a study into the application of the arduino mirco-computer for use as a navigation system

8/12/2019 A Study Into the Application of the Arduino Mirco-Computer for Use as a Navigation System.

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OConnor, Ryan Maritime Robotics Project: Small Autonomous Marine Vehicle

A Study into the Application o the Arduino Mirco!Computer or use as a"a#i$ation System%

Author: Ryan OConnorSupervisor: Shinsuke Matsubara

Australian Maritime College, NCMEH

Abstract

A low cost navigation system was designed and adapted to a catamaran hull which was provided by

the Australian Maritime College. The Arduino Mega micro-controller was used in conunction with the

Ardu!M" #$ to control the direction o% the vessel, and create a %ully autonomous system. The system was

then tested at the Australian Maritime Colleges Model Test &asin, with the use o% the 'ualysis stop motion

cameras to attain the position and heading data. This (ata was then processed through the use o% Mat)ab

and E*cel to determine the accuracy o% the navigation program and the various onboard sensors. The

navigational control program o% the vessel was shown to have a considerable error and struggled tocomplete the pre-programed path. The Ardu!M" #$, which was used to determine the vessels bearing,

accelerations and rotations, was shown to have very little error in determining the vessels heading with

relation to magnetic north. Along with the !M", an ultrasonic sensor was included into the system. The

ultrasonic sensor allowed the vessel to become a %ully autonomous vessel that was capable o% ma+ingdecisions based on the surrounding environment.

Keywords:A"#, Autonomous, #essel, Arduino, !M", !N, low cost, Ardu!M" #$, Navigation

& 'ntroductionThe need for Autonomous vehicles in the maritime industry is said to increase over the next decade

ith over !""" A#$s bein% procured &Marport' ("!")* Creatin% a +o cost A#$ ill enable the use ofmultiple A#$s from one platform' increasin% the amount of oceano%raphic,%eolo%ical data bein%collected*

This paper details the desi%n process involved in creatin% a lo-cost navi%ation system to provideautonomous control to various types of vehicles* This particular system as adapted to a small boat andtested at the Australian Maritime Colle%es Model Test .asin* The Arduino Me%a micro-computer asused in con/unction ith the Ardu0M# v1 to control the path of the vessel*

&%& Scope

The aim of this pro/ect as to create an autonomous vessel that as capable of makin% decisions basedon the environment that it is operatin% in* This pro/ect involved researchin% and developin% a lo costnavi%ation system for an autonomous vessel*

The Arduino Me%a alon% ith the Ardu0M# $1 as the chosen micro-computer used in this system*This microcomputer as pro%ramed to move alon% a number of set courses ith its ability complete thiscourse determinin% the accuracy of the system*

Once the model as built and pro%rammed it as be tested to determine the overall accuracy of thevessels ability to maintain its headin%' course' and its accuracy at reachin% its final marker* The pro/ectill utilise the facilities provided by the Australian Maritime Colle%e' ith the testin% of the model in themodel test basin &MT.)* The accuracy of the model ill be determined by analysin% the data from theMT.s stop motion video cameras*

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Once the testin% as complete' the data received from the 2ualisys cameras and the Ardu0M# $1 asthen analysed to determine the accuracy of both the pro%ram and the Ardu0M# $1 sensor*

( )iterature Re#ie*A literature survey as conducted to determine an application for the Arduino micro-computer* This

initial survey as done' a navi%ation application for the Arduino as chosen* A further survey into this

particular area as undertaken* A lot of this literature as found primarily from the Ocean 3n%ineerin%4ournal' ith other sources bein% various internet /ournals' ebsites and the #niversity of Tasmanias+ibrary*

(%& Re#ie* o Papers

5revious ork has been taken into the development of an Arduino poered autonomous underatervehicle &A#$)* 6ithin this paper the author' .us7uets &("!()' states that by loerin% the cost of A#$sill introduce the ability to operate multiple A#$s from a sin%le parent vessel* 4alvin% &(""1) explainsthat there is a lar%e amount of cost and effort that %oes into the development of navi%ation systems andinertial measurement units' he also provides reasonin% behind the use of a 8alman filter to eliminateexcessive noise ithin the pre-processed data*

