An Augmented Framework for Practical Development of ... - InTechOpen

An Augmented Framework for Practical Development of Construction Robots ȱ

ȱ ȱ Khaled Zied EngineeringȱDepartment,ȱLancasterȱUniversity,ȱLancaster,ȱLA1ȱ4YR,ȱUK.ȱ AssistantȱProfessor,ȱMechanicalȱDesignȱDepartment,ȱHelwanȱUniversity,ȱCairo,ȱEgyptȱ [email protected]ȱ ȱ Abstract: Theȱ useȱ ofȱ roboticȱ systemsȱ inȱ performingȱ constructionȱ tasksȱ hasȱ greatȱ potential;ȱ howeverȱ theȱ developmentȱofȱsuchȱsystemsȱremainsȱproblematic.ȱThisȱisȱdueȱtoȱtheȱlackȱofȱaȱsuitableȱfeasibilityȱanalysisȱthatȱcanȱ helpȱtheȱdecisionȬmakersȱtoȱjustifyȱtheȱuseȱofȱrobotsȱandȱproblemsȱinȱtheȱdevelopmentȱprocessȱofȱtheȱsystemȱitself.ȱ Theȱ multidisciplinaryȱ andȱ complexȱ natureȱ ofȱ constructionȱ roboticȱ systemsȱ requiresȱ aȱ robustȱ developmentȱ frameworkȱforȱsuchȱsystems.ȱAnȱaugmentedȱframeworkȱforȱtheȱdevelopmentȱofȱconstructionȱrobotsȱisȱexplainedȱinȱ detailȱ andȱ practicallyȱ appliedȱ toȱ theȱ Starlifterȱ roboticȱ systemȱ whichȱ isȱ mainlyȱ designedȱ toȱ carryȱ heavyȱ toolsȱ forȱ constructionȱ tasks.ȱ Theȱ frameworkȱ consistsȱ ofȱ twoȱ models;ȱ theȱ feasibilityȱ analysisȱ modelȱ andȱ theȱ developmentȱ processȱ model.ȱ Theȱ feasibilityȱ analysisȱ principles,ȱ methodologyȱ andȱ toolsȱ areȱ explainedȱ andȱ discussedȱ inȱ detail.ȱ SystemsȱEngineeringȱmodelȱisȱusedȱinȱtheȱdevelopmentȱofȱtheȱsystemȱwhichȱallowsȱcompleteȱanalysisȱofȱtheȱsystemȱ hardwareȱandȱsoftwareȱcomponents.ȱTheȱpurposeȱofȱtheȱcurrentȱprojectȱisȱtoȱdevelopȱaȱgeneralȱpurposeȱrobotȱthatȱ canȱbeȱemployedȱtoȱperformȱdifferentȱjobsȱtoȱjustifyȱitsȱuseȱeconomically.ȱTheȱpresentedȱtoolsȱandȱprocessesȱcanȱbeȱ utilisedȱinȱtheȱdevelopmentȱofȱanyȱsimilarȱsystems.ȱȱ Keywords:ȱConstructionȱrobots,ȱDevelopmentȱmodels,ȱFeasibilityȱanalysis,ȱControllerȱdesign,ȱLabVIEWȱ

ȱ 1.ȱIntroductionȱȱ ȱ Constructionȱroboticsȱasȱaȱresearchȱfieldȱcouldȱbeȱsaidȱtoȱ haveȱ beenȱ establishedȱ inȱ 1984ȱ withȱ theȱ 1stȱ Internatonalȱ Symposiumȱ inȱ Automatiuonȱ andȱ Roboticsȱ inȱ Construction.ȱ Sinceȱ thatȱ time,ȱ manyȱ researchȱ andȱ developmentȱactivitiesȱhaveȱoccuredȱinȱmanyȱapplicationȱ areasȱ inȱ theȱ constructionȱ industry.ȱ Itȱ isȱ howeverȱ noticeableȱ thatȱ onlyȱ aȱ smallȱ numberȱ ofȱ constructionȱ robotsȱ haveȱ beenȱ commercialisedȱ andȱ implemented;ȱ reasonsȱ behindȱ thisȱ problemȱ areȱ identifiedȱ byȱ Seward,ȱ Sewardȱ (1999):ȱ 1)ȱ Natureȱ ofȱ constructionȱ applications,ȱ 2)ȱ Absenceȱ ofȱ integratedȱ ITȱ infrastructureȱ andȱ 3)ȱ Conservatismȱ inȱ acceptingȱ newȱ technologyȱ inȱ construction.ȱ Anotherȱ reasonȱ thatȱ couldȱ beȱ addedȱ toȱ theȱ aboveȱ isȱ theȱ lackȱ ofȱ methodologiesȱ andȱ toolsȱ thatȱ canȱ helpȱ inȱ theȱ assessmentȱofȱnewȱtechnologiesȱandȱautomatedȱsolutionsȱ thatȱ suitȱ theȱ natureȱ ofȱ constructionȱ activities.ȱ Regardingȱ theȱ thirdȱ reason,ȱ itȱ isȱ requiredȱ toȱ identifyȱ needsȱ andȱ benefitsȱ ofȱ usingȱ suchȱ technologyȱ inȱ performingȱ constructionȱ tasksȱ toȱ convinceȱ theȱ decisionȱ makerȱ toȱ adoptȱthisȱnewȱtechnology.ȱ Fourȱ majorȱ reasonsȱ areȱ identified,ȱ basedȱ onȱ theȱ workȱ doneȱ byȱ Kangariȱ andȱ Halpinȱ (1990)ȱ andȱ Thomasȱ (2002),ȱ whichȱreinforceȱtheȱuseȱofȱautomationȱinȱtheȱconstructionȱ industry:ȱ 1)ȱ Healthȱ andȱ safetyȱ riskȱ reduction,ȱ 2)ȱ Improvingȱ theȱ workingȱ environment,ȱ 3)ȱ Qualityȱ andȱ productivityȱimproving,ȱandȱ4)ȱCostȱreductionȱ Theȱ aboveȱ reasonsȱ obviouslyȱ reflectȱ theȱ natureȱ ofȱ constructionȱ tasksȱ whichȱ involveȱ hazardsȱ thatȱ affectȱ

personalȱ safetyȱ owingȱ toȱ theȱ natureȱ ofȱ constructionȱ sitesȱ orȱ theȱ characteristicsȱ specificȱ operationalȱ tasks.ȱ Theseȱ hazardsȱgenerateȱproblemsȱinȱrelationȱtoȱproductȱquality,ȱ productivityȱandȱhighȱwagesȱofȱlabour.ȱȱ Henceȱ theȱ developmentȱ ofȱ roboticȱ systemsȱ forȱ constructionȱ activitiesȱ facesȱ manyȱ barriersȱ whichȱ affectȱ theirȱ implementation.ȱ Theseȱ barriersȱ canȱ beȱ classifiedȱ asȱ technologicalȱbarriersȱandȱeconomicalȱbarriers.ȱȱ Theȱ technologicalȱ barriersȱ comeȱ fromȱ theȱ factȱ that,ȱ aȱ constructionȱ robotȱ mustȱ copeȱ withȱ theȱ complexityȱ ofȱ theȱ constructionȱprocessȱwhichȱinvolvesȱanȱunstructuredȱandȱ continuouslyȱevolvingȱsiteȱtogetherȱwithȱtheȱperformanceȱ ofȱ multipleȱ tasksȱ withȱ differingȱ characteristics.ȱ Thisȱ inȱ additionȱ toȱ theȱ replacementȱ ofȱ humanȱ labourȱ whichȱ requiresȱtheȱsystemȱtoȱhaveȱcertainȱlevelȱofȱintelligenceȱinȱ theȱformȱofȱanȱadvancedȱcontrolȱsystemȱandȱanȱintelligentȱ sensoryȱsystem.ȱȱ Taskȱ wiseȱ challengesȱ canȱ comeȱ fromȱ theȱ factȱ thatȱ itȱ isȱ requiredȱthatȱtheȱsystemȱȱadoptsȱtraditionalȱtechniquesȱofȱ performingȱ aȱ taskȱ inȱ orderȱ toȱ minimizeȱ theȱ numberȱ ofȱ changesȱtoȱoveralȱtaskȱperformance.ȱThisȱrequiresȱspecialȱ technicalȱ capabilitiesȱ toȱ beȱ availableȱ inȱ theȱ roboticȱ systems.ȱȱ Theȱ developmentȱ ofȱ roboticȱ systemsȱ forȱ constructionȱ activitiesȱ movesȱ inȱ differentȱ directionsȱ toȱ removeȱ theȱ technologicalȱ barriers.ȱ Theseȱ directionsȱ canȱ beȱ classifiedȱ as:ȱ 1. Developmentȱ ofȱ mobileȱ platformsȱ andȱ manipulatorsȱ 2. Developmentȱofȱadvancedȱcontrolȱsystemsȱ 3. Sensoryȱsystemsȱintegrationȱ

InternationalȱJournalȱofȱAdvancedȱRoboticȱSystems,ȱVol.ȱ4,ȱNo.ȱ4ȱ(2007)

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ISSNȱ1729Ȭ8806,ȱpp.ȱ477Ȭ500ȱ

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ȱInternationalȱJournalȱofȱAdvancedȱRoboticȱSystems,ȱVol.ȱ4,ȱNo.ȱ4ȱ(2007)ȱ ȱ

4. 5. 6.

ReȬengineeringȱ ofȱ processesȱ toȱ suitȱ roboticȱ systemsȱ Softwareȱ developmentȱ toȱ helpȱ inȱ theȱ aboveȱ aspectsȱofȱdevelopmentȱ Theȱ useȱ ofȱ advancedȱ ITȱ systemsȱ toȱ enhanceȱ theȱ wholeȱsystemȱperformanceȱ

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Economicalȱjustificationȱofȱtheȱuseȱofȱaȱroboticȱsystemȱinȱ performingȱconstructionȱtasksȱisȱtheȱdrivingȱforceȱforȱtheȱ finalȱ implementationȱ ofȱ theȱ system.ȱ Economicalȱ barriersȱ forȱtheȱfinalȱimplementationȱofȱsuchȱaȱsystemȱcomeȱfromȱ theȱ requirementȱ ofȱ anȱ evaluationȱ techniqueȱ toȱ coverȱ theȱ followingȱaspects:ȱNeilȱetȱalȱ(1993)ȱ 1. Theȱdirectȱcostȱorȱbenefitsȱ 2. Theȱeffectȱofȱtheȱnewȱsystemȱonȱtheȱorganizationȱ suchȱ asȱ technologyȱ strategyȱ ȱ complyingȱ withȱ healthȱ andȱ safetyȱ regulationsȱ andȱ labourȱ organizationsȱfactorsȱ 3. Theȱrequiredȱchangesȱforȱimplementationȱofȱtheȱ newȱsystemȱ ȱ

Inȱ mostȱ casesȱ itȱ isȱ requiredȱ toȱ removeȱ theȱ technologicalȱ barriersȱ toȱ beȱ ableȱ toȱ adoptȱ anȱ economicalȱ evaluationȱ technique.ȱ Howeverȱ withȱ theȱ helpȱ ofȱ feasibilityȱ analysisȱ modelsȱ itȱ isȱ possibleȱ toȱ provideȱ guidelinesȱ forȱ theȱ decisionȱ makersȱ toȱ thinkȱ aboutȱ theȱ roboticȱ automationȱ solution.ȱ Manyȱapplicationȱareasȱinȱtheȱconstructionȱindustryȱhaveȱ beenȱidentifiedȱbyȱpreviousȱauthors,ȱKangariȱandȱHalpinȱ (1990),ȱ Sewardȱ (1999)ȱ andȱ Thomasȱ etȱ alȱ (2002),ȱ asȱ candidatesȱforȱautomationȱorȱrobotizationȱorȱasȱexamplesȱ ofȱalreadyȱdevelopedȱprocesses.ȱȱ Sewardȱ(1999)ȱlistedȱdifferentȱareasȱforȱautomationȱbasedȱ onȱ aȱ reviewȱ ofȱ constructionȱ roboticsȱ developedȱ byȱ Wingȱ (1989).ȱ Thisȱ listȱ includesȱ roboticȱ systemsȱ developedȱ inȱ differentȱareasȱasȱfollows:ȱ 1. Assembly,ȱ manipulationȱ andȱ materialȱ handlingȱ andȱjoiningȱ 2. Inspection,ȱmaintenanceȱandȱsurveyingȱ 3. Spraying,ȱfinishingȱandȱcleaningȱ 4. Roadȱworksȱandȱtunnellingȱ 5. Earthȱworks,ȱminingȱandȱdemolitionȱȱ

Thisȱ workȱ identifiedȱ manyȱ otherȱ applicationsȱ areasȱ mentionedȱbyȱotherȱauthorsȱwhichȱmainlyȱincludeȱsafetyȱ riskȱ relatedȱ applications.ȱ Theȱ mainȱ objectiveȱ inȱ theȱ Thomasȱ studyȱ isȱ toȱ identifyȱ areasȱ asȱ candidatesȱ forȱ automationȱtoȱcomplyȱwithȱhealthȱandȱsafetyȱregulations.ȱȱ Otherȱ automationȱ opportunitiesȱ identifiedȱ byȱ Kangariȱ andȱ Gregoryȱ (1997)ȱ andȱ Espositoȱ etȱ alȱ (1993)ȱ inȱ theȱ fieldȱ ofȱ military’ȱ environmentalȱ operationsȱ andȱ hazardousȱ wasteȱ management.ȱ Threeȱ areasȱ areȱ specificallyȱ mentioned:ȱ (1)ȱ areaȱ clearanceȱ (2)ȱ unexplodedȱ ordnanceȱ removalȱandȱ(3)ȱhazardousȱwasteȱremoval.ȱ Theȱ presentȱ workȱ isȱ focusingȱ onȱ identifyingȱ methodologiesȱ andȱ toolsȱ toȱ helpȱ inȱ acceleratingȱ theȱ developmentȱ processȱ ofȱ constructionȱrobots.ȱ Theȱ presentȱ workȱisȱbasedȱonȱtheȱuseȱofȱtwoȱmodels,ȱfeasibilityȱanalysisȱ modelȱ andȱ systemsȱ engineeringȱ model.ȱ Theȱ feasibilityȱ analysisȱmodelȱisȱdesignedȱultimatelyȱtoȱjustifyȱtheȱuseȱofȱ roboticȱ automationȱ fromȱ differentȱ perspectives.ȱ Theȱ systemsȱ engineeringȱ modelȱ isȱ designatedȱ toȱ helpȱ inȱ engineeringȱ ofȱ roboticȱ systemsȱ asȱ multidisciplinaryȱ systemsȱ toȱ complyȱ withȱ theȱ technologicalȱ requirementsȱ identifiedȱ above.ȱ Theȱ presentȱ workȱ isȱ basedȱ onȱ practicalȱ implementationȱofȱtheȱtwoȱmodelsȱandȱtheȱuseȱofȱrealȱlifeȱ applicationsȱandȱcontractsȱasȱcaseȱstudies.ȱ Starlifterȱ robot,ȱ theȱ firstȱ robotȱ inȱ theȱ worldȱ designedȱ specificallyȱ forȱ theȱ deploymentȱ ofȱ heavyȱ toolsȱ inȱ constructionȱ sites,ȱ isȱ usedȱ asȱ anȱ exampleȱ ofȱ constructionȱ roboticsȱtoȱpracticallyȱvalidateȱtheȱtwoȱ modelsȱidentifiedȱ above.ȱȱ ȱ 2.ȱTheȱStarlifterȱRobotȱ ȱ Starlifterȱ isȱ theȱ firstȱ robotȱ inȱ theȱ worldȱ speciallyȱ designedȱforȱperformingȱconstructionȱtasksȱȬȱseeȱFig.ȱ1.ȱInȱ thisȱ sectionȱ aȱ detailedȱ descriptionȱ ofȱ theȱ robotȱ isȱ presentedȱinȱtermsȱofȱkinematics,ȱdrives,ȱcontrolȱetc.ȱTheȱ purposeȱofȱthisȱdescriptionȱisȱtoȱanalyseȱandȱevaluateȱtheȱ systemȱ componentsȱ toȱ emphasizeȱ theȱ robotȱ designȱ philosophyȱ toȱ determineȱ aȱ startingȱ pointȱ forȱ theȱ futureȱ development.ȱȱ ȱ

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Theȱ aboveȱ listȱ wasȱ explainedȱ inȱ detailȱ withȱ examplesȱ ofȱ alreadyȱ developedȱ systemsȱ orȱ systemsȱ stillȱ underȱ development.ȱ Inȱ additionȱ toȱ theȱ aboveȱ applicationȱ areas,ȱ Kangariȱ andȱ Halpinȱ identifiedȱ otherȱ areasȱ suchȱ as,ȱ offȬ shoreȱ oceanȱ floorȱ construction,ȱ excavationȱ forȱ gasȱ lineȱ installationȱandȱcraterȱrepairȱofȱbombȱdamagedȱrunways.ȱȱ OtherȱareasȱareȱproposedȱbyȱThomasȱ(2002)ȱasȱcandidatesȱ forȱ automationȱ basedȱ onȱ aȱ questionnaireȱ ofȱ peopleȱ fromȱ theȱ constructionȱ industryȱ inȱ theȱ Northȱ Westȱ ofȱ England.ȱ Theȱ resultsȱ ofȱ thisȱ questionnaireȱ haveȱ identifiedȱ theȱ followingȱapplicationȱareas:ȱ 1. Siteȱclearanceȱandȱwasteȱmanagementȱ 2. Siteȱpreparationȱforȱsafeȱoperationȱ 3. Subȱsurfaceȱworksȱsuchȱasȱdeepȱdrainagesȱwhichȱ includesȱmanyȱhazardsȱ 4. Unloading,ȱtransport,ȱliftingȱandȱcommissioningȱ

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ȱ Fig.ȱ1ȱTheȱStarlifterȱRobotȱ

KhaledȱZiedȱ/ȱAnȱAugmentedȱFrameworkȱforȱPracticalȱDevelopmentȱofȱConstructionȱRobotsȱ ȱ

2.1ȱStarlifterȱdesignȱobjectivesȱȱ ThereȱareȱmanyȱdesignȱobjectivesȱofȱStarlifterȱrobotȱsuchȱ as:ȱ 1. Providingȱ aȱ stableȱ platformȱ forȱ theȱ toolȱ whileȱ performingȱtheȱtaskȱ 2. Carryingȱ capacityȱ ofȱ upȱ toȱ 200ȱ kgȱ atȱ anyȱ orientationȱofȱjointȱ1ȱ 3. Portabilityȱ 4. ReȬconfigurableȱendȬeffectorȱ 5. Remoteȱcontrolȱ 6. Modularityȱȱ

ȱ Theseȱ designȱ objectivesȱ controlledȱ theȱ size,ȱ theȱ weightȱ andȱtheȱcostȱofȱStarlifterȱrobot.ȱForȱexample,ȱdesigningȱforȱ aȱstableȱplatformȱrequiredȱaȱstrongȱandȱrigidȱstructureȱofȱ theȱrobotȱlinksȱasȱwellȱasȱtheȱrobotȱjoints.ȱDesigningȱforȱaȱ payloadȱofȱ200ȱkgȱrequiredȱtheȱuseȱofȱpowerfulȱactuatorsȱ toȱsupportȱtheȱinitialȱweightȱofȱtheȱrobotȱandȱtoȱcarryȱtheȱ designatedȱ payload.ȱ Theȱ sizeȱ ofȱ anȱ actuatorȱ isȱ proportionalȱ toȱ theȱ loadȱ itȱ canȱ carryȱ i.e.ȱ theȱ biggerȱ theȱ loadȱ theȱ biggerȱ theȱ sizeȱ ofȱ theȱ actuatorȱ whichȱ willȱ beȱ reflectedȱ onȱ theȱ totalȱ sizeȱ andȱ weightȱ ofȱ theȱ robot.ȱ Designingȱ forȱ aȱ reȬconfigurableȱ endȬeffectorȱ andȱ modularityȱ requiredȱ theȱ useȱ ofȱ advancedȱ technology,ȱ whichȱ resultsȱ inȱ higherȱ cost.ȱ Theȱ analysisȱ ofȱ theȱ existingȱ systemȱincludesȱtheȱidentificationȱofȱtheȱrobotȱkinematicalȱ structureȱ andȱ theȱ componentsȱ usedȱ toȱ driveȱ andȱ controlȱ theȱrobotȱmotion.ȱ Starlifterȱ isȱ aȱ sixȬdegreeȱ ofȱ freedomȱ robotȱ withȱ sixȱ revoluteȱ joints.ȱ Theȱ kinematicalȱ layoutȱ ofȱ Starlifterȱ isȱ similarȱ toȱ theȱ structureȱ ofȱ anȱ elbowȱ robotȱ describedȱ byȱ Paulȱ(1982).ȱȱ Theȱ designȱ philosophyȱ ofȱ Starlifterȱ isȱ centredȱ onȱ compactnessȱi.e.ȱtheȱrobotȱarterialȱconnections,ȱvalvesȱandȱ actuatorsȱ mustȱ beȱ includedȱ insideȱ theȱ robotȱ links.ȱ Noȱ externalȱ hosesȱ andȱ noȱ exposedȱ connections.ȱ Thisȱ philosophyȱ reflectedȱ onȱ theȱ sizeȱ andȱ theȱ shapeȱ ofȱ theȱ robotȱ linksȱ andȱ joints.ȱ BoxȬshapedȱ linksȱ areȱ madeȱ toȱ containȱallȱtheȱrequiredȱcomponentsȱinsideȱtheȱlinks.ȱTheȱ outerȱframesȱandȱtheȱsideȱplatesȱofȱtheȱlinksȱareȱmadeȱofȱ steelȱ toȱ supportȱ theȱ bendingȱ loadsȱ inducedȱ dueȱ toȱ theȱ linksȱ selfȬweightȱ andȱ theȱ payloadȱ atȱ theȱ robotȱ tip.ȱ Theȱ outerȱ caseȱ ofȱ theȱ linksȱ andȱ theȱ jointȱ coversȱ areȱ madeȱ ofȱ aluminium.ȱ Starlifterȱ canȱ reachȱ aȱ heightȱ ofȱ 3.80ȱ mȱ atȱ fullȱ extensionȱ fromȱ theȱ groundȱ levelȱ withȱ theȱ currentȱ baseȱ structure.ȱ Thisȱ reachȱ canȱ beȱ achievedȱ withoutȱ anyȱ attachmentȱ toȱ itsȱ tipȱ withȱ fullȱ stabilityȱ ofȱ theȱ baseȱ structure.ȱThisȱreachȱcanȱbeȱextendedȱtoȱhigherȱpositionsȱ accordingȱ toȱ theȱ attachedȱ toolȱ dimensionsȱ andȱ weight.ȱ Equilibriumȱandȱstabilityȱofȱtheȱrobotȱdominatesȱitsȱreachȱ andȱloadȱcapacity.ȱȱ Hydraulicȱ powerȱ isȱ usedȱ toȱ operateȱ Starlifterȱ robotȱ toȱ sustainȱ theȱ requiredȱ payloadȱ andȱ theȱ robotȱ inertia.ȱ Mostȱ largeȱ scaleȱ industrialȱ andȱ constructionȱ robotsȱ areȱ hydraulicallyȱ powered,ȱ especiallyȱ thoseȱ withȱ highȱ carryingȱloadȱcapacityȱHassȱandȱHsiehȱ(1993).ȱRotaryȱandȱ linearȱ actuatorsȱ areȱ usedȱ toȱ moveȱ theȱ robotȱ joints.ȱ

