Ịmalite na RFID

Usoro UHF RFID nwere akụkụ atọ: onye na-agụ akwụkwọ, antenna ma ọ bụ karịa, na tags. Onye na-agụ akwụkwọ na-emepụta mgbaàmà redio 920–925 MHz ma na-eziga ya site na antenna. Mgbe tag na-adịghị arụ ọrụ banyere n'ime ubi antenna, ọ na-anakọta ike site na ebili mmiri redio iji nye obere microchip ya ike (na-achọkarị naanị ~10 microwatts). Chip ahụ na-agbanwe mgbaàmà na-abata wee gbasaa ya azụ. n'ụzọ bụ isi na-egosipụta ụdị agbanweela azụ. Mgbaàmà a na-egosipụta na-ebu koodu ngwaahịa eletrọnịkị pụrụ iche (EPC) nke tag.

Usoro ịgụ niile. site na ịnyefe ajụjụ ruo ịnata nzaghachi tag. na-ewe ihe dịka 1–3 milliseconds. Nke a bụ ihe na-eme ka otu onye na-agụ akwụkwọ nwee ike ịdepụta 200+ tags kwa sekọnd na-eji usoro mgbochi mgbochi EPC Gen2. Mfu mgbaàmà gburugburu bụ ihe dị mkpa (-40 ruo -80 dB), nke mere na ike TX onye na-agụ akwụkwọ (na-abụkarị 30 dBm / 1 watt) na mmetụta chip tag (ruo -22 dBm) bụ nkọwa dị oke mkpa.

RFID na-agbasa n'ọtụtụ ụdị ugboro, mana UHF (860–960 MHz) na-achịkwa ngwa azụmahịa n'ihi na ọ na-enye ezigbo nguzozi nke oke ịgụ, ọsọ, na ọnụ ahịa tag. LF (125 kHz) na-agụ n'ime 10cm na ~1 tag/sec. dị mma maka nyocha anụmanụ mana ọ dị ngwa maka ngwa ngwa. HF/NFC (13.56 MHz) ruru ~1m na ~50 tags/sec. dị mma maka ịkwụ ụgwọ na kaadị nnweta. UHF ruru 1–12+ mita na 200+ tags/sec. dị mma maka yinye ọkọnọ, ire ere, na nyocha akụ.

N'ime Vietnam 920–925 MHz band, ndị na-agụ akwụkwọ na-eji Frequency Hopping Spread Spectrum (FHSS) n'ofe ọtụtụ ọwa. Usoro a bụ: ugboro = 920.0 + (channel_index × 0.5) MHz. Nhazi nkịtị na-eji ọwa 6 [0, 2, 4, 6, 8, 10] na-agbasa 920.0 ruo 925.0 MHz maka nkewa ọwa kachasị.

Channel Index → Frequency (MHz)   Formula: f = 920.0 + (idx × 0.5)

Ch 0  → 920.0    Ch 4  → 922.0    Ch 8  → 924.0
Ch 1  → 920.5    Ch 5  → 922.5    Ch 9  → 924.5
Ch 2  → 921.0    Ch 6  → 923.0    Ch 10 → 925.0
Ch 3  → 921.5    Ch 7  → 923.5

Typical: use [0, 2, 4, 6, 8, 10] for max channel separation

Tag UHF RFID ọ bụla nwere akụkụ abụọ dị mkpa: ụkpụrụ antenna (etched ma ọ bụ ebipụtara aluminom na ihe ndabere PET) na microchip (IC). Antenna na-ejide mgbaàmà onye na-agụ akwụkwọ na chip na-ahazi iwu ma na-eweghachi data. Mmetụta chip bụ ike kacha nta chip chọrọ iji rụọ ọrụ. chip nke nwere ọkwa -22.1 dBm nwere ike iteta na naanị ~6.3 microwatts. Obere (ihe na-adịghị mma) = mmetụta ka mma = ogologo oke ịgụ.

Ezinụlọ chip nkịtị gụnyere: NXP UCODE 9 (-22.1 dBm, 128-bit EPC, enweghị ebe nchekwa onye ọrụ. na-achịkwa na ire ere), Impinj M700 series (-22.1 dBm, 128-bit EPC. siri ike na ngwa ngwa), na Quanray QStar-7U (-21.0 dBm, 128-bit EPC, 512-bit ebe nchekwa onye ọrụ. dị mma mgbe ịchọrọ ịchekwa data ozugbo na tag).

Ụdị ụdị tag: Dry Inlays (tag dị na PET, ¢3–8, maka ịgbanwe n'ime akara), Wet Inlays (nwere ihe nrapado, ¢5–12, dị njikere itinye), Sticker Labels (ebipụta, ¢8–25, nwere aha), Hard Tags ($1–15, siri ike maka gburugburu ebe obibi siri ike), na akara Woven/Fabric (¢15–40, akpọrọ n'ime uwe). Nextwaves na-emepụta inlays akọrọ site na 35×17mm ruo 95×8mm na akara sticker n'ogo dakọtara.

