0.693*1000*10h a blbt R R CtR kC + ' ( )6 3 12' 3 31 163 3123 3 3113*10 0.693 17.316*10 *1000 *108.2*10 17.316*1013*1017.316*10 1.443*10 1.50.693*1000*1017.316 *10 8.2*10 9.116*10 10ab baRR R VR VRR kVR k + ' + + ' Chn: '11.58.2101000abR kR kVR kC pF ' V C C ( 5 V - 1 5 V )5 5 5 B12345678G N D T R I GO U TR E SC T R LH O L DD I SV C CR a1 . 5 K1 0 4V R 11 0 kC1 0 2V o u tR b '8 . 2 kHnh 3.9 : Mch dao ng 40Khz dng 5553.2.4Dao ng lp trnh t vi iu khin-T nhng phn tch trn ta thy rng cc mch dao ng u hot ng da vo in tr v t in mc thm bn ngoi quyt nh, nn khng c chnh xc v n nh cao, khc phc, mt phn t c chnh xc v n nh cao c dng, l tinh th thch anh, lc by gi ta c mch dao ng tinh th hoc mch dao ng kim sot bi tinh th thch anh, v d: Mch dao ng lp trnh vi iu khin. Mt lt mng c ct t khi tinh th thch anh theo chiu hng ph hp khi c kch thch s rung(dao ng) tn s chnh xc m rt n nh theo nhit v thi gian.3 3 p1 2 M h z3 3 pA T 8 9 C 5 11 81 91 0X T A L 2X T A L 1P 3 . 0 / R X DHnh 3.10 Mch dao ng lp trnh vi iu khinHnh 3.11 : Dng sng ng raThit kHnh 3.12 : Lu chng trnh to xung 40Khz3.2.5Mch cng sut phtYBeginSetb Xung 40KhzKhi to timer 1CPL Xung 40KhzTF1 = 1EndNU 3 C4 0 6 95 6C 50 . 1 u FU 3 A4 0 6 91 2U 3 F4 0 6 91 3 1 2U 3 B4 0 6 93 4T xU 3 E4 0 6 91 1 1 0Hnh 3.13 : Mch cng sut pht3.3 KHI X L TN HIU THU Bin t thu (sensor reciever) K hiu 400SRTnh nng Bin t thuTn s lm vic 40kHz nhy -63dB (0dB=10V/Pa)Gc m lm vic 80in dung 2550pF Nhit lm vic ti thiu -30C Nhit lm vic ti a 80C Khong cch d ti thiu 3 cm Khong cch d ti a 6 m phn gii 9 mm in p chu ng 20 VppBng 3.3 :Bng thng s bin t thu Nguyn l mch x l tn hiu thu - 1 2 VC 1 10 . 1 u F R 71 0 KR xD 24 1 4 8R 61 0 K R 1 11 0 KR 81 MR 91 0 0 K -+U 5 BL M 3 5 8567D 44 1 4 8-+U 6 AL M 3 5 832148C 1 60 . 1 u FR 1 01 M-+U 5 AL M 3 5 832148R 1 4+ 1 2 VR 1 21 0 KR 1 51 0 K U 7 C4 0 1 1891 0C 1 70 . 1 u FC 1 30 . 1 u FU 7 A4 0 1 1123147x u n g c h o tC 61 0 0 0 p+ 1 2 VR 1 3D 14 1 4 8+ 1 2 VC 1 20 . 1 u FK h a x u n g- 1 2 VU 7 B4 0 1 1564Hnh 3.14 : S nguyn l mch x l tn hiu thu3.3.1Mch khuch iC 1 10 . 1 u F R 71 0 KR 61 0 K R 1 11 0 KR 81 MR 91 0 0 KV o u t-+U 5 BL M 3 5 8567R 1 01 M-+U 5 AL M 3 5 832148R 1 21 0 K C 1 20 . 1 u FC 1 30 . 1 u F+ 1 2 V- 1 2 VHnh 3.15 : Mch khuch i tn hiu thu.Op amp:- Tng tr vo cao - p ng c v mt tn s.- H s khuch i cao.T cc yu cu trn nhm la chn mch khuch i dng Op amp lm b khuch i tn hiu thu.Xt tng khuch i th nht: y l mch khuch i o vi li 681 471010010VRAR Xt tng khuch i th hai: y l mch khuch i o vi li 6102 59101010VRAR li ton mch: 1 2* 100*10 1000V V VA A A 3.3.2Mch tch sngD 24 1 4 8D 14 1 4 8C 61 0 0 0 pV i n V o u tC 1 60 . 1 u FHnh 3.16 : S mch tch sngMch tch sng c tc dng chnh lu chm xung sau mch khuch i to mc in p dng khi c sng phn x.3.3.3 Mch khng ch+ 1 2 V- 1 2 VBD 44 1 4 8-+U 6 AL M 3 5 832148R 1 4+ 1 2 VR 1 51 0 KC 1 70 . 