MOT SO GIAI PHAP XAC DINH SAI LECH SONG SONG TRUC QUANG CUA CAC THIET BI QUANG HOC
Nguyen Manh Tudn, Pham Hoai Anh
Trung tdm Do luong. Cue TC-DL-CL, Bg Qudc Phdng Torn tdt:
Ddi ydi cdc thiet In quang hge dang .sir dung trong qudn dgi, mgt trong nhung thdng sd ky thudt rdt quan trgng can phdi ddm bdo chinh xdc Id true quang ciia nd. Cdc logi kinh ngam cd mgt dng kinh khi gdn len vu khi, true quang ciia kinh ngam cdn phdi song song vol true ngam cua vu khi. Cdn doi voi thiet bi quan sdt, mdy do xa La.ser cd hai dng kinh, yeu cdu true quang ciia hai dng kinh phdi song song voi nhau. De kiem tra vd hieu chinh thdng sd ky thudt ndy ciia cdc thiet bi, cdc don vi hien dang duac trang bi cdc thiit bi kiim tra vd hieu chinh quang hge chuyen dung (phuong tien do quang hge). Tuy nhien cdc thiet bi ndy cdn chua du, chua dap iirng duoc het nhu cdu kiem tra ddi voi cdc thiet bi quang hge, nhdt la cdc logi mai.
Khdc phuc tinh trgng thieu thiet bi kiem tra chuyen dung, trong nhung nam qua phdng Chudn quang hoc thugc Trung tdm Do luong Qudn dgi da nghien ciru vd dua ra nhieu gidi phdp de do thong sd ky thudt ndy cho nhieu logi thiet bi quang hge khdc nhau. Trong bdi bdo
ndy trinh bdy mgt sd gidi phdp mdi diccjc nghien ciru dua vdo dp dung.
Abstract:
For optical devices used in military, one very important specification is the accuracy of their optical axis. The viewfinder that has one lens when mounted on the weapon, the viewfinders optical axis should be parallel to the axis of sight of the weapon. Also for observational equipments and Laser Rangefinder with two lenses, the optical axes of lenses are required parallel to each other. To check and calibrate specifications of the equipment, the workstation is being equipped with testing equipment and specialized optical calibrators (optical measuring devices). However, these devices are still not enough to meet all the needs for testing optical instruments, especially new types.
To overcome the lack of specialized testing equipment, in recent years Optical Standard Unit at the Military Center for Metrology has studied and proposed various solutions to measure optical axis for a variety of optical devices. This paper introduces some newly studied solutions that liavejust been put into application.
I. Xac dinh sai lech true quang dng chuan trixc va true ca cua co cau ga kinh ngam cua may kiem tra va hieu chinh kfnh ngdm xe tang tO-TLU-CT
1.1. Gidi thieu
May kilm tra vd hidu chinh kinh ngdm xe tang lO-TLLl-CT (may IO-TLU-CT)la phuang tidn do quang hge do Nga chd" tao, nd cd cdng dung dimg dd' kid'm tra va hidu chinh cac kinh ngdm phao thii lap trdn xe tang.
Khi tie'n hanh kie'm dinh may lO-TLU-CT, mdt trong cdc thdng s6' ky thudt cin phai do ludng xac dinh la do sai lech true quang d'ng chnin true ciia may theo hai chieu t^m va hudng, vdi ydu cSu dd chfnh xac cu thi:
Dd sai lech song song true quang d'ng chuin true so vdi mat phang ngang khdng dugc Idn ban 3,6' (dd chi'nh xac true quang theo tdm);
True quang d'ng chuin true phai vudng gdc vdi true ndi 2 ngoam chu' "V", diing de' ga Idp kinh ngdm xe tang TLU, sai lech cho phep khdng Idn ban 3,6' (dd chinh xac true quang theo hudng).
1.2. Plunrng phiip dii iip dung (rude day:
Dc Xiic dinh do khong .song song tiiic qiuing dng cluian true so vdi nia( plu'iiig ny;iiio,|j ihc su dung m;iy kinli vT ck- do iniv licp.
