L.O.S.T Positioning : Line Of Sight Technologies Positioning ofRoboRally Robots

Abstract: RoboRally is a board game where the goal is to drive a smallrobot from a start position to a goal across a dynamic boardwith different types of obstacles. The robots in this gamearen’t real robots, they are small plastic figures which aremoved by hand during the game. Our vision is to researcha solution for implementing the game with real robots. Inorder to do this, precise positioning is key. The purposeof this project was therefore to create a local positioningsystem that allows a robot to find its position in a definedspace and change it on a user command with good precision.The built positioning system is based on the time offlight technique using infrared light and ultrasound. Thesystem uses two transmitters and one receiver to calculatetwo planar distances which can be converted to a coordinatewithin the board.To assess the system performance in a RoboRally applicationa small robot was built and multiple tests conducted.The first result was that a one-dimensional distancecalculation using the time of flight technique achieveda mean error of 3,2 mm for distances shorter than 1 m. Thenext result was that the positioning system achieved a 90x 70 cm rectangle field of view with an accuracy between1 and 6 cm within this area. The last result was that therobot was able to move a specified distance with a precisionof ± 1 mm and then verify its position successfully at a rateof 97 %.The final conclusion of the project is that the positioningsystem is accurate enough for a RoboRally applicationbut needs improvements on its field of view.