Patent ID: 11262459

Abstract:
A position estimation unit (2) comprising a first transceiver device (3) and a processing unit (10) that is arranged to repeatedly calculate time-of-flight (TOF) for radio signals (x1, x2, x3, x4, x5, x6) sent pair-wise between two transceivers among the first transceiver device (3) and at least two other transceiver devices (7, 8, 9); calculate possible positions for the transceiver devices (3, 7, 8, 9), which results in possible positions for each transceiver device (3, 7, 8, 9); and perform Multidimensional scaling (MDS) calculation in order to obtain relative positions of the transceiver devices (3, 7, 8, 9) in a present coordinate system. After two initial MDS calculations, between every two consecutive MDS calculations, the processing unit (10) is arranged to repeatedly perform a processing procedure comprising translation, scaling and rotation of present coordinate system such that a corrected present coordinate system is acquired. The processing procedure is arranged to determine the corrected present coordinate system such that a smallest change for the relative positions of the transceiver devices (3, 7, 8, 9) between the consecutive MDS calculations is obtained.