Content › files › marine › files › ROV... · 2019-04-18 · Budget Seahawk construction was made ... To perform the tasks of the MATE 2016 competition, we needed an engine

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AbstractSeahawk was built to make the finalthesis of three students; AdanManoloFlores Celis, Rodolfo Arturo VeraHerrera and Angel Alberto HernandezGonzalesinordertoprovehiscareerasa mechanical engineer, then thenumber of team members wasextendedtoimprovetheROVtoattendinternational competition MATE 2016which5memberswereaddedmore.ThisROVwasalsobuilttodonatetotheFaculty of Engineering of the

Universidad Veracruzana in order tomaketeachingmaterialsforstudentsofthefaculty.The ROVwasmodified almost entirelywiththeprimaryaimofmeetingallthestandards that marks the MATE 2016competition.The vehicle is designed to withstandpressuresgreaterthan50metersbelowsealevel,hastwocameras,temperaturesensors,pressure,altitude.

ROVSeaHawk

BudgetSeahawk construction was madepossible by generous donations fromfacultyoftheUniversidadVeracruzana,bothmechanical engineering career asother races. Around a quarter ofrevenuesbelongtodonations, therestwere own resources students throughraffles and parental support wasachievedcollectthefullbackground.

The initial budget was $ 740 wasconceived early last year with theconstructionbegan.Regarding the budget for 6 personsrespect to travel, accommodation andlogistics was achieved thanks todonations from private companies inthe community. It had contemplatedtraveling8studentsparticipatingintheproject, which was difficult to get somanyresourcessoonlytravelinJune.

Description Unit Costdls total

ThrusterT100 4 149 596

Temperaturesensor 1 56 56

Pressuresensor 1 68 68

Cablepenetrator 20 8 160

Aluminumendcap 2 26 52

CamGoproHD 2 280 560

Send 1 200 200

Hydraulictubecodo90 12 1 12

HydraulictubeTEE 11 1.5 16.5

Hydraulictubecross 5 1.5 7.5

PipePVC25mm 1 5 5

PipePVC19mm 1 3.5 3.5

Screws 50 0.1 5

Nuts 50 0.1 5

LoctiteMarineEpoxy 2 6 12

PottingKit 1 1 1

Nylonrope 1 10 10

Suctionpump 1 83 83

Checkvalve 1 22 22

Endlessclamps 2 1 2

UTPcable 1 27 27

Powercable 1 32 32

Waterproofservo 1 60 60

BasicA30ESC 4 25 100

Joystick 2 2.5 5

Cabledupont 2 5 10

Monitors 3 75 225

LCDscreen 1 20 20

Watertigthenclosure4" 1 56 56

Battery 1 160 160

Lamp 2 99 198

Accelerometer 1 100 100

IMU 1 40 40

TotalDls 2909.5

TotalPesos 52371budgettable

DesignbasicsThe design was decided after seeingmanyprototypesontheInternet,Iwasheld to sketch taking ideas fromother

prototypestochoosetheoptimum.Then we proceeded to implementtechnological aids today such as CAD(Computer Aided Design), where theSolidWorkssoftwarewasusedtomakeanoptimaldesignandsubsequently tocarryouttheconstructionaccordingtoplan.

ItsstructureisPVCplasticthatisusedinhydraulic systems, joints of the samematerial. It was decided to make arectangularshapewhichchoseitforitseasy construction and shape whichhelpsustohavebetterstabilityinwater.Its dimensions are 56 cm long, 35.52wideand34.5cmhigh.

DesingSolidWorks

DesingSolidWorks

Hardware The hardware is a vital part of thesystem, we use an Arduino board onwhichisthemotherboardofoursystembecauseitisabletocontrolit.

a waterproof case for electronicelements Iwasused,whichconsistsofanacrylictube4inchesindiameterand½inchthick.elements of stainless steel hardwarewasalsousedaseverythingisexposedtocorrosion.

