Tuyen tap bao cao khoa hpc Hgi nghi Khoa hgc ky thuat Do luflng toan qudc lan thfl IV Hd Ndi, 11 - 2005
,BAI TOAN DO LUdNG CAC THONG SO THUAT PHONG NGOAI CUA DAN TICH CliC-PHAN LUC TREN CO S d LJfNG DUNG KY THUAT
RADAR
Ddo Hoa Viet
Khoa Ky thudt diiu khien - Hgc vien Ky thudt Qudn sif BUi Tudn Anh
Vien Vu Khi Trung tdm Khoa hgc ky thudt- Cong nghe Qiidii sif, Bd Qud'c phong
Tdm tdt:
Bdi bdo nghien cdu cdc vd'ii di ca bdn cua bdi todn do lifdng cdc thdng sd thudt phdng ngodi ciia dgn tich cUc - phdn life tren ca sd ifng diing ky Oiiidt radar doppler ; bao gom: nguyen ly do, md hinh finh todn, cd'u tnic ciia he do ..vv.
Trong hdi hao ndy, cdc tdc gid cung di xud't mgt so hifdng nghien cifu phdt trien nhdm muc dich ndng cao tinh chu dgng sdng tgo trong cdng tdt do Itfdng vu khi, tiet kiem ngdn sdch Qud'c phong.
Abstract:
This article researchs basic points of measurement for exterior ballistic parametters of active-rocket ammunadons based on using Radar doppler technii; including of Measuring principle. Calculating model. Structure of system etc....
In this article. Writeis also point out some ways on developing research in order to improve active of weapon measurement tasks, saving spendings on the Army.
I. DAT VAN DE
Ngay nay cung vdi su phdt trien manh me cua khoa hgc ky thudt ndi chung, dac biet la trong ITnh vuc dien tfl va cdng nghfi thdng tin, ky Ihudt do ludng cac thdng sd thuat phdng dd phuc vu cdng tdc nghien ciiu, thifi't kfi', chfi' tao vQ khf da dat dugc nhflng tifi'n bd vugt bdc. Ben canh cac he thdng thiet bi flng dung nguyfin ly dp difin de do dudng cong ap sud't trong ndng phao va cac bdy quang dd do td'c do ddu ndng cua vien dan (hai thdng sd co ban ciia thuSt phdng trong) va cac thifi't bj quang difin hifin dai dCing dd khao sdt qua tiinb tac ddng sau ciing cua khf thudc Ifin vifin dan (thudt phdng trung gian), qud trinh tac ddng cua vifin dan khi cham muc tieu (thuat phdng sau cimg); viec flng dung ky thudt radar dd khao sal cac thdng so chuyen dgng cua vien dan trfin dudng bay (thuat phdng ngoai) la giai phap cd hifiu qua dang dugc sfl dung rdng rai b cdc nudc phat trien trfin the' gidi.
II. CAC GIAI PHAP KY THUAT KHI DO CAC THONG SO THUAT PHONG NGOAI BANG HIEU UNG RADAR DOPPLER
2.1. Bai loan xac dinh van tdc huflng tam cua dan.
Khi sdng radar phan xa vd tfl mdt vdt bay ( tfin lua, may bay, dan cac loai ...) Ihi tdn sd cua nd se bi thay ddi di mdt lugng ggi la tan sd dich chuyen doppler. Tdn sd' nay phu thugc vao vdn td'c cua vdt bay vd tdn so phat cua dai radar. Sau day ta thd'ng nhd't hifiu ten ggi vdt bay chi'nh la cdc loai dan.
Ndu la ggi / Q la tan sd phat cua radar, V^ la vdn td'c hudng tam cua vdt bay so vdi dai radar thi tdn sd' doppler dugc xac djnh bdi cdng thflc:
Trong dd: C la vdn tdc anh sang (C = 3.10^ m/s).
Nhu vdy ne'u ta xac dinh dugc tan s6 doppler tuong flng vdi vdt bay thi co thd tinh toan dugc vdn td'c hudng tdm cua nd:
' " 2 . / „ ^'
Vific linh loan tdn sd doppler dua tren thuat loan bifi'n ddi Fourier nhanh (FFT).
Phuong phap nay ddi hoi trudc tifin ta phai tieh hanh chuydn ddi tin hifiu radar lifin tuc thanh tin hifiu sd (tflc la thflc hifin phep bifi'n ddi A/D). Tuy nhien dd dam bao cho phep bien ddi A/D khong lam mdi't di thdng tin vfi tin hieu muc tifiu thi tdn sd' ld'y mau phai thoa man djnh ly Nyquist, tflc la: / ; „ > 2/^^^
Trongdd: f/^ - Tdn sd l^y mdu (Hz).