Starlifterȱisȱoperatedȱusingȱaȱstandardȱhydraulicȱportableȱ powerȱpack,ȱelectricallyȱpoweredȱbyȱaȱthreeȬphaseȱpowerȱ source.ȱ Thisȱ powerȱ packȱ canȱ deliverȱ oilȱ atȱ theȱ rateȱ ofȱ 60ȱ litres/minȱ atȱ maximumȱ pressureȱ ofȱ 220ȱ bar.ȱ Theȱ powerȱ packȱ isȱ equippedȱ withȱ aȱ dumpȱ valveȱ toȱ cutȱ theȱ outputȱ flowȱwhenȱitȱisȱnecessaryȱwhileȱtheȱpumpȱisȱrunning.ȱItȱisȱ alsoȱ equippedȱ withȱ anȱ emergencyȱ stopȱ toȱ cutȱ theȱ powerȱ inȱ caseȱ ofȱ undesiredȱ motionȱ ofȱ theȱ robotȱ orȱ anyȱ otherȱ safetyȱrelatedȱproblems.ȱ ThreeȱmodesȱofȱcontrolȱareȱusedȱforȱcontrollingȱStarlifterȱ motions.ȱ Theseȱ threeȱ modesȱ cannotȱ beȱ usedȱ simultaneously.ȱTheseȱmodesȱare:ȱ 1. Directȱjointȱcontrolȱ(manualȱcontrol)ȱ 2. Teleoperationȱcontrolȱ(Joystickȱcontrol)ȱ 3. PreȬprogrammedȱ motionȱ controlȱ (taskȱ languageȱ control)ȱȱ ȱ Theȱ firstȱ modeȱ ofȱ operationȱ isȱ usedȱ duringȱ testingȱ andȱ maintenanceȱofȱStarlifterȱinȱwhichȱaȱmanualȱcontrolȱboxȱisȱ usedȱ toȱ sendȱ signalsȱ toȱ theȱ valvesȱ directlyȱ usingȱ aȱ setȱ ofȱ potentiometers.ȱTheȱsecondȱandȱtheȱthirdȱmodesȱcanȱonlyȱ beȱ usedȱ throughȱ aȱ highȱ levelȱ controllerȱ calledȱ ATCȱ (Advancedȱ Teleoperationȱ Controller)ȱ developedȱ byȱ UKȱ ROBOTICSȱ Ltd.ȱ Theȱ ATCȱ controllerȱ utilizesȱ aȱ PIDȱ controllerȱoperatedȱbyȱaȱservoȱcontroller.ȱȱ Aȱseriesȱofȱtestsȱareȱcarriedȱoutȱtoȱproveȱtheȱfunctionalityȱ againstȱ theȱ designȱ objectives.ȱ Theȱ firstȱ testȱ isȱ carriedȱ outȱ toȱtestȱtheȱarmȱperformanceȱwhileȱcarryingȱtheȱmaximumȱ payloadȱ ofȱ 200ȱ kg.ȱ Fig.ȱ 2ȱ showsȱ Starlifterȱ carryingȱ testȱ weightsȱ atȱ differentȱ configurationsȱ ofȱ theȱ arm.ȱ Itȱ canȱ beȱ noticedȱthatȱtheȱtestȱweightȱisȱaȱbalancedȱweightȱinȱwhichȱ theȱmomentȱatȱtheȱendȬeffectorȱplateȱisȱuniform.ȱHoweverȱ theseȱ testsȱ areȱ carriedȱ outȱ atȱ criticalȱ configurationsȱ inȱ whichȱ aȱ nonȬuniformȱ momentȱ atȱ theȱ robotȱ linksȱ isȱ induced.ȱ Theseȱ testsȱ showȱ greatȱ stabilityȱ ofȱ theȱ armȱ atȱ theseȱ configurations.ȱ Theȱ secondȱ testȱ ofȱ Starlifterȱ isȱ theȱ payloadȱ stabilityȱ usingȱ theȱ actualȱ HILTIȱ toolsȱ (upȱ toȱ 120ȱ kg)ȱ Inȱ thisȱ test,ȱ theȱ robotȱ showsȱ greatȱ flexibilityȱ inȱ manoeuvringȱ theȱ toolsȱ evenȱ forȱ longȱ extensionsȱ ofȱ theȱ toolȱrailȱasȱinȱtheȱcaseȱofȱtheȱHILTIȱplungeȱsaw.ȱ ȱ ȱ ȱ

ȱ Fig.ȱ2ȱStarlifterȱpayloadȱtestȱ

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3.ȱFeasibilityȱAnalysisȱModelȱ Theȱ adoptionȱ ofȱ newȱ technologyȱ inȱ theȱ constructionȱ industryȱ mustȱ beȱ followedȱ byȱ definiteȱ benefitsȱ thatȱ willȱ motivateȱ theȱ managementȱ toȱ takeȱ theȱ decisionȱ toȱ moveȱ forwardȱinȱusingȱthisȱtechnology.ȱAsȱanȱexampleȱofȱtheseȱ benefitsȱ thoseȱ mentionedȱ aboveȱ inȱ theȱ comparisonȱ betweenȱ theȱuseȱ ofȱ diamondȱ coreȱdrillingȱ andȱ theȱ useȱ ofȱ conventionalȱ methodsȱ ofȱ demolitionȱ inȱ termsȱ ofȱ timeȱ reduction,ȱ structureȱ integrity,ȱ labourȱ safetyȱ etc.ȱ Theseȱ benefitsȱ madeȱ theȱ decisionȱ makersȱ adoptȱ theȱ diamondȱ cuttingȱ technology.ȱ Forȱ anyȱ constructionȱ taskȱ itȱ isȱ notȱ easyȱ toȱ judgeȱ theȱ immediateȱ benefitsȱ ofȱ usingȱ newȱ technologyȱunlessȱaȱcompleteȱanalysisȱandȱevaluationȱareȱ performedȱtoȱdefineȱtheȱneedsȱandȱbenefits.ȱ ȱ 3.1ȱModelȱdescriptionȱ Inȱ theȱ presentȱ work,ȱ anȱ integratedȱ systematicȱ modelȱ isȱ developedȱ toȱ helpȱ theȱ decisionȱ makersȱ toȱ analysis,ȱ evaluateȱ andȱ decideȱ theȱ implementationȱ ofȱ newȱ automationȱ technology.ȱ Theȱ feasibilityȱ analysisȱ modelȱ basicallyȱ consistsȱ ofȱ fourȱ stagesȱ namely;ȱ needȱ analysis,ȱ decisionȬmaking,ȱ technologyȱ approvalȱ andȱ economicȱ analysisȱasȱshownȱinȱFig.ȱ3.ȱ Inȱ theȱ needȱ analysisȱ stage,ȱ comprehensiveȱ analysesȱ shouldȱ beȱ madeȱ toȱ identifyȱ theȱ taskȱ characteristicsȱ andȱ particularsȱ andȱ theȱ levelȱ orȱ levelsȱ ofȱ automationȱ theȱ automatedȱtaskȱisȱgoingȱtoȱuse.ȱTheȱoutputsȱofȱthisȱstageȱ are:ȱfirstlyȱalternativesȱforȱperformingȱtheȱtaskȱ(thisȱcouldȱ includeȱ theȱ recommendationȱ ofȱ useȱ aȱ refinedȱ versionȱ ofȱ theȱ conventionalȱ methodsȱ ofȱ carryingȱ outȱ theȱ task,ȱ orȱ evenȱ toȱ useȱ theȱ conventionalȱ methodsȱ asȱ theyȱ are).ȱ Secondly,ȱselectionȱcriteriaȱforȱtheȱdecisionȱmakingȱ stageȱ forȱeachȱalternative.ȱTheseȱcriteriaȱbasedȱonȱriskȱanalysisȱ andȱoperationȱcharacteristicsȱidentification.ȱȱ ȱ ȱ Need Analysis Task Analysis

Environment Variables

Automation Levels

Criteria &Alternatives Decision Making No Automation Use Traditional Methods

Yes

Technology Approval

Economic Analysis

Not feasible

Feasible Implementation ȱ

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Fig.ȱ3ȱFeasibilityȱanalysisȱmodelȱ

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ȱ

Theȱ alternativesȱ andȱ theirȱ selectionȱ criteriaȱ togetherȱ areȱ goingȱtoȱbeȱpassedȱtoȱtheȱdecisionȱmakingȱprocessȱwhichȱ usesȱ methodsȱ suchȱ asȱ AHPȱ (Analyticȱ Hierarchyȱ Process)ȱ whichȱ isȱ usefulȱ inȱ caseȱ ofȱ multipleȱ criteria/alternativesȱ problems.ȱInterviewȬbasedȱquestionnairesȱareȱmadeȱwithȱ expertsȱ orȱ peopleȱ inȱ theȱ fieldȱ toȱ whichȱ theȱ taskȱ underȱ studyȱisȱrelated.ȱThisȱapproachȱisȱusuallyȱemployedȱwhenȱ usingȱ theȱ AHPȱ methodology,ȱ Saaty,ȱ 1980.ȱ Theȱ alternativesȱ andȱ criteriaȱ shouldȱ beȱ strictlyȱ definedȱ forȱ particularȱ casesȱ andȱ notȱ beȱ generic.ȱ Theȱ expertsȱ inȱ theȱ fieldȱ areȱ knowledgeableȱ ofȱ theȱ conventionalȱ methodsȱ howeverȱ theyȱ shouldȱ beȱ awareȱ andȱ beȱ givenȱ enoughȱ informationȱ aboutȱ theȱ newȱ technology;ȱ otherwiseȱ itȱ wouldȱ notȱ beȱ easyȱ toȱ getȱ reliableȱ informationȱ aboutȱ theȱ needsȱ andȱ benefitsȱ ofȱ usingȱ suchȱ aȱ newȱ technology.ȱ Demonstrationȱ ofȱ theȱ newȱ technologyȱ isȱ requiredȱ toȱ getȱ reliableȱ information.ȱ Thisȱ couldȱ beȱ doneȱ usingȱ existingȱ productionȱ versionsȱ ofȱ theȱ technology,ȱ aȱ workingȱ prototypeȱ orȱ atȱ leastȱ reliableȱ simulationsȱ ofȱ theȱ technologyȱifȱitȱisȱstillȱunderȱdevelopment.ȱȱ Theȱoutcomeȱfromȱtheȱdecisionȱmakingȱprocessȱsupportsȱ theȱ useȱ ofȱ oneȱ ofȱ theȱ alternatives,ȱ whichȱ couldȱ beȱ theȱ traditionalȱ method,ȱ howeverȱ ifȱ theȱ decisionȬmakingȱ processȱsuggestedȱtheȱuseȱofȱautomation,ȱfurtherȱanalysisȱ shouldȱ beȱ done.ȱ Forȱ theȱ electedȱ levelȱ ofȱ automationȱ aȱ technologyȱ approvalȱ procedureȱ willȱ beȱ employedȱ toȱ identifyȱtheȱdetailsȱofȱtheȱautomationȱlevelȱinȱtermsȱofȱtheȱ roboticsȱ systemȱ requirementsȱ toȱ satisfyȱ theȱ workingȱ conditionsȱ specifiedȱ inȱ theȱ needȱ analysisȱ process.ȱ Theȱ roboticȱ systemȱ requirementsȱ forȱ aȱ certainȱ levelȱ includeȱ fiveȱ modulesȱ identifiedȱ byȱ Espositoȱ etȱ alȱ suchȱ asȱ Locomotion,ȱ roboticȱ platform,ȱ sensors,ȱ controllerȱ andȱ endeffector.ȱ Theseȱ fiveȱ modulesȱ varyȱ fromȱ levelȱ ofȱ automationȱ toȱ another,ȱ forȱ exampleȱ forȱ aȱ basicȱ levelȱ ofȱ automation;ȱ theseȱ modulesȱ couldȱ beȱ reducedȱ toȱ aȱ manipulator,ȱ aȱ teleoperatorȱ controllerȱ andȱ aȱ simpleȱ graspingȱ endeffector.ȱ Forȱ aȱ higherȱ levelȱ ofȱ automationȱ aȱ mobileȱ platformȱ canȱ beȱ integratedȱ toȱ doȱ theȱ locomotionȱ functionȱwithȱsensorȱguidedȱcontrollerȱandȱautomaticȱtoolȱ changerȱendeffector.ȱȱ Itȱ isȱ necessaryȱ toȱ lookȱ atȱ theȱ availableȱ technologyȱ andȱ howȱfarȱitȱcanȱbeȱpracticallyȱimplemented.ȱInȱthisȱstageȱaȱ detailedȱ architectureȱ ofȱ theȱ systemȱ mustȱ beȱ identifiedȱ toȱ enableȱ theȱ economicȱ evaluationȱ ofȱ theȱ levelȱ orȱ levelsȱ ofȱ automationȱunderȱstudy.ȱTheȱeconomicȱanalysisȱincludesȱ theȱcomparisonȱofȱtheȱcostȱassociatedȱinȱperformingȱaȱtaskȱ usingȱtheȱtraditionalȱmethodsȱandȱtheȱ suggestedȱlevelȱofȱ automation.ȱTheȱoutputȱfromȱtheȱeconomicȱanalysisȱstageȱ willȱ approveȱ theȱ implementationȱ ofȱ theȱ suggestedȱ levelȱ automationȱ fromȱ theȱ economicȱ pointȱ ofȱ viewȱ orȱ toȱ goȱ backȱtoȱlookȱtoȱtheȱotherȱalternativeȱtechnologyȱproducedȱ byȱ theȱ technologyȱ approvalȱ stageȱ andȱ continueȱ theȱ loopȱ untilȱ aȱ satisfactoryȱ outputȱ isȱ achieved.ȱ Theȱ decisionȱ makers’ȱroleȱisȱveryȱimportantȱatȱthisȱstageȱ becauseȱtheyȱ haveȱtangibleȱresultsȱthatȱtheyȱcanȱrelyȱonȱfromȱdifferentȱ pointsȱofȱview.ȱȱ ȱ ȱ


ȱ Inȱ theȱ presentȱ workȱ aȱ comprehensiveȱ feasibilityȱ analysisȱ isȱcarriedȱoutȱtoȱjustifyȱtheȱuseȱofȱStarlifterȱroboticȱsystemȱ inȱconcreteȱcoreȱdrillingȱandȱsawing.ȱTheȱanalysisȱisȱbasedȱ onȱ caseȱ studiesȱ fromȱ contractorsȱ whoȱ useȱ traditionalȱ methods.ȱ Detailsȱ ofȱ theȱ caseȱ studiesȱ andȱ theȱ outcomeȱ fromȱ theȱ feasibilityȱ analysisȱ wereȱ presentedȱ inȱ previousȱ workȱbyȱZiedȱandȱSewardȱ(2003).ȱTheȱfeasibilityȱanalysisȱ resultsȱ presentedȱ inȱ thisȱ wasȱ inȱ favourȱ ofȱ theȱ useȱ ofȱ theȱ automatedȱprocess.ȱȱ Earlierȱ studyȱ carriedȱ outȱ byȱ Ziedȱ etȱ alȱ (2001)ȱ onȱ theȱ economicȱfeasibilityȱofȱtheȱuseȱofȱStarlifterȱroboticȱsystemȱ inȱ coreȱ drillingȱ underneathȱ aȱ motorwayȱ bridgeȱ showedȱ thatȱ theȱ roboticȱ solutionȱ isȱ moreȱ economicȱ inȱ theȱ shortȱ termȱbasedȱonȱhiringȱtheȱsystem.ȱTheȱstudyȱwasȱbasedȱonȱ costȱ estimationȱ basedȱ onȱ graphicalȱ simulationȱ ofȱ theȱ proposedȱ system.ȱ Moreȱ economicȱ analysisȱ couldȱ beȱ carriedȱ outȱ forȱ furtherȱ justificationȱ usingȱ theȱ sameȱ methodȱforȱotherȱcaseȱstudies.ȱ Theȱoutcomeȱfromȱtheȱfeasibilityȱanalysisȱpresentedȱhereȱ onȱtheȱwholeȱshowedȱthatȱitȱisȱjustifiedȱforȱtheȱsystemȱtoȱ moveȱtoȱtheȱnextȱstageȱofȱtheȱdevelopmentȱprocess.ȱ

forȱ decommissioningȱ makeȱ itȱ aȱ multidisciplinaryȱ systemȱ inȱwhichȱtheȱselectionȱofȱaȱdevelopmentȱmodelȱbasedȱonȱ onlyȱoneȱmoduleȱisȱnotȱappropriate,ȱZied,ȱ2004.ȱȱ Theȱsystemȱdevelopmentȱlifeȱcycleȱcanȱbeȱillustratedȱasȱaȱ sequenceȱofȱactionsȱtoȱbeȱtakenȱthatȱstartsȱfromȱtheȱsystemȱ objectiveȱandȱresultsȱinȱtheȱfinalȱoperationȱofȱtheȱsystem.ȱ Inȱbetweenȱtheseȱactionsȱaȱreviewȱofȱtheȱcompletedȱstepsȱ inȱtheȱformȱofȱfeedbackȱshouldȱbeȱmadeȱbeforeȱmovingȱtoȱ theȱnextȱstep.ȱTheȱsequenceȱshownȱinȱFig.ȱ4ȱrepresentsȱtheȱ majorȱcomponentsȱofȱtheȱsequentialȱdevelopmentȱmodel.ȱ Inȱ thisȱ model,ȱ theȱ processȱ isȱ dividedȱ intoȱ threeȱ sections,ȱ theȱ firstȱ one,ȱ whichȱ canȱ beȱ calledȱ systemȱ identification,ȱ includesȱ theȱ userȱ requirements,ȱ theȱ systemȱ requirementsȱ andȱ theȱ architecturalȱ design.ȱ Theȱ secondȱ section,ȱ whichȱ canȱ beȱ calledȱ systemȱ creation,ȱ includesȱ theȱ componentȱ developmentȱandȱtheȱsystemȱassemblyȱprocess.ȱTheȱthirdȱ sectionȱ canȱ beȱ definedȱ asȱ verification,ȱ whichȱ includesȱ testingȱ ofȱ theȱ individualȱ componentsȱ andȱ theȱ wholeȱ system.ȱItȱisȱalsoȱbeȱpossibleȱtoȱsayȱthat,ȱtheȱfirstȱsectionȱisȱ officeȬbasedȱ work,ȱ theȱ secondȱ sectionȱ isȱ workshopȱ productionȱ andȱ theȱ thirdȱ sectionȱ isȱ laboratoryȱ work,ȱ whichȱ willȱ leadȱ theȱ productȱ toȱ theȱ operationalȱ environment.ȱ TheȱsequentialȱmodelȱcanȱbeȱoverlaidȱoverȱtheȱSEȱprocessȱ describedȱbyȱThomeȱ2001ȱtoȱcompareȱtheȱstepsȱinȱbothȱofȱ theȱ twoȱ conceptsȱ ofȱ developmentȱ –seeȱ Fig.ȱ 5.ȱ Theȱ mainȱ purposeȱofȱthisȱoverlayingȱisȱtoȱillustrateȱtheȱabilityȱofȱtheȱ sequentialȱ modelȱ forȱ tailoringȱ toȱ suitȱ theȱ systemȱ underȱ development.ȱ ȱ Review User Requirements

System Requirement

Change & Feedback

Review

Architectural Design

Change & Feedback

Component Development

Component delivery

Change & Feedback

Change & Feedback

ȱ 4.ȱSystemsȱEngineeringȱModelȱ ȱ 4.1ȱBackgroundȱ Aȱroboticȱsystemȱgenerallyȱcomprisesȱmanyȱmodulesȱthatȱ needȱ toȱ workȱ togetherȱ toȱ performȱ aȱ task.ȱ Theȱ requiredȱ capabilityȱrangeȱofȱrobotsȱforȱhazardousȱenvironmentsȱisȱ veryȱ wideȱ dependingȱ uponȱ factorsȱ suchȱ asȱ theȱ natureȱ ofȱ theȱ task,ȱ theȱ degreeȱ ofȱ structureȱ inȱ theȱ environmentȱ andȱ theȱ levelȱ ofȱ hazards.ȱ Theȱ developmentȱ ofȱ advancedȱ technologyȱ requiresȱ bothȱ aȱ studyȱ ofȱ economicȱ feasibilityȱ andȱ anȱ assessmentȱ ofȱ availableȱ technology.ȱ Theȱ identificationȱ ofȱ theȱ requiredȱ capabilitiesȱ thatȱ aȱ roboticȱ systemȱshouldȱhaveȱisȱnotȱanȱeasyȱtaskȱandȱitȱrequiresȱtheȱ useȱ ofȱ aȱ systematicȱ approachȱ thatȱ enablesȱ theȱ developerȱ toȱhaveȱconcreteȱinformation,ȱwhichȱcanȱhelpȱinȱsatisfyingȱ theȱ endȱ userȱ requirements.ȱ Theȱ adoptionȱ ofȱ aȱ systematicȱ approachȱinȱtheȱdevelopmentȱofȱanyȱsystemȱrequiresȱtheȱ useȱ ofȱ anȱ appropriateȱ developmentȱ model,ȱ whichȱ takesȱ intoȱ considerationȱ theȱ uniqueȱ natureȱ ofȱ theȱ particularȱ constructionȱtasks.ȱTheȱmanyȱmodulesȱofȱaȱroboticȱsystemȱ

Review

Integration &Verification Systems test

Change & Feedback

Installation &Validation

Change & Feedback

Operational Capability

Acceptance Test

ȱ

Fig.ȱ4ȱSEȱsimpleȱsequentialȱmodelȱ ȱ Objective

User Requirements

Concept

System Requirements

Technology Architectural Design

3.2ȱSummaryȱofȱtheȱmodelȱstepsȱ NeedȱAnalysis:ȱanalyseȱtheȱtask,ȱdefineȱtheȱenvironmentȱ variables,ȱ andȱ suggestȱ alternativesȱ withȱ simpleȱ demosȱ andȱselectionȱcriteriaȱforȱtheȱalternatives.ȱ DecisionȬmaking:ȱmeasureȱtheȱprioritiesȱofȱeachȱcriterionȱ withȱ respectȱ toȱ theȱ alternativesȱ andȱ produceȱ levelsȱ ofȱ preferenceȱ betweenȱ alternatives.ȱ Theȱ outputȱ couldȱ beȱ multipleȱfeasibleȱalternativesȱbasedȱonȱtheȱneedȱanalysisȱ Technologyȱ approval:ȱ aȱ selectionȱ procedureȱ forȱ theȱ appropriateȱtechnologyȱforȱeachȱalternativeȱ Economicȱ analysis:ȱ Aȱ detailedȱ costȱ analysisȱ andȱ costȱ comparisonȱofȱtheȱselectedȱtechnologyȱandȱtheȱtraditionalȱ methodsȱcostȱrepeatedȱforȱeachȱalternative.ȱ Implementationȱofȱtheȱfeasibleȱalternative(s)ȱ

Evaluation

Recommendation Development & Manufacturing

Component development Integration& Verification

Application

System 1

System 2

Operation

Time ȱ Fig.ȱ 5ȱ SEȱ sequentialȱ modelȱ overlaidȱ onȱ theȱ SEȱ processȱ diagramȱ

481


4.2ȱElementsȱofȱtheȱsequentialȱmodelȱ Theȱ tailoringȱ processȱ ofȱ aȱ developmentȱ modelȱ basedȱ onȱ theȱSEȱprocessȱneedsȱknowledgeȱofȱtheȱmainȱcomponentsȱ ofȱtheȱbasicȱsequentialȱmodel,ȱwhichȱasȱcanȱbeȱseenȱfromȱ Fig.ȱ5ȱrepresentsȱtheȱindividualȱstepsȱofȱtheȱSEȱprinciples.ȱ Inȱtheȱfollowingȱsectionȱdetailsȱofȱtheȱmainȱcomponentsȱofȱ theȱsequentialȱmodelȱareȱdiscussed.ȱ 4.2.1ȱTheȱuserȱrequirementsȱ Theȱ userȱ requirementsȱ areȱ theȱ firstȱ stepȱ inȱ theȱ developmentȱ processȱ andȱ theȱ finishedȱ productȱ shouldȱ satisfyȱ theseȱ requirements.ȱ Theȱ userȱ requirementsȱ driveȱ allȱ theȱ subsequentȱ stagesȱ ofȱ developmentȱ andȱ theyȱ alsoȱ tellȱusȱwhatȱwillȱdominateȱtheȱfutureȱfromȱanȱoperationalȱ pointȱ ofȱ viewȱ however,ȱ theyȱ doȱ notȱ specifyȱ howȱ theȱ objectivesȱareȱachieved.ȱȱ ȱ 4.2.2ȱTheȱsystemȱrequirementsȱ Itȱ isȱ anȱ intermediateȱ stepȱ betweenȱ theȱ userȱrequirementsȱ andȱ designȱ stageȱ aimingȱ toȱ showȱ whatȱ theȱ systemȱ isȱ goingȱ toȱ doȱ butȱ withoutȱ detailsȱ ofȱ howȱ itȱ willȱ beȱ done.ȱ Theȱ systemȱ requirementȱ shouldȱ beȱ writtenȱ inȱ aȱ detailedȱ documentȱ calledȱ systemȱ requirementsȱ documentȱ SRD.ȱȱ Theȱobjectivesȱofȱtheȱdocumentȱare:ȱȱ 1. Explainingȱtheȱwholeȱideaȱofȱtheȱsystemȱ 2. Exploring,ȱ optimisingȱ andȱ providingȱ alternativesȱȱ 3. Demonstratingȱtheȱreflectionȱofȱtheȱuserȱneedsȱ 4. Providingȱaȱbasisȱforȱtestingȱofȱtheȱfinalȱsystemȱ Theȱ systemȱ requirementsȱ shouldȱ satisfyȱ theȱ userȱ requirementsȱandȱtheyȱshouldȱbeȱfunctionalȱandȱneeded.ȱ Itȱ isȱ possibleȱ toȱ findȱ thatȱ oneȱ componentȱ ofȱ theȱ systemȱ requirementsȱ willȱ meetȱ multipleȱ userȱ requirements.ȱ Itȱ isȱ commonȱ toȱ findȱ thatȱ usersȱ judgeȱ theȱ finalȱ productȱ accordingȱ toȱ howȱ wellȱ theirȱ requirementsȱ areȱ satisfied,ȱ partiallyȱ metȱ orȱ evenȱ rejectedȱ byȱ theȱ product.ȱ Itȱ isȱ possibleȱ toȱ produceȱ aȱ goodȱ systemȱ requirementsȱ documentȱbyȱusingȱtheȱfollowingȱprinciples:ȱ 1. Removeȱ unnecessaryȱ designȱ decisionsȱ inȱ requirementsȱ 2. Summariseȱandȱlocaliseȱcriticalȱinterfacesȱ 3. Aimȱ toȱ useȱ commerciallyȱ availableȱ componentsȱ orȱreȬuseȱcomponentsȱwhereȱpossibleȱ 4. Allowȱgroupȱbrainstormingȱtechniquesȱ ȱ Theȱ definitionȱ ofȱ theȱ systemȱ requirementsȱ mustȱ beȱ followedȱ byȱ theȱ identificationȱ ofȱ theȱ nonȬfunctionalȱ requirementsȱorȱconstraints.ȱStevensȱetȱalȱ(1998)ȱidentifiedȱ thatȱ nonȬfunctionalȱ requirementsȱ addȱ nothingȱ toȱ theȱ systemȱfunctionsȱbutȱtheyȱprovideȱtheȱrequiredȱqualityȱofȱ theseȱ functions.ȱ Theȱ considerationȱ ofȱ constraintsȱ addsȱ extraȱcostȱtoȱtheȱsystemȱbutȱtheyȱmayȱaddȱmoreȱreliabilityȱ toȱtheȱsystemȱforȱexample.ȱConstraintsȱcanȱbeȱcategorisedȱ asȱ constraintsȱ transformedȱ fromȱ userȱ requirements,ȱ disciplineȱ specificȱ constraints,ȱ workingȱ environmentȱ constraintsȱ andȱ externalȱ systemsȱ constraints.ȱ Theseȱ constraintsȱ couldȱ varyȱ fromȱ oneȱ systemȱ toȱ another,ȱ andȱ forȱ eachȱ systemȱ theȱ nonȬfunctionalȱ requirementsȱ shouldȱ

