Ultra-Wideband Smart Wheelchair Pose Estimation Using Interval Analysis

Abstract

In this paper, we introduce a reliable positioning method for a smart wheelchair by using ultra-wideband (UWB) technology.  This method provides confidence domains of the pose by assuming bounded measurement errors and proprioceptive information, without any assumptions of independence. Exploiting interval analysis and constraint propagation techniques, we characterize the sets of all feasible poses that are consistent with the measurements. Our method has been validated through experiments with a smart power wheelchair equipped with UWB sensors in realistic conditions. The results demonstrate that our approach consistently provides guaranteed uncertainty domains with 100% integrity across the tested dataset, even when faced with inconsistent measurements. In addition, we compare our interval-based method with M-estimator approaches, and show that while achieving slightly worse positioning accuracy, our method offers superior consistency.