Yadda Tsarin PLC da DCS Ke Taka Rawa Wajen Ingantaccen Automatikan Daidai a Masana’antar Kera Motoci
Masana’antar kera motoci na daya daga cikin muhimman muhallan da ke bukatar tsarin kula da masana’antu (industrial control systems) masu tsananin inganci, suna bukatar saurin sarrafa “discrete logic” da kuma haɗin kai mara tangarda na tsarin aikin sinadarai da tsari (process). Programmable Logic Controllers (PLCs) da Distributed Control Systems (DCS) su ne ginshiƙan fasahar da ake gina zamani na samar da motoci a kai. Fahimtar tsarin gine-ginen su na fasaha, yarjejeniyar sadarwa (communication protocols), da hanyoyin haɗa su wuri guda (integration methodologies) abu ne mai muhimmanci ga injiniyoyi da ke da alhakin ƙirƙira, aiwatarwa ko sabunta layukan kera motoci. Wannan makala tana ba da bayanai na fasaha game da yadda waɗannan tsarin ke aiki, yadda suke mu’amala da juna, da irin ribar aiki da suke kawowa da a iya aunawa.
Gine-ginen PLC: Scan Cycle, Ladder Logic, da Ƙuntatawar Real-Time
A matakin kayan aiki (hardware), PLC na ƙunshe da wutar lantarki (power supply), “central processing unit (CPU)”, ƙwaƙwalwa (memory), da kuma modules na shigarwa/fitarwa (input/output – I/O). CPU na aiwatar da “scan cycle” mai ci gaba wanda ya ƙunshi matakai uku: karanta yanayin shigarwa, aiwatar da shirin mai amfani, sannan sabunta yanayin fitarwa. A fannoni na mota, lokaci na scan yakamata yawanci ya kasance ƙasa da millisecond 10 domin tabbatar da cewa tsarin yana da saurin amsawa ga injuna masu motsi da sauri. Masu shirye-shirye suna amfani da “ladder logic” ko “structured text” akai-akai don gina “control algorithms”. Injiniyoyi dole su yi la’akari da mafi tsawon yiwuwar lokaci na scan lokacin da suke tsara “safety interlocks”; misali, injin “press brake” yana bukatar amsar fitarwa nan take, don haka ana yawan zaɓar shirye-shiryen da ke amfani da “interrupt” ko kuma “safety PLCs” na musamman da ke da tsarin maimaitawa (redundant architectures).
Sabbin PLCs daga kamfanoni irin su Siemens (SIMATIC S7-1500), Rockwell Automation (ControlLogix), da Mitsubishi Electric (MELSEC iQ-R) suna zuwa da “multi-core processors” masu iya ɗaukar aikin daidaitaccen sarrafawa da kuma ayyuka na ci gaba kamar “motion control” da haɗa tsarin hangen nesa (vision system integration) a lokaci guda. Lokacin zaɓar PLC don wani tashar aiki takamaimai, injiniyoyi suna tantance yawan I/O, buƙatar saurin sarrafawa, ire-iren hanyoyin sadarwa da ake buƙata, da kuma matsayin juriya ga yanayi. Don misali, a shagunan fenti (paint shop), PLCs dole su jure sinadarai masu tsanani da yiwuwar yanayi mai fashewa, wanda ke buƙatar “IP67 enclosures” ko shingayen tsaro na ciki (intrinsic safety barriers).
Gine-ginen DCS: Rarraba Aikin Sarrafawa da Tsakiyar Kula da Tsari
DCS yana bambanta da PLC ɗin da ke aiki shi kaɗai ta hanyar tsarin sarrafawa da aka rarraba (distributed processing architecture). Maimakon dogaro da mai sarrafawa guda ɗaya a tsakiya, DCS yana rabawa da yawa “controllers” a ko’ina cikin masana’anta, kowanne yana kula da wani yanki na tsari, yayin da suke aika rahoto zuwa tashoshin kulawa na tsakiya (central supervisory stations). Wannan tsari yana ba da kariyar maimaitawa ta dabi’a (inherent redundancy); idan mai sarrafawa guda ya ƙi aiki, waɗanda ke makwabtaka da shi suna ci gaba da aiki, kuma tsarin kulawa na tsakiya yana sanar da ma’aikata nan take. Ga masana’antar kera motoci da ke shimfiɗa a ɗaruruwan dubban “square feet”, wannan tsarin rarrabawa yana rage kuɗin wayoyi da kuma maida da’irar sarrafawa kusa da inda ake aiki (localizing control loops).
