AnIndustrial AugmentedReality Solution ForDiscrepancy Check

Construction companies employ CADsoftware during theplanning phase, butwhatisfinally built often doesnotmatchtheoriginal plan. Theprocedure ofvalidating themodeliscalled "discrepancy check". Thesystem proposed hereallows theusertoeasily obtain anaugmentation inorder tofind differences between theplanned 3Dmodelandthebuilt items. Themaindifference toprevious body ofworkinthis field istheemphasis onusability andacceptance of thesolution. Whilestandard image-based solutions usemarkers or rely ona"perfect" 3Dmodeltofind theposeofthecamera, our software usesAnchor-Plates. Anchor-Plates arerectangular structures installed onwalls andceiling inthemajority ofindustrial edifices. Weareusing themaslandmarks because theyarethemost reliable components often usedasreference coordinates byconstructors. Furthermore, forreal industrial applications, they arethe mostsuitable solutions interms ofgeneral applicability. Unfortunately, they havenotbeendesigned withComputer Vision applications inmind.Onthecontrary, they areoften madeorpainted in suchwaythat they arenoteasily popping out.Theyaretherefore difficult targets tosegment andtotrack. This paper proposes asolution toextract andmatch themtotheir 3Dcounterparts. Wecreated asoftware that usesthedetected structures forposeestimation andimageaugmentation. Thesoftware hasbeensuccessfully employed tofinddiscrepancies inseveral roomsoftwoindustrial plants.