Tgp chi Khoa hoc - Cong nghe ThOy sdn

Tgp chi Khoa hoc - Cong nghe ThOy sdn

THONG BAO KHOA HOC

NGHIEN CUtJ CAI TIEN MAY DO CA DUNG M Q T TAN S6 SANG HAI TAN SO SONG SIEU AM NHAM NANG CAO

SAN Ll/^NG KHAI THAC THUY SAN

RESEARCH TO IMPROVE FISH FINDER FROM USING SINGLE FREQUENCY TO CHANGE DUAL-FREQUENCY TO INCREASE FISHING YIELDS

TrSn Tiin PhAc' Ngiiy nhan bai: 16/5/2013; Ngiy phan bien thong qua: 19/6/2013, Ngay duy^l dang: 10/9/2013

T6M TAT

Thoi gian tnt&c day nhimg mdy dd cd mot tdn so 50kHz du(rc dung rdt phd bien trong nghe cd Viet Nam Ngu trudng cua cdc tinh Nam Trung bd co nhieu cd Cam mom, cd Cam sdn Do kich thuac cd Cam mom, cd Cam sdn rdt nho nen mdy diing tdn so 50kHz khong phdt hien ro. De do cdc ddn cd ndy phdi dung mdy tdn so cao (200kHz). Bdo cdo ndy trinh bdy phuang phdp cdi tien mdy do cd FURUNO FCV668 (mpt tdn so 50kHz) sang hai tan sd 50/200kHz cho ngu ddn Qudng Ngdi, Phu Yen, Khdnh Hoa ldm nghe khai thdc cd Ccrm dat hieu qud cao han.

Tit khda. Mdy dd cd, hai tdn so, cd Cam ABSTRACT

Formerly, the fishjinders with frequency 50kHz are widely used in Vietnam fisheries Fishing grounds of the south central provinces has the Spined anchovy. The machines using 50kHz frequency are not clearly detected due to the small size of these kinds offish. To detect the small fish, one must use thefishfinders with higher frequency (200kHz). In this paper, we present method to improve the FURUNO FCV668fishfinder (a single frequency of 50kHz) into two frequencies 50/200kHzfor fishermen of Quang Ngai, Phu Yen, Khanh Hoa provinces, in order to achieve higher efficiency ofthe Spined anchovy exploitation.

Keywords' Fishfinder, two frequencies. Anchovy

I. DAT V A N O £ dieu ehinh hg s l khulch dgi (AUTO GAIN) va chtim Ngdy nay, mdy dd d bang phuang phdp sieu tia phdt ra rpng (tin s l sidu dm thap) de de tim thay dm Id thilt bj dign tu- hdng hdi khdng t h i thilu doi dan d dugc uu tien len hang d i u . Thye te cho thiy, vdi mdt s l nghi khai thdc ed biln m l i khi tau ra nhieu tdu dd dgt sdn luang cao han ngay tir chuyin khai. Khdng nhQ-ng chi d l dd ed md d khi hdnh biln dau tien nhd ed mdy dd cd. Sau vdi nam sir trinh di v l , mdy ed c h i dp ty dpng dieu ehinh cdc dyng may dd d . ngu trudng cdng dupc md rpng, tham sd thang do sdu. hg so khuech dgi tin higu dpi, nguon Igi d nhieu thay d l i , nhu d u phdt hien nhilu giiip thuyin trudng phdt hien rd ddy bien (dp sdu va logi ca tuy theo miia vu de tang sdn lugng dugc d c S\a hinh) d l nhdn d|nh ngu trudng vd phdng ngua thuyin trudng quan tdm.

mic cgn. Sdng sidu am ddi Igi tO' ddn d phy thupe vdo Thdi gian d i u triln khai mdy dd d d Vidt Nam, kich thude d c cd t h i trong ddn md trong dd bong nguIn Igi d n r i t phong phu md ngu dan Igi chua bdng d vai trd r i t quan tnpng. Bong bdng cd Id quen sir dyng, ngdn ngu hiln thj tren mgt mdy bang mgt ndi quan d a cdc iodi d , cd hinh dgng nhu mdt tilng Anh ndn hudng lya ehpn logi cd chtrc nang ty chile tti chua khdng khi giup d cd t h i dilu chmh dOng dilu chinh thang do (AUTO RANG), ty dgng dugc fi trcing vd khd nang noi cua minh, dieu ndy