482

beȱ identifiedȱ inȱ relationȱ toȱ theȱ systemȱ underȱ development.ȱHoweverȱ itȱ isȱ likelyȱ thatȱ informationȱ fromȱ otherȱsimilarȱsystemsȱwillȱbeȱused.ȱȱ 6.2.3ȱTheȱArchitecturalȱDesignȱ Theȱ systemȱ structureȱ definesȱ whatȱ areȱ theȱ majorȱ components,ȱ theirȱ arrangements,ȱ decompositionsȱ andȱ theirȱ interrelationships.ȱ Itȱ givesȱ logicalȱ definitionsȱ ofȱ theȱ components,ȱ whichȱ allowȱ theȱ designȱ toȱ beȱ doneȱ inȱ differentȱways.ȱTheȱsystemȱstructureȱdesignȱshouldȱadoptȱ theȱfollowingȱprinciples:ȱ 1. Startȱ withȱ aȱ simpleȱ designȱ toȱ meetȱ theȱ basicȱ requirementsȱandȱthenȱaddȱonȱextrasȱ 2. Minimiseȱcomponentȱcouplingȱȱ 3. Maximiseȱcohesionȱofȱsimilarȱcomponentsȱȱ 4. UseȱoffȬtheȬshelfȱcomponentsȱȱ ȱ Theȱ systemȱ behaviourȱ modelȱ enablesȱ usȱ toȱ viewȱ theȱ dynamicsȱ ofȱ theȱ systemȱ withoutȱ goingȱ intoȱ theȱ designȱ details.ȱ Threeȱ characteristicsȱ canȱ beȱ extractedȱ fromȱ theȱ behaviourȱmodel:ȱ ȱ 1. Richȱ abstractionȱ forȱ interaction:ȱ simpleȱ linesȱ connectingȱ theȱ architectureȱ componentsȱ canȱ simulateȱ theȱ componentȱ interactionȱ butȱ theseȱ linesȱcontainȱcomplexȱprotocolsȱȱ 2. Globalȱ properties:ȱ inȱ theȱ architecturalȱ designȱ stageȱ theȱ systemȱ behaviourȱ canȱ beȱ identifiedȱ inȱ caseȱofȱcomponentȱfailureȱandȱmodificationȱalsoȱ theȱ standardizationȱ ofȱ componentsȱ e.g.ȱ theȱ dataȱ flowȱinȱtheȱsystem.ȱ 3. ȱEmergentȱ properties:ȱ theȱ effectȱ onȱ overallȱ systemȱ behaviourȱ ofȱ addingȱ individualȱ components.ȱ ȱ Theȱ systemȱ layoutȱ linksȱ theȱ componentsȱ andȱ indicatesȱ physicalȱplacement,ȱcharacteristicsȱandȱcoreȱtechnology.ȱȱ Theȱarchitectureȱdesignȱcanȱbeȱimprovedȱbyȱtheȱfollowingȱ ways:ȱ 1. ReȬuseȱofȱpreȬexistingȱcomponentsȱtoȱreduceȱtheȱ costȱandȱtimeȱofȱdevelopmentȱ 2. ReȬusingȱtheȱsameȱcomponentȱseveralȱtimesȱ 3. Producingȱcomponentsȱthatȱcanȱbeȱusedȱinȱotherȱ systemsȱ ȱ ToȱsupportȱtheȱreȬuseȱpolicyȱinȱtheȱarchitectureȱdesignȱtheȱ followingȱshouldȱbeȱconsideredȱ 1. TheȱuseȱofȱcommercialȱoffȬtheȬshelfȱcomponentsȱ 2. Decoupling:ȱ a. Eachȱ individualȱ componentȱ mustȱ beȱ independentȱofȱotherȱcomponentsȱ b. Clearȱ interfacesȱ andȱ behaviourȱ ofȱ theȱ componentȱ toȱ allowȱ theȱ reȬuseȱ ofȱ theȱ componentȱinȱdifferentȱplacesȱ c. Althoughȱ theȱ componentȱ isȱ independentȱ inȱ itsȱ designȱ butȱ itȱ mustȱ beȱ ableȱ toȱ interactȱ withȱotherȱcomponentsȱ


4.2.4ȱTheȱarchitecturalȱdesignȱdocumentȱ(ADD)ȱ Theȱ ADDȱ includesȱ allȱ theȱ informationȱ aboutȱ theȱ componentsȱ inȱ theȱ systemȱ architecture.ȱ Theȱ informationȱ includesȱaȱdataȱsheetȱforȱeachȱcomponentȱindicating:ȱ 1. Componentȱbehaviourȱ 2. Componentȱfunctionalityȱ 3. Componentȱinterfacesȱ 4. Componentȱlayoutȱ 5. Dependencyȱ&ȱrequiredȱresourcesȱ 6. Testȱcriteriaȱ ȱ Inȱ additionȱ toȱ theȱ aboveȱ dataȱ sheets,ȱ theȱ ADDȱ containsȱ theȱ documentȱ status,ȱ descriptionȱ ofȱ theȱ components,ȱ interactionȱ withȱ theȱ environmentȱ andȱ aȱ definitionȱ ofȱ theȱ decompositionȱ method.ȱ Theȱ documentȱ alsoȱ includesȱ theȱ degreeȱ ofȱ fulfilmentȱ ofȱ theȱ systemȱ requirementsȱ andȱ theȱ userȱrequirementsȱwhenȱusingȱtheȱcurrentȱdesign.ȱ ȱ 4.2.4ȱComponentȱdevelopmentȱȱ Theȱ architecturalȱ designȱ documentȱ includesȱ theȱ detailedȱ designȱofȱtheȱindividualȱmodulesȱofȱtheȱsystemȱincluding,ȱ functionalities,ȱ interfacesȱ andȱ layouts.ȱ Theȱ givenȱ informationȱ isȱ enoughȱ toȱ manufactureȱ theȱ systemȱ componentsȱorȱtoȱpurchaseȱoffȬtheȬshelfȱcomponents.ȱTheȱ developmentȱ processȱ ofȱ theȱ componentsȱ isȱ followedȱ byȱ anȱ importantȱ procedureȱ forȱ componentsȱ testing,ȱ assemblingȱandȱfinalȱacceptanceȱ ȱ 4.2.5ȱIntegration,ȱverificationȱandȱoperationȱ Verificationȱ canȱ beȱ performedȱ inȱ twoȱ stages.ȱ Theȱ firstȱ stageȱisȱdesignȱverificationȱinȱwhichȱtheȱdesignȱisȱcertifiedȱ againstȱtheȱrequirementsȱandȱitȱassuresȱthatȱtheȱproductȱisȱ goingȱ toȱ workȱ properlyȱ ifȱ itȱ isȱ manufacturedȱ correctly.ȱ Theȱsecondȱstageȱisȱtheȱproductionȱverification,ȱwhereȱtheȱ systemȱisȱtestedȱforȱmanufacturingȱfaults.ȱTheȱverificationȱ processȱ canȱ beȱ performedȱ onȱ aȱ unitȬbyȬunitȱ basisȱ forȱ aȱ smallȱsystemȱproductionȱorȱbyȱtestingȱselectedȱunitsȱinȱaȱ massȱ productionȱ system.ȱ Theȱ verificationȱ processȱ canȱ beȱ performedȱatȱdifferentȱlevelsȱofȱtheȱsystemȱdevelopment,ȱ i.e.ȱ verificationȱ ofȱ aȱ component,ȱ verificationȱ ofȱ subȱ assemblies,ȱ verificationȱ ofȱ assembliesȱ andȱ verificationȱ ofȱ theȱ wholeȱ system.ȱ Theȱ verificationȱ processȱ ofȱ aȱ systemȱ canȱbeȱdoneȱinȱtheȱfollowingȱlevels:ȱ 1. Theȱ lowestȱ orȱ theȱ firstȱ levelȱ ofȱ verification,ȱ whichȱ isȱ theȱ bestȱ wayȱ ofȱ assuringȱ theȱ systemȱ operation,ȱ isȱ theȱ componentȱ level,ȱ whichȱ isȱ verifiedȱbyȱcomponentȱtesting.ȱ 2. Theȱ secondȱ levelȱ isȱ theȱ architecturalȱ design,ȱ whichȱisȱtestedȱbyȱtheȱintegrationȱtest.ȱȱ 3. Theȱ thirdȱ levelȱ isȱ theȱ systemȱ testȱ whichȱ verifiesȱ theȱsystemȱrequirementsȱ ȱ Successȱ ofȱ theȱ verificationȱ processȱ canȱ beȱ guaranteedȱ ifȱ youȱfollowȱtheȱfollowingȱrulesȱasȱidentifiedȱbyȱStevensȱetȱ alȱ(1998):ȱ a. Verifyȱatȱtheȱlowestȱlevelȱ b. Verifyȱasȱearlyȱasȱpossibleȱ

c. d. e. f. g. h.

Useȱtalentedȱpeopleȱforȱverificationȱ Testȱtheȱrealȱproductȱ Inspectȱ theȱ systemȱ toȱ identifyȱ theȱ requiredȱ testsȱ Ensureȱ thatȱ theȱ designȱ isȱ testableȱ byȱ imposingȱdesignȱrequirementsȱonȱitȱ Verifyȱ testȱ andȱ simulationȱ toolsȱ withȱ theȱ sameȱrigorȱasȱtheȱdeliverableȱitemsȱ Verifyȱ theȱ procedureȱ thatȱ willȱ handleȱ testȱ failuresȱ

ȱ Onȱ finishingȱ theȱ verificationȱ process,ȱ theȱ systemȱ canȱ beȱ movedȱfromȱtheȱtestingȱenvironmentȱtoȱtheȱfinalȱstageȱofȱ installationȱ andȱ validationȱ orȱ toȱ theȱ operationalȱ environment.ȱ Inȱ theȱ operationalȱ environmentȱ theȱ systemȱ shouldȱ passȱ twoȱ levelsȱ ofȱ acceptances,ȱ theȱ provisionalȱ acceptanceȱ andȱ theȱ finalȱ acceptance.ȱ Theȱ provisionalȱ acceptanceȱ meansȱ thatȱ theȱ systemȱ meetsȱ itsȱ systemȱ andȱ userȱ requirementsȱ inȱ theȱ realȱ operationalȱ environmentȱ underȱ theȱ testȱ conditions,ȱ whileȱ theȱ finalȱ acceptanceȱ meansȱthatȱtheȱcustomerȱagreesȱthatȱtheȱsystemȱmeetsȱitsȱ userȱrequirementsȱinȱtheȱactualȱoperationalȱenvironment.ȱȱ ȱ 5ȱ Theȱ useȱ ofȱ aȱ partiallyȱ developedȱ systemȱ inȱ aȱ newȱ systemȱ Theȱsystemsȱengineeringȱprocessȱisȱdesignedȱtoȱcopeȱwithȱ complexȱ systems,ȱ partȱ ofȱ thisȱ complexityȱ canȱ comeȱ fromȱ theȱ useȱ ofȱ partiallyȱ developedȱ systems.ȱ Theȱ partiallyȱ developedȱsystemȱcanȱbeȱdocumentedȱandȱreȬengineeredȱ forȱ furtherȱ developmentȱ inȱ termsȱ ofȱ theȱ systemsȱ engineeringȱ principles.ȱ Fig.ȱ 6ȱ showsȱ theȱ implementationȱ ofȱaȱpartiallyȱdevelopedȱsystemȱinȱdifferentȱstagesȱofȱtheȱ developmentȱprocess.ȱ Itȱ isȱ necessaryȱ toȱ performȱ aȱ completeȱ analysisȱ ofȱ theȱ partiallyȱ developmentȱ systemȱ andȱ identifyȱ theȱ systemȱ functions,ȱ systemȱ architectureȱ andȱ theȱ systemȱ components.ȱTheȱoutputȱfromȱthisȱanalysisȱisȱaȱdocumentȱ thatȱ describesȱ theȱ systemȱ objectivesȱ andȱ componentȱ functionality.ȱ Itȱ isȱ possibleȱ toȱ recallȱ theȱ formatȱ ofȱ theȱ architecturalȱ designȱ documentȱ hereinȱ asȱ aȱ modelȱ forȱ theȱ outputȱ fromȱ theȱ partiallyȱ developedȱ systemȱ analysisȱ inȱ termsȱof:ȱ 1. Componentȱbehaviourȱ 2. Componentȱfunctionalityȱ 3. Componentȱinterfacesȱ 4. Componentȱlayoutȱ 5. Dependencyȱ&ȱrequiredȱresourcesȱ 6. Testȱcriteriaȱ ȱ Theȱpartiallyȱdevelopedȱsystemȱdocumentȱcanȱthenȱbeȱfedȱ intoȱ toȱ theȱ systemȱ engineeringȱ process.ȱ Alreadyȱ developedȱ componentsȱ couldȱ beȱ modifiedȱ orȱ integratedȱ withȱ theȱ systemȱ accordingȱ toȱ theȱ requirementsȱ ofȱ theȱ architecturalȱ andȱ theȱ detailedȱ designs.ȱ Afterwardȱ theȱ processȱ ofȱ theȱ developmentȱ returnsȱ toȱ theȱ normalȱ stepsȱ forȱ integrationȱ andȱ verificationȱ upȱ toȱ theȱ finalȱ operationȱ step.ȱ Theȱ evolutionaryȱ developmentȱ modelȱ enablesȱ theȱ

483


8.

stagedȱ implementationȱ ofȱ partiallyȱ developedȱ systemsȱ accordingȱtoȱtheȱneedsȱofȱtheȱdevelopmentȱcycle.ȱI.e.ȱpartȱ ofȱtheȱsystemȱcanȱbeȱimplementedȱinȱtheȱfirstȱcycleȱasȱfarȱ asȱanȱoperationalȱsystem,ȱandȱthenȱtheȱotherȱpartȱmayȱbeȱ implementedȱlaterȱtoȱsuiteȱtheȱnextȱstageȱofȱdevelopmentȱ andȱeconomicȱfeasibility.ȱ ȱ ȱ

9.

Partially Developed System Documentation System Functions Review User Requirements

System Requirement

System Modules

Component Delivery

Review/modify Architectural Design

Implement

Review Component Development

Component delivery Integration &Verification Systems test

Change & Feedback

Change & Feedback

Change & Feedback

Installation &Validation

Change & Feedback

Acceptance Test Operational Capability

Fig.ȱ6ȱimplementationȱofȱpartiallyȱdevelopedȱsystemȱintoȱ aȱnewȱsystemȱ ȱ 6.ȱStarlifterȱdevelopmentȱprocessȱȱ Theȱ SEȱ developmentȱ processȱ describedȱ inȱ sectionȱ 4ȱ isȱ employedȱtoȱdevelopȱtheȱStarlifterȱroboticȱsystem.ȱAsȱtheȱ needȱ analysisȱ andȱ theȱ feasibilityȱ analysisȱ isȱ basedȱ onȱ theȱ useȱ ofȱ Starlifterȱ inȱ concreteȱ drillingȱ andȱ concreteȱ sawingȱ process,ȱtheȱstartingȱpointȱwasȱtoȱgatherȱinformationȱfromȱ theȱ endȱ usersȱ asȱ indicatedȱ inȱ theȱ userȱ requirements.ȱ Theȱ followingȱ sectionsȱ showȱ theȱ procedureȱ usedȱ inȱ implementingȱtheȱdevelopmentȱmodel.ȱ

ȱ

ȱ Theȱsiteȱandȱsafetyȱengineersȱraiseȱtheȱfollowingȱissues:ȱ 1. Markingȱ theȱ workingȱ areaȱ forȱ drillingȱ andȱ concreteȱ sawingȱ shouldȱ beȱ doneȱ andȱ approvedȱ priorȱtoȱtheȱactualȱoperation.ȱ 2. Theȱ supportingȱ equipmentȱ suchȱ asȱ powerȱ source,ȱwaterȱsourceȱforȱdrillingȱandȱsawingȱandȱ theȱwasteȱremovalȱtruckȱshouldȱbeȱprovidedȱonȱ schedule.ȱ 3. Theȱ hazardsȱ involvedȱ inȱ theȱ systemȱ shouldȱ beȱ identifiedȱ andȱ aȱ riskȱ assessmentȱ shouldȱ beȱ preparedȱpriorȱtoȱimplementation.ȱ 4. Surveillanceȱ camerasȱ areȱ neededȱ forȱ operationȱ andȱsiteȱsupervisionȱȱ ȱ Theȱ workersȱ provideȱ theȱ followingȱ informationȱ forȱ traditionalȱmethods:ȱ 1. Theȱcuttingȱtoleranceȱshouldȱbeȱwithinȱ r 2 ȱmmȱ 2.

3. 4.

ȱ 6.1ȱTheȱuserȱrequirementsȱȱ Inȱ theȱ currentȱ scenarioȱ theȱ clientȱ (theȱ contractorȱ whoȱ wishesȱ toȱ introduceȱ theȱ newȱ technology)ȱ raisesȱ theȱ followingȱissues:ȱ 1. Theȱ siteȱ isȱ contaminatedȱ withȱ leadȱ becauseȱ itȱ wasȱ aȱ storeȱ forȱ batteries,ȱ whichȱ requiresȱ theȱ avoidanceȱofȱdirectȱhumanȱintervention.ȱ 2. Theȱ holesȱ shouldȱ beȱ drilledȱ asȱ quicklyȱ asȱ possibleȱwithȱreasonableȱaccuracyȱusingȱexistingȱ diamondȱ coreȱ drillsȱ andȱ otherȱ supportingȱ equipment.ȱ 3. Existingȱ plungeȱ sawsȱ shouldȱ beȱ usedȱ toȱ accomplishȱ theȱ cuttingȱ processȱ withinȱ aȱ minimumȱtime.ȱ 4. Accessȱconstraintsȱtoȱtheȱinteriorȱofȱtheȱbuildingȱ exist.ȱ 5. Theȱ finishedȱ productȱ usingȱ theȱ newȱ systemȱ shouldȱbeȱwithinȱstandardȱtolerancesȱ 6. Theȱcostȱofȱtheȱnewȱsystemȱshouldȱbeȱwithinȱtheȱ agreedȱlimit.ȱȱ 7. Forȱ theȱ newȱ systemȱ aȱ userȱ interfaceȱ shouldȱ beȱ providedȱ withȱ allȱ theȱ requiredȱ informationȱ concerningȱoperation,ȱsafetyȱandȱschedule.ȱ

484

Theȱsystemȱshouldȱcomplyȱwithȱallȱstandardsȱofȱ operationȱandȱcodesȱofȱpracticeȱinȱthisȱfield.ȱ ȱAȱ compatibleȱ offȬlineȱ systemȱ forȱ taskȱ simulation,ȱ planning,ȱ scheduling,ȱ costingȱ andȱ reportȱgenerationȱisȱrequired.ȱ

5. 6.

Forȱ aȱ squareȱ opening,ȱ theȱ numberȱ ofȱ holesȱ requiredȱtoȱinsertȱtheȱplungeȱsawȱisȱproportionalȱ toȱ theȱ sizeȱ ofȱ theȱ openingȱ andȱ theȱ sizeȱ ofȱ theȱ sawingȱblade.ȱForȱexample,ȱforȱaȱsquareȱopeningȱ ofȱ1ȱmȱinȱsideȱlengthȱandȱaȱ30ȱcmȱdepthȱoneȱholeȱ inȱ eachȱ sideȱ centreȱ canȱ beȱ usedȱ withȱ aȱ bladeȱ diameterȱofȱ1ȱm.ȱ Anchorsȱshouldȱbeȱattachedȱtoȱholdȱandȱsupportȱ theȱremovedȱconcreteȱblockȱ Theȱ drillingȱ andȱ sawingȱ feedȱ couldȱ beȱ doneȱ manuallyȱorȱautomaticallyȱ Disposableȱ protectionȱ suitsȱ shouldȱ beȱ usedȱ whenȱworkingȱinȱaȱcontaminatedȱsiteȱ Standardȱ protectionȱ equipmentȱ isȱ usedȱ whenȱ usingȱtheȱdrillingȱandȱsawingȱrigs.ȱ

ȱ 6.2ȱSystemȱrequirementsȱ Theȱ userȱ requirementsȱ captureȱ processȱ providedȱ informationȱ regardingȱ theȱ operationalȱ environmentȱ asȱ mentionedȱaboveȱtheȱmanagementȱdecidedȱtoȱuseȱroboticȱ technologyȱ toȱ avoidȱ theȱ risksȱ involvedȱ fromȱ theȱ safetyȱ pointȱ ofȱview.ȱItȱ isȱ nowȱ possibleȱ toȱ identifyȱ theȱ requiredȱ systemȱcapabilitiesȱinȱtermsȱofȱtheȱuserȱrequirements.ȱTheȱ userȱ requirementsȱ canȱ beȱ translatedȱ intoȱ systemȱ requirements,ȱwhichȱcanȱbeȱdefinedȱinȱtermsȱofȱdifferentȱ functions.ȱ Theȱ mainȱ systemȱ isȱ dividedȱ intoȱ twoȱ subsystems,ȱtheȱfirstȱisȱtheȱoffȬlineȱsystemȱandȱtheȱsecondȱisȱ theȱonȬboardȱsystem.ȱȱ TheȱmainȱfunctionsȱofȱtheȱoffȬlineȱsystemȱare:ȱ a. Receivingȱtheȱcontractȱinformationȱ b. Creatingȱ simulationsȱ forȱ theȱ systemȱ componentsȱandȱtheȱworkingȱsiteȱ c. Identifyingȱtasksȱ d. Planningȱtasksȱȱ


e. f. g. h. i. j. k.

Preparingȱtaskȱschedulesȱ Evaluatingȱtheȱcontractȱcostsȱ Generatingȱ aȱ descriptiveȱ reportȱ forȱ theȱ wholeȱcontractȱincludingȱpricesȱ Reviewingȱtheȱresourcesȱrequiredȱ Reviewingȱ safetyȱ issues,ȱ codesȱ ofȱ practiceȱ andȱregulationsȱ Arrangingȱforȱtoolsȱandȱlogisticsȱdispatchȱ Issuingȱworkingȱordersȱ

ȱ Theȱ onȬboardȱ systemȱ functionȱ isȱ mainlyȱ dividedȱ intoȱ sixȱ functions;ȱtheseȱfunctionsȱcollaborateȱtoȱperformȱtheȱmainȱ function.ȱ Thereȱ areȱ interdependenciesȱ betweenȱ theȱ systemsȱinvolvedȱinȱdoingȱtheseȱseparateȱfunctions.ȱTheseȱ functionsȱcanȱbeȱdecomposedȱasȱfollows:ȱ ȱ

1.

2.

3.

ȱ 4.

5.

6.