Vdi yen can llui' h;ii ihi irud'c da\' clur;i ci) phuo'iig phiip iiiio cic Xilc dinh iiiol CiiclicJi .\;ic Dc kiem lia. hicii chinh liiic ciiiaiig ong chuan true iheo lui'd'ng, la diing mot kiiih iigiin, iiuig phao ihii claiiL: sir clung lot lam cluuin. Tuy nhien khdng xiic dinh dugc chfnh Xiicdo loch Iruc ciuaiiLi la b;io nhieu va lioni' iii'U)'cii lac do ludng ciing khdng sir dung dugc phi/n phiip iiiiy, uic hi dung plurong lien do c'(') do chfnh x;ic ihiip hon liim chuiin cho phuong tjcnl cd do chfnh x;ic c;io hon.
1.3. Phuong phap mdi
Xui'it phiil ur nhu'ng khd khiiii iiiiy, cluing loi dii nghien ciru va tim ra phuang phapmdiiri CO' sd sir dung ciic plurong ti^ii do, chuan miiu hicn cd de' xac dinh sai lech true quangoi cluian true ciia m;iy; sir dung bd do ga cci dinh cd giin dng ngilm cbuiiii vudng gdc voiii chuiin cua niiiy do gdc viin ni'mg lOf hicn dang cd tiii phdng, ga liip tru chuan ciing 6'ngng^
len 2 ngoam chu "V" d6 tiio ra true ngiim chuiin vira cd thd' kie'm tra ddng thdi do songsoi|
true quang ciia dng chuan true miiy 10-TULI-CT so vdi mfit pbiiiig ni"im ngang vii do vuongjo giira true quang dng chiuin true vdi Iruc ndi 2 ngoiim chir "V" ga Idp kfnh ngdm phao thul
tiing.
Hinh 1. So do ga Idp dimg de do xac djnh sai lech true quang ong chuan trircini kiem tra va hieu chinh kinh ngam xe tang K)-T11J-CT
1- Ong chudn true may fO-TLU-CT; 2- Ngoam chir "V" ga kfnh ngdm; 3- thanh n^H may W\ ; 4- gia cd dinh; 5- dng chuan true may lOf
c u -^ ^^^ !""?" '""'^ """^ "'""'"^ °"^ "^^"^ '^''"^'" "^^y ^o goc »0r vdi mat phdng ndm nga chuan uim) dugc thiei lap bang may kinh vT cd do chfnh xdc de'n 30" Khi nay ta sH^
them Chan da phu, cd the dieu chinh do cao dd nang ha d'ng chuin true theo tdm
Do vudng gdc giua true quang dng ngdm chuin va tru chuin eua may do gdc van nang lOr, dugc thie't lap cung bang may kinh vT cd dd chfnh xac 30" khi gdn tren miiy do gdc fOf
Nhu vay true quang cua dng ngdm chuiiii da dugc thiei hip cii iheo tiim va hudng vdi do chfnh Xiic den 30" Giiii phap nay hoan loan phii hgp vdi yeu cilu v^ chuan dimg de Iruydn chuin trong do ludng va giiip chiing ldi khiic phuc dugc virdng niiic trong qua trinh kiem dinh may kie'm tra va hieu chinh kfnh ngam xe tang lO-Tlil-CT Giai phap cho phep ta xac dinh dong thdi do sai lech true quang ciia d'ng chuin true theo ca tt1m, hudng va cung rdi thuan tidn cho vide hieu chinh may trong qua trinh sua chua.
