04 Power Drive: Mlatho wa MOS wa Magawo Atatu Umazindikira Mphamvu ya Torque Yotuluka ya Joint

Chithunzi 5: Mawaya a mota a magawo atatu amalumikizidwa pakati pa gawo lamagetsi la MOS, ndi zotsukira zitsanzo, madalaivala ndi zigawo zosefera zomwe zayikidwa mozungulira.

 

Choyendetsa cholumikizira ichi chapangidwira ma mota opanda maburashi a magawo atatu. Kuwongolera kwapamwamba kwa ma mota a BLDC a magawo atatu nthawi zambiri kumafuna ma half-bridge atatu, kupanga inverter ya magawo atatu yokhala ndi ma MOSFET amphamvu osachepera asanu ndi limodzi. Zipangizo zambiri za MOS zazikuluchitsuloiwonekere pa PCBA yozungulira malo otulutsira magetsi a magawo atatu, mogwirizana ndi kapangidwe kameneka.

 

Mfundo yogwiritsira ntchito mlatho wa magawo atatu ikhoza kuchepetsedwa motere:

Voliyumu ya batri kapena basi imalowetsedwa kudzera pa P+ ndi P-; Kusintha kwa liwiro la MOS half-bridges kumasintha voltage ya DC kukhala mphamvu yamagetsi ya magawo atatu;

Mphamvu yamagetsi ya magawo atatu imalowa mu ma windings a mota kuti ipange mphamvu ya maginito yozungulira; Wowongolerayo amasintha nthawi zonse ma cycles a PWM kutengera malo olembera ndi mayankho amagetsi;

Pomaliza pake zimathandiza kuti cholumikizira chitulutse mphamvu, liwiro kapena malo.

Kapangidwe kolakwika ka gawoli kamabweretsa mavuto angapo wamba: kutentha kwambiri kwa MOS, kugwedezeka kwa liwiro lotsika, kugwedezeka kwakukulu kwa torque, kuyambitsa chitetezo chabodza cha overcurrent, ndi kusokonezeka kwa EMI komwe kumakhudza ma encoders kapena ma communication circuits. Pachifukwa ichi, kapangidwe ka power board ka maloboti ndi kovuta kwambiri kuposa ka board wamba kakang'ono ka motor driver.

 

Chithunzi 6: Chowongolera magetsi cha TLV767 chikuwoneka pa bolodi, pamodzi ndi ma inductor, ma capacitor ndi zigawo zingapo zamphamvu zochepa.

Mtengo wamagetsi ndi wofunikanso kuunikanso. Ma regulator a LDO monga TLV767 ndi ma inductors amphamvu olembedwa kuti "100" amawonekera pa PCB. Poganizira momwe ma joints a 48V amagwiritsidwira ntchito, zitha kuganiziridwa kuti makina otsika mphamvu sangatengedwe mwachindunji kuchokera ku magetsi okwera kudzera mu ma LDO okha. M'malo mwake, kapangidwe ka magetsi kofanana ndi kameneka kagwiritsidwa ntchito:

Basi yamagetsi amphamvu kwambiri → Kusintha kwa ma step-down → Ma rail amagetsi otsika (5V / 3.3V, ndi zina zotero) → Malamulo achiwiri a LDO / kusefa phokoso lapafupi

Kapangidwe ka mphamvu kameneka ndi koyenera. Ma MCU, encoder, ma sampling amplifier ndi ma transceiver olumikizirana amafunika mphamvu yoyera komanso yokhazikika yamagetsi otsika, pomwe ma switch a MOS ndi mizere ya gawo lamagetsi amapanga phokoso lalikulu. Ngati magetsi otsika alibe mphamvu yokwanira yoletsa kusokonezedwa, zolakwika zoyamba kuonekera nthawi zambiri si zolakwika zamagalimoto, koma kulumpha kwadzidzidzi kwa ngodya, kusiya kulumikizana kapena kuwerenga kwa ma sampling amagetsi.

05 Kuzindikira Zamakono ndi Kutentha: Maloboti Olumikizirana Ayenera Kuyang'anira Torque Yotuluka Mu Nthawi Yeniyeni

 

Chithunzi 7: Ma resistors ambiri a R001 otsika mtengo ali pansi pa gawo la mphamvu la magawo atatu.

Zigawo za R001 ndizofunikira kwambiri pa bolodi ili, zomwe zikuyimira ma resistors otsika mtengo a miliohm-level (1 mΩ nthawi zambiri) omwe amagwiritsidwa ntchito poyesa mphamvu yamagetsi kapena mphamvu yamagetsi ya basi. Kuzindikira mphamvu yamagetsi kumapanga maziko a ulamuliro wotsekedwa wa maloboti, chifukwa mphamvu yotulutsa ya mota ya BLDC imagwirizana kwambiri ndi mphamvu yake yamagetsi yamagetsi.

Mwa kuyankhula kwina, chowongolera sichimaganiza "za" mphamvu ya cholumikizira; m'malo mwake, chimawerengera mphamvu yamagetsi poyesa kutsika kwa mphamvu yamagetsi pang'ono kudutsa ma resistors a sense:

Kutsika kwa voliyumu kudutsa choletsa kumva → Kukula ndi kusefa → Kusankha zitsanzo za ADC → Kuwerengera kwamakono → Kulamulira kwa torque ya FOC

Kulondola kwa unyolo wa chizindikiro ichi kumakhudza mwachindunji:

Kulondola kwa Kulamulira kwa Torque: Ngati kuyerekezera kwamakono sikuli kolondola, kutulutsa kwa torque sikudzakhala kolondola.

