Olin Robosail User Guide
Contents
1. The Raspberry Pl receives sensor l NT aT data from the alaMode Setu p maintain fast sail angle 1 4 l point boat at target ch ll angle based tries to use the rudd j j cives Sani lyram i te ober e Plug all sensors into the Arduino A1 nit wind The alaMtod ives d ink quest Losses NO 5 Powerthe Arduino with an adequate L m power source A2 ail serna moves sail The Real World Rucker sere moves nidder i ino build and ino upload PubSub ino onto Arduino if it s not there A3 e Run the check arduino launch file A4 Will start Arduino lt gt computer communication e Rostopic echo the topics coming directly out of the Arduino A5 e heading gps lat gps lon pwm duration Making sure that an Arduino is getting sensor readings heading should be a number from 0 360 and should change when you spin the compass If you are seeing non linearity for example if the actual compass changes 10 and the reading jumps 180 then you need to run the compass calibration explained in the Calibration documentation gps lat and gps lon should be 0 inside and something like 42 288802 71 308823 outside You can check a site like http itouchmap com latlong html to check your actual latitude and longitude Use the tutorials mentioned in Index A11 to troubleshoot GPS issues pwm duration should be a n2. A Appendix A Recommended Hardware The components in Table 1 on page are recommended for a basic func tioning competitive sailboat NOTE We recommend the Aquacraft Vela as an RC boat because we have used and tested it as Mr Robateau s body There are a number of other RC craft that will work for this copmpetition Several things come with the Vela that you need to make sure you have if you get another RC boat e RC transmitter and RC reciever found at hobby stores or online e Servos that control the sails and rudder e Space for placing relatively waterproof electronics SOURCE A CONNECTOR FOR THE ENCODER AND INCLUDE IN THE TABLE Additional untested or unsourced things superbright LEDs nice wiring pack that can be worked with minimal tools recommended tupperware wa terproof connectors maybe cable clam maybe pneumatic connectors con formal 28 Name Rough Price Dollars Aquacraft Vela 350 00 Sailboat Raspberry Pi 39 00 AlaMode 50 00 Shield Edimax 20 00 EW 7711USn Wifi Reciever Adafruit GPS 40 00 3339 Compass 6 00 LSM303DLH LSM303 24 00 Breakout Board MA3 Encoder 30 00 wind sensor Water Leak 5 00 Sensor Total 960 00 Link lt http www amazon com Vela One Meter Sailboat 2 4GHz dp B004QJPSX0 gt lt http www element14 com community groups raspberry pi http www makershed com AlaMode for Raspberry Pi p mkwyi1 htm Compare Amazon
3. Figure 4 Wind vane assembled 5 Wireless Communication We recommend the Edimax wifi dongle with high gain antenna shown in Table l on page It is simple to connect to wifi through the Pi A great tutorial can be found on Adafruit s website lt http learn adafruit com adafruits raspberry pi lesson 3 network setup overview gt In order to emulate competition protocol the following router and wifi range extender is recommended as a similar setup will be used at competi tion Asus RT N66U Dual band Wireless N900 and Amped Wireless High Power Omni Directional 12dBi WiFi Antenna This allows us to accomodate boats that require b g n WiFi and teams are able to choose the type of WiFi they will use on their boat We recommend testing the range while on the water before selecting a bandwidth In general we have found that n has the lowest range but the highest capacity to carry data and b has a farther range than n but the lowest capacity to carry data Without the range extender wifi with the high gain Edimax has a maximum range of about 500 700 ft on land Maintain the wifi antenna mounted to the boat in a vertical position The antenna broadcasts orthogonal to the direction it points so if the antenna is 13 Figure 5 The silver marking was made after positioning the wire saddle on the wide plastic portion of the mast horizontal it will not broadcast a signal toward your computer see Figure 7 This is esp
4. A2 Powering the Arduino A3 Using ino to put code on the Arduino A4 Running a launch file Ab Using rostopic echo to query your code for information A6 What it means to publish data to a topic What are topics JA d TEI Tele A1 Plugging sensors into the Arduino You can see details about setting up and plugging in the Sensors section of the main Olinoboat documentation and also in the Quick Start guide Be careful with which wires are plugged where because if a wire is plugged into Digital Port 7 on the alaMode and the computer thinks it is plugged into Digital Pin 6 then whatever sensor is plugged into the wrong pin will not be seen at all by the computer A2 Powering the Arduino Powering an Arduino can be done a couple of ways From your computer via a USB cable Using 9V batteries with a barrel plug Using a DC adapter with a barrel plug This tutorial is rather old but it has lots of good pictures If you re interested in how to power the Arduino skip down to the Power Up section Ignore all instructions regarding jumper settings modern Arduinos like the very common Uno have no A3 Using ino to put code on the Arduino From the command line in Linux look through the Quick Start guide if that phrase is new to you you can build and upload code onto the Arduino using a set of tools called ino This is very useful in Linux and it is necessary when you start w
5. SDA Pin SCL Pin Port A4 Port A5 Now for the servo Plug the signal wire from the servo cable into D9 The servo has only three wires running from it pwr gnd and signal Signal wire Now let s plug in the encoder Signal wire And finally plug the power blocks in Take the loose wire you plugged into the gnd block and plug the other end into one of the two gnd ports shown below Do the same with the wire from the pwr block but plug it into the 5V port Gnd power pwr power block block un x 4 404 v3dV 5 Plug the SD card into the Raspberry Pi Just slide the SD card into the port on the bottom of the Raspberry pi as shown below 6 Plug the Raspberry Pi into the router then plug in first the aLaMode power followed by the Raspberry Pi Power Find a nice level non metallic surface near three outlets Plug the two microusb adapters included in the kit into two of the outlets Plug the included router into the third If for some reason you don t have the adapters you lost them or never received them most Android phone chargers will also work Now plug the pi into the router Any standard catbE Ethernet cable will work one should have been included in your kit However if you do not have one you can purchase one online on amazon com or any local electronics store Best Buy Radio Shack There should now be lights blinking on the raspberry pi the aLaMode and the GPS If you
6. commands the sail servo e Run sail calibration code explained in the Calibration documentation e Turn the encoder by hand and view the ROS log messages coming from maintain fast sail angle py as before but this time make sure the sail is going to that angle Make sure the suggested sail angle is correctly being turned into sail position This assumes you have checked the tests previously you know that the encoder is reading information that that information is being passed to the computer and that the computer is trying to set the sail to the correct angle If the entire above statement is true you should be able to just plug the servo in and make sure that it is going to the correct angles You can see what the wind angle is at any point along with what the computer thinks the correct sail angle is in the Log messages If the servo is moving but not to the right places you probably need to run the Sail calibration described in the Calibration documentation think tries to choose a heading that goes towards the waypoint without going into irons or directh downwind Make sure the sensor values are go fast outputs where go short outputs A corre ctly bei ng turn ed i nto not to go inta irons where to go at directly downwind waypoint suggested directions to go The Raspberry Pl receives sensor data from the alaMode Setu p maintain fast sail angle point boat at target chooses a sail angl
7. first try it on your computer if Arduino is installed in conjunction with an Arduino with which to test the sensors 3 4 4 Working from Windows or Mac If you are unable to install Linux directly on your machine Windows If you are running Windows you can run a virtual machine by doing the following e Download the code examples for the Arduino and debug ino files on a Windows machine e Follow the instructions in this document for installing Arduino on your computer download Arduino plug the Arduino into your computer point your computer toward the Arduino driver run blink e Note that to power the servos you will probably need to feed 9V through the barrel connector in order to claim 5V feeding 5V will provide a voltage of approximately 4 7V which might not be enough to drive a servo Mac HEY GUYS HOW DOES THIS WORK FOR MAC 4 Setting Up Sensors A successful robotic sailboat must gather and process information about its surroundings Specifically the boat must be able to sense its absolute location its heading and the direction of the wind To gather these data our boat Mr Robateau uses a GPS compass and wind vane Sensor recommendations can be found in Appendix A If you have already acquired all the reccomended sensors and want to get started right away go straight to our Quick Start Guide in Appendix Otherwise for descriptions of each sensor and tips for testing continue reading 4 1 Sensor T