Matakin kulawar DCS (supervisory layer) yana samar da aikin “historian”, wato adana bayanan samarwa na shekaru da “resolution” na daƙiƙa ko ma millisecond. Injiniyoyi suna amfani da waɗannan bayanai wajen binciken asalin matsala (root cause analysis) idan an samu lahani. Misali, idan aka gano wata mota na da matsalar haɗa walda bayan watanni shida da ƙera ta, injiniyoyi za su iya bincika “DCS historian” don gano daidai saitunan walda, matsayen robot, da yanayin muhalli a lokacin. Wannan irin bin diddigi (traceability) ba zai yiwu ba sai da ingantacciyar haɗa DCS.
Yarjejeniyoyin Sadarwa: Ginshiƙin Haɗaɗɗen Automatika
Nasarar haɗa PLC da DCS ya dogara ƙwarai kan zaɓar yarjejeniyar sadarwa ta masana’antu da ta dace. PROFINET, EtherNet/IP, da EtherCAT su ne suke mamaye sababbin shigarwa saboda babban “bandwidth” da ɗabi’ar “deterministic”. PROFINET IRT (Isochronous Real-Time) na cimma lokaci na zagaye ƙasa da millisecond 1, wanda yake da matuƙar muhimmanci don daidaita motsin ginshiƙai da yawa (multi-axis motion) a tashoshin “body-in-white”. EtherNet/IP, wanda ke amfani da na’urorin Ethernet na gargajiya, yana sauƙaƙa haɗawa da tsarin kasuwanci (enterprise systems) yayin da yake kiyaye aikin real-time ta hanyar CIP Sync don daidaita lokaci.
Tsoffin yarjejeniyoyi (legacy protocols) har yanzu suna yawaita a tsofaffin gine-gine. PROFIBUS DP har yanzu yana haɗa na’urori da dama a filin aiki, wanda ke buƙatar “gateways” don haɗawa da sabbin dandamalin DCS. Modbus TCP/IP yana ba da zaɓi mai sauƙi kuma bude (open) don haɗa na’urorin ɓangare na uku irin su “variable frequency drives” da “power monitors”. Injininyoyi da ke tsara sabuntawa dole su binciki tsarin “fieldbus” na yanzu sosai su kuma fayyace ire-iren hanyoyin sadarwa da suka dace don gujewa sake jera wayoyi da zai yi tsada.
OPC Unified Architecture (OPC UA) ta zama mafita mafi soyuwa don haɗin tsaye (vertical integration). OPC UA servers da aka saka a cikin PLCs suna buɗe daidaitattun samfurin bayanai (standardized data models) ga matakan DCS da MES (Manufacturing Execution Systems). Wannan sadarwa mai tsaro kuma mai zaman kanta da dandalin kwamfuta (platform-independent) yana ba da damar musayar bayanai ba tare da la’akari da irin mai sarrafawa ba. Yawancin manyan masu ƙera motoci (automotive OEMs) yanzu suna wajabta bin ƙa’idojin OPC UA ga duk sabbin kayan aiki da suke saya.