/max " ^ ^ ^^ ^^^ 'l'?^ ^^^ *^?^-
Vific lua chgn tdn sd Id^y mdu / ) ^ phu thudc vao vific thifi't ddt tham sd vdn tdc td'i da (Vfnax) "^^ ^^" ^° ^^^ ^^^ dugc. Dua trfin tham sd nay, kfi't hgp vdi tan sd/o cua radar, hfi thdng se ti^n hanh tinh toan tdn sd' Id'y mdu ldi uu.
Dd Ihuc hifin phep bifi'n ddi FFT ta cdn phai chgn mgt sd lugng cdc mdu N (cdc mdu nay dugc ggi la cac didm FFT). Tuy thudc vao su thay ddi vdn tdc cua vifin dan (tuong flng vdi su thay ddi tdn s d / ^ ) sd lugng cac didm FFT cd thd tbay ddi tfl 32 dfi'n 4096 mdu.
O ddy chung tdi chgn N = 1024 mdu tflong flng vdi 1Kb bd nhd.
Chu ky cua mdt phep do van td'c dugc xdc djnh la khoang thdi gian can thi^t dd thuc hien vific ld'y mdu cac didm FFT da chgn: Tj^ = N.—
Jim
Vific tang sd didm FFT (N) se lam giam lap am trong may thu radar bdi vi thdi gian do cang ldn thi ty sd tin/tap dat dugc tai dau vao may thu cang tang va dfi chi'nh xac cua phep do cang ldn. Tuy nhien trong mgt sd trudng hgp ta phai tfnh loan sao cho viec chgn sd didm FFT khdng lam anh hudng dfi'n thdi gian xfl Iy tin hifiu cua hfi thdng ma phep do van dat dugc dd chfnh xac cdn thifi't.
Mdt trong nhiitig uu didm ndi bdt cua phuong phap xac dinh tdn s6 doppler dua tren ky thudt FFT Id nd co kha ndng do dugc chi'nh xac vdn tdc cua muc tifiu. Thdm chi neu trong vung quan sat cua Radar cung mdt luc xud't hifin nhidu muc tieu (trong trucmg hgp bdn - do thfl nghiem cac loai dan phdn manh, dan chum v.v...) thi nd vdn cd thd xac dinh chi'nh xac v$n tdc cua tflng muc tifiu dd (cac manh, ddu dan con). Day la mdt budc tien quan trgng trong ITnh vuc do ludng cac thfing sd thudt phong.
2.2. Bai toan xac dinh van too thuc va cac thong sd quy dao cua dan
Vdn td'c thuc cua cac loai dan, ten Ifla v.v... la mdt trong nhung thdng sd quan trong trong do ludng cdc thdng sd thudt phdng vu khi.
Di hidu ro phuong phap xac dinh cac thdng sd quy dao cua cac loai dan (sau ddy dugc ggi la muc tifiu) ta hay xem xet md hinh quy dao sau;
763
Trong md hinh trfin cac thdng sd quy dao dugc djnh nghia nhu sau:
- Gdc nghifing ttj: Gdc gifla tifi'p luyen cua quy dao va ducmg nam ngang.
- Gdc ngdm ao: Gdc gifla dudng ngdm va dudng ndm ngang.
- Gdc hudng muc tieu a,: Gdc gifla true dd'i xflng cua vifin dan vd ducmg ngdm.
Tfl cac vec to vdn td'c cua vifin dan ta c6 md'i lien hfi vd mdt djnh Iugng giua vdn tdc thuc cua vifin dan nhu sau:
Hlnh I. Cac thfing sd quy dao cua dan
C
''2.f,
L
(3)Cosa^ 2.fi Cosa^
Bang each sfl dung ky thuat FFT nhu da dd cap 6 trfin ta cd thd xac dinh dugc tdn sd doppler f^ (tflc la xdc dinh dflgc vdn td'c hudng tam V^) tai ti^g thdi didm trong qua trinh chuydn ddng cua vifin dan trfin quy dao .
Nhu vdy bai toan xac djnh vdn tdc thuc cfla vifin dan trfin dfl^g bay quy vd xac dinh gdc hudng muc tifiu a^ tai tflng thdi didm trfin quy dao cua no hay noi mgt each khac la xdc dinh a^ (f) .
