NavBot 3

Navigation Robot Model 2

Updated 8/29/13


 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!
 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.