Playing with a Robot: Realization of "Red Light, Green Light" Using a Laser Range Finder

Purpose of this study is to realize a children´s play "Darumasan ga koronda" (red light, green light) by a mobile robot and a human. In this paper, the robot is "it" and the human is the other player. Three functions are needed to make the robot possible to play the game: recognition of a player, "out" judgment and following the player. In this paper, we mainly describe a method of "out" judgment. We put a laser range finder (LRF) on the mobile robot and measure the position of the player. The robot calculates distance between the past and current positions of the human for judging whether the player has moved or not, if the distance is more than the threshold, the robot judges the player "out". The threshold was determined as 40mm and 80mm for two different conditions according to the two experiments of simulating the play. Finally, we conducted an experiment of actually playing the game with the robot, and confirmed that the developed robot could play the game.