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Page 1 of 8 Project title / Job position title: Ph.D. Fellowship in Efficient Flank Computer Numerically Controlled (CNC) Machining with Generally-Curved Milling Tools Research Project / Research Group Description. Geometric modelling of free-form surfaces represented by non-uniform rational B- splines (NURBS) is straightforward using a proper CAD software. The real challenge, however, appears when the highly curved object is to be manufactured. Flank (or peripheral) computer numerically controlled (CNC) milling is the final stage of the machining process where the milling tool touches tangentially the material block. Traditionally, the milling tools are cylinders and cones. However, using predefined tools is highly inefficient, as they do not consider the input geometry. Recent research has shown promising results towards flank milling with curvature varying tools [2]. The aim of this project is to incorporate the optimal geometry of the milling tool into the whole manufacturing process. This involves accessibility and movability analysis, motion planning, and shape and motion optimization. Mathematical understanding of the given free-form shape is essential for efficient manufacturing process. For a given input surface, there exist regions of the surface that admit good approximation using the milling tool and regions that are totally unaccessible [2]. Optimal slope and size of a conical tool and its trajectory has been studied recently [1]. We aim to go further this direction and, for a given input geometry, design a set of tools together with their motions in 3D to perfectly approximate the designed shape. Ph.D Advisor: Michael Barton, PhD (Computational and Applied Mathematics, Charles University, Prague, 2007) [email protected], http://www.bcamath.org/en/people/mbarton The proposed project is composed of two parts. a) The Ph.D. student will study the accessibility analysis between a generally- curved NURBS surface (reference model) and surface of revolution (milling tool) and will implement algorithms to navigate the predefined tool tangentially along the reference model. b) The Ph.D. student will design algorithms that will seek the set of tools and their 3D motions to approximate the reference geometry with maximum coverage. Keywords: 5-axis CNC machining, Custom-shaped milling tools, Flank milling References: [1] Bo, P., Barton, M., and Pottmann, H. Automatic fitting of conical envelopes to free-form surfaces for flank CNC machining. Computer-Aided Design, 91, pp. 84-94, 2017. [2] Bo, P., Barton, M., Plakhotnik, D., and Pottmann, H. Towards efficient 5-axis flank CNC machining of free-form surfaces via fitting envelopes of surfaces of revolution.

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Page 1: Project title / Job position title: Ph.D. Fellowship in ... · Project title / Job position title: Ph.D. Fellowship in Efficient Flank Computer Numerically Controlled (CNC) Machining

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Projecttitle/Jobpositiontitle:Ph.D.FellowshipinEfficientFlankComputerNumericallyControlled(CNC)MachiningwithGenerally-CurvedMillingToolsResearchProject/ResearchGroupDescription.Geometricmodellingoffree-formsurfacesrepresentedbynon-uniformrationalB-splines(NURBS)isstraightforwardusingaproperCADsoftware.Therealchallenge,however, appearswhen thehighly curvedobject is tobemanufactured.Flank (orperipheral)computernumericallycontrolled(CNC)millingisthefinalstageofthemachiningprocesswhere themilling tool touches tangentially thematerial block.Traditionally,themillingtoolsarecylindersandcones.However,usingpredefinedtools is highly inefficient, as they do not consider the input geometry. Recentresearchhasshownpromisingresultstowardsflankmillingwithcurvaturevaryingtools [2]. The aim of this project is to incorporate the optimal geometry of themilling tool into thewholemanufacturingprocess. This involves accessibility andmovabilityanalysis,motionplanning,andshapeandmotionoptimization.Mathematical understandingof the given free-formshape is essential for efficientmanufacturingprocess.Foragiveninputsurface,thereexistregionsofthesurfacethat admit good approximationusing themilling tool and regions that are totallyunaccessible[2].Optimalslopeandsizeofaconicaltoolanditstrajectoryhasbeenstudied recently [1]. We aim to go further this direction and, for a given inputgeometry, design a set of tools together with their motions in 3D to perfectlyapproximatethedesignedshape.Ph.D Advisor: Michael Barton, PhD (Computational and Applied Mathematics,Charles University, Prague, 2007) [email protected],http://www.bcamath.org/en/people/mbartonTheproposedprojectiscomposedoftwoparts.

a) ThePh.D. studentwill study theaccessibilityanalysisbetweenagenerally-curvedNURBSsurface(referencemodel)andsurfaceofrevolution(millingtool) and will implement algorithms to navigate the predefined tooltangentiallyalongthereferencemodel.

b) ThePh.D. studentwilldesignalgorithms thatwill seek the setof tools andtheir 3D motions to approximate the reference geometry with maximumcoverage.

