Nghiên cứu ứng dụng hệ điều khiển bằng PLC cho cần trục tháp xây dựng

NGHIEN cai ONG DUNG H$ OI^U KHI^N B A N G PLC CHO CAN TRUC THAP X A Y DUNG TS Truong Qudc Thanh Khoa Ca XSy dt/ng Trudng Dai hgc Xay dung Tdm tat: Bp diSu khiin lap trinh ggi tst la PLC cd thi dieu khiin linh boat dirge cac trang thai, ddi tugng hay mdt qua trinh cdng nghe thdng qua cac thuat toan dieu khiin nhd mdt ngdn ngO nhat djnh Bai bao gidi thieu ndi dung nghien cifu ifng dung he dieu khiin PLC he thdng dieu khiin can true thap Viec Cfng dung he diiu khiin PLC se la ca sd budc diu cho vide nang cao ehat lugng thiet ki, ehi tao mdi, nang cap eae ein true hien dang sCr dung d nude ta eOng nhu Ung dung he dieu khiin cho cae loai may xSy dung khae Summary: Programmable logic controller (PLC) can be used to control many states, objects or technological process flexibly by using control algorithms in a certain language tool The paper presents content and researches using PLC in tower crane control system Using PLC in not only the first step for improving the quality of design, manufacture but also for upgrading tower cranes used in Vietnam PLC ean also be used for the other construction machines MO DAU Trong ITnh vUc dieu khiin, phan biet hai phupng phap; phuong phap dieu khien ndi cdng vd phuong phap dieu khien lap trinh dupc Bd dieu khien lap trinh dupc (Programble Logic Controller) gpi t i t Id PLC ed the dieu khien linh hogt dupc cac trang thai, ddi tupng hay qua trinh cdng nghe thdng qua cae thuat toan diiu khien nho mdt ngon ngu nha't djnh He thdng diiu khien tren May xay dung ndi chung va tren ein tryc ndi rieng dong mpt vai tro quan trpng vide dam bao cho may lam vide mpt each em thuan, an toan, nang suit va tin eay Cho tdi nay, cae thiit ke nudc ve he dieu khien cin tryc van chu yeu theo phuong phap diiu khiin ndi cimg va ehua nim bat kip ky thuat tien tiin tren the gidi, dd phuong phap diiu khiin lap trinh se la ehu yeu Nghien cdu img dung ky thuat mdi dua tren he diiu khiin bing PLC hd thd'ng dieu khiin ein true nham ndng cao chat lUpng may mde thiet bi duoc c h i tao trona nude la mdt vide ldm ein thiet GIAI QUYET VAN DE D i cd t h i xSy dung phin mem diiu khien can true dupe cai dat tren PLC, cac tae gia da dl sdu nghien cUu mdt each diy dd ve cdng nghe hoat ddng va dieu khien cin true, cac yeu eiu ve dam bao an toan eho ein true qua trinh lam viec cung nhu eae vin d i lien quan den ky thuat didu khien thudc ITnh vUc co dien td Kit qua nghien cdu dupc img dyng eho mpt ddi tupng TAP CHi KHOA HOC CONG NGHe XAY DUNG SO 01-9/2007 47 cu the la Can true thap xay dung VICOX - CTM80 Tdng edng ty co Xay dUng c h i tao thd nghiem lan d i u tien d Viet Nam NGHIEN Ctru VE DAC DIEM CAU TAG, CONG NGHE HOAT OONG VA CAC YEU CAU VE AN TOAN CUA CAN TRUC THAP Viee nghien ciru ve qua trinh lam vide cda cac co ca'u cdng tac tren c i n true thap la co sd eho viec lua chpn thiet bj va bd tri sP dieu khien mpt each phu hpp Trdn c i n true thap, cac CO ciu lam viec dde