Creating a Lego Mindstorm Navigation Robot :: Robotics

Includes Source Code Lego Navigation System Abstract My project was to create a robot out of a Lego Mindstorms construction set that was capable of â€Å"knowing† where it was. The robot would head out on a random path, remember and update its location, and return to its origin on a straight line. The challenge of this project was not so much a matter of constructing the robot, but of creating a working program in the week and a half time limit. The project goal was met on the last day, thus showing that a Lego navigation system is possible. Background A war zone is a dangerous place, especially for the infantry. Any advantage, technological or otherwise is welcome, and any technology that spares soldiers’ lives is invaluable. Recently, one such technology has made its way to the battlefield; remote controlled robots. These robots can take real-time video, maneuver inside and out, and move hazardous materials out of the way of troops. Two of the leading manufacturer’s of these robots are iRobot and the US Marine Corps. IRobots’ PackBot EOD uses a camera/grabber, multiple sensors, and a unique tread system capable of climbing stairs in order to execute the majority of its tasks. It also has GPS. The US Marine Corps’ Dragon Runner is a rugged, four-wheeled machine with a camera and other sensors safely encased in the body. The Dragon Runner weighs roughly 16 pounds, while the PackBot is just over twice that much weight. While these robots are a great help in a war zone, the navigation system could be improved. If the robot could navigate by itself, the soldiers that previously had to operate the robot would be free to do more important tasks. By implementing a Cartesian coordinate system, I believe that these robots be programmed with a simple self-navigation system. Procedure The physical design of NavBot is very simple. It follows the basic design of TankBot, as described in David Baum’s Definitive Guide to Lego Mindstorms. I chose this design as the basis of my robot due to its simplicity and ease of construction. While it follows the basic TankBot design, it has its variations, because I didn’t want to hunt down all of the â€Å"required† pieces. When I first built the body and tested it, I found that the robot tended to drift to the right. This was easily fixed by changing the power level of the left motor from 7 (highest) to 4. Aside from a few decorations (wings, camel head, smiley face), the physical aspect of NavBot was complete. The more important, as well as complicated, problem was how to program