Handlingȱ inputȱ andȱ outputȱ fromȱ andȱ withinȱ theȱ systemȱȱ a. Receivingȱworkȱissuesȱandȱtaskȱdetailsȱfromȱ theȱoffȬlineȱsystem.ȱ b. Sendingȱ andȱ receivingȱ informationȱ fromȱ andȱtoȱdifferentȱcomponentsȱofȱtheȱsystem.ȱ c. Monitoringȱ theȱ performanceȱ ofȱ theȱ individualȱsystemȱcomponentsȱandȱassuringȱ harmony.ȱ d. Taskȱmonitoringȱandȱtaskȱsequenceȱcontrolȱ ȱ Handlingȱplatformȱpositionȱ a. Selectingȱtheȱplatformȱ b. Movingȱtheȱplatformȱtoȱaȱdesiredȱpositionȱ c. Providingȱaȱstableȱpositionȱforȱtheȱplatformȱ d. Handlingȱotherȱlogisticsȱ e. Interactingȱwithȱotherȱfunctionsȱ ȱ Handlingȱenvironmentȱinformationȱ a. Monitoringȱtheȱworkingȱareaȱ b. Checkingȱforȱcollisionsȱinȱtheȱworkingȱareaȱ c. Perceivingȱrelativeȱpositionȱandȱorientationsȱ w.ȱr.ȱtȱtheȱworkingȱareaȱ d. Issuingȱsafetyȱwarningsȱ e. Interactingȱwithȱotherȱfunctionsȱ Handlingȱmotionȱ a. Receivingȱpositionȱinformationȱ b. Sendingȱsignalsȱforȱpositionȱmodificationȱ c. Rectifyingȱpositionȱȱ d. Pathȱplanningȱȱ e. Interactingȱwithȱotherȱfunctionsȱ HandleȱendȬeffectorȱpositionȱ a. Receivingȱcommandsȱȱ b. Handlingȱtoolsȱ c. Providingȱaȱstableȱplatformȱforȱtoolsȱ d. Providingȱresourcesȱforȱotherȱfunctionsȱ e. Providingȱdesiredȱconfigurationsȱ f. Interactingȱwithȱotherȱfunctionsȱ Handlingȱtoolsȱ a. Providingȱmultipleȱtoolȱdocksȱ b. ProvidingȱStableȱplatformȱforȱtoolsȱȱ

c.

Providingȱ easyȱ engagementȱ disengagementsȱofȱtoolsȱ Sendingȱtoolȱstatusȱȱ

andȱ

d. ȱ Aȱfunctionalȱdecompositionȱdiagram,ȱwhichȱincludesȱtheȱ requiredȱ systemȱ componentsȱ thatȱ satisfyȱ theȱ userȱ requirements,ȱ shouldȱ beȱ preparedȱ alongsideȱ aȱ scenarioȱ forȱ theȱ proposedȱ task.ȱ Theȱ functionalȱ decompositionȱ diagramȱ andȱ theȱ systemȱ scenarioȱ illustrateȱ theȱ interrelationshipȱbetweenȱtheȱsystemȱunderȱdevelopmentȱ andȱ externalȱ systemsȱ suchȱ asȱ siteȱ management,ȱ facilitiesȱ etc.ȱȱ ȱ 6.3ȱArchitecturalȱdesignȱȱ Theȱ architectureȱ designȱ conceptsȱ canȱ beȱ representedȱ inȱ threeȱforms,ȱallȱofȱwhichȱgiveȱincreasedȱunderstandingȱofȱ theȱ systemȱ underȱ development.ȱ Theȱ threeȱ formsȱ are:ȱ theȱ systemȱ structure,ȱ theȱ systemȱ behaviourȱ andȱ theȱ systemȱ layout.ȱAsȱmentionedȱbefore,ȱtheȱsystemȱstructureȱdefinesȱ theȱ majorȱ componentȱ organizationȱ andȱ decomposition.ȱ Theȱ systemȱ behaviourȱ definesȱ theȱ inherentȱ dynamicsȱ inȱ theȱsystemȱandȱshowsȱhowȱtheȱsystemȱwillȱbehaveȱduringȱ operation.ȱ Finallyȱ theȱ systemȱ layoutȱ definesȱ theȱ physicalȱ interrelationshipȱbetweenȱtheȱsystemȱcomponentsȱasȱwellȱ asȱtheȱrelativeȱpositionȱofȱtheȱcomponents.ȱ ȱ 6.3.1ȱSystemȱstructureȱ Forȱ aȱ roboticȱ systemȱ itȱ isȱ possibleȱ toȱ defineȱ theȱ majorȱ componentsȱ basedȱ onȱ theȱ functionalȱ decompositionȱ presentedȱ inȱ theȱ systemȱ requirements.ȱ Itȱ isȱ howeverȱ difficultȱtoȱmakeȱaȱrelativeȱstructuralȱdecompositionȱorȱaȱ hierarchyȱ ofȱ theȱ majorȱ componentsȱ becauseȱ allȱ ofȱ themȱ areȱ distinctiveȱ andȱ cannotȱ beȱ subsystemsȱ ofȱ eachȱ other.ȱ Theȱdecompositionȱofȱeachȱcomponentȱcanȱbeȱdoneȱbasedȱ onȱtheȱsubȬfunctionsȱinvolvedȱinȱtheȱmainȱfunctionȱofȱtheȱ component.ȱ Fig.ȱ 7ȱ showsȱ theȱ majorȱ componentsȱ ofȱ theȱ Starlifterȱroboticȱsystemȱstructure.ȱTheȱmajorȱcomponentsȱ areȱ offȬlineȱ simulationȱ module,ȱ theȱ userȱ interface,ȱ theȱ controllerȱ module,ȱ theȱ sensingȱ module,ȱ theȱ manipulatorȱ &ȱendȬeffectorȱmoduleȱandȱtheȱtoolȬchangingȱmodule.ȱȱ ȱ Starlifter Robotic system

Controller Module

Manipulator & Endeffector

Mobility Module

Tool-changing Module

The User Interface

Sensing Module Off-line Simulation Module

ȱ Fig.ȱ7ȱTheȱroboticȱsystemȱstructureȱ ȱ 6.3.2ȱSystemȱbehaviourȱ Theȱsystemȱbehaviourȱcanȱbeȱidentifiedȱatȱtheȱtopȱlevelȱasȱ describedȱ inȱ theȱ operationalȱ scenario.ȱ Theȱ systemȱ behaviourȱmodelȱshownȱinȱFig.ȱ8ȱillustratesȱtheȱtopȬlevelȱ

485


behaviourȱofȱtheȱmajorȱcomponentsȱofȱtheȱsystem.ȱClearerȱ systemȱ behavioursȱ mayȱ beȱ illustratedȱ byȱ lowerȱ levelȱ subsystems,ȱ forȱ example,ȱ communicationȱ behaviourȱ inȱ theȱ controllerȱ module,ȱ whereȱ dataȱ isȱ exchangedȱ withinȱ theȱsubsystemȱitselfȱasȱwellȱasȱbetweenȱotherȱsubsystemsȱ inȱ theȱ architecture.ȱ Fig.ȱ 9ȱ showsȱ aȱ behaviouralȱ modelȱ ofȱ theȱcontrollerȱmodule.ȱȱ

Working Environment

Manipulator Module

Tool-changing module Laser Scanner Sensing Module

ȱ

Controller Module

Receive contract information

Plan & schedule tasks

GUI LabVIEW

Issue work orders

Other Constraints

On-board system Send/receive data & monitor tasks

Handle I/O Move/position tools & sensors

Handle endeffector position

Attach/detach tools

Handle tools Receive position, plan motion & send commands

Handle motion Determine current position, monitor task, issue safety warnings

Position robot base near the working area

Handle platform position

Handle environment information

System Transportation

Site Management

Facilities

ȱ Fig.ȱ 8ȱ Starlifterȱ roboticȱ systemȱ topȱ levelȱ behaviouralȱ modelȱ ȱ Sensing module Joints position High-level Controller

The User Interface

Mobility Module Evaluate involved cost

Provide site/system simulations

Generate a report

The user Interface

GS Workspace

Handle Contract

Off-line system

Supporting equipment

Vision/Ultrasonic Sensory System

Low-level Controller

ȱ Fig.ȱ10ȱStarlifterȱroboticȱsystemȱonȬboardȱlayoutȱ ȱ ȱ 6.4ȱTheȱroleȱofȱtheȱgraphicalȱsimulationȱprocessȱ Theȱ graphicalȱ simulationȱ processȱ ofȱ robotsȱ facilitatesȱ aȱ fastȱ andȱ accurateȱ validationȱ ofȱ theȱ resultingȱ motion.ȱ Theȱ graphicalȱ simulationȱ processȱ isȱ usedȱ extensivelyȱ inȱ industryȱtoȱexamineȱrobotȱprogramsȱbeforeȱdownloadingȱ toȱ theȱ actualȱ robots.ȱ Theȱ useȱ ofȱ thisȱ methodȱ reducesȱ theȱ standstillȱtimeȱandȱincreasesȱproductivity.ȱTheȱsimulationȱ toolsȱ areȱ usedȱ toȱ aidȱ theȱ choiceȱ ofȱ manipulatorȱ configurationȱ andȱ toȱ testȱ theȱ usefulnessȱ ofȱ theȱ robotȱ byȱ virtualȱscenarios.ȱ Inȱ theȱ presentȱ work,ȱ Workspaceȱ robotȱ simulationȱ packageȱisȱusedȱinȱtheȱsimulationȱofȱrobot,ȱtoolsȱandȱtheȱ workingȱ environmentȱ seeȱ Fig.ȱ 11.ȱ Theȱ graphicalȱ simulationȱprocessȱofȱaȱrobotȱmainlyȱdependsȱonȱtheȱDȬHȱ parameters,ȱ DanivetȬHartenbergȱ (1955),ȱ whichȱ canȱ beȱ derivedȱ byȱ constructingȱ aȱ kinematicalȱ diagramȱ ofȱ theȱ robot.ȱ ȱ

ȱ

Manipulator Module

Tool-changing module

ȱ Fig.ȱ 9ȱ Topȱ levelȱ behaviouralȱ modelȱ forȱ theȱ controllerȱ moduleȱ ȱ 6.3.3ȱSystemȱlayoutȱ Theȱ topȱ layoutȱ ofȱ theȱ systemȱ isȱ aȱ directȱ interpretationȱ ofȱ theȱphysicalȱcomponentȱarrangement.ȱTheseȱcomponentsȱ areȱ performingȱ theȱ mainȱ functionsȱ illustratedȱ inȱ theȱ functionalȱdecompositionȱdiagramȱandȱtheirȱbehaviourȱisȱ illustratedȱ inȱ theȱ behaviouralȱ model.ȱ Theȱ onȬboardȱ systemȱlayoutȱisȱshownȱinȱFig.ȱ10ȱȱ Theȱ layoutȱ diagramȱ showsȱ someȱ detailsȱ ofȱ theȱ finalȱ workingȱ systemȱ butȱ theȱ designȱ detailsȱ orȱ typesȱ ofȱ interfacesȱareȱnotȱspecified.ȱTheȱmajorȱcomponentsȱinȱtheȱ aboveȱlayoutȱareȱtheȱsixȱmodulesȱalreadyȱidentifiedȱinȱtheȱ behaviouralȱ moduleȱ butȱ withȱ someȱ emphasisȱ onȱ theȱ componentsȱ usedȱ inȱ theȱ design.ȱ Theȱ selectionȱ ofȱ theȱ aboveȱcoreȱtechnologiesȱforȱthisȱapplicationȱisȱnotȱanȱeasyȱ task.ȱ Forȱ researchȱ purposesȱ itȱ isȱ necessaryȱ toȱ investigateȱ theȱ newȱ technologyȱ andȱ toȱ assessȱ theȱ suitabilityȱ ofȱ thisȱ technologyȱforȱconstructionȱapplications.ȱȱ

486

ȱ Fig.ȱ11ȱSimulationȱofȱtheȱStarlifterȱrobotȱ ȱ Theȱ simulationȱ processȱ playsȱ aȱ majorȱ roleȱ inȱ Starlifterȱ development.ȱ Theȱ simulationȱ processȱ isȱ usedȱ inȱ theȱ followingȱareas:ȱ 1. Systemȱdesignȱ 2. Motionȱplanningȱ 3. Environmentȱmodellingȱ 4. Taskȱmonitoringȱ 5. Costȱestimation.ȱȱ 6. OffȬlineȱprogrammingȱ


6.4.1ȱSystemȱdesignȱ Theȱ designȱ processȱ includesȱ testingȱ theȱ adaptabilityȱ ofȱ offȬtheȬshelfȱ componentsȱ andȱ exploringȱ possibleȱ modificationsȱ toȱ existingȱ componentsȱ toȱ suitȱ theȱ systemȱ underȱ development.ȱ Theȱ followingȱ componentsȱ areȱ presentedȱ asȱ examplesȱ ofȱ theȱ useȱ ofȱ simulationȱ inȱ theȱ designȱprocess.ȱ ȱ 6.4.1.1ȱAutomaticȱtoolȱchangerȱ Asȱanȱessentialȱpartȱofȱtheȱroboticȱprocess,ȱtheȱautomaticȱ toolȱ changerȱ isȱ availableȱ asȱ anȱ offȬtheȬshelfȱ componentȱ withȱdifferentȱsizesȱtoȱsuitȱdifferentȱtools.ȱTheȱactualȱtoolȱ changerȱdockȱconsistsȱofȱtwoȱhalves,ȱoneȱonȱtheȱtoolȱsideȱ andȱ theȱ otherȱ oneȱ onȱ theȱ toolȱ holderȱ side.ȱ Theȱ toolȱ changerȱ isȱ currentlyȱ pneumaticallyȱ operated.ȱ Itȱ isȱ intendedȱ toȱ changeȱ itȱ toȱ aȱ hydraulicallyȱ operatedȱ one,ȱ whichȱ isȱ consistentȱ withȱ theȱ robotȱ operationȱ powerȱ source.ȱ Thereȱ isȱ aȱ toolȱ holderȱ andȱ aȱ toolȱ dockȱ forȱ eachȱ tool,ȱinȱeachȱdockȱthereȱisȱaȱtoolȱgripper,ȱwhichȱholdsȱorȱ releasesȱtheȱtoolȱwheneverȱrequired.ȱInȱtheȱ designȱofȱtheȱ toolȱchangerȱtwoȱmainȱissuesȱareȱraised.ȱTheȱfirstȱissueȱisȱ theȱ toolsȱ arrangementȱ andȱ theȱ secondȱ issueȱ isȱ theȱ toolȱ holderȱmotion.ȱȱ Theȱ toolȱ arrangementȱ designȱ dependsȱ onȱ theȱ numberȱ ofȱ toolsȱandȱtheȱsequenceȱofȱtoolȱusage.ȱItȱisȱrequiredȱtoȱputȱ theȱtoolsȱinȱaȱconfinedȱspaceȱatȱtheȱrobotȱbaseȱtoȱeaseȱtheȱ motionȱofȱtheȱrobotȱbaseȱduringȱpositioningȱofȱtheȱrobot.ȱ Thereȱ areȱ twoȱ optionsȱ concerningȱ theȱ motionȱ designȱ ofȱ theȱtoolȱholder.ȱTheȱfirstȱoneȱisȱtoȱmoveȱtheȱendeffectorȱtoȱ aȱ knownȱ positionȱ ofȱ theȱ toolȱ holderȱ (Theȱ toolȱ holderȱ beingȱfixed.)ȱTheȱsecondȱoptionȱisȱtoȱmoveȱtheȱtoolȱholderȱ insideȱ theȱ workingȱ envelopeȱ ofȱ theȱ robotȱ wheneverȱ itȱ isȱ requiredȱtoȱchangeȱtheȱtool.ȱTheȱsecondȱoptionȱprovidesȱaȱ clearȱ workingȱ envelopeȱ duringȱ taskȱ performanceȱ howeverȱ aȱ collisionȱ withȱ theȱ armȱ couldȱ occurȱ ifȱ theȱ motionȱisȱnotȱaccuratelyȱplanned.ȱȱ ȱ 6.4.1.2ȱMobilityȱȱ Theȱmobilityȱmoduleȱisȱconcernedȱwithȱpositioningȱofȱtheȱ robotȱbaseȱinȱaȱrelativelyȱaccurateȱplaceȱnearȱtheȱworkingȱ area.ȱ Theȱ mobilityȱ moduleȱ shouldȱ provideȱ aȱ stableȱ platformȱforȱtheȱrobotȱduringȱtaskȱperformance.ȱȱ Theȱrequiredȱcapabilityȱofȱtheȱdeviceȱtoȱbeȱusedȱinȱrobotȱ positioningȱ dependsȱ onȱ theȱ workingȱ areaȱ characteristics.ȱ Forȱ example,ȱ workingȱ underneathȱ aȱ bridgeȱ orȱ inȱ highȱ placesȱ (freeȱ positioning)ȱ requiresȱ theȱ useȱ ofȱ aȱ telescopicȱ boom.ȱWhileȱworkingȱinsideȱrailȱtunnelsȱrequiresȱtheȱuseȱ ofȱspecialȱtruck.ȱTheȱsimulationȱprocessȱhelpsȱtheȱsystemȱ designerȱtoȱtryȱdifferentȱalternativesȱforȱtheȱproject.ȱȱ Anȱ exampleȱ forȱ aȱ mobilityȱ deviceȱ workingȱ insideȱ aȱ railȱ tunnelȱisȱtheȱSRSȱrail/roadȱtruckȱSRS,ȱ2002,ȱwhichȱcanȱbeȱ usedȱ asȱ aȱ mobilityȱ deviceȱ forȱ theȱ Starlifterȱ robotȱ whichȱ providesȱaȱstableȱplatformȱforȱtheȱrobotȱasȱwellȱasȱaȱsafeȱ platformȱ forȱ theȱ robotȱ operator.ȱ Itȱ isȱ designedȱ toȱ workȱ safelyȱ insideȱ activeȱ tunnelsȱ whileȱ otherȱ trainsȱ moveȱ alongside.ȱ Fig.ȱ 12ȱ showsȱ differentȱ viewsȱ ofȱ theȱ truckȱ

carryingȱ theȱ robot.ȱ Theȱ simulationȱ ofȱ theȱ truckȱ isȱ drawnȱ usingȱtheȱrealȱdimensions.ȱȱ

ȱ 6.4.1.3ȱSensingȱheadȱarrangementȱ Theȱ proposedȱ sensingȱ strategyȱ forȱ Starlifterȱ robotȱ showsȱ theȱ needȱ forȱ aȱ sensingȱ headȱ toȱ beȱ attachedȱ toȱ theȱ endeffectorȱ orȱ toȱ beȱ placedȱ inȱ aȱ suitableȱ positionȱ thatȱ avoidsȱ collisionsȱ withȱ theȱ toolsȱ orȱ theȱ arm.ȱ Theȱ sensingȱ headȱincludesȱthreeȱtypesȱofȱsensor:ȱ x aȱ visionȱ sensor,ȱ whichȱ isȱ aȱ CCTVȱ cameraȱ forȱ inȬsituȱ monitoringȱofȱtheȱworkingȱplace,ȱȱ x ultrasonicȱ sensorsȱ forȱ endeffectorȱ alignmentȱ toȱ theȱ workingȱarea,ȱ x aȱrebarȱlocatorȱforȱreinforcementsȱdetection.ȱȱ ȱ

ȱ (a)ȱ ȱ

ȱ (b)ȱ Fig.ȱ12ȱTheȱrail/roadȱtruckȱsimulationȱ ȱ ȱ

Theȱsensingȱheadȱcanȱbeȱattachedȱtoȱaȱtoolȱchangerȱdockȱifȱ itȱisȱgoingȱtoȱbeȱattachedȱtoȱtheȱendeffector.ȱFig.ȱ13ȱshowsȱ aȱ designȱ forȱ theȱ sensingȱ headȱ thatȱ includesȱ ultrasonicȱ sensorsȱ andȱ CCTVȱ camera.ȱ Thisȱ designȱ makesȱ itȱ impossibleȱ toȱ senseȱ atȱ theȱ sameȱ timeȱ asȱ operatingȱ theȱ tools.ȱ Itȱ isȱ howeverȱ possibleȱ forȱ theȱ robotȱ controllerȱ toȱ storeȱ theȱ sensingȱ dataȱ andȱ useȱ itȱ afterȱ detachingȱ theȱ sensingȱhead.ȱThisȱdesignȱcouldȱbeȱsuitableȱforȱtheȱrebarȱ locatorȱ sensorȱ inȱ whichȱ theȱ scanningȱ processȱ forȱ steelȱ reinforcementȱ shouldȱ beȱ doneȱ beforeȱ toolȱ positioning.ȱ Severalȱdesignsȱhaveȱbeenȱevaluatedȱusingȱtheȱsimulationȱ packageȱ toȱ achieveȱ aȱ suitableȱ solutionȱ forȱ theȱ sensingȱ head.ȱ

487


ȱ

ȱ

Fig.ȱ13ȱSensingȱheadȱsimulationȱ ȱ 6.4.1.4ȱMotionȱplanningȱ Theȱcommonȱ useȱofȱtheȱsimulationȱprocessȱisȱforȱmotionȱ planningȱ andȱ checkingȱ pathsȱ forȱ resolvedȱ motion.ȱ Itȱ isȱ neededȱ toȱ identifyȱ theȱ workingȱ envelopeȱ ofȱ theȱ robotȱ toȱ positionȱ theȱ robotȱ insideȱ itsȱ workingȱ envelopeȱ beforeȱ attemptingȱtoȱplanȱtheȱmotionȱofȱtheȱendeffectorȱrelativeȱ toȱ theȱ modelledȱ environment.ȱ Theȱ identificationȱ ofȱ theȱ workingȱ envelopeȱ enablesȱ theȱ calculationȱ ofȱ theȱ maximumȱplanȱareaȱthatȱtheȱendeffectorȱcanȱcontinuouslyȱ scan.ȱFromȱtheȱexaminationȱofȱtheȱworkingȱenvelope,ȱtheȱ maximumȱ verticalȱ rectangularȱ planȱ areaȱ thatȱ theȱ robotȱ 2 canȱ scanȱ isȱ aboutȱ 5 m ȱ inȱ freeȱ space.ȱ Theȱ calculationȱ ofȱ

theȱ maximumȱ scanningȱ areaȱ providesȱ informationȱ aboutȱ theȱ productivityȱ ofȱ theȱ robotȱ inȱ caseȱ itȱ isȱ usedȱ forȱ otherȱ applicationsȱ suchȱ asȱ blastingȱ andȱ spraying.ȱ Theȱ simulationȱ packageȱ canȱ alsoȱ calculateȱ theȱ optimumȱ positionȱ ofȱ theȱ robotȱ relativeȱ toȱ theȱ modelledȱ workingȱ area.ȱ Allȱ plannedȱ motionsȱ ofȱ theȱ robotȱ canȱ beȱ recordedȱ andȱ viewedȱ asȱ videoȱ clipsȱ thatȱ canȱ beȱ passedȱ toȱ supervisorsȱ andȱcustomersȱforȱreviewingȱorȱpresentationȱofȱtheȱwork.ȱ Workspaceȱ simulationȱ packageȱ providesȱ theȱ facilityȱ ofȱ recordingȱ theȱ plannedȱ motionȱ inȱ theȱ formȱ ofȱ trackȱ filesȱ which,ȱ withȱ someȱ manipulation,ȱ canȱ beȱ convertedȱ toȱ aȱ robotȱ levelȱ languageȱ orȱ asȱ inȱ caseȱ ofȱ theȱ ATCȱ controllerȱ userȱinterfaceȱtoȱtaskȱlanguageȱfiles.ȱȱ

ȱ 6.4.1.5ȱEnvironmentȱmodellingȱ TheȱoffȬlineȱprogrammingȱprocessȱofȱconstructionȱtasksȱisȱ requiredȱ toȱ beȱ repeatedȱ forȱ anyȱ changeȱ inȱ theȱ workingȱ environmentȱ orȱ theȱ characteristicsȱ ofȱ theȱ processesȱ involved.ȱItȱisȱnotȱfeasibleȱtoȱstartȱfromȱscratchȱforȱeveryȱ programmingȱtaskȱi.e.ȱtoȱbuildȱaȱmodelȱforȱeachȱtaskȱfromȱ scratch.ȱForȱspecificȱapplicationsȱofȱtheȱStarlifterȱrobotȱitȱisȱ recommendedȱtoȱbuildȱaȱsimulationȱlibraryȱthatȱcontainsȱallȱ theȱ componentsȱ involvedȱ inȱ specificȱ tasks.ȱ Theseȱ componentsȱ includeȱ theȱ robot,ȱ tools,ȱ deliveryȱ vehicles,ȱ mobilityȱ devicesȱ andȱ sensingȱ head.ȱ Inȱ additionȱ toȱ theseȱ components,ȱ modelsȱ forȱ theȱ commonȱ shapesȱ ofȱ theȱ workingȱenvironmentsȱsuchȱasȱwalls,ȱfloors,ȱbridges,ȱandȱ tunnels.ȱ Theȱ useȱ ofȱ readyȬmadeȱ simulationsȱ forȱ theseȱ componentsȱ acceleratesȱ theȱ programmingȱ process.ȱ Theȱ simulationȱ packagesȱ allowȱ theȱ implementationȱ ofȱ theȱ readyȬmadeȱ componentsȱ inȱ additionȱ toȱ theȱ CADȱ drawingsȱ ofȱ theȱ workingȱ environment.ȱ Itȱ isȱ howeverȱ

488

necessaryȱ toȱ convertȱ theȱ CADȱ drawingsȱ toȱ aȱ readableȱ formatȱthatȱtheȱsimulationȱpackageȱcanȱimplementȱȱ ȱ 6.4.1.6ȱTaskȱmonitoringȱ Taskȱ monitoringȱ isȱ performedȱ inȱ realȱ timeȱ andȱ involvesȱ theȱ simulationȱ packageȱ beingȱ connectedȱ toȱ theȱ actualȱ robotȱ usingȱ aȱ suitableȱ interface.ȱ Thisȱ process,ȱ inȱ combinationȱwithȱaȱCCTVȱcamera,ȱgivesȱaȱclearȱimageȱofȱ theȱrobotȱmovingȱinȱtheȱworkingȱenvironment.ȱ Newȱ versionsȱ ofȱ simulationȱ packagesȱ provideȱ highȬlevelȱ graphics,ȱwhichȱcanȱsimulateȱtheȱactualȱworldȱeffectively.ȱ Someȱ packagesȱ canȱ provideȱ kinematicalȱ andȱ dynamicȱ informationȱ ofȱ theȱ simulatedȱ robot,ȱ whichȱ isȱ veryȱ usefulȱ inȱtheȱrobotȱcontrollerȱdesign.ȱ ȱ 6.4.1.7ȱCostȱestimationȱ Theȱ graphicalȱ simulationȱ ofȱ theȱ roboticȱ systemȱ componentsȱ andȱ theȱ workingȱ environmentȱ providesȱ excellentȱ informationȱ thatȱ canȱ beȱ usedȱ inȱ taskȱ costȱ calculations.ȱ Basedȱ onȱ theȱ tracksȱ filesȱ createdȱ byȱ theȱ simulationȱ processȱ inȱ additionȱ toȱ theȱ fixedȱ costȱ ofȱ theȱ systemȱcomponentsȱandȱoverheadȱcost,ȱaȱrealisticȱcostȱcanȱ beȱ calculatedȱ beforeȱ theȱ actualȱ jobȱ isȱ started.ȱ Inȱ theȱ followingȱ sectionȱ aȱ detailedȱ costȱ analysisȱ ofȱ aȱ taskȱ isȱ presented.ȱ Inȱ thisȱ study,ȱ aȱ taskȱ timeȱ evaluationȱ techniqueȱ willȱ beȱ usedȱ toȱ determineȱ theȱ timeȱ consumedȱ byȱ theȱ simulatedȱ robotȱ toȱ performȱ aȱ task.ȱ Aȱ delayȱ timeȱ basedȱ onȱ experimentalȱworkȱisȱthenȱaddedȱtoȱtheȱsimulatedȱtimeȱtoȱ obtainȱtheȱactualȱtimeȱthatȱtheȱrobotȱtakesȱtoȱperformȱtheȱ sameȱ taskȱ inȱ theȱ realȱ world.ȱ Thisȱ delayȱ timeȱ isȱ site/task/robotȱdependent.ȱ Fourȱ typesȱ ofȱ motionȱ areȱ consideredȱ basedȱ onȱ thoseȱ definedȱ byȱ Hassȱ andȱ Hsiehȱ inȱ 1993ȱ asȱ theȱ elementalȱ motions,ȱ whichȱ describeȱ allȱ theȱ operationsȱ ofȱ aȱ constructionȱmanipulator:ȱ ȱ

a. b. c. d.

