New approach cracks indoor GPS problem that has stymied navigation tech
Researchers have demonstrated a more reliable method for tracking objects inside buildings using ultra-wideband signals, a problem that has long limited indoor positioning systems. The advance could unlock new applications in warehousing, robotics, and augmented reality—markets where centimeter-level accuracy indoors remains a competitive advantage.
Originaltitel: Experimental Study of Indoor Tracking Using UWB Measurements and Particle Filtering
<p>Target tracking with ultra-wideband (UWB) signals in indoor environments is a challenging problem due to the presence of multipath and non-line-of-sight conditions (NLOS). A solution to this problem is to use particle filtering (PF), which is able to handle both nonlinear models and non-Gaussian uncertainties that typically appear in the presence of NLOS. In this paper, we compare four different PF variants, that differ in terms of how NLOS measurements are handled. According to our experimental results, based on the measurements from a basement tunnel, multiple features from the UWB impulse response should be used, and the ranging likelihood function should make use of both LOS and NLOS measurements. Standard time-of-arrival (TOA) based methods, even with NLOS rejection, are not good enough. Instead we advocate TOA-based algorithms that can actively mitigate errors due to NLOS.</p>