' TS Trdn Tiln Phirc. Khoa Di#n - Di#n ti> - Tnr&ng Dgi hpe Nha Trang

TRUONG OAI HOC NHA TRANG • 33

Tgp chi Khoa hoc - Cong nghe Thiiy sdn So 3/2013

khiln d cd t h i la Itrng d mdt dp sdu nhit dinh md khong d n phdi bai [1]. Bong bdng cd cung cd tdc dyng giu thdng bang vi tgi tu t h i "chuin" cua d , trpng tdm khii lugng s§ ndm d phfa dudi trpng tdm cOa t h i tich do bong bdng cd ndm d mat lung cua ca t h i . Mdt chirc nang khac etia bong bdng d Id buing eong hudng nhdm tilp nhdn hay tgo ra dm thanh Sdng sieu dm eija mdy dd bj phdn xg mgnh nhat ttr bong t>dng ed vi tiJi khi tgo ndn sy chenh Igch rat Idn ve trd am so vdi phin thdn chO y l u la md mem (soft tissue) vd nud^ biln (hinh 1). 0^

phat hidn d d kieh thudc nhd khdng nhirng d n phdt xung sieu dm d d n g suit icm, dd nhgy maeh thu cao md cdn phai dung t i n s l phu hgp. Chinh vi vdy, d l tim dan d Cam Mom, ca Cam San ed nhilu d ngu trudng nude ta [2] d n su dyng mdy dd tan so sieu dm eao (logi 200kHz).

11. D 6 I TygrNG VA PHuaNG PHAP NGHI£N cCru

1. Doi tugng nghien cini: May do tim cac loai cd Com cd kich thirfrc nhd Phan xa song sieu am

t y mat da ciia ca

Hinh 1. Sdng siSu Sm phan la ttr c^ Cmn Tren t h i gidi. ed Cam tdp Uung nhilu d Dai Tdy Duang vd Thai Binh Duang. Ke tU' thgp nien 1980, nguIn Igi ed Cam da suy gidm vd thu hgp vung ngu tnj'dng Theo ban do phdn bo cd Cam (hinh 2) [3]

trong nhiJng nam g i n ddy, ngu tnrdng biln Miln Nam nude ta v i n duqc eoi Id trpng dilm.

Cd Cam cd nhilu chung logt, d moi dja phuang ed nhirng tdn gpi khde nhau nhu: ed Cam trang, ed Cam ru6i, cd Cam sdn. ed Cam than, ed Cam mIm, ed Cam trdng. Thilt bj didn ti> phdt hidn duge cdc dan cd phy thupc vdo mat dp, dp Idn ddn ea vd kich thude mli con ed trong ddn nen ed t h i chia cd Cam thdnh hai nhdm.

i|M|l i|ll |ll|ll.|l.lliliilJ 4 6 6 7 Hinh 3. Kich thirdt c6 Cmn va bong bong

Map for Stolephotusth (Spined anchovy) www.aquamaps org, version of Aug. 2 0 ^

Htnh 2. Ngir trujrag ci Cvm Nhdm cd kich thudc khai thdc Idn nliir cd Cam mdi, cd Cam thudng; Ten khoa hgc:

Stelephonjs commersonii (Lacepede, 1803); Tdn tieng Anh: Commerson's anchovy. [4, 5].

Nhdm cd kieh thudc khai thdc nhd han nhu cd Cam mom, cd Cam sdn; Tdn khoa hpe- Stolephoms tri (Bleaker, 1852); Tdn tilng Anh: Spined anchovy {4, 5] (hinh 3)

Cd Cam Id thye pham cd t h i dn song, phai kh6 hay c h i biln thdnh nhirng san phim d gia trj cao ve dinh dudng nhu nude mdm. Hign nay, nghi khai thdc cd Cam cua \fidt Nam tap trung chu ylu ir dc tinh miln Trung vd Nam Bp.