.ahr &(""9) discusses that there are inconsistencies ith 5S resultin% in the need for a navi%ationsystem hich operates underater* ;e also details ho a basic 0


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/i$ure +!&: the AMCs model test basin /i$ure +!(: 0 .ualisys motion Capture cameras on the

let side o the basin%

+%( 1estin$ matri-

Testin% as conducted to determine the vessels ability to traverse a pre-pro%rammed course* Tocourses ere used durin% testin% a path ith a sin%le !?" de%ree turn and a path ith to 9" de%ree turns*The sin%le turn test involved the vessel travellin% forard for a set amount of time before preformin% asin%le !?" de%ree turn* A similar method as used for the second test' here the vessel ould travel for aset time and then make a 9" de%ree turn' it ould then travel for another set amount of time before makin%its second turn* The full list of tests alon% ith their full descriptions is shon in Table !*

1able &: 1estin$ Matri-

1est

1ype

"umber o

Runs 2escription

.ualysis

recordin$

345"6

S2 card

recordin$

345"6

Sin%le

turn !"

The vessel moved forard and then preformeda !?" de%ree turn returnin% the vessel to its

ori%in B


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= 2esi$n and 2e#elopmentAs the Micro-Computer as chosen to be the Arduino Me%a' all components ere chosen to be

compatible ith this board* There ere to aspects to this desi%n' these ere the system desi%n hichincorporated the development of the F kb memory &Arduino' ("!1)* The Me%a re7uires a >volt poer supply to poer the board and all its peripherals* The Me%a allos for an array ofsensors,motors to be attached and controlled accordin% the users pro%ram*

/i$ure =!>: Arduino System 2ia$ram

The Ardu0M# $1 &shon in =i%ure > -?) includes a ATMe%a 1(F processin% chip alon% ith a M5#-F""" &hich includes a 1 axis accelerometer and a 1 axis %yro' capable of calculated the roll' pitch andya of the device) and the 1 axis ;MC->??1+ ma%netometer &Sparkfun' ("!1) hich is used fordeterminin% the compass bearin%*

/i$ure =!?: Arduino Me$a board 3Arduino, (9&+6 /i$ure =!@: Ardu'M< V+ 3Spar8un, (9&+6

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The boat as poered by a sin%le motor hich as connected into the circuit throu%h an electronicspeed controller &3SC) as shon in circuit dia%ram in =i%ure > -F* The motors chosen ere a hi%hpoered ??" k$ brushless motor' developed for use ith the Arduino 7uad-copters* @C brushless motorsere chosen as they do not create any sparks durin% the mechanical operation of the motor &.rian' ("!1)*They ill also decrease the complexity of the Arduino systems by eliminatin% the need of an Arduinomotor shield* The Me%a as attached to a servo motor connected to a rudder' the me%a then used the

compass data from the Ardu0M# to determine the vessels headin%*As a precaution an ultrasonic sensor as fixed to the front of the vessel' a simple line of code as

ritten into the pro%ram to prevent the vessel from collidin% ith any sensitive e7uipment in the modeltest basin' should the vessel move of its uploaded course* The sensitivity of the sensor as set to "*!> m'should the vessel be ithin that ran%e the motor ould shut don and the servo ould turn the vesselhard-a-port* The use of an ultrasonic senor alloed for the vessel to become fully autonomous*

The system used an S@ breakout board* This board recorded the acceleration' ya and compass datathat as bein% read from the Ardu0M# $1* The data as saved as a *txt file for post-processin% usin%Mat+ab and excel* Only ten runs ere conducted ith the S@ breakout board connected to the Arduino*=or these tests the Arduino as pro%rammed to complete a !?" de%ree turn*