PlatformȱMotionȱ GrossȱArmȱMotionȱ FineȱArmȱMotionȱ EndeffectorȱMotionȱ

ȱ

Consideringȱtheȱfactȱthatȱtheȱsimulationȱprocessȱdoesȱnotȱ takeȱ intoȱ accountȱ theȱ effectȱ ofȱ theȱ environmentȱ onȱ theȱ robotȱperformanceȱ(theȱsimulatedȱrobotȱmovesȱinȱanȱidealȱ environmentȱ withȱ instantȱ responseȱ toȱ theȱ requiredȱ motion),ȱtheȱcalculatedȱtimeȱforȱeachȱmotionȱtypeȱshouldȱ considerȱ theȱ delaysȱ generatedȱ dueȱ toȱ theȱ effectȱ ofȱ theȱ environment.ȱForȱinstanceȱwhenȱusingȱaȱtelescopicȱboomȱ toȱ positionȱ theȱ robot,ȱ theȱ simulatedȱ boomȱ doesȱ notȱ considerȱlateralȱvibrationsȱofȱtheȱactualȱboomȱtipȱandȱtheȱ effectȱofȱfrictionȱandȱwindȱforceȱonȱtheȱtimeȱtakenȱtoȱreachȱ theȱdesiredȱposition.ȱInȱadditionȱthereȱisȱtheȱerrorȱdueȱtoȱ humanȱfactorsȱinȱoperatingȱtheȱboomȱwhichȱareȱcorrectedȱ byȱ trialȱ andȱ errorȱ andȱ whichȱ addȱ additionalȱ timeȱ toȱ theȱ estimatedȱ time.ȱ Otherȱ delaysȱ couldȱ beȱ generatedȱ dueȱ toȱ theȱ sensingȱ &ȱ decisionȱ processȱ andȱ fromȱ forceȱ buildȬupȱ time,ȱespeciallyȱforȱhydraulicȱrobots.ȱ


6.5ȱTheȱcontrollerȱdevelopmentȱȱ Theȱrobotȱcontrollerȱcanȱbeȱconsideredȱasȱtheȱbrainȱofȱtheȱ robot,ȱ whichȱ isȱ responsibleȱ forȱ receivingȱ andȱ sendingȱ signalsȱ fromȱ andȱ toȱ theȱ armȱ accordingȱ toȱ theȱ demandedȱ positionȱ andȱ rate.ȱ Asȱ describedȱ inȱ sectionȱ 6.,ȱ theȱ preliminarilyȱ functionalȱ decompositionȱ ofȱ theȱ Starlifterȱ controllerȱmoduleȱisȱdividedȱintoȱtwoȱmainȱsubȬmodules,ȱ theȱ highȱ levelȱ controllerȱ andȱ theȱ lowȱ levelȱ controllerȱ asȱ canȱ beȱ seenȱ inȱ Fig.ȱ 9ȱ Theȱ highȱ levelȱ controllerȱ orȱ theȱ kinematicȱ controllerȱ canȱ beȱ consideredȱ toȱ beȱ aȱ softwareȱ basedȱmoduleȱwhile,ȱtheȱlowȱlevelȱcontrollerȱorȱtheȱservoȱ controllerȱ canȱ beȱ consideredȱ toȱ beȱ aȱ hardwareȱ basedȱ module,ȱ howeverȱ softwareȱ isȱ requiredȱ toȱ configureȱ theȱ lowȱ levelȱ controllerȱ andȱ controllerȱ designȱ implementation.ȱ Theȱ functionalȱ decompositionȱ ofȱ theȱ controllerȱ underȱ developmentȱ isȱ basicallyȱ derivedȱ fromȱ theȱ currentȱ Starlifterȱ controllerȱ whichȱ consistsȱ ofȱ theȱ kinematicȱ controllerȱ knownȱ asȱ ATCȱ andȱ theȱ existingȱ servoȱ controllerȱ developedȱ byȱ UKȱ Roboticsȱ Ltd.ȱ Itȱ isȱ henceȱ requiredȱ toȱ reȬengineerȱ aȱ newȱ controllerȱ toȱ enableȱ theȱuseȱofȱrealȬtimeȱsensorsȱandȱotherȱelementsȱsuchȱasȱaȱ linkȱ toȱ theȱ simulationȱ packageȱ interface.ȱ Theȱ issueȱ ofȱ usingȱexistingȱcomponentsȱofȱtheȱcurrentȱcontrollerȱinȱtheȱ developmentȱ ofȱ aȱ newȱ controllerȱ isȱ consideredȱ hereȱ inȱ whichȱ aȱ detailedȱ analysisȱ ofȱ theȱ currentȱ controllerȱ componentsȱ isȱ conductedȱ toȱ identifyȱ theȱ mainȱ functionsȱ andȱtheȱphysicalȱlayoutȱofȱtheȱcomponents.ȱȱ TheȱATCȱcontrollerȱcannotȱbeȱusedȱifȱanyȱchangeȱisȱmadeȱ toȱ theȱ servoȱ levelȱ control.ȱ Theȱ reasonȱ behindȱ thisȱ isȱ theȱ initialisationȱ codeȱ ofȱ theȱ ATCȱ software,ȱ i.e.ȱ aȱ messageȱ fromȱ theȱ servoȱ controllerȱ isȱ sentȱ toȱ theȱ ATCȱ toȱ confirmȱ thatȱ theȱ systemȱ isȱ readyȱ forȱ connectionȱ beforeȱ theȱ ATCȱ canȱ startȱ up.ȱ Currentlyȱ thereȱ isȱ noȱ accessȱ toȱ theȱ codeȱ toȱ modifyȱthisȱconfirmation.ȱȱ Inȱ theseȱ circumstancesȱ theȱ followingȱ componentsȱ areȱ identifiedȱforȱdevelopment:ȱ ȱ 1. Aȱkinematicsȱcontrollerȱ(highȬlevelȱcontroller)ȱtoȱ replaceȱtheȱATCȱcontrollerȱ 2. Aȱ lowȱ levelȱ controllerȱ basedȱ onȱ theȱ existingȱ componentsȱȱ ȱ 6.5.1ȱTheȱhighȱlevelȱcontrollerȱ Theȱ mainȱ reasonȱ ofȱ developingȱ aȱ newȱ controllerȱ forȱ Starlifterȱ robotȱ isȱ theȱ currentȱ difficultyȱ inȱ accessingȱ orȱ modifyingȱ theȱ existingȱ kinematicsȱ codeȱ associatedȱ withȱ theȱoperationȱofȱtheȱATCȱcontroller.ȱTheȱstartingȱpointȱinȱ developingȱ aȱ newȱ controllerȱ isȱ establishingȱ theȱ mainȱ functionsȱ ofȱ theȱ controller,ȱ whichȱ inȱ fact,ȱ willȱ resembleȱ theȱ functionsȱ thatȱ theȱ existingȱ ATCȱ performs.ȱ Otherȱ functionsȱcanȱthenȱbeȱaddedȱtoȱdevelopȱaȱmoreȱadvancedȱ controllerȱ itȱ isȱ moreȱ convenientȱ toȱ useȱ anȱ abbreviatedȱ nameȱ forȱ theȱ newȱ controller,ȱ whichȱ willȱ beȱ calledȱ SICOȱ (Starlifterȱ Interfaceȱ Controllerȱ Operator).ȱ Theȱ mainȱ functionsȱ ofȱ theȱ SICOȬHLȱ canȱ beȱ summarisedȱ inȱ theȱ followingȱpointsȱ ȱ

6.5.1.1ȱTeleoperationalȱcontrolȱȱ Thisȱfunctionȱprovidesȱaȱfacilityȱforȱtheȱoperatorȱtoȱmoveȱ theȱrobotȱusingȱjoysticks.ȱThisȱmodeȱofȱoperationȱrequiresȱ theȱ presenceȱ ofȱ aȱ humanȱ inȱ theȱ loopȱ atȱ allȱ timesȱ andȱ itȱ alsoȱ providesȱ controlȱ ofȱ theȱ individualȱ jointsȱ asȱ wellȱ asȱ resolvedȱmotion.ȱȱ ȱ 6.5.1.2ȱPreȬprogrammedȱmotionȱcontrolȱ Thisȱ facilityȱ providesȱ advancedȱ controlȱ ofȱ theȱ robotȱ motionȱ andȱ itȱ canȱ beȱ consideredȱ toȱ constituteȱ realȱ automationȱofȱtheȱrobotȱtaskȱalthoughȱaȱhumanȱisȱstillȱinȱ theȱ loop,ȱ butȱ withȱ minimumȱ intervention.ȱ PreȬ programmedȱ motionȱ canȱ eitherȱ beȱ derivedȱ usingȱ aȱ simulationȱ packageȱ suchȱ asȱ Workspaceȱ whichȱ isȱ thenȱ convertedȱ toȱ aȱ formatȱ thatȱ theȱ robotȱ controllerȱ canȱ understand,ȱ orȱ itȱ canȱ beȱ programmedȱ directlyȱ usingȱ aȱ specialȱ editorȱ builtȱ intoȱ theȱ controllerȱ software,ȱ asȱ inȱ theȱ caseȱofȱtheȱtaskȱlanguageȱeditorȱinȱtheȱATCȱcontroller.ȱȱ ȱ 6.5.1.3ȱUserȱdataȱinput/outputȱandȱvisualisationȱȱ Thisȱfacilityȱisȱaȱbasicȱfacility,ȱwhichȱisȱrequiredȱtoȱinputȱaȱ desiredȱ robotȱ positionȱ orȱ toȱ monitorȱ theȱ currentȱ robotȱ positionȱ inȱ termsȱ ofȱ theȱ jointȱ anglesȱ ofȱ theȱ Cartesianȱ positionȱ ofȱ theȱ endȱ effector.ȱ Itȱ isȱ alsoȱ usefulȱ toȱ issueȱ warningsȱ forȱ violationȱ ofȱ limitsȱ atȱ theȱ jointsȱ orȱ theȱ robotȱ envelopeȱ ȱ 6.5.1.4ȱSensorȱdataȱfusionȱ Thisȱ isȱ theȱ addedȱ valueȱ toȱ theȱ systemȱ whichȱ providesȱ moreȱ advancedȱ controlȱ facility,ȱ whichȱ couldȱ leadȱ ultimatelyȱtoȱaȱpartiallyȱautonomousȱrobot.ȱThisȱrequiresȱ suitableȱ sensorsȱ forȱ robotȱ positioning,ȱ endȱ effectorȱ adjustmentȱandȱtaskȱareaȱmonitoringȱfacilities.ȱInȱfactȱitȱisȱ theȱ mainȱ aimȱ ofȱ theȱ currentȱ researchȱ projectȱ toȱ addȱ intelligenceȱ toȱ theȱ currentȱ robot.ȱ Developingȱ SICOȱ withȱ theseȱ facilitiesȱ couldȱ openȱ theȱ doorȱ forȱ futureȱ implementationȱofȱsensors.ȱ ȱ 6.5.2ȱRobotȱkinematicsȱ 6.5.2.1ȱForwardȱkinematicsȱ ForwardȱkinematicsȱdescribesȱtheȱCartesianȱpositionȱandȱ orientationȱofȱtheȱendȬeffectorȱinȱtermsȱofȱtheȱmanipulatorȱ jointsȱangles.ȱToȱsolveȱtheȱproblemȱofȱforwardȱkinematics,ȱ aȱsimpleȱalgorithmȱpresentedȱbyȱMckerrowȱinȱ1991ȱcanȱbeȱ used.ȱ Howeverȱ itȱ isȱ necessaryȱ toȱ defineȱ severalȱ terms,ȱ whichȱ canȱ helpȱ inȱ solvingȱ theȱ problemȱ ofȱ forwardȱ kinematics.ȱ Theȱ firstȱ termȱ isȱ theȱ generalȱ transformationȱ matrix.ȱ Thisȱ matrixȱ relatesȱ theȱ endȬeffectorȱ positionȱ andȱ orientationȱinȱrelationȱtoȱtheȱbaseȱcoordinateȱsystem;ȱthisȱ matrixȱcanȱbeȱdefinedȱas:ȱ ȱ ȱ (1) ȱ ȱ Where:ȱȱ p:ȱLocationȱofȱtheȱoriginȱofȱtheȱendȬeffectorȱframeȱ

489


x:ȱDirectionȱofȱtheȱxȬaxisȱofȱtheȱendȬeffectorȱframeȱ y:ȱDirectionȱofȱtheȱyȬaxisȱofȱtheȱendȬeffectorȱframeȱ z:ȱDirectionȱofȱtheȱzȬaxisȱofȱtheȱendȬeffectorȱframeȱ ȱ

ª px º «p » « y» « pz » « » «I » «T » « » «\ »

[(( C1C 2 C 3 C1 S 2 S 3 )C 4 ( C1C 2 S 3 C1 S 2 C 3 ) S 4 )C 5 S 1 S 5 ]C 6

xx

[(C1C 2 C 3 C1 S 2 S 3 ) S 4 ( C1C 2 S 3 C1 S 2 C 3 )C 4 ]S 6

ȱ

ȱ

(2)ȱ

[(( C1C 2 C 3 C1 S 2 S 3 )C 4 ( C1C 2 S 3 C1 S 2 C 3 ) S 4 )C 5 S 1 S 5 ]S 6

yx

[( C1C 2 C 3 C1 S 2 S 3 ) S 4 ( C1C 2 S 3 C1 S 2 C 3 )C 4 ]C 6

ȱ

ȱ

(3)ȱ

((C1C 2 C 3 C1 S 2 S 3 )C 4 (C1C 2 S 3 C1 S 2 C 3 ) S 4 ) S 5 S1C 5

zx

ȱ

ȱ

ȱ

(4)ȱ

[(( S 1C 2 C 3 S 1 S 2 S 3 )C 4 ( S 1C 2 S 3 S 1 S 2 C 3 ) S 4 )C 5 C1 S 5 ]C 6

xy

[( S 1C 2 C 3 S 1 S 2 S 3 ) S 4 ( S 1C 2 S 3 S 1 S 2 C 3 )C 4 ]S 6

ȱ

ȱ

(5)ȱ

[(( S 1C 2 C 3 S 1 S 2 S 3 )C 4 ( S 1C 2 S 3 S 1 S 2 C 3 ) S 4 )C 5 C 1 S 5 ]S 6

yy

[( S 1C 2 C 3 S 1 S 2 S 3 ) S 4 ( S 1C 2 S 3 S 1 S 2 C 3 )C 4 ]C 6

ȱ

ȱ

(6)ȱ

(( S 1 C 2 C 3 S 1 S 2 S 3 ) C 4 ( S 1 C 2 S 3 S 1 S 2 C 3 ) S 4 ) S 5 C 1 S 5

zy

ȱ xz

(7)ȱ

(( S 2 C 3 C 2 S 3 ) C 4 ( S 2 S 3 C 2 C 3 ) S 4 ) C 5 C 6

ȱ

(( S 2 C 3 C 2 S 3 ) S 4 ( S 2 S 3 C 2 C 3 ) C 4 ) S 6

ȱ

ȱ

ȱ

(8)ȱ

yz

(( S 2 C 3 C 2 S 3 ) C 4 ( S 2 S 3 C 2 C 3 ) S 4 ) C 5 S 6 ȱ (( S 2 C 3 C 2 S 3 ) S 4 ( S 2 S 3 C 2 C 3 ) C 4 ) C 6

zz

(( S 2 C 3 C 2 S 3 ) C 4 ( S 2 S 3 C 2 C 3 ) S 4 ) S 5 ȱ

ȱ

ȱ

ȱ

ȱ

ȱ

ȱ

ȱ

(9)ȱ

(10)ȱ

[((C1C 2 C3 C1 S 2 S 3 )C 4 (C1C 2 S 3 C1 S 2 C3 ) S 4 ) S 5 S1C5 ]d 6

px

(C1C 2 C3 C1 S 2 S 3 )a 4 C 4 (C1C 2 S 3 C1 S 2 C3 )a 4 S 4 C1C 2 C3 a3 C1 S 2 S 3 a3 C1C 2 a 2 C1a1

(11)ȱ py [((S1C2C3 S1S2S3)C4 (S1C2S3 S1S2C3)S4 )S5 C1S5 ]d6 (S1C2C3 S1S2S3)C4a4 (S1C2S3 S1S2C3)S4a4 S1C2C3a3 S1S2S3a3 C2a2 S1a1

(12)ȱ pz

((S 2C3 C2 S3 )C4 (S 2 S3 C2C3 )S 4 )S5 d 6 ((S 2C3 C2 S3 )C4 a4 (S 2 S3 C2C3 )S 4 a4 S 2C3a3 C2 S3a3 S 2 a2 d1

(13)ȱ Theȱ endȬeffectorȱ orientationȱ angles,ȱ

(I ,T ,\ ) ȱ canȱ beȱ

calculatedȱ inȱ termsȱ ofȱ theȱ aboveȱ elementsȱ ofȱ theȱ homogeneousȱ transformationȱ matrixȱ usingȱ theȱ atan2ȱ (Ȭ)ȱ functionȱ whichȱ determinesȱ theȱ angleȱ inȱ itsȱ appropriateȱ quarter.ȱ Inȱ theȱ actualȱ calculationȱ toȱ obtainȱ numericalȱ resultsȱtoȱverifyȱtheȱcorrectnessȱofȱtheȱforwardȱkinematicsȱ modelȱ presentedȱ above,ȱ theȱ MATLABȱ atan2ȱ functionȱ isȱ used.ȱȱ ȱ ȱ ȱ I atan2( x y , x x ) ȱ ȱ ȱ

T

ȱ

\

ȱ

atan2( x z , ( x x C (I ) x y S (I ))) ȱ

ȱ

atan2( y z , z z ) ȱ ȱ

ȱ

ȱ ȱ

ȱ ȱ

ȱ

ȱ ȱ

ȱ ȱ

ȱ

(14)ȱ

TE

A1 A2 A3 A4 A5 A6 ȱ

B

A11 TE

A2 A3 A4 A5 A6 ȱ B

A21 A11 TE

A3 A4 A5 A6 ȱ

B A31 A21 A11 TE

A4 A5 A6 ȱ

B A41 A31 A21 A11 TE

A5 A6 ȱ B

A51 A41 A31 A21 A11 TE

(17)ȱ

A6 ȱ

ȱ

(18)ȱ

ȱ

(19)ȱ

ȱ

(20)ȱ

ȱ

(21)ȱ

ȱ

(22)ȱ

ȱ

(23)ȱ

Byȱ equatingȱ theȱ correspondingȱ elementsȱ inȱ eachȱ sideȱ ofȱ theȱequationȱandȱsimplifyingȱPaulȱ(1981).ȱThisȱyieldsȱtheȱ jointsȱanglesȱasȱfollows:ȱ

T1

§ p y d6 z y tan -1 ¨¨ © px d6 zx

·ȱ ¸¸ ¹

ȱ

(24)ȱ

§ ·ȱ ȱ zz (25)ȱ ¸ tan -1 ¨ ¨ C1 z x S1 z y ¸ © ¹ .ȱHavingȱgotȱtheȱvalueȱofȱ T 234 ,ȱ (T 2 T 3 T 4 )

T 234

(16)ȱ

inȱmmȱandȱorientationȱinȱdegreesȱcalculatedȱbyȱtheȱaboveȱ formulationȱare:ȱ

490

B

(15)ȱ

ȱ Theȱ zeroȱ positionȱ ofȱ theȱ Starlifterȱ robot,ȱ i.e.ȱ atȱ T1 T 2 T 3 T 4 T 5 T 6 0 ,ȱtheȱendȬeffectorȱpositionȱ

ȱ

ȱ Thisȱ isȱ consistentȱ withȱ theȱ simulationȱ resultsȱ andȱ theȱ actualȱ robotȱ positionȱ ifȱ weȱ takeȱ intoȱ accountȱ theȱ sameȱ referenceȱ orȱ theȱ sameȱ baseȱ coordinates.ȱ Otherȱ testsȱ wereȱ madeȱtoȱcompareȱtheȱforwardȱkinematicsȱmodelȱwithȱtheȱ actualȱrobot.ȱGoodȱconsistencyȱinȱpositionȱandȱorientationȱ wereȱobtained.ȱ ȱ 6.5.2.2ȱInverseȱkinematicsȱȱ Theȱinverseȱkinematicsȱproblemȱdealsȱwithȱfindingȱvaluesȱ forȱtheȱjointsȱvariablesȱforȱaȱgivenȱCartesianȱpositionȱandȱ orientationȱofȱtheȱendȬeffector.ȱTheȱsolutionȱofȱtheȱinverseȱ kinematicsȱproblemȱisȱcalledȱtheȱarmȱsolution,ȱwhichȱcanȱ beȱ foundȱ fromȱ theȱ armȱ transformȱ usingȱ theȱ inverseȱ kinematicsȱ heuristic,ȱ Mckerrowȱ 1991.ȱ Thisȱ heuristicȱ isȱ aȱ methodȱ toȱ findȱ aȱ solutionȱ butȱ isȱ notȱ sometimesȱ failsȱ toȱ convergeȱ onȱ aȱ solution.ȱ Anȱ algorithmȱ developedȱ byȱ Mckerrowȱ 1991ȱ toȱ solveȱ theȱ problemȱ ofȱ inverseȱ kinematicsȱisȱusedȱinȱtheȱpresentȱanalysis.ȱTheȱbasicȱideaȱ ofȱ thisȱ algorithmȱ isȱ toȱ equateȱ theȱ generalȱ transformationȱ matrixȱ toȱ theȱ manipulatorȱ matrixȱ andȱ toȱ lookȱ atȱ theȱ correspondentȱ elements,ȱ which,ȱ containȱ oneȱ jointȱ variable,ȱ orȱ twoȱ elements,ȱ whichȱ couldȱ leadȱ toȱ oneȱ jointȱ variable.ȱ Thisȱ procedureȱ canȱ beȱ repeatedȱ forȱ differentȱ combinationsȱ ofȱ theȱ transformationȱ matrices.ȱ Thisȱ procedureȱproducesȱsixȱequationsȱasȱfollows:ȱ

ȱ ȱ

ª2484º « 0 » » « « 380 » ȱ » « « 90 » « 0 » » « « 90 »

Whereȱ T 234

theȱ valueȱ ofȱ anyȱ angleȱ ofȱ theȱ threeȱ canȱ beȱobtainedȱ onceȱ anȱexpressionȱisȱobtainedȱforȱtheȱotherȱtwoȱangles.ȱȱ ȱ