Kusalala kwa Liwiro Lochepa: Phokoso lalikulu la zitsanzo limayambitsa kugwedezeka pa liwiro lochepa.

Chitetezo Chopitirira Muyeso: Kuyankha pang'onopang'ono kungayambitse kuyaka kwa MOSFET, pomwe zosintha zowopsa kwambiri zimapangitsa kuti pakhale zoyambitsa zodzitetezera zabodza.

Njira Yoyendetsera Kutentha: Mphamvu yamagetsi yokhazikika imabweretsa kukwera kwa kutentha kwa ma mota, ma MOSFET ndi ma current-sense resistor nthawi imodzi.

Kuchokera pamalingaliro a kapangidwe kake, kuyika zotsutsana ndi mphamvu yamagetsi pafupi ndi ma MOSFET ndi mawaya amagetsi kumafupikitsa kuzungulira kwa mphamvu yamagetsi yapamwamba, zomwe zimathandiza kuchepetsa kulowerera kwa parasitic ndi zolakwika za sampuli. Chiwerengero chachikulu cha zotsutsana ndi ma capacitor ang'onoang'ono zimayikidwa pafupi ndi gawo lililonse, zomwe nthawi zambiri zimagwiritsidwa ntchito poletsa chipata, kusefa sampuli, kukhazikika kwa driver ndi kugawa malo.

Kuzindikira kutentha n'kofunika kwambiri. Chizindikiro cha MOTOR NTC chimasonyeza thermistor yomwe yaikidwa mkati mwa mota kapena pafupi ndi ma windings. Pa malo olumikizirana a robot okhala ndi anthu, kugwira ntchito kwa torque yothamanga pang'ono, kugwira ntchito mosasunthika kwa nthawi yayitali, komanso kugwedezeka kwakanthawi panthawi yoyimirira kapena kudzuka zonse zimapangitsa kutentha kukwera kwambiri. NTC imalola wowongolera kuchita ntchito zitatu zofunika kwambiri zokhudzana ndi kutentha:

Kuchepetsa Mphamvu ya Mphamvu: Chepetsani mphamvu yamagetsi yotulutsa mphamvu kwambiri pamene kutentha kukukwera; Kuchepetsa Mphamvu ya ...

Kutseka koteteza: Lowani mu modi yolakwika kutentha kukapitirira malire a chitetezo.

Ichi ndi luso lofunikira lomwe ma robot odziwa bwino ntchito ayenera kukhala nalo. Popanda kulamulira kutentha, cholumikiziracho sichingagwire ntchito modalirika kwa nthawi yayitali ngakhale kuti chili ndi mphamvu zambiri.

06 Kuzindikira Malo: Ma Encoder Awiri a Magnetic ndi Magiya Amasintha Ma Angles Otembenukira Kamodzi Kukhala Mawerengedwe a Malo Otembenukira Kambiri

Pambuyo pochotsa PCBA, gulu la zida zazing'ono limatha kuwoneka kumbuyo. Izi si zida zazikulu zochepetsera, koma njira zothandizira zomwe zapangidwira kuzindikira ngodya.

 

Chithunzi 8: Malo olembera giya ndi maginito kumbuyo kwa bolodi lolamulira

 

Chithunzi 9: Kuzungulira kwa shaft yapakati kumayendetsa magiya awiri oyandikana nawo kuti azizungulira motsatizana.

Kapangidwe kake, kuzungulira kwa shaft yapakati kumayendetsa magiya awiri ang'onoang'ono. Gawo la maginito limayikidwa pakati pa giya iliyonse yaying'ono, ndi ma IC olembera maginito omwe amayikidwa pamalo ofanana kumbuyo kwa PCBA. Ma encoder a maginito amayesa kusiyana kwa maginito, kuchotsa kufunikira kwa ma disc optical grating. Amalekerera kuipitsidwa pang'ono kwa mafuta ndi fumbi, zomwe zimapangitsa kuti zikhale zoyenera kwambiri pa malo olumikizirana a robot otsekedwa bwino.

 

Chithunzi 10: Kapangidwe ka magiya awiri ndi ma encoder awiri kamawongolera mawonekedwe a angular ndipo kamathandiza kuzindikira malo ozungulira nthawi zambiri.

Chomwe chimadziwika kwambiri apa ndi kasinthidwe ka "dual-giar + dual magnetic encoder". Mtengo wake umapitirira kungowonjezera sensa yachiwiri kuti ikhale yolondola kwambiri; mwina imapangidwa kuti ikwaniritse njira yolumikizira malo ambiri:

Chojambulira chimodzi cha maginito chimayesa molondola ma angles mkati mwa 0–360°;

komabe cholumikizira chingazungulire maulendo angapo, ndipo cholembera chimodzi chokha sichingathe kudziwa kuchuluka kwa maulendo;

Ngati magiya awiriwa ali ndi kuchuluka kwa mano kapena magiya osiyanasiyana, amapanga mgwirizano wofanana ndi wa vernier;

Mwa kuphatikiza ma readings awiri a angular, wolamulira amawerengera malo enieni pamtundu waukulu kwambiri.

Kapangidwe kameneka kamapereka phindu lalikulu kwa ma robot okhala ngati munthu. Pambuyo pozimitsa, miyendo, manja kapena malo olumikizirana m'chiuno amatha kusunthidwa ndi mphamvu zakunja. Akangoyimitsidwanso, malo olumikizirana omwe amafuna kuyenda kwakukulu kwa homing amakhala ndi vuto lochepa ndipo amakhala pachiwopsezo chachitetezo. Kuzindikira malo olumikizirana nthawi zambiri kumalola malo olumikizirana kuti atenge deta ya malo olumikizirana nthawi yomweyo mphamvu ikangobwezeretsedwa.