KWARANGWAL NA WAJE NA ƘUGU DA YA KOYA A KAN JIKIN KWAMFUTA

Ana ƙera kwarangwal na waje masu amfani da wuta (powered exoskeletons) na ƙafafu duka don gyaran jiki bayan rauni (rehabilitation) da kuma taimaka wa mutane masu lafiya su yi tafiya. Na’urorin ƙugu suna da jan hankali musamman: tsokokin ƙugu suna yin babban kaso na aikin tabbatacce (positive work) na tafiya a kan ƙasa mai lebur, don haka taimaka musu zai iya sauƙaƙa wa tsokokin da ke yin yawancin aikin.

Matsalar ita ce mai sanya na’urar. Da zarar mota ta tura wani gaɓa (joint), salon tafiya yana canzawa kuma tsokoki suna sake tsara aikinsu. Mafita da aka saba, inganta “da ɗan adam a cikin zagayen” (human-in-the-loop optimisation), tana daidaita na’urar kai tsaye a kan kowane mutum — dogayen gwaje-gwaje da dole a maimaita su ga kowane sabon mai amfani da kowane yanayi.

Mai tafiya na kwamfuta a matsayin abokin horo

Yifei Yuan, Xianlian Zhou da abokan aikinsu a New Jersey Institute of Technology, tare da Kessler Foundation, sun mayar da horon cikin kwamfuta. Ɗan adam ɗinsu na kwamfuta (virtual human) yana da cikakken jiki da masu motsa tsoka 304 (muscle actuators) ke tafiyar da shi. Tsayinsa, nauyinsa, ƙarfin tsokarsa, takunsa da saurin tafiyarsa ana zaɓarsu ba bisa tsari ba (at random), daga kusan mita 1.55 da kilogram 54 har zuwa mita 1.94 da kilogram 97, ta yadda mai sarrafawar (controller) zai koya domin dukkan al’umma maimakon mutum ɗaya.

Wakilan koyo (learning agents) biyu suna tarayya a duniyar kwaikwayo ɗaya: ɗaya yana sarrafa jikin, ɗayan kuma kwarangwal na wajen. Da farko jikin yana koyon tafiya shi kaɗai; sannan a ɗaura na’urar kuma dukansu biyu su daidaita da juna. Kwarangwal na wajen yana ganin kusurwoyi da saurin ƙugu ne kawai, da jinkiri na millisecond 40 — abu mai sauƙi da ƙaramar kwamfutar Raspberry Pi 5 da na’urorin jin motsi (motion sensors) marasa tsada za su iya tafiyar da shi.

Ba da lada ga ƙoƙarin da ya dace

Me ya kamata na’urar ta yi nufi? Ana ba masu sarrafawa na baya lada (reward) don rage kunna tsoka (muscle activation) ko aikin inji (mechanical work), abubuwan da ke maye gurbin ƙoƙari. A nan, ladan kwarangwal na wajen ya haɗa da ƙarfin metabolism (metabolic power) na tsokokin ƙugu, wanda aka lissafa da samfurin ilimin aikin jiki (physiological model) na yadda tsoka ke amfani da makamashi.

Ƙungiyar ta horar da nau’i biyu. Ɗaya ya kuma ba motocin lada don isar da ƙarfin inji tabbatacce (positive mechanical power). Ɗayan, ba tare da wannan ƙarin sashe ba, ya fi kyau a kwaikwayo: makamashin da tsokokin ƙafa da aka bincika ke amfani da shi ya ragu da 13.8% idan aka kwatanta da tafiya ba tare da na’urar ba, a kan 8.8% ga nau’in da ke da sashen ƙarfin. Raguwa mafi girma ta kasance a tsokokin ƙugu: kusan 30%.

Masu tafiya takwas, babu daidaitawa

An loda nau’in da ya fi kyau, ba tare da canji ba, a kan ainihin kwarangwal na waje na ƙugu mai nauyin kilogram 5.94. Manya takwas masu lafiya, masu shekaru 18 zuwa 44, sun yi tafiya a kan injin tafiya a mita 1.25 a kowace daƙiƙa na kusan mintuna shida a kowane yanayi, yayin da na’urar nazari mai ɗaukuwa ke ɗaukar samfurin numfashinsu don auna iskar oxygen da suka yi amfani da ita da carbon dioxide da suka fitar.

• Sanya na’urar a kashe kawai ya ɗaga makamashin da tafiya ke ci da 13.1%.
• Da mai sarrafawar yana aiki, makamashin ya ragu da 18.3% idan aka kwatanta da na’urar a kashe — ga kowane ɗaya daga cikin mahalarta takwas, da 7.2% zuwa 27.7%.
• Idan aka kwatanta da tafiya ba tare da kowace na’ura ba, matsakaicin ragi ya kai 7.4%, wanda ya bambanta sosai tsakanin mutane takwas har bai bayyana a fili a ƙididdiga (statistically) ba. Shida daga cikin takwas sun yi tafiya da ƙarancin makamashi fiye da ba tare da na’urar ba, har zuwa 24.2%; biyu har yanzu sun kashe ɗan fiye.

A wata ma’ana, taimakon ya cire kusan watt 0.63 a kowane kilogram na nauyin jiki, kusan ninki ɗaya da rabi na 0.41 da ɗaukar na’urar ya ƙara.

Faɗaɗɗen motsi a ƙugu

Kewayon motsin ƙugun masu sanyawa ya ƙaru daga digiri 44 zuwa 60, kusan gaba ɗaya a lanƙwasa cinya zuwa gaba (flexion), yayin da yawan takunsu (cadence) da ƙyar ya canza. Taimakon ya zo a lokacin da ya dace: 98.5% na ƙarfin da motocin suka isar ya tura a hanya ɗaya da yadda ƙugun ke motsawa, ko da yake ba a taɓa ba nau’in da aka yi amfani da shi lada kai tsaye don haka ba. Ragin makamashinsa ya yi daidai da na mai sarrafawa na baya na ƙungiyar, wanda aka gwada a zama ɗaya a ƙarfin murɗawa (torque) iri ɗaya.

Na’ura mai sauƙin nauyi a gaba

Marubutan sun nuna na’urar kanta. Nauyinta ya kusan ninka na wasu biyu da aka horar a kwaikwayo (kilogram 3.2 da 2.9), kuma an tafiyar da ita a newton-mita 12, ƙasa da 18 da aka yi amfani da shi a horo, don ta kasance mai daɗin sanyawa. Firam mai sauƙin nauyi da ya fi dacewa da jiki, manyan rukunan masu tafiya, wasu sauri da gangare, da mutane masu matsalar tafiya su ne gwaje-gwaje na gaba.