Sarrafa sigina: Tace, Samfurin Samfuri da Binciken Mita

Riba:

• Ikon ginawa daidai da amfani da samfur, Nyquist da ra'ayoyi tare da tallafin AI
• Ikon fassara FFT, ƙirar tacewa da matakan taga zuwa daftarin lamba da lissafi tare da AI
• Ikon tabbatar da sakamakon sarrafa siginar da AI ke samarwa tare da siginar tunani, sarrafa naúrar da aunawa

Sarrafa sigina ita ce zuciyar injiniyoyin lantarki da sadarwa: fasahar ɗaukar igiyar wutar lantarki, rikodin sauti, karatun firikwensin, ko siginar rediyo da zazzage bayanan da ke cikinsa, tsaftace hayaniya, da canza shi. A cikin wannan rukunin, zaku ga yadda ake amfani da AI don koyon dabarun sarrafa sigina, gina matattara da lissafin canji, da yin bincike tare da lambar Python. Amma gargadi daga farkon: ƙaramin kuskuren ra'ayi a cikin sarrafa sigina (kuskuren mitar samfur, tsallake taga, naúrar tsoma baki) gaba ɗaya kuma cikin shiru za ta gurbata sakamakon; Har yanzu jadawali yana da kyau, amma ba daidai ba ne. Wannan shine dalilin da ya sa yana da mahimmanci don gwada kowane sakamako da AI ke samarwa akan siginar da aka sani da kuma sarrafa naúrar.

Samfura da Nyquist: inda duk ya fara

Don sarrafa siginar analog (ci gaba da wave) a cikin kwamfuta, muna auna ta a wasu tazara kuma mu canza ta zuwa lamba; Ana kiran wannan samfurin. Shi ne mitar samfur (fs, naúrar Hz) samfuran nawa muke ɗauka a cikin daƙiƙa guda. Ma'aunin Nyquist ya bayyana cewa don dawo da sigina daidai, mitar samfurin dole ne ta kasance aƙalla sau biyu mafi girman mitar siginar. Idan wannan yanayin bai cika ba, ƙananan mitoci suna fara kama da ƙananan mitoci; Ana kiran wannan aliasing kuma bayanan sun lalace har abada saboda ba za ku iya bambanta tsakanin waɗannan yanayi biyu ba.

AI yayi bayanin wannan ra'ayi sosai kuma yana iya nuna shi tare da misalai. Amma za ku yanke shawara lokacin zabar mitar samfurin ku: menene ainihin bandwidth na siginar ku, kuna da matattarar analog ɗin anti-aliasing, menene saurin ADC ɗin ku (Analog-Digital Converter: guntu mai canza siginar analog zuwa lamba) a zahiri yana aiki. AI na iya “ba da shawarar” mitar samfur, amma wannan shawarar zato ce ba tare da auna ainihin siginar ku ba.

Tukwici: Lokacin tambayar AI ta samfurin samfur, ƙayyade mafi girman mita da bandwidth na siginar ku da kanku. "Idan mafi girman ɓangaren sigina na shine ~ 4 kHz, ta yaya zan zaɓi fs kuma a ina zan sa matatar anti-aliasing?" kamar. Kada ku sanya AI ta yi la'akari da bakan; auna.

FFT da nazarin mita

FFT (Fast Fourier Transform) algorithm ne mai sauri wanda ke juyar da sigina daga axis na lokaci zuwa axis. Don haka "waɗanne mitoci ne a cikin wannan siginar kuma tare da nawa iko?" ya amsa tambayar. AI yayi kyau sosai yadda ake aiwatar da FFT, fassara sakamako, da rubuta lambar Python (numpy/scipy). Amma akwai kurakurai na gama gari a cikin FFT, kuma lambar AI na iya haɗawa da su cikin shiru:

• Matsakaicin mitar axis: Matsakaicin mitar fitarwa na FFT ya dogara da mitar samfur. Idan fs an shigar da shi ba daidai ba, duk mitoci suna fitowa ba daidai ba, amma jadawali ya bayyana al'ada.
• Windowing: Lokacin da aka karɓi siginar iyaka, katsewa yana faruwa a gefuna kuma ana ganin yaɗuwar ɓarna (yayi na gani) a cikin bakan. Windows kamar Hann da Hamming sun rage wannan. Idan lambar AI ta tsallake taga, sakamakon zai zama yaudara.
• Daidaita girman girman: Ana buƙatar sikeli da gyaran taga don canza girman fitarwar FFT zuwa ainihin ƙimar jiki. Idan an tsallake, amplitudes zai zama kuskure.

tace zane

Tacewa shine kewayawa ko algorithm wanda ke fitar da mitoci maras so daga sigina. Akwai nau'ikan asali guda huɗu: ƙananan wucewa (wucewa ƙananan mitoci), babban wucewa, band-pass, da band-pass (notch). Akwai manyan iyalai guda biyu na masu tacewa na dijital: FIR (madaidaicin amsawar motsa jiki, tsayayyen lokaci da layin layi) da IIR (amsar ƙwazo mara iyaka, babban canji tare da ƙarancin lissafi amma kwanciyar hankali da haɗarin lokaci).