Gdc hudng muc tifiu CC^ 1& mdt tham sd quan trgng quydt dinh be mat phan xa bifiu dting cua vien dan (RSC). Vdi mfit hfi thd'ng radar xac dinh ndu vifin dan bay cd true ddi xflng trung vdi true bup song quet cua dai radar thi khi do radar se chieu xa no vdi mdt gdc hudng Ofi = 0 va bd mat phan xa hieu dung cua vifin dan dat gia tri cue dai.
TT' ,4 ( 4 )
Trong dd : X- Budc song cfla dai radar.
d - Ducmg kinh cua vifin dan.
Vi goc hudng muc tifiu a, hoan toan phu thudc vko quy dao bay cua vifin dan trong khdng gian nen viec xac dinh a, dugc tien hanh thdng qua vific tinh toan quy dao. Thuc chd't cua qua trinh nay chinh la tidn hanh giai hfi phuong trinh vi phdn mO ta chuydn ddng
ciia dan trong khdng gian. Trong qua trinh tfnh toan quy dao dan, se thuc hifin viec tinh loan cac he sd cua cdc luc tac dgng len dan dua trfin cac gia trj vdn tdc hudng ldm V^ do dugc bdng anten radar doppler .
Vific tfnh loan quy dao dugc thuc hifin bdi bd phdn tich radar doppler (phan cflng) ke't hgp vdi phdn mem chuyen dung vdi cac tham sd ddu vao la; cac tham sd vfi qua dan (dudng kfnh dan d, khfi'i Iugng dan m); cdc tham sd vd dd'i tugng thfl nghiem (chidu dai ndng sung, vi tri cua didm dat anten radar so vdi diem dat siing, gdc ngdm cua sung); cac chfi'do bdn (bdn phdt mfit hay bdn loat); cdc tham sd vd mdi trudng (van toe gid, mdt dd khdng khi, nhiet dd, dd dm).
Bd phdn tich radar doppler sfl dung md hinh quy dao va cac phep tinh dfi xac djnh cac thdng sd quy dao,van td'c va he so luc can. Tuy nhien, tuy thudc vao loai dan thfl nghifim ma ta sfl dung mdt trong hai md hinh sau day:
Md hlnh quy dao chat die'm (Point Mass Trajectory Model).
Mfi hinh nay dugc sfl dung cho cac loai dan cd nho, dan cdi, dan chdng tang, dan rocket cd tam bdn ngdn ma d dd cac luc tdc ddng chu yfi'u lfin chiing khi chuyfi'n dgng trong khdng khf chi bao gdm trgng luc va luc can khdng khf.
Md binb quy dao chat didm bifi'n ddi (Modified Poin Mass Trajectory Model).
Md hinh nay dugc sfl dung cho cac loai dan quay cd dn djnh spin, dac bifit la cac loai dan phao lam xa. Md hlnh quy dao cua cdc loai dan quay cd dn djnh Spin dflgc xac djnh theo tifiu chudn NATOSTANAQ No.4355 (lheo[6I). Chuyfin ddng quay Spin cua dan tao nfin do su khdng dd'i xflng cua dan dd'i vdi true doc vd hinh thanh gdc chuong ddng a la gdc gifla vec to vdn td'c V va true dgc cua dan.
Viec giai hfi phuong trinh chuydn ddng ciia dan theo phuong phap tfch phdn so Runge-Kutta dugc thuc hifin bdng phdn mdm chuyfin dung "nhung" trong bfi phdn ti'ch radar doppler. Sau khi giai ta se nhdn dugc cac thdng sd thuat phdng ngoai cua dan nhu:
Luc can, luc dat, luc Magnus, trong luc, luc Criolit v.v... va cdc he sd luc can tuong flng.
Tdm lai: qua trinh phdn lich quy dao dan de xdc dinh cac thdng so thudt phdng ngoai trong mdt he thd'ng Radar Doppler do ludng IhuSt phdng dugc thuc hifin theo trinh tu sau:
1. Trudc hfi't bdng vific sfl ly sd tin hieu radar phan xa vd tfl muc tifiu bay trfin co sd cua thudt todn bie'n ddi Fourier nhanh FFT he thdng se lien hanh phan lich cdc tin hieu doppler nhdn dugc dd xac djnh cac thanh phdn van tdc hudng tdm cua muc tieu va ddng thdi xdc djnh su thay ddi cua ty so tin/tap tai ddu ra cua mdy thu radar trong sud't qua tnnh chuyen ddng trfin quy dao cua dan.
Gid trj vSn td'c hudng tam tai diem ddu quy dao se dugc sfl dung dd xac djnh vdn tdc ddu ndng ctia vien dan, cdc gid tri vdn tdc hudng tdm tai cac diem khac trfin quy dao se dugc sfl dung dd xac djnh cdc didm van tdc thuc tuong flng tren quy dao cua vifin dan.
