um ▁cleaner , ▁introduced ▁as ▁a ▁product ▁in ▁ 2 0 0 1 , ▁model ▁Z A 1 . ▁A ▁revision ▁was ▁released ▁as ▁Version ▁ 2 . 0 ▁in ▁ 2 0 0 4 , ▁model ▁Z A 2 . ▁ ▁Description ▁The ▁Tr il ob ite ▁contains ▁a ▁vac u um ▁cleaner ▁and ▁a ▁remov able ▁roll er ▁br ush ▁capable ▁of ▁working ▁on ▁deep - p ile ▁car pet . ▁It ▁has ▁the ▁ability ▁to ▁map ▁rooms ▁and ▁avoid ▁obst acles ▁by ▁using ▁ul tr ason ic ▁sens ors ▁( on ▁the ▁Mark ▁ 2 ▁model ▁also ▁inf ra red ). ▁It ▁re charg es ▁itself ▁on ▁a ▁charg ing ▁base , ▁which ▁it ▁automatically ▁finds ▁when ▁has ▁completed ▁its ▁clean ing ▁task ▁or ▁its ▁power ▁runs ▁low . ▁The ▁Tr il ob ite ▁will ▁indicate ▁when ▁the ▁dust bin ▁needs ▁to ▁be ▁em pt ied . ▁ ▁Its ▁ul tr ason ic ▁sens ors ▁allow ▁it ▁to ▁come ▁within ▁ 1 " ▁of ▁objects ▁without ▁coll iding ▁with ▁them . ▁This ▁object ▁detection ▁is ▁fairly ▁reliable , ▁but ▁sometimes ▁fails ▁if ▁the ▁robot ▁approaches ▁an ▁object ▁with ▁a ▁sharp ▁corner . ▁In ▁this ▁case , ▁the ▁ul tr ason ic ▁beam ▁is ▁not ▁reflected , ▁and ▁the ▁Tr il ob ite ▁will ▁g ently ▁b ump ▁into ▁the ▁object . ▁Because ▁the ▁Tr il ob ite ▁stops ▁a ▁short ▁distance ▁from ▁walls ▁and ▁other ▁objects , ▁it ▁leaves ▁small ▁areas ▁that ▁are ▁not ▁fully ▁clean ed . ▁ ▁Mag