# US 2019/0170891 A1 · Capacitive Sensor and Method for Sensing Changes in a Space > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0170891 A1 - Document ID: US20190170891A1 - Status: Published application - Kind: A1 - Application number: 16/098,375 - Filed: 2017-05-03 - Published: 2019-06-06 - Earliest claimed: 2016-05-03 - Assignees: Sisvel Technology S.R.L. - Applicants: Sisvel Technology S.R.L. - Inventors: Mihai Teodor Lazarescu; Akhmareh Alireza Ramezani; Luciano Lavagno - Web page: https://patentgrep.com/patent/US20190170891A1 ## CPC - G01V 3/08: operating with magnetic or electric fields produced or modified by objects or geological structures or by detecting devices (with electromagnetic waves G01V3/12) - G01V 3/088: {operating with electric fields (G01V3/082 takes precedence)} - G08B 13/26: by proximity of an intruder causing variation in capacitance or inductance of a circuit - G08B 21/22: responsive to presence or absence of persons - A61B 5/1113: {Local tracking of patients, e.g. in a hospital or private home} - G01V: GEOPHYSICS; GRAVITATIONAL MEASUREMENTS; DETECTING MASSES OR OBJECTS; TAGS (means for indicating the location of accidentally buried, e.g. snow-buried, persons A63B29/02) - G08B: SIGNALLING SYSTEMS, e.g. PERSONAL CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) ## Abstract A system for localizing an object of interest in a monitored space includes a plurality of capacitive sensors for sensing changes in the status of a space, adapted to electrically interact in a contactless way with a ground surface so as to provide a capacitance varying on the basis of such changes, and adapted to detect at least a time evolution of the capacitance and to produce a capacitance-depending signal, a filtering unit configured for reducing the noise level in the time evolution of such capacitance by filtering the capacitance-depending signal provided by the capacitive sensors, so that corresponding filtered signals are produced, and a central device in signal communication with the capacitive sensors. The central device is configured for acquiring the filtered signals of each capacitive sensor, and for determining the position of the object of interest inside the space by inferring at least a distance of the object on the basis of the filtered signals acquired from at least one of the sensors detecting the object, and by combining the at least a distance with positional data defining the positions of the plurality of capacitive sensors in the monitored space. ## Claims ### Claim 1 A system for localizing at least one object of interest in a monitored space, comprising a plurality of capacitive sensors for sensing changes in the status of a space, adapted to electrically interact in a contactless way with a ground surface so that each of said capacitive sensors is adapted to provide a capacitance varying on the basis of said changes, to detect at least a time evolution of said capacitance, and to produce at least a capacitance-depending signal on the basis of said at least a time evolution of said capacitance, a filtering unit configured for reducing the noise level in said capacitance-depending signals by filtering them, so that filtered signals are produced, and a central device in signal communication with said capacitive sensors, configured for acquiring the filtered signals of each capacitive sensor, and determining a position of said object of interest inside said space by inferring at least a distance of said object on the basis of the filtered signals acquired from the sensors that detected said object, and by combining said at least a distance with positional data defining the positions of said plurality of capacitive sensors in the monitored space. ### Claim 2 (depends on 1) The system according to claim 1, wherein said central device is configured to work in an operative mode and in a training mode, and wherein during said training mode the central device is configured to acquire training data generated by associating at least a predetermined position of said object in said space with the filtered signals acquired by said sensors when said object is in said predetermined position. ### Claim 3 (depends on 2) The system according to claim 2, wherein, during said operative mode, the central device is configured for determining, on the basis of said training data, the position of said object by selecting the position of the training data associated to the filtered signals that better matches the filtered signals acquired in the training mode. ### Claim 4 (depends on 3) The system according to claim 3, wherein the selection of the position is performed by means of a localization technique. ### Claim 5 (depends on 1) The system according to claim 1, wherein said filtering unit comprises a plurality of filters each associated with one of said capacitive sensors and with said central device, said filters being configured for reducing the noise level present in one of the capacitance-depending signals provided by said capacitive sensors. ### Claim 6 (depends on 1) The system according to claim 1, wherein said filtering unit is associated with a plurality of capacitive sensors and with said central device, said filtering unit being configured for reducing the noise level present in the capacitance-depending signals provided by said plurality of said capacitive sensors. ### Claim 7 (depends on 1) The system according to claim 1, wherein the transfer function of the filtering unit can be varied by means of a switching command, and wherein said central device is configured for generating said switching command. ### Claim 8 (depends on 1) The system according to claim 1, wherein the central device is configured for acquiring said filtered signals and determining the position of said object of interest cyclically with a time period, and said central device is configured to monitor the time evolution of said filtered signals in order to either trace the electrical state of the object of interest when it is detected to be static and/or to trace the path of said object when it is detected to be in motion. ### Claim 9 (depends on 8) The system according to claim 8, wherein said time period can be varied. ### Claim 10 (depends on 1) The system according to claim 1, wherein the central device is further configured to detect the appearance in a monitored space of a new object causing a capacitance variation detected by at least one of said capacitive sensors and to monitor the position and/or the electrical state of said new object that becomes the object of interest. ### Claim 11 (depends on 1) The system according to claim 1, wherein the central device is further configured to detect whether at least one of said filtered signals is comprised either in a first set or in a second set, wherein said first set contains filtered signals that are considered by the central device as a normal, non-alerted status of said monitored space, and said second set contains filtered signals that are considered by the central device as an abnormal, alerted status of said monitored space, and wherein the central device is also configured for signalling about detecting a normal or an abnormal status of said space. ### Claim 12 A central device for being part of a system for localizing at least one object of interest in a monitored space, wherein said central device can be in signal communication with a plurality of capacitive sensors adapted for sensing changes in the status of a space by electrically interacting in a contactless way with a ground surface so that each of said capacitive sensors is adapted to provide a capacitance varying on the basis of said changes, to detect at least a time evolution of said capacitance, and to produce at least a capacitance-depending signal, wherein said central device comprises a filtering unit configured for reducing the noise level in said capacitance-depending signals by filtering them, so that corresponding filtered signals are produced, and wherein said central device is configured for: acquiring the filtered signals of each capacitive sensor, and determining a position of said object of interest inside said space by inferring at least a distance of said object on the basis of the filtered signals acquired from the sensor that detected said object, and by combining said at least a distance with positional data defining the positions of said plurality of capacitive sensors in the monitored space. ### Claim 13 A central device for being part of a system for localizing at least one object of interest in a monitored space, wherein said central device can be in signal communication with a filtering unit configured for reducing the noise level in capacitance-depending signals by filtering at least a capacitance-depending signal provided by said capacitive sensors, so that corresponding filtered signals are produced, wherein said capacitive sensors are adapted for sensing changes in the status of a space by electrically interacting in a contactless way with a ground surface so as to provide a capacitance varying on the basis of said changes, and adapted to detect at least a time evolution of said capacitance and to produce a capacitance-depending signal, said central device being configured for: acquiring the filtered signals of each capacitive sensor, and determining a position of said object of interest inside said space by inferring at least a distance of said object on the basis of the filtered signals acquired from the sensor that detected said object, and by combining said at least a distance with positional data defining the positions of said plurality of capacitive sensors in the monitored space. ### Claim 14 A method for localizing at least an object of interest in a monitored space, comprising: a detection phase, wherein at least a capacitance-depending signal is detected by means of a detecting unit in communication with a plurality of sensors, wherein said at least one capacitance-depending signal is produced by a time evolution of at least a capacitance, wherein said capacitance varies on the basis of changes in said monitored space, a filtering phase, wherein filtered signals are produced by filtering said at least one capacitance-depending signal by means of filtering unit, so that the noise level in said at least one capacitance-depending signals is reduced, an acquisition phase, wherein said filtered signals are acquired by a central device, and a position determination phase, wherein a position of said object of interest inside said space is determined, by means of said central device, by inferring at least a distance of said object on the basis of the filtered signals acquired from at least one of the sensors detecting said object, and by combining said at least a distance with positional data defining the positions of said plurality of capacitive sensors in the monitored space. ### Claim 15 (depends on 14) A computer program product which can be loaded into the memory of a digital processing device, and which comprises portions of software code for executing the method according to claim 14. ### Claim 16 (depends on 4) The system according to claim 4, wherein the localization technique comprises a K-nearest neighbors or a naïve Bayes.