8. The alamode fits snug on the top the raspberry pi as shown below 3 Make sure the power jumper on the alamode is in the off position The alamode can be powered either by the raspberry pi or through it s own power source When the jumper is in the on position first picture power comes from the pi When it is in the off position second picture it takes power from the microusb power port shown below or a battery explained later You will always want to power the alamode with it s own power source so the jumper should always in the off position If you don t do this then the sensors will not get enough power to run properly The jumper in the on position This is the position you do not want The jumper in the off position This is the position you do want The microsusb power port through which you will be powering the alamode There is also one on the raspberry pi which will also be used to power the pi 4 Plug in the sensors and the servo Now we need to plug in our sensors and our servo into the alamode through which they will communicate with the raspberry pi First the GPS Plug the wire from the TX pin on the GPS into the D3 port on the A La Mode and the wire from the RX port into D2 RX pin TX pin Next the compass Plug a wire from the SCL pin on the compass into port A5 on the A La Mode Then plug a wire from the SDA pin on the compass into port A4 on the aLaMode
9. boat to determine and mark the best placement see Figure L1p Remove the container and carefully trace the footprint of your box onto a sheet of paper Cut it out with a precision blade and check the fit of your box to that template Repeat until you reach the flanges of your box then tape the template onto the deck of your ship and cut it carefully If you are concerned about cutting into something you shouldn t have take a drill and drill a small hole through the deck first to see if it is made of fiberglass and wood or just fiberglass at that point To get past the foam layer underneath take a long utility knife or a carving knife and cut away at the styrofoam Proceed with caution and keep gloves on there is a sharp layer of fiberglass on top Mounting the rest of the electronics You should take the time to sketch out where you want your electronics to go Our plastic box was tall enough to mount the Raspberry Pi on the side 20 Figure 11 Place your container on the deck of your boat to find and mark optimal placement wall instead of on the bottom of the box Most of the electronics if not all can be mounted with velcro Try to minimize the number of exposed contacts use heat shrink if available and make sure all holes in the box are properly sealed You will most likely want to mount the GPS facing upward Here are some detailed pictures of Mr Robateau s electronics setup PUT PICS OF BOX HERE 8 Before Turn
10. if you set up the Raspberry Pi with a screen mouse and keyboard you can run Arduino code relatively easily Once you log in to the Raspberry Pi and type startx to begin the desktop mode simply start the Arduino IDE change the device to AlaMode change the Serial Port to dev ttyS0 and run your code Instructions and pictures can be found on page 8 of https docs google com document d 1HBvd3KNmcs632Zg06t _u37B qwV6P909FQe521GkumM If you are trying to run Arduino code from the Pi AlaMode combination without a monitor of some sort you need to follow the instructions in the next section The code package we provide should do this for you at a basic level venture into these areas if you wish to customize your computer 3 4 3 Arduino from Command Line The command line in Linux allows users to type commands that the com puter will run When you connect to your Raspberry Pi over WiFi you will not be able to see the screen immediately Instead you will be able to type commands that the Raspberry Pi then executes Read more about the command line at lt http linuxcommand org gt You can run Arduino code on the Pi AlaMode combination command line by using tools found at The easiest way to install the tools is using pip install ino and following any other instructions on the inotool website After installation of ino you can use the Quick Start Tutorial on their website to practice using ino A good way to test ino is to
11. in this library to calibrate the compass The compass must be calibrated so that it reads the correct values Fol low the steps in the callibration section of this guide INSERT PICTURE OF OUR FINAL COMPASS WIRING SETUP AND HOW TO SOLDER TO THIS 4 4 Wind Vane The wind vane is a homemade device based on an absolute magnetic shaft encoder see Appendix A that uses a Hall Effect sensor with a full 360 range The encoder we used on Mr Robateau is extremely low friction as it spins 10 using a bearing The encoder is recommended over a potentiometer because most potentiometers do not have a true 360 range they are usually about A0 shy Further most potentiometers wear out over time because their con tacts are constantly rubbing against one another unlike a magnetic encoder which uses no contact at all The encoder is wired as shown in Figure 3 The connector used is called a micro jst plug specific to JR servos You can also buy a pre wired 4 or 6 ft length of cable with this connector from US Digital but we found it more convenient to purchase multiple connectors and use spare PWM wire Note that these are all guidelines for you to get up and running Feel free to experiment with different shafts fin sizes materials et cetera You will need to make a fin with enough surface area to move the en coder as the wind goes by Cut a small fin shape from a rigid lightweight material such as styrene foam used for makin
12. on each latch 5 Check for any other water entry points ensure they are sealed e screw holes e seals around electronics container 24 e seals around pneumatic connectors bulkheads 6 Check the connectivity between devices e follow directions in the connections testing manual 12 Competition 12 1 Things to Expect Upon arriving at competition you should receive a packet of information including instructions about general setup and logistical information eg connecting wirelessly to the boat during competition the debugging center that will be available either a laptop with a console cable or a full desktop setup to plug the Raspberry Pi into schedule for the competition and various other pertinent details 12 2 Wireless Connectivity Be creative when naming your team s router perhaps use your team name in some way The competition router will likely be named something like RoboSail or RoboSail20xx so avoid similarly general names 12 3 Computers A main computer will likely be provided at competition 12 4 Prepare Cupcakes For optimal performance at competition for you and your boat bring a minimum of one dozen baked goods ideally cupcakes along Bake with care Patriotic decoration is preferable We understand that RoboSail judges tend to appreciate sweets 12 5 Maintenance and Repair Your boat will likely require some maintenance or repair over the course of any competition Your team can be pre
13. rudder calibration described in the Calibration documentation has been run which means the rudder should try to go to 45 full fo poe rex mx part carre Eee 3 2 Y MM vas anh Noulc ty irn tha abe rrt CUO VN M VV f PS d JL 0 d Os ww VU wv W 8 8 8 V E 8 V Vl B Sl Ww 2 EG wa ET We a er nrt U U LO
14. the article These were necessary for us We experienced an interesting problem in Arduino set up When using Arduino and trying to access the serial monitor the communication between the Arduino and computer often crashed This problem was solved by follow ing the advice given in Reply 3 by Pheaver on this Arduino forum arduino cc forum index php topic 126292 0 gt In summary there is sometimes an incorrect setting in an internal Arduino file when Arduino is in stalled on a Linux system The serial monitor allows users to see communica tion between the Arduino and computer An example use of the serial moni tor lt http learn adafruit com adafruit arduino lesson 5 the serial monitor 3 4 AlaMode Setup The user manual for the AlaMode can be found here lt https docs google com document d 1HBvd3KNmcs632Zg06t_u37B qwV6P909FQe621GkimM This contains useful information about how to set up your AlaMode there is a little soldering involved how to power your AlaMode and more 3 4 1 Installing Arduino and Proper Settings HOPEFULLY NOT NECESSARY OUR RASPBERRY PI IMAGE SHOULD HAVE THIS ON IT This guide provides useful instructions for installing Arduino with the proper settings AlaMode Getting Started lt http wyolum com projects alamode alamode getting started 3 4 2 Running Arduino on Raspberry Pi When you have Arduino code written on the Raspberry Pi you can run it one of several ways First