Khai thdc ed Cam da d tu' r i t Idu ddi vd Id nghi ddnh bat truyin thong d Viet Nam. Ngu eu Wiai thdc ed Cam chu y l u Id: Vdy mung, Pha xtic, Manh ddn, Mdnh mung Ca Cam cd t h i khai thdc quanh nim, nhung tdp tmng nhilu vdo vy ca nam tu thdng 3 din thdng g hdng ndm

Thye trang nghi khai \hic ci Cam d Vigt Nam van dang edn nhilu v i n d l d n dugc nghien ciru tif cdng nghg, quy md khai thdc. bdo qudn, c h i bi^n d i n fidu thy d n phim cung nhu bdo ve nguIn \gi-

34 • TRU{!)NG DAI HOC NHA TRANG

Tg£^chiKhoa ^QC - Cong nghe Thuy sdn

Vide chuyin giao edng ngh§ v l trang bj ddng lye, d n g nghd chilu sdng bdng LED d l ddn dy, vgt ligu ngu cy khai thdc ed Cam v i n dang d n duge tiep tuc. Trong dd, mdy dd tim dan cd Cam mdm, cd Cam sdn sao cho hidu qud Id npi dung nghidn cuu dugc trinh bdy trong bdi bdo ndy.

2. Phirong phap nghien ciKi

Tdc gid su- dyng hai phuang phdp chu yeu:

- Nghidn cuu ly thuylt v l mtre dd phdn xa sdng sieu dm khi ggp cd Cam trong nude.

- Nghien cyu thye nghigm d i tiln cdc may dd cd hign huu de phdt hien rd cdc logi cd Cam mom vd cd Cam san cd kieh thudc nhd, gid trj kinh t l cao. Logi ed Cam ndy cd nhieu d ngu tnrdng cde tinh Nam Trung b0.

III. K E T Q U A N G H I E N CCPU V A T H A O LUAN

1. Nghien cu-u mipc dg phdn xg sdng sidu am tie ca Com m I m vd ca Cam san

Dung sdng sidu dm d l do dO sdu vd tim cae mye tidu trong nude Id phuang an tdi uu nhit hign nay. T i c dd sdng am-sieu dm trong nude biln Id mpt hdm phuc tgp, phy thugc vdo dp lyc (do sau), nhigt dg (thay doi 1°C-4m/s). vd dg mgn (dd muli thay d l i cua 1%o-1m/s) Phuang trinh thye nghiem (1) d l tinh vdn t i c sdng dm-sidu dm treng nude biln.

ciT, S, z)^a^ + a^T+ a^P + aj^ + a^{S~ 35) + a^ + a / + a^TlS-SS) + a^Tz' (1) Trong do, T Id nhidt dp tinh bang thang Celsius, S Id dp mgn ttnh bdng phan nghin, z Id dp sdu tinh bang mdt [6].

Cde hang sl: a =1448.96; a =4.591; a =-5.304>^ 10--; a=2.374^1(r': a =1.340;

a=1.630^m'; a =1.675^10-': a =-1.025x10-^; a^=-7.139xia'K Chi so vgn t i e sdng dm - sieu dm trong nude biln thudng dQng d l tinh todn vd che tgo mdy dd cd vde khodng 1500 m/s Nhu vdy nlu mdy dd cd dting tan s l 50kHz thi budc sdng trong nude biln Id A.

'™° — - "--- ^ „ = i = ^ ^ = 0.0075™ = 7.5™», (2) /I ;= — = -t:^^^^ = 0,03m = 30mm;

/ 50000 / 200000

Sdng sieu dm se phdn xg khi ggp mdi trudng bat dong nhat trong nude d kich thude Idn han nira budc sdna.

^ A5o=/l5(,/2 = 0 . 0 3 / 2 - 0 . 0 1 5 m = 15mm (3) Nlu dung tan so 200kHz thi dp phdn gidi tang len gap b i n lan nhu k i t qud d bieu thire (4).

A2^=A^^/2 = 0.0075 / 2 = 0.a0375m = 3.75mm (4) Hg so phan xg sdng sidu dm trong nude khi gap mdi tnrdng khdng dong nhit (bpt khi, thjt ed, ddy bien) phy thupc vdo sy chenh Igch trd khdng dm Z vd dugc tinh theo bilu thtre (5).