II. Xac dinh .sai lech song song true quang ciia thiet hi kiem tra kinh ngam chi huy YO- T3K
2.1. Gidi thieu
Tliie't bi kiem tra, hieu chinh kfnh ngdm chi huy I0-T3K (may K)-T3K) dugc dung de kie'm tra dd song song true quang ciia cac 6'ng kfnh quan sat kfnh chi huy T3K. May I0-T3K gdm cd 3 dng chuin true ndm Idch nhau khdng trdn ciing mdt dd cao, 2 d'ng chuin true ndm phfa dudi diing di lam chuin kie'm tra dd song song cua 2 6'ng kfnh quan sat, I d'ng chuin true nam phfa tren diing de lam chuin cho dng kfnh quan sdt cua chi huy. 3 true quang ciia cdc dng chuin true each nhau khoang 300 mm.
Do cac dng chuin true khdng ndm tren cung mdt dd cao va khoang each giira chiing khdng Idn, nen ta khdng thi dp dung phuang phap xac dinh dd sai Idch song song nhu ddi vdi may kilm tra va hieu chinh phdo ddi kfnh 5C-2M.
2.2. Phuong phap trudc day
Trudc ddy dl kilm tra dd song song true quang cac d'ng chuin true cua may 10-T3K ngudi ta sii dung 1 kinh ngdm ehl huy dugc ggi Id chuin bode bang muc tieu rd't xa ngodi thue dia.
Phuang phap tren ddy mang nhilu dinh tfnh, chi phii hgp cho viec hieu chinh may. Do chfnh xac cua phuong phap tha'p, cd nhieu ye'u td anh hudng den ket qua do.
2.3. Phuong phap mdi
Sir dung may kinh vi k^t hgp vdi mdt lang kinh hinh binh hdnh dugc lap len bd do ga di xac dinh dd song song true quang ciia tCmg cap dng chuin true. Khi true quang cua 2 dng chuin true song song vdi nhau, tdm chir thdp kfnh vach khac ciia ca 2 d'ng se cho ta nhu 1 muc tieu d xa vd ciing. Dat may kinh vl tai mdt vi tri, tie'n hdnh do gdc tim, hudng true quang cua tiing dng chuin true se cho ta cac gia tri gdc nhu nhau. Cdn ne'u true quang cua cac d'ng chuin true khdng song song cac gia tri gdc tdm, hudng do dugc se lech nhau. Tren ca sd dd ta cd thi tfnh toan xac dinh dugc d6 sai lech song song true quang ciia timg cap d'ng chuin true.
Dudi ddy Id vi du cu thi d l xdc dinh sai lech song song true quang cua dng chuin ben phai va ben trai:
Ga dat may kinh vl phfa trudc vdt kfnh ciia hai dng chuin true cin kilm sao cho true quang ciia nd each dlu true quang cua hai dng chuin true;
- Cdn bdng may kinh vl, dilu tieu vdt kfnh ve vi trf '*«»";
Ngdm qua may kinh vi, sur dung ke't hgp lang kfnh hinh binh hanh, bit anh kinh vach khac dng chuin true ben phai;
- Sir dung mim dilu chinh tdm hudng may kinh vT dua triing hai tdm chir thdp kfnh vach khdc may kinh vi vd dng chuin true ben phai;
Dgc gid tri gdc tdm /?„ va gdc hudng Ofi tren may kinh vT, ghi vdo bien ban kilm dinh theo mdu phu luc A;
Tie'n hdnh tuong tu khi ngam vdo d'ng chuin true ben trai, dgc gdc tdm y^L ^^ S°^ hudng o^
tren may kinh vT, ghi vdo bien ban kilm dinh theo mdu phu luc A;
Dd sai lech song song true quang cua dng chuin true ben phai va ben trdi dugc xdcdinh theo cdng thdc 1.
A, = V ( A - - A , ) ' + ( ^ A ' - ^ / . ) ' (1) iron" eld: • V do sai Icch song song true qu;ing ciiii dngchuilln IrUc ben phiii Vii bin
t i i i i : ^ , - I •>•
/ii^, (/,, giii In gdc lain, hudng true quang ciiig chudn true ben phai;
/?,, (/., gia tri gdc lam, hudng true quang dng chudn true ben trai.
