Springer Tracts in Advanced Robotics 85 Editors Prof.BrunoSiciliano Prof.OussamaKhatib DipartimentodiInformatica ArtificialIntelligenceLaboratory eSistemistica DepartmentofComputerScience UniversitàdiNapoliFedericoII StanfordUniversity ViaClaudio21,80125Napoli Stanford,CA94305-9010 Italy USA E-mail:[email protected] E-mail:[email protected] Forfurthervolumes: http://www.springer.com/series/5208 EditorialAdvisoryBoard OliverBrock,TUBerlin,Germany HermanBruyninckx,KULeuven,Belgium RajaChatila,ISIR-UPMC&CNRS,France HenrikChristensen,GeorgiaTech,USA PeterCorke,QueenslandUniv.Technology,Australia PaoloDario,ScuolaS.AnnaPisa,Italy RüdigerDillmann,Univ.Karlsruhe,Germany KenGoldberg,UCBerkeley,USA JohnHollerbach,Univ.Utah,USA MakotoKaneko,OsakaUniv.,Japan LydiaKavraki,RiceUniv.,USA VijayKumar,Univ.Pennsylvania,USA SukhanLee,SungkyunkwanUniv.,Korea FrankPark,SeoulNationalUniv.,Korea TimSalcudean,Univ.BritishColumbia,Canada RolandSiegwart,ETHZurich,Switzerland GauravSukhatme,Univ.SouthernCalifornia,USA SebastianThrun,StanfordUniv.,USA YangshengXu,ChineseUniv.HongKong,PRC Shin’ichiYuta,TsukubaUniv.,Japan N SdeTrAtRhe(aSupsrpinicgeesrTofraEcUtsRinOANd(vEaunrcoepdeRanobRootbicost)ichsasRbeeseeanrpcrhoNmeottwedorukn)- RERuersoOepaeracBnhROO************TICS NetworkU E Radu Bogdan Rusu Semantic 3D Object Maps for Everyday Robot Manipulation ABC Author RaduBogdanRusu OpenPerception,Inc. SanFrancisco,CA USA ISSN1610-7438 e-ISSN1610-742X ISBN978-3-642-35478-6 e-ISBN978-3-642-35479-3 DOI10.1007/978-3-642-35479-3 SpringerHeidelbergNewYorkDordrechtLondon LibraryofCongressControlNumber:2012954153 (cid:2)c Springer-VerlagBerlinHeidelberg2013 Thisworkissubjecttocopyright.AllrightsarereservedbythePublisher,whetherthewholeorpartof thematerialisconcerned,specificallytherightsoftranslation,reprinting,reuseofillustrations,recitation, broadcasting,reproductiononmicrofilmsorinanyotherphysicalway,andtransmissionorinformation storageandretrieval,electronicadaptation,computersoftware,orbysimilarordissimilarmethodology nowknownorhereafterdeveloped.Exemptedfromthislegalreservationarebriefexcerptsinconnection with reviews or scholarly analysis or material supplied specifically for the purpose of being entered and executed on a computer system, for exclusive use by the purchaser of the work. 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Printedonacid-freepaper SpringerispartofSpringerScience+BusinessMedia(www.springer.com) Foreword Robotics is undergoing a major transformation in scope and dimension. From a largely dominant industrial focus, robotics is rapidly expanding into human envi- ronmentsandvigorouslyengagedinitsnewchallenges.Interactingwith,assisting, serving, and exploring with humans, the emerging robots will increasingly touch peopleandtheirlives. Beyondits impacton physicalrobots,the bodyof knowledgeroboticshaspro- duced is revealing a much wider range of applications reaching across diverse research areas and scientific disciplines, such as: biomechanics, haptics, neuro- sciences,virtualsimulation,animation,surgery,andsensornetworksamongothers. Inreturn,thechallengesofthenewemergingareasareprovinganabundantsource ofstimulationandinsightsforthefieldofrobotics.Itisindeedattheintersectionof disciplinesthatthemoststrikingadvanceshappen. TheSpringerTractsin AdvancedRobotics(STAR)isdevotedtobringingtothe research community the latest advances in the robotics field on the basis of their significance and quality. Through a wide and timely dissemination of critical re- searchdevelopmentsin robotics,ourobjectivewith this seriesis to promotemore exchanges and collaborations among the researchers in the community and con- tributetofurtheradvancementsinthisrapidlygrowingfield. The monograph by Radu Bogdan Rusu is a contribution aimed at developing novelrepresentationsofrobots’operatingenvironments.Thepromisingtechnology ofpointcloud-basedperceptionisintroducedtoderivesemantic3Dobjectmodels enabling complex mobile manipulation scenarios. Results are validated in a rich setofexperimentsondifferentrobotsperformingavarietyoftasksindynamically changing indoor environments, revealing a promising outlook toward the goal of employingautonomousrobotsineverydayhabitats. Remarkably,themonographisbasedontheauthor’sdoctoralthesis,whichwas a finalistforthe TenthEditionofthe EURONGeorgesGiraltPhDAward devoted tothebestPhDthesisinRoboticsinEurope.AveryfineadditiontoSTAR! Naples,Italy BrunoSiciliano October2012 STAREditor Abstract Environmentmodelsserveasimportantresourcesforanautonomousrobotbypro- viding it with the necessary task-relevant information about its habitat. Their use