{"id":20497,"date":"2023-12-14T10:15:00","date_gmt":"2023-12-14T09:15:00","guid":{"rendered":"https:\/\/www.md-elektronik.com\/?p=20497"},"modified":"2023-12-14T10:15:00","modified_gmt":"2023-12-14T09:15:00","slug":"radar","status":"publish","type":"post","link":"https:\/\/www.md-elektronik.com\/cs\/radar\/","title":{"rendered":"Radar"},"content":{"rendered":"\n

RADAR =<\/strong> Ra<\/strong>dio D<\/strong>etection a<\/strong>nd R<\/strong>anging<\/p>\n

Radarov\u00fd modul \u2013 klasick\u00e1 senzorika<\/strong><\/h2>\n

Jedn\u00e1 se o aktivn\u00ed syst\u00e9m, kter\u00fd vys\u00edl\u00e1 a p\u0159ij\u00edm\u00e1 mikrovlny v p\u00e1smu GHz.
Tato technologie umo\u017e\u0148uje bezdotykovou detekci a lokalizaci jednoho nebo v\u00edce objekt\u016f pomoc\u00ed elektromagnetick\u00fdch vln.<\/p>\n

Radarov\u00e1 ant\u00e9na p\u0159i tom vys\u00edl\u00e1 sign\u00e1ly ve form\u011b radarov\u00fdch vln. Tyto vlny se \u0161\u00ed\u0159\u00ed rychlost\u00ed sv\u011btla a \u010dlov\u011bk je nevn\u00edm\u00e1. Pokud jedna z t\u011bchto vln naraz\u00ed na objekt, sign\u00e1l se zm\u011bn\u00ed a odraz\u00ed \u2013 m\u016f\u017eete si to p\u0159edstavit jako ozv\u011bnu. Ant\u00e9na v senzoru p\u0159ij\u00edm\u00e1 odra\u017een\u00fd sign\u00e1l a z\u00edsk\u00e1v\u00e1 tak informace o objektu. Vzd\u00e1lenost p\u0159edm\u011btu od vozidla lze nap\u0159\u00edklad ur\u010dit pomoc\u00ed doby chodu sign\u00e1lu. Ve druh\u00e9m kroku jsou nyn\u00ed do elektroniky vozidla p\u0159en\u00e1\u0161eny informace, kter\u00e9 maj\u00ed vyvolat reakci, nap\u0159\u00edklad \u201esn\u00ed\u017eit rychlost\u201c.<\/p>\n

Hlavn\u00ed v\u00fdhodou t\u00e9to technologie je, \u017ee nen\u00ed p\u0159\u00edli\u0161 citliv\u00e1 na tmu, vlhkost, ne\u010distoty ani teplotu. M\u00e1 ale i sv\u00e9 nev\u00fdhody. Pat\u0159\u00ed sem i takzvan\u00e9 interference radarov\u00fdch senzor\u016f. Jedn\u00e1 se o vz\u00e1jemn\u00e9 ru\u0161en\u00ed r\u016fzn\u00fdch radarov\u00fdch senzor\u016f, kter\u00e9 pracuj\u00ed ve stejn\u00e9m p\u0159id\u011blen\u00e9m frekven\u010dn\u00edm p\u00e1smu. Pokud se zorn\u00e9 pole sn\u00edma\u010d\u016f p\u0159ekr\u00fdv\u00e1, doch\u00e1z\u00ed k ru\u0161en\u00ed neboli interferenci.
Na n\u00e1prav\u011b tohoto probl\u00e9mu se v\u0161ak ji\u017e pracuje.<\/p>\n

Radarov\u00e9 senzory \u2013 rozd\u00edly a oblasti pou\u017eit\u00ed<\/strong><\/h2>\n

Obecn\u011b se ve vozidle rozli\u0161uj\u00ed t\u0159i r\u016fzn\u00e9 dosahy radaru:<\/p>\n

