T;p Chl GTVT 3/2012
IE
Dir DOAN TirOlNG QUAN CUA TAU MUC TIEU VOfl TAU CHU TRlTOlC VA SAU KHI HANH DONG TRANH VA
Tdm tit: Dtfdoin dUtfc tUdng quan glC^ tiu muc tiiu vdl tiu chu Ii cd s& di aua ra dc quyit ainh chlnh xic nhim trinh mit nguy cd dim va glOa hai tiu. Trong bit bio niy, cic cong thtfc ii tinh toin vi tri tUdng quan glQa hai tiu trudc vi sau khi hinh ding trinh va dtftfc xiy dtfng. NhQng dng thtfc dtf doin niy dtfpc Ung aung trong chi t^o thlit bj hi trd f^dng trinh dim va tiu thuyin trin biin.
Abstract: Estimation of the relative motion befween target ship and own ship is a base to make a correct decision for preventing collision between them. In this paper, the formulae, which are used for calculating relative motion ttetween 2 ships before and after action of avoiding collision, are made. These formulae are applied In making an aid for preventing collision at sea.
I.GIdl thldu
Trong didu khlln t i u , ngoii eie vdn dd phdc tgp vd khi ning chuyin dOng cda con t i u , didu klOn cda mdi trudng nPl nd dl qua thi cdn mOt ydu td quan trpng gdp phdn dim bio an toin hing hii cda con t i u dd, diy chfnh I i y l u td con ngudi. Da phin cic tal ngn dim va hing h i l dupc phin quydt la do eon ngudi g i y ra do chd quan, phin doin sal lim, hinh dOng sal luit... Bi gdp phin lim hgn chd cic tal ngn dim va glda t i u thuydn trin biln thi c i n thidt cd cic thidt bj phg trp gli^p con ngUdi dg doin tinh hudng tdt hPn tU dd dUa ra cic hinh dOng phd hpp. Vdl mgc tiiu dd, bii bio niy gidi thidu vlOc xiy dgng eae cdng thdc tfnh toin v i Ung dyng cCia chOng trong dg doin tUPng quan glda 2 t i u nhim trinh nguy cP dim va.
2. CO sd dU d o i n cac chuydn ddng tUOng quan glUa hai t i u
Dd dg doin tuong quan chuyen dpng gida cic t i u trudc v i sau khi hinh dpng trinh dim va. cac thdng sd vd chuydn dOng tUPng ddi glda tau chu v i t i u mgc tidu (V^. Cg. V E I . C E I ) dupc xic djnh. Khi eic t i u chuydn dOng, tUdng quan vd vj trf glda chung cd t h i cho ta dinh g l i khi ning cd xiy ra nguy cP dim va hay khdng. Khi bld't thdng tin vd chuydn ddng cua 1 tiu, c i n cU v i o tUPng quan glda t i u do vdl tau mgc tiiu cua nd chung ta cd thd xie djnh dupc cac thdng sd chuydn dOng cOa tau mgc tiiu d l cd cic bidn phip trinh va phd hpp. TU trude d i n nay, cac cdng vlOc niy dupe I i dUa trdn co sS dd giii trinh va tUPng ddl. Theo dd, chuydn dOng tudng ddi gida 2 t i u m i ngudi dldu khiln phuong tidn quan s i t dUOc se I i tdng hpp cda 2 chuydn dOng: Chuydn ddng cda t i u chu v i chuydn ddng cua t i u myc tidu (xem hinh 1).
Chuydn dOng cua t i u mye tiiu dupe xic djnh bing phUPng phip dd giii. Cin cU trin cO sd cda phuong phip dd g i i l , que phin tfch c i c tinh hudng toong
TS. PHAM VAN THUAN Trudng D9I hgc Hing hii quan gida cic t i u , cic h i cdng thdc d l tfnh toan eie chuydn dOng tuong quan gida hai t i u trUde va sau khi hanh ddng trinh va dgpc xiy dpng.
Hinh 1: Chuyin dgng tuong dii glda 2 tdu 3. Cdng thUc tfnh t o i n c i c thdng sd chuydn dpng tUdng quan gida hai t i u
Chuydn ddng tuong ddl ciia mgc tidu so vdl t i u chd gdm c i c thdng tin ve hudng v i tde dd djch chuyen: Vg v i Cg dugc md t i nhu d hinh 1. Ngoai ra, cic thdng tin d l djnh vj vj trf tuong ddi cua t i u mgc tieu cung cdn dUge xic djnh nhim cd thd bidu didn chuydn ddng cda mgc tiiu trin man i n h radar khi l i p trinh.
3.1. Niu phUdng vi quan sit khing thay doi
- Ndu khoing each quan s i t khdng thay d l i D-j = D2 thi inh eija mye tidu v§n ddng nguydn vl trf:
PTd = PT2ViOTd = Dd = D2.
- Ndu khoing each quan sit glim din (Dg < D-|) A .
Hinh 2: Tinh tdn dl chuyin ciia inh Mil phtfdng vi khing ail, khoing cich glim din
Theo hinh 2 ta thdy, khi phuong vj khdng d l i gida 2 lan quan sit:
Gpi t(j la thdi dilm bit kl ma i n h di chuyin trdn
min hinh radar sau thdi dilm quan s i t lan culi.
