Amasistimu okushayela e-Mecanum (drivetrains) aphuma emzileni ngesikhathi sezinqubo ezizimele ze-FTC autonomous ngoba ukunyakaza kwawo kuncike ekuhlangabezaneni nasekuqedaneni okunembile ngokwezibalo kwamandla e-vector ane-engeli engu-45 degrees. Kumathayela e-foam e-EVA athambile nanganabile, amandla angalingani kanye nokushelela kwamarola kuvimbela lawo mandla ukuba alingane ngokuphelele, okudala ukujikeleza okungafuneki (yaw) okwanda njengoba ibanga liqhubeka. Awudingi ama-pod e-odometry angaxhunyiwe emandleni abizayo (dead wheels) ukulungisa lokhu: ungaqeda iningi lamaphutha endlela ye-autonomous ngokuvala i-loop yesiqondiso usebenzisa i-IMU eyakhelwe ngaphakathi ku-REV Control Hub kanye nokunciphisa ukusheshisa ukuze kuhlale ngaphakathi kwemingcele yokungqubuzana (friction) yamarola akho.

Isayensi Yokusebenza Kokushelela kwe-Mecanum

Isondo elijwayelekile lokudonsa lifaka amandla ahambisana nokuphenduka kwesondo. Isondo le-Mecanum lidlulisela amandla ngamarola angasebenzi (passive rollers) abekwe nge-engeli engu-45 degrees uma kuqhathaniswa nepuleti lesondo. Lapho injini iphendulela isondo le-Mecanum phambili, indawo ethintana nephansi idala i-vector enqamulelayo: ingxenye eyodwa idudulela irobhothi phambili, kanti ingxenye elinganayo ehlangothini idudulela eceleni.

Ukuze lihambe liqonde ngqo phambili, amasondo angakwesokunxele nangesokudla afaka amandla ahlangothini alinganayo aphikisanayo aqedanayo, okushiya kuphela amandla okuqhubekela phambili. Ukuze lihambe eceleni kuphela (strafe), amapheya anqamulelayo aphikisanayo aphendukelana, aqede amandla okuya phambili bese ehlanganisa amandla okuya eceleni.

Lokhu kuqedana kwamandla e-vector kucabanga ukuthi kunezimo ezintathu ezikhona, ezingalokothi zibe yiqiniso enkundleni yomncintiswano:

• Amandla ajwayelekile alinganayo (Symmetric normal forces): Uma isisindo esiphakathi nerobhothi lakho (centre of mass) sitshekele ngisho kancane ebhethrini noma endleleni yokuphakamisa, amakhona asinda kakhulu athola amandla amakhulu kanye nokubamba okuqinile. Amakhona alula ayashelela, okwenza amandla asemaceleni angapheli.
• Ukubamba okufanayo kwendawo: Amathayela athambile axhumanayo e-foam e-EVA ayakhubazeka ngaphansi kwesisindo. Amarola ashona phansi e-foam ngamazinga angafani, ashintshe i-engeli yokuthinta kanye nokuvinjwa kokuginqika (rolling resistance) njalo ngomzuzwana.
• Ukungqubuzana kokunyakaza okufanayo (Identical kinetic friction): Amarola epulasitiki neraba angasebenzi kumasondo ajwayelekile e-Mecanum anomehluko omncane ekwenziweni kwawo, ukunyakaza kwe-eksali, kanye nokungafani kokungqubuzana kwangaphakathi.

Lapho amandla e-vector ehluleka ukuqedana ngokuphelele, umphumela osheshayo uba amandla okujikeleza (yaw torque) angalawulwa. Uma irobhothi lakho seliphenduke ngama-degree amabili noma amathathu nje kuphela lisuka esiqondisweni elalihloselwe kuso, konke ukubala kwe-encoder yenjini okulandelayo kuqhuba irobhothi endleleni ephendukile, okwandisa iphutha lendawo ngokuhamba kwesikhathi.

Isixazululo: Ukulungisa Isiqondiso Nge-IMU Esebenzayo

Yize ama-encoder enjini ekala ukuthi izingxenyana zamasondo ziphenduke kangakanani, awakwazi ukukala ukushelela kwamarola phansi. Nokho, awudingi ukulandelela indawo ye-Cartesian ngokuphelele ukuze uxazulule iningi lokungabi nembobo kwe-autonomous. Uma uvimbela irobhothi ukuba lingajikelezi lisuke esiqondisweni elalihloselwe kuso, amaphutha okuhamba e-encoder ahlala eqondile futhi ebonakala kalula esikhundleni sokuba ngokujikeleza nokumosha konke.

I-REV Control Hub ngayinye inophiko lwangaphakathi lokukala ukunyakaza (Inertial Measurement Unit - IMU) olukwazi ukufunda ukuma kwe-engeli (yaw) ngokunemba okuphezulu kanye nokuphuma kancane emzileni phakathi nesikhathi se-autonomous semizuzwana engu-30.

Ukusungula i-Loop Yokukhiya Isiqondiso

Esikhundleni sokuthumela amandla ajwayelekile ngqo ezinjinini zakho zokushayela, dlulisa iphutha lakho lesiqondiso nge-loop yokulawula ye-Proportional-Derivative (PD) efaka amandla okulungisa ukujikeleza kuzibalo ze-kinematic ze-Mecanum ngesikhathi sangempela.