AI yayi bayanin matakan ƙira na tacewa (mitar yankewa, fasfo ɗin wucewa, tsagewar bandeji, zaɓin oda) kuma yana rubuta lambar ƙira mai ƙima tare da scipy. Amma mitar yanke tacewar da kuka zana an ba da ita ta al'ada (dangane da mitar Nyquist), kuma shigar da fs kuskure anan kuskure ne na kowa. Bugu da ƙari, kwanciyar hankali da ɓarnar lokaci na iya zama matsala a cikin matatun IIR, kuma latency na iya zama matsala a cikin tsarin lokaci na ainihi. Tabbatar tabbatar da tacewar AI tare da jadawali na amsa mitar da sanannen siginar gwaji.

uku mini lokuta

Case 1 - Haɓaka rawar jiki. Wani injiniya yana yin samfurin girgizar mota a 1 kHz kuma yana ganin tsayi mai ƙarfi a cikin FFT a 300 Hz. Wannan kololuwa, wanda bai dace da ƙirar injin ba, yana da ruɗani. A zahiri akwai ainihin ɓangaren injin a kusa da 1300 Hz; Samfurin 1 kHz bai wadatar ba don wannan (Nyquist 500 Hz) kuma 1300 Hz ya mamaye 300 Hz. Bayan tattaunawa tare da AI "ko wannan kololuwa na gaske ne ko aliasing" da haɓaka mitar samfur zuwa 5 kHz, kololuwar ta bayyana a daidai wurin a 1300 Hz. Darasi: a kan tudu mai tambaya, tambaya ta farko ta samar da wadataccen abu.

Case 2 - Taga da aka tsallake. Wani ma'aikaci yana buƙatar lambar FFT daga AI kuma yana aiwatar da shi. Yana tsammanin sautin gwajin mitoci guda ɗaya amma yana ganin yaduwa a cikin bakan. Matsalar ita ce lambar ba ta yin taga (leakage na gani). Faɗa wa AI "ƙara taga Hann kuma a yi amfani da gyaran girman girman" kuma abin da aka fitar ya dawo kan kololuwar da ake sa ran. Darasi: Gwada lambar FFT tare da sanannen siginar mitoci ɗaya; Duba taga idan akwai zubewa.

Harka 3 - Ba daidai ba fs. Injiniya yana nazarin bayanan daga mai rikodin. Na'urar da aka yi rikodin a 48 kHz, amma an shigar da tsoho 44.1 kHz a cikin lambar AI. Ana canza duk mitoci da 8%; Sautin 1000 Hz yana bayyana a 1088 Hz. Ana samun kuskure lokacin duba ainihin fs na kayan aunawa. Darasi: mitar samfur shine lamba ɗaya mafi mahimmanci a cikin sarkar bincike; dole ne a tabbatar daga tushe.

Samfuran gaggawar da za a iya kwafi

FFT SETUP TEMPLATE"Rubuta lambar bincike ta FFT a Python (numpy/scipy). Input: samplingfrequency fs=[darajar] Hz, siginar siginar 'x'. Bari lambar tayi HAKAN: (1) Aiwatar da taga Hann, (2) Sami FFT, (3) daidai girman girman girman taga tare da fs-gefe. na lambar "Don Allah a bayyana a cikin layin sharhi wanda tunanin da kuke yi don in tabbatar da shi."

Samfurin SAMUN SARAUTA "Mafi girman mahimmin mitar sigina ta kusan [X] Hz. Yi bayanin gefen Nyquist, buƙatar tacewa mai hanawa, da madaidaicin gefen aminci lokacin zabar mitar samfur. Ba da shawarar kewayo amma jaddada cewa ya kamata in tabbatar da wannan ta hanyar auna ainihin bakan siginar."

FILTER DESIGN TEMPLATE "Shirya wani [low / high / band] wucewa dijital tace tare da scipy. Cutoff mita [X] Hz, Samfur mita fs = [Y] Hz. Kwatanta FIR da IIR zažužžukan (kwanciyar hankali, lokaci, jinkiri, lissafin lissafi). Nuna a fili a cikin lambar yadda aka daidaita mitar yankewa zuwa fs. Har ila yau, haɗa da madaidaicin mitar.