* = ^ ^ (5)

Trong dd Z, Id trd khdng dm cua mdi trudng sdng tdi, Z^ Id trd khdng dm eiia mdi trudng gdy phdn xg, Theo nhQ-ng kit qud nghidn cdu ve trd khdng dm da duac cdng b l [7] doi vdi nude (water), md mem (soft tissue) (bdng 1) thi ti Ig sdng sidu dm phdn xg giua nude vdi thit d Id R„_^ cd gid trj khoang 4% Trong khi dd. ti Id sdng sidu dm phan xg giira thjt cd vdi khdng khi trong bong bdng cd Id R^^u, cd gid trj khodng 99.g5%

Bang 1. Hg so phdn xa sdng sieu am giira nipoc va ca MAIbvAng

Nude (vi/ater) Thjt d (soft tissue)

Khdng khi trong bong bdng d (air) Z(MegaRayls)

Z^=1.50 Z„=1.63 Z^ = 0.0004

H? so phan x? R

z„ + z. = 0.04153

Zn*2„ = 0.9995

TRLTONG OAI HOC NHA TRANG • 35

Tgp chi Khoa hgc - Cong nghe Thuy sdn So 3/2013

Hg so phdn xg R^Jc/n g i p 24 lan R^^n^'n bong bdng d ddng vai

trd rat quan trpng d mdy dd d bdng phuang phdp sidu dm Ngoai ra, sdng sidu am phdn xa tir ca frong nude cdn bj phdn tdn trong gdc khii Idn ndn ndng lugng thu nhdn dugc d diu dd Id r i t nhd, Neu t i n so sdng sidu dm thip. budc sdng ddi, khdng gay phan xa tren bong bdng eiia d c lodi cd nhd thi chi phdt hien dugc nhung dan ed logi ndy^khi tru' lugng r i t Idn vd mdt dd bai ddy ddc. Dilu kien nay r i t it xay ra doi vdi d Cam mom vd cd Cam sdn d ngu trudng Vigt Nam.

Trong thye t l , mdy dd cd FURUNO FCV668 tan s l sidu dm 50kHz chi phdt hidn dugc nhu'ng ddn cd Cam thudng eo do ddi than 60 d i n 70mm trd Idn. D l phdt hign cdc dan d Cam mIm, ed Cam san ed dO ddi thdn 30 d i n 40mm cin dung mdy dd ed tan so sieu dm dti cao, budc sdng ngin han kich thudc hieu dyng eua bong bdng ed (< 10mm) (hinh 3). Ddy Id dilu kign d n d l mdy dd phdt hien ddn d Cam mIm, cd Cam san, logi d d nhieu d ngu tnrdng cde tinh Miln Tmng nude ta. Logi d ndy d mdu trang trong. rit mem vd deo, dge bigt ngon. chQ yeu xult khiu sang Ddt Loan, Hdn QuIc, gid cao han g i p han 2 i l n d Cam Uiudng [8].

2. Nghidn ci>u lya chgn logi dau dd thu phdt hai t i n so phii hgp d l phat hi^n cd Comi m I m , cd Com san

Mdy dd d FURUNO FCV668 chi thi trdn mdn hinh mdu duge dung pho bien vd thdnh edng nhat tmng thdi ky diu nghien ctru trien khai ung dyng ir Vigt Nam. Trong thdi ky dau dng dyng mdy dd, ede nghe Vdy mung. Pha xiJc, Mdnh ddn, Mdnh mCing duge khuyen cdo dQng t i n s l 50kHz vl gdc phdt cOa chum tia r^ng hon, ngudi dung de tim thiy ddn ed han (hinh 4).

De mdy hogt dOng duge hai tan so trong dd cd tan s l cao ddp dng dd dugc ddn cd Cam mIm, cd Com sdn thi dudng ddc tinh dign khdng cd hai dilm trd khdng eye tiiu trQng vdi d n g hudng ciia mgeh dign tin thu phdt sidu dm.

