Unofanira kuwana matanho matatu nemazvo. Chekutanga, tora chiratidzo chethermocouple zvakanaka pabhodhi. Chechipiri, vhara pid control loop nenguva yakakodzera uye dziviriro. Chechitatu, gadzirisa uye batanidza system kuti ive yakarurama.
Matambudziko akawanda anouya munzira. Zviratidzo zve microvolt zvinoda dhizaini yekumberi yakanyatsonaka. Kudonha kwemhepo inoungana pamwe chete uye kudonha kwemhepo kunobvisa kurongeka kwekuyera tembiricha. Ruzha runokanganisa kuverenga kwemhepo kwakaderera. Nguva yekufamba kwemhepo inokanganisa kugadzikana. Windup inokanganisa mhinduro yepid controller. Heater drive neDFM limits zvinoumba bhodhi rekupedzisira.
Gwaro iri rinoramba riri pamusoro pebhodhi uye richiziva nezvekugadzira. Rakanangana nemainjiniya emidziyo yemagetsi nemapoka ezvigadzirwa zvemagetsi vanogadzira michina yekudzora tembiricha. Uchawana matanho anoshanda edanho rega rega, kubva pakuwana masaini kuburikidza nekugadzirisa pid yakavharwa.
Zvitsva Zvitsva
Tanga nekushandisa thermocouple chaiyo uye cold-junction compensation kuti uderedze zvikanganiso zvekuyera.
Ita kuti chiratidzo chidiki chethermocouple chive chakasimba usati wachichinja kuita data redhijitari. Uyewo, shandisa marongerwo akanaka uye kupatsanura kuti ubvise ruzha.
Ita kuti PID loop ishande semuchina westate, ine nguva chaiyo, anti-windup, uye derivative filtering.
Gadzirisa chinodzora chePID nhanho imwe neimwe, uye yera nguva chaiyo yethermocouple kuti chinodzora chirambe chakasimba.
Edzai danho rega rega musati maisa zvese pamwe chete, uye nyorai data kuti rionekwe richichinja nekufamba kwenguva.
Kuwanikwa kweThermocouple Kumberi Kwemugumo
Mhando, MaRanges, uye Cold-Junction Compensation
Tanga nerudzi rwethermocouple, sezvo rwunosarudza resolution yako uye cold-junction compensation (CJC) targets. Pedyo netembiricha yemukamuri, rudzi rweK junction runoita angangoita 40 µV padhigirii rega rega reCelsius. Mhando J, K, E, naT dzese dziri pakati pe40–60 µV/°C. Chiratidzo chidiki ichocho chinoumba sarudzo yega yega muketani yako yekuwana data.
mhando | Seebeck coefficient | Chinangwa chekururama chakabhadharwa |
|---|---|---|
J, N | 40–60 µV/°C | ± 0.2 ° C |
K | ~40 µV/°C | ± 0.3 ° C |
T, E | 40–60 µV/°C | ± 0.3 ° C |
Unofanira kuisa cold junction pa terminal block inochengetedza tembiricha imwe chete. Sensor yePt100 yekupisa mukati me block iyoyo inotevera reference junction. Chengeta ma terminal ese ari maviri patembiricha imwechete, uye shandisa waya yekuwedzera ye thermocouple inoenderana nerudzi rwayo. Waya isingaenderane inoita junction yechipiri uye kukanganisa kwakavanzika kwe offset.
Cherechedza: CJC IC ine ±5% accuracy inogona kuwedzera kusvika ku0.5 °C ye offset error. Verenga chikanganiso ichocho usati wavimbisa nhamba ye system accuracy.
MaAmplifiers uye Delta-Sigma ADCs
Une nzira mbiri dzemberi. Amplifier yezvishandiso ine high common-mode rejection inopa ADC yakasiyana. Delta-sigma ADC ine PGA yakavakirwa mukati inoita kuti pave nekushanduka muchikamu chimwe chete. Nzira yeamplifier inokupa CMRR pamusoro pe100 dB uye inodzikisa pasi pe60 µV nezvikamu zvakaita seAD8495. Nzira yekushandura inokupa 24-bit resolution, digital filtering, uye on-chip temperature sensor yeCJC.
