This robot will charge by
      sunlight, with a solar panel mounted at an angle on its rear.
      Merely setting the robot in the sun when off will keep the battery
      charged and ready. The goal of this robot is to autonomously
      navigate from one end of the house to the other, without using
      beacons or following lines. It will use local landmarks for navigation
      and start and end within an inch of the disired goal locations.
      This goal was accomplished in August of 2013 and after several
      years of work on this robot, the final report can be issued!
CLICK ON THUMBNAILS FOR A 1024 X 768 VIEW
 
 Detailed
      view of the starting configuration of the NavBot 3. A Devantech
      digital compass (now discontinued) is in the acrylic dome at
      the top, mounted on a wooden mast about 12 inches up. The same
      mast supports a large solar cell, which is leaned appropriately
      to capture the sunlight from the east window after sunrise each
      day. The eye lights allow one to see the robots orientation clearly
      in dim lighting situations, and what robot would not have "Terminator"
      style red eyes in the dark? The Devantech Voice synthesizer (also
      now unfortunately just discontinued) allows verbal communication
      of what the robot is currently processing. This is a major help
      in the arena, when you cant see the LCD display on the back of
      the robot most of the time. The wheel encoder is 1024 clicks
      per revolution of one wheel and can be used for precise turns
      or more often moving exact distances on smooth floors. Sonar
      is fixed on the front, but will soon be changed to a movable
      turret for scanning distances. Finally, the bumper array is a
      set of tiny micro switches on the front of the robot for contact
      information.
 
 For
      the first demonstrations, we will incorporate into the robots
      subroutines various methods to not only orient itself accurately
      in a closed arena, but to be able to navigate to a fixed home
      position defined only by X,Y coordinates. The robot must be able
      to find this position from any where in the arena, and park there
      autonomously. This is the first step in the auto-homing process!
      The method used for this first run will be to use the compass
      to orient the robot along the edges of the arena, which happen
      to lie North East at about 48 degrees. Then using the sonar,
      it will identify the walls, determine its current X,Y coordinates
      and plan a movement to the home position, which I am defining
      as X=10 inches, Y= 11 inches from the arenas origin at the lower
      left corner. Sounds easy right? Lets jump in and see the process
      in action...
 

      
Updates and latest
      articles with this robot:

      
August 29th, 2013
      - Final report with movies, images and drawings.

      
February 10, 2013
      - Driving
      to a home position within the Arena



      
Movie
      1
Left: This small movie clip shows the robots
      first task, pointing at the East end of the robot arena. This
      is the first step in navigation, to parallel the walls for X-Y
      computations. The compass on the top of the robot is used here.
      I am showing that no matter how the robot is oriented, it always
      takes the SHORTEST ANGULAR DISTANCE to rotate to the home position.



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