Atd = ' d - ' 2
- N l u thdi dilm td 6 tnidc hoic tai c i n diem (td<t2 + TcPA).
Ta cd: BTj = VE- 4 t j
Khcing c i c cua mgc tieu tai thdi dilm t j la:
0T(j = D2-BTtj
Phuong vi inh mgc Blu t?l thdi dilm t^ Ii: PT(j = PT2 - Nlu t i u mgc tiiu da dl qua oin dilm
(td>t2 + TcpA)
Khi mgc tiiu di qua c$n dilm, V^ d l i dau tu dUdng sang i m hay Vg = -1 .VE-
Khoing cich cda mgc liiu tai thdi dilm td I i : 0Td=IVEl.(td-t2-TcPA)
PhUdng vj inh mgc tiiu tai thdi diem t j la:
PTd = PT2 + 180° nlu (PT2 + 180°) < 360» n l u khio PTd = PT2-180°.
- Nlu khoing cich ting din (D2 > D^) Mgc tiiu d i di qua c^n dilm.
BTd = IVEl.Atd
' C E
HInfi 3: Tinh toin dl chuyin cua inh khi phuong vl khing ddl, khoing cich Ung Un
Khding cic ci^a mgc tiiu tai thdi dilm t^ I i : OT(j = D2 + BTd
PhUdng vi inh mgc tiiu tai thdi dilm t j i i : PT<j = PT2.
3.2, Niu phuong vj glOa cic Un quan sit thay ail(PT^*PT^
GQI td i i thdi dilm bit kl m i inh di chuyin trin min hinh radar sau thdi dilm quan s i t lln culi
t2.4td=td-t2. BTd^Vg.Atd Khoing cich cua mgc tiiu tal thdi diem td I i OTd= m+ B-I^+ 2X)2 JBTj.cos(^Bl)
BCTr|i=arcos
PhUdng vj ciJa mgc tiiu tai thdi dilm td i i PTd.
Ta thiy ring, biln thiln cua phUdng vj Td phg thg|c v i o biln thiln cOa phUdng vj cic lln quan sit.
•Nlu-180»£(PT2-PTi)<()«
Hinh 4: Tinh toin khing chuyin ding tuang dgl
khi phuong vi thay dSl _ _ a thlPTd=PT!-B07i nlu khic thi PTd =PT! + B i ^ B
- N l u P T « 2 360»thlllyPTa = PTa-360»; : * -NluPTa<0»thlilyPTd = PTd + 360°; • "
- Nlu khic, giO nguyin g i i trj.
Til thdng s i PT^ v i OT;, ta xic djnh dUdc tga ^ cOa mgc tiiu tai thdi dilm bit Wj/. Khi t i u chO thfiyj dlSl hudng di hay t i c d$ hoic c i hai cung Idc d l hinh d|ng trinh dim va tai thdi dilm T,,, khi dd tic dO v4 hudng di mdi cOa t i u chO se I i VQI v i CQI tUOng dng vai na I i hudng di v i t i c dd di chuyin tUdng dli cCia mgc tiiu i i V E I v i C E I .
Nhu viy, tai dilm TM nhu hinh 1, t i u chii hinti ddng trinh va vdi t i u mgc tiiu. Bilm Tm niy cd thJ dUdc coi tUdng dng vdi dilm quan s i t lln culi 8 nl)U trong cic clng thdc da nSu d trln. Ti3 sau T^, mtl|
tiiu se di chuyin vdi tudng d l i I i V E I v i V E I . Th^, lln luat cio y l u t l tuong dng k l trin ta cd thi tlnl toin dUdc phuong vj v i khoing cich tuong quan giOa t i u mgc tiiu v i tau chO tai thdi dilm bit kjr 8 ^ khi hanh ddng trinh va.
4. K i t lu|n
Vdi h i cdng thiJo dg doin tUOng quan giOa tiu chu v i t i u mgc tiiu da xiy dgng d trln ta cd thi ip dgng d l tinh toin tg d^ng tUdng quan giOa cic tiu, trin cd sd dd cd t h i tinh toin cic y l u t l khic phgc vg cho viic du doin chuyin ddng cCia con tiu cQvS nhu dua ra c i c phudng i n trinh va phCi hdp kit quft niy da dit mdt nln mong ban d l u cho vi$c phit triln thilt bi tg d|ng d l giii trinh va radar cho t i u thuyin tai Viit Nam phgc vg phit triln cic linh vgc phg M cho nginh Cdng nghiep ddng t i u . B i y cung i i tnpl budc d l t i l n tdl l i m chCi cio cdng nghi hl#n d i phgc vg bio d i m an toin hing h i i Q
Tai l i | u tham k h i o
[1]. Nguyin Viit Thinh, •Diiu ding tiu; 2010.:
[2]. Standard for ARPA nguin: httpJAmiw.tc.gci ca/eng/marinesafaly/tp-tp3ee8-9standard-950.hm
