Final Year Project Presentation

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Final Year Project Presentation

• The Design and Implementation
• of an
• Intelligent, Wireless Robot
• By
• Mark Heneghan

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Why a Robot??

• Reasons as to why I choose to do my Final
• Year Project in the field of robotics
• Have been intrigued by robotics always.
• Have a major interest in automotive electronics
  and a robotics project allowed me to gain some
  experience with current research areas.
• A robotics project is useful to the Department,
  as it could be demonstrated to visitors and
  create an interest in the course, due to its
  exciting nature.

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Project Aims

• A project spec was drawn up by consulting with my
  appointed Project Supervisor, Mr. Fergal
  OMalley.
• Here are the basic requirements set out for the
  project
• Design and build a battery powered robot.
• Microprocessor operated.
• Wirelessly controlled via Wifi Internet
  Connection with webpage control interface.
• To implement extra functionality using sensors
  i.e. Line Following and Obstacle Detection.
• Mobile phone control.
• Live Camera Feed.

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Basic Spec Overview
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Research

• The Gumstix Connex 400 mother board was chosen as
  the brains behind the robot.
• Reasons
• 400 MHz Intel PXA255 core processor, allowing
  quick execution of programs.
• Allows Wifi connectivity using the Wifistix
  expansion board.
• Several GPIO for sensors accessed using Breakout
  GS expansion board.
• Pre-installed web server which allows control of
  the robot via a webpage.
• An embedded version of Linux is installed on the
  processor, allowing easy use once a good
  knowledge of the OS is gained.

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Research

• A simple robot kit, the TankBot, was decided on
  as the robot chassis. It contains 2 pre-modified
  servo motors, controlled using Pulse Width
  Modulation.
• In order to program the robot, C was to be used
  initially. However C would have been very complex
  and time consuming. Therefore the higher level
  language Python, was chosen as the language to
  be used.
• Python allows programming of the registers which
  control the GPIO, to be carried out easily. This
  is done by importing the pxaregs kernel module,
  which was pre-installed on the motherboard by the
  Department. A few simple commands is all that is
  required to manipulate the required registers
  only, cutting down on the amount of code to be
  written by approximately a factor of 10 in
  comparison to C.

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Research

• Power was initially to be supplied to the robot
  using 2 power supplies a 5V (later 6V) for the
  Gumstix system and a 6V for motors and other
  hardware.
• However during testing I decided to add a 3rd
  supply, 6V, to supply the demand of all external
  circuitry
• Networking with the robot was made easy by the
  Wifistix which is basically a network card and is
  configured to connect to any desired Wireless LAN
  using the embedded Linux OS.

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Research

• Line Following and Obstacle Detection were
  researched and sensors were chosen to implement
  these functions.
• The Sharp GP2D12 Distance Detector was used for
  Obstacle Detection
• Maplin photo-reflectors were used for Line
  Following.

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Research

• Also research was carried out for extra desired
  add-ons such as Mobile Phone control and Live
  Camera Streaming.
• Mobile Phone control could be achieved using a
  WAP browser or a J2ME application
• The most accessible way to gain live Camera feed
  from the robot was to use an IP camera, one of
  which is being used in a fellow students project
  and may also easily be incorporated into my
  project control webpage.

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Final Design Overview
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Design Implementation

• Gaining experience with using Linux and Gumstix
  was a time consuming part of the project. Once
  basic knowledge of Linux was achieved using the
  Gumstix was not that difficult.
• Initially a USB connection was used to access the
  Gumstix, using USBNet.
• Through USB, Wifi settings were configured to
  connect to the NUIGALWAY wireless network.
• However most programming and testing was carried
  out using a USB connection.

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Design Implementation

• When the Tankbot was constructed, some mechanical
  adjustments were required.
• Motors were tested to find required voltage
  levels and PWM signals to control them.
• Motors needed to be isolated from the Gumstix, in
  order to protect the hardware. Opto-couplers were
  used for this purpose.
• The registers were programmed to configure the 2
  PWM outputs on the Gumstix, in order to implement
  basic control. GPIO16 and GPIO17 are the
  respective GPIO outputs for PWM0 and PWM1.