ȱ

T3

§S · tan 1 ¨¨ 3 ¸¸ ȱȱ © C3 ¹

ȱ

ȱ

(27)ȱ

ȱ Nowȱtheȱvalueȱofȱ T 4 ȱcanȱbeȱcalculatedȱasȱfollows:ȱ

T 4 T 234 T 2 T 3 ȱ

ȱ

T5

§ C 234 (C1 z x S1 z y ) S 234 tan 1 ¨ ¨ S1 z x C1 z y ©

T6

§ S1 y x C1 y y tan 1 ¨ ¨ S1 x x C1 x y ©

· ¸ȱ ¸ ¹

ȱ (28)ȱ

ȱ

ȱ

· ¸ȱ ¸ ¹

(29)ȱ

(30)ȱ

Joint position, (degrees)

Cartesian position, (m)

ȱ Havingȱ obtainedȱ theȱ valuesȱ ofȱ theȱ sixȱ jointsȱ anglesȱ independently,ȱ aȱ closedȱ formȱ solutionȱ forȱ theȱ inverseȱ kinematicsȱ problemȱ isȱ obtained.ȱ Itȱ isȱ howeverȱ advantageousȱ toȱ putȱ limitsȱ onȱ extremeȱ valuesȱ forȱ anglesȱ suchȱasȱzeroȱandȱ90ȱandȱ180ȱdegreesȱtoȱavoidȱoverflowȱinȱ theȱ programȱ byȱ dividingȱ byȱ zero.ȱ Theseȱ limitsȱ willȱ generateȱ anȱ accumulateȱ errorȱ aboutȱ 0.1ȱ degreeȱ whichȱ isȱ acceptable.ȱȱ ȱ 6.5.2.3ȱTrajectoryȱgenerationȱȱ Theȱ trajectoryȱ generationȱ algorithmȱ usedȱ inȱ theȱ currentȱ workȱisȱbasedȱonȱtheȱworkȱofȱPaulȱ(1981.).ȱFig.ȱ14ȱshowsȱ theȱtrajectoriesȱinȱjointȱandȱCartesianȱspacesȱforȱarbitraryȱ motionȱfromȱpointȱtoȱpoint.ȱ ȱ ȱ 3 ȱ x-position 2.5 y-position ȱ z-position 2 ȱ 1.5 ȱ 1 ȱ 0.5 ȱ 0 ȱ -0.5 ȱ -1 ȱ 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 Time (s) ȱ 100 ȱ ȱ 50 ȱ 0 ȱ ȱ -50 Joint 1 ȱ Joint 2 -100 Joint 3 ȱ Joint 4 Joint 5 ȱ -150 Joint 6 ȱ -200 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 ȱ Time (s)

ȱ Fig.ȱ 14ȱ Trajectoriesȱ generationȱ inȱ Cartesianȱ andȱ jointsȱ spacesȱforȱarbitraryȱCartesianȱpositionsȱ

6.5.3ȱLayoutȱofȱtheȱkinematicsȱcontrollerȱ Theȱ kinematicsȱ controllerȱ isȱ aȱ softwareȬbasedȱ module.ȱ Theȱefficiencyȱofȱtheȱdataȱflowȱbetweenȱitsȱcomponentsȱisȱ ofȱgreatȱimportanceȱowingȱtoȱtheȱcriticalityȱofȱtheȱmodule.ȱ Theȱ behaviouralȱ modelȱ inȱ Fig.ȱ 15ȱ showsȱ theȱ interrelationshipȱ betweenȱ theȱ moduleȱ componentsȱ inȱ termsȱ ofȱ theȱ behaviourȱ modelȱ shownȱ inȱ Fig.ȱ 9.ȱ Theȱ behaviouralȱ modelȱ allowsȱ forȱ theȱ divisionȱ ofȱ theȱ kinematicsȱcontrollerȱintoȱfiveȱcomponentsȱasȱfollows:ȱ ȱ 1. Interfacesȱȱ Thisȱcomponentȱrepresentsȱtheȱinterfacesȱtoȱtheȱinputȱ devicesȱsuchȱasȱjoysticksȱandȱotherȱinterfacesȱsuchȱasȱtheȱ simulatedȱrobotȱandȱsensors.ȱ ȱ 2. Demandȱ Thisȱ subȬmoduleȱ dealsȱ withȱ theȱ demandedȱ valuesȱ ofȱ variablesȱandȱratesȱinȱjointȱspaceȱandȱCartesianȱspaceȱ ȱ 3. Processingȱ ThisȱsubȬmoduleȱdealsȱwithȱprocessingȱtheȱinputȱvariableȱ andȱ ratesȱ forȱ conversionȱ intoȱ interchangeableȱ forms.ȱ Itȱ alsoȱ dealsȱ withȱ trajectoriesȱ generationȱ inȱ jointȱ spaceȱ andȱ Cartesianȱ space.ȱ Otherȱ functionsȱ includeȱ singularitiesȱ detectionȱ andȱ issuingȱ warningsȱ forȱ exceedingȱ limitsȱ orȱ ranges.ȱ ȱ 4. Outputȱandȱwarningsȱ InȱthisȱsubȬmodule,ȱvaluesȱforȱtheȱjointȱvariables,ȱ Cartesianȱvariablesȱandȱratesȱareȱmonitoredȱandȱwarningsȱ areȱoutputȱtoȱtheȱuser.ȱ ȱ 5. Implementationȱ Thisȱ partȱ dealsȱ withȱ theȱ lowȬlevelȱ controllerȱ interfaceȱ inȱ which,ȱdataȱinȱtheȱformȱofȱdemandedȱjointsȱvariablesȱandȱ ratesȱ areȱ passedȱ toȱ theȱ lowȬlevelȱ controllerȱ andȱ theȱ currentȱjointȱvariablesȱfedȬbackȱtoȱtheȱuserȱinterface.ȱ ȱ ȱ Interfaces

Demand

Processing

Demanded Cartesian Position

Demanded Position of The Joints

Output and Warnings

Current Position of The Joints

Joints trajectories Generation

Current Cartesian Position

Forward Kinematics Joints and Cartesian speed limit check

Demanded velocity of the Joints Inverse Kinematics Demanded Cartesian velocity

Implementation

Jacobian Matrix and Determinant

Inverse Jacobian

The Kinematics Controller

The user Interface Implemented

Under Development

The Low-Level Controller

(26)ȱ

Joints range limit check

Robot base position (Rotoscan)

· ¸ ȱȱ ¸ ¹

Inputs and other interfaces

§ (C3 a3 a 2 ) p 'y S 3 a3 p x' tan 1 ¨ ¨ (C3 a3 a 2 ) p x' S 3 a3 p 'y ©

End-effector Orientation (U.

T2

Interfaces

ȱ

Fig.ȱ15ȱKinematicsȱcontrollerȱlayoutȱ

491


ȱ 6.5.4.2ȱStarlifterȱdynamicalȱmodellingȱ Theȱ transferȱ functionȱ ofȱ theȱ Starlifterȱ robotȱ which,ȱ representsȱ theȱ systemȱ behaviour,ȱ canȱ beȱ obtainedȱ byȱ usingȱ dataȱ basedȱ modellingȱ techniques.ȱ Oneȱ ofȱ theȱ successfulȱ techniquesȱ isȱ thatȱ developedȱ byȱ Youngȱ etȱ alȱ (1996)ȱ whichȱ hasȱ foundȱ aȱ wideȱ rangeȱ ofȱ applicationsȱ includingȱheavyȱmachinery,ȱDixonȱetȱalȱ(1997),ȱintelligentȱ excavator,ȱ Guȱ etȱ al,ȱ (2004)ȱ andȱ environmentȱ relatedȱ applicationsȱ Leeȱ etȱ alȱ (1998)ȱ andȱ Taylorȱ etȱ alȱ (1998).ȱ Theȱ systemȱidentificationȱtoolboxȱofȱMATLABȱcanȱbeȱusedȱinȱ conjunctionȱ withȱ theȱ CAPTAINȱ toolboxȱ developedȱ byȱ Youngȱ etȱ alȱ (2003)ȱ toȱ obtainȱ theȱ transferȱ functionȱ ofȱ theȱ

492

robotȱ inȱ discreteȱ time.ȱ Theȱ baseȱ forȱ theȱ dataȬbasedȱ modellingȱ techniqueȱ isȱ toȱ collectȱ informationȱ aboutȱ theȱ behaviourȱ ofȱ theȱ robotȱ asȱ aȱ resultȱ ofȱ varyingȱ theȱ inputȱ signalsȱ toȱ theȱ robotȱ valvesȱ i.e.ȱ toȱ relateȱ theȱ inputȱ u,ȱ (Voltage)ȱ toȱ theȱ outputȱ yȱ (theȱ jointȱ positionȱ T ).ȱ Severalȱ testsȱ haveȱ beenȱ conductedȱ toȱ evaluateȱ theȱ transferȱ functionȱ ofȱ theȱ Starlifterȱ robotȱ jointȱ (1).ȱ Owingȱ toȱ maintenanceȱ problems,ȱ theȱ workȱ couldn’tȱ beȱ completedȱ onȱallȱofȱtheȱjointsȱorȱimplementedȱinȱtheȱcontrollerȱinȱitsȱ finalȱ form.ȱ Theȱ workȱ presentedȱ hereȱ isȱ toȱ illustrateȱ theȱ applicabilityȱ ofȱ dataȬbasedȱ modellingȱ andȱ controllerȱ designȱ usingȱ theȱ ProportionalȬIntegralȬPlusȱ (PIP)ȱ controlȱ philosophy.ȱ ȱ 6.5.4.3ȱDataȱcollectionȱandȱanalysisȱ Aȱseriesȱofȱplannedȱexperimentsȱwereȱcarriedȱoutȱonȱtheȱ Starlifterȱ jointȱ (1)ȱ toȱ produceȱ inputȬoutputȱ timeȱ seriesȱ dataȱ relatingȱ theȱ angularȱ positionȱ ofȱ jointȱ (1)ȱ andȱ theȱ valveȱ inputȱ voltage.ȱ Fig.ȱ 16ȱ showsȱ theȱ variationȱ ofȱ theȱ angularȱpositionȱofȱjointȱ(1)ȱwithȱtheȱinputȱvoltageȱtoȱtheȱ jointȱvalve.ȱTwoȱimportantȱobservationsȱcanȱbeȱextractedȱ fromȱ thisȱ figure;ȱ theȱ firstȱ observationȱ isȱ theȱ linearȱ variationȱofȱtheȱjointȱangleȱforȱconstantȱinputȱvoltage.ȱTheȱ secondȱ observationȱ isȱ theȱ samplingȱ rateȱ ofȱ theȱ resolverȱ whichȱisȱveryȱlowȱforȱaȱresponsiveȱdynamicȱsystemȱsuchȱ asȱ aȱ robot.ȱ Theȱ reasonȱ behindȱ thisȱ slowȱ samplingȱ rateȱ isȱ theȱ doubleȱ serialȱ readingsȱ ofȱ theȱ resolverȱ data.ȱ Theȱ resolverȱ signalȱ isȱ readȱ throughȱ aȱ resolverȱ toȱ digitalȱ converterȱ andȱ thenȱ transmittedȱ toȱ theȱ serialȱ portȱ ofȱ theȱ servoȬlevelȱPCȱandȱthenȱthisȱsignalȱisȱtransmittedȱagainȱtoȱ theȱ serialȱ portȱ ofȱ theȱ SICOȱ PCȱ inȱ whichȱ theȱ signalȱ isȱ processedȱagainȱandȱdirectedȱtoȱtheȱcontrollerȱGUI.ȱ ȱ Output Angle Input Voltage

Valve signal (V)

4.0

20 0

2.0

-20

0.0

-40

-2.0

-60 -80

-4.0 -6.0 20

Joint angle, (TR

Spline smoothing

6.0

Output Angle (deg)

6.5.4ȱLowȬlevelȱcontrollerȱ Upȱtoȱthisȱstage,ȱtheȱhighȱlevelȱcontrollerȱperformsȱallȱtheȱ mathematicalȱoperationsȱtoȱassignȱtheȱjointsȱanglesȱwhichȱ areȱ neededȱ toȱ moveȱ theȱ robotȱ endȬeffectorȱ toȱ aȱ desiredȱ positionȱdefinedȱbyȱanȱangularȱorȱCartesianȱposition.ȱȱTheȱ lowȱ levelȱ controllerȱ receivesȱ theȱ demandedȱ jointsȱ anglesȱ fromȱ theȱ highȬlevelȱ controllerȱ andȱ sendsȱ signalsȱ toȱ theȱ robotȱvalvesȱtoȱmoveȱtheȱrobotȱtoȱtheȱdesiredȱpositionȱinȱaȱ wellȱ controlledȱ motion.ȱ Theȱ currentȱ Starlifterȱ lowȬlevelȱ controllerȱdesignȱisȱbasicallyȱaȱstandardȱPIDȱcontrollerȱorȱ literallyȱ aȱ PIȱ controllerȱ basedȱ onȱ independentȱ jointȱ control.ȱ Theȱ Starlifterȱ LowȬlevelȱ controllerȱ SICOȬLLȱ isȱ designedȱ toȱ replaceȱ theȱ currentȱ servoȱ controller.ȱ Someȱ changesȱ haveȱ beenȱ introducedȱ toȱ theȱ originalȱ controllerȱ layoutȱandȱcomponentsȱtoȱallowȱinterfacingȱwithȱtheȱnewȱ highȬlevelȱ controllerȱ andȱ theȱ newȱ LabVIEWȱ programmingȱ environment.ȱ Theseȱ changesȱ allowȱ onȬlineȱ modellingȱofȱtheȱrobotȱandȱchangingȱtheȱcontrollerȱgains.ȱ Aȱ LabVIEWȱ userȱ interfaceȱ hasȱ beenȱ developedȱ toȱ interfaceȱ theȱ hardwareȱ componentsȱ illustratedȱ inȱ theȱ controllerȱlayout.ȱȱ TheȱfundamentalȱfunctionsȱofȱtheȱSICOȬLLȱcontrollerȱare:ȱ A. Sendingȱsignalsȱtoȱtheȱjointsȱvalvesȱ B. Receivingȱtheȱinstantaneousȱjointsȱpositions.ȱȱ ȱ Theseȱ fundamentalȱ functionsȱ canȱ beȱ replacedȱ byȱ fourȱ mainȱfunctionsȱasȱfollows:ȱ 1. TheȱMOOGȱvalveȱinterfaceȱ 2. Internalȱsensorȱinterfaceȱ(Resolvers)ȱ 3. Controllerȱdesignȱimplementationȱ 4. TheȱHighȬlevelȱcontrollerȱinterfaceȱ ȱ 6.5.4.1ȱTheȱcontrollerȱdesignȱimplementationȱ Thisȱ isȱ theȱ heartȱ ofȱ theȱ controller.ȱ Thisȱ functionȱ isȱ decomposedȱintoȱthreeȱserialȱstepsȱnamely:ȱ 1. Dynamicȱmodellingȱ 2. Controllerȱdesignȱȱ 3. Designȱimplementationȱ ȱ TheȱSICOȬLLȱcontrolȱprovidesȱfacilitiesȱtoȱaccomplishȱtheȱ aboveȬmentionedȱ steps.ȱ Theȱ followingȱ sectionȱ describesȱ theȱ stepsȱ ofȱ thisȱ functionȱ appliedȱ toȱ Jointȱ (1)ȱ ofȱ theȱ Starlifterȱ robotȱ withȱ someȱ theoreticalȱ backgroundȱ ofȱ theȱ controllerȱdesignȱphilosophy.ȱȱ

-100

0 -20 -40 -60 -80 -100 80

100

120

140

160

180

200

220

240

260

280

300

320

ȱ Fig.ȱ 16ȱVariationȱ ofȱ theȱ angularȱ positionȱ ofȱjointȱ (1)ȱ withȱ theȱinputȱvoltage,ȱtheȱinputȱvoltageȱvariesȱinȱamplitude.ȱ Time (sec.)

ȱ

Theȱ Captainȱ toolboxȱ providesȱ usefulȱ toolsȱ forȱ systemȱ modellingȱ andȱ modelȱ validityȱ parameters.ȱ Theȱ controlȱ strategyȱofȱtheȱStarlifterȱrobotȱisȱbasedȱonȱindividualȱjointȱ controlȱinȱwhichȱitȱcanȱbeȱconsideredȱasȱsingleȬinput,ȱu(k),ȱ singleȬoutput,ȱ y(k),ȱ (SISO),ȱ deterministicȱ system,ȱ Youngȱ etȱ alȱ (1998).ȱ Forȱ aȱ SISOȱ system,ȱ theȱ transferȱ functionȱ canȱ beȱdefinedȱinȱtermsȱofȱtheȱsampleȱnumberȱkȱas:ȱ ȱ

y (k )

B ( z 1 ) A( z 1 )

u (k ) ȱ

ȱ

(31)ȱ


z 1 ȱ isȱ theȱ backwardȱ shiftȱ operatorȱ i.e.ȱ z 1 y (k ) y (k 1) ȱandȱtheȱpolynomialsȱȱ

Whereȱ

A( z 1 ) 1 a1z 1 ... an z n ȱ

B ( z 1 ) Whereȱ

b1z 1 ... bm z m ȱ

a1 ,..., a n ȱ

andȱ

b1 ,..., bm ȱ

areȱ coefficientsȱ ofȱ

systemȱ denominatorȱ andȱ numeratorȱ polynomials,ȱ respectively.ȱȱ Theȱ parametersȱ ofȱ theȱ modelȱ canȱ beȱ estimatedȱ directlyȱ usingȱtheȱsimplifiedȱrefinedȱinstrumentalȱvariableȱ(SRIV)ȱ algorithm,ȱ Youngȱ (1985).ȱ Inȱ thisȱ algorithm,ȱ theȱ YICȱ (Youngȱ Identificationȱ Criterion),ȱ coupledȱ withȱ theȱ 2

coefficientȱ ofȱ determination, RT ,ȱ measureȱ ofȱ theȱ modelȱ fit,ȱ areȱ employedȱ toȱ determineȱ theȱ mostȱ suitableȱ modelȱ structure.ȱ Theȱ YICȱ providesȱ aȱ combinedȱ measureȱ ofȱ modelȱ fitȱ andȱ parametricȱ efficiency,ȱ withȱ largeȱ negativeȱ valuesȱindicatingȱaȱmodelȱwhichȱexplainsȱtheȱoutputȱdataȱ well,ȱ withoutȱ overȱ parameterizationȱ andȱ theȱ

RT2 ȱ valueȱ

reachingȱunity.ȱTaylorȱetȱalȱ(2000).ȱȱ Theȱ Captainȱ toolbox’ȱ functionsȱ determineȱ theȱ followingȱ parameters:ȱ

Byȱ convertingȱ theȱ characteristicsȱ polynomialȱ intoȱ zȬ operatorȱyields;ȱ

z 2 (0.0209 f 0 0.0209 k I 2.0002) z (1.0002 0.0209 f 0 ) ȱ ȱ ȱ (37)ȱ ȱ 6.5.4.5ȱTheȱPIPȱcontrolȱsimulationȱ Theȱ controlȱ structureȱ representedȱ byȱ equationȱ (36)ȱ isȱ similarȱ toȱ theȱ standardȱ digitalȱ PIȱ controlȱ howeverȱ theȱ manualȱ tuningȱ isȱ replacedȱ byȱ aȱ modelȬbasedȱ optimalȱ orȱ poleȱ placedȱ designȱ basedȱ onȱ theȱ identifiedȱ modelȱ representedȱbyȱequationȱ(35).ȱTheȱpipȱfunctionȱdevelopedȱ forȱtheȱPIPȱcontrolȱisȱusedȱtoȱcalculateȱtheȱgainsȱ k I and f 0 ȱ forȱselectedȱpoles.ȱSeveralȱgainsȱareȱobtainedȱforȱdifferentȱ polesȱ placements.ȱ Theȱ valuesȱ ofȱ theȱ gainsȱ areȱ examinedȱ usingȱ aȱ MATLABȱ SIMULINKȱ modelȱ developedȱ forȱ jointȱ (1)ȱ asȱ shownȱ inȱ Fig.ȱ 17.ȱ Theȱ bestȱ responseȱ hasȱ beenȱ obtainedȱ forȱ k I 9 ȱ and f 0 40 .ȱ Theȱ simulationȱ outputȱ andȱtheȱdrivingȱvalveȱsignalȱcorrespondingȱtoȱaȱunitȬstepȱ demandȱareȱillustratedȱinȱFig.ȱ18.ȱ ȱ

n, m, ai , bi , RT2 ȱ andȱ YIC.ȱ Forȱ mostȱ ofȱ theȱ

SISOȱlinearȱsystems,ȱtheȱtransferȱfunctionȱtakesȱtheȱform:ȱ ȱ ȱ

ȱ

(32)ȱ

ȱ 6.5.4.4ȱStarlifterȱjointȱ(1)ȱcontrollerȱdesignȱ Basedȱ onȱ theȱ dataȱ collectedȱ forȱ jointȱ (1),ȱ theȱ transferȱ functionȱcanȱbeȱwrittenȱinȱtheȱform:ȱ

1.2

(33)ȱ

TheȱNMSSȱvectorȱisȱgivenȱby:ȱ T

x(k ) [ y (k ) z (k )] ȱ

ȱ

(34)ȱ

ª 0.029 º ȱandȱ h « 0.029» ¬ ¼

>1 0@ ȱ

ȱ Theȱcontrolȱlawȱcanȱbeȱwrittenȱforȱjointȱ(1)ȱinȱtheȱform:ȱ

u (k )

f 0 y (k )

kI 1 z 1

0.6 0.4

{ yd (k ) y (k )} ȱ

ȱ

6 4 2 0

2

4

6

8

10

ȱ Fig.ȱ18ȱSimulationȱresultsȱ ȱ 6.6ȱEnvironmentalȱsensorsȱȱ Theȱ proposedȱ sensoryȱ systemȱ forȱ theȱ Starlifterȱ robotȱ isȱ identifiedȱ accordingȱ toȱ theȱ availableȱ sensors.ȱ Theȱ functionalȱdecompositionȱofȱtheȱsensoryȱsystemȱproposedȱ hereȱ isȱ shownȱ inȱ Fig.ȱ 19.ȱ Theȱ sensoryȱ systemȱ functionsȱ identifiedȱbelowȱare:ȱ 1. Endȱeffectorȱalignmentȱusingȱultrasonicȱsensorsȱ 2. Robotȱbaseȱpositioningȱusingȱaȱlaserȱscannerȱ 3. Taskȱ areaȱ monitoringȱ usingȱ aȱ simpleȱ visionȱ systemȱ No. of Samples

controlȱgainsȱrespectively.ȱȱ ȱ Usingȱ equationȱ (35)ȱ whichȱ describesȱ theȱ closedȱ loopȱ transferȱfunctionȱtheȱfollowingȱformȱisȱgiven:ȱ ȱ 0.0209 k I z 1

8

0

(35)ȱ

1 (0.0209 f 0 0.0209k I 2.0002) z 1 (1.0002 0.0209 f 0 ) z 2

0 10

-2

Whereȱ f 0 ȱ andȱ k I ,ȱ areȱ theȱ proportionalȱ andȱ integralȱ

y(k )

0.8

0.2

Forȱtheȱfirstȱorderȱsystemȱasȱjointȱ(1)ȱwhereȱn=1ȱandȱm=1ȱ thereȱareȱnoȱinputȱstatesȱinȱequationȱ(7.75).ȱTheȱassociatedȱ NMSSȱmodelȱcanȱbeȱdefinedȱaccordinglyȱas;ȱ ȱ

ª 1.0002 0º ,ȱ F « » g ¬ 1.0002 1¼

yd=1.0

1 Output, y

0.0209 z 1 u (k ) ȱ y (k ) 1 1.0002 z 1

ȱ ȱ Fig.ȱ17ȱSIMULINKȱblockȱdiagramȱofȱtheȱPIPȱcontrolȱ ȱ

Valve Signal, u, (V)

y(k )

b1 z 1 u (k ) ȱ 1 a1 z 1

yd ( k )

(36)ȱ

ȱ

493


Mostȱofȱtheȱpresentȱworkȱisȱconductedȱinȱorderȱtoȱachieveȱ theȱfollowingȱobjectives:ȱ 1. Interfaceȱwithȱtheȱsensorsȱ 2. Sensorȱ dataȱ acquisition,ȱ processingȱ andȱ visualizationȱ 3. Examinationȱ ofȱ theȱ performanceȱ ofȱ theȱ sensorsȱ forȱindoorȱandȱoutdoorȱenvironmentsȱ 4. Validationȱofȱtheȱsensorȱinformationȱ 5. Sensingȱstrategyȱplanningȱ Theȱfollowingȱsectionsȱdescribeȱinȱdetailȱtheȱlaserȱscanner,ȱ theȱultrasonicȱsensorsȱandȱtheȱvideoȱcameraȱsystem.ȱ ȱ

1. 2.

3. 4.

