Moving Path Estimation Based on Kalman Filter Smoothing of Anchor Node Centroid Points in Commercial Facilities

A simple moving path estimation scheme is proposed using receive signal strength indicators (RSSIs) measured at relatively dense anchor nodes to track the trajectory of a customer walking around in commercial facilities. The anchor nodes are ranked based on RSSI, and then the centroid of the top ranked anchor nodes is calculated as a tentative location. Anchor nodes that are a certain distance away from the centroid are excluded from the candidates for centroid calculation, and then the anchor nodes are re-ranked. The centroid is re-calculated by weighting the RSSI to the re-ranked top anchor node coordinates. The time series of centroid point coordinates is smoothed by fixed lag smoothing of Kalman filter. Simulation results demonstrate that the estimated moving path is smooth and close to the moving path of the target.