Kudonhedza kwe offset kunokoshawo sekudonhedza kwe offset. Ma amplifiers akagadzika e Chopper anochengetedza residue offset uye ruzha rusingawanzoitiki rwakaderera. Ma network e gain akachekwa ne laser anochengetedza gain drift pedyo ne5 ppm/°C. Rongedza mu software uchishandisa ma polynomials kana tafura yekutsvaga. Kudonhedza kwe component uye CJC sensor drift zvinowedzera, uye zvikanganiso izvi zvinogona kupfuura dhigirii imwe chete Celsius mumashandisirwo akaomarara.
Kuona Thermocouple Yakavhurika uye Kubata Zvikanganiso
Thermocouple yakatyoka kana yakasununguka inotaridzika sevoltage yakaderera inoshanda, uye PID loop yako ichashandisa heater nesimba rayo rose. Wedzera open thermocouple detection kumberi kwemberi. Kamhepo kadiki ke bias current kuburikidza nejunction, kana pull-up pane input, kunoita kuti pave nefault level yaunogona kuona. Firmware yako inofanira kubata iyo fault level sefault, kwete se cold reading. Bvisa output wobva waridza alarm. Edza nzira iyi pane yega yega data acquisition module yaunovaka.
Kuisa muDhijitari, Kusefa, uye Kuzviparadzanisa
Kusarudzwa kweADC uye Kurongeka
Chinoshandura 12-bit, 3.3 V chinoputsa chiratidzo kuita matanho angangoita 806 µV. Thermocouple yako inongofambisa makumi eµV padhigirii Celsius. Saka chinoshandura ichocho hachioni chinobatsira kunze kwekunge wawedzera gain. Tanga wawedzera chiratidzo ne instrumentation amplifier pagain 100 kusvika 1000, wobva wachiita digitally. Sarudza amplifier ine input offset iri pasi pe1 mV, bias current iri pasi pe1 pA, uye noise density iri pasi pe5 nV/√Hz pa1 kHz. Kune 24-bit system, total noise inofanira kugara pasi pe1 LSB. Izvi zviri pedyo ne0.3 µV pane ±10 mV sensor ine 2.5 V reference.
Kusefa uye marongerwo acho zvinosarudza kana resolution iyoyo ichiramba iripo. Isai anti-aliasing cutoff iri pedyo ne sampling rate yakakamurwa ne2.56. Chinangwa chekudzikisa 40 dB pahafu ye sampling rate. Shandisai NP0/C0G capacitors uye metal-film resistors dzine ±0.25% tolerance kana zviri nani.
Kudzidzira kuronga | Batsirwa |
|---|---|
Chengeta ma node ane impedance yakakwirira ari mapfupi | Inoderedza kubuda kwemvura, capacitance inodonha, uye pickup |
Isa mafirita eRC paADC pin | Inosefa ruzha pamberi pemugumo wepamberi |
Nzira dzinopinda dziri kure nemawachi uye maDC/DC inductors | Inoderedza kubatana muzviratidzo zve microvolt |
Shandisa mhete dzekuchengetedza pamadziro ane impedance yakakwira | Inovhara kubuda kwemvura kunokonzera kuverenga kwepasi |
Chengeta ndege imwe chete yepasi yakafanana | Inodzivisa mareferensi anoyangarara uye zvikanganiso zvekushandura |
Zano: Isa 1 µF draubling capacitors mukati me 2 mm kubva pa power pin yega yega, uye usambofa wakaisa ma traces pakati pemaburi epasi.
Kuparadzaniswa kweGalvanic kune Nzvimbo Dzine Ruzha
Makabati emaindasitiri anobata madhiraivha emota, marelay, uye ma sensor runs marefu. Kusiyana kwemagetsi epasi pakati pe thermocouple sheath nebhodhi rako kunosundira magetsi kumberi. Bvisa kana sensor yabata conductive hardware. Bvisawo kana cable runs ikaenda kure nemamita mashoma pedyo nekuchinja zvinhu. Zviitewo kana PC yemubati neheater zvikaita ruzha. Digital isolator mushure meADC inochengetedza divi re analog rakachena uye riri nyore.