lap va dupc din ddng dien Qua trinh dieu khien su Idm vide cda mpt co eiu thyc chat la viee md may dpng co, ehuyen ddi tdc dp eung nhu phanh dimg ddng co cung he thdng chuyen dpng Do vay nghien edu v i qua trinh lam vide cda dpng co Id mpt viec lam quan trpng, anh hudng Idn de'n cau tao va chat lupng cua he thd'ng dieu khien Bing phuong phap thdng ke, phan tieh tren cac can true thdp cda cac hang e h i tao khac tren the gidi hien dang cd mat tai Viet Nam, cd the rut mpt sd kit luan v i yeu ciu dieu khien sU lam viec cda cac dpng eo dan dpng co c i u va toan bp ein true nhu sau 191' - Ddi vdi cac CO c i u edng tae cd khdi IUpng chuyen ddng Idn, momen can theo hai chieu quay la gidng nhU co eau di chuyen, co eiu quay thi tdc dp lam vide thudng nhd, cong suit dan ddng khdng Idn nen yeu eiu v i qua trinh khdi ddng va phanh dimg la quan trpng d cac CO ca'u nay, qua trinh tang (giam) tdc phai diin mpt each td tU va lien tue, thdi gian biin thien tdc dp la tuPng ddi dai (cd the den 30s).Tham ehi kit thue mpt pha lam viec, tdc dp dpng CP chua dat den tdc dp djnh mde Trong qua trinh md may, tde dp se dupe tang din lan lupt tUnhd din ldn Qua trinh phanh thi ngUpe lai De dap img cac yeu c i u tren, thudng sddung dpng CO day cudn vdi nhiiu cip dien trd dua vao maeh phin img cda dpng cP hoac sd dung dpng CO Idng sdc vdi bd bie'n ddi tin sd ddng dien hay bp biin ddi dien ap ddng dien cip cho dpng CO Tren mpt sd c i n tryc, qua trinh phanh dupe thUe hien khdng chi nhd phanh co ma cdn CO SUtrp gidp cua phanh dien bang each sd dung phUPng phap ham ngUpc - CP cau nang cd cdng suit tUong ddi Idn, cd 3-4 cap tdc dp lam vide khac Khoang dieu ehinh tde dp tuong ddi rpng, cd the den 1:10 Momen quay theo hai chiiu quay cda ddng CO la khac nhau, ddng dien md may Idn De dap dng dupe cac ydu c i u tren, cd nhiiu phuong phap khac nhu sd dung dpng cp day cudn kit hpp vdi dien trd dua vao mach rd to, dung dpng CP ehuyen dung cd cip tde dp, td hpp dpng cp-may phat-ddng cP mdt chiiu, td hpp hai dpng CP kit hpp vdi hdp giam tde hanh tinh-vi sai Qua trinh md may vd phanh ddng diu thuc hien theo nguyen t i c tang hay giam tdc dp lin lUpt td cap tdc dp be den Idn hoac ngUpe lai Qua trinh vat la qua trinh giai phong nang lupng vay trdn mpt sd ein tryc sd dung phuong phap ham dpng nang, ham ngupc - He thdng diiu khien phai cho phep ngudi van hanh thuc hien cac thao tac chuyen ddng thdng qua sU hoat ddng dpc lap cda cac co cau cdng tac nhU nang hg vat, quay, thay ddi tam vdi, di ehuyen de dua vat nang vao vj tri theo yeu ciu eung nhu giu vat d trang thai treo can thiet Kiim soat va dam bao eho ein true lam vide an toan thdng qua cac thiet bj an toan kieu eo, co-dien, eo-dien t d n h u + Han che tai trpng nang, hgn che mdmen tai, han che djch ehuyen cda may vd bd phan may ngoai vung cho phep, gidi han gde nghieng tay cin 48 TAP CHf KHOA HOC CONG NGHE XAY DUNG SO01-9/2007 + Ddng may khdng cho phep lam viec cac dieu kien an todn cho may va bd phan may bi pha va nhu; gid