1 u FR 1 3K h a x u n gAHnh 3.17 : S mch khng chC nhim v khng ch khng cho tn hiu thu vo tng sau trong thi gian pht sng nhm trnh hin tng sng i trc tip t u pht vo u thu.Trong thi gian pht sng diode D4 lun dn lm cho op-amp lun bo ha dng bt chp tn hiu mch thu.in tr R13, R14 to p chun Vrf = 0.4V, tn hiu ng vos c so snh vi Vrf c ng ra l xung mc thp tng ng ti thi im nhn c sng phn x. ( )1313 14*0.4CCrfR VVR R +Chn R14 =1 M=> ( )( )614 313*10 * 0.435 *10 35,112 0.4rfCC rfR VR kV V Thit k: R13 = 33k + 2.2k = 35.2kHnh 3.18 : Dng sng ti cc ng vo ra b khng ch - 1 2 VBR 1 62 . 2 kD 44 1 4 8-+U 6 AL M 3 5 832148R 1 41 M+ 1 2 VR 1 51 0 KC 1 70 . 1 u FR 1 33 3 K+ 1 2 VK h a x u n gAHnh 3.19 : Mch khng ch sau khi thit k3.3.4 Khi o thi gian xung truynKhi ny hot ng nh mt flip flop to nn mt xung ko di trong sut thi gian sng i v v nh hnh v (D) vi cnh ln tng ng vi thi im pht xung v cnh xung tng ng vi thi im thu c chm xung phn x.Hnh 3.20 : Dng sng ti cc ng vo ra3.4THIT K B M3.4.1Mch to xung mTn s xung m ph thuc vo vn tc truyn sng trong mi trng, v phn gii ca php o.Hnh 3.21 : S mch to xung m o c khong cch x chm tia siu m phi i v v mt on 2x, vi vn tc V trong thi gian t. Khong cch cn o x cng l s xung m trong thi gian t. Vy tn s xung m: f = x/t, m t = 2x/V, nn 22x VfxV . thang o met: f = V/2 v V(m/s) thang o centimet: f = 100*V/2v V(100cm/s) thang o millimet: f = 1000*V/2v V(1000cm/s)Ti nhit 200C, ta c vn tc truyn sng trong khng kh l 343.5 m/sTa c tn s m thang cm: f =100*343.5/2=17175 Hz xp x 17 KhzChu k xung m: T = 1/17*103 = 58 sTa chn T = th + tl = 58 s vi th = tl = 29 s.S dng vi iu khin lp trnh.3.4.2 Mch m 0 255Do gii hn ca mch o nn yu cu b m ch nm trong gii hn 8 bit.Lu mch m:Chm tia phn x Chm tia ti Mt phn cch Khong cch cn o YYNNEndBeginInc BinmBit cho php = 1Hin th Xung cht caoHnh 3.22 : Lu mch m3.5 Khi hin th c im v cu to ca LED 7 on : Mt trong nhng loi n hin th thong dng, c s dng rng ri l n LED 7 onLed 7 on bao gm 7 ( hoc 8 on a, b, c, d, e, f, g ) ,led n c u song song vi nhau v c mt u chung. u c th l Anot hoc Katot xp theo hnh s 8 . Ty thuc vo t hp cc on c thp sang m ta c cc s v ch khc nhau. Gi s nh b v c sng s c s 1 , nu a,b,c,d,e,f,g cng sng th ta c s 8 .Hnh 3.23 :.Cu trc ca LED 7 onLed 7 on cng ging nh led n, in p chu ng c cng da vo c im mu sc ca chng .y l loi n dung hin th cc s t 0- 9. Khi mt t hp cc on chy sng s to c mt con s thp phn t 0 9.i vi led 7 on , ta phitnh ton sao cho mi on ca led c dng t 10 20 mA. Vi in p l 5 V th in tr cn dngl 330 .Vic thc hin mi mt con s l do mt led 7 on hin th do s dng phng php gii m ng nn ta thc hin giao tip gia VK Master vi led hin th nh hnh sau : trong mch ny th em s dng Led 7 on loi Ant chung.LED anot chungLED catot chungBng 3.4: Gi tr led hin tho Phng php qut led l phng php li dng hin tng lu nh v nhy kmca mt chng ta .o phng php ny ti mt thi im ch c 1 led sng , thi gian mi led sng khong t 50 100 us .S giao tip VK 89C51 vi Led 7 on theo phng php qut: Hnh 3.24 : S giao tip VK 89C51 vi Led 7 on.Cc on ca led ni vi nhau , 2 transister PNP lm nhim v cp ngun cho led . Nh vy,d liu ara cc on led , cc tn hiu qut led u tch cc mc thp . Ta c bng trng thi sau : S thp PhnM 7 on ( dng nh phn )M led 7 on(dng hexa )h g f e d c b a0 1 1 0 0 0 0 0 0 0C0H1 1 1 1 1 1 0 0 1 0F9H2 1 0 1 0 0 1 0 0 0A4H3 1 0 1 1 0 0 0 0 0B0H8051Port 0Port 1agagVcc4 1 0 0 1 1 0 0 1 99H5 1 0 0 1 0 0 1 0 92H6 1 0 0 0 0 0 1 0 82H7 1 1 1 1 1 0 0 0 0F8H8 1 0 0 0 0 0 0 0 80H9 1 0 0 1 0 0 0 0 90HBng 3.4 : bng trng thi cc led 7 on .3.6KHI NGUNS W 1 0C O N G T A CC 1 91 0 0 u FC 1 51 0 0 u FD 1 0L E DU 8 7 8 H T 1 21 32V I N V O U TGNDD 1 3L E DD 1 2L E DR 1 71 KC 1 01 0 0 0 u FR 1 02 2 0C 1 41 0 0 u FU 9 7 9 H T 1 213 2GNDV O U T V I NC 1 11 0 0 0 u F-+D 1 1B R I D G E2134J 1B I N T H 123U 1 0 7 8 0 51 32V I N V O U TGNDC 1 81 0 0 u FR 1 91 KHnh 3.25 S nguyn l khi ngun Vi iu khin: p 0 5V. Dng nh mc: 71mA Khi chun ha , to xung tn hiu in p + 12V ,- 12V dng nh mc l 0,5AT cc gi tr trn ta nhn thy cc IC n p h 78xx p ng c yu cu ca mch.3.7 : S mch nguyn l v lu gii thut3.7.1 : S mch nguyn l Mch nguyn l :A 3B 3C 3D 3E 3F 3G 3 A 3G3F 3E 3D 3C 3B 3A 3B 3C 3D 3E 3F 3G3A 3B 3C 3D 3E 3F 3G 3X T A L 21 8X T A L 11 9A L E3 0E A3 1P S E N2 9R S T9P 0 . 0 / A D 03 9P 0 . 1 / A D 13 8P 0 . 2 / A D 23 7P 0 . 3 / A D 33 6P 0 . 4 / A D 43 5P 0 . 5 / A D 53 4P 0 . 6 / A D 63 3P 0 . 7 / A D 73 2P 1 .01P 1 .12P 1 .23P 1 .34P 1 .45P 1 .56P 1 .67P 1 .78P 3 . 0 / R X D1 0P 3 . 1 / T X D1 1P 3 . 2 / I N T 01 2P 3 . 3 / I N T 11 3P 3 . 4 / T 01 4P 3 . 7 / R D1 7P 3 . 6 / WR1 6P 3 . 5 / T 11 5P 2 . 7 / A 1 52 8P 2 . 0 / A 82 1P 2 . 1 / A 92 2P 2 . 2 / A 1 02 3P 2 . 3 / A 1 12 4P 2 . 4 / A 1 22 5P 2 . 5 / A 1 32 6P 2 . 6 / A 1 42 7U 2A T 8 9 C 5 1C 13 3 p fC 23 3 p FX 1CR Y S T A LC 31 0 u FR 11 0 kA 1B 1C1D1E 1G 1F 1CA2L E D 1A 1B 1C 1D 1E 1G 1F 1CA2L E D 2Q 1MP S A 6 5Q 2MP S A 6 5R 22 . 2 kBC BR 43 3AR 32 . 2 k12J 2S I L - 1 0 0 - 0 2A 1B 1C1D1E 1G 1F 1CA2L E D 3AQ 3MPS A 6 5R 52 . 2 kC12J 3S I L - 1 0 0 - 0 21234567J 1S IL - 1 0 0 - 0 71234567J 4SI L - 1 0 0 - 0 7t r a n A 1 0 1 5+ 5 vS R F 0 5 Nguyn l hot ng : B vi iu khin nhn cc tn hiu t mi trng bn ngoi thng qua b bin i, c s dng thu d liu. Cc my tnh s ch s dng gi tr thp phn, nhng trong thc t l cc i lng vt l nh : vn tc, nhit , p sut..; Do , cn c b bin i chuyn cc i lng vt l thnh cc tn hiu in hoc in p, cc b iu khin c th c coi nh l cc cm bin. Cc cm bin c th cho ra tn hiu dng dng in hoc in p dng lin tc. 3.7.2 : Lu gii thut EndHin th LEDBeginKhi to LEDClrBitRx Ngng b mChuyn s m sang BCDPht xung v kha b thuKhi to vng nh lu tr d liu hin thBitRx = 1BCD to ASCIIBitRx = 0Giai o 1Mode= 1Giai o 2N YNYNYHnh3.26 :Lu o khong cch3.8 : Chng trnh ;CHUONG TRINH DO AN TOT NGHIEP;MAY DO KHOANG CACH UNG DUNG SONG SIEU AM;SVTH: Tran Huu Chung RS BIT P2.3RW BIT P2.4E BIT P2.5LEDDATA EQU P0 ;DU LIEU LEDLOP BIT P1.0 ;LOCK