Asset tracking system

Abstract

The invention provides an asset tracking system (100) for tracking a target tag (10) in a space (500), wherein the target tag (10) is configured to emit a target beacon signal, wherein the asset tracking system (100) comprises a plurality of listener nodes (110) arranged in the space (500) and configured to detect the target beacon signal, wherein the asset tracking system (100) comprises a control system (300), wherein the control system (300) has access to (i) listener position data and (ii) map data, wherein in an operational mode: the control system (300) determines a presence of an object (200), wherein an object tag (210) is associated with the object (200), and wherein the object tag (210) is configured to emit an object beacon signal, wherein the plurality of listener nodes (110) is configured to detect the object beacon signal and provide a related object signal to the control system (300); the control system (300) determines, for each listener node (110), a set of confidence regions (230) based on the related object signal, the listener position data, and the map data; the plurality of listener nodes (110) detects the target beacon signal and provides a related target signal to the control system (300); and, the control system (300) determines a target tag position of the target tag (10) based on the related target signal, the listener position data, the map data, and the set of confidence regions (230) of the plurality of listener nodes (110).

Description

TECHNICAL FIELD

[0001] The present invention relates to an asset tracking system. The present invention also relates to a method for locating a transmission position of a beacon signal. BACKGROUND

[0002] Asset tracking systems are known in the art. For example, Kim et al. “Accuracy Improvement of Real-Time Location Tracking for Construction Workers” describes a real-time location system using radio frequency identification (RFID). It describes a position tracking error mitigation algorithm and the use of auxiliary tags. US2010 / 158331A1 discloses a tracking system in surgery with tags on surgical instruments. SUMMARY

[0003] An asset tracking system can typically comprise three types of field devices: (mobile) tags, listener nodes (or “anchors”), and gateways. In such a system, a tag can transmit a beacon signal, and a listener node can detect an incoming beacon signal sent by a tag and take a measurement (e.g. a signal strength measurement). The measurement can typically be taken by multiple listener nodes, and the listener nodes can send these results to a gateway from which they can be further processed, e.g. by further forwarding them to a positioning engine on a server or in the cloud.

[0004] The listener nodes can be spatially distributed throughout a space in which a tag is to be tracked to provide good coverage of that space, and the tag can then be located based on signals from multiple listener nodes. For example, a position engine can estimate that a tag is closest to a listener node that recorded the highest signal strength about a beacon signal.

[0005] However, the prior art approach can suffer from individual listener nodes becoming temporarily (or substantially permanently) obstructed, e.g. due to the placement of a (large) object in the space (e.g. in a factory hall or a shopping mall). The object can interfere with the detection of a beacon signal by a listener node. Nevertheless, the listener node can still detect the beacon signal, which can ultimately have a net negative result on the positioning of the tag by the position engine. For example, a tag can be very close to a listener node, but the listener node can detect a relatively weak signal due to the line of sight (LOS) between the listener node and the tag being obstructed. Based on this weak signal, the position engine can estimate that the tag is far away from the listener node.

[0006] It is therefore an aspect of the present application to provide an alternative asset tracking system which preferably further at least partially obviates one or more of the above-mentioned drawbacks. It is an object of the present application to overcome or ameliorate at least one of the disadvantages of the prior art, or to provide a useful alternative.

[0007] The present application is therefore defined by the appended independent claims and corresponding dependent claims.

[0008] Thus, in a first aspect, the present application can provide an asset tracking system for tracking a (mobile) target tag, especially in a space. The asset tracking system can comprise a plurality of listener nodes arranged in the space. The asset tracking system can further comprise a control system. In embodiments, the control system can have access to listener position data, especially listener position data of the plurality of listener nodes. In further embodiments, the control system can have access to map data, especially map data of the space. The asset tracking system can also have an operational mode (or "operate in an operational mode"). The operational mode can comprise one or more of an object detection phase, a confidence region determination phase, a tag detection phase, and a tag localization phase.

[0009] In the object detection phase, the control system can (be configured to) determine a presence of an object (in the space), especially wherein an object tag is associated with the object. The object tag and at least a portion of the total number of the plurality of listener nodes can (be configured to) communicate via object communication signals and provide a related object signal to the control system.

[0010] In the confidence region determination phase, the control system can (be configured to) determine a set of (object-related) detection confidence regions for each listener node based on one or more of the related object signal, the listener position data, and the map data, especially based on the related object signal, the listener position data, and the map data.

[0011] In the tag detection phase, the target tag and at least a portion of the total number of the plurality of listener nodes can (be configured to) communicate via target communication signals and provide a related target signal (also referred to as: "(related) position signal" or "(related) tracking signal") to the control system.

[0012] In the tag localization phase, the control system can (be configured to) determine a target tag position (estimate) of the target tag based on one or more of the related target signal, the listener position data, the map data, and the set of confidence regions of at least a portion of the total number of the plurality of listener nodes, especially based on the related target signal, the listener position data, the map data, and the set of confidence regions.