Kuzviparadzanisa kunochinja bhodhi. Unoda mapuraneti epasi akasiyana pamusoro pechipingamupinyi uye nzvimbo yakaparadzana yedivi remunda. Unodawo daro rekuchera rinosvika padanho rako rekuchengetedza. Zvipingamupinyi zvinowedzera mutengo nekukwirira, saka zviise pakutanga kwehurongwa. Edza chipingamupinyi nekutarisa hipot panguva yekusimbisa. Log leakage current pane yega yega data acquisition module yaunotumira.
Kuitwa kwePID Control Loop
Muchina weNyika uye Nguva yeKutora Samples
Vaka denderedzwa semuchina wemamiriro ezvinhu. Imwe state inoverenga thermocouple, imwe inomhanya pid control algorithm , uye imwe inoisa output. Tumira data pakati pemamiriro ezvinhu kuburikidza ne serial communication panzvimbo pe global variables. Global variables inovanza timing bugs, uye serial channel inoita kuti uzive kuti kukosha kwega kwega kunoshanda riini. Pid controller yako inobva yashanda padata rine zera rinozivikanwa.
Nguva yekutora sampuli inosarudza kugadzikana. Sample inokurumidza kupfuura thermocouple time constant, uye loop inowana data idzva. Sample inononoka, uye loop inopindura kune tembiricha yekare. Kuderera kwe loop kunowedzera phase lag, uye phase lag inosundidzira pid controller ku oscillation. Enzanisa nguva yesample ne thermocouple time constant, wobva watarisa sarudzo iri pabhenji.
Kusefa Kunodzivirira Mafungu uye Kubvisa Mafungu
Windup inoparadza kudzora tembiricha kwakanyatsojeka. Chitofu chinoguta, chinosanganisa zvinhu chinoramba chichiwanda, uye chinotenderera chinobuda kana chikanganiso chadzoka. Sarudza nzira yekudzivirira kuputika woiisa panzvimbo yayo usati wagadzirisa chero chinhu.
chidobi | How akunoita | Hunhu hunokosha |
|---|---|---|
Kuverenga kwekare kumashure | Inotumira musiyano wezvakabuda wakazara-minus-unsaturated kumashure mu integrator | Zviri nyore, zvakachipa, zvinoshandiswa zvakanyanya muindasitiri |
Kubatanidza simbi | Inomisa musanganiswa kubva pakuvaka miganhu yakatarwa yapfuura | Zviri nyore, zvakachipa, zvakajairika muindasitiri |
Kuverengera kwakajairika kwekudzoka shure | Inotyaira mamiriro ese emukati nechiratidzo chakazara | Inoshanda kune chero odha yemutongi, hapana parameter yekutevera |
Kukanganisa pakuverengazve | Inoshanda kumashure kubva pane yakabuda yakazara kuti idzorezve ndangariro yemutongi | Inochengetedza denderedzwa iri rakanyatsogadziriswa, richinzwa zvikanganiso zvemuenzaniso |
Kushanda kwechinhu chinobuda kunoita kuti ruzha ruve rwakanyanya, uye thermocouple front end inogara iine zvimwe. Wedzera derivative filter kune pid control algorithm. Filter iyi inoderedza high-frequency gain uye inomisa output kuti isasvetuke pakuchinja kwe setpoint.
Zano: Tanga wava nekushanda zviri nyore pakudzima kana kudzora kwakaenzana. Tarisa sensor yekupisa ichitevera nzvimbo yakatarwa, wobva wawedzera mazwi ekubatanidza uye ekuwedzera rimwe nerimwe.
Kutanga Kushanda Kwekudzora Kwekutanga
Chivharo chakavhurika chinoshanda chinokudzidzisa zvinopfuura kudzora kwakapwanyika kwechidzitiro. Dhonza hita neruoko, nyora tembiricha, uye simbisa kuti algorithm yekudzora mhinduro inoverenga kukosha kwakakodzera. Wobva wavhara chidzitiro nekuwedzera kwakaenzana chete. Simudza kuwedzera kusvika mhinduro yashanduka, wobva wadzosera kumashure. Wedzera chiito chakakosha kubvisa kukanganisa kwemamiriro ekunze, uye wedzera chiito chinobva kune chimwe chinhu chete kana mhinduro yemagetsi ichiida. Maitiro aya akarongwa anochengetedza pid temperature controller ichifanotaurwa, uye inoita kuti shanduko yega yega inotevera ionekwe.