PULSE COUNTERMODE BIT P2.7 ;CHON DAI DOINTR BIT P2.2WRT BIT P2.1RED BIT P2.0KEY1 BIT P1.2 ;DO KHOANG CACH THEO TRUYEN SONG CUA BIEN TUKEY3 BIT P1.4 ;HIEN THI TAN SO XUNG DEMBITRx BIT P1.1 ;LATCH PUSE COUNTER 4kHzLLP BIT P2.6 ;LATCH LED PULSE;***************************************************************************************************BUFFPRO EQU 30H ;THANH GHI DEMORG 000HLJMPKHOITAOORG 030HKHOITAO:MOV TMOD,#01HMOV BUFFPRO,#0 ;XOA THANH GHI DEMSETB KEY1SETB KEY3CLR LLP ;CHO PHEP HIEN THI LEDCLR LOP ; KHOA BO DEMCLR MODECLR BITRxLCALL KTLED ; KHOI TAO LEDMAIN:LJMP MAIN;#####################################################################################################;##########################################CHUONG TRINH PHIM 1 #####################################;#####################################################################################################CTKEY1:CLR LOP ;XUNG DIEU KHIEN PHAT_DD0: MOV R5,#125 ;TAN SO XUNG 4kHzDJNZ R5,_DD0CPL LOP ;CHOT BO THUSETB TR0SETB BITRx_DD1: MOV R5,#125DJNZ R5,_DD1CLR LOP_DD10: MOV R5,#0FFHDJNZ R5,_DD10CLR BITRxJB BITRx,$CLR TR0MOV R7,TH0MOV R6,TL0JNB MODE,_DD2 ;KIEM TRA MODEMOV B,#6MOV A,#0C0H ;THONG BAOLCALL GHIMADKLCALL DELAY40MSMOV DPTR,#_MODE0MOV R3,#16TB0: CLR AMOVC A,@A+DPTRLCALL GHIDATALCALL DELAYINC DPTRDJNZ R3,TB0JMP _DD3_DD2:MOV A,#0C0H ;THONG BAOLCALL GHIMADKLCALL DELAY40MSMOV DPTR,#_MODE1TB1:MOV R3,#16CLR AMOVC A,@A+DPTRLCALL GHIDATALCALL DELAYINC DPTRDJNZ R3,TB1MOV B,#60_DD3:MOV B,#1LCALL DIV16_8 ;DOI XUNG RA KHOANG CACH (CM)MOV B,#10LCALL DIV16_8 ;CHUYEN SANG MA BCDMOV 10H,B ;HANG DON VIMOV B,#10LCALL DIV16_8MOV 11H,B ;HANG CHUCMOV B,#10LCALL DIV16_8MOV 12H,B ;HANG TRAMMOV B,#10LCALL DIV16_8MOV 13H,B ;HANG NGANMOV B,#10LCALL DIV16_8MOV 14H,B ;HANG CHUC NGANMOV B,#10LCALL DIV16_8MOV 15H,B ;HANG CHUC NGANMOV R2,#5MOV A,#80HLCALL GHIMADKLCALL DELAY40MS_DD4: MOV A,#' 'LCALL GHIDATALCALL DELAYDJNZ R2,_DD4MOV R1,#15H_DD5: MOV A,@R1ADD A,#30H ;CHUYEN MA ASCIILCALL GHIDATALCALL DELAYDEC R1CJNE R1,#0FH,_DD5MOV A,#89HLCALL GHIMADKLCALL DELAY40MSMOV A,#'C'LCALL GHIDATALCALL DELAYMOV A,#8AHLCALL GHIMADKLCALL DELAY40MSMOV A,#'m'LCALL GHIDATALCALL DELAYMOV R2,#5MOV A,#8BHLCALL GHIMADKLCALL DELAY40MS_DD6: MOV A,#' 'LCALL GHIDATALCALL DELAYDJNZ R2,_DD6RET;##################################################################################################;######################################## CHUONG TRINH PHIM 3 ####################################;##################################################################################################;****************************************PHIM MODE ************************************************CTKEY3:CPL MODERET;##################################################################################################;###################################### CHUONG TRINH CON ########################################;#################################################################################################;************************************** KHOI TAO LED **********************************************KTLED:MOV A,#38HLCALL GHIMADKLCALL DELAY40MSMOV A,#38HLCALL GHIMADKLCALL DELAY40MSMOV A,#0CHLCALL GHIMADKLCALL DELAY40MSMOV A,#01HLCALL GHIMADKLCALL DELAY40MSRET;************************************** XOA MAN HINH ***********************************************XHT: MOV A,#01H ;DELAY 6uSLCALL GHIMADKLCALL DELAY40MSRET;************************************** GHI MA DIEU KHIEN LED **************************************GHIMADK: ;DELAY 5uSMOV LEDDATA,ACLR RSCLR RWSETB ECLR ERET;************************************** GHI MA DU LIEU LED *****************************************GHIDATA: ;DELAY 5uSMOV LEDDATA,ASETB RSCLR RWSETB ECLR ERET;************************************* HEX TO BCD CONVERTER *****************************************HEXTOBCD: ;DELAY 28uSMOV B,#10DIV ABMOV 13H,BMOV B,#10DIV ABMOV 14H,BMOV 15H,AJZ EXIT0 ;CHUONG TRINHXOA 0ADD A,#10HMOV 15H,AMOV A,14HADD A,#10HMOV 14H,AJMP EXIT1EXIT0: MOV A,14HJZ EXIT1ADD A,#10HMOV 14H,AEXIT1: RET;************************************* HIEN THI LED *************************************************HIENTHI:DIS1:MOV A,R0 CALL GHIMADKCALL DELAY40MSMOV A,@R1ADD A,#20HLCALL GHIDATALCALL DELAYINC R0DEC R1CJNE R1,#13H,DIS1MOV A,R0LCALL GHIMADKLCALL DELAY40MSMOV A,@R1ADD A,#30HLCALL GHIDATALCALL DELAYINC R0DEC R1DIS0: MOV A,R0LCALL GHIMADKLCALL DELAYMOV A,@R1LCALL GHIDATALCALL DELAYINC R0DEC R1CJNE R0,#8BH,DIS0RETHIENTHI2:DIS12: MOV A,#080H CALL GHIMADKCALL DELAY40MSMOV R0,#5HT200: MOV A,#' 'CALL GHIDATACALL DELAYDJNZ R0,HT200MOV A,@R1ADD A,#20HLCALL GHIDATALCALL DELAYDEC R1MOV A,@R1ADD A,#20HCALL GHIDATACALL DELAYDEC R1MOV A,@R1ADD A,#30HCALL GHIDATACALL DELAYMOV A,#'o'CALL GHIDATACALL DELAYMOV A,#'C'CALL GHIDATACALL DELAYMOV R0,#6HT201:MOV A,#' 'CALL GHIDATACALL DELAYDJNZ R0,HT201RET;############################# CHIA 16 BIT ##########################################################DIV16_8:PUSH02HPUSHACCMOVR2,#16CLRADEVICE:XCHA,R6CLRCRLCAXCHA,R6XCHA,R7RLCAXCHA,R7RLCAJNC _X1CLR CSJMP A_GREATER_EQ_B_X1:CJNEA,B,NOT_EQUALSJMPA_GREATER_EQ_B NOT_EQUAL:JCBELOWA_GREATER_EQ_B:SUBBA,BXCHA,R6ORLA,#1XCHA,R6BELOW:DJNZR2,DEVICEXCHA,BPOPACCPOP02HRET;#####################################################################################################;############################# CHUONG TRINH DELAY ####################################################;####################################################################################################DELAY40MS:MOV 70H,#10DEL0:MOV 71H,#0FFHDJNZ 71H,$DJNZ 70H,DEL0RET;*****************************************************************************************DELAY:MOV 7EH,#50DEL1:MOV 7FH,#50DJNZ 7FH,$DJNZ 7EH,DEL1RET;*****************************************************************************************DELAY50:MOV 