Creating a Lego Mindstorm Navigation Robot :: Robotics

Includes Source CodeLego Navigation SystemAbstractMy confinement was to create a automaton out of a Lego Mindstorms construction rank thatwas fit of knowing where it was. The automaton would head out on a random path,remember and update its location, and return to its origin on a straight line. The challengeof this project was not so much a matter of constructing the robot, but of creating aworking course of instruction in the workweek and a half time limit. The project goal was met on the go awayday, thus showing that a Lego navigation system is possible.BackgroundA war zone is a dangerous place, especially for the infantry. Any advantage, expert or otherwise is welcome, and any technology that spares soldierslives is invaluable. Recently, one such technology has made its way to thebattlefield remote controlled robots. These robots can take real-time video,maneuver inside and out, and move hazardous materials out of the way oftroops. two of the leading manufacturers of th ese robots are iRobot and the USMarine Corps. IRobots PackBot EOD uses a camera/grabber, multiple sensors,and a unique tread system capable of climbing stairs in order to execute themajority of its tasks. It besides has GPS. The US Marine Corps Dragon Runner is arugged, four-wheeled machine with a camera and other sensors safely encasedin the body. The Dragon Runner weighs roughly 16 pounds, while the PackBot isjust all over twice that much weight. While these robots are a great abet in a warzone, the navigation system could be improved. If the robot could navigate byitself, the soldiers that previously had to operate the robot would be impeccant to domore important tasks. By implementing a Cartesian devise system, I believethat these robots be programmed with a simple self-navigation system.ProcedureThe physical design of NavBot is very simple. It follows the basic design ofTankBot, as described in David Baums Definitive Guide to Lego Mindstorms. Ichose this design as the reason of my robot due to its simplicity and ease ofconstruction. While it follows the basic TankBot design, it has its variations,because I didnt want to hunt down all of the required pieces. When I first builtthe body and tested it, I found that the robot tended to drift to the right. Thiswas easily fixed by changing the power take of the left motor from 7 (highest) to4. Aside from a few decorations (wings, camel head, smiley face), the physicalaspect of NavBot was complete.The more important, as well as complicated, problem was how to program