    \n
  • LRR<\/strong> Long Range Radar\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u00a0\u00a0\u00a0\u00a0\u00a0 > 160 m<\/li>\n
  • MRR<\/strong> Mid Range Radar\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 160 m<\/li>\n
  • SRR<\/strong> Short Range Radar\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u00a0\u00a0 50 m<\/li>\n<\/ul>\n

    Senzory pou\u017e\u00edvaj\u00ed frekvence 24, 77 a 79 GHz.<\/p>\n

    P\u0159edn\u00ed \u010d\u00e1st (24 \/ 77 GHz)<\/strong><\/p>\n

    V p\u0159edn\u00ed \u010d\u00e1sti vozidla jsou instalov\u00e1ny senzory pro LRR a SRR \/ MRR.
    Pou\u017e\u00edvaj\u00ed se jako asisten\u010dn\u00ed syst\u00e9my pro \u0159\u00edzen\u00ed, jako druh\u00fd p\u00e1r o\u010d\u00ed, kter\u00e9 podporuj\u00ed \u0159idi\u010de. Shroma\u017e\u010fuj\u00ed data o doprav\u011b p\u0159ed v\u00e1mi.<\/p>\n

    Hlavn\u00edmi krit\u00e9rii, kter\u00e1 se zde m\u011b\u0159\u00ed, jsou vzd\u00e1lenost a rychlost.
    Asisten\u010dn\u00ed syst\u00e9m ve vozidle tak m\u016f\u017ee samostatn\u011b udr\u017eovat minim\u00e1ln\u00ed vzd\u00e1lenost od vozidla jedouc\u00edho vp\u0159edu a v p\u0159\u00edpad\u011b pot\u0159eby zah\u00e1jit nouzov\u00e9 brzd\u011bn\u00ed, aby zabr\u00e1nil nehod\u011b.<\/p>\n

    Zadn\u00ed \u010d\u00e1st (24 \/ 77 GHz)<\/strong><\/p>\n

    V zadn\u00ed \u010d\u00e1sti vozidla monitoruj\u00ed senzory prostor za vozidlem.
    Vzhledem k tomu, \u017ee \u0159idi\u010d se obvykle soust\u0159ed\u00ed na prostor p\u0159ed sebou a situaci za sebou m\u016f\u017ee zaznamenat pouze kr\u00e1tk\u00fdm pohledem do zp\u011btn\u00e9ho zrc\u00e1tka, jsou radarov\u00e9 senzory v tomto p\u0159\u00edpad\u011b velmi \u00fa\u010dinnou podporou.
    V p\u0159\u00edpad\u011b p\u0159edj\u00ed\u017ed\u011bc\u00edho man\u00e9vru nebo zm\u011bny j\u00edzdn\u00edho pruhu m\u016f\u017ee b\u00fdt \u0159idi\u010d varov\u00e1n vizu\u00e1ln\u00edm nebo akustick\u00fdm sign\u00e1lem, pokud se zezadu rychle bl\u00ed\u017e\u00ed jin\u00e9 vozidlo. Pat\u0159\u00ed sem tak\u00e9 \u201ehl\u00edd\u00e1n\u00ed mrtv\u00e9ho \u00fahlu\u201c.<\/p>\n

    Okol\u00ed \u2013 360\u00b0 (77 \/ 79 GHz)<\/strong><\/p>\n

    Kombinace r\u016fzn\u00fdch radarov\u00fdch senzor\u016f um\u00edst\u011bn\u00fdch kolem vozu poskytuje 360\u00b0 pohled do v\u0161ech stran.
    To je mo\u017en\u00e9 jak na kr\u00e1tkou vzd\u00e1lenost, aby \u0159idi\u010d l\u00e9pe vid\u011bl nejasn\u00e9 situace, tak na st\u0159edn\u00ed a dlouhou vzd\u00e1lenost pro autonomn\u00ed j\u00edzdu.<\/p>\n