enablesrobotstoperformtheirtasksmorereliably,flexibly,andefficiently.Asau- tonomousroboticplatformsgetmoresophisticatedmanipulationcapabilities,they also needmoreexpressiveandcomprehensiveenvironmentmodels:formanipula- tionpurposestheirmodelshavetoincludetheobjectspresentintheworld,together with their position, form, and other aspects, as well as an interpretation of these objectswithrespecttotherobottasks. This book proposes Semantic 3D Object Models as a novel representation of therobot’soperatingenvironmentthatsatisfiestheserequirementsandshowshow these models can be automatically acquired from dense 3D range data. The book contributesin two importantways to the researcharea acquisitionof environment models. ThefirstcontributionisanovelframeworkforSemantic3DObjectModelacqui- sition from PointCloudData.The functionalityofthis frameworkincludesrobust alignmentandintegrationmechanismsforpartialdataviews,fastsegmentationinto regionsbasedonlocalsurfacecharacteristics,andreliableobjectdetection,catego- rization, and reconstruction.The computedmodelsare semantic in that they infer structuresinthedatathataremeaningfulwithrespecttotherobottask.Examplesof suchobjectsaredoorsandhandles,supportingplanes,cupboards,walls,ormovable smallerobjects. The second key contribution is point cloud representations based on 3D point feature histograms (3D-PFHs), which model the local surface geometry for each point.3D-PFHsdistinguishthemselvesfromalternative3Dfeaturerepresentations inthattheyareveryfasttocompute,robustagainstvariationsinposeandsampling density,andcopewellwithnoisysensordata.Theirusesubstantiallyimprovesthe qualityoftheSemantic3DObjectModelsacquired,aswellasthespeedwithwhich they are computed. 3D-PFHs come with specific software tools that allow for the learningofsurfacecharacteristicsbasedontheirunderlyinggeometry,theassembly ofmostdistinctive3Dpointsfromagivencloud,aswellaslimitedview-invariant correspondencesearchfor3Dregistration. The contributionspresentedin this bookhave been fullyimplementedand em- pirically evaluated on different robots performing different tasks in different en- vironments. The first demonstration relates to the problem of cleaning tables by disposing the objects on them into a garbagebin with a personalroboticassistant VIII Abstract in the presence of humans in its working space. The frameworkfor Semantic 3D ObjectModelacquisitionisdemonstratedandusedtoconstructdynamic3Dcolli- sionmaps,annotatethesurroundingworldwithsemanticlabels,andextractobject clusters supported by tables in real-time performance. The second demonstration presentsanon-the-flymodelacquisitionsystem for doorand handleidentification from noisy 3D point cloud maps. Experimental results show good robustness in the presence of large variations in the data, without suffering from the classical under or over-fitting problemsusually associated with similar initiatives based on machinelearningclassifiers. Thethirdapplicationexampletacklestheproblemof real-timesemanticmappingofindoorenvironmentswithdifferentkindsofterrain classes, suchas walkwaysandstairs, forthe navigationofa six-leggedrobotwith terrain-specificwalkingmodes. Contents Foreword . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . V Abstract. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . VII Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . IX ListofFigures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . XIII ListofTables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . XIX ListofAlgorithms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . XXI ListofSymbolsandNotations . . . . . . . . . . . . . . . . . . . . . . XXIII 1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.1 Why“3D”SemanticPerception? . . . . . . . . . . . . . . . . . 2 1.2 ComputationalProblems . . . . . . . . . . . . . . . . . . . . . 3 1.3 Publications . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 1.4 BookOutlineandContributions . . . . . . . . . . . . . . . . . 9 PartI Semantic 3DObject Mapping Kernel 2 3DMapRepresentations . . . . . . . . . . . . . . . . . . . . . . . 15 2.1 DataAcquisition . . . . . . . . . . . . . . . . . . . . . . . . . 15 2.2 DataRepresentation. . . . . . . . . . . . . . . . . . . . . . . . 20 2.3 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 3 MappingSystemArchitectures . . . . . . . . . . . . . . . . . . . . 27 4 3DPointFeatureRepresentations . . . . . . . . . . . . . . . . . . 33 4.1 The“Neighborhood”Concept . . . . . . . . . . . . . . . . . . 35 4.2 FilteringOutliers . . . . . . . . . . . . . . . . . . . . . . . . . 37 4.3 SurfaceNormalsandCurvatureEstimates . . . . . . . . . . . . 40 4.4 PointFeatureHistograms(PFH) . . . . . . . . . . . . . . . . . 