Izibalo ezijwayelekile ze-kinematic ze-Mecanum zamandla enjini yilezi:

• Front Left = Drive + Strafe + Turn
• Front Right = Drive - Strafe - Turn
• Back Left = Drive - Strafe + Turn
• Back Right = Drive + Strafe - Turn

Enqubweni ye-open-loop, i-Turn isethwa ku-ziro ngesikhathi sokushayela phambili noma ukuhamba eceleni. Enqubweni esebenzayo ekhiye isiqondiso, i-Turn ibalwa ngendlela eguqukayo kusuka kumpendulo ye-yaw ye-IMU kuyo yonke i-iteration ye-loop:

1. Funda isiqondiso samanje: Thola i-engeli ye-yaw yamanje kusuka ku-IMU.
2. Bala iphutha lesiqondiso: Bala umehluko omfushane we-engeli phakathi kwesiqondiso osihlosile nesiqondiso samanje, uqinisekise ukuthi ulinganisa i-engeli phakathi kuka -180 no +180 degrees (noma -π no +π radians) ukuvimbela amaphutha okuzungeza (wrap-around).
3. Bala ukulungisa: Phindaphinda iphutha nge-proportional gain elungisiwe (kP), bese wengeza izinga lokushintsha kwephutha eliphindaphindwe nge-derivative gain (kD) ukunciphisa ukuxhaxhaza (oscillations).
4. Sebenzisa futhi ulinganise (normalize): Faka leli nani lokulungisa kokuguqukayo kwe-Turn. Uma kukhona ukubalwa kwenjini okweqa amandla angu-1.0 (noma -1.0), hlukanisa wonke amandla ezinjini ezine ngenani eliphakeme kakhulu eliphelele (maximum absolute value) ukuze ugcine izilinganiso ze-vector ezihlosiwe ngaphandle kokunqunywa (clipping).

Ukulinganisa amandla enjini kubaluleke kakhulu. Uma irobhothi lakho lihamba phambili ngamandla agcwele kanti isilawuli sidinga ukulungiswa kokujika, ukunqunywa okungalinganisiwe kuzoqeda umehluko wokulungisa bese kuvumela irobhothi ukuba liphume emzileni kungakhathaliseki ukuthi izilungiselelo zesofthiwe yakho zithini.

Ukulawula Ukushelela Kokunyakaza Ngokunciphisa i-Slew Rate

Ukulungiswa kwesiqondiso okusebenzayo kubhekana nokuphuma emzileni kokujikeleza, kodwa ukusheshisa okusheshayo kubangela ukushelela okuya phambili nasemaceleni lapho amasondo ephenduka ngokushesha kunokusheshisa kwe-chassis. Lapho amarola elahlekelwa ukubamba phansi ku-foam, ama-encoder enjini aqopha ibanga elingazange lihanjwe.

Ukulungisa ukushelela kokunyakaza ngaphandle kwama-dead wheel:

• Nciphisa Ukusheshisa (Slew Rate): Ungalokothi ugxumele amandla ahlosiwe enjini kusuka ku-0.0 kuya ku-1.0 emzuliswaneni owodwa we-loop. Khulisa amandla kancane kancane usebenzisa isilinganiso esilula sokulinganisela (isib., ukumisa ukusheshisa ekwandeni okungengaphezulu kwamandla angu-0.05 ngomjikelezo wemizuzwana engu-20).
• Yehlisa Isivinini nge-Profile: Sebenzisa ukuhlelwa kwesivinini se-trapezoidal noma se-S-curve ukwehlisa isivinini serobhothi ngaphambi kokufinyelela isibalo se-encoder esihlosiwe. Ukubhuleka ngokushesha kubangela ukuthi irobhothi lishelele phezu kwamathayela, okonakalisa indawo yakho yokuma ehlosiwe.
• Ukuthintana Kwezinsimbi Naphansi: Qinisekisa ukuthi i-chassis ye-drivetrain yakho inokugoba okuncane (torsional compliance) noma ukumiswa kwe-rocker (rocker suspension) ku-eksali eyodwa. Uma i-chassis eqinile enamasondo amane ihlangana nomthungo ongalingani phakathi kwamathayela e-foam, isondo elilodwa liyaphakama kancane phansi, lilahlekelwe ukubamba ngokushesha bese lidala ukushelela.

Kudingeka Nini Ngempela Ama-Dead Wheel?

Amaqembu avame ukugxumela kuma-pod e-odometry anamasondo amathathu aneziphethu ngoba ekholelwa ukuthi amasondo e-Mecanum awakwazi ukushayela indlela ethembekile yemizuzwana engu-30 ye-autonomous. Eqinisweni, i-loop yokukhiya isiqondiso elungiswe kahle ehambisana nokulawula isivinini ngama-encoder yanele ukufeza imisebenzi ebalulekile ye-autonomous, ukuziqondanisa ngokuthembekile nezindonga zenkundla, nokupaka ngendlela engaguquki.

I-odometry yama-dead wheel idingeka kuphela lapho isu lakho le-autonomous lidinga izindlela eziyinkimbinkimbi, ezinesivinini esiphezulu ze-spline ezinamaphuzu amaningi (njengezindlela ezigcwele ze-Road Runner noma ze-Pedro Pathing) lapho irobhothi kufanele lazi izixhumanisi zalo ezinembile ze-(X, Y) ngemuva kokungqubuzana nezinto zomdlalo noma ukuhamba ngamandla eceleni kuyo yonke inkundla.

Uma wakha futhi ulungisa amasistimu okushayela e-FTC noma ufuna ukuba yingcweti ekulawuleni ukunyakaza kwe-autonomous neqembu lakho, hlola imihlahlandlela yethu yobunjiniyela bomncintiswano ku-Sheen Robotics FTC Resources.