    Kombinace 8 radarov\u00fdch syst\u00e9m\u016f poskytuje spolehliv\u00fd p\u0159ehled ve v\u0161ech sm\u011brech.<\/p>\n

    Radarov\u00e9 senzory \u2013 1D a\u017e 4D<\/strong><\/p>\n

    1D \u2013 Radar<\/strong> (CW)<\/p>\n

    CW \u2013 Continous Wave Verfahren<\/p>\n

    P\u0159i t\u00e9to metod\u011b m\u011b\u0159en\u00ed je radarov\u00fd paprsek vys\u00edl\u00e1n a p\u0159ij\u00edm\u00e1n nep\u0159etr\u017eit\u011b a sou\u010dasn\u011b.
    To umo\u017e\u0148uje rozezn\u00e1vat pouze objekty s r\u016fzn\u00fdmi rychlostmi.
    Objekty se stejnou rychlost\u00ed se nerozli\u0161uj\u00ed.
    Nen\u00ed mo\u017en\u00e1 lokalizace.<\/p>\n

    2D \u2013 Radar<\/strong> (FSK)<\/p>\n

    FSK \u2013 Frequency Shift Key<\/p>\n

    Zde doch\u00e1z\u00ed k frekven\u010dn\u00edmu posunu.
    Jedn\u00e1 se o speci\u00e1ln\u00ed formu metody FMCW (viz 3D a 4D radar).
    To umo\u017e\u0148uje rozezn\u00e1vat pouze objekty s r\u016fznou rychlost\u00ed a vzd\u00e1lenost\u00ed.
    Objekty se stejnou rychlost\u00ed a vzd\u00e1lenost\u00ed se nerozli\u0161uj\u00ed.
    Lokalizace je mo\u017en\u00e1 na jednorozm\u011brn\u00e9 \u00farovni.<\/p>\n

    3D \u2013 Radar <\/strong>(FMCW-MIMO)<\/p>\n

    FMCW-MIMO \u2013 Frequency Modulated Continous Wave\u2013Multiple Input Multiple Output<\/p>\n

    P\u0159i t\u00e9to metod\u011b je frekvence modulov\u00e1na v z\u00e1vislosti na \u010dase a vys\u00edl\u00e1na pomoc\u00ed n\u011bkolika vys\u00edlac\u00edch a p\u0159ij\u00edmac\u00edch ant\u00e9n.
    Jak\u00fdkoli vys\u00edlan\u00fd sign\u00e1l m\u016f\u017ee b\u00fdt p\u0159ij\u00edm\u00e1n jakoukoli ant\u00e9nou.
    Speci\u00e1ln\u00ed uspo\u0159\u00e1d\u00e1n\u00ed n\u011bkolika ant\u00e9n zaji\u0161\u0165uje prostorov\u00e9 rozli\u0161en\u00ed a sni\u017euje n\u00e1chylnost k ru\u0161en\u00ed.
    Nyn\u00ed lze od sebe rozli\u0161it objekty s r\u016fznou rychlost\u00ed, vzd\u00e1lenost\u00ed a \u00fahlem.
    Rozli\u0161uj\u00ed se tak\u00e9 objekty se stejnou rychlost\u00ed, vzd\u00e1lenost\u00ed a stejn\u00fdm \u00fahlem.
    Lokalizace je mo\u017en\u00e1 na dvourozm\u011brn\u00e9 \u00farovni.<\/p>\n

    4D \u2013 Radar <\/strong>(FMCW-MIMO)<\/p>\n

    Dal\u0161\u00ed ant\u00e9ny ve v\u00fd\u0161ce umo\u017e\u0148uj\u00ed rozli\u0161it objekty i v\u00fd\u0161kov\u011b.
    Objekty tak lze lokalizovat v trojrozm\u011brn\u00e9m prostoru.<\/p>\n

    Radar \u2013 m\u011b\u0159iteln\u00e9 informace a vyhodnocen\u00ed<\/strong><\/p>\n