[0013] In a particular embodiment, the present invention provides an asset tracking system for tracking a target tag in a space, wherein the asset tracking system comprises a plurality of listener nodes arranged in the space, and wherein the asset tracking system comprises a control system, wherein the control system has access to (i) listener position data and (ii) map data, wherein in an operational mode: the control system (is configured to) determine a presence of an object, wherein an object tag is associated with said object, and wherein said object tag and said plurality of listener nodes are configured to communicate via object communication signals and provide a related object signal to said control system; the control system (is configured to) determine a set of confidence regions for each listener node based on the related object signal, the listener position data, and the map data; the target tag and the plurality of listener nodes are configured to communicate via target communication signals and provide a related target signal to the control system; and the control system (is configured to) determine a target tag position of the target tag based on the related target signal, the listener position data, the map data, and the set of confidence regions of the plurality of listener nodes.

[0014] The asset tracking system of the present invention can provide the benefit that the control system takes into account an object (also referred to as an “obstacle”) when determining a target tag position. Thereby, the target tag position can be determined more accurately when an object moves in the space and / or when an object is (temporarily) arranged in the space and thereby interferes with the communication between the listener nodes and the target tag - especially by obstructing the view of the listener nodes and thereby the detection of the target beacon signal by the listener nodes (see below).

[0015] In particular, an object can be tagged with an object tag, thereby allowing the asset tracking system to (directly) track the object. Based on the communication between the object tag and the listener nodes - especially the detection of the object beacon signal by the listener nodes - the control system can (be configured to) estimate a confidence region for each listener node, e.g., the control system can (be configured to) determine that due to the object partially obstructing the communication path - especially the view - of the listener nodes, the listener nodes can have reduced suitability to track the target tag in a first portion of the space (low confidence region), while remaining suitable to communicate - especially detect - the target tag in a second portion of the space (high confidence region). If the object is moved, the asset tracking system can (dynamically) update the confidence region for each listener node, thereby facilitating to maintain an accurate localization in a space with a (large) moving object.

[0016] In particular, the present invention can enable to take into account a (moving) object in the space, wherein the object can interfere with the communication between the target tag and the listener nodes - especially the detection of the target beacon signal by the listener nodes - thereby accurately localizing the target tag in the space.

[0017] Thus, in a first step, the object (or "obstacle") can be automatically located and its dimensions determined by using the same tracking system infrastructure as the asset tracking system. The automatic location and dimensioning can even be performed while the object (e.g. a gantry crane) is in motion. In a second step, the position and dimensions of the obstacle can be used to calculate the blocked line-of-sight area with respect to each listener node in the neighborhood. In a third step, the positioning engine for calculating the position of the target tag can exclude data from listener nodes associated with the blocked area when the target tag is moving towards or has already been in the blocked area.

[0018] In a further embodiment, the target tag can (be configured to) emit a target beacon signal, in particular periodically. In particular, the plurality of listener nodes can be configured to detect the target beacon signal and provide a related target signal to the control system. Thus, the target communication signal can be the target beacon signal.

[0019] In a further embodiment, the object tag can (be configured to) emit an object beacon signal, in particular periodically. In a further embodiment, the object beacon signal can in particular comprise an object identification signal. In a further embodiment, the plurality of listener nodes can be configured to detect the object beacon signal and provide a related object signal to the control system. Thus, the target communication signal can be the target beacon signal.

[0020] Embodiments in which both the target tag and the object tag emit respective beacon signals can be particularly advantageous, as the tags are only active for a short period of time to emit the beacon signal, while the tags can be active for a longer period of time, in particular continuously, if the tags are to detect communications from the listener nodes. Thus, embodiments in which the tags emit beacon signals can be more efficient in terms of battery life of the tags.

[0021] Thus, in particular embodiments, the present application can provide an asset tracking system for tracking a target tag in a space, wherein the target tag periodically emits a target beacon signal, wherein the asset tracking system comprises a plurality of listener nodes arranged in the space and configured to detect the target beacon signal, wherein the asset tracking system comprises a control system, wherein the control system has access to (i) listener location data and (ii) map data, wherein in an operational mode: (a) the control system determines (is configured to determine) a presence of an object, wherein the object tag is associated with the object, and wherein the object tag is configured to emit an object beacon signal, wherein the plurality of listener nodes is configured to detect the object beacon signal and provide a related object signal to the control system; (b) the control system determines (is configured to determine) for each listener node a set of confidence regions based on the related object signal, the listener location data, and the map data; (c) the plurality of listener nodes detects (is configured to detect) the target beacon signal and provides a related target signal to the control system; and (d) the control system determines (is configured to determine) a target tag location of the target tag based on the related target signal, the listener location data, the map data, and the set of confidence regions of the plurality of listener nodes.

[0022] Thus, in embodiments, the tags can emit respective beacon signals, which can be detected (or: “received”) by the listener nodes, and the listener nodes can provide a related signal to the control system, i.e. the target communication signal can be a target beacon signal and the object communication signal can be an object beacon signal. Generally, such embodiments can be preferred (compared to embodiments, in which the listener nodes emit signals, which are detected by the tags) in view of the battery life of the tags.