15. value to SensorOffsets txt e Servos Lay a protractor over the rudder with 90 pointing directly back wards Use the left and right arrow keys to turn the rudder to 45 Press q to lock in the rudder servo s minimum angle Repeat for 90 and 135 22 Use the up and down arrow keys to let the sail all the way out to 90 from the boat press q to lock in the sail s maximum angle Repeat for a sail angle of 0 The code will write these values to SensorOffsets txt Compass Rotate the compass all the way about each of its three axes The code will capture the xmin xmax ymin ymax zmin and zmax values and write their values to SensorOffsets txt GPS The GPS requires no calibration It outputs latitude and longi tude data out of the box The conversion to UTM happens after data is acquired When data comes in from the sensors or is sent out to the servos it will be calibrated according to these values check out sensors py and servos py for the implementation In a perfect world you would only need to calibrate your boat once However it is important to check that your sensors are publishing the values you expect and recalibrate if necessary 10 Testing Your Code Whether you are writing you own code or simply testing your system with the supplied Olinoboat code you must be able to walk through each step of the code and test it at each point This both lets you know ex
16. with a maximum pointing at the next waypoint go fast py will have a thick wedge pointing upwind and a thin wedge pointing downwind think py will be the combination of those two graphs When you rostopic echo desired heading you should see a value from 0 360 and it should correspond with the highest point on think py Make sure the sensor values are correctly being turned into suggested directions to go cont If go short is all zeros the polar graph is all white it could be because you don t have any GPS data You can plug in the GPS to get real data or create simulated data with rostopic pub 1 gps latstd msgs Float64 0 0 rostopic pub 1 gps lon std msgs Float64 0 0 This will make your boat think it is at O latitude and O longitude If you set up a mission in mission file csv Index A14 the code should then have data for go short If go fast is all ones there is a blue ring on the polar graph it s most likely because you don t have wind data Either plug in the encoder or test it if it s in or create simulated data with rostopic pub 1 pwm duration std msgs Ulnt16 128 This is on a 0 1023 scale where 256 is 90 512 is 180 etc This should make your boat see an apparent wind which should give go fast enough data to work with think tries to choose a heading that goes towards the waypoint without pointe kone oc det dowd Make sure the suggested direction uum to go is turned into the correct go
17. Newegg and or Walmart for online lt http www adafruit com products 746 gt lt https www sparkfun com products 9757 gt lt https www sparkfun com products 10703 gt lt http www usdigital com products ma3 gt lt http www parts express com pe showdet1 m partnumber 320 122 O go kh T m O D NM Table 1 Recommended set of base hardware 29 B Appendix B Recommended Tools and Ma terials A number of basic tools and other materials will aid in the set up of the boat C Dremel and sanding wheels Phillips head screwdriver flat head screwdriver precision blade i e Xacto knife and spare blades utility knife and spare blades metal straightedge or ruler epoxy with disposable cups spoons and brushes Super glue aquarium sealant Vaseline safety glasses gloves what kind dust masks power drill hot glue gun with glue soldering iron with flux thin solder et cetera heatshrink wire stripper wire cutters unless the stripper has cutters on it Appendix C Quick Start Guide 30 Lets get you up and going This tutorial will help you setup and test the included hardware and software It will also give a quick introduction to the organization of the software so you can start writing your own code Things you ll need 1 SD card with the included ROSbian image installed on it This should have been included in your kit However if you did not receive one or h
18. Robosail User Guide Rev 3 David Gaynor Trevor Hooton Eric Schneider Brittany Strachota Adela Wee Advised by Andrew Bennett and Bradley Powers April 26 2013 Abstract This document aims to provide basic instructions and recommen dations sufficient to guide a high school team through the process of making a robotic sailboat for the RoboSail competition sponsored by US Sailing Basic hardware and software setup instructions as well as troubleshooting and competition advice are included Provided software and further instructions are designed to provide basic func tionality students can pursue further enhancements to improve their boat s capabilities or performance 1 Introduction 1 1 Executive Summary Over the past two decades high school students have been inspired and en couraged to pursue further education or careers in science and technology through competitions like the FIRST Robotics Competition FRC FIRST Tech Challenge FTC and SeaPerch Although many of these participants go on to pursue careers in technical fields a recent study by the National Science Foundation NSF showed that the United States produced only 10 of the 5 million engineers who graduated in 2008 7 We have developed a robotic platform for use in RoboSail a high school autonomous sailing competition sponsored by US Sailing designed to take advantage of dropping hardware costs and increasing focus on encouraging our youth to pursue a car
19. S sent x y 31352 12341 Which came from this command in the code rospy loginfo go short py GPS sent x y 96f f 96 boat x boat y A10 Plugging servos into the Arduino In general this is how servos are wired http www fatlion com sailplanes images futabaconnector pn Black or Brown Goes to ground Red in the center Goes to power usually 5V White or Orange The signal line The alaMode is currently set up so that the Rudder signal line is on Digital Pin 9 and the Sail signal line plugs into Digital Pin 10 You can see more about setting up the A11 Getting and checking GPS data This is the type of GPS recommended by the Olinoboat team http www adafruit com products 746 Description This is the beginning of the tutorial for the GPS http learn adafruit com adafruit ultimate gps The Direct Computer Wiring link at the bottom of the page will take you to the next part of the tutorial that can be somewhat unclear This tutorial can be done with an Arduino and the GPS A12 What go fast py and go short py are doing The programs go fast and go short try and do simple tasks but the way that simple task is done can be a bit hard to grasp go fast looks at the apparent wind angle then tells the boat it should not into irons or directly downwind As of 04 25 13 that means it doesn t want to go within 50 on either side of the wind angle or within 10 of directly downwind These numbers ca
20. actly what the boat is doing at each point and also lets you ensure that what the boat is doing is correct Appendix D delineates a series of tests that will help you determine what the code is trying to do These tests assume that your roadkill is set up and plugged into an Arduino as you will see in the appendix The Communica tions Testing guide also assumes knowledge from the Quick Start guide and 29 the ROS tutorials so in going through the tests you may need to learn a few new things You will run into strange unforeseeable problems while testing and will need to find your way out of them Looking to the internet for help is never a bad idea as a first step Best of luck 11 Pre sail Checklist There are several checks and other measures that must be taken before each time the boat is launched on the water including but not limited to the following 1 Check battery voltage e voltage should be above 7 4V for a 2 cell LiPo or 11 1V for a 3 cell LiPo 2 Check battery connector seals e make sure you cannot see the terminals and that you cannot push the connectors any closer 3 Ensure mast is secure e post in depression e ensure stays are tensioned properly which in general means tight ened evenly to the point where there is no slack in the stays but they don t hum when plucked 4 Latch all hatches securely e position such that seals are properly aligned e perform a light tug test
21. ave lost it check out the guide Installing ROSbian before continuing 2 Raspberry Pi This will be the brain of your Sailbot It will process the sail position GPS position of the boat wind speed and heading and then decide how to move the rudder and Sails 3 A La Mode Board This board plugs in to the top of the raspberry pi we ll show you how and allows the pi to communicate with all the sensors and servos aboard the boat 4 Pre wired GPS module This board detects the GPS position of the boat with an accuracy of 10m So if you were to take the boat to your house this module would tell the boat which room it was in although it would not be accurate enough to know where in the room it was Using this your boat can navigate to waypoints you define and avoid obstacles you tell it avoid We recommend the Adafruit ultimate GPS breakout board and the pictures and descriptions in this guide will refer to that device This board comes pretty much set up but you will still need to solder wires to 4 of the leads on the board before using it If you have not done this already check out the Assembling the Sensors guide before continuing 5 Pre wired compass module Although this may not look like any compass you ve seen before it still works pretty much the same way This sensor will tell your boat which way it is facing North South East West and anywhere in between It will let your boat adjust heading into o