HI. Xac dinh do lech song .song ciia hai true quang may do xa la.ser 3.1. Dat van dc:
Trong Ciic phdn tren ciing nhu trong bai biio dimg trong "Tuydn tdp bao cao khoa hoc" Hoi iighi khoa hoc ky thuiit do ludng toiin qudc xuitl biin iii'im 2005 da trinh bay mdt sd phuong, phiip Xiic dinh dd song song ciia cac true quang cua ciic phuang tien do quang hge. Cac true j quang nay giin nhu dfiu cd dac ifnh nhu nhau va diu thu hoae xiic dinh dugc bang cac phuong tien do quang hinh thdng dung.
Ddi vdi niiiy do xa Laser, hai true quang cdn xac djnh dd song song lai cd tfnh chit khac nhau: mgt la true ngdm quang hge cd tfnh chdi nhu cac true quang hinh bgc da dugc dl cilpo trSn va trong bai biio UUde diiy; hai Ui true tia Laser cd budc sdng bdng ngoai khdng nhin th2iy bang milt thudng (thudng tir 1,06 pm deii 1,7 pm).
Tren hinh 1 la so dd quang cua miiy do xa Laser LRB 25000 do Canada chd tao. May nay cd kha nang do xa tdi 25 km vdi do chfnh xiic II 5 m, sir dung Laser cd budc sdng 1,54 pm.
Cd the giai thfch tdm tdt nguyen ly boat ddng ciia miiy do xa Laser theo so d6 hinh 2 nhir sau:
Khi phat lenh do tir phfm dieu khien 3, may se dieu khiln khdi thu phat 4 phat xung START de dilu khien Laser 11 phat tia Laser qua dng Tdie 12, kfnh dieu chinh 13 tdi muc tieu, dong thdi ghi lai thdi dilm xudt phat (START) ciia tia Laser. Chiim Laser di tdi muc tieu se phan xa lai, dugc vat kfnh 8 thu lai, qua ldng kfnh 7 dua vl dlu thu 4, ddu thu 4 nhdn tin hieu phan xa, tao xung STOP va truyen tfn hieu tdi khdi 3 do thdi gian vd tfnh ra khoang each hien thi len man hinh sd 2, ta cd the quan sdt d thi kfnh I. Kfnh vach khdc 6 dugc dat tai tifiu cu vdt kfnh 8 vd cd thi quan sat bdng thi kfnh 5. Dudng ndi tdm kfnh vach khdc 6 (giao di^ni vach khdc chir thap) vd tdm vat kfnh 8 tao thdnh true quang ciia kfnh ngdm muc tieu, d6ng thciij cung la true quang ciia dau thu chiim tia laser phan xa. (Thiet ke nay giam bdt viec dieu chinli de 2 true quang kfnh ngdm va dau thu triing nhau). True quang cua chiim Laser phat trong h^
thdng nay chii ye'u do dng Tele 12 quydi dinh va cd thi dieu chinh tinh qua cdc kfnh hinh ngra 13. Vdi dng Tele 12 chiim Laser phat dam bao dugc do song song cao (khdng bi loe ra nhufl cac Laser ban ddn dung trong cac may do xa cu ly ngdn).
Yeu cdu la 2 true quang ciia chiim Laser phat vd true quang ciia kfnh ngdm phai song song vdi nhau. Neu khdng thoa man yeu ciu dd thi bode may do khdng chfnh xac, hodc khdng do dugc. Khi sai lech Idn, chiim phat hudng tdi vdt khdc vdi vdt dugc ngdm, ngodi ra thdnh phin phan xa chfnh la phan xa guong theo dinh ludt Dl Cac se khdng quay lai vl hudng may do.tui hieu thu ed thi nhd khdng bdt dugc, khi dd khdng do dugc. Nd'u nhu sai lech nhd, tin W phan xa vdn thu dugc, tuy nhien ket qua do xa la khoang cdch tdi vdt dugc chilu bdi chim Laser phat chir khdng phai tdi vat dugc ngdm, khi dd kd't qua thu dugc se sai.