The Arduino Me%a ill act as the central processor in the system as shon in =i%ure > -F' ith thedata from the 0M# bein% used to control the servo motor* The system dia%ram shon in =i%ure > -F is of

the system that as developed throu%h testin%*The Arduino and its various components re7uire poer to ork* The Arduino is best suited to a > $

poer supply hile the 3SC and motor re7uired a poer supply ith a hi%her volta%e* A > $ battery bankused to rechar%e mobile phones as chosen to poer the Arduino hich subse7uently poered theArdu0M# $1' servo motor' S@ breakout-board' and ultrasonic sensor* The 3SC on the other hand re7uiredat least F-!( $ to supply poer to the motor' the hi%her the volta%e the faster the motor ill turn* A !( $battery ould have been too bi% and ei%ht too much' therefore a F $ sealed-lead acid battery as chosenfor sie' ei%ht' and poer re7uirements*

=%( Vessel 2esi$n

The Catamaran hull shon in =i%ure > -9as supplied by the AMC for use on this pro/ect* This hullprovided a stable platform for the Arduino Me%a and all components* As these hulls ere the AMCs

property' it as stipulated that no irreversible modification could be made to them' therefore anythin% thatre7uired bein% fixed to the hulls as done so throu%h any existin% scre holes*

As this system as operatin% in an environment here the electrical system as exposed to ater' thesystem as placed in a container to prevent any ater from interferin% ith the Arduino system' inaddition to protectin% the system the container also provided a platform to mount the 2ualisys motionballs* @urin% testin%' a substantial amount of ater as bein% carried throu%h the prop shaft and into thecontainer* This re7uired the shaft to be covered hile operatin%' this as done by fabricatin% a smallshield on the day*

@urin% construction consideration as taken into the position of the components* 6herever possiblethe components ere arran%ed to provide a lateral and horiontal symmetrical ei%ht distribution* Theposition of the components as hoever limited by the len%th of the ires and the position of the motorand 3SC* As the motor as fixed in the forard section of the vessel alon% the centerline this re7uired the

sealed-lead battery to be positioned further forard* Additional ei%hts ere re7uired on the day oftestin% to prevent the vessel from trimmin% by the bo* The vessel tested is shon in =i%ure > -!"*

The ori%inal system desi%n involved havin% a set value for the 3SC hich kept the speed of the vesselconstant* @urin% testin% this as impractical as calibratin% the 3SC as time consumin%' this methodould have drastically reduced the amount of tests* The problem as remedied by the addition of apotentiometer' hich alloed for the speed of the motor to be altered ithout uploadin% a different codefor each test*

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/i$ure =!: Catamaran hull pro#ided by the AMC

/i$ure =!&9: Autonomous Vessel

.efore each test the Arduino re7uired a start-up procedure* This as re7uired to reset and recalibratethe Ardu0M# and reset the timer on the Arduino* .efore each test the reset button on the both the me%aand Ardu0M# ere pushed and the model as held still in the ater to prevent a buildup of drift from theprevious test* Once the Ardu0M# as recalibrated the motor as set to the desired R5M and the vesselas left to run*

> Results@ue to time constraints only to testin% paths ere tested one as a simple !?" de%ree turn and the

other involved the vessel makin% to 9" de%ree turns* @ata as attained throu%h the use of the model testbasins 2ualisys motion capture system and by readin% the data bein% produced by the Ardu0M# $1*

>%& &@9 de$ree course

The first set of tests involved pro%rammin% the Arduino me%a to travel for a set amount of time and

then preform a !?" de%ree turn* =i%ure F -!! displays the variation in the Arduino Me%as ability tocomplete the set task by plottin% all runs* All runs ere started at approximately -1*? m alon% the x-axis*The end position is shon to have a lar%e variation' ith the position ran%in% from approximately -> m to"*> m alon% the x-axis' ith the vessel both over and under turnin%*