Gadzirisa maparamita ekudzora pid zvichienderana ne thermocouple time constant chaiyo, kwete datasheet guess. Pid temperature controller isingateereri time constant ye thermocouple icharwisa sensor yayo. Nyora kumhanya kwega kwega, uye enzanisa dynamic response pakati pe run. Real-time dynamic adjustment ye pid control parameters inofanira kunge iri mune imwe nguva inotevera, mushure mekunge fixed-gain pid control yave yakasimba. Bata pid controller senzira yekudzora mhinduro ine miganhu inozivikanwa, uye nyora miganhu iyoyo yeinjiniya anotevera.
Kushanda Kwemagetsi uye Heater Drive
Maitiro Ekubatanidza Kubuda Kwemutongi Wekupisa
Funga nezvedanho rekubuda sechikamu checheni yekuyera, kwete chimwe chinhu chaunowedzera pakupera. Paunobatanidza chinodzora tembiricha neheater inodzivisa kupisa, rega magetsi afambe nepakati peheater nenzira imwe chete. Mutemo uyu wenzira imwe chete inzira yakanaka yekubatanidza magetsi ekugadzirisa tembiricha. Nzira dzemagetsi dzinodzokera shure dzinowedzera ruzha uye dzinovhiringidza danho rekutyaira.
Dunhu remuganho rinodzivirira actuator nemudziyo unodziya. Isa magetsi akawanda zvichienderana nedatasheet reactuator uye kugona kweheatsink. Chinodzora chinobva chachengeta magetsi anobuda ari pasi pedanho iroro. Izvi zvinodzivirira kupisa kusingafadzi, uko heatsink isina simba inobvumira sensor yekupisa kutaura nezvekupisa kuri kukwira uye pid controller inotyaira magetsi akawanda, zvichiwedzera kupisa kwakawanda. Paunoisa waya pachinhu chinodzora kupisa panzvimbo inopisa, ronga muganho uyu usati wasarudza chinobatanidza.
Kuenzanisa Nguva uye Miganhu Yekuchengetedza
Kuenzanisa nguva kunoratidza nguva yekushanda nekushanda mukati menguva yekushanda kweseji kuti ipe simba rakatsetseka re0–100%. Isa nguva yekushanda kweseji kusvika pachikamu chimwe chete pamakumi maviri chenguva yekubatanidza. Zvishandiso zvemagetsi zvakaita serelay, contactors, uye solenoid valves zvinoda nguva yakareba yekushanda kweseji. Kushanda kweseji pfupi kunopa kutonga kuri nani, asi zvinopedza simba remagetsi uye zvinopfupisa hupenyu hwese.
Sarudzo yekutyaira | Kudzora kunaka | Kupfeka uye hupenyu | Kushandiswa kwakanakisisa |
|---|---|---|---|
Relay | Kutenderera kwakaomarara, kwenguva refu | Kupfekwa kwekubata kunoderedza hupenyu hwemuviri | Kutakura zvishoma nezvishoma kwemafuta |
SSR | Kutenderera kwakapfava, kwakapfava | Hapana vanhu vanofamba-famba | Zvidimbu zvakawanda zveheater |
Analog drive | Inopfuurira | Zvinoenderana nedanho remagetsi | Kudzora tembiricha zvakanaka |
Wedzera muganho wekutonga kwemaitiro anogona kukuvara kana kuva nengozi mumamiriro ezvinhu asina kunaka. Inoshanda yoga, kunze kwemugadziri wemaitiro akajairwa, uye inoshandisa relay yekusunga isina njodzi. Mushandisi anoigadzirisazve kana maitiro acho adzokera pamamiriro anogamuchirwa. Rudzi urwu rwekudzivirira rungada mvumo yemazinga, semuenzaniso Factory Mutual muUSA kana EN14597 muEurope.
