Absolute position measurement system for mobile robot based on incident angle detection of infrared light

To measure an absolute position of a mobile robot by external observation, many methods using vision system have been proposed. In these methods, a camera is mounted on a ceiling, etc., and a robot is detected by analyzing captured images from the camera. However, to construct distributed sensing system which is flexible for various environments, it becomes important to develop simpler observation device. In this paper, we propose new position measurement system for a mobile robot based on an incident angle detection of infrared light. Infrared light sources are mounted on a robot as markers. An observation device mounted on a ceiling measures only incident angles of infrared light from markers and calculates positions of the robot. After a procedure of geometrical calculation concerned with a position and an orientation of a robot based on measured incident angles, implementations of devices to transmit and receive infrared light are described. Finally, a performance of proposed method is shown through experiments concerned with position and orientation measurements.