Keywords:5-axisCNCmachining,Custom-shapedmillingtools,FlankmillingReferences:[1] Bo, P., Barton, M., and Pottmann, H. Automatic fitting of conical envelopes tofree-formsurfaces for flankCNCmachining.Computer-AidedDesign,91,pp.84-94,2017.[2]Bo,P.,Barton,M.,Plakhotnik,D.,andPottmann,H.Towardsefficient5-axisflankCNCmachiningoffree-formsurfacesviafittingenvelopesofsurfacesofrevolution.

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Computer-AidedDesign,79,pp.1-11,2016.[3]Harik,R.F.,Gong,H.andBernard,A.5-axisflankmilling:Astate-ofthe-artreview.Computer-AidedDesign,45(3),pp.796–808,2013.

JobPositiondescription.ThePh.D.studentwilldevelopalgorithmsforflankCNCmachining.Requirements:

- Masterdegree(preferable inAppliedMathematics,EngineeringorComputerScience). The candidatemust have his/herMasterDegree completed beforetheincorporation.

- Applicantsmusthavedemonstratedexcellentcapabilitiesinseveralresearch-orientedprojects.

Skills:

- Goodcommunicationandinterpersonalskills.- Ability toeffectivelycommunicateandpresentresearch ideas toresearchers

withdifferentbackground(e.g.,mathematiciansandengineers).- Abilitytoclearlypresentandpublishresearchoutcomesinspoken(talks)and

written(papers)form.- GoodlevelofspokenandwrittenEnglish.

GroupLeader:➢ FullName:MichaelBarton➢ Email:[email protected]

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INPhINITOffer:INPhINIT targets the most motivated PhD candidates by addressing the researchareas in which Spain excels: Bio and Health Sciences, Technology, Physics,Engineering and Mathematics.INPhINIT recruits per call 57 Early-StageResearchersofanynationality,whoenjoya3-yearemploymentcontractattheResearchCentreoftheirchoiceamongthoseselectedandawardedbytheSpanishMinistryofEconomyandCompetitiveness("SeveroOchoa"centresofexcellenceand"MariadeMaeztu"unitsofexcellence)andtheSpanishMinistryofHealth("CarlosIIIcentres of excellence"). In addition, researchers establish a personal careerdevelopment plan including trasnational, intersectoral and interdisciplinarymobility opportunities, and attend a full range of complementary trainingcoursesandworkshops."la Caixa" Foundation will select international candidates. Subsequently, theselectedcandidates,willproposetheResearchCentreandthepredoctoralpositioninwhichhe/shewouldliketodotheresearchproject.IfthereisagreementbetweentheCentre,thesupervisor(predoctoralresearcherwhopresentedtheposition)andthecandidate,thefellowshipwillbeawardedtothecandidate. Fellowshipprovisions:

- 3-yearscontract- Recruitment date: September / October 2018. January 2019 under

extraordinarycircumstances.- Fundingperfellow:115.092euros

o 104.400euros (34.800eurosperyear) includingsalary,employeesocial security contribution, income taxes and all compulsoryemployers’contributions.

o 10.692 euros (3.564 euros per year) for research costs such asconferencesandworkshopsattendance,short-stays,consumablesandintellectualpropertycosts,amongothers.

- PhDAwardof7.500euroswillbegrantedtoresearchersthatsubmittheirthesiswithin6monthsaftertheendofthefellowship.