7EH,#1DEL2:MOV 7FH,#25DJNZ 7FH,$DJNZ 7EH,DEL2RET;*****************************************************************************************DELAY1S:MOV 70H,#10DEL3: MOV 71H,#100DEL4: MOV 72H,#100DJNZ 72H,$DJNZ 71H,DEL4DJNZ 70H,DEL3RET;*********************** DELAYDEM ********************************************************; DELAY10MS:MOV R5,#10DEL5: MOV TMOD,#01HMOV TH0,#HIGH(-1000)MOV TL0,#LOW(-1000)SETB TR0JNB TF0,$DJNZ R5,DEL5RET;*****************************************************************************************DELAYS:MOV 70H,#10DEL6: MOV 71H,#100DEL7: MOV 72H,#100DJNZ 72H,$DJNZ 71H,DEL7DJNZ 70H,DEL6RET;########################################################################################;############# TAO VUNG DU LIEU #########################################################;########################################################################################_MODE0: DB 'GIAI DO CENTIMET'_MODE1: DB 'GIAI DO MILLIMET'TEN: DB 'Tran Huu Chung'TUA: DB 'MAY DO CU LY'_0C: DB ' V = 331.5 m/s '_10C: DB ' V= 337.5 m/s '_20C: DB ' V = 343.5 m/s '_30C: DB ' V = 349.5 m/s '_40C: DB ' V = 355.5 m/s '_50C: DB ' V = 361.5 m/s 'ENDPhn 3 : Kt lun v kin ngh .A KT LUNQua thi gian nghin cu v thc hin ti THIT K V THI CNG MY O KHONG CCH NG DNG SNG SIU M nhm thc hin t c cc kt qu sau: Cm bin siu m SRF05 l loi cm bin c cu thnh t hai b phn : b phn pht sng m v b phn thu sng m. ng dng ca SRF05 c s dng rng ri, dng nhn bit cc vt trong khong cch t 3cm n 4m v o khong cch ca vt. c tnh vt tri ca SRF05 l ch 2. Cm bin siu m SRF05 c kh nng kt ni vi vi iu khin 8051 to thnh vi mch iu khin, ng dng ca kh ny c s dng trong mt robt d ng trnh chng ngi vt v o khong cch.Trong cng nghip cc cm bin siu m cng c th gp phi nhiu sai xt do mi trng ngoi tc ng ln cm bin, do vy cn c nhng b phn x l tn hiu t cm bin.Ngy nay, ngi ta vn tip tc nghin cu v pht trin vic ch to cc robot c gn cm bin siu m ng thi vi cc cm bin khc nh laser, camera kt hp vi cc cng ngh ca vin thng nh GPS, GSM nhm nng cao chnh xc trong vic nh v cng nh thm d mt khong khng gian no xy dng bn .B.Kin ngh Vi thi gian thc hin ti tng i ngn nn ti khng th trnh khi nhng sai st mch thi cng cha t c ng theo yu cu nhm thc hin hy vng vi thi gian sau ny nhng hn ch ca ti s c khc phc trong cc nhm sau.Do kin thc chuyn mn, thi gian nghin cu v kinh nghim thc t cn hn ch nn mch thi cng cha p ng c yu cu ra ban u. Nhm thc hin rt mong c s ng gp kin t qu thy c, bn b, v nhng ngi quan tm n ti ny ti c hon thin hn.Em Xin Chn Thnh Cm n !C. Ti liu tham kho o Nguyn Tng Cng , Cu trc lp trnh h VK 8051 . NXB Khoa hc v kthut.o Lng Ngc Hi , Gio trnh k thut Xung S . NXB gio dc. o Sonar faq, srf05tech,Application_Note_Ultrasonico HANS P. MORAVEC, Sensor Fusion in Certain,Grid for Mobiles Robotso Cc trang web tham kho: ant7.com, acroname.com, hobbyengineering.com, cpu.word.com, metechvn.com, robotics.com.