Propellers

ToperformthetasksoftheMATE2016competition,weneededanenginewithenoughforcethatfavoredus.brushlessmotorsbought thebrandBlueRoboticsmodel T100, which were purchased inCalifornia,U.S4motorswereusedandpositionedasfollows:

• 2motors(up/down)• 2motors(front/rear)

T100BlueRobotics

The T100 propellants are nearlysymmetrical on the directional thrustoutput lbf to 5.2 lbf forward and fourrever

ManipulatorThemanipulator is able tomanipulateobjects under water less than 2 kg.weight,hasonlyonedegreeoffreedom,asthis inafixedpositionandthefrontsideofROV.Itisofaluminummaterialanodizedandis driven by a servomotor 17 kg. oftorquebrandHi-tec,whichallowsustoopenandclosethegripper.

Iwaspaintedred,aswhenperformingthe tests, we presented the problemthatthecolorwaslost.

Gripper

SpeedControllersControllers for brushless motors T100areofacapacityofupto30amps,whichenables us to control the motorsthroughPWMdigitalsignalsaswellasto

controlthedirectionoftheenginesandmeetsourneedformovement.The drivers were bought online andimportedtoourcountry.

Motorcontroller

CommunicationThecommunicationsystem in theROVis designed for a tether up to 45 m,which introduces a number ofchallenges. 4motors to control and totransmit two cameras, a lot ofbandwidthinourattachmentisneeded.Wehadagreatdifficultywhichstoppedus for quite some time, you had avoltage dropwhich only allowed us towork about 5 to 10 minutes ROVunderwater, which delayed us greatly,and we thought it was problemprogramming and a lot ofwork in thecodewhichwasnotthesolution,afteritwas cable replacement and a smallercaliber, finally the caliber usedwas 10AWGasweused18AWGwire.Our communication consists of 3elements, two power cables (positiveand negative) and an Ethernet cable 8wires by which the ROV control isperformed.In conjunction with this, a polyestercordwasplacedtogivestrengthtothestrap, so that the burden was on the

ropeandnotthewires.Togethertheseelements form the rope attachedcommunication.

Communicationcord

InterconnectionSystemDiagram(SID)OurcompanyROVs,youdecidedtocallHalcones UV, was created with theintention of working in harshenvironments, aswell as othermarinehabitats. TheaimofHalconesUV is todesign,developandtestanROVabletosolvedifferentmissionsandtaskssuchas navigation, vision and interactionwith hostile environments underseawater.Toachievethis,theROVwas

designedandimplementedinawaythatpossible work in these situationswithout exceeding budget previouslyset.Thehardwareisdistributedinthreedifferent areas: the system of surfaceattachment and ROV systemunderwater.

DiagramSID

WaterproofcaseDry to keep all electronic devices iscrucial for a good performance of anyproduct that is intended to use inwetenvironments.Therefore,theelectroniccontrolboxwascompletelyisolated. After much research, the firstthingwedecidedtomakeourowncase.TheinitialdesignwasanacrylictubeinwhichassembleelectronicsROV.Butwehad a serious problem because it wasnot completely airtight, so finallydecided on a tubemade by ... ..Most

electronicboardsandcomponentsusedare rectangular or square in shape,whichmadeiteasytoaccommodateallthecase.

We have also had to adaptseveralconnectorstightlywiththecaseofEthernetandpowercablesandwiresof motors and various sensors. Toensure double protection, each has itsownconnectorO-ringontheinsideofthebox.

Acrylicwaterpoofcase

EthernetcommunicationCommunication between the ROV andthe controller (which is conducted themain data processing) is performedthrough an Ethernet crossover cable45mm long tipo6 approximate.One ofthe main reasons for Ethernet waschosen over other means oftransmission(includingstandard)isthegreat distance that covers thetransmission of data as ROV need totravelandexplorearound12-30meterslongandabout15metersunderwater.Resultinginanapproximatetotalcabledistanceof40meters.

Anotheradvantageofthetransmission over Ethernet is

data integrity, since it has highreliabilityanddata lossareataminimum rate. To reduce thisloss we are using an STP(shielded twisted pair), whichincreases protection againstelectromagnetic interference(justincasetherewouldbeno).

Ethernet also provides

theabilitytotransmithighspeedand high transmission capacity(up to 10 Gb and 500 MHz1)reducing latency and ensuringthe data frame arrive on timeand with all the information isreliableandcomplete.