Cdc hang ehi tgo d i u dd gim dp didn thudng chgn t i n s l 50kHz d n g hudng theo dudng kinh vd d t i n so 200kHz edng hudng theo kieh thude dp day eiia dTa gom Cd nhilu logi d i u dd thu phdt t i n so kep dupc bdn trdn thj tnrdng t h i gidi phu hgp ve tan so vd cdng suit nhu: 520-5PSC-A; 520-5MSC; 524ST-MSA;

520ST-PWA [9]. Do tdp qudn sir dyng vd each lap ddt eiJa ngu ddn Vigt Nam vd thye nghigm de didn khdng thi chi logi 520-5PSC-Avd 520-5MSC Id phii hgp han (hinh 5).

3. Nghien ciru cdi t i l n mgch d l thu phdt dugv ca hai t i n s6

Tu vide tim hilu sa do vd phdn tieh nguydn I;? lam vide cda mgch thu phdt xung sidu dm [9] ta thay dugc cdc linh kidn quylt d|nh tan so: phoi hgp thu phdt, d n g hudng ldi vdo mgeh thu vd d n g hudng bang gom ho CSB (Ceramic Resonator).

520.5MSC Hinh 5. Lofi dau dd

BA lung b^ lpc g6fn c^ng h irang CSBBSB h o ^ I09I ttra'ng duvng v i o chin

T v i S c u i U I I

Hinh 6. Nhihig linh kif n l i p bS sung trong khoi Ihu p h i t v i 19c egng birdrng

36 • TRUONG DAI HQC NHA TRANG

Tgp chi Khoa hQc - Cong nghe Thuy sdn So 3/2013

Cdng hudng g i m la mdt linh kign dien ttr d

tinh dp dien md sa d l tuang duang nhu mpt khung d n g hudng LC nhung d ttnh chpn Ipc toL dd on djnh eao dudi tde dpng eiia nhidt dp. dp I m vd nhilu dign tu trudng ngodi. D i u dd cua mdy dd ca cung cung vdt ligu dp dien ndn dung cdng hudng gom trong mach Ipc vd dao ddng doi t i n se d tinh dong bd vd cho k i t qud thu phdt tin hi^u I n djnh cao han. Trong trudng hgp eu t h i ctia mdy dd ca FURUNO FCV668 khi d i tien d l hogt ddng d tan s l 50/200kHz thi cd I h i lap bo sung cpng hudng g i m CSB655 hoacZTB655^

4. Nghien ciru doi chirang trinh vd ngp Igi EPROM

EPROM (Electrically Programmable Read Only Memory) la bg nhd md ngudi str dyng binh thudng chi cd t h i dpe chu khdng ghi ndi dung vdo dugc. Npi dung cda EPROM khdng bj m i t khi m i t nguon nudi, nd dugc gdn s i n trong mdy vd da dugc hang ngp san hg dieu hdnh [10].

Chuang trinh ghi trong EPROM tgo ede giao didn tren mdn hinh.

Vdi mdy FURUNO FCV668 dimg EPROM hp 27C010ddung lugng 1 MB chya chuang trinh tgo giao didn trdn mdn hinh gem cdc MODE: NORM;

^ -m

Hinh 7. X6a EPROM dl nap chinnig trinh M/Z; B/L; B/Z; GRAPH; DATA; MENU (hinh 8). Khi d i tiln d l may dd dugc d hai tan d n uu tien ba MODE dau- Dd binh thudng d tan so 200kHz, dd binh thudng d tan s l 50kHz vd dd cd hai tan so 50/200kHz. Trong chuang trinh mdi (tdc gia se trao doi d mot bai vilt khde ve tin hpe), khi dd hai t i n so, giao dign mdn hinh chia ddi theo chieu dung, k i t qud dd cua moi t i n so t h i hign tren mot nua, D l gidm chi phi, EPROM hp27C010 dugc xda chuang trinh cu bang ddn UV trong khodng 10 phut (hinh 7).

Sau khi kilm tra chat lugng xda dir lieu da hodn thdnh, nap lai chuang trinh mdi eho EPROM, Lap EPROM vao bang mgch vd kilm tra Igi cde IVIODE theo phdn bo mdi: NORM HF; NORM LF; DUAL;

M/Z HF; M/Z LF; DATA; MENU, Chtrc nang eua cde num nut dieu khiln edn lgi tren mdt mdy khdng thay doi (hinh 8).