EPCglobal Gen2 (ISO 18000-6C) na-achịkwa otú ndị na-agụ UHF si na-ekwurịta okwu na akara. Ihe ọhụrụ bụ algọridim mgbochi mgbochi slotted-ALOHA nke na-enye otu onye na-agụ ihe ka ọ na-edepụta ọtụtụ narị akara n'otu oge na-enweghị ha na-egbochi ibe ha.

Nke a bụ otú okirikiri ndepụta si arụ ọrụ: Onye na-agụ ihe na-eziga Ajụjụ nwere paramita Q (na-emepụta oghere oge 2^Q). Akara ọ bụla na-ahọrọ oghere enweghị usoro wee chere. Mgbe oghere akara ruru, ọ na-aza nọmba enweghị usoro 16-bit. Ọ bụrụ na otu akara na-aza, onye na-agụ ihe ACKs ma nata EPC zuru oke. Ọ bụrụ na ọtụtụ akara na-emegiderịta, onye na-agụ ihe na-agafe oghere ahụ. Mgbe oghere niile gasịrị, a na-edozi Q. elu ma ọ bụrụ na ọtụtụ mgbochi, gbadaa ma ọ bụrụ na ọtụtụ oghere efu. na okirikiri na-emegharị.

Ntọala Q bara uru: Q=2 (oghere 4) maka akara 1–5, Q=4 (oghere 16) maka akara 5–20, Q=5 (oghere 32) maka akara 20–100, Q=6 (oghere 64) maka akara 100–500, Q=7 (oghere 128) maka akara 500+. Q dị elu pụtara obere mgbochi mana okirikiri ngwa ngwa.

Nkwụsi ike nke oge na-achịkwa ogologo oge akara na-echeta na a gụọlarị ya. Oge S0 na-eweghachi ozugbo (maka nlekota na-aga n'ihu). S1 na-adịgide 0.5–5 sekọnd (ndepụta ọkọlọtọ). S2/S3 na-adịgide ≥2 sekọnd (ọnụ ụzọ ọdụ ụgbọ mmiri na ihe njem ebe ịchọrọ ka agụọ akara ọ bụla otu ugboro kwa ngafe). Iwu mkpịsị aka: jiri S0 maka nlekota shelf, S2/S3 maka ọnụ ụzọ.

Tag Count → Q Value → Slots → Use Case

  1-5       Q=2       4       fast, low overhead
  5-20      Q=4       16      good balance
  20-100    Q=5       32      warehouse shelves
  100-500   Q=6       64      pallet scanning
  500+      Q=7       128     dock doors, bulk

Higher Q = fewer collisions but slower rounds

Tag Gen2 ọ bụla nwere ụlọ akụ ebe nchekwa 4. Edebere (Ụlọ akụ 00): Gbuo paswọọdụ + paswọọdụ nnweta, ngụkọta nke 64 bits. EPC (Ụlọ akụ 01): CRC-16 + Okwu njikwa Protocol + njirimara EPC gị, na-abụkarị 96–128 bits. TID (Ụlọ akụ 10): Factory-burned pụrụ iche chip ID nke a na-agaghị agbanwe. bara uru maka mgbochi aghụghọ. Onye ọrụ (Ụlọ akụ 11): Nhazi data omenala nhọrọ (0 ruo 512+ bits dabere na chip), bara uru maka nọmba batch, ụbọchị nyocha, ma ọ bụ data sensọ.

Mgbe onye na-agụ akwụkwọ na-edepụta tags, ọkwa ọ bụla nwere: njirimara antenna (ọdụ ụgbọ mmiri), uru RSSI raw (0–255, gbanwee na dBm site na: dBm = -100 + gburugburu (raw × 70 / 255)), data EPC (12+ bytes), na ndeksi ọwa ugboro. Data a bụ ihe ngwa gị na-ahazi iji mapu ịgụ tag anụ ahụ na mmemme azụmahịa dị ka 'ihe ebugara' ma ọ bụ 'pallet natara'.

[ANT] [RSSI] [EPC ×12 bytes ..................] [CH]
 01    B4     30 34 25 7B F7 19 4E 40 00 00 1A 85  06

Antenna:  1 (port 1)
RSSI:     180 → dBm = -100 + round((180×70)/255) = -51 dBm
EPC:      3034257BF7194E4000001A85 (SGTIN-96)
Channel:  6 → 920.0 + (6×0.5) = 923.0 MHz
GTIN-14:  80614141123458  Serial: 6789

Nke a bụ ndepụta bara uru maka ịtọ sistemụ RFID mbụ gị, yana nduzi kpọmkwem na usoro ọ bụla.

Input:  GTIN-14=08600000232451  Serial=1001  Prefix=7 digits
Output: 30 14 1A 80 0E 98 78 00 00 00 03 E9  (12 bytes)