The horiontal displacement is calculated by subtractin% the x-displacement of end of the turnin% circlefrom the x-displacement of the vessels final position* This value as the error of the individual run*Therefore if the vessel as to complete its turn at the intended bearin%' the horiontal distance ill be eroprovidin% the vessel does not drift off course hile travellin% in a strai%ht line* The data across all runs canbe found in =i%ure F -!(* The avera%e error amon% the number of runs conducted as found to be !*9> mith the measured error estimate ith 9> E confidence calculated as (*!! m*

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/i$ure >!&&: All runs or a &@9 de$ree trac8 /i$ure >!&(: Accuracy or a sin$le &@9 de$ree turn

=or the vessel to have !"" E accuracy ith no error' it ould re7uire the horiontal displacementbeteen the end of the turn and its final position to be ero*

>%( 1estin$ multiple turns

The second test re7uired that the vessel complete to turns durin% its operation' these turns ere both9" de%rees* The vessel as pro%rammed to travel for a specified time before makin% the first turn' afterthis initial turn the vessel as re7uired to travel for another set amount of time before makin% its finalturn* =i%ure F -!1details all the runs made* The vessel as not capable of completin% a successful runhere to consecutive 9" de%ree turns ere made*

The initial turn as found to have a hi%her accuracy than the second turn* This is seen in both =i%ure F-!Dand =i%ure F -!>*

/i$ure >!&+: all run testin$ the Arduinos ability to complete multiple turns

The accuracy of the first turn as found the alternate beteen -(> to !" de%rees as shon in =i%ure F-!D* The mean error of turn ! as found to be 9*"( de%rees ith the measured error estimate ith a 9> Econfidence interval bein% !F*G( de%rees*

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=i%ure F -!>details the vessels ability to complete a second turn' the vessel is seen to continue turnin%for a further (> to 1> de%rees* The mean error for the second turn as (G*>9 de%rees ith the measurederror estimated ith a 9> E confidence interval at ("*GG de%rees*

/i$ure >!&0: Accuracy o 1urn & /i$ure >!&=: Accuracy o 1urn (

>%+ Accuracy o the Ardu'M< V+

The accuracy of the ma%netometer and onboard calculated ya on the 0M# could be determinedthrou%h the use of the e7uipment at the model test basin' particularly the 2ualisys stop motion cameras*This as done thou%h post-processin% both sets of results and compared*

=i%ure F -!Fhas the accuracy of the ma%netometer shon as a percenta%e for all runs made ith thesystem ritin% the data to the* The error of the ma%netometer is very lo' alternatin% beteen "*> E to(*GE* @urin% these tests the vessel did not complete the turn once it had reached the specified bearin%'this hoever ould not affect the data from the Ardu0M# hence hy it can be compared to the 2ualisysresults* The ma%netometer had a mean deviation of !*DD de%rees ith the measured error estimated ith a9> E confidence interval at !*G1 de%rees

The data received relatin% to the ya had a much lar%er error ran%in% from (E to 1"E* =i%ure F -!Gshos the data for the Ardu0M# $1 calculated ya ith the measured error estimated ith a 9> Econfidence interval at >"*! de%rees

/i$ure >!&>: Accuracy o the ma$netometer on the

Ardu'M< V+

/i$ure >!&?: rror calculated or the ya* an$le as

calculated by the Ardu'M< V+

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=i%ure F -!? shos a comparison of the 7ualisys ya data' ma%netometer headin%' and Ardu0M# $1calculated ya* The 7ualisys and ma%netometer data are seen to follo a very close trend' hile theArdu0M# ya data be%ins to drift at the start of the test and continues to drift throu%hout the rest of therun*

0nitially the ya as ori%inally used as the reference data in the pro%ram' hoever the vessel ouldnot run the pro%rammed course* @urin% test alterations to the pro%ram ere made' hoever the Ba

ould not %ive results on any merit and vessel continued to not travel the envisioned path* As shon in=i%ure F -!9' the rudder an%le as bein% altered throu%h the entire run' hence hy it as turnin% ri%htinitially*