22. do not see any lights make sure that the micro usb cables are plugged in securely both to the wall outlet and the boards Also make sure the outlet you are using works by plugging something else in and verifying it works Getting started with the software Once you get the lights blinking on the raspberry pi GPS and aLaMode you are ready to get started with the sailboat software If the steps below will include screenshots from the pre configured VM from website If you are not using that VM but still followed the Setting up Linux for Rosbian Development things might look a bit different but all the commands should work the same 1 Boot up your Linux machine if you don t have this consult Things you need number 8 2 Openaterminal window You will be using the terminal often while developing for code for the Sailbot You will use it to run ROS locally on your linux machine for testing and also to communicate with the Raspberry Pi and run ROS there ROS is the software at the core of your Sailbot s brain You don t need to worry about how it works unless you re interested Most of the time you will be editing code which communicates with ROS we will explain this later but you will never have to do anything too complicated with it 3 ino 0 3 5 tar gz t Web Browser Mail Reader Settings R Accessories Development Electronics oh Games Graphics Internet T Mukimedia W Office o System Ubuntu S
23. e based T tries to use the rudder e Plug all the sensors into the Arduino on th to point the boat where apparent wind The slaModa recelves data eS tot tees Power the Arduino with an adequate g il servo moves sail The Real Warld Rudder servo moves rudder power source e ino build and ino upload PubSub ino onto the Arduino if it s not there e Go outside to get GPS data A11 Run the check_think_code launch file Will start Arduino lt gt computer communication e Will run go fast py and go short py which suggest headings to go A12 e Will run think py which chooses a direction to go A13 e Will run py to graph the output of the think code Look at the graphical output and see if it is correct In How Robateau Thinks you can find information on how these graphs work Rostopic echo the topic coming directly out of think py to get the final heading being suggested to the boat and see if that is correct e desired heading Make sure the sensor values are correctly being turned into suggested directions to go This assumes you have done tests 1 and 2 the computer can see all the correct sensor data Inside of How Robateau Thinks documentation you can see pictures of what go fast py go short py and think py should all look like In general this will make more sense when you look at the pictures go short py will create an oblong oval
24. ecially important to consider when waterproofing the dongle We recommend coating all connections in a long cure epoxy specifically West Marine s West Systems 105 Epoxy Resin and 205 206 Hardeners 206 is slower and is a bit easier to deal with Be sure to coat all joints and points of connection sufficiently see Figure B Note that non 5 minute epoxies have a stage in the curing process in which they are flexible and can be easily 14 Figure 6 Wire saddle mounted to the mast trimmed with the use of an x acto utility knife The WiFi dongle has a moving joint be careful not to get any epoxy on it Also be sure it cannot be twisted off that is another area that is prone to leaks and if properly cured if you try to twist it off the lower joint of the antenna will pop off instead This is actually desirable as it will allow you to silicone the inside because if water got in there as well it would wick down into the board and potentially destroy the dongle The silicone allows for the antenna to remain flexible even after curing 15 Figure 7 Antenna in proper position before applying epoxy 6 Radio Controller The Vela model boat comes packaged with a two channel transmitter and receiver RC remote However for autonomous operations you may find that it has an insufficient number of channels We highly recommend each team purchases a receiver and transmitter made by either JR Spectrum or Futaba with at least four chan
25. eer in STEM science technology engineering and math fields This platform is meant to serve as a low cost kit that will al low students to develop a unique solution to the challenge of the competition with appropriate scaffolding to ensure some measure of success regardless of a team s access to additional resources The platform includes a one meter model sailboat sensors and other hardware critical to the boat s autonomous operation and a library of back end software that students can use to bench test sensors and quickly develop their own code 1 2 Problem Space and Mission This low cost robotic sailboat platform provides students an opportunity to develop technical and life skills as well as synthesize and apply facets of their knowledge base We hope the project will allow students to foster an interest in technical fields build valuable relationships practice practical skills pub lic speaking teamwork professionalism problem solving and tie together aspects of business fundraising budgeting marketing with applied math and science The SailBot collegiate autonomous sailboat competition sponsored by US Sailing was first held in 2006 and has grown every year since The program is at a point in its lifecycle that is conducive to expansion into the secondary school market Successful high school robotics have drawn over 45 000 high school stu dents into the arena of robotic competition bringing professional
26. esting We recommend assembling a roadkill that includes all hardware laid out on a board for testing Affix the components to a rigid nonconductive i e Sintra Lexan acryclic board with tape laid out and labeled for clarity see Figure D REPLACE WITH PHOTO OF NEW ROADKILL REPLACE WITH PHOTO OF NEW ROADKILL 4 2 GPS The recommended GPS see Appendix A is fairly accurate 2 5m and re quires a battery to run The GPS has a database of satellite location in formation that it runs through when first booted up also known as a cold start and uses the battery to store its last recorded location so that it will be usable sooner An Arduino tutorial for GPS is here ep p g AS SOON AS WE GET OUR CODE BASE ORGANIZED WE SHOULD REPLACE THIS WITH OUR OWN CODE ALREADY LOADED ON THE PI INSERT PICTURE OF OUR FINAL GPS WIRING SETUP AND HOW TO SOLDER TO THIS 4 3 Compass The recommended compass chip see Appendix A is a triple axis magnetic sensor with a triple axis accelerometer for tilt compensation very useful on Figure 2 Mr Robateau s completed roadkill with all components for testing a boat rocking in the waves propelled by a force that pushes it over The math used to process all this data is fairly complicated but a code library written by GitHub user ryantm converts the raw output of the compass to a heading from 0 to 360 see lt https github com ryantm LSM303DLH gt Use the most current files
27. fast outputs where go short outputs nat to go into irons where to go at 1 suggested rudder angle directiy downwind waypoint Setup The R be Pi r i amp C aata on henkie e Plug all the sensors into the Arduino maintain fast sail angle point boat at target Cho nsa a ssl angle based T tries to use the rudder e Power the Arduino with an adequate on that to point the boat where apparent wind The alaMtode receives data think py requests power source from the sensors a e _ i e ino build and ino upload PubSub ino C TERRE onto the Arduino if it s not there Go outside to get GPS data e Run the check rudder control launch file Will start Arduino computer communication Will run the think code go fast go short think Will run point boat at target py which tries to point the boat at the desired heading using the rudder e Rostopic echo desired heading from think py to see where the boat is going View the ROS log messages from point boat at target py which look like point boat at target py rudder angle is being set to 30 This means the code wants to turn the rudder to 30 degrees 30 deg CW Make sure the rudder angles that are being set will turn the boat towards the desired heading turn the compass and check that it changes correctly A15 Make sure the suggested d
28. g model airplanes or cardstock wrapped with duct tape Attach this to a small about 4 length of wire with a small amount of durable tape We used 1 32 carbon rod on Mr Robateau but an unbent paperclip would also suffice Poke a small hole through a coffee stirrer tube shaped material that fits over the end of the encoder shaft and push the wind vane through it We used 1 8 diameter aluminum tube and placed shrink tubing over the hole to hold the vane snugly see Figure 4 The encoder should be mounted carefully near the top of the mast such that it does not interfere with the sails motion and can catch a true sample of wind We used a wire saddle to mount the encoder in its waterproof case see the Waterproofing section of this guide Mark a mounting hole after posi tioning the saddle on the wide plastic portion of the mast see Figure 5 Drill a hole in the center of the marking to accommodate mounting hard ware and attach the wire saddle to the mast see Figure 6 The waterproofed encoder fits into this mounted wire saddle 11 Figure 3 Encoder wiring Note that the encoder has a full 360 range but it is impossible to discern the beginning and end of it from the outside It is likely that the encoder will not be installed straight However any offset error can be accounted for in software On startup simply set the vane pointing in the direction you wish 0 to be and run the calibration script 12
