An Experimental Analysis of the Effect of Reflections on the Performance of Visible Light Positioning Systems in Warehouses

In this paper, an experimental evaluation of the effect of multipath reflections on two 3D positioning algorithms is experimentally compared. The VLP algorithms use the received signal strength (RSS) for estimating the receiver‘s 3D position without prior knowledge of its height. An experimental overall median accuracy of 10.5 cm was achieved in a 4 × 4 × 4.1 m3 test area. The effect of multipath reflections was recreated using a storage shelf rack that is similar to the ones used in warehouses and was placed 26 cm away from the path. The results demonstrate the degrading effect of reflections on two and three-dimensional positioning systems. The reflection‘s effect was especially severe due to reflections from a metal beam. The achieved median errors using the two different algorithms were 7.5 and 6.6 cm before the addition of a shelf rack, and they increased to 11.7 and 12 cm after the shelf rack was added. Multipath reflections increased the median positioning errors by 112% in 2D systems and by 69% for 3D systems. The paper demonstrates the degrading effect of multipath reflections on VLP systems and highlights the need to take it into consideration when evaluating VLP systems.