J
^if-
^
Hlnh 2. So do khdi cua mgt mdy do xa Laser LRB 25000
I- Thi kfnh man hlnh sd; 2- Man hinh sd; 3- Mdn hinh va khdi dilu khiln; 4- dau thu chiim phan xa; 5- thi kfnh ngdm muc tieu; 6- Kfnh ludi chir thdp; 7- Lang kfnh; 8- Vat kfnh chung cho dlu thu va kfnh ngam muc tieu; 9- Kfnh bao ve; 10- ldng kfnh doi hudng xung START;
II- Dlu phdt Laser; 12- d'ng kfnh Tele; 13- Kfnh chinh true quang tia phdt Laser; 14- Khdi ngu6n dien; 15- Khdi phfm dilu khiln nhanh.
3.2. Giai phap kiem tra
Phuang phap kilm tra dugc md ta tren sa do d hlnh 3:
Siir dung phuang phdp kilm tra kilu Calip dl kilm tra. Yii thue hien cac phep kilm tra ta cin che' tao cac Mia kilm tra (tucng duang cac dudng kilm tra diing trong do ludng ca khO khdng khd khan gi: bang bia gidy trdng hodc mica trdng hinh trdn, khdc vach chir thdp vdi tdm la tdm hinh trdn nhu trong hinh 4. Ga mia ddi dien vdi may do xa can kilm tra sao cho cdch ly cac vdt cd thi gdy nhilu (kl ca chdn ga, co thi che tao chdn chuyen dung) vd each may do xa cin kilm tra mdt khoang bdng L. L cd thi chgn bdng 100 m hay 200 m,v.vl I
Ta CO thi dung may do xa chuin dl thie't Idp gia tri L, dl dam bao dd chinh xac cao cdn dat may do xa chuin tren chdn hodc ban vOng chac vd cd dinh vi tri ddt may. Kich thudc dudng kfnh mia la D: Tuy vdo ydu ciu vl dd chfnh xdc song song 02 true quang ma ta xac dinh gid tri kfch thudc D. Vi du yeu ciu 02 true quang cd sai lech true quang khdng qud 1', khi dd theo so d6 hlnh 3, vdi L= 100 m, ta cd thi tfnh:
D_
2L = tan/?=tan{r) (2)
D = 2Lxtan(r) = 200x0.00029088 = 0.0582[m] = 58.2[m/7j] (3)
D.
Hinh 3. So dd kidm tra cac true quang may do xa La.ser 1- niiiy do xa La.ser; 2- Mia kiciu Ira hlnh lion cd dudng kfnh D;
L — khoiing each tir may do xa ddn Mia 2; P - gdc lech giu'a true quang tir niiiy do xa deii tdm Mia 2 va true quang tir miiy do xa dd'm cp Mia 2
Mia
Vach da'u lam
Hinh 4. Mia kiem tra co dudng kfnh D va vach dau tam Mia ch& thap de co the ngam chfnh xac b^ng dng ngdm xac djnh diem do cua may do xa.
Sau khi xdc dinh khoang cdch L bdng may do xa chuin, bd mdy chuin ra thay vao do miy do xa cdn kiem tra song song true quang, tie'n hanh ngdm vdo tdm mia d l do khoang cachtif may do xa den mia Neu kit qua do xa gin vdi ket qua do bdng mdy chuin, sai sd nhd hon sai so cho phep cua mdy thi khi dd mdy vira dat yeu ciu vl dd chfnh xac do xa d cu ly L vita dat yeu cau ve dd song song cdc true quang cin kilm tra. . J ^ •
3.3. Phuang phap do do lech hai true quang
Cdch 1dm tuong tu nhu tren, thay vi ga may do xa cin kilm tra Idn chdn hay bdn cd dinh, t eu fn r Y l ''I ^ ' ' ' • "^^^^ ^ " " S "^'^ ^° •^'^h thudc Idn han dl d l xde dinh muc br'chfnh x a L ' h " h T'l"^ ^ " ' ^'^"^^ "^^' ^^"h ^^"g D '"^^y '^- "^i- ^inh trdndlda.