[0023] In further embodiments, the plurality of listener nodes can (be configured to) emit listener node signals, in particular periodically emit listener node signals. In particular, each listener node of the plurality of listener nodes can emit a (respective) listener node signal. In particular, the target tag can be configured to detect the listener node signals from (at least a portion of) the plurality of listener nodes and provide a related target signal to the control system. Thus, the target communication signal can be a listener node signal.

[0024] In further embodiments, the plurality of listener nodes can (be configured to) emit listener node signals, in particular periodically emit listener node signals. In particular, the target tag can be configured to detect the listener node signals from (at least a portion of) the plurality of listener nodes and provide a related target signal to the control system. Thus, the target communication signal can be a listener node signal.

[0025] Generally, either both the target tag and the object tag can (be configured to) emit a beacon signal, or both can be configured to detect a listener node signal. However, mixed embodiments are also possible.

[0026] For the purpose of explanation, the application will be described in the following (mainly in the context of embodiments), in which both tags are configured to emit a beacon signal. It will be clear to the skilled person that the application is not limited to these embodiments.

[0027] Hence, the application can provide an asset tracking system for tracking a target tag in a space. The term "asset tracking system" can refer to any system configured to track the position and / or movement of one or more target tags within a space, in particular a (defined) space.

[0028] The term "target tag" (also referred to as "tag") can here refer to an item that can be tracked, in particular a uniquely identifiable item, for example by being provided with a target tag identification. The target tag can in particular be connected to (a larger) item that is desired to be tracked, for example attached to the item, or for example worn by a person. For example, the target tag can comprise one or more of a sticker, a badge, a wristband, and a token. Further, the target tag can be configured to emit a wireless signal, for example a radio beacon, or for example a Bluetooth Low Energy beacon.

[0029] Generally, the target tag can be a mobile target tag.

[0030] The term "space" can here refer to any space in which it can be desired to track the location of a target tag. The space can in particular comprise a building (part), for example a shopping center, a factory, or a hospital (part). However, the space can also be located outside. For example, the space can comprise a leisure park or a farm. In embodiments, the term "space" can refer to an office, a shop, a warehouse, a theater, a reception area, a hospital, a nursing home, a hotel, a factory, an airport, a shopping center, a manufacturing plant, a horticulture plant. The term space can refer to an indoor space or an outdoor space, in particular an indoor space. As will be clear to the skilled person, generally, the space is not comprised by the asset tracking system, i.e. the space is not part of the system.

[0031] The object tag and the plurality of listener nodes can be configured to communicate (wirelessly) via object communication signals. In embodiments, the object communication signals can comprise object beacon signals, wherein the object tag is configured to transmit the object beacon signals, and wherein the plurality of listener nodes is configured to detect the object beacon signals. In further embodiments, the object communication signals can comprise listener node signals, wherein the plurality of listener nodes is configured to transmit the listener node signals, and wherein the object tag is configured to detect (or "receive") the listener node signals. In particular, the element receiving the object communication signals, e.g. the plurality of listener nodes in case of object beacon signals, can provide the relevant object signals to the control system.

[0032] The object tag and the plurality of listener nodes can be configured to communicate (wirelessly) via object communication signals. In embodiments, the object communication signals can comprise object beacon signals, wherein the object tag is configured to transmit the object beacon signals, and wherein the plurality of listener nodes is configured to detect the object beacon signals. In further embodiments, the object communication signals can comprise listener node signals, wherein the plurality of listener nodes is configured to transmit the listener node signals, and wherein the object tag is configured to detect (or "receive") the listener node signals. In particular, the element receiving the object communication signals, e.g. the plurality of listener nodes in case of object beacon signals, can provide the relevant object signals to the control system.

[0033] In embodiments, the object tag can be configured to transmit object beacon signals (or: "beacon signals").

[0034] In embodiments, the object tag can be configured to transmit beacon signals periodically. In further embodiments, the object tag can transmit beacon signals according to a regular period, e.g. every 15 minutes. However, in further embodiments, the object tag can transmit object beacon signals according to an irregular period, e.g. a period that varies with the time of day, or whenever an external signal is received, or whenever the object tag is moved. For example, the object tag can comprise a (passive) RFID tag, and can transmit a beacon signal upon reception of a (suitable) radio wave.

[0035] In further embodiments, the object tag can be configured to transmit object beacon signals (substantially) continuously.

[0036] The target beacon signal can comprise any type of signal that can be detected by multiple listener nodes. In embodiments, the beacon signal can for example comprise a wireless communication signal, such as a wireless communication signal selected from the group comprising a Bluetooth signal, a ZigBee (beacon packet) signal, a Wi-Fi (beacon packet) signal, a Li-Fi (beacon packet) signal, an Ultra-Wideband packet signal, and a Thread signal. In embodiments, the target beacon signal can comprise one or more carrier frequencies, in particular multiple carrier frequencies.

[0037] The target beacon signal can in particular comprise a target tag identification code. The target tag identification code can be specific to the target tag and can be particularly suited to uniquely identify the target tag. Thereby, different target tags can be distinguished and different (tagged) items can be (independently) tracked.