SAKAMAKO TAMBAYA "Bincika lambar sarrafa siginar da ke ƙasa da tuta tushen kurakuran shiru: fs kuskure, tsallake taga taga, naúrar crosstalk (Hz/kHz, V/mV), rashin daidaitawa, juzu'i guda/gefe biyu. Bayar da shawarar yadda zan gwada (tare da wace siginar magana) ga kowane. Code: [manna]."

Rauni mai ƙarfi / Ƙarfi mai ƙarfi

RAUNI GASKIYA: "Nemo mitar wannan siginar."

KARFIN KYAUTA: "Ina da siginar sigina tare da mitar samfurin 10 kHz. Rubuta lambar Python wanda ke gano manyan abubuwan mitar mita tare da FFT; yi amfani da taga Hann da gyaran amplitude, ma'auni na mitar mita bisa ga fs. A ƙarshen lambar, ƙara ingantaccen block tare da siginar gwajin gwaji na 1 kHz fs kuma duba idan scaling daidai ne. "

Rarraunan hanzari yana haifar da amsa maras kyau kuma yana ɗaukar fs; Yana dawo da sigogi masu ƙarfi da sauri kuma yana faɗakarwa don toshe gwajin tabbatar da kai.

Tebur na raka'a da zato a cikin sarrafa sigina

ra'ayi

kuskure akai-akai

tabbatarwa

Mitar samfur (fs)

Default maimakon ainihin FS na na'urar

Tabbatarwa daga saitin rikodi

mitar axis

Idan fs yayi kuskure gabaɗayan axis yana canzawa

Sautin gwajin mitar da aka sani

Windowing

Zuciyar Spectral lokacin da aka tsallake shi

Mafi girman nisa a siginar monotone

Girma

Daidaitawa/gyara bace

Kwatanta da sanannen siginar girma

tace yanke

daidaita kuskure bisa ga fs

Jadawalin amsa maimaitawa

Tsanaki: Kawai saboda jadawali na FFT ya yi kama da santsi kuma abin gaskatawa ba yana nufin daidai ba ne. Idan an daidaita axis ɗin mitar ba daidai ba, duk kololuwar suna a wurin da bai dace ba amma jadawali ya yi kama da kamala. Koyaushe daidaita tare da sanannen tunani.

Kuskuren gama gari

• Rashin tabbatar da mitar samfur daga tushen. Fs kuskure yana canza duk mitoci.
• Cin zarafin Nyquist da rashin lura da laƙabi. A kan tsaunukan da ake tuhuma, fara tambayar cancantar samfurin.
• Tsallake taga a cikin FFT. Yabo na Spectral yayi kama da kololuwar gaske.
• Mantawa da daidaita girman girman. Girman girma ya kasance marasa ƙima zuwa ƙimar jiki.
• Daidaita mitar yanke tace tace zuwa fs. Tace ta yanke a wani wuri daban fiye da yadda ake tsammani.

a takaice

A cikin wannan rukunin, kun sanya AI a matsayin taimako mai ƙarfi don koyan dabarun sarrafa siginar, rubuta FFT da lambar tacewa, da gina bincike. Amma a cikin sarrafa sigina, sakamakon na iya zama shiru shiru: mitar samfurin kuskure, tsallake taga, tsangwama ƙarar, ko rashin daidaitawa yana sa hoton yayi kyau amma kuskure. Don haka gwada kowane lambar da AI ta ke samarwa akan siginar da aka sani, tabbatar da mitar samfur daga tushen, kuma gwada kowane sakamako don naúrar da ƙwarewar jiki. Bincika manufar Nyquist da aliasing a farkon kowane bincike.

Aikin aikace-aikace

Ƙirƙirar siginar gwajin roba a Python: jimlar mitoci biyu da aka sani (misali 1 kHz da 3 kHz), fs=10 kHz. Nemi lambar bincike daga AI tare da samfurin "FFT saitin" kuma tabbatar da cewa kololuwar suna bayyana a daidai mitoci. Sannan shigar da fs da gangan ba daidai ba (misali 8 kHz) kuma lura da yadda kololuwar ke motsawa. A ƙarshe, cire taga kuma ga yabo na gani. Rubuta sakamakon kowane gwaji a cikin jumla ɗaya.

jerin abubuwan dubawa

• [ ] Na tabbatar da mitar samfur (fs) daga ainihin saitin mai rikodin.
• [ ] Na duba ma'auni na Nyquist kuma na kimanta haɗarin haɗakarwa.
• [ ] Na duba cewa ana aiwatar da gyaran taga da girman girman a cikin lambar FFT.
• [ ] Na gwada lambar tare da siginar tunani na sanannen mita.
• [ ] Na tabbatar ta hanyar mayar da martani na gani cewa an daidaita mitar yanke tacewa daidai zuwa fs.
• [ ] Na sanya duk raka'a (Hz/kHz, V/mV) daidai.