Kuenderana kweSignali Yekubuda uye Miganhu Yezvakatipoteredza
Enzanisa chiratidzo chekubuda nemutoro usati waisa chinodzora tembiricha mukabati. Tarisa voltage ye coil, SSR input current, uye logic level zvichienderana nemutyairi. Simbisa chiyero chekupisa kwenzvimbo yechikamu chimwe nechimwe chiri muchikamu chekutyaira. Kupisa mukati menzvimbo kunoderedza chiyero che relay nema SSR, saka siya maringe.
Alarm yekubatidza uye ma outputs ekudzivirira zvinofanirwa kudzoserwa patsva zvisati zvadzimwa. Kugadzirisa patsva kunogona kubva pakiyibhodhi, digital input, kana link yekutaurirana. Kana chishandiso chisina ma outputs ekubatidza, wedzera ma external latching relays sevaranda ve internal non-latching relays. Edza nzira yega yega yekubatidza patsva panguva yekusimbisa system yekudzora.
Kugadzirisa, Kuedza Nguva Dzose, uye Kubatanidzwa
Nzira Dzinoshanda Dzekugadzirisa PID
Mumapurojekiti mazhinji, unogadzirisa pid controller nekuedza zvinhu uye kuona zvinoshanda. Mainjiniya anogadzirisa pid control parameters nemaoko uye anotarisa kuti system inopindura sei. Tanga neproportional gain, wobva wawedzera integral action, wozobva watora derivative action. Pid temperature controller isingatarise kuti sensor inokurumidza sei icharwisa feedback yayo. The thermocouple time constant inoisa kuti loop inokurumidza sei kuita, saka inoganhurira bandwidth yaunogona kusvika. Faster sensors inokutendera kuti ushandise targeted pid control. Time constant ye thermocouple inoumbawo dynamic response yaungatarisira. Feedback control inochengetedza loop bandwidth iri pasi pemuganho we sensor.
nzira | Zvaunoita | Best fit |
|---|---|---|
Kuedzwa nemaoko | Wedzera purofiti kusvika padanho repamusoro, wobva wadzokera shure | Zvizhinji zvezvigadziro zvebhenji |
Ziegler-Nichols | Chiyera purofiti yekupedzisira uye nguva | Mitoro yakagadzikana, yakatsetseka |
Yakavakirwa pamuenzaniso | Isa modhi yekutanga, wobva waverenga | Zvigadzirwa zvinodzokororwa |
Zano: Nyora run yega yega. Enzanisa mhinduro inochinja-chinja pakati perun usati wachinja magain.
Kuedzwa Kwenguva Dzose kweThermocouple
Haugone kuvimba nedatasheet value ye time constant ye thermocouple. Inoshanduka nemodhi uye nenzvimbo yekuyera. Shandisa nzira ye thermocouple time constant yekuedza: wedzera tembiricha, nyora mhinduro, uye tsvaga 63% point. Dzokorora bvunzo yenguva constant mu mounting chaiyo. Sisitimu ye thermocouple time constant yekuedza ine nhanho yakarongwa inopa mhedzisiro inodzokororwa. Isa mhinduro yega yega mu pid & tuning. Danho re thermocouple time constant yekuedza rinoratidzawo zvikanganiso zvekuisa. Nguva yega yega test constant inoda tembiricha yekutanga yakasimba. Sisitimu yako ye thermocouple time constant yekuedza inofanira kunyora data raw. Enzanisa nguva constant ye thermocouple isati yasvika uye yapera kuunganidza. Nguva inononoka constant ye thermocouple inoganhurira kutonga kwakaringana kwetembiricha.