[0038] The target beacon signal can further comprise a target beacon signal sequence number. The target beacon signal sequence number can be specific to the target tag for a given time and can be sequentially increased until it reaches a maximum number allowed, after which it wraps back to a minimum number allowed. Thereby, different target beacon signals can be distinguished and different target beacon signals from a target tag can be uniquely identified by e.g. a listener for a short time period in which it is not likely that more than one target beacon signal from a target tag has the same sequence number.

[0039] The asset tracking system can comprise a plurality of listener nodes. In the art, a listener node can also be commonly referred to as a“tag listener”, a“tag locator”, an“anchor node”, a“tag scanner”, a“reference node”, and a“sniffer”. In embodiments, a listener node can be configured to detect (or: to“receive”) a target beacon signal, i.e. a listener node can be able to detect a target beacon signal. A listener node can in particular detect a beacon signal passively. In further embodiments, a listener node can comprise an antenna configured for detecting (or: for“receiving”) a target beacon signal.

[0040] A listener node can in particular be arranged in space, i.e. in a space in which a target tag is to be tracked. It will be clear to the skilled person that a listener node can be arranged at a location that is not typically reached by a target tag, e.g. a target tag can be used to track people in an office building and a listener node can be arranged in the lighting system of the office building.

[0041] Hence, the application also provides a lighting system comprising a plurality of lighting devices, wherein two or more lighting devices, in particular at least 6, such as at least 8, like at least 12, even more particularly at least 20 lighting devices, comprise a respective listener node for use in the asset tracking system described herein. In another aspect, however, the application also provides a lighting system comprising the asset tracking system described herein.

[0042] In embodiments, the plurality of listener nodes can be configured to emit listener node signals (or: "listener signals").

[0043] In embodiments, (at least a part of) the plurality of listener nodes can (be configured to) emit listener node signals periodically. In particular, each of (at least a part of) the plurality of listener nodes can (be configured to) emit (a respective) listener node signal periodically. In further embodiments, the plurality of listener nodes can emit one listener node signal according to a regular period, e.g. every 15 minutes. In yet further embodiments, however, the plurality of listener nodes can emit listener node signals according to an irregular period, e.g. a period that varies with the time of day, or whenever an external signal is received. For example, the plurality of listener nodes can comprise (passive) RFID tags, and can emit listener node signals upon receiving (suitable) radio waves.

[0044] In further embodiments, the plurality of listener nodes can (be configured to) emit listener node signals (substantially) continuously.

[0045] The listener node signals can comprise any type of signal that can be detected by the target tag and / or object tag. In embodiments, the listener node signals may, for example, comprise wireless communication signals, such as selected from the group comprising Bluetooth signals, ZigBee (beacon packet) signals, Wi-Fi (beacon packet) signals, Li-Fi (beacon packet) signals, Ultra- Wideband packet signals, and Thread signals. In embodiments, the listener node signals can comprise one or more carrier frequencies, in particular a plurality of carrier frequencies.

[0046] For each listener node, the (respective) listener node signal can in particular comprise a listener node identification code. The listener node identification code can be specific to that listener node, and can in particular be suitable to uniquely identify that listener node. Thereby, different listener nodes can be distinguished.

[0047] The listener node signal can further comprise a listener node signal sequence number. The listener node signal sequence number can be specific to a plurality of listener nodes for a given time and can be sequentially increased until it reaches a maximum number allowed, after which it loops back to a minimum number allowed. Thereby, different listener node signals can be distinguished and different listener node signals from a plurality of listener nodes can be uniquely identified by e.g. the target tag and / or the object tag within a short time period, within which it is known that it is not possible for the plurality of listener nodes to emit listener node signals with the same listener node signal sequence number.

[0048] In embodiments, the target tag can be configured to detect the listener node signal.

[0049] In further embodiments, the object tag can be configured to detect the listener node signal.

[0050] In embodiments, the asset tracking system can further comprise a control system. The control system can in particular be configured to control the asset tracking system, in particular the plurality of listener nodes.

[0051] In embodiments, the control system can have access to listener position data (also referred to as “position data”), in particular a plurality of listener position data of the plurality of listener nodes. The listener position data can in particular comprise data about a position of (each of) the plurality of listener nodes in the space, e.g. data about a room of (each of) the plurality of listener nodes, and / or e.g. coordinates of (each of) the plurality of listener nodes.

[0052] In further embodiments, the control system can have access to map data, in particular map data of the space. The map data can in particular comprise a layout of the space, e.g. data about a layout of a building, about rooms and / or walls and / or floors, and / or e.g. data about a layout of an outdoor area, about altitudes, trees, buildings, etc.

[0053] In further embodiments, the control system can comprise a gateway, in particular wherein the listener nodes are in a (wireless) communication relationship with the gateway.

[0054] In further embodiments, the control system can comprise a localization engine, in particular wherein the localization engine is configured to determine a position of a tag based on data related to detecting a beacon signal emitted by the tag from one or more listener nodes, in particular from the plurality of listener nodes.