X X d r . 6 lech cT l ° - ^ " ' " ' " ^ ' ? ^ ' ' " ^ ^ ^ ^^' ^^"^ ^' '"^^ ^'^^ '^^ ^^^- -hum Laser t t ' c h o n D - ^n^-p V i'" w ' T ' " ^ ^ ^ ' " ^ ^ § ^° 'l"^ ^hi cdng kinh, khdng tien diing. C6 c^c . ^ " ech". u" ai';^^ ' ' ' t ^ t ' "'^"^ ^^' niia L = 100 m thi cd thi do duoc thuin M
(p--2im\-\(DI2L) = artan( 1/200) = 1 7 ' (4)
Sau khi xac dinh khoiing each tir niiiy do xa deii mia lai diein ngdm la tdm mia, quy "0" gdc lien thiei bi do gdc, ta tu' lir quiiy bg phiin ga niiiy do xa cua may do gdc lech ddn vl phfa trai bang dia quay gdc hudng cho de'n khi gia tri do xa hien ircn may do xa cd sir thiiy doi dot bien, khi dd chiim Laser phat ra ngoai mia, ghi lai giii trj gdc tren may do gdc aT. Thue hien tuong tu khi quay may sang phai ta xac dinh dugc gdc aP. Cd the dd nhdn thdy rdng: diem giua a T vd a P chfnh Id hudng cua chiim Laser phdt khi kfnh ngdm ngdm vdo tdm mia. Khi aT va aP cd gia trj bdng nhau Ihi hudng ciia chiim phat Laser triing hudng true ngiim. Ga may do xa ndm ngang ( quiiy 90° quanh true ngtim) r6i tiln hdnh qudt gdc nhu Udn ta xac djnh dugc cac gdc lech tren aTr va dudi aD.
Khi dd gdc lech giua hai true quang ciia may do xa Laser c6 thi tfnh:
Lech theo hudng (chi'nh bdng gdc hudng ciia chiim Laser chie'u):
/?H = «P Q T (5)
Lech theo tim (chfnh bdng gdc tim ciia chum Laser chie'u):
y5r = CcTx - cD (6) Do chfnh xdc do gdc dat dugc khi dung mdy do gdc lOF Id 1', ne'u diing may do gdc rC-2 thay ciio lOT thi cd thi dat dd chfnh xdc tdi 2"
IV. Ket luan
Viec xac dinh, kilm tra dugc sai lech ciia cdc true quang cd y nghia rd't quan trgng: vi sai lech song song true quang cua cdc kfnh ngdm nhu dng nhdm, kinh chi huy cd thi ddn tdi viec nhin mdt hinh thdnh hai, ne'u lech nhd cd thi gdy mdi mdt, khd chiu ddi ydi ngudi dung; sai tim vd hudng cua kfnh ngdm se ddn tdi ngam sai; vdi cac may do xa Laser, sai song song true quang d muc nhd cd thi ban che' tim do xa, mdc Idn cd thi Idm mdt kha ndng do ciia thiet bi.
Trong nhihig ndm gin ddy da cd nhiing cdng trinh nghien cuu che" tao mdy do xa, nhung viec do kilm tra dd song song cua cac true quang chua cd thiet bi chuyen dung gap kho khan. Neu khong phat hien sai Idch ndy cd thi khd khdn trong cdn chinh, cd thi ddnh gia sai ddi vdi cdc chi tie't khac: vf du: cd thi cho rdng cdng sud't phat Laser khdng du hodc dlu thu khdng du nhay,v.v... ddn de'n nhihig giai phdp khic phuc khdng diing, lang phi, thdm chf khdng thdnh cdng. Cac ngi dung dugc trinh bay tren ddy khdng chi giup cho viec kilm tra, danh gia chdt lugng cac thie't bi quang hge, hy vgng rang nd cung giiip ich cho cong tac siia chira, ehl tao thie't bi quang hge d cac ca sd nghidn cuu va san xud't.