Safety Instrumented Systems: Haɗa Tsaron Aiki (Functional Safety)
Masana’antar kera motoci na ƙunshe da manyan haɗari daga “robotic workcells”, manyan injinan bugawa (high-energy presses), da “automated guided vehicles”. Safety Instrumented Systems (SIS) suna magance waɗannan haɗurra ta amfani da “safety PLCs” na musamman da suka dace da ƙa’idojin ISO 13849 ko IEC 61508. Waɗannan masu sarrafa tsaro suna aiki ne daban da PLCs na daidaitaccen sarrafawa, suna sa ido kan tabarmar tsaro (safety mats), “light curtains”, da da’irar gaggawar tsayawa (emergency stop circuits). Idan an take wani sharadin tsaro, suna fara rufe tsarin cikin sarrafaffen hanya a cikin millisecond, ba tare da dogaro da tsarin sarrafawa na asali ba.
Haɗa tsarin tsaro da DCS na kawo ƙalubalen fasaha. Injiniyoyi dole su tabbatar cewa an rubuta abubuwan da suka shafi tsaro a “DCS historian” don binciken al’amura ba tare da rage ingancin tsaro ba. A yawanci ana yin haka ne ta hanyar sadarwa ta hanya ɗaya (one-way communication) daga safety PLCs zuwa DCS ta amfani da yarjejeniyoyin sadarwa na tsaro irin su PROFIsafe ko CIP Safety. Safety PLC na aiko bayanin matsayi (status) zuwa DCS, amma DCS ba zai iya shafar aikin tsaro ba. Aiwarar da ta dace na buƙatar haɗin kai tsakanin injiniyoyin sarrafawa da kwararru a fannin tsaro tun a matakin zane.
Wani babbar masana’antar kera motoci ta Jamus kwanan nan ta aiwatar da tsarin “safety-over-EtherCAT” a duk sabuwar layin haɗa motoci na lantarki. Wannan hanya ta rage wayoyi da kashi 40% idan aka kwatanta da tsoffin da’irorin tsaro na “point-to-point” tare da cimma takardar shaidar Safety Integrity Level 3 (SIL3). Safety PLCs suna sadarwa kai tsaye da DCS na tsakiya ta OPC UA, suna ba da damar ganin matsayin tsaro na real-time ga ma’aikatan shuka.
Darasin Aiki: Haɗin Siemens TIA Portal a Cikin Haɗa Injin
Wani shukar haɗa injin mota (engine assembly plant) a Bavaria da ke kera raka’a 1,200 a rana ta fara cikakken sabuntawar automatika da Siemens ke tsakiya. Tsarin da ke akwai a baya ya ƙunshi PLC-5 da S7-300 masu zaman kansu ba tare da cibiyar da ke ba da cikakken hange ba. Injiniyoyi sun ƙayyade sabon tsari ta amfani da SIMATIC S7-1518 don tashoshin saurin aiki (misali saka camshaft, matse “bearing cap”) da ET 200SP na rarrabaccen I/O don sarrafa kayan motsi. Totally Integrated Automation (TIA) Portal ta samar da dandalin injiniya guda ɗaya ga duk “controllers”, ta rage lokacin shirye-shirye da kashi 30%.
Matakin DCS ya yi amfani da SIMATIC PCS 7, yana haɗa PLCs 78 a cikin modules 12 na samarwa. PROFINET tare da IRT ya ba da damar daidaitaccen saka camshaft da crankshaft, yana kiyaye daidaiton juyawa na +/- digiri 0.1. WinCC SCADA ta ba ma’aikata damar kallon “dashboards” na musamman da ke nuna “overall equipment effectiveness (OEE)” bisa tashar aiki, canjin shift, da irin samfurin mota. Cikin shekara guda, ingancin layin gaba ɗaya ya tashi daga 76% zuwa 85%, wanda ya nuna ƙarin injuna 108 a rana ba tare da kashe kuɗi wajen ƙara sababbin tashoshin haɗawa ba.