qua Idn, mat hoac lech pha dien ngudn cung cip NGHIEN Ciru C/NG DIJNG HE OIEU KHIEN BANG PLC CHO CAN TRUC THAP XAY Dl/NG VICOX- CTM80 Can true thap xay dyng VICOX- CTM80 Tdng cdng ty co xay dyng ehe tao lin d i u tien d Viet Nam C i n true cd sdc nang ldn nhat 60 kN t i m vdi nhd hon 14,5m va sdc nang d t i m vdi ldn nhat 50m la 13,2 kN Chiiu cao nang ein true d trgng thai dimg tu la 40,75m va d trang thai neo vao cong trinh la 80m Bing each sd dung ddng co k i t hpp vdi hop giam tdc hanh tinh-vi sai, co ca'u nang vat cd tdc dp lam viec: 3,75; 15 va 30 m/ph Cac ddng co lam viec theo trinh tu sau; Tde dp 1: 0C1 ldm viee theo chiiu nang vdi 725 v/ph, DC2 dimg; Tde dd 2; DCI lam viec theo chiiu nang vdi 725v/ph, OC2 quay cung chieu 1470v/ph; Tdc dp 3: DCI lam viec theo chieu nang vdi 1460v/ph, DC2 quay eung chiiu 2945v/ph; Khi lam vide vdi tai nang Idn hon 30 kN ehi eho phep eo cau lam vide d hai cip tdc dp nhd 15 va 3,75 m/ph Di ehuyen vat dpc theo tay ein nhd CP ca'u di chuyen xe cd hai c i p tdc dp Id 25 va 50 m/ph nhd ddng cO Idng sdc thay ddi sd ddi cyc td Co c i u quay ed hai cum dan dpng dpc lap Mdi cum co c i u quay gdm ed dpng CP Idng sdc thdng qua 01 hdp giam tdc dat dimg de giam tdc dp eho banh rdng din Do Mdmen quan tinh phin quay kha ldn, lya chpn phUPng phap thay ddi tdc dp dpng co bing thiit bj biin ddi t i n sd Tdc dd se dupe dieu khien mem thay ddi td 0-0,8 v/ph Phanh co cda ta't ca cac eo eiu deu la phanh dTa thudng ddng dUpc bd tri tren dudi true ddng co Md phanh bang ngudn chiiu He thdng diiu khien can tryc dupe nhdm tae gia thuc hien bao gdm cac mach sau; - Mach dien c i p ngudn dien chinh; - Mach chiiu sang; - Mach bao ddng su cd va cap ngudn dieu khien chinh; - Mach ddng lyc; + Mgch ddng lue CP c i u nang vat ddng md phdi hpp eho dpng eP theo cap tdc dp da neu d tren theo chieu quay nang va thdng qua su ddng ngat cda cac cdng tie to; + Maeh ddng lyc ddng co xe vdi cap tdc dp d hai chiiu quay, thay ddi bing sd ddi cyc td cda ddng co; + Mach ddng lUe ddng eo cda co c i u quay, gdm ddng co da'u song song dupc ndi vdi bien t i n de thay ddi tdc dp mem - Mach diiu khien bao gdm: mach diiu khien dpng cP nang ha, diiu khien dpng co xe con, dieu khien ddng eo co c i u quay va mach dieu khien kit ndi PLC - Mach ket ndi va cac hien thi TAP CHi KHOA HOC CONG NGHS XAY DUNG Sd01-9/2007 49 He thdng diiu khien cho cin true thap VICOX -CTM80 cd mdt sd dae diim chinh nhU sau: - Co eiu nang ed cap tdc dp Cip td'c dp nhanh nha't (td'c dp 3) ehl dirpc phep lam viec tai nang ehi bang 1/2 tai nang danh nghTa va dupc tu dpng khod Tay gat dieu khien cd vj tri nang tai, vi tri tai va vi tri Phanh dugc cai dat ddng tre vdi thdi gian t cd sy ehuyen ddi tdc dp de tranh giat tai Han ehi tai trpng Idn nha't dupe dua td PLC tdi va cai dat ndi tiep vdi dieu khien ddng co nang Han che tai trpng nang theo td'c dp nang Idn nhit cung dupc dua td mach PLC tdi cdi dat ndi tiep vdi mach dieu khie'n Sd dung Encoder lip tren true tang de han che