[0055] An asset tracking system (especially a control system) can have an operational mode. The term "operational mode" can also be indicated as "control mode". The system or device or apparatus (see further below) can perform an action in "mode" or "operational mode" or "mode of operation". Likewise, in a method, an action, phase or step can be performed in "mode" or "operational mode" or "mode of operation". This does not exclude that the system, or device, or apparatus can also be adapted to provide another control mode, or multiple other control modes. Likewise, this does not exclude that one or more other modes can be performed before and / or after performing the mode. In embodiments, however, a control system (see further below) can be available which is adapted to provide at least a control mode. If other modes are available, the selection of such mode can especially be performed via a user interface, although other options - like performing a mode according to a sensor signal or (time) scheme - can also be possible. In embodiments, the operational mode can also refer to a system, or device, or apparatus which can only operate in a single operational mode (i.e. "on", without further tunability).

[0056] The operational mode can comprise an object detection phase, a confidence region determination phase, a tag detection phase and a tag localization phase.

[0057] In embodiments, in the detection phase, the control system can (be configured to) determine the presence of an object, especially the presence of an object in a space. The term "object" can here refer to anything which can interfere with the detection of a target beacon signal by a listener node, for example by blocking the line of sight of the listener node. In particular, the object can for example be a machine, like a crane, a shelving or an art installation. The term "object" can here also refer to multiple objects.

[0058] In embodiments, the object can be associated with an object tag. In further embodiments, the object tag can be configured to emit an object beacon signal.

[0059] In embodiments, the object tag can (be configured to) emit the object beacon signal periodically. In further embodiments, the object tag can emit the object beacon signal according to a regular period, for example every 15 minutes. In yet further embodiments, however, the object tag can emit the object beacon signal according to an irregular period, for example a period which varies with the time of day, or whenever an external signal is received, or whenever the object tag moves. For example, the object tag can comprise a (passive) RFID tag, and can emit the object beacon signal upon receiving a (suitable) radio wave.

[0060] In further embodiments, the object tag can (be configured to) emit the object beacon signal (substantially) continuously.

[0061] The target beacon signal can comprise any type of signal that can be detected by multiple listener nodes. In embodiments, the beacon signal may, for example, comprise a wireless communication signal, such as a wireless communication signal selected from the group comprising a Bluetooth signal, a ZigBee (beacon packet) signal, a Li-Fi (beacon packet) signal, a Wi-Fi (beacon packet) signal, an Ultra- Wideband packet signal, and a Thread signal. In embodiments, the target beacon signal can comprise one or more carrier frequencies, in particular a plurality of carrier frequencies.

[0062] In embodiments, the object tag can be arranged on the object, in particular at a position accessible on the object - i.e. a position that can generally be accessed by a listener node for detection, e.g. a position that is relatively unobstructed for a plurality of listener nodes -. For example, the object tag can be arranged at a top corner of the object. The term "object tag" can also refer to a plurality of object tags here. In particular, for large objects, it can be beneficial to provide a plurality of object tags (at well-defined positions) such that the position and orientation of the object can be determined precisely (by the control system).

[0063] The object beacon signal can in particular comprise an object tag identification code. The object tag identification code can be specific to the object tag and can be particularly suited to uniquely identify the object tag (and in particular the object). Thereby, different object tags can be distinguished and different (tagged) objects can be tracked (independently).

[0064] The target beacon signal can further comprise a target beacon signal sequence number. The object beacon signal sequence number can be specific to the object tag for a given time and can be sequentially increased until it reaches a maximum number allowed, after which it wraps around to a minimum number allowed. Thereby, different object beacon signals can be distinguished and different object beacon signals from an object tag can be uniquely identified by, e.g., a listener for a short time period for which it is known that it is not possible to have more than one object beacon signal from an object tag with the same sequence number.

[0065] In embodiments, the plurality of listener nodes can be configured to detect (or "receive") the object beacon signal, in particular to provide a related object signal to the control system. Thus, the listener nodes can be able to detect the target beacon signal. The listener nodes can in particular passively detect the target beacon signal. In further embodiments, the listener nodes can comprise an antenna configured for detecting (or: "receiving") the target beacon signal.

[0066] The term "related" in "related object signal" can here refer to an object signal that is related to the object beacon signal, e.g. based at least in part on (the detection of) the object beacon signal.

[0067] Thus, the plurality of listener nodes can (passively) detect the target beacon signal and provide a related target signal to the control system. The control system can be (configured to) determine, based on the related target signal, whether the object is present (in the space).

[0068] For example, the plurality of listener nodes can not detect the target beacon signal (or: "no target beacon signal") and provide a related target signal to the control system. Based on the related target signal, the control system can then be (configured to) determine that the object is not present in the space. In this case, the related target signal can for example be a dedicated related target signal to indicate that no object beacon signal was detected, but it can also be an actual signal that is not sent to the control system, i.e. the plurality of listener nodes can be configured to only provide a related target signal when an object is detected.