SoftwareTo operate the Seahawk we havecreatedaprocessingprogramwhichisaprogramming language based on opensourceJAVA(Processing).Amongotherprogramming languages andenvironmentswechosebecause ithassomeadvantagesProcessingofinteresttousthanotherlanguages.

Processingisafriendlylanguage.While other programmingenvironments seem complex andrequire the user to have a greatexperienceincodingandinterpretationof the code instructions and theirresults,productionissimple,butnolesspowerful. Reference is always at handfans giving programmers a simplestructure and skilled ones, a familiarformbutlesscomplexthanwhatthey'reusedtodoing.Itisalsoanenvironmentobject-oriented programming, whichallows us to test and observe throughdifferent angleswhatwe are trying toachievewitheachcommand.

Processingalsohaslibrariesthathas Ethernet communication, withinstructionsinturn,theyarealsosimple.It also has a processing fee, so alloperationsrequiredforourprogramintime for transmission so that theperformance of our ROV see notaffected by latency or any other issuerelated to the processing andtransmission.

Another reason to choose thislanguage was its compatibility withArduino. As discussed later in thisreport,ArduinowasusedtocontrolthefunctionsofSeahawk internally, so thelanguage that was used, it wasnecessary to connect it to an Arduinoprogram first. Most of the otherlanguages need an intermediary tomake the connection and theprocedures were complicated intransmission time, so our ROVperformancewould suffer. In the end,production was the best option, sincethe connection with Arduino wascarried out almost automaticallyretainedanddataintegrity.

ControlOurROVusesfourenginestogenerateallthenecessarymovementsalsohavecomponents such as sensors and gripthey need a simple control system forthispurposeusingjoystick,buttonsandvariableresistorsimplemented.

We use two interfaces to themovements of the ROV, the first ismanualinterfacethatisactivatedatthebeginning of the program, the speedrangeoftheengineiscontrolledbythejoystick, which have speeds of 1100-1900microsecond,being1500lasteady

speed, speeds of 1,100 to 1,500 arereverse speeds and speeds between1500to1900areforwardspeeds.

Now, in the first interface, weusetheleftsticktomovetheROValongtheaxisXandY,andcanalsomovetheROV at different angles and speeds,accordingtotheangleandmovementoftheleftlever.

TheXaxisoftherightjoystickisused for rotational movements of theROV,inthisinterface,wecanonlymoveastickwhenthatplaneXYmovements.The Y axis of the lever on the right is

used to tiltmovements. In the secondinterface,weusetheleftsticktomovetheROVontheYaxisandtherightstickisusedforrotationandimmersion.

TheROV is operatedby apilot,leads the ROV with the joystickcontroller, our control has somecharacteristics from the fact that eachline of code and logic behind themovementoftheROV.Inaddition,thecode was designed to allow the

Seahawk movement in every possibleway. This was not achieved the coughbutincertaincases.Although our laptop and processingitself have a great ability to "process"that did not want to do unnecessaryoperations or overburden operationsArduino, so we added a feature thateliminates data and prevents it frombeingsentoverthewireEthernet.Thesedataaretoavoidastrangemovementinthethruster.

Flowchart

Electronics

The whole system is controlled by anArduinoMegaADK,wedecided tousethisboardmainlyduetoits15-pinPWMandthefactthatweneedaround13-pinPWM for our engines and ourequipment.Atfirstwewerethinkingofusingacardarduinoone,butdoesnothavealotofthistypeofpins.

Wehavealsodecidedtousethiscard as it is easy to program and hasmore components and sensors thanothers.PressuresensorROVs position is important for pilots,therefore, we chose MS5803--14BA apressure sensor to calculate thedepthposition ROVs. This pressure sensormeasures theabsolutepressureof thefluidaroundit,includingair,water,andanythingelsethatactsasaviscousfluid.

What makes the uniqueMS5803--14BA is gel membrane andantimagnetic stainless steel cap whichprotects against water pressure of 30bar. It is connected to the ArduinoMega, and the data is shown incentimetersforgreateraccuracy.AccelerometerThe ADXL335 is a three-axisaccelerometerwithvery lownoiseandpower consumption. The sensor has arangeofcompletedetectionof+/-3g.We use this sensor to measure thedistance between the camera and theobjectofourimageprocessingsystem.