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Design Implementation
Using Python, programs were written to allow full
control of the robot i.e. Forward, Reverse, Left,
Right and Stop.
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Design Implementation

• Setting up the web-server was relatively simple.
  A simple web page was designed and stored in the
  /var/www folder of the Gumstix, which is the home
  folder of the Boa web-server.
• This site contains links, which execute programs
  to allow full control of the robot using a web
  browser.
• CGI programming is used to execute a program from
  the web. To convert the existing python files to
  CGI, a basic content-type determination is
  placed in the code, which tells the browser how
  to handle any text printed in the program. When
  the program is executed, the browser outputs any
  text printed in the CGI files as HTML.

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Design Implementation
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Design Implementation

• In implementing Obstacle Detection, an ADC was
  used in order to convert the output of the
  Distance Detector into a digital number, which
  may be read by the Gumstix.
• The 3 most significant bits are read from the
  8-bit output ADC. This is to allow the desired
  sensitivity of the Sensor.
• Using a python program the 3 outputs are
  constantly polled and ANDed together. If the
  output is high then an obstacle is within 10
  15 cm. The robot is programmed to reverse a
  certain distance and then turn right and continue
  with forward motion.

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Design Implementation
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Design Implementation

• In implementing line following, a circuit was
  constructed consisting of 3 photo-reflectors.
  Each sensor has an output which is read by the
  Gumstix.
• The 3 outputs are polled using a python program.
  A sensor outputs a high when over black and a
  low when over white.
• The program interprets the GPIO and makes a
  decision as to the motion of the robot.

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Design Implementation
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Design Implementation

• In creating CGI files to execute line following
  and obstacle detection, problems were encountered
  with python as regards internal memory
  allocation.
• Shell programming was used to solve the problem.
• Shell programming, executes Linux shell commands
  in the form of a program, and allow your Linux OS
  to carry out a set of instructions all at once.

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Power Consumption

• A major design issue with the robot is the power
  consumption of the Gumstix system.
• It is powered by a 6V supply, which is obtained
  using a 7806 6V Regulator with 2 x PP3 (9V)
  batteries.
• With all 3 boards connected the system consumes
  about 1.2W at 6V.
• The batteries tend to drain very fast. This is
  also due to the power consumed by the Regulator
  itself.
• Max use time of 2 PP3 Energizer Ultra batteries
  is approximately 2 hours, which proved costly
  when testing the robot.

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Results

• Currently the Project has produced a reliable
  robot which may be fully controlled using any web
  browser.
• It may also operate in Obstacle Detect mode and
  Line Following mode, also executable from the
  web.
• The robot may also be controlled using a WAP
  browser on a mobile phone. This may be only
  simulated using Openwave Phone Simulator, due to
  the IP address of the Wifistix not being
  available outside the NUIGALWAY network. This is
  Computer Services policy.
• It is possible to stream live video, using a
  fellow classmates project, which incorporates
  live streaming from an IP camera based in the
  Lab.
• Unfortunately control using a J2ME application
  was not achieved.

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Results
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Results

• The Gumstix system, was a good choice in hardware
  for this project, although it is not without its
  faults.
• One fault is that it does not securely connect
  together, and all boards are vulnerable to being
  separated easily and hence causing them to short
  and blow.
• However it is a very powerful piece of hardware,
  which has ease of use once minimal experience is
  gained.

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Conclusion

• Overall the project was very beneficial to my
  Degree, as I gained experience in areas which are
  generally not part of the curriculum.
• Also I hope that this project may enhance my
  chances of working in the field of automotive
  electronics, due having gained knowledge in some
  fields which are currently being used or
  researched.
• I also think that this project may be a good
  sample project which can be demonstrated to
  visitors, which may increase interest in
  Electronic Engineering.

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Thank You

• Thanks to my supervisor, Mr. Fergal OMalley for
  his guidance throughout the project.
• Thanks to Mr. Liam Kilmartin for assessing my
  progress in this project.
• Also thanks to the Martin, Myles and Shaun and
  also to Frank Callaly for their assistance with
  any issues encountered during the project.

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Questions???