Jagorar Aiwarar Fasaha: Haɓakawa Daga PLC Kaɗai Zuwa Haɗaɗɗen PLC-DCS
Ga injiniyoyin da ke shirin sauya daga tsarin da PLC kaɗai ke sarrafawa zuwa tsarin haɗaɗɗen PLC-DCS, waɗannan matakan fasaha na gaba suna ba da tsari mai ma’ana:
Mataki na 1: Lissafi da Bita (makonni 4-6)
Fara da rubuta bayanin duk masu sarrafawa da ke akwai, ka lura da masana’anta, samfurin (model), sigar firmware, da nau’in hanyoyin sadarwa. Ƙirƙiri zane na tsarin hanyar sadarwa (network topology) da ke nuna yadda masu sarrafawa ke haɗuwa a halin yanzu. Kimanta ragowar rayuwar aiki da samuwar kayan gyara (spare parts) ga kowane mai sarrafawa. Fara fifita masu sarrafawa da suka kusa tsufa ko daina samuwa don musanya su da wuri.
Mataki na 2: Sabunta Tsarin Hanyar Sadarwa (makonni 8-12)
Saka “industrial Ethernet switches” masu “Quality of Service (QoS)” don fifita zirga-zirgar bayanan real-time. Gina tsarin hanyar sadarwa da aka raba (segmented network architecture) wanda ya bambanta zirga-zirgar sarrafawa daga bayanan kasuwanci. Saita VLANs don ware sel ɗin samarwa, domin hana yaɗuwar matsala daga wuri zuwa wuri. Saka “firewalls” tsakanin cibiyoyin sarrafawa da na kasuwanci bisa ga shawarwarin tsarin Purdue na ISA-95/IEC 62264.
Mataki na 3: Zaɓin Dandalin DCS da Gwajin Pilot (makonni 12-16)
Zaɓi dandalin DCS da ya dace da yarjejeniyoyin PLC da kake da su. DeltaV na Emerson, System 800xA na ABB, da Experion na Honeywell duk suna da manyan “protocol libraries”. Fara aiwatarwa a kan layin samarwa guda ɗaya, ka haɗa har zuwa PLC guda biyar. Tabbatar da aikin “historian”, gudanar da ƙararrawa (alarm management), da iya fitar da rahoto kafin faɗaɗa shirin.
Mataki na 4: Daidaita Masu Sarrafawa da Sauyawa (Na ci gaba)
Ƙirƙiri jadawalin sauya tsoffin PLCs a matakai, ka bai wa fifiko waɗanda ke da yawan gazawa ko ƙarancin damar tantance matsala (diagnostics). Daidaita kan dandalin PLC ɗaya ko biyu kawai don sauƙaƙe shirye-shirye da kulawa. Ƙirƙiri “standardized function blocks” don ayyuka gama gari (misali sarrafa conveyor, sa ido kan press, tabbatar da torque) don tabbatar da cewa tsarin na aiki iri ɗaya a ko’ina cikin masana’anta.
Mataki na 5: Aiwarar Advanced Analytics (watanni 6-12 bayan DCS)
Da zarar an tara isasshen tarihi na bayanai, fara aiwatar da “predictive algorithms”. Misali, nazarin lanƙwasa torque daga PLCs na matse kusoshi (fastening PLCs) don gano kayan aikin da ke buƙatar daidaitawa (calibration) kafin su fara samar da matsewar da ba ta cika ka’ida ba. Aiwatar da “machine learning models” a cikin DCS ko dandalin nazari da aka haɗa domin gano ƙananan alamu da idon ma’aikaci ba zai iya gani ba.
Batutuwan Fasaha na Musamman ga Samar da Baturi Mai Babban Wuta
Juyawa zuwa motoci na lantarki ya kawo sababbin ƙalubale a fannin automatika, musamman a haɗa batura (battery module da pack assembly). Tsarin babban wuta (high-voltage) yana buƙatar shirye-shiryen PLC na musamman don sarrafa jerin kunnawa na contactor, sa ido kan keɓewar wuta (insulation monitoring), da sarrafa zafi (thermal management) yayin “formation cycling”. Injiniyoyi dole su aiwatar da maimaita sa ido na tsaro (redundant safety monitoring) ga “DC bus voltages” da suka haura 800V, sau da yawa ta amfani da safety PLCs da ke da takardar shaidar “function blocks” don gano wuta (voltage detection).