/i$ure >!&@: Comparison o the Ardu'M< V+ *ith data

rom the .ualisys motion capture cameras/i$ure >!&: Pro$rammed usin$ the 4a* to control

the #essels bearin$%

? 2iscussion6ith the use of both the Ardu0M# and ultrasonic sensor an autonomous vessel as achieved' the

vessel as able to avoid obstacles and complete a number of prepro%rammed turns* ;oever the vesselas not able to complete the intended turns to !"" E accuracy* The confidence of the results can beincreased by increasin% the repeatability of all runs for the individual tests*

The Arduinos accuracy as an autonomous is hi%hly dependent on to of the system components theArduino Me%a and the Ardu0M# $1* .oth systems sho a lar%e of error due to the pro%rammed functionsused in the system*

?%& Accuracy o the Ardu'M< V+

The to different sensors on the Ardu0M# caused a difference of results hen compared ith thoseattained from the 2ualisys system* The ma%netometer presented the results of hi%h accuracy bein% as loas "*F E and the measured estimated error bein% !*G1 de%rees* the ma%netometer has a hi%h accuracyhen compared to the results from 7ualisys'

The ya data bein%s to drift si%nificantly as soon as the Ardu0M# has been calibrated* This drift isthen translated throu%hout the rest of the test resultin% in the final ya an%le bein% si%nificantly differentfrom the actual ya an%le* This drift in the ya an%les caused the error estimate to be considerably hi%h&>"*! m) hen it could reflect a value similar to that of the ma%netometer &!*G1 de%rees)* 0f the ya an%leas to control the bearin%' it ould cause the vessel to over-turn or under-turn*

.efore the pro%ram as completed' it as found that by chan%in% certain properties in the code itselfould result in various inaccuracies of both the ya data and the ma%netometer data' the output modecorrects the ya data* 0f the output mode as selected the ya data ould be presented as normal but thema%netometer ould not display any results* 0f output mode as not selected then both the ma%netometerand ya data ould be displayed as normal*

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@urin% the pro%rammin% phase of the Ardu0M# $1' the parameter had to be set so the ra data fromthe %yroscope sensor as bein% sent throu%h the @CM matrix and then output as the ya' hile the datafrom the ma%netometer as not* The lar%e error of the ya data ould be a result of calculations of the@CM matrix*

?%( O#erall system accuracy

As the data from the Ardu0M#s ma%netometer as of hi%h accuracy' the vessel inability to completethe pro%rammed course is due to the navi%ation pro%ram implemented* Therefore the problem ill becaused by the navi%ation pro%ram that as loaded onto the Arduino and its control of the vessel direction*Once the vessel had reached its intended course the rudder as reset to allo the vessel to travel in astrai%ht line' hoever there as no pro%ramin% done to prevent the vessel from overturnin%*

.efore the 7ualisys system as calibrated for the boat' the vessel as tested6hen the ya an%le as used to dictate the end of the turn' the vessel as seen to have a hi%her error

hen compared to the ma%netometer* The actual path hen usin% the ya an%le did not match theintended path' ith the vessel not bein% able to be used for traversin% a strai%ht line* therefore on the day

=or both tests the vessel had a hi%h level error' ith the measured error estimate bein% (*!! m for asin%le !?" de%ree turn and

@ RecommendationsThe recommended pro%ram for the Ardu0M# $1 included code for readin% data from a 5S' the data

as read every ! second re%ardless of the stren%th of the 5S si%nal* As the 5S as disconnected' everytenth line of data as filled ith incomprehensible data' this re7uired the base code to be altered toremove all 5S code ithin the 0M# code* The 5S hen connected into the system ill also correct theya data' therefore testin% could be conducted here there is an unobstructed vie of the sky*

There are a number of accelerometers' %yros' ma%netometers' and 0M#s currently available on themarket' all of hich can be connected to the Arduino* As the sensors ould have varyin% accuracies'further testin% could be undertaken to determine hich sensor ould increase the overall accuracy of thesystem*

An H-bee module could also be added to the system to enable ireless communication ith acomputer' it ould allo the pro%ram to be uploaded irelessly and for all data bein% read from theArdu0M# to be sent directly to the computer*