29. he servo wiring etc If instead you plug the wind sensor into your computer you can easily check that 1 the sensor data is reaching the computer 2 the code is choosing to do the right thing with the sensor data and finally 3 that the sail servo is moving to the right place How to use the Index The suggestions we make in these slides and commands we suggest running may be unfamiliar to you like Rostopic echo the topics you care about so we have tried to tried to create an index at the end explaining various steps If a topic is in the index we will mark it like so Topic of interest A1 Another topic of interest A2 The index will either try to explain the topic or point you to other resources in our documentation If a confusing suggestion is not marked as a topic it was probably marked in an earlier slide if it came up before and you will likely be able to find it in the Index How to use the Results Slides After each test slide you ll find a results slide that will try to explain what information you should be seeing These slides will also try to give you some ideas for solutions if you re not seeing the correct thing think tries to choose a heading that goes towards the waypoint without going into irons or directhy downwind ga me Making sure that an Arduino is go fast outputs wh go short output i Ere reru getting sensor readings directly downwind waypoint
30. he tube Drill a hole just a little larger than the encoder shaft in the cap Fit the encoder in making sure the mini jst plug is in place Fill the tube with petroleum jelly reattach the ends and apply either hot glue or silicone sealant to both ends Some excess petroleum jelly will probably come out of the drilled hole for the encoder shaft see Figure p Wipe this excess away from the shaft a small amount will not hinder mobility or performance Drill two holes into the plastic on top of the mast and use a ziptie to hold it in place z Figure 9 Top of encoder capsule with excess petroleum jelly coming out of drilled hole for encoder shaft Wipe this excess away Mounting the Encoder to the Mast Things you will need The completed waterproof encoder assembly and a similarly sized holder for electrical cabling like a cable clamp or saddle tie Attach the mount to the encoder assembly and mark the hole on the mast 18 Figure 10 Bottom of waterproofed encoder capsule through which you aim to mount it Drill out this hole and fix it in place with a nut and bolt Run a cable tie through or if it is the one piece you are done INSERT MOUNTING ENCODER PICTURE HERE Mounting the Brain Things you will need A locking sealing plastic box 3 5 oz or so silicone sealant velcro hardware 3 8 quick release pneumatic connectors flexible 3 8 pneumatic hose a small amount of Duct Seal a k a monkey dung 5 pin Wago 222 con
31. ing On The System Checklist Here are some things you should make do before powering up your roadkill 1 LABEL ALL WIRES 2 Check wiring e Power and 5V are plugged in to terminal blocks e BEC 5V regulator is plugged into terminal blocks e Was BEC programmed to 5V you can easily check this by using a voltmeter to measure the output voltage e Wires plugged into 5V are not also plugged into ground 3 Reduce risk of killing electronics 21 e Are all boards in cases insulated in some way e Did you ground yourself wear a grounding strap before handling electrical components 9 Calibration Guide When your hardware is mounted on the boat and you have completed the Quick Start manual found at the end of this document ensuring your sen sors are publishing data and your servos respond to your commands you are ready to calibrate your robotic sailboat The purpose of calibration is to align your sensor outputs to the real world phenomena they are measuring For instance it is practically impossible to install the encoder such that the 0 value points straight ahead It is quite simple however to determine what the offset actually is and subtract it from the measured value later To calibrate your hardware follow this procedure e Start SSH in to the Pi and run calibrate launch to begin the calibration protocols e Encoder Point the wind vane directly forward to set the 0 value The code will write this
32. irection to go is turned into the correct suggested rudder angle Index A15 How you know what the rudder position should be tells you what to expect from the commanded rudder setpoint Because the rudder depends on the output of think py you can rostopic echo desired heading to check where think wants the boat to go then spin the boat by hand and make sure that the rudder is resetting as the compass direction changes You can check the correctness of the rudder setting using A15 If this is not doing what you expect you may need to dig back into what think py is doing then go short and go fast then all the way back into the GPS and compass values As you get errors farther and farther out in the code you need to work your way back through every intermediate step to double check everything think tries to choose a heading that goes towards the waypoint without lb Make sure the suggested rudder enn EN angle is correctly turned into rudder xtate Deed movement directly downwind waypoint ipm Setup dB Plug all the sensors into the Arduino chooses ssi age tases t ies touse ihe d and the rudder servo apparent wind The alaMode receives data thinkpyrequests e Power the Arduino with an adequate Sail servo moves sail The Real World from the sensors power source e ino build and ino upload PubSub ino onto the Arduino if it s not there Go
33. log inputs and fourteen digital inputs outputs which is sufficient for a robotic sailboat with three or four sensors and a pair of servo motors There is a wealth of support for and information on the Arduino Uno on arduino cc and the AlaMode on Wyolum s website see 13 Arduino code is written in C or C and data communication to and from the Pi uses ROS However for the purposes of this project all of this basic code is provided You can treat the AlaMode as a black box Plug all the sensors in and run code in Python don t worry about the nuts and bolts in between unless you have a special interest in the inner workings ADD SPECIFICS ON HOW IT IS USED FOR THIS BOAT 3 Beginning Steps for Students Here are a few short tutorials to get you and your team up and running 3 1 Installing Linux The Raspberry Pi runs Linux so it is much easier to develop code in a Linux environment than through a PC running Windows or Mac An advantage is that most pre written snippets of code you will want and need will be far easier to download in a Linux system than in Windows Skip this step if you do not want to install Linux One of the easiest ways to begin running Linux is with a virtual ma chine You can find details and instructions for doing that with Linux here lt http www psychocats net ubuntu virtualbox gt Install the latest version available The virtual machine installation process is summarized in this guide in the Wo
34. n S ae a i PUER Ber rp c mee N escam sU bee eee penne IUE DERE a 4 r rj rryago y a eh b f 1 a m nar E A 3 rY C IC Clid iI 29 JV OL IOGI Ledis a wi B WES B P w y C WE 8 uu 8 ua wl 8 B Ee A13 What think py does This the documentation at the top of think py think py creates a loop that calls other code H Dependent on go fast py go short py think py takes the outputs of go fast and go short multiplies them together and then chooses the strongest element as the heading to go to See code explanation documentation for a more in depth explanation of the arbiter A14 How are missions set with mission_file csv Inside of the upper level Olinoboat folder there should be both mission_file csv and mission file csv howto txt The txt file explains how to set waypoints for the boat using mission file csv Here is the overview nside of mission file csv you should see something like A c 2 oe Hou EDU TEN Dx pur pee pe i a s end DR ENMEP ER A15 How you know what the rudder position should be As of 04 25 13 the rudder is set to try and point the boat at the desired compass heading That means if the boat is pointing South and the heading is West the boat needs to turn 90 assuming that North 0 and degrees increase clockwise as all of the Olinoboat code assumes The rudder is stopped in code from going more than 45 to either side assuming that the
35. nd waypoint The Raspberry Pl receives sensor data from the alaMode maintain fast sail angle g k chooses asail angle based j on the apparent wind The alaMode receives data m from the sensors Setup point boat at target tries to Ust tha rudder e Plug the encoder into the Arduino to paint the boat where go Hr cocoa a e Power the Arduino with an adequate power source The Real World Ruger sema moves nidder ino build and ino upload EncoderRead_RosPub ino onto the Arduino Sailservo moves sail e Run the check sail control launch file Will start Arduino computer communication Will run maintain fast sail angle py which looks at wind encoder data and commands the sail servo Spin encoder by hand to an angle you know the correct sail position for A8 and check with Log messages A9 that program is trying to set the correct sail angle Look for Log messages from maintain fast sail angle py which look like so fast sail angle py sail angle should be 60 This means the code wants to set the sails 60 degrees out is that correct for the current encoder angle Make sure the sensor values are correctly being turned into a suggested sail angle Index A8 How you know what the sail position should be tells you what to expect from the commanded sail setpoint Because the sail position is set by the apparent wind you can spin the encoder to differen