Temperature and humiditysensorThis sensor includes a resistive -moisturemeasurementcomponentandacomponenttypeofNTCtemperaturemeasurement.Itisconnectedtoahigh-performance 8 - bit microcontroller,which offers excellent quality, fastresponse,anti-interferenceabilityandcost-effectiveness.Forsafetyreasons,thissensorisusedtodetermine if there is a water leakthrough our electronic box or if oursystemisoverheating.BombTocarryoutoneoftheteststhatweredetermined to complete for the test isthe fact suctioning liquid forstudiesofthe same, and determine itscompositionwasdecidedtoputatypepump ... also adding a check valve topreventabackflowoftostudythisliquidismountedwithinthestructureofROVsecurely fastened to prevent theSeahawkhavemalfunction.

MechanicalSafetyChecklist

1. Ensure that all electronicequipmentisindryandthereisno perceptible damage theunion.

2. Checkthefuseintheconnector

25Asupply12V.

3. ROVoutofthewater,checkthatall connectors are tight andvacuumsealsareinallcases.

4. Checktheo-rings.

5. Safety equipment and personal

protectiveteammembers.

6. Check that all equipment mustbesure:Screws,brackets,ballastsuctionpumpcheckvalve.

7. Ensure that the connection

cablesinthewaterproofcaseareproperlyconnected.

8. The umbilical cord must be

properly stretched and shouldnotbetwisted.

9. Verifythatthevideocameraisinthecorrectposition,keepsignaland can give image on thescreens.

10. Ensure that all penetrators are

closed before putting the ROVintothewater.

11. Verify that the power cable is

securely connected to thebattery.

12. Verifythatthearmworkbeforesurgery and gears are securelyinstalledinplace.

13. OverallRatingROVbytwoteam

members.

14. Besuretofollowtheguidelinesandinstructionsofcompetition.

ReflectionsAswithallprojects,thereareplentyofexperiences in which to reflect. Theteam started with three students andthen there are eight. Fortunately withthe increase in the number of teammembers, we can become morespecialized in various fields, whichallowsus tounderstandthespecialtiesin more detail. By having studentsstudying mechanical, electrical andmechatronicsIhelpeduslearnhowlittleormucheachofuscancontribute.

Sometimesitisdifficulttomakea decision when there are too manypoints of view and differentexperiences, but teamwork is a virtuallarge and vital to achieve the samepurpose, there are different culturesand ways of thinking that it is oftendifficulttoonemind.

Theexperienceofbeingable totravel andparticipate in a competitionof international stature is anunforgettable experience, to meetpeople from around the world wereprepared similarly to give the bestresultsinthecompetition.

Thanks:

I thank the University Veracruzana our highest seat of learning for its support inprovidingworkareasinwhichweworkedtogivelifetothisgreatprojectsupport.

Grateful to our professors;M.I. Alvaro Gabriel Vega De La Garza,M.I. Azzur

Mariano Hernandez Contreras, Dr. Rogelio De Jesus Portillo Velez, M.I. FranciscoMartinezOrtiz,Dr.AdrianSantoVidal,Ing.JulioCesarAmezcuaAlcázar,M.I.JoseJuanFragosoMontalvo,M.I.ArmandoCamposDominguez,M.I.EstelaDelCarmenFernandezandEng.JoshuaDominguezMarquezforallthesupportprovidedbyitshumanqualityand itseconomicand intellectual support instruct andguideus tomake thisprojecttodayisalreadyafactsupport,keepusconfidenceatalltimes.

MATE also thanks to the opportunity they give us to allow ourselves toparticipateinthisgreateventwherewecanapplyknowledgegainedintheracefortheconfidencethathasonstudentstocarryoutthesetypesofprojects.

AcompanyTng"TalleresNavalesdelGolfo"institutionthatgaveusthefinancial

supportweneededbecausewithoutitwouldnothavesucceededthisproject.

Athankyouallarepartofthis.