Do t i n s 6 SOkHz ]/

Do tan sd 200kHz

Phong to k4t qua do 0' khoang do sau quan tam

Hinh 8. Ket q u i cai tien m i y FCV668 dung mgt tan so SOkHz sang hai tan so 50/200kHz IV. K^T LUAN VA K I 6 N NGH! "^^n, Khdnh Hda khai thdc bdng nghe Vay mung.

Chung tdi da su- dyng tren nam tram bd linh kidn d l d i t i l n mdy dd mdt t i n s l SOkHz thanh hai t i n s l 50 vd 200kHz cho ngu ddn Quang Ngai, Phu

Pha xue, Manh ddn, Mdnh miing nham phdt hign tot cae ddn ca Cam mom. d Cam sdn gdp phin ldm tang ndng suit vd hidu qua kinh t l . Chi phi d l tiln

' Cdc linh ki§n n^y khdng pho thflng tren thj truong di§n tir dan dung it Vigt Nam nen nlu ai quan tam den vi^c cai tien may dd cd thdnh hai t^n s l md g^p kho khdn xin lien hg vdi tac gia bai viet

TRUONG DAI HOC NHA TRANG • 37

Tgp chi Khoa hoc - Cong nghe Thdy sdn So 3/2013

vua re ban so vdi vide mua them mdt mdy dd nua

hogt ddng d tan s l 200kHz vua thudn tidn trong vige triln khai sir dyng trdn tdu.

So lugng mdy dd ed chi dting mpt tan so 50kHz trong nghi cd d nude Id rat Idn. C i n xdc djnh rd ngu trudng cua cde tinh tu Ninh Thudn din Kien Giang vd mua vy khai thdc d Cam mIm, ed Com sdn hodc cdc lodi cd khde khi da trudng thanh d kieh thudc nhd d l khuyin cdo bd con ngu dan d i tiln mdy dang dung hogc khi mua may mdi d n chpn loai hai t i n s l 50/200kHz.

\^dc cdi tiln mdy dd cd tu mpt tan sd sang dQng

hai tan s l phdi tiln hdnh dOng bd: dau dd, mgch dign tir vd h§ dilu hdnh trong ROM (phan mem) Dong thdi. hudng dan cho ngudi sir dyng cdch vdn hdnh num MODE trdn mat mdy sau khi cai tien.

Hidn tgi trdn thj tnrdng Vidt Nam cd mdy FCV 627 bdo dugc kfch thudc tuong d l i cua cd ttong ddn nhung phdi dting dting logi diu dd cd ho tn?

chtrc ndng ndy vd ehi bdo dugc d nhung ddn cd a$

sdu trong khodng 2m d i n 100m. d$ ddi than cd phdi tir 10cm trd ldn. Tuy vdy, cdn phdi cdn cu vde thye t l khai thdc thtiy san d l dgt gid trj higu chinh tmng MENU mdi cd kit qua phu hgp [11].

TAI LIEU THAM KHAO Tieng Vift

http://tongcucthuysangovvn/d-khai-thac-bao-ve/a-ktts/ngu-dan-tinh-binh-lllinh-va-phu-yen-trung-lllam-ca-com http://wwwthanhnien.com.vn/pages/20130315/ngu-(ian-quang-ngai-boi-thu-ca-com-mom-15-3-20l3.aspx

Tieng Anh

http 7/science howstuffwoiks.com/zool ogy/niarine-life/question629.htm www.aquamaps org

http //www.fishbase.org http://www.seafood£rom viemam .com. vn.

http://resource. npi co. uk/acoustics/techguides/soundseawale r/

htq>://www.ch, qub.ac uk/phy sics/medical/usfoider/usprint.htm I

9 Funino electric co .ltd. Color \^deo Sounder FCV-667/668 Installation Manual, 2001 10. http://www.jmargolin.coni/patenls/eprom.htm

11. Funmo electric co.,ltd. Fish finder FCV 627,2011

38 - TRUONG OAI HOC NHA TRANG