Theȱ operatorȱ placesȱ theȱ telescopicȱ boomȱ manuallyȱusingȱtheirȱbestȱjudgementȱ Theȱ sensoryȱ systemȱ isȱ thenȱ switchedȱ onȱ andȱ aȱ primaryȱscanningȱofȱtheȱsurroundingȱareaȱtakesȱ place.ȱ Theȱ operatorȱ thenȱ decidesȱ whichȱ directionȱ theȱ telescopicȱboomȱmoves.ȱ Byȱusingȱtheȱsafetyȱfieldsȱadjustmentȱfacility,ȱtheȱ sensoryȱsystemȱcanȱthenȱassistȱinȱnavigationȱandȱ theȱoperatorȱcanȱrelayȱonȱtheȱwarningȱissuedȱbyȱ theȱsystemȱinȱcaseȱofȱpossibleȱcollision.ȱ

ȱ Window

Starlifter Sensory System

Column

Level of the laser scanner

Corner Camera View Robot Base Positioning

End-effector Alignment

Robot Controller

Task area Monitoring

Laser scanner View

The Graphical User Interface

Fig.ȱ19ȱMainȱfunctionalȱdecompositionȱofȱtheȱStarlifterȱ sensoryȱsystemȱmoduleȱ ȱ 6.6.1ȱSensingȱstrategyȱusingȱtheȱlaserȱscannerȱ Theȱaimȱofȱusingȱtheȱlaserȱscanner,ȱinȱcombinationȱwithȱaȱ cameraȱ view,ȱ isȱ toȱ protectȱ theȱ robotȱ andȱ theȱ workingȱ environmentȱ fromȱ collisionȱ duringȱ robotȱpositioning–seeȱ Fig.ȱ 20,ȱ soȱ thatȱ theȱ robotȱ canȱ operateȱ correctlyȱ withinȱ itsȱ workingȱenvelope.ȱTheȱcameraȱviewȱgivesȱaȱ2Dȱimageȱofȱ theȱ workingȱ areaȱ andȱ theȱ laserȱ scannerȱ givesȱ theȱ thirdȱ dimensionȱasȱcanȱbeȱseenȱfromȱFig.ȱ21.ȱȱ ȱ Window

Corner

Working Area Path Position 2

Obstacle E.g. Column

Free Area

Out of range readings

ȱ

Position 2

Position 1

ȱ

ȱ Fig.ȱ21ȱTheȱlaserȱscanner/cameraȱassistedȱnavigationȱ

ȱ 6.6.2ȱSensingȱstrategyȱusingȱtheȱUC3000ȱsensorȱ Theȱ useȱ ofȱ ultrasonicȱ sensorsȱ forȱ alignmentȱ ofȱ theȱ endȬ effectorȱ isȱ justȱ aȱ smallȱ partȱ ofȱ aȱ globalȱ sensingȱ strategyȱ concerningȱ localisationȱ ofȱ theȱ robotȱ relativeȱ toȱ theȱ workingȱarea.ȱTheȱpositionȱstrategyȱincludes:ȱ 1. Appropriateȱ positioningȱ ofȱ theȱ robotȱ baseȱ relativeȱtoȱtheȱworkingȱareaȱ(Levelling)ȱ 2. Determinationȱofȱtheȱrobotȱbaseȱpositionȱrelativeȱ toȱ aȱ referenceȱ positionȱ inȱ theȱ workingȱ areaȱ (Referencing),ȱ 3. Positioningȱ ofȱ theȱ endȬeffectorȱ relativeȱ toȱ theȱ referenceȱposition.ȱ 4. Autoȱ alignmentȱ ofȱ theȱ endȬeffectorȱ forȱ correctȱ operationȱofȱtoolsȱ

ȱ RotoScan RS3

Position 1 The robot base ȱ Fig.ȱ20ȱTheȱlaserȱscannerȱsensingȱstrategyȱ ȱ Toȱ illustrateȱ theȱ navigationȱ strategyȱ usingȱ theȱ laserȱ scanner,ȱconsiderȱtheȱfollowingȱsituation:ȱtheȱrobotȱbaseȱisȱ attachedȱ toȱ theȱ endȱ ofȱ aȱ telescopicȱ boomȱ toȱ positionȱ theȱ robotȱ nearȱ itsȱ workingȱ areaȱ inȱ aȱ confinedȱ highȱ placeȱ asȱ seenȱfromȱtheȱviewsȱinȱFigs.ȱ20ȱandȱ21.ȱTheȱlaserȱscannerȱ isȱattachedȱtoȱtheȱrobotȱbaseȱandȱisȱequippedȱwithȱaȱvideoȱ camera.ȱTheȱscenarioȱofȱnavigationȱcanȱbeȱsummarisedȱasȱ follow:ȱ

494

Theȱ firstȱ andȱ theȱ secondȱ pointsȱ areȱ proposedȱ toȱ obtainȱ aȱ relationȱ betweenȱ theȱ robotȱ baseȱ coordinateȱ systemȱ ( xb , yb , z b )ȱ andȱ theȱ workingȱ areaȱ coordinateȱ systemȱ ( x w , y w , z w )ȱ(sayȱartificialȱlandmarks)ȱ–seeȱFigȱ22.ȱOnceȱ theȱaboveȱrelationȱhasȱbeenȱestablishedȱandȱtheȱrobotȱisȱinȱ itsȱ workingȱ envelope,ȱ theȱ endȬeffectorȱ canȱ beȱ positionedȱ inȱtheȱpreȬplannedȱpositionȱandȱorientationȱȱ TwoȱsensingȱstrategiesȱwereȱproposedȱbyȱPritschowȱetȱalȱ (1996).ȱ Theȱ firstȱ sensingȱ strategyȱ utilizesȱ aȱ laserȱ scannerȱ andȱ artificialȱ landmarksȱ forȱ absoluteȱ positioningȱ ofȱ theȱ roboticȱ platform.ȱ Theȱ secondȱ strategyȱ utilizesȱ aȱ simpleȱ sensingȱtechniqueȱusingȱtwoȱdistanceȱsensorsȱattachedȱtoȱ


theȱendȬeffector.ȱThisȱtechniqueȱenablesȱrobotȱpositioningȱ relativeȱ toȱ aȱ knownȱ referenceȱ position,ȱ howeverȱ itȱ requiresȱtheȱworkingȱareaȱtoȱconsistȱofȱtwoȱwallsȱformingȱ aȱ corner.ȱ Itȱ isȱ alsoȱ requiredȱ toȱ performȱ severalȱ measurementsȱ atȱ differentȱ positionsȱ toȱ obtainȱ accurateȱ results.ȱȱ Inȱtheȱcurrentȱwork,ȱweȱareȱgoingȱtoȱfocusȱonȱaȱsimpleȱuseȱ ofȱ ultrasonicȱ sensorsȱ forȱ alignmentȱ ofȱ theȱ endȬeffectorȱ perpendicularȱ toȱ theȱ workingȱ surfaceȱ toȱ enableȱ theȱ accurateȱdrillingȱofȱholesȱinȱconcrete.ȱȱ Theȱ currentȱ techniqueȱ isȱ validȱ providedȱ thatȱ theȱ followingȱassumptionsȱareȱmet:ȱ 1. Theȱ robotȱ baseȱ isȱ positionedȱ inȱ aȱ suitableȱ positionȱrelativeȱtoȱtheȱworkingȱareaȱ 2. Theȱ endȬeffectorȱ positionȱ andȱ orientationȱ areȱ knownȱ relativeȱ toȱ theȱ workingȱ areaȱ referenceȱ coordinatesȱ Theȱobjectiveȱofȱusingȱthisȱtechniqueȱisȱtoȱensureȱthatȱtheȱ estimatedȱorientationȱofȱtheȱendȬeffectorȱisȱaccurate.ȱȱ

ȱ Wall

zb

End-effector plate

d1

xe

d3

ye

ze

2s

d4 Ultrasonic sensors

d2

'1

'2 Target area

d\

'1

d1 d 2

'2

d3 d 4

dT

2s

2s

ȱ ȱ Fig.ȱ23ȱSensorsȱarrangementȱforȱtheȱendȬeffectorȱ alignmentȱ ȱ ȱ 3000

xe

ze

yw

End-effector coordinates

xb

xw

yb

Base coordinates

World coordinates (Working area)

ȱ

ȱ Fig.ȱ22ȱCoordinateȱsystemsȱdefinitionȱforȱtheȱglobalȱ strategyȱ ȱ 6.6.2.1ȱAlignmentȱtechniqueȱdescriptionȱ Fourȱ ultrasonicȱ sensorsȱ areȱ usedȱ forȱ theȱ alignmentȱ procedureȱ–seeȱFig.ȱ23.ȱTheȱfourȱsensorsȱareȱattachedȱtoȱaȱ sensingȱ headȱ thatȱ canȱ beȱ usedȱ togetherȱ withȱ theȱ automaticȱ toolȱ changer,ȱ i.e.ȱ theȱ sensingȱ headȱ isȱ firstȱ attachedȱ toȱ theȱ endȬeffectorȱ forȱ alignmentȱ theȱ sensingȱ headȱ canȱ beȱ thenȱ replacedȱ automaticallyȱ byȱ theȱ appropriateȱ tool.ȱ Fourȱ distancesȱ canȱ beȱ measuredȱ atȱ aȱ singleȱpositionȱusingȱtheȱultrasonicȱsensorsȱ d1 , d 2 , d 3 ȱandȱ

d 4 .ȱ Usingȱ theȱ followingȱ relationsȱ theȱ differentialȱ yawȱ andȱpitchȱanglesȱcanȱbeȱcalculated:ȱ Theȱdifferentialȱpitch,ȱ dT differentialȱyawȱ d\

tan 1 (

tan 1 (

'1 ) ȱandȱtheȱ 2s

'2 )ȱ 2s

1800

1200

600

0 0

600

1200

1800

2400

3000

ȱ

Actual distance (mm)

Fig.ȱ24ȱCalibrationȱcurveȱforȱtheȱUC3000ȱsensorȱȱ ȱ ȱ ȱ 2600 Object 1 (Ceiling)

Sesnor readings (mm)

ye

Sensor readings (mm)

2400 zw

2400

Object 2

2200

Whereȱ 2 s ȱisȱtheȱlengthȱofȱtheȱendȬeffectorȱplateȱside,ȱ '1 ȱ andȱ ' 2 ȱareȱtheȱdifferenceȱinȱtheȱsensorsȱreadings.ȱ Theȱ valuesȱ ofȱ theȱ differentialȱ orientationsȱ dT ȱ andȱ d\ ȱ canȱbeȱthenȱusedȱtoȱadjustȱtheȱendȬeffectorȱorientation.ȱItȱ isȱ moreȱ economicalȱ toȱ useȱ oneȱ sensorȱ toȱ performȱ thisȱ technique.ȱȱ

2000 0

10

20

30 Time (s)

40

50

60

ȱ

Fig.ȱ25ȱSensorȱoutputȱ

495


Thisȱ canȱ beȱ doneȱ byȱ takingȱ aȱ measurementȱ atȱ aȱ specificȱ positionȱandȱthenȱrotatingȱtheȱendȬeffectorȱinȱincrementsȱ ofȱ90oȱandȱtakingȱfurtherȱmeasurements.ȱȱ Severalȱtestsȱhaveȱbeenȱconductedȱtoȱevaluateȱtheȱsensorȱ performance.ȱAȱcalibrationȱtestȱisȱcarriedȱoutȱtoȱverifyȱtheȱ correctnessȱ ofȱ theȱ sensorȱ readingsȱ andȱ aȱ satisfactoryȱ calibrationȱcurveȱisȱobtainedȱasȱshownȱinȱFig.ȱ24.ȱSeveralȱ readingsȱ wereȱ obtainedȱ forȱ differentȱ positionsȱ ofȱ theȱ objectȱ relativeȱ toȱ theȱ sensorȬȱ seeȱ Fig.ȱ 25.ȱ Theȱ sensorȱ readingȱvariationȱwithȱtimeȱisȱshownȱinȱFig.ȱ26.ȱFromȱthisȱ figure,ȱ itȱ isȱ clearȱ that,ȱ stableȱ readingsȱ ofȱ theȱ objectȱ positionȱ haveȱ beenȱ obtainedȱ ȱ Theȱ standardȱ deviationȱ ofȱ theȱ readingsȱ rangingȱ betweenȱ 0ȱ andȱ 0.34ȱ whileȱ theȱ standardȱerrorȱofȱmeanȱrangesȱfromȱ0ȱtoȱ0.004,ȱtheȱlowestȱ valuesȱforȱtheȱfarȱobjects.ȱȱ Aȱsimpleȱdynamicȱtestȱisȱcarriedȱoutȱtoȱobtainȱtheȱsensorȱ responseȱtoȱaȱmovingȱobjectȱattachedȱtoȱaȱrailȱandȱfallingȱ freelyȱ underȱ theȱ actionȱ ofȱ itsȱ weight.ȱ Theȱ readingsȱ recordedȱareȱshownȱinȱFig.ȱ27ȱinȱwhichȱsmoothȱvariationȱ ofȱ theȱ objectȱ positionȱ withȱ timeȱ isȱ observedȱ forȱ theȱ twoȱ testȱtrials.ȱȱ ȱ ȱ 2000

Sesnor readings(mm)

1600

1200

800

400

0 0

10

20

30

40

ȱ Fig.ȱ26ȱVariationȱofȱtheȱUC3000ȱsensorȱreadingsȱwithȱtimeȱ Time (s)

ȱ ȱ 1000

Sesnor readings (mm)

800

600

400

200 0

10

20 Time (s)

Fig.ȱ27ȱSensorȱreadingsȱobtainedȱforȱaȱmovingȱobjectȱ

496

30

ȱ

6.6.2.2ȱTestsȱconclusionsȱ 1.

Excellentȱ readingsȱ canȱ beȱ obtainedȱ fromȱ theȱ sensorsȱ whenȱ objectsȱ areȱ insideȱ theȱ sensorȱ rangeȱ coneȱ withȱ suitableȱenvironmentalȱconditions.ȱ

2.

ȱInclinedȱobjectsȱmoreȱthanȱ r 17 o ȱgiveȱfalseȱorȱoutȱofȱ rangeȱresponse.ȱ Multipleȱ objectsȱ canȱ beȱ detectedȱ byȱ theȱ sensorȱ andȱ theȱ responseȱ fromȱ theȱ sensorȱ isȱ aȱ fluctuatingȱ signalȱ showingȱtheȱpossibleȱpositionȱofȱtheȱobjects.ȱ Theȱsensorȱcanȱbeȱusedȱasȱaȱnavigationȱsensorȱasȱtheȱ endȬeffectorȱapproachesȱtheȱtargetȱareaȱ ȱGenerallyȱ speaking,ȱ theȱ sensorȱ showsȱ goodȱ reliabilityȱ forȱ indoorȱ conditionsȱ butȱ moreȱ testsȱ areȱ requiredȱ toȱ examineȱ theȱ sensorȱ performanceȱ forȱ outdoorȱconditions.ȱȱ

3.

4. 5.

ȱ 6.6.3ȱVideoȱcamerasȱȱ Taskȱmonitoringȱbyȱtheȱsystemȱoperatorȱrequiresȱtheȱuseȱ ofȱ videoȱ camerasȱ placedȱ atȱ differentȱ locationsȱ inȱ theȱ workingȱ area.ȱ Theȱ useȱ ofȱ videoȱ camerasȱ couldȱ beȱ forȱ monitoringȱ onlyȱ orȱ beȱ usefulȱ inȱ extractingȱ environmentȱ featuresȱbyȱusingȱsimpleȱimageȱprocessingȱfacilitiesȱsuchȱ asȱdimensioningȱofȱtheȱworkȱarea.ȱVideoȱcameraȱsystemsȱ areȱ availableȱ asȱ offȬtheȬshelfȱ componentsȱ however;ȱ theȱ selectionȱ ofȱ aȱ suitableȱ cameraȱ forȱ constructionȱ activityȱ monitoringȱ shouldȱ considerȱ theȱ specialȱ natureȱ ofȱ theȱ workingȱenvironment.ȱȱ Inȱ theȱ presentȱ work,ȱ theȱ crucialȱ issueȱ inȱ selectionȱ ofȱ aȱ cameraȱ systemȱ isȱ itsȱ interfaceȱ withȱ theȱ systemȱ userȱ interface,ȱinȱadditionȱtoȱotherȱfactorsȱrelatedȱtoȱtheȱnatureȱ ofȱ theȱ workingȱ environmentȱ whichȱ requiresȱ aȱ durableȱ andȱ reliableȱ cameraȱ system.ȱ Anȱ analogueȱ videoȱ cardȱ isȱ usedȱinȱconjunctionȱwithȱanȱordinaryȱsingleȱfocusȱcameraȱ toȱ developȱ aȱ monitoringȱ systemȱ integratedȱ withȱ theȱ sensoryȱ systemȱ discussedȱ above.ȱ Aȱ standȱ aloneȱ userȱ interfaceȱ hasȱ beenȱ developedȱ withinȱ LabVIEWȱ toȱ interfaceȱ theȱ videoȱ card.ȱ Thisȱ userȱ interfaceȱ isȱ basedȱ onȱ theȱ useȱ ofȱ ActiveXȱ componentsȱ whichȱ includesȱ severalȱ functionsȱforȱvideoȱrecording,ȱframeȱgrabbingȱinȱadditionȱ toȱ imageȱ fileȱ manipulationȱ functions.ȱ Imageȱ acquisitionȱ functionsȱ (IMAQ)ȱ builtȱ inȱ LabVIEWȱ areȱ usedȱ forȱ frameȱ capturing,ȱ saving,ȱ andȱ simpleȱ imageȱ processingȱ suchȱ asȱ zoomȬinȱandȱzoomȬout.ȱTheȱuseȱofȱtheseȱfunctionsȱcanȱbeȱ extendedȱ toȱ addȱ otherȱ facilitiesȱ suchȱ asȱ onȬscreenȱ measurementsȱ toȱ extractȱ dimensionsȱ andȱ featuresȱ ofȱ theȱ workingȱarea.ȱȱ Asȱmentionedȱabove,ȱitȱisȱrequiredȱtoȱuseȱmoreȱthanȱoneȱ cameraȱ forȱ taskȱ areaȱ monitoring.ȱ Analogueȱ videoȱ cardsȱ provideȱanȱinterfaceȱwithȱonlyȱoneȱcameraȱperȱcardȱwhichȱ makesȱ theȱ systemȱ bulky.ȱ Firewireȱ technologyȱ providesȱ cardsȱ withȱ multipleȱ cameraȱ inputs,ȱ highȱ imageȱ qualityȱ andȱ easyȱ interfacing.ȱ Itȱ isȱ howeverȱ expensiveȱ comparedȱ toȱtheȱanalogueȱcards.ȱȱ ȱ 6.6.4ȱTheȱsensingȱheadȱȱ TheȱuseȱofȱanȱultrasonicȱsensorȱforȱendȬeffectorȱalignmentȱ ledȱ toȱ theȱ developmentȱ ofȱ aȱ completeȱ sensingȱ headȱ thatȱ


canȱbeȱtemporarilyȱinstalledȱatȱtheȱendȬeffectorȱduringȱtheȱ alignmentȱ processȱ andȱ thenȱ uninstalledȱ andȱ placedȱ inȱ aȱ safeȱ andȱ handyȱ placeȱ onȱ theȱ mobileȱ platform.ȱ Thisȱ sensingȱheadȱcouldȱincludeȱtheȱfollowingȱsensors:ȱ 1. Fourȱultrasonicȱsensorsȱ 2. Videoȱcameraȱ 3. Rebarȱlocatorȱforȱreinforcementȱbarsȱ(ifȱrequired)ȱ ȱ Theȱbasicȱideaȱisȱtoȱplaceȱtheȱsensingȱheadȱonȱoneȱofȱtheȱ toolȱchangerȱdocksȱsoȱthatȱtheȱendȬeffectorȱcanȱpickȱitȱupȱ asȱ required.ȱ Twoȱ sensingȱ tasksȱ areȱ identifiedȱ usingȱ theȱ sensingȱ head,ȱ firstly,ȱ alignmentȱ ofȱ theȱ endȬeffectorȱ relativeȱ toȱ theȱ taskȱ areaȱ andȱ secondly,ȱ scanningȱ theȱ taskȱ areaȱ forȱ reinforcementȱ usingȱ aȱ rebarȱ locatorȱ toȱ avoidȱ drillingȱit.ȱTheȱsecondȱsensingȱtaskȱisȱbeyondȱtheȱscopeȱofȱ theȱpresentȱwork.ȱȱ Theȱsensingȱheadȱisȱequippedȱwithȱaȱvideoȱcameraȱwhichȱ isȱ usedȱ toȱ assistȱ theȱ ultrasonicȱ sensorsȱ inȱ extractingȱ theȱ workingȱareaȱfeaturesȱduringȱtheȱalignmentȱprocess.ȱThisȱ cameraȱshouldȱhaveȱaȱwideȱfocusȱlensȱtoȱprovideȱaȱbiggerȱ rangeȱthanȱtheȱultrasonicȱsensors.–seeȱFig.ȱ28.ȱ

ȱ

Camera View

Sensing Head Ultrasonic sensors Cones Working Area

ȱ Fig.ȱ28ȱTheȱsensingȱheadȱ ȱ 6.7ȱSoftwareȱDevelopmentȱȱ Softwareȱ developmentȱ representsȱ aȱ substantialȱ partȱ ofȱ aȱ roboticȱ systemȱ developmentȱ process,ȱ andȱ theȱ bulkȱ ofȱ systemȱ developmentȱ problemsȱ areȱ oftenȱ attributedȱ toȱ softwareȱproblems.ȱMostȱofȱtheȱcomponentsȱinvolvedȱinȱaȱ roboticȱ systemȱ requireȱ atȱ leastȱ oneȱ pieceȱ ofȱ softwareȱ forȱ controlȱ orȱ dataȱ transfer.ȱ Theȱ adoptionȱ ofȱ anȱ offȬtheȬshelfȱ componentsȱ strategyȱ acceleratesȱ theȱ hardwareȱ developmentȱ process,ȱ howeverȱ itȱ canȱ resultȱ inȱ softwareȱ problemsȱ associatedȱ withȱ integrationȱ andȱ interfacing.ȱ Alternatively,ȱ theȱ useȱ ofȱ speciallyȱ developedȱ hardwareȱ componentsȱ takesȱ intoȱ accountȱ interfacesȱ andȱ theȱ finalȱ integrationȱ process,ȱ butȱ developmentȱ timeȱ andȱ costsȱ cannotȱ beȱ controlled.ȱ Asȱ aȱ compromise,ȱ theȱ problemsȱ associatedȱ withȱ theȱ useȱ ofȱ offȬtheȬshelfȱ componentsȱ canȱ beȱ reducedȱ byȱ theȱ useȱ ofȱ powerfulȱ softwareȱ toȱ handleȱ interfacingȱproblems.ȱȱ Inȱ theȱ presentȱ work,ȱ effortsȱ haveȱ beenȱ madeȱ toȱ achieveȱ theȱ objectiveȱ ofȱ rapidȱ softwareȱ development.ȱ Threeȱ conceptsȱ areȱ adoptedȱ hereȬinȱ toȱ achieveȱ thisȱ objective.ȱ Theseȱ conceptsȱ areȱ architecturalȱ design,ȱ modularisationȱ andȱprototyping.ȱAsȱmentionedȱinȱsectionȱ4ȱtheȱprinciplesȱ ofȱ systemsȱ engineeringȱ allowsȱ forȱ theȱ useȱ ofȱ theseȱ

concepts,ȱ howeverȱ theyȱ areȱ usedȱ inȱ aȱ differentȱ wayȱ forȱ softwareȱdevelopment.ȱȱ Softwareȱ developmentȱ asȱ aȱ substantialȱ partȱ ofȱ theȱ developmentȱprocessȱreceivesȱaȱpackageȱofȱrequirementsȱ extractedȱ fromȱ theȱ systemȱ requirementȱ document.ȱ Thisȱ packageȱcanȱbeȱthenȱdecomposedȱintoȱmodulesȱandȱeachȱ moduleȱ canȱ followȱ theȱ softwareȱ developmentȱ modelȱ presentedȱ byȱ Sewardȱ andȱ Ziedȱ 2004.ȱ Howeverȱ itȱ isȱ importantȱtoȱconstructȱaȱglobalȱarchitecturalȱdesignȱforȱallȱ modulesȱtoȱgiveȱguidelinesȱtoȱtheȱfinalȱintegrationȱprocessȱ ofȱ theȱ softwareȱ package.ȱ Constructingȱ theȱ architecturalȱ designȱ providesȱ aȱ clearȱ imageȱ ofȱ theȱ requiredȱ softwareȱ componentsȱfacingȱtheȱsystemȱdeveloper.ȱAsȱcanȱbeȱseenȱ fromȱ thisȱ architectureȱ differentȱ componentsȱ andȱ interfacesȱ areȱ usedȱ toȱ satisfyȱ theȱ systemȱ requirements.ȱ Someȱ componentsȱ comeȱ withȱ serviceȱ software,ȱ whichȱ needsȱmodification,ȱorȱadaptationȱandȱothersȱrequireȱtheȱ developmentȱ ofȱ newȱ software.ȱ Decompositionȱ ofȱ theȱ componentȱ softwareȱ intoȱ modulesȱ allowsȱ individualȱ testingȱ forȱ functionality.ȱ Thisȱ decompositionȱ easesȱ theȱ developmentȱ processȱ butȱ itȱ putsȱ muchȱ loadȱ onȱ theȱ integrationȱprocess.ȱȱ Theȱ useȱ ofȱ graphicalȱ programmingȱ allowsȱ forȱ theȱ applicationȱ ofȱ theȱ aboveȬmentionedȱ concepts.ȱ Graphicalȱ programmingȱisȱmodularȱinȱnature,ȱwhichȱinȱturnȱallowsȱ forȱbuildingȱaȱhierarchyȱofȱtheȱdevelopedȱsoftware,ȱwhichȱ representsȱ theȱ initialȱ decompositionȱ illustratedȱ inȱ theȱ globalȱ architecturalȱ design.ȱ Itȱ alsoȱ allowsȱ theȱ buildingȱ ofȱ applicationsȱ fromȱ readyȬmadeȱ componentsȱ thatȱ canȱ beȱ usedȱtoȱverifyȱtheȱfunctionalityȱofȱaȱprogramȱi.e.ȱbuildingȱ aȱprototype.ȱHowever,ȱthisȱprototypeȱcanȱbeȱreusedȱinȱtheȱ finalȱsoftwareȱdevelopment.ȱȱ Designingȱanȱattractiveȱfunctionalȱgraphicalȱuserȱinterfaceȱ (GUI)ȱ addsȱ extraȱ valueȱ toȱ theȱ softwareȱ fromȱ theȱ userȱ pointȱ ofȱ viewȱ andȱ graphicalȱ programmingȱ showsȱ greatȱ capabilitiesȱinȱthisȱregard.ȱUsingȱgraphicalȱprogrammingȱ canȱalsoȱsatisfyȱotherȱconcernsȱsuchȱasȱkeepingȱcontrolȱofȱ theȱdevelopmentȱtimeȱandȱcosts.ȱȱ Theȱ detailedȱ archtectureȱ ofȱ theȱ onȬboardȱ systemȱ andȱ theȱ offȬlineȱ simulationȱ wereȱ presentedȱ inȱ previousȱ work,ȱ SewardȱandȱZiedȱ2004.ȱȱ Accordingȱ theȱ softwareȱ architectureȱ forȱ theȱ Starlifterȱ system,ȱ theȱ onȬboardȱ systemȱ softwareȱ componentsȱ suchȱ asȱ theȱ robotȱ controllerȱ andȱ externalȱ sensorsȱ wereȱ developedȱasȱwellȱasȱforȱtheȱoffȬlineȱsimulationȱsystem.ȱ Fig.ȱ 29ȱ &ȱ 30ȱ showȱ theȱ frontȱ panelȱ forȱ Starlifterȱ robotȱ controllerȱ andȱ externalȱ sensorsȱ GUIȱ integratedȱ frontȱ panel.ȱ Integrationȱofȱdifferentȱsoftwareȱcomponentsȱrepresentsȱaȱ substantialȱ partȱ ofȱ theȱ softwareȱ developmentȱ process.ȱ However,ȱ theȱ useȱ ofȱ LabVIEWȱ makesȱ theȱ integrationȱ processȱ easierȱ whenȱ usedȱ inȱ conjunctionȱ withȱ theȱ architecturalȱ designȱ explainedȱ previously.ȱ Aȱ majorȱ stepȱ thatȱ shouldȱ beȱ doneȱ beforeȱ theȱ integrationȱ processȱ startsȱ isȱ softwareȱ componentsȱ testing.ȱ Testingȱ andȱ verificationȱ atȱ theȱ lowestȱ levelȱ isȱ theȱ mostȱ feasibleȱ becauseȱ itȱ avoidsȱ accumulativeȱ errorsȱ Stevensȱ etȱ alȱ (1998).ȱ Graphicalȱ