2. Trfin co sd cac tham sd ve ddi tugng do, gia trj van td'c hudng tam, va gde ngdm muc tifiu phdn mem chuyfin dung se thuc hifin vific giai hfi phuong trinh vi phdn md ta chuyfin ddng tdng quat ciia dan trong khdng gian dd xac djnh cac luc tac dgng Ifin qua dan va thuc hien tfnh loan cac thdng sd dudng dan.
III. CAU TRUC CUA MOT HE THONG RADAR DOPPLER DO L U 6 N G THUAT PHONG
Trfin day ta da nghien cflu nguyen tdc do cac thdng sd thuat phdng ngoai cua dan tren CO sd flng dling nguyfin Iy radar doppler. Tfl cac nghien ciiu nay ta thd'y cau true cua mgt hfi thd'ng radar doppler do ludng thuat phdng bao gdm cdc thanh phan sau (hinh 2).
Chfle nang cua cac thie't bi trong hfi thd'ng;
- An ten radar doppler: Thuc hifin vific thu phat tin bifiu va thuc hifin li'nh loan tdn sd doppler.
- Thie't hi Triger: Thuc hien ki'ch boat va ddng bd hfi thd'ng.
- Bd phdn tich Radar doppler: Thiic hifin vific sfl ly sd tin hifiu doppler tuong tu tfl an ten chuydn sang va thuc hifin cac phep bifi'n ddi, giai hfi phuong trinh vi phdn md ta chuydn ddng cua dan trong khong gian dd xac dinh cdc thong so' thudt phdng ngoai cdn thifi't nhu:
V(t),V(d), A(t), A(d), quy dao XY, C(m), C(d) v.v...
- Thie't hi dieu khien chutmg trinh do (Instrument Controler): TTiuc hifin vific didu khidn tfl xa qua trinh do va ket xuat dfl lifiu trfin may PC thdng qua phdn mdm chuyfin dung REMDOPP. Phdn mdm nay cho phep ta thiet dat cac tham sd do va didu khidn hfi thd'ng thuc hifin cac thudt todn khfl nhifiu, thuat toan ndi, ngoai suy va giai hfi phuong flinh vi phan md ta chuydn ddng cua dan.
Hlnh 2. Cau true cua mdt he thdng Radar doppler do ludng thuat phong
IV. KET LUAN
Nhu vay vific xac dinh cac thdng sd dudng dan (thdng sd thuat phdng ngodi) bdng phdn mdm chuyfin dung kem theo cac giai phap ky thudt sfl Iy sd tin hifiu radar doppler !a mdt budc tifi^n quan trgng trong ky thudt do ludng cac thdng sd thudt phdng vu khi.
Trfin the' gidi mdi hang chd tao thiet bi do ludng thuat phdng ddu cd cac san phdm phdm mdm do rifing bifit dfldi dang Compac va dflgc bao vfi ban quydn r^t nghifim ngdt.
Vdi muc dich ndng cao tinh chu dgng sang tao trong cdng tac do ludng vu khf, tidt kifim ngan sach Qudc phdng; mdt vd'n dd bfle thidt dat ra cho chung ta la phai tu nghifin cflu xdy dung va phat tridn cac phdn mdm do ludng thuat phdng sao cho phii hgp vdi didu kifin cu thd cua cdng tac nghifin cthi, thidt kfi', chd tao vu khi trong Qudn ddi ta.
Tdi lieu tham khdo:
{!]. Nguyin Xidn Cdu (2003). Sif ly tin hieu radar. Bdi gidng chifang trinh cao hoc, Hgc vien KTQS. Hd Ndi.
[2}. Nguyin Tdng Cifdng (2003). Cdu triu vd lap trinh he do diiu khien. Hgc vien KTQS, Hd ndi.
[3]. Nguyin Dinh Sgi (1996), Thudt phdng ngodi. Hgc vien KTQS, Hd ndi.
[4]. Weibel Scientific A/S (2000). W-680/W700 Velocity Analyzer Refei ence Manual.
Grusbakken [-3 Copenhagen Denmark.
[5]. Terma Elektronik A/S (2001), Ballistic Doppler Radar Systems.Hovmarken Lystrup Denmark.
[6]. Terma Elektronik AIS (2002). Tracking Radar Systems, Hovmarken 4 Lystrup Denmark.
[7]. Terma Elektronik A/S (2002). Doppler Radar Perforuhmce. Hovmarken 4 Lystrup Denmark.
