Autocalibration algorithm for ultrasonic location systems

As mobile and wearable technology has evolved, an increasingneed for indoor positioning has arisen. In particular,the use of ultrasonics provides a cheap way to fulfil thisneed. However, current ultrasonic location systems have tobe calibrated manually by providing information about theexact positions of the transmitters used. Where systems areto be deployed over a large number of rooms in a building,or in rooms where the transmitters are out of easy reach,manual calibration is particularly time consuming.In this paper, we describe an autocalibration algorithmto compute the position of ultrasonic transmitters using setsof distance readings. This eases the calibration of ultrasoniclocation systems at the initial setup stage, and eliminatesthe possibility of errors in taking manual measurements.We show that an autocalibrated system can produceaccurate location results.