Indoor navigation using distributed ultrasonic beacons

This paper presents a novel multilateration based sensor grid, using 40 KHz ultrasonic transducers for indoor positioning. Based on time-of-flight of incoming ultrasonic signals, position of autonomous vehicle is calculated. This allows for conducting silent or covert operations. Multilateration theory and algorithm are first described. Laboratory experiments were performed using an array of transmitters set up on the ceiling and the sensor system was tested for position accuracy. Experimental results show the prototype system to have a 1- sigma position error of about 16 cm. This research work lays down foundations for future development of ultrasonic navigation sensors for micro Unmanned Aerial Vehicles (UAVs) in indoor environments.