chiiu cao nang tai va eung cip tin hieu eho PLC va td PLC chuyen tin hieu tdi hien thi dat ca bin - Co c i u di chuyen xe con; Viec chuyen ddi tdc dp dupc thUc hien bing cong tie chuyen ddi Cac han che hanh trinh kieu co dupe ddt tai gd'c va chan ein se ngit dien dpng eo keo xe theo chieu gay nguy hiem Tren true tang co ciu keo xe eon bd tri Encoder cung cip tin hieu dua v i PLC de xac djnh vj tri xe tren tay can (tam vdi) va qua dd cung cip eho hien thi vj tri xe bd tri ea bin - Co ciu quay; td'c dd cda hai dpng eo co ciu quay dupe dieu khien mem nhd mpt biin tan kieu gian tiip Gidi han gde quay gdm cdng tic gidi han trai vd edng t i c gidi han phai khdng cho phep phin quay c i n true quay qua 360° Do phin quay cd mdmen quan tinh Idn nen qua trinh md may dupc keo dai vdi thdi gian kha Idn (din 15s), qua trinh ham sd dyng biin tin d chi dp tai, nang lupng ham dupe xa nhiet tren dien trd - He thdng an toan; + Han che tai trpng nang nhu da ndi d phan tren dupc lay tin hieu td dau luc (Load cell) dua vao PLC sau dd td PLC dUa tin hieu man hinh dat ea bin va kit hpp vdi mach dieu khien nang tai; qua tai thi mach se khdng hoat ddng Oau lyc dupe bd tri tren cum pu li ddi hudng cda cap nang va dupe khuech dai thong qua he thdng tay ddn + Han ehe Mdmen tai; dung phan mim cai dat PLC de ngit dien he thdng mo men tai Idn hon mdmen tai cho phep Cac thdng sd d i u vao la tai trpng nang Q dupe cap thdng qua Loadcell va tam vdi R thdng qua Encoder xac dinh vi tri xe Viec ngat dien he thdng dupc tien hanh nhUsau; * Neu xe eon dang mang tai va di ehuyen xa true quay cda may din mdmen tai Idn hon Mdmen tai eho phep M = Q R > [ M ] thi he thdng se tu dpng ngit chieu di ehuyen cda xe eon nhimg van cho phep di chuye'n chiiu vao; Niu xe dang d mdt vi tri nao dd, tien hanh nang tai khdi nen va din M=Q.R> M ] thi he thdng se ty dpng ngit chieu nang cua tdi nang, song van cho phep quay theo chiiu tai + He thdng tdc dp gid va ty dpng dtmg lam viee cda c i n true cd gid Idn tren cap Dung Sensor dat tren dinh thap de tdc dp gid va dua tin hieu v i PLC, td PLC dUa v i mach dieu khien ngudn dien ehinh d i cit maeh Lue cdi se keu va den sang 50 TAP CHf KHOA HOC CONG NGHE XAY DUNG SO01 - 9/2007 LAP TRiriH CAI DAT CHO PLC TREN HE DIEU KHIEN CAN TRUC THAP VICOX-CTM80 PLC thyc hidn chuong trinh theo chu trinh lap Mdi vdng ldp dupe gpi la vdng quet Mdi vdng quet dupc bit dau bing giai doan dpc du lieu td cac cdng vao vung bd dem ao, tiep theo Id giai doan thyc hidn ehuong trinh Sau giai doan thue hien chuong trinh Id giai doan truyin thdng ndi bd va kiem tra Idi Vdng quet dupc kit thuc bang giai doan ehuyen eae npi dung cda bd dem ao tdi cac cdng Lap trinh edi ddt cho PLC S7-200 S7-200 bieu diin maeh logic bang mpt day eae lenh lap trinh Chuong trinh bao gdm mdt diy cac lenh S7-200 thyc hien chuang trinh bit dau td lenh lap trinh dau tien va kit thuc d lenh lap trinh eudi mpt vdng quet Cach lap trinh cho PLC ndi ehung dya tren hai phuang phap eo ban: phuong