Experimental study of trilateration algorithms for ultrasound-based positioning system on QNX RTOS

摘要

This paper presents an indoor localization system to determine the position of a target in 3D environment using RF and Ultrasound. Distances from the target to reference nodes are calculated using Time Difference of Arrival (TDoA) principle. Then trilateration algorithms, namely Linear Least Squares, Nonlinear Least Squares, Closed-Form Position and Cayley-Menger Determinants, are applied to determine the target position. All software programs, except the one on pre-processing board, are developed based on QNX Neutrino RTOS which has many advantages such as micro-kernel architecture, POSIX-certified. QNX is also applied popularly in modern embedded systems. A hardware system is built and experiments have been carried out to verify the system operation and compare the accuracy between the positioning algorithms.