Kubatanidzwa kweSisitimu, Kusimbiswa, uye DFM
Batanidza muzvikamu. Simbisa cheni yechiratidzo, wobva wavhura-loop output, wobva wavhara-loop tuning. Sisitimu yekudzora inopfuura nhanho yega yega iri nyore kugadzirisa. Tarisa kugadzikana kwepid uye kururama kwehuwandu hwese. Kuchinjana kweDFM kunokosha: kuiswa kwesensor, kupinda kweterminal, uye mapoinzi ekuyedza zvinokwidza mutengo. Mhanya bvunzo imwe chete yenguva dzose payuniti imwe neimwe pamutsetse. Sisitimu yekuyedza yenguva dzose yethermocouple iyo inochengeta drift inotsigira kusimbiswa kwenguva refu. Nyora thermocouple nguva inoenderana nechinhu chimwe nechimwe chinogadzirwa. Dzokorora bvunzo yenguva inoenderana nechinhu chimwe nechimwe mushure mekuchinja kweheater. Sisitimu yako yekuyedza nguva inoenderana nethermocouple inofanira kuchengetedza mhinduro yenhanho. Pid controller yakagadziriswa kune nguva inoenderana nethermocouple isina kukodzera ichachinja. Kudzora mhinduro kunoenderana nedata rechokwadi resensor. Pid controller inoda nguva inozivikanwa yemuenzaniso. Kuyerera kwekuyera tembiricha kunoratidzwa mukuyedza kwenguva inoenderana. Log data yekuyera tembiricha panguva yega yega yekumhanya. Sisitimu yekuyedza nguva inoenderana nethermocouple inofanira kuratidza masensor akavhurika.
Funga nezvekuvakwa kwechinhu sekutarisa. Kutanga, unosarudza mhando yemberi uye sarudzo yeCJC, wozobva wasarudza amplifier kana ADC ine filtering. Unowedzera isolation chero kupi zvako kwaunoda kabhineti. Unoisa state-machine loop timing, anti-windup, uye derivative filtering. Unoyera miganhu ye output drive uye safety. Unopedzisa ne tuning uye thermocouple time constant test.
Edza danho rega rega rega usati wabatanidza zvizere. Tanga waratidza cheni yechiratidzo, wobva waratidza kubuda kwe open-loop, wobva waongorora pid yakavharwa. Pid controller inopfuura danho rega rega iri nyore kugadzirisa.
Nyora nguva dzese dzauri kufamba. Tarisa uchiongorora tembiricha nekufamba kwemavhiki. Tsika iyoyo inoshandura chinhu chinodzora tembiricha chinoshanda kuita chaunogona kuvimba nacho. Kudzora kwako mhinduro kuchakupa mubayiro wekutarisira.
FAQ
Mari yangu yekubhadharisa mari inofanira kunge yakarurama zvakadii?
Enzanisa kurongeka kweCJC nehurongwa hwako. CJC IC ine ±5% kurongeka inogona kuwedzera kusvika ku0.5 °C yekukanganisa kwe offset. Verenga kukanganisa ikoko usati wavimbisa nhamba yekurongeka kwehurongwa. Chivharo che terminal che isothermal chine sensor yePt100 chinobata reference junction zvakasimba uye chinoita kuti kukanganisa ikoko kuve kudiki.
Ndirini pandinofanira kuisirwa galvanic isolation kumberi kwemba?
Isa parutivi kana sensor yabata hardware inofambisa magetsi. Isa parutivi kana tambo ichifamba inopfuura mamita mashoma pedyo nekuchinjana zvinhu. Isa parutivi kana PC yemubati neheater zvikaita ruzha. Chinobvisa magetsi chedhijitari mushure meADC chinochengetedza divi reanalog rakachena.
Sei simba remuchina wangu wekupisa richidarika nzvimbo yakatarwa?
Windup ndiyo inowanzo kukonzera. Heater inoguta, integrator inoramba ichikura, uye loop inodarika kana error ikadzoka shure. Wedzera anti-windup usati wagadzirisa. Kuverenga kumashure kana integrator clamping zvese zvinoshanda. Wobva waisa derivative filter kuitira kuti ruzha rusakwire kubuda.
Ndingayera sei nguva ye thermocouple constant?
Isa tembiricha, nyora mhinduro, uye tsvaga poindi ye63%. Dzokorora bvunzo iyi mukuisa chaiyo, nekuti kukosha kwedatasheet hakuzoenderane neassembly yako. Isa mhinduro yega yega mukugadzirisa. Nguva inononoka inodzora bandwidth ye loop yaunogona kusvika.
Cherechedza: Edza danho rega rega rega usati wabatanidza zvizere. Tanga waratidza cheni yechiratidzo, wozobva waratidza kubuda kwe open-loop, wozobva wagadzirisa closed-loop.