- Complementarytrainingprogramme:o TechnologyTransferandEntrepreneurshipworkshopsbyOxentia.o ProfessionalandCareerDevelopmentsessionsbyVitae.o High‐qualityacademicandindustrialsecondments.o Participationinoutreachandsocialevents.

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HowtoApply1. Clickinhttps://hosts.lacaixafellowships.org/finder,clickinRESEARCH

CENTREandchoose“BasqueCenterforAppliedMathematics-BCAM”

2. Click in “SEARCH” and the displayable will list the positions offered

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3. Click in the selected PhD Offer and click in “START THE APPLICATION”

4. The system will open a new window with the application website https://www.lacaixafellowships.org/index.aspx. Click in “Please register” for new applicants.

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5. After the registration, the system will send to you the confirmation email and the link to access into the system. Now you are in the position to access into the application system. Please choose INPhINIT: Doctorate in Spanish Research Centre of Excellence

6. Nowyouare in theposition to fill theapplication form,upload the requireddocumentsandchoosetheprojectthesis.Tochoosetheprojectthesis,clickin“StudiestobePursued”,choosethecentreandtheposition

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Eligibilityrequirements

- Atthepublicationdateofthefinallistofselectedcandidates(29may2018),candidates must be in the first four years (full-time equivalent researchexperience) of their research careers and not yet have been awarded adoctoraldegree.

- Atthetimeofrecruitment,candidatesmustcomplywithoneofthefollowingoptions:

o TohavecompletedthestudiesthatleadtoanofficialSpanish(orfromanother country of the European Higher Education Area) universitydegreeawarding300ECTScredits, ofwhichat least60ECTScreditsmustcorrespondtomasterlevel.

o Tohavecompletedadegreeinanon-Spanishuniversitynotadaptedtothe European Higher Education Area that gives access to doctoralstudies. The verification of an equivalent level of studies to the onesmentionedabovewillbemadebytheuniversitywhentheadmissionprocedurestarts.

- Mobility Rule: Candidatesmustnothave residedor carriedout theirmainactivity(work,studies,etc.)inSpainformorethan12monthsinthe3yearsimmediately prior to the publication date of the final list of selectedcandidates(29may2018).Shortstayssuchasholidayswillnotbetakenintoaccountwhencalculatingthemobilityrequirement.

- DemonstrablelevelofEnglish(B2orhigher). EvaluationandselectionprocessINPhINIT aims to recruit excellent Early-Stage Researchers with very solidtheoreticalbackgrounds,withcuriosityandambition;withincipientskillstoexpressthemselves clearly and defend their ideas with creativity, independence andoriginality.Researchersmaybe focusedontheacademicsideorbemore industry-oriented.Theevaluationcriteriaandscoresdefinedtoachievethisgoalare:PHASE1-REMOTEEVALUATION:

- Academic record and CurriculumVitae (weight 50%): academicand/orprofessional curriculum in relation to the stage of the candidate’scareer;Motivation and statement of purpose (weight 30%): theoriginality, innovationandpotential impactof theproposedproject,andthechoiceoftheResearchCentrewillbeassessed;

- Letters of reference (weight 20%): reference letters supporting thecandidacywillbeassessed taking intoaccount the specificityof the contentwithregardtothecandidate’sprojectaswellastheprofileofthepeoplewhosignthem.

PHASE2-FACE-TO-FACESELECTION:

- Candidate’spotential(weight40%): inordertohaveageneralperceptionofthecandidate’spotential,expertswillpayattentionto“soft”skills,abilitytopresent easily a complex reasoning, teamworking; and capabilities such as

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independent reasoning, originality, entrepreneurship, leadership, amongothers.

- Motivation and statement of purpose (weight 30%): expertswill assesstheimpactoftheprojectforthecandidateandthesociety;projectinnovation,originality and feasibility; and candidate’s capabilities with regard to thescopeoftheproject.Academicbackgroundandtheoreticalfundamentals(weight 30%): experts will assess the consistency of the candidate’sacademicbackgroundandCVintheareachosentocarryoutthePhD.

Accordingtothenumberofapplicationsreceived,theremaybeapre-selectionphasebasedonthefinalacademicmarksobtainedfortheBachelorstudies.