[0069] In the confidence region determination phase, the control system can be (configured to) determine, for each listener node, a set of confidence regions based on one or more of the related target signal, the listener position data and the map data, in particular based on the related target signal, the listener position data and the map data.

[0070] The term "set of confidence regions" can here refer to a collection of one or more confidence regions for a particular listener node. Thus, each set of confidence regions can comprise one or more confidence regions. In particular, for each listener node of the plurality of listener nodes, the control system can be (configured to) divide the space into one or more confidence regions based on the related target signal, the listener position data and the map data. For example, for a particular listener node, the space can be divided into a low confidence region, a medium confidence region and a high confidence region, wherein the "view" of the listener node in the low confidence region is completely obstructed, wherein the view of the listener node in the medium confidence region is partially obstructed and / or wherein it is indeterminate whether the view of the listener node in the medium confidence region is obstructed, and wherein the view of the listener node in the high confidence region is unobstructed.

[0071] Generally, in embodiments, the set of confidence regions can in particular be an object-related set of confidence regions.

[0072] In embodiments, the confidence regions can be confidence areas and / or confidence volumes (or: "confidence spaces").

[0073] In further embodiments, the confidence regions can be confidence areas, i.e. the confidence regions can be (substantially) 2D. Using confidence areas can be beneficial, as determining confidence areas can be computationally less demanding than determining confidence volumes, which can for example facilitate faster localization of tags.

[0074] In further embodiments, the confidence region can be a confidence volume, i.e. the confidence region can be 3D. Using a confidence volume can be beneficial as it can facilitate more accurate positioning of the target tag than a confidence area, especially when the height of the target tag and / or the object corresponding to the object tag can vary.

[0075] In the tag detection phase, at least a portion of the total number of the plurality of listener nodes, in particular a sensing subset of the listener nodes (see below), can (be configured to) detect the target beacon signal and provide the related target signal to the control system. In particular, each of the plurality of listener nodes can (independently) determine a signal property upon detecting the target beacon signal. Thus, after the target tag transmits the target beacon signal, a subset of the listener nodes, also referred to as “sensing subset”, can detect (or: “receive”) the target beacon signal. Each listener node that detects the target beacon signal can then (independently) determine a signal property, wherein the signal property relates to the detection of the target beacon signal, in particular wherein the signal property is derived from the detection of the target beacon signal. In embodiments, the signal property can be selected from the group comprising signal strength, signal quality, distance estimate, angle estimate, and phase estimate. In particular, the signal property can be related to the distance between the target tag and the (respective) listener node. For example, the signal strength can decrease as the beacon signal propagates away from the target tag. Thus, if a listener node detects a beacon signal with a strong signal strength, the target tag can be nearby, whereas if a listener node detects a beacon signal with a weak signal strength, the target tag can be far away, or an object can interfere with the detection of the beacon signal by the listener node. Similarly, the signal quality can decrease as the beacon signal propagates away from the target tag, or whether an object interfered with the beacon signal as it propagated to the listener node. In embodiments, the signal property can be selected from the group consisting of signal strength (e.g. received signal strength indicator (RSSI)), signal quality, distance estimate, angle estimate, and phase estimate. In further embodiments, the signal property can comprise at least signal strength, signal quality, and / or distance estimate. The term “signal property” can also refer to multiple signal properties here.

[0076] The term “phase estimate” can refer here to an estimate related to the carrier phase difference seen by the listener in the beacon signal received from the tag when the beacon signal comprises multiple carrier frequencies. The signal on each carrier frequency can result in a phase difference with respect to the clock frequency of the listener. The phase estimate can be the total phase difference between the minimum and maximum carrier frequencies, or the phase difference averaged or normalized to a unit frequency band (e.g. 1 MHz).

[0077] The term“at the time of” can here refer to simultaneously and / or subsequently. Thus, the listener node can determine the signal property simultaneously and / or subsequently to detecting the target beacon signal. For example, the listener node can determine the signal strength of the target beacon signal (as detected) simultaneously to detecting the target beacon signal, and can determine the estimated distance (directly) subsequently to detecting the target beacon signal.

[0078] The term“signal strength” can here particularly refer to the power present in the detected beacon signal. In particular, the signal strength can correspond to a received signal strength indication (RSSI).

[0079] The term“signal quality” can here particularly refer to the quality of the detected tag beacon signal. In particular, the quality can be determined, for example, by comparing the detected target beacon signal to an (ideal) s-shaped signal. The signal quality can be indicative of how much information / trustworthiness the signal has.

[0080] In embodiments, in the operational mode, in particular in the listener node selection phase, the control system can (be configured to) determine the sensing subset of listener nodes of the plurality of listener nodes based on the set of confidence regions and / or based on the historical information, in particular based on the set of confidence regions or in particular based on the historical information.

[0081] For example, the control system can (be configured to) determine that the subset of listener nodes is (substantially) blocked by the object and can be relatively uninformative for the asset tracking, in particular for (substantially) the entire space. Thus, the control system can (be configured to) temporarily select the sensing subset of (other) listener nodes for detecting the target beacon signal, instead of continuing to have these listener nodes report data and process this data (in view of the set of confidence regions). In particular, in such embodiments, by pre-selecting the sensing subset of listener nodes, the set of confidence regions can already be taken into account for the target tag position determination.