=urther testin% needs to be done as only sin%le turn &!?" de%ree) path as repeated (D times and thedouble turn path as repeated !" times* The Ardu0M# $1 also re7uires further testin% hile bein%connected to an S@ breakout board as only ten runs ere completed for only one of the tests*

Conclusions3ven thou%h this is the initial sta%e of development' the Arduino micro-computer as used to create an

autonomous system that as capable of completin% a pre-pro%rammed course ith the use of an 0M#* .ymer%in% the ultrasonic sensor into the system' the vessel became a fully autonomous vehicle capable ofmakin% decisions based on its surroundin%s and headin%*

The system hoever did sho a considerable amount of error' resultin% in the vessel not bein% able tosuccessfully complete the pro%rammed course* Thou%h the Ardu0M# still re7uires additional ork to itscode' specifically the calculation of the ya data as ell as the accuracy of the accelerometer isdetermined*

The data from the ma%netometer can still be used to control the vessel due to the lo error of the data*The level of accuracy of the onboard ma%netometer shoed that this system is incredibly accurate'makin% it a %ood sensor to use hen collectin% data* The ma%netometer ould be ideal to be used as astand-alone sensor as the data has a hi%h accuracy ith an avera%e error of approximately !*> E

The vessel did not have any form of controller to dampen the vessels turn' once the vessel had reachedthe re7uired bearin% the rudder as reset to ero an%le of turn* This ould have caused the vessel to

!(


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briefly drift beyond the intended bearin%* Some form of 50@ controller ould cause the vessel to correctits ya an%le until it is travellin% alon% a constant headin%*

@ue to the number of repeated tests' the system could benefit from a %reater number of tests* 0f thesystem as to under%o further testin% it ould allo the data beteen the Ardu0M# and 2ualisys toanalysed ith less uncertainty in the error*

As the motor speed as controlled throu%h a potentiometer' the system ould benefit from the Arduino

motor shield as the pro%rammin% for the motor shield ould allo to the vessel speed to be varied fromithin the pro%ram*

The Ardu0M# $1 ould make an excellent choice as a stand-alone sensor for the determination of thecompass headin% and the direction of )* 0333*

.ahr' A*' +eonard' 4* 4*' I =allon' M* =* &(""9)* Cooperative localiation for autonomous underatervehicles*The !nternational 6ournal o% 5obotics 5esearch'/7&F)' G!D-G(?*Arduino* &("!1)* JArduino*ccK* Retrieved !D,"1' ("!1' Retrieved fromhttp:,,*arduino*cc,

Marport* &("!")* JA#$ Market to Reach L(*1 billion Over the


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AMC* &("!1) JModel test basinK* Retrieved (D,"9,("!1* Retrieved fromhttps:,,*amc*edu*au,maritime-en%ineerin%,model-test-basin*

2ualisys* &("!1)* Robust N hi%h performin% N real time* Retrieved (D,"9,("!1* Retrieved fromhttp:,,*7ualisys*com,products, *

.rittannica* &("!1)* 0nertial uidance System* Retrieved !G 4une' ("!1' fromhttp:,,*britannica*com,3.checked,topic,(?G1>D,inertial-%uidance-systemref?(11>(*

C;Robotics* &("!1)* #nderstandin% 3uler An%les* Retrieved (D September' ("!1' fromhttp:,,*chrobotics*com,library,understandin%-euler-an%les

Starlino* &("!!)* @CM Tutorial N An 0ntroduction to Orientation 8inematics' Retrieved (D September'("!1' from http:,,*starlino*com,dcmPtutorial*html

Ardu-imu' &("!")* Theory of operation &simplified)' Retrieved (D September' ("!1' fromhttps:,,code*%oo%le*com,p,ardu-imu,iki,Theory*

6ikipedia' &("!1)* 3uler an%les' retrieved (D September' ("!1' fromhttp:,,en*ikipedia*or%,iki,3ulerPan%les

!D
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a study into the application of the arduino mirco-computer for use as a navigation system

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