3D Indoor Positioning of UAVs with Spread Spectrum Ultrasound and Time-of-Flight Cameras

José A Paredes; Fernando J Álvarez; Teodoro Aguilera; José M Villadangos

doi:10.3390/s18010089

3D Indoor Positioning of UAVs with Spread Spectrum Ultrasound and Time-of-Flight Cameras

Sensors (Basel). 2017 Dec 30;18(1):89. doi: 10.3390/s18010089.

Authors

José A Paredes¹, Fernando J Álvarez², Teodoro Aguilera³, José M Villadangos⁴

Affiliations

¹ Sensory System Research Group, University of Extremadura, 06006 Badajoz, Spain. japaredesm@unex.es.
² Sensory System Research Group, University of Extremadura, 06006 Badajoz, Spain. fafranco@unex.es.
³ Sensory System Research Group, University of Extremadura, 06006 Badajoz, Spain. teoaguibe@unex.es.
⁴ Department of Electronics, University of Alcalá, Alcalá de Henares, 28805 Madrid, Spain. jm.villadangos@uah.es.

Abstract

This work proposes the use of a hybrid acoustic and optical indoor positioning system for the accurate 3D positioning of Unmanned Aerial Vehicles (UAVs). The acoustic module of this system is based on a Time-Code Division Multiple Access (T-CDMA) scheme, where the sequential emission of five spread spectrum ultrasonic codes is performed to compute the horizontal vehicle position following a 2D multilateration procedure. The optical module is based on a Time-Of-Flight (TOF) camera that provides an initial estimation for the vehicle height. A recursive algorithm programmed on an external computer is then proposed to refine the estimated position. Experimental results show that the proposed system can increase the accuracy of a solely acoustic system by 70-80% in terms of positioning mean square error.

Keywords: acoustic positioning system (APS); time-code division multiple access (T-CDMA); unmanned aerial vehicles (UAV).