Localization of a person moving with an unknown character of motion

Abstract

In the last decade, it has been shown that short-range ultrawideband (UWB) sensors can provide promising solutions to the issue of people localization in many interesting applications. The applicability of particular localization methods utilizing this wireless technology depends on the form of the motion of the monitored person. Therefore, great effort was initially taken to localize people who always carry out the same type of movement, i.e. to localize either moving or only static persons. In real life, people do not move always by the same form of the motion, but the character of their movement is normally time-variable. Moreover, a person-monitoring system has usually no a priori information about the movement status of the person to be monitored. The issue of localization of persons moving both by an unknown and changing character of motion has not been satisfactorily addressed. Motivated by these findings, we will introduce a new concept of UWB sensor signal processing focused on localization of a person moving with an unknown and time-variable character of motion. This concept is based on the decomposition of possible motion activities of persons into a finite set of basic forms of movement defining the so-called types of persons, while a specific signal processing procedure is proposed. The corresponding form of a person's movement is first identified and then the person is detected and localized. The performance properties of this concept will be illustrated by its application for through-the-wall localization of a person moving with short and long stops.

A Novel Signal Processing Scheme for Static Person Localization Using M-Sequence UWB Radars

“…In the case of people monitoring by using an M-sequence UWB radar, raw radar signals (or radar scans) are represented by a set of impulse responses of the environment, through which the electromagnetic waves emitted by the radar are propagated from transmitting radar antenna (Tx) to receiving radar antenna (Rx). The radar scans thus defined can be modeled by the expression h (t, τ ) = f (s (t, τ ) , n (t, τ ) , c (t, τ ) , i (t, τ ) , j (t, τ )) , (1) where t, τ , s (t, τ ), n (t, τ ), c (t, τ ), i (t, τ ) and j (t, τ ) denote the propagation time, observation time, radar echos, noise generated by radar circuitry, clutter, interference, and jamming, respectively [4]. The operator f (•) represents the input-output model of an analog front-end of a radar receiving channel.…”

“…Because the EN CR for SP detection is usually very low, it should be improved before the implementation of any methods of SP detection. As a result, the process of the SP detection is usually decomposed at least into three stages, which include noise and clutter suppression, an estimation of P (t j , τ ), and finally the detection itself [4].…”

“…We have not addressed the issue of person B tracking if he is in the role of MP (B and D phases) because the solution of this issue is beyond this paper. Some starting points for solving the mentioned problem are indicated e.g., in [4].…”

“…The respiration motions are usually the only visible form of SP movement. A proper fusion of the methods developed for MP and SP detection and localization allows monitoring of persons moving with an unknown time-variable character of motion (MP-SP) [4]. Such functionality is usually requested by any localization system.…”

“…Such functionality is usually requested by any localization system. A survey of the methods of MP localization presented e.g., in [4] and [5] have shown that, with respect to MP-SP monitoring, the developed approaches to MP localization can be considered well handled. However, the state-of-the-art in the field of SP localization has indicated that currently available methods have not been sufficiently adapted for their exploitation for MP-SP monitoring.…”