44 4.5 FastPointFeatureHistograms(FPFH) . . . . . . . . . . . . . . 51 4.6 FeaturePersistence . . . . . . . . . . . . . . . . . . . . . . . . 54 X Contents 4.7 RelatedWork . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 4.8 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 5 FromPartialtoCompleteModels . . . . . . . . . . . . . . . . . . 61 5.1 PointCloudRegistration . . . . . . . . . . . . . . . . . . . . . 61 5.2 DataResampling . . . . . . . . . . . . . . . . . . . . . . . . . 68 5.3 RelatedWork . . . . . . . . . . . . . . . . . . . . . . . . . . . 73 5.4 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74 6 ClusteringandSegmentation . . . . . . . . . . . . . . . . . . . . . 75 6.1 FittingSimplifiedGeometricModels . . . . . . . . . . . . . . . 76 6.2 BasicClusteringTechniques . . . . . . . . . . . . . . . . . . . 78 6.3 FindingEdgesin3DData. . . . . . . . . . . . . . . . . . . . . 80 6.4 SegmentationviaRegionGrowing . . . . . . . . . . . . . . . . 81 6.5 ApplicationSpecificModelFitting . . . . . . . . . . . . . . . . 83 6.6 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85 PartII Mapping ofIndoorEnvironments 7 StaticSceneInterpretation . . . . . . . . . . . . . . . . . . . . . . 89 7.1 HeuristicRule-BasedFunctionalReasoning . . . . . . . . . . . 91 7.2 LearningtheSceneStructure . . . . . . . . . . . . . . . . . . . 100 7.3 ExportingandUsingtheModels . . . . . . . . . . . . . . . . . 105 7.4 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108 8 SurfaceandObjectClassLearning. . . . . . . . . . . . . . . . . . 109 8.1 LearningLocalSurfaceClasses. . . . . . . . . . . . . . . . . . 111 8.1.1 GeneratingTrainingData. . . . . . . . . . . . . . . . . 113 8.1.2 MostDiscriminativeFeatureSelection . . . . . . . . . . 115 8.1.3 SupervisedClassLearningUsingSupportVector Machines . . . . . . . . . . . . . . . . . . . . . . . . . 118 8.2 FastGeometricPointLabeling . . . . . . . . . . . . . . . . . . 123 8.3 GlobalFastPointFeatureHistogramsforObject Classification . . . . . . . . . . . . . . . . . . . . . . . . . . . 126 8.4 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136 9 ParametricShapeModelFitting . . . . . . . . . . . . . . . . . . . 137 9.1 ObjectSegmentation . . . . . . . . . . . . . . . . . . . . . . . 138 9.2 HybridShape-SurfaceObjectModels . . . . . . . . . . . . . . 141 9.3 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146 Contents XI PartIII Applications 10 TableCleaninginDynamicEnvironments . . . . . . . . . . . . . . 149 10.1 Real-TimeCollisionMapsforMotionRe-planning . . . . . . . 152 10.2 SemanticInterpretationof3DPointCloudMaps . . . . . . . . 154 10.3 SystemEvaluation . . . . . . . . . . . . . . . . . . . . . . . . 156 10.4 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159 11 IdentifyingandOpeningDoors . . . . . . . . . . . . . . . . . . . . 161 11.1 DetectingDoors . . . . . . . . . . . . . . . . . . . . . . . . . . 165 11.2 DetectingHandles. . . . . . . . . . . . . . . . . . . . . . . . . 167 11.3 SystemEvaluation . . . . . . . . . . . . . . . . . . . . . . . . 171 11.4 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175 12 Real-TimeSemanticMapsfromStereo . . . . . . . . . . . . . . . 177 12.1 LeavingFlatlandMappingArchitecture . . . . . . . . . . . . . 179 12.1.1 VisualOdometer . . . . . . . . . . . . . . . . . . . . . 181 12.1.2 SpatialDecomposition . . . . . . . . . . . . . . . . . . 184 12.1.3 PolygonalModeling . . . . . . . . . . . . . . . . . . . 186 12.1.4 MergingandRefinement . . . . . . . . . . . . . . . . . 187 12.1.5 SemanticLabeling . . . . . . . . . . . . . . . . . . . . 189 12.1.6 3DMappingPerformance . . . . . . . . . . . . . . . . 191 12.2 SemanticMapUsageandApplications . . . . . . . . . . . . . . 193 12.2.1 HybridModelVisualizations . . . . . . . . . . . . . . . 193 12.2.2 MotionPlanningforNavigation . . . . . . . . . . . . . 194 12.3 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 196 13 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 197 A 3DGeometryPrimer . . . . . . . . . . . . . . . . . . . . . . . . . 201 A.1 EuclideanGeometryandCoordinateSystems . . . . . . . . . . 201 A.2 DistanceMetrics . . . . . . . . . . . . . . . . . . . . . . . . . 202 A.3 GeometricShapes . . . . . . . . . . . . . . . . . . . . . . . . . 203 B SampleConsensus . . . . . . . . . . . . . . . . . . . . . . . . . . . 205 C MachineLearning . . . . . . . . . . . . . . . . . . . . . . . . . . . 207 C.1 SupportVectorMachines . . . . . . . . . . . . . . . . . . . . . 207 C.2 ConditionalRandomFields . . . . . . . . . . . . . . . . . . . . 210 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215