36. nectors to act as a power distribution block Alternatives to pneumatic connectors bulkhead IP 67 cables made by Adafruit Highly recommended tools Dremel with cutting disks sanding drums and drill bits 19 One does not need to cut a hole in the boat to fit the box but it is im portant to consider that the higher the center of mass the more likely the boat is to tip We cut a hole in Mr Robateau s deck so we could situate the electronics as low as possible keeping the center of mass low For any boat the relation of the center of mass to the center of buoyancy is extremely important and generally you want the distance between them to be as great as possible A low center of mass will be most stable Cutting a hole in the deck WARNING Fiberglass is an irritant and can harm your lungs Before cut ting ensure you have the proper safety gear including a dust mask safety glasses thick gloves and a labcoat long sleeved shirt or jacket Make sure your skin is protected covered before sanding grinding or cutting into the boat s hull The Aquacraft Vela includes a support for one of the stays that may need to be removed in order to cut a slot for the box Proceed with caution watching for the piece of plywood that runs underneath the deck behind the mast to distribute the load from the stay that was just removed It is okay to cut into some of it but minimize the material removed Place your container on the deck of the
37. nels Additionally you may need the four channel mul tiplexer from Pololu see Table 1 on page in order to switch between teleoperation and autonomous control If all channels are connected you can have full autonomous or full manual control If you require one channel of autonomy and one channel of manual control autonomous sail and manual rudder you can function at a base level by plugging the sail servo into the multiplexer If you require a farther range via remote control you can replace the 16 Figure 8 Coating connections in epoxy Be sure to coat all joints and points of connection 2 4Ghz hardware with a 900Mhz version Note that most boats only come with two servo channels rudder and sail If you desire greater control over your boat you may need to acquire a receiver and transmitter with more than five channels 7 Installing Hardware on the Boat 7 1 Waterproofing Before putting anything out in the water all of your equipment must be splash proof and relatively dunk proof too Here are a few tutorials de tailing Mr Robateau s waterproofing Waterproofing the Encoder The encoder needs to be waterproofed and mounted to the mast You can 17 use anything from a large diameter straw to an empty lip balm tube to water proof just make sure the ends are sealed You will probably need an empty lip balm tube petroleum jelly silicone sealant and maybe a popsicle stick First cut off the bottom of t
38. o into irons where to go at directly downwind waypoint The Raspberry Pireceives sensor data from the alaMode maintain fast sail angle j point boat at target chooses a sail angle based tries to use the rudder on the to point the boat where apparent wind The alaMode receives data think py requests from the sensors Sail servo moves sail The Real World Rudder servo moves rudder Figure 1 Completed roadkill with all components for testing The Raspberry Pi uses a Linux operating system so users must learn how to use bash command line Linux is open source and plentiful documen tation is available online see 5 The think code is written in Python a relatively straightforward programming language again with plentiful docu mentation online Communication between devices and nodes of code for storing and transferring variables and data uses ROS Robot Operating Sys tem 8 a communications protocol specifically designed for robotic systems with multiple asynchronous processes such as this one 2 2 Arduino The Arduino microcontroller is widely accepted as one of the easiest ways to bridge the gap between computers and the real world Wyolum an interna tional group of hardware tinkerers decided to take this open source hardware and reconfigure it for the Raspberry Pi The Arduino device is aptly named the AlaMode as it is designed to sit atop the Raspberry Pi The AlaMode has six ana
39. oftware Center P Help ir About Xfce 2 Log Out mission catcher py sensors py servos py b programming toot NOTES FOR DOCUMENTATION fake gos goal py fake gps listener py get headings py groovy workspace src olinoboat sci Preferences Help Goto Tools Project EM Run Program Application Finder roslib r dm Archive Manager bpython F Calculator math Catfish programming E Character Map a File Manager OE sedr E Leafpad Notes a Onboard Orage Globaltime Orca Screenshot qe Screenshot Sublime Text 2 M Terminal Emulator xdiagnose xtum Terminal dgaynorfubuntu Fe Ede View Termmal Go Help dgaynortubuntu 3 Type in the command ssh pi rosbian and press enter You may see a warning like The authenticity of host rosbianl olin edu 10 33 26 32 can t be established ECDSA key fingerprint is bl 56 1e eb5 87 fa 9d 0d 2f 57 46 eb 53 41 1c 7e Are you sure you want to continue connecting yes no In which case just type yes and hit enter You will now be asked for a password The password is raspberry Type that in and hit enter 4 You will now see these lines in your console Debian GNU Linux comes with ABSOLUTELY NO WARRANTY to the extent permitted by applicable law Last login Tue Apr 23 11 10 58 2013 from 10 41 24 174 pi rosbianl The raspberry pi also runs a version of linux whose console operates the same way that the console on your ver
40. older src which is inside the folder catkin ws which is inside the folder cding into a folder like we just did is just the same as double clicking the picture of a folder in windows explorer So now type the command Is again and you should see this or something like it ls bag Launch calibrate launch mission_publisher_test Launch blink launch hello launch teLeop Launch So there are no folders in this directory no purple words So all these names must be names of files To get you started we re gonna run one of these files we ll do this by running the command roslaunch calibrate launch You might have to wait for a minute but then you should see some text print out on the console Now go ahead and follow the Calibration Guide D Appendix D CommunicationS Testing with Arduino 45 The point of this Guide In these slides you can follow high level steps to walk through and check each step of the code This will hopefully let you 1 Test your system and confirm that it works OR 2 Narrow in on the points in your system that are not working While this guide will try to give suggestions for what might be going wrong in your system we can t cover the entire range of problems that might be raising issues here Hopefully this will help you identify problem areas at the very least Best of luck The Olin Robo II Team Rough upper level think tries to choose a heading that Code diagram goes towa
41. omputer communication e Will start publishing the visible sensor data A6 e Rostopic echo the topics holding the processed sensor data A7 e compass heading y position UTM x position UTM wind angle Making sure the sensor values are being reported accurately to the computer from the Arduino The comments here will assume that the last test worked and that the sensor values are accurately coming off of the Arduino onto the computer compass heading should be from 0 360 the exact same as heading y_position UTM and x_position UTM should be the longitude x and latitude y from the GPS converted into UTM Wikipedia UTM for a good description You can use a site like this http tagis dep wv gov convert To check whether your latitude and longitude is correctly showing up as UTM The actual conversion from lat lon to UTM occurs in latlon tools py wind angle should be from 0 360 and change when you spin the encoder The computer has taken the 0 1027 scale of the raw data and converted it to a 0 360 scale If the wind vane is mounted on the boat and the 0 position of the encoder is not dead ahead you can run the encoder calibration mentioned in the Calibration documentation think tries to choose a heading that goes towards the waypoint without going into irons or directly downwind pee is N Make sure the sensor values are ren Mere correctly being turned into a suggested sail angle directly downwi