phap hinh thang (Ladder logie,vie't tat la LAD) vd phuong phap liet ke lenh (Statement List, viet tat la STL) Phypng phap liet ke lenh md nhdm tae gia sd dyng la phupng phap the hien chUPng trinh dudi dang tap hpp cac cau lenh Mdi cdu Idnh chuong trinh, ke ca nhiimg lenh hinh thirc bieu diin mpt chde nang cda PLC De tao mdt chUOng trinh dang STL, ngUdi lap trinh c i n phai hieu rd phuong thdc sd dung bit ngan x i p eua logic S7-200 can ed vao dae diem ca'u tao, edng nghe hoat ddng va eae yeu eiu v i an toan hoat ddng cda ein true, tien hanh xdy dyng eae so dd khdi diiu khien sy lam viec cda timg co cau edng tae eung nhu xac djnh cac thdng sd dieu khien Cac so dd khdi dupc xay dung bao gdm; "xSc djnh toc dp gid", "xac djnh gde quay", "xac dinh vi tri xe con", "xae djnh chiiu cao nang", "xac dinh tai trgng trung binh", "diiu khiin nang", "diiu khiin ha", "diiu khiin xe vao", "diiu khiin xe ra", "diSu khiin quay phai", "diiu khiin quay trai" Mdt cae cdng vide quan trpng d i cd t h i tiin hdnh lap trinh cdi dat cho PLC la lya chpn thiit bj cam biin vd ehuin hoa tin hieu dieu khien Cae thiet bj cam biin gdm cd: cac Encoder xae djnh chiiu cao nSng va xac djnh vj tri xe con, Loadcell tai trpng, Sensor gid Vi du sau ddy cho thiy each lya chpn Encoder xac djnh vi tri xe so vdi gde la gidi han cda xe tgi chSn can (img vdi t i m vdi be nhit cda can true) nhu sau: Tin hieu xung td Encoder dUa vdo bd d i m tde dp eao HSC (High Speed Counter) cda PLC Bd HSC se dim dupe sd xung phat td Encoder, td dd xac djnh dupc vj tri hien tai cda xe eon Khi xe eon di phia d i u ein, bd HSC d i m tie'n (tang), xe eon di vao bp HSC d i m Idi, d vj tri t i m vdi nhd nhit, bp d i m HSC resert v i Encoder lua chpn cd dp phan giai 60 xung/vdng li'ng vdi mpt vdng quay cda tryc tang kdo xe cung Id mdt vdng quay eua Encoder, va dd de di chuyin hit quang dUdng dai L thi tang phai quay dupe n vdng tuong dng vdi sd xung ma HSC d i m dupe se la 60 x n Cung ed t h i chpn Encoder cd dd phan giai eao hon de tang dp chinh xac, song phai dam bao gidi han bieu diin gia trj max cda HSC Mdt vi du khdc trinh bdy each lua chpn va bd tri dau lue eho eo eau nang Theo so dd bd tri cap ndng vd bd tri diu lye tren ein true, cd t h i xac djnh dupe lyc tae dung vao Load cell td lyc eang cdp ndng Idn nhit Lyc Idn nhit tae dung len Loadcell tinh dupc la 480 daN Chpn Loadcell cd dai din 500 daN vdi he sd qua tai 150% Vdi gia trj dien dp day tai mV/V ta chpn ngudn eung c i p eho Loadcell 15 V, vay dien dp diy tai se la 15Vx2mV/V=30 mV, hay 500 daN tUong dng vdi 30 mV Khi tai trpng nang Q=60 kN thi se tuong img vdi didn ap d i u cda Loadcell se la 28.8 mV Chpn module tuong tU EM235 dd TAP CHi KHOA HOC C O N G NGH$ XAY DUNG SdOf-9/2007 51 phan dai 12 bit vdi dai tin hieu vao (0-50mV) tuong dng gia trj dupc sd hod la 0-32000 Do vay vdi tai trpng Q=60 kN (28,8mV) ta cd gia trj sd hoa la 18432 Loadcell cd cae thdng sd ky thuat sau: Loai TSC-500daN, dai 500daN; Rate Output; 2mV/V; Non repeability