[0082] Similarly, in embodiments, the control system can (be configured to) determine a subset of listener nodes to be relatively uninformative for the asset tracking based on the historical data. For example, the subset of listener nodes can have been historically inaccurate or previously determined to be uninformative when a particular object is in the space.

[0083] In further embodiments, in the operational mode, in particular in the tag detection phase, the sensing subset of listener nodes can (be configured to) detect the target beacon signal and provide the associated target signal to the control system.

[0084] In particular embodiments, in the operation mode, the control system can (be configured to) determine, based on the set of confidence regions, a sensing subset of listener nodes of the plurality of listener nodes; the sensing subset of listener nodes can (be configured to) detect the target beacon signal and provide a related target signal to the control system; and the control system can (be configured to) determine a target tag position (estimate) based on the related target signal, the listener position data, and the map data.

[0085] In embodiments, in the tag localization phase, the control system can (be configured to) determine a target tag position (estimate) of the target tag based on one or more of the related target signal, the listener position data, the map data, and the set of confidence regions of at least a portion of the total number of the plurality of listener nodes, in particular based on the related target signal, the listener position data, the map data, and the set of confidence regions of at least a portion of the total number of the plurality of listener nodes. In further embodiments, the control system can (be configured to) determine a target tag position (estimate) of the target tag based on one or more of the related target signal, the listener position data, and the map data, (while) in particular taking into account the set of confidence regions of at least a portion of the total number of the plurality of listener nodes based on the related target signal, the listener position data, and the map data, (while) taking into account the set of confidence regions of at least a portion of the total number of the plurality of listener nodes.

[0086] Thus, the control system can (be configured to) determine a target tag position based on the related target signal, the listener position data, the map data, and the set of confidence regions. In particular, the control system can (be configured to) weight the contribution of different listener nodes depending on the respective set of confidence regions. For example, if a target tag is estimated to be in a low confidence region of a listener node, data from this listener node can be less weighted than data from other listener nodes when determining the target tag position.

[0087] In embodiments, if it is determined that an object is present in the space, the operation mode, in particular the confidence region determination phase, can comprise the control system (being configured to) determine an object position (estimate) of the object based on the related object signal. Thus, the control system can (be configured to) determine whether an object is present based on the related object signal, and in particular, if the object is deemed to be present, can (be configured to) determine an object position (estimate) of the object based on the related object signal.

[0088] The phrase "if it is determined that an object is present in the space" and similar phrases can here refer to a part of the operational mode in which the control system checks whether an object is present in the space and, if so, performs the subsequently indicated actions. In particular, the control system can determine the presence of the object based on (input) information or can determine the presence of the object based on an object communication signal, in particular an object beacon signal.

[0089] The term "object position" can here in particular refer to an area and / or a volume occupied by the object. Thus, in embodiments, the object position can comprise a position of the object, but can in embodiments also comprise an orientation of the object. In further embodiments, the object position can comprise a representation of an area occupied by the object. In further embodiments, the object position can comprise a representation of a volume occupied by the object.

[0090] In further embodiments, the control system can (be configured to) determine the set of confidence regions for each listener node further based on the object position. In particular, for each listener node, the control system can (be configured to) divide the space into one or more confidence regions depending on the listener position data, the map data and the object position, i.e. the control system knows the position of the listener node (based on the listener position data), and the space that the listener node can typically observe (based on the map data), and to what extent the space (part of the space) is blocked by the object (based on the object position).

[0091] Determining the set of confidence regions based on the object position can provide particularly good results.

[0092] In embodiments, the object position can comprise a boundary confidence interval of the object boundary. For example, if the control system has determined the position of the object with a resolution of a few centimeters, the control system can take into account the uncertainty of the object boundary when determining the set of confidence regions for each listener node, i.e. the control system can (be configured to) determine the set of confidence regions for each listener node based on the listener position data, the map data, the object position and the boundary confidence interval.

[0093] In embodiments, the boundary confidence interval can in particular be based on an accuracy level of the asset tracking system, in particular an accuracy level of the localization engine. Thus, the skilled person will be able to select a suitable boundary confidence interval depending on the hardware of the asset tracking system. For example, in specific embodiments, the boundary confidence interval can be selected from the range of 5-30 cm, for example from the range of 15-25 cm.

[0094] In further embodiments, the control system can (be configured to) determine the set of confidence regions for each listener node based on the listener position data, the map data and the object position while taking into account the boundary confidence interval.

[0095] In embodiments, in the operational mode, in particular in the tag localization phase, the control system can (be configured to): determine a preliminary target tag position (estimate) of the target tag based on the relevant target signal, the listener position data and the map data; provide a processed signal based on the relevant target signal, the preliminary target tag position and the set of confidence regions, in particular the set of confidence regions of at least a portion of the total number of listener nodes; and determine the target tag position based on the processed signal, the listener position data and the map data. In further embodiments, the control system can (be configured to) provide the processed signal based on the relevant target signal and the preliminary target tag position, (while) taking into account the set of confidence regions.