    Pomoc\u00ed technologie radarov\u00fdch senzor\u016f lze zaznamenat a vyhodnotit n\u00e1sleduj\u00edc\u00ed informace:<\/p>\n

      \n
    • rychlost objekt\u016f<\/li>\n
    • vzd\u00e1lenost objekt\u016f<\/li>\n
    • sm\u011br pohybu<\/li>\n
    • \u00fahel<\/li>\n<\/ul>\n

      Pomoc\u00ed inteligentn\u00edch algoritm\u016f je mo\u017en\u00e9 vytv\u00e1\u0159et tzv. historie pohybu.
      Objekty lze tak\u00e9 klasifikovat, tj. nap\u0159\u00edklad rozli\u0161it lidi od vozidel.

      V\u0161echny tyto informace jsou d\u016fle\u017eit\u00fdm stavebn\u00edm kamenem asisten\u010dn\u00edch syst\u00e9m\u016f pro \u0159\u00edzen\u00ed a stejn\u011b jako syst\u00e9my kamer, GPS a LiDAR tvo\u0159\u00ed jeden ze \u010dty\u0159 nosn\u00fdch pil\u00ed\u0159\u016f autonomn\u00edho \u0159\u00edzen\u00ed (AD).<\/p>\n

      Radar \u2013 oblasti pou\u017eit\u00ed<\/strong><\/p>\n

      Radar si na\u0161el cestu do mnoha oblast\u00ed vozidla.
      Ve v\u0161ech p\u0159\u00edpadech je v\u0161ak c\u00edlem dos\u00e1hnout \u201enulov\u00e9 nehodovosti\u201c.<\/p>\n

      Zde je p\u00e1r p\u0159\u00edpad\u016f:<\/p>\n\n\n\n\n\n\n\n\n\n\n\n\n
      ACC: Adaptive Cruise Control<\/td>\ntempomat s funkc\u00ed udr\u017eov\u00e1n\u00ed odstupu<\/td>\n<\/tr>\n
      AEB: Automatic Emergency Braking<\/td>\nasistent nouzov\u00e9ho brzd\u011bn\u00ed<\/td>\n<\/tr>\n
      FCW: Forward Collision Warning<\/td>\nvarov\u00e1n\u00ed p\u0159ed nehodou vp\u0159edu<\/td>\n<\/tr>\n
      CTA: Cross Traffic Alert<\/td>\nvarov\u00e1n\u00ed p\u0159ed vozidly v p\u0159\u00ed\u010dn\u00e9m sm\u011bru<\/td>\n<\/tr>\n
      ALC: Adaptive Light Control<\/td>\nadaptivn\u00ed osv\u011btlen\u00ed (osv\u011btlen\u00ed zat\u00e1\u010dky, automatick\u00e9 rozsv\u00edcen\u00ed a zhasnut\u00ed d\u00e1lkov\u00fdch sv\u011btel, …)<\/td>\n<\/tr>\n
      VEA: Vehicle – Exit Assist<\/td>\nvaruje p\u0159i opu\u0161t\u011bn\u00ed vozidla p\u0159ed bl\u00ed\u017e\u00edc\u00edmi se auty<\/td>\n<\/tr>\n
      BSD: Blind – Spot Detection<\/td>\nasistent slep\u00e9ho \u00fahlu<\/td>\n<\/tr>\n
      LCA: Lane – Change Assist at the rear<\/td>\nasistent zm\u011bny j\u00edzdn\u00edho pruhu vzadu<\/td>\n<\/tr>\n
      RCTA: Rear Cross Traffic Alert<\/td>\nvarov\u00e1n\u00ed p\u0159ed vozidly v p\u0159\u00ed\u010dn\u00e9m sm\u011bru vzadu<\/td>\n<\/tr>\n
      AVP: Automated Valet Parking<\/td>\nasistent parkov\u00e1n\u00ed<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n\t
      \n\t\t\n