Bangaren “battery formation”, inda ake kai cells cikin jerin caji da fitar da caji a karkashin kulawa, yana bukatar sarrafa zafin jiki daidai (±1°C) a kan ɗaruruwan tashoshi a lokaci guda. Tsarin DCS na iya yin fice a nan, yana daidaita manyan kabad ɗin formation da PLC ke sarrafawa yayin da yake kiyaye bin diddigin bayanai a tsanake da ake bukata don batun garantin kaya. Dole ne a haɗa bayanin formation na kowane cell da lambar ganewa ta ƙarshe ta mota (vehicle identification number), wanda ke buƙatar ƙarfi sosai wajen haɗa DCS historians da tsarin MES na sama.
Wani shukar baturin EV a Arewacin Amurka ta aiwatar da DCS na Emerson tare da DeltaV controllers don sarrafa yankin formation. Tsarin yana kula da tashoshi 2,500 na formation a lokaci guda, yana tattara bayanan wuta (voltage), ƙarfi (current), da zafin jiki duk millisecond 100. Wannan bayanin da ya yi zurfi yana ba da damar gano cells masu halayya marar kyau da wuri, yana hana su shiga layin haɗa motoci. Masana’antar ta ruwaito raguwar matsalolin baturi a fili (field failures) da kashi 94% masu alaƙa da ingancin cells tun bayan aiwatar da tsarin.
Tambayoyi na Fasaha da Ake Yawan Yi
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Ta yaya zan tantance daidaitaccen scan time don wani aikace-aikacen mota na musamman?
Ka ƙididdige lokacin amsa da ake bukata ta hanyar nazarin halayen tsarin (process dynamics). Ga ayyukan “high-speed pick-and-place”, scan time ƙasa da millisecond 5 yana da matuƙar muhimmanci. Ga conveyors na jigilar kaya, millisecond 20-50 ya wadatar. Auna mafi tsawon lokacin aiwatar da shiri (worst-case program execution time) ta amfani da kayan aikin bincike na PLC sannan ƙara kashi 20% na kariyar tazara. Ka yi la’akari da amfani da I/O na “interrupt-driven” don ayyukan tsaro masu muhimmanci maimakon dogaro da amsar scan cycle kawai. -
Wane irin tsarin redundancy kuke ba da shawara ga layukan samar da motoci masu matuƙar muhimmanci?
Ga layukan walda na “body-in-white” inda tsayawar aiki ke iya janyo asarar fiye da dala $20,000 a awa guda, ka aiwatar da tsarin redundant CPU tare da “automatic failover”. Siemens S7-1500R/H systems suna ba da “bumpless redundancy” ga hanyoyin PROFINET. Ga yankunan haɗawa da ba su da matuƙar muhimmanci sosai, redundancy a matakin na’ura (device-level redundancy) – kamar maɓuɓɓugan wuta biyu (redundant power supplies), “network switches” biyu – sau da yawa yana ba da wadatacciyar sahihanci (reliability) a ƙananan kuɗi. Ka tabbata ka rubuta lokutan sauyawa (switchover times) yayin “commissioning” don tabbatar da cewa sun dace da bukatun samarwa. -
Ta yaya zan tafiyar da daidaita lokaci (time synchronization) a tsakanin PLCs da DCS servers da dama?
Ka aiwatar da stratum-1 NTP time server da aka daidaita da GPS ko agogon atomic. Saita duk PLCs, DCS servers, da na’urorin cibiyar sadarwa a matsayin NTP clients. Ga aikace-aikacen da ke bukatar daidaituwar lokaci ƙasa da millisecond (misali multi-axis gantries, synchronized pressing operations), yi amfani da IEEE 1588 Precision Time Protocol (PTP) tare da boundary clocks da suka dace. Tabbatar da daidaiton lokaci yayin commissioning ta amfani da “protocol analyzers”.