497


programmingȱprovidesȱfacilitiesȱforȱeasyȱintegrationȱsuchȱ asȱ polymorphismȱ inȱ dataȱ types,ȱ whichȱ enablesȱ theȱ handlingȱofȱseveralȱdataȱtypesȱwithinȱaȱsingleȱVIȱwithoutȱ theȱneedȱforȱdataȱtypeȱdeclaration.ȱ ȱ ȱ

ȱ Fig.ȱ 29ȱ Starlifterȱ controllerȱ GUIȱ withȱ Workspaceȱ simulationȱpackageȱinterfaceȱȱ ȱ

ȱ Fig.ȱ30ȱStarlifterȱexternalȱsensorȱintgratedȱGUIȱȱ ȱ ȱ

6.8ȱSystemȱtesting,ȱintegrationȱandȱverificationȱȱ Theȱ developedȱ componentsȱ developedȱ soȱ farȱ wereȱ individuallyȱ testedȱ forȱ functionalityȱ andȱ performance.ȱ Integrationȱ ofȱ theȱ systemȱ componentsȱ isȱ performedȱ throughȱ software.ȱ Forȱ example,ȱ externalȱ sensorsȱ areȱ integratedȱ inȱ oneȱ moduleȱ andȱ testȱ forȱ functionality.ȱ Theȱ intgrationȱ ofȱ theȱ otherȱ componentsȱ canȱ beȱ doneȱ inȱ theȱ sameȱ way.ȱ Thisȱ methodȱ willȱ beȱ verifiedȱ byȱ fieldȱ testsȱ ofȱ theȱintegratedȱsystem.ȱ ȱ

7.ȱConclusionsȱȱ Thisȱ workȱ focusesȱ onȱ theȱ developmentȱ ofȱ processesȱ andȱ practicesȱ forȱ roboticȱ systemsȱ forȱ constructionȱ activatesȱ whereȱ humanȱ interventionȱ isȱ requiredȱ toȱ beȱ minimized.ȱ Safetyȱ issuesȱ alertȱ decisionȬmakersȱ toȱ investigateȱ theȱ feasibilityȱofȱusingȱroboticȱsystemsȱforȱsuchȱenvironmentsȱ toȱ reduceȱ hazardȱ risks.ȱ Theȱ natureȱ ofȱ constructionȱ sitesȱ andȱtheȱnatureȱofȱtasksȱinvolvedȱinȱconstructionȱactivitiesȱ justifiesȱ theseȱ sitesȱ beingȱ consideredȱ asȱ hazardousȱ

498

environments.ȱ Althoughȱ strategicȱ researchȱ onȱ theȱ useȱ ofȱ robotsȱ inȱ theȱ constructionȱ industryȱ hasȱ beenȱ underwayȱ forȱsomeȱtime,ȱlittleȱhasȱbeenȱactuallyȱimplementedȱowingȱ toȱ severalȱ barriers.ȱ Theseȱ barriersȱ comeȱ fromȱ firstly,ȱ theȱ lackȱofȱfeasibilityȱanalysesȱwhichȱjustifyȱtheȱuseȱofȱrobotsȱ inȱ theȱ constructionȱ industryȱ andȱ secondly,ȱ theȱ lackȱ ofȱ methodologiesȱ andȱ toolsȱ forȱ rapidȱ developmentȱ ofȱ sophisticatedȱ roboticȱ systemsȱ requiredȱ forȱ handlingȱ constructionȱtasks.ȱȱ Theȱmajorȱresearchȱquestionsȱaddressedȱwere:ȱ Howȱcanȱtheȱuseȱofȱadvancedȱautomationȱandȱroboticsȱbeȱ justifiedȱforȱuseȱinȱconstructionȱactivities?ȱ Howȱ canȱ suchȱ systemsȱ beȱ developedȱ inȱ aȱ modularȱ andȱ economicȱ fashionȱ forȱ aȱ wideȱ rangeȱ ofȱ differentȱ applications?ȱ Howȱcanȱsuchȱsystemsȱbeȱproperlyȱincorporatedȱintoȱtheȱ businessȱprocessesȱofȱconstructionȱcompanies?ȱ Consequentlyȱtwoȱprimaryȱobjectivesȱareȱidentifiedȱinȱtheȱ presentȱwork.ȱTheȱfirstȱobjectiveȱisȱtheȱinvestigationȱofȱtheȱ feasibilityȱ ofȱ usingȱ robotsȱ forȱ constructionȱ activities.ȱ Theȱ secondȱobjectiveȱisȱconcernedȱwithȱtheȱengineeringȱofȱtheȱ developmentȱprocessȱforȱsuchȱrobots.ȱ Forȱ theȱ firstȱ objective,ȱ aȱ feasibilityȱ analysisȱ modelȱ isȱ designedȱ andȱ appliedȱ toȱ particularȱ caseȱ studiesȱ inȱ orderȱ toȱ justifyȱ theȱ useȱ ofȱ robotsȱ inȱ thoseȱ activities.ȱ Theȱ feasibilityȱ analysisȱ modelȱ consistsȱ ofȱ stagesȱ whichȱ addressȱtheȱproblemȱfromȱdifferentȱviewpoints.ȱThroughȱ theȱ differentȱ stagesȱ ofȱ theȱ modelȱ severalȱ methodologiesȱ andȱtoolsȱareȱidentifiedȱandȱusedȱtoȱaccomplishȱtheȱtasksȱ involvedȱinȱtheȱfeasibilityȱanalysisȱmodel.ȱȱ TheȱStarlifterȱrobot,ȱtheȱfirstȱrobotȱinȱtheȱworldȱespeciallyȱ designedȱ forȱ heavyȱ toolȱ deploymentȱ inȱ hazardousȱ environments,ȱ isȱ usedȱ asȱ aȱ roboticȱ automationȱ solutionȱ forȱtheȱcaseȱstudiesȱpresentedȱinȱthisȱthesis.ȱFromȱtheȱcaseȱ studiesȱ presentedȱ inȱ thisȱ work,ȱ theȱ proposedȱ modelȱ isȱ foundȱ toȱ beȱ practicalȱ andȱ comprehensiveȱ becauseȱ itȱ handlesȱtheȱfeasibilityȱanalysisȱfromȱdifferentȱviewpointsȱ usingȱ simpleȱ andȱ systematicȱ methodologies.ȱ Moreȱ caseȱ studiesȱand/orȱroboticȱsystemsȱareȱrequiredȱtoȱjustifyȱtheȱ robustnessȱofȱtheȱproposedȱmodel.ȱȱ Forȱ theȱ secondȱ objective,ȱ manyȱ developmentȱ modelsȱ areȱ investigatedȱpriorȱtoȱtheȱselectionȱofȱaȱsuitableȱmodelȱforȱ theȱ developmentȱ ofȱ roboticȱ systemsȱ forȱ constructionȱ activities.ȱ Principlesȱ ofȱ Systemsȱ Engineeringȱ areȱ investigatedȱandȱfoundȱtoȱmatchȱtheȱrequirementsȱforȱtheȱ developmentȱ ofȱ roboticȱ systems.ȱ Oneȱ ofȱ theȱ proposedȱ developmentȱ modelsȱ isȱ theȱ sequentialȱ developmentȱ modelȱ whichȱ isȱ usedȱ asȱ aȱ basisȱ forȱ theȱ Starlifterȱ developmentȱ process.ȱ Functionalȱ decomposition,ȱ modularisationȱ andȱ architecturalȱ designȱ areȱ usefulȱ conceptsȱusedȱinȱtheȱpresentȱworkȱforȱtheȱdevelopmentȱofȱ theȱ Starlifterȱ roboticȱ systemȱ components.ȱ Aȱ completeȱ functionalȱ decompositionȱ andȱ architecturalȱ designȱ ofȱ Starlifterȱ isȱ presentedȱ forȱ bothȱ offȬlineȱ andȱ onboardȱ systems.ȱȱ Aȱ detailedȱ explanationȱ andȱ discussionȱ ofȱ theȱ developmentȱ processȱ isȱ presentedȱ forȱ allȱ systems.ȱ


Graphicalȱ simulationȱ isȱ usedȱ inȱ manyȱ aspectsȱ ofȱ theȱ developmentȱprocessȱsuchȱasȱsystemȱdesignȱandȱtaskȱcostȱ estimation.ȱ Graphicalȱ programmingȱ wasȱ foundȱ toȱ beȱ anȱ appropriateȱ softwareȱ developmentȱ environmentȱ forȱ constructionȱ robots.ȱ LabVIEWȱ isȱ selectedȱ asȱ theȱ coreȱ softwareȱ developmentȱ environment.ȱ Comprehensiveȱ softwareȱ architectureȱ isȱ presentedȱ forȱ bothȱ offȬlineȱ andȱ onȬboardȱ systems.ȱ Aȱ detailedȱ designȱ ofȱ theȱ systemȱ controllerȱ isȱ presentedȱ forȱ bothȱ theȱ kinematicsȱ controllerȱ (highȱ level)ȱ andȱ theȱ servoȬlevelȱ controllerȱ (Lowȱ level).ȱ Aȱ dataȬbasedȱ modellingȱ techniqueȱ isȱ usedȱ toȱ modelȱ theȱ robotȱ jointsȱ forȱ theȱ lowȱ levelȱ controlȱ design.ȱ Theȱ ProportionalȬIntegralȬPlusȱ (PIP)ȱ controlȱ philosophyȱ isȱ usedȱtoȱdesignȱtheȱcontrollerȱforȱoneȱofȱtheȱjointsȱinȱorderȱ toȱ demonstrateȱ theȱ applicabilityȱ ofȱ thisȱ approachȱ forȱ dynamicȱ systems.ȱ Threeȱ typesȱ ofȱ sensorȱ areȱ usedȱ forȱ theȱ systemȱnavigation,ȱendȬeffectorȱpositioningȱandȱtaskȱareaȱ monitoring.ȱ Aȱ detailedȱ explanationȱ ofȱ theȱ theoryȱ ofȱ operation,ȱ sensingȱ strategyȱ andȱ interfaceȱ techniquesȱ areȱ presentedȱforȱeachȱsensor.ȱIntegrationȱofȱtheȱthreeȱsensorsȱ withȱtheȱsystemȱuserȱinterfaceȱisȱpresentedȱinȱdetail.ȱȱ ȱ 8.ȱAcknowledgementsȱȱ Iȱ wouldȱ likeȱ toȱ expressȱ myȱ deepestȱ thanksȱ toȱ Professorȱ DerekȱSewardȱforȱhisȱmajorȱcontributionȱthroughoutȱthisȱ work.ȱ Specialȱ thanksȱ toȱ theȱ managingȱ directorȱ ofȱ Constructionȱ Roboticsȱ Ltd,ȱ Mrȱ Johnȱ Riehlȱ forȱ hisȱ contributionȱandȱsponsorshipȱofȱthisȱwork.ȱȱ ȱ ȱ 9.ȱReferencesȱȱ Gu,ȱ J.ȱ Taylor,ȱ J.ȱ andȱ Seward,ȱ D.,ȱ 2004.ȱ ProportionalȬ IntegralȬPlusȱ Controlȱ ofȱ anȱ Intelligentȱ Excavator,ȱ ComputerȬAidedȱ Civilȱ andȱ Infrastructureȱ EngineeringȱVȱ19ȱpp16–27ȱ Hass,ȱC.ȱT.ȱandȱHsieh,ȱT.ȱY.,ȱ1993.ȱPerformanceȱevaluationȱ modelȱforȱconstructionȱmanipulators,ȱProceedingsȱofȱ theȱ 10thȱ ISARC,ȱ ppȱ 301Ȭ308,ȱ 24Ȭ26ȱ May,ȱ Houston,ȱ Texas,ȱUSA.ȱ Kangari,ȱ R.ȱ andȱ Halpin,ȱ D.ȱ W.,ȱ 1990.ȱ Identificationȱ ofȱ factorsȱ influencingȱ implementationȱ ofȱ constructionȱ robotics.,ȱ Journalȱ ofȱ Constructionȱ Managementȱ andȱ Economics,ȱV8,ȱppȱ89Ȭ104.ȱ Kangary,ȱ R.ȱ andȱ Gregory,ȱ R.,ȱ 1997.ȱ Feasibilityȱ ofȱ automatingȱ military’sȱ environmentalȱ operations,ȱ AutomationȱinȱConstruction,ȱVȱ5,ȱpp.ȱ459Ȭ468.ȱ Lees,ȱM.ȱJ.,ȱTaylor,ȱC.ȱJ.,ȱYoung,ȱP.ȱC.ȱandȱChotai,ȱA.,ȱ1998.ȱ Modellingȱ andȱ PIPȱ controlȱ designȱ forȱ openȬtopȱ chambers,ȱ Controlȱ Engineeringȱ Practice,ȱ Vȱ 6ȱ pp.ȱ 1209Ȭ1216.ȱ Leuze,ȱ 2001.ȱ RotoScan,ȱ Userȱ manual,ȱ Luezeȱ Electronics,ȱ www.leuze.ch/deutsch/download/dat/rs3.pdfȱȱ Mckerrow,ȱP.ȱJ.,ȱ1991,ȱIntroductionȱtoȱRobotics,ȱAddisonȬ WesleyȱPublishingȱCompany,ȱ Neil,ȱ C.ȱ Salomonsson,ȱ G.ȱ andȱ Skibniewski,ȱ M.,ȱ 1993.ȱ Robotȱ implementationȱ Decsionsȱ inȱ Australianȱ

constructionȱ industry,ȱ ISARCȱ 10,ȱ Houston,ȱ Texas,ȱ USA,ȱpp.ȱ133Ȭ140.ȱ Paul,ȱ R.,ȱ 1981.ȱ Robotȱ manipulator:ȱ Mathematics,ȱ programmingȱ andȱ control,ȱ MITȱ Press,ȱ Cambridge,ȱ Mass.ȱ Pritschow,ȱG.,ȱKurz,ȱJ.ȱMccormac,ȱS.ȱE.ȱandȱDalacker,ȱM.,ȱ 1996.ȱ Practicalȱ sensorȱ strategiesȱ forȱ onȬsiteȱ positioningȱofȱmobileȱbricklayingȱrobot,ȱProceedingsȱ ofȱ theȱ 13thȱ ISARC,ȱ pp.ȱ 895Ȭ904,ȱ Juneȱ 11Ȭ13,ȱ Tokyo,ȱ Japan.ȱ Seward,ȱ D.,ȱ 1999.ȱ Theȱ developmentȱ ofȱ intelligentȱ mobileȱ robots,ȱAȱPhDȱThesis,ȱLancasterȱUniversity.ȱȱ Seward,ȱD.ȱ W.ȱ andȱ Zied,ȱ K.,ȱ2001.ȱ Theȱ useȱ ofȱ simulationȱ resultsȱ inȱ theȱ economicȱ analysisȱ ofȱ robotizedȱ constructionȱ tasks.ȱ Proceedingsȱ ofȱ theȱ 18thȱ ISARC,ȱ Internationalȱ Symposiumȱ forȱ automationȱ andȱ roboticsȱinȱconstruction,ȱ12Ȭ15ȱSept.ȱPolandȱ Seward,ȱ D.ȱ Quayle,ȱ S.ȱ Zied,ȱ K.ȱ andȱ Pace,ȱ C,ȱ 2002.ȱ Dataȱ interpretationȱfromȱLeuzeȱRotoScanȱsensorȱforȱrobotȱ localisationȱ andȱ environmentȱ mapping,ȱ ISARCȱ 19,ȱ NIST,ȱGaithersberg,ȱUSA.ȱ Seward,ȱ D.ȱ andȱ Zied,ȱ K.ȱ 2004ȱ Graphicalȱ Programmingȱ andȱ theȱ Developmentȱ ofȱ Constructionȱ Robotsȱ ComputerȬAidedȱ Civilȱ andȱ Infrastructureȱ Engineeringȱ19ȱ(1),ȱ64–80.ȱ SRS,ȱ2002.ȱRoad/railȱVehicles,ȱaȱproductȱsurvey,ȱSwedishȱ RailȱSystemsȱ Stevens,ȱ R.,ȱ Brook,ȱ P.ȱ Jackson,ȱ K.ȱ andȱ Arnold,ȱ S.,ȱ 1998.ȱ Systemsȱ engineering,ȱ copingȱ withȱ complexity.ȱ PrenticeȱHallȱEurope,ȱISBN,ȱ0Ȭ13Ȭ095085Ȭ8,ȱLondon.ȱ Taylor,ȱ C.ȱ J.,ȱ Chotai,ȱ A.ȱ andȱ Young,ȱ P.ȱ C.,ȱ 1998.ȱ ProportionalȬintegralȬplusȱ (PIP)ȱ controlȱ ofȱ timeȱ delayȱsystems,ȱProc.ȱInstnȱMechȱEngrsȱVȱ212ȱpartȱI.ȱ Taylor,ȱ C.ȱ J.,ȱ Chotai,ȱ A.,ȱ andȱ Young,ȱ P.ȱ C,ȱ 2000.ȱ Stateȱ spaceȱ controlȱ systemȱ designȱ basedȱ onȱ nonȬminimalȱ stateȬvariableȱ feedback:ȱ Furtherȱ Generalizationȱ andȱ unificationȱ results,ȱ Internationalȱ Journalȱ ofȱ Control,ȱ V73ȱpp.ȱ1329Ȭ1345.ȱ Thomas,ȱ A.,ȱ Pearce,ȱ C.,ȱ Curry,ȱ N.ȱ andȱ Reihlȱ ,J.,ȱ 2002.ȱ Needsȱ analysisȱ forȱ avoidanceȱ ofȱ hazardsȱ inȱ constructionȱ byȱ meansȱ ofȱ automation,ȱ Northȱ Westȱ DevelopmentȱAgencyȱReport,ȱUK.ȱ UC3000,ȱ 2000.ȱ Factoryȱ Automationȱ Catalogue,ȱ Pepperl+Fuchs,ȱwww.gb-pepperl-fuchs.comȱ Wing,ȱR.ȱD.,ȱ1989.ȱRoboticsȱinȱconstructionȱ–aȱstateȱofȱtheȱ artȱ review,ȱ Proceedingsȱ ofȱ theȱ Institutionȱ ofȱ Civilȱ Engineering,ȱPartȱ1,ȱpp.ȱ937Ȭ952.ȱ Young,ȱ P.C.,ȱ 1985.ȱ Theȱ Instrumentalȱ Variableȱ Method:ȱ aȱ practicalȱ approachȱ toȱ identificationȱ andȱ systemȱ parameterȱ Estimation.ȱ Identificationȱ andȱ Systemȱ ParameterȱEstimation,ȱppȱ1Ȭ15.ȱ Young,ȱ P.C.,ȱ 1996.ȱ Aȱ generalȱ approachȱ toȱ identification,ȱ estimationȱ andȱ controlȱ forȱ aȱ classȱ ofȱ nonlinearȱ dynamicȱ syatems.ȱ Inȱ M.ȱ I.ȱ Friswellȱ andȱ J.ȱ E.ȱ Motherheadȱ(Eds),ȱIdentificationȱinȱEngineeringȱandȱ Systemsȱ(SwanseaȱUniversityȱofȱWales),ȱpp.ȱ436Ȭ445.ȱ

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Young,ȱ P.,ȱ Chotai,ȱ A.,ȱ McKenna,ȱ P.ȱ andȱ Tych,ȱ W.,ȱ 1998.ȱ ProportionalȬintegralȬplusȱ (PIP)ȱ designȱ forȱ deltaȱ ( G )ȱ operatorȱ systemsȱ Partȱ 1,ȱ SISO,ȱ Internationalȱ JournalȱforȱControl,ȱVȱ70ȱNo.ȱ1ȱpp.ȱ123Ȭ147..ȱ Young,ȱ P.ȱ C.,ȱ Taylor,ȱ C.ȱ J.,ȱ Pedregal,ȱ D.ȱ J.,ȱ Tych,ȱ W.ȱ andȱ McKenna,ȱ P.ȱ G.,ȱ 2003.ȱ Systemsȱ identification,ȱ timeȱ seriesȱanalysisȱandȱforecasting,ȱtheȱCaptainȱtoolbox,ȱ Centreȱ forȱ Researchȱ onȱ Environmentalȱ Systemsȱ andȱ Lancasterȱ University.ȱ Statistics,ȱ (www.es.lancs.ac.uk/cers/captain).ȱ Zied,ȱK.,ȱSeward,ȱD.,ȱDolman,ȱA.ȱandȱReihl,ȱJ.,ȱ2000.ȱTheȱ developmentȱ ofȱ aȱ roboticȱ systemȱ forȱ toolȱ deploymentȱ inȱ hazardousȱ environment,ȱ ISARCȱ 17,ȱ Taipei,ȱTaiwan,ȱpp.ȱ179Ȭ184.ȱ Zied, K. and Seward, D., 2003, “Towardsȱ aȱ Comprehensiveȱ Feasibilityȱ Analysisȱ forȱ theȱ Useȱ ofȱ Robotsȱ inȱ theȱ Constructionȱ Industry”, 20thȱ ISARC,ȱ Sept.ȱ2003,ȱEindhovenȱ,ȱHolland.ȱȱ Zied,ȱK,ȱ2004.ȱInvestigationȱofȱtoolsȱandȱprocessesȱforȱtheȱ rapidȱ developmentȱ ofȱ intelligentȱ robticȱ systemsȱ forȱ hazardousȱ environments,ȱ Aȱ PhDȱ Thesis,ȱ Lancasterȱ Universityȱ

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