42. orking with the Raspberry Pi which usually only has a command line interface You can download the ino toolkit for your computer here http inotool or The pip install ino command is easiest A4 Running a launch file Launch files are a good way of running multiple ROS programs at once If you ve done been doing the tutorials for ROS www ros org wiki ROS Tutorials you will run into this introduction to roslaunch http www ros org wiki ROS Tutorials UsingRqtconsoleRoslaunch Scroll down to the 1 2 2 Using roslaunch section specifically To work with the code you should really go through the introductory ROS tutorials they are relatively simple and there is a large community with FAQs that can help J 11 AZ C WAr WI rc ihre AJ Yl j M mpi id LS yuu UN AS qT MAT ua unte Jee s Ab Using rostopic echo to query your code for information Topics are the main way of passing data around in ROS and rostopic echo is a way that the programmer you can view what is currently on a topic If you ve done been doing the tutorials for ROS www ros org wiki ROS Tutorials you will run into this introduction to rostopic www ros org wiki ROS Tutorials UnderstandingTopics A6 What it means to publish data to a topic Topics are the main way of passing data around in ROS If you ve done been doing the tutorials for ROS www ros org wiki ROS Tutorials you will run into this introduction
43. outside to get GPS data Rudder servo moves nidder Run the check rudder control launch file Will start Arduino computer communication Will run the think code go fast go short think Will run point boat at target py which tries to point the boat at the desired heading using the rudder Run sail calibration code explained in the Calibration documentation View the ROS Log messages from point boat at target py as before but this time make sure the sail servo is going to that angle You can turn the boat or just the compass by hand and check whether the rudder reacts in the right way Make sure the suggested rudder angle is correctly turned into rudder movement This assumes you have checked the tests previously you know that the sensors are reading information that that information is being passed to the computer that the think code is choosing reasonable headings and that the computer is trying to set the rudder to the correct angle If the entire above statement is true you should be able to just plug the rudder servo in and make sure that it is going to the correct angles You can see what the desired heading is at any point along with what the computer thinks the correct rudder angle is in the Log messages If the servo is moving but not to the right places you probably need to run the Rudder calibration described in the Calibration documentation INDEX A1 Plugging sensors into the Arduino
44. pared for most fixes with a handful 29 of important things set of screwdrivers e spare quick setting waterproofing sealant silicone rubber tubing hot glue e strong tape e spare batteries and charger e patches for sail and hull of boat 26 References Adafruit Online Available lt http learn adafruit com i video output using pygame overview http learn adafruit com adafruit ultimate gps direct computer wiring AlaMode purchase Online Available http www makershed com laMode for Raspberry Pi p mkwy1 htm Ns 3 Common Core State Standards Initiative Online Available corestandards org gt 4 FIRST Online Available 5 The Linux Documentation Project Online Available ldp org 6 Understanding RC LiPo Batteries Online Available rchelicopterfun com rc lipo batteries html gt 7 Higher Education in Science and Engineering Online Available lt http www nsf gov statistics seind12 pdf c02 pdf gt 8 ROS org Online Available lt http www ros org wiki gt Raspberry Pi purchase Online Available http www newark com jsp search productdetail jsp SKU 43W5302 I amp CMP KNC GPLA I amp mckv pcrid 20115736341 plid o 10 SailBot Online Available 11 UBC SailBot Online Available 12 Vex Robotics Online Available 13 Wyolum Arduino Online Available rojects alamode gt
45. r out of the wind We recommend the Sparkfun LSM303 compass module and the images and descriptions in this guide will assume that you are using this device It comes pretty much assembled but you will need to solder wires to 4 of the leads on the board before using it If you have not done this already check out the Assembling the Sensors guide before continuing 6 Encoder This what you will be using as a wind direction sensor You ll attach a wind vane to the brass rod sticking up out of the encoder which will turn to face the direction of the wind The encoder returns the angular position of the rod from O to 360 degrees Now you might be wondering where is O degrees Where is 360 degrees The rod just keeps turning forever Good point Before using the rod on the boat you will need to calibrate it so that the position it thinks is O degrees is the wind vane pointed towards the bow of the boat and 180 degrees points towards the stern We ll you through that in a bit though 7 5v Servo The two servos on your boat allow the brain to move the rudder and sails to the angles it wants For this guide however you will need a spare 5V servo if you did not receive an extra servo in your kit if you only have the two in the boat then any 5v servo should work If you do not have one lying around you can purchase one online at a website like sparkfun com or at your local radioshack 8 2 Power Blocks There will be 3 sensors and 2
46. rds the waypoint without going into irons or directly downwind go fast outputs where go short outputs not to go into irons where to go at directly downwind waypoint The Raspberry Pi receives sensor data from the alaMode maintain fast sail angle point boat at target chooses a sail angle based tries to use the rudder on the to point the boat where apparent wind The alaMode receives data think py requests from the sensors Sail servo moves sail The Real World Rudder servo moves rudder Why doing testing with Arduino lt gt Computer is useful when you ll be using Raspberry Pi lt gt alaMode in the end We will need to check whether the code on the Raspberry Pi will work with the alaMode eventually but making sure that code on any Arduino to any Computer will work is very valuable The goal is to make sure the code works on you computer where you can see the information very easily Then you can do testing on the RasPi alaMode to make sure it still runs and you re doing less testing with the RasPi alaMode trying to check whether it s doing the right thing Example If the boat is supposed to take the apparent wind and use that to set the sail to an angle that you want it can be hard to test that with everything plugged into the Raspberry Pi If you run the code and the sail doesn t do what you expect there are a number of places problems can be happening in a sensor in the code or in t
47. red for the robotic sailboat The SD card must be formatted flashed and written by an external device The file for the boat s Raspberry Pi is provided electronically so students can flash an SD card following the in cluded instructions The Pi behaves like a regular computer One can plug in a monitor keyboard mouse and ethernet cable and treat it as a desktop or install it in a boat and communicate over wifi by opening an SSH Secure SHell to communicate between two devices on the same network Accessories that use 3 3V logic and a USB cable that allow the user to directly plug into the Raspberry Pi from a computer eliminating the need for a spare keyboard mouse or monitor setup are available On a side note that cable will only allow you to communicate to the pi via command line and will not give you access to the GUL On the water the thinking takes place on the Pi It receives inputs down from the user high level commands such as waypoints and general be haviors and up from the AlaMode low level sensor data The think code on the Pi interprets all of this information decides how to navigate through the world and sends commands to steer the boat down to the AlaMode which controls the sail and rudder See Figure l for the data flow think tries to choose a heading that goes towards the waypoint without going into irons or directly downwind go fast outputs where go short outputs not to g
48. rking from Windows or Mac section DREW SAYS THIS DID NOT WORK FOR HIM 3 2 Installing ROS Everything ROS related can be found on In addition to ROS resources this site also supports an active ROS community that can be queried for advice Immediately upon visiting the site click Install for instructions sorted by operating system Ubuntu a common Linux system is the most common operating system to use with ROS but there are ROS instructions for Win dows as well as other less commonly used operating systems if you would like to learn your way around ROS before installing Linux Once you have installed ROS a number of tutorials can be found at lt www under the Tutorials link It is recommended that you complete all of these tutorials every time you install ROS on a computer because the beginner tutorials both teach the introductory lessons on ROS and walk through a few settings that must be changed on each computer 3 9 Installing Arduino on Linux At the time of this writing the best instructions for downloading Arduino were found at http blog markloiseau con 2012 05 install arduinc ubuntu Notice that these instructions are for Ubuntu 12 04 If they do not work for you search for Arduino install your specific Linux distribution The instructions on Mark s blog should work when followed to completion in cluding Troubleshooting USB and the grayed out Serial Port instructions at the bottom of
