A new home robot positioning system (HRPS) using IR switched multi ultrasonic sensors

We propose a very fast measuring system for the location of a mobile robot in an indoor environment. The proposed localization method utilizes ultrasonic and infrared signals simultaneously. The transmitter, which is mounted on the mobile robot, transmits both ultrasonic and infrared signals at the same time. The receivers, which are located at fixed points in the ceiling of the room use the received infrared signal as a trigger to measure the time of flight of the ultrasonic signal. The location of the robot is computed by measuring its distance from three receivers. The heading of the robot is computed by measuring its position in two successive points while the robot moves from one point to the other. The performance and validity of this system are evaluated using one transmitter and six receivers located in a 6 m/spl times/4 m room. The positioning error is less than 5 cm.