49. s and college students along in mentor and volunteer roles VEX and FIRST are household names a major criterion for success in this market Tactics such as com petitive gameplay restricted resources and opportunities for business and marketing thinking contribute to the popularity of these programs A strong mentorship model pervades the competitions at all levels and leads to ulti mate sustainability and a sense of ownership and pride in the participants so we encourage teams to seek committed mentors early in their establishment The following delineates the set up processes for a basic robotic sailboat to participate in this competition 2 Computing Different computing tasks have different requirements Two main restric tions on the computational hardware for a robotic sailboat are size and in put output I O The AlaMode 2 is designed to interface with the Rasp berry Pi 9 in a complementary manner The Pi handles input commands over Wifi very nicely and the AlaMode has plentiful digital and analog I O We have based our platform on the combination of Raspberry Pi and AlaM ode because of the solid flexible capabilities of these devices and their low cost at the time of this writing approximately 40 for the Raspberry Pi and 50 for the AlaMode 2 1 Raspberry Pi The Raspberry Pi is a small computer well suited for hacker projects It is booted from an SD card containing a Linux operating system image custom tailo
50. s explorer before to find or open a file You use explorer by clicking on pictures of folders to open them which reveals the files and other folders they contain With the console you are doing the same thing but there s no mouse You enter a new directory using the command cd which stands for change directory However when you use cd you need to specify which folder you want to change to So you either memorize the name of every folder on your system take it from me don t try this or you use another popular command Is Is lists all the folders and files in the current directory So go ahead and try this command now Just type Is into the terminal and hit enter You should get something that looks kind of like this roscd olinoboat mainpage dox CMakelists txt mission file csv package xml setup py mission file csv howto txt README md So now you can see all the files and directories contained within the folder catkin src sailbot All the purple words are names of other folders and the white words are files Now that we know the names of all the folders we can explore let s try changing directory usually called cding pronounced ceedeeing Go ahead and type cd launch and hit enter Now the name of your current directory should have gone from catkin ws src sailboatto catkin ws src sailboat Launch What this means is that you are now inside the folder launch which is inside folder sailboat which is inside the f
51. servos aboard your boat all which need to be powered from one battery These little gizmos let you plug many wires into one power port We ll show you how they work in a bit Two should have been included in your kit 9 A working linux operating system If you already have some flavor of linux installed on your computer and would like to use that then just follow the Setting up Linux for Rosbian Development guide However you can also get a pre configured VM which has all the software and settings you need pre loaded from site with our vm If you wish to use the VM on a Windows computer follow the brief instructions in the Setting up Windows to use the linux VM Setting up the hardware 1 Connect everything to the power blocks Plug power and ground from each sensor into the power blocks One power block should have all the ground wires plugged into it and the other should have all the power wires The GPS module pwr gnd The compass pwr gnd The servo Wr j gnd The encoder gnd Power Signal Plug all the wires into their respective power block it doesn t matter which one as long as all the gnds are in one block and all the powers are in another Also plug a loose wire stripped at both ends about as long as your hand into both power blocks pwr wires gnd wires pwr wire which gnd wire which goes to battery goes to the battery pwr gnd 2 Connect the alamode to the raspberry pi
52. sion of linux operates When you run the command ssh pi rosbian you are telling your computer to send everything you type into your console to the console on the pi and then display everything the console on the pi sends back in your console The pi part of the command indicates that you want to login into the raspberry pi as the user named pi a user which we have created and pre configured for you So at this point you can consider the console you have open actually a console for the raspberry pi and every command you type as a command you are sending to the device as the user pi 5 Now run the command roscd sailboat Your terminal should now look like this pi rosbian1 catkin ws src sailbot Before you go any further run the command git pull origin master This updates the sailboat code to make sure it will work for the next few steps Now the main use of a console is to navigate around a computer The beginning of the line next to the blinking cursor indicates where in the computer you are So when you see the line pierosbianl catkin_ws src sailbot The part that is highlighted blue and green is the computer and username So you know that you are logged on as the user pi on the computer rosbian1 every computer running Linux has a name so other computers can talk to it The part that is highlighted pink is the directory you are currently in If you normally use Windows as your operating system you may have used Window
53. t positions by hand and make sure that the angle the code wants to set the sail to are correct correct according to A8 The log messages in maintain fast sail angle py should let you see what the apparent wind angle is This could be useful for debugging if the sail angle that maintain fast sail angle py wants to create is not what you expect think tries to choose a heading that goes towards the waypoint without going into irons or directly downwind go fast outputs where go short outputs not to go inta irons where to go at directly downwind waypoint NT el The Raspberry Pl receives sensor data from the alaMode maintain fast sail angle E peint boat at target chooses a sail angle based j tries to use the midder on th to point the boat where apparent wind The ala amp tode receives data think py requests from the sensors l Sail servo moves sail e Run the check sail control launch file The Real World Rudder servo moves nidder Make sure the suggested sail angle is correctly being turned into sail position Setup Plug the encoder and sail servo into the Arduino A10 Power the Arduino with an adequate power source e ino build and ino upload EncoderRead_RosPub ino onto the Arduino Will start Arduino lt gt computer communication e Will run maintain fast sail angle py which looks at wind encoder data and
54. to topics www ros org wiki ROS Tutorials UnderstandingTopics Io wor with the coge you should Ae 80 ie UN ihe Uu ast B ME 2 intor h anc 1 t ne A7 What are topics Topics are the main way of passing data around in ROS If you ve done been doing the tutorials for ROS www ros org wiki ROS Tutorials you will run into this introduction to topics www ros org wiki ROS Tutorials UnderstandingTopics To work with the code you should really go through the introductory ROS tutorials they are relatively simple and there is a large community with FAQs that can help you over hurdles A8 How you know what the sail position should be As of 04 25 13 the sails were set according to the apparent wind angle That means if the wind appears on the wind sensor to be 45 off the bow the sails will be set to what we thought was an appropriate angle 0 full in and 90 full out In the Boogie maintain _fast_ EGUA ES py yoy can find a ite table that contains gli B lis 10 OI pc oints IT Sa I nd of sail LU 45 ol 50 JU 125 1 80 m ERE PER oot meee for e DO 2l u EU NL EDEN l A9 Looking for Log messages In many places in the Olinoboat code we use the command rospy loginfo stuff we want to user to see When you run roslaunch files from the command line to test various pieces of the system as we ve outlined in this guide you should see error messages like this go short py GP
55. umber from 0 to 1027 that increases as you spin the encoder then jumps back to O when you cross 1027 In general if any sensors aren t working it is a good idea to 1 Double check the wiring making sure everything is connected properly and there are no shorts or other problems in the system 2 Usea multimeter to measure the voltage being supplied to the sensors and make sure it is correct think tries to choose a heading that goes towards the waypoint without going into irons or directhy downwind xs ale iJ N go short outputs where to go at waypoint go fast outputs where not to go inta irons directly downwind The Raspberry Pl receives sensor data from the alaMode maintain fast sail angle E 4 chooses a sail angle based point boat at target trees to use the rudder on the to point the boat where apparent wind The ala amp ode receives data think py requests c from the sensors Sail servo moves sail The Real World e Run the check sensor data launch file L a ipe na a Rudder sero moves rudder Making sure the sensor values are being reported accurately to the computer from the Arduino Setup Plug all sensors into the Arduino Power the Arduino with an adequate power source ino build and ino upload PubSub ino onto Arduino if it s not there Will start Arduino lt gt c
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