[0096] Thus, the control system can (be configured to): first determine a preliminary target position based on the relevant target signal comprising data from the portion of listener nodes that detected the beacon signal, and then provide a processed signal based on the preliminary target tag position relative to the confidence regions in the set of confidence regions. In particular, if the preliminary target position falls in a low confidence region of a listener node, data from that listener node can be down-weighted or not incorporated into the processed signal. Thus, the processed signal can be rich in informative data relative to the relevant target signal. Next, the control system can (be configured to) determine the target tag position based on the processed signal (rather than (directly) based on the relevant target signal), which can result in a more accurate localization of the tag.

[0097] In further embodiments, each set of confidence regions can comprise a low confidence region and / or a high confidence region, and wherein in the operational mode, in particular in the tag localization phase, the control system (be configured to) provide the processed signal from the relevant target signal by omitting data from listener nodes for which the preliminary target tag position is in a (respective) low confidence region.

[0098] The phrase “omit data” can here refer to data not included in the processed signal, for example by removing data from the relevant target signal, or for example by selectively including (other) data in the processed signal.

[0099] In further embodiments, each set of confidence regions can comprise dividing the space into one or more confidence regions with an associated confidence score, in particular an associated range of confidence scores, and wherein in the operational mode, in particular in the tag localization phase, the control system can (be configured to) provide the processed signal from the relevant target signal by weighting data from listener nodes based on the (respective) confidence score associated with the respective confidence region (of the listener nodes) that includes the preliminary target tag position. Thus, data of each listener node can be weighted according to the confidence score of the respective confidence region in which the preliminary target position falls.

[0100] For example, data of a listener node whose preliminary target position lies in a low confidence region can receive a small weight, while data of a listener node whose preliminary target position lies in a medium confidence region can receive a medium weight, and data of a listener node whose preliminary target position lies in a high confidence region can receive a high weight. It will be clear to the skilled person that the greater the weight assigned to the data of a listener node, the greater the influence of the corresponding data on the determination of the target tag position can be.

[0101] In embodiments, the control system can (be configured to) determine the set of confidence regions based on a predefined confidence score, in particular a predefined confidence score range, e.g. n predefined confidence scores, in particular n predefined confidence score ranges, where n can be at least 2, e.g. at least 3. In further embodiments, n can be selected from the range of 3-20, e.g. from the range of 3-10.

[0102] Thus, in embodiments, in the operational mode, the control system can (be configured to) divide, for each listener node of the plurality of listener nodes, the space into one or more confidence regions having an associated confidence score based on one or more of the relevant object signal, listener position data and map data. In further embodiments, the control system can (be configured to) divide, for each listener node of the plurality of listener nodes, the space into one or more confidence regions having an associated confidence score based on one or more of the object position, listener position data and map data. In further embodiments, the control system can (be configured to) divide, for each listener node of the plurality of listener nodes, the space into one or more confidence regions having an associated confidence score based at least in part on one or more object properties of the object, where the object properties are selected from the group comprising shape and material. For example, the control system can (be configured to) take into account spatial variations in thickness and / or material of the object when determining the confidence regions.

[0103] In embodiments, each set of confidence regions can comprise a set of confidence volumes (or “3D confidence set”). The term “set of confidence volumes” can refer to a set of confidence regions comprising confidence regions comprising confidence volumes (see above).

[0104] In further embodiments, each set of confidence regions can comprise a set of confidence areas (or “2D confidence set”). The term “set of confidence regions” can refer to a set of confidence regions comprising confidence regions comprising confidence areas (see above).

[0105] The asset tracking system can in particular be integrated into other (pre-existing) infrastructure. In particular, in embodiments, the listener nodes can be integrated in lighting devices. The lighting devices can be equipped with a low-bandwidth wireless communication device for controlling the lighting device. For example, the light generating device can comprise or be functionally coupled to a wireless communication device, such that the light generating device can be remotely controlled. Hence, in embodiments, the wireless communication device can comprise the listener node.

[0106] The term "lighting device" can here for example refer to one or more of a light generating device, a light control element (e.g. a light switch), and an (occupancy) sensor.

[0107] In further embodiments, the asset tracking system can comprise a plurality of lighting devices, wherein (at least a part of) the plurality of listener nodes is integrated in the lighting devices.

[0108] In embodiments, at least 50% of the total number of the plurality of listener nodes can be arranged in a regular grid, e.g. a regular grid of lighting devices. The term "regular grid" can here in particular refer to a pattern formed by the intersection of two or more sets of regularly spaced parallel lines, in particular wherein the listener nodes are arranged at the intersections.

[0109] In further embodiments, the listener nodes comprised by the regular grid can be arranged at (substantially) the same height, e.g. on a ceiling.

[0110] In further embodiments, the plurality of listener nodes can further comprise one or more listener nodes which are not comprised by the regular grid and which are configured at a different height than the listener nodes configured in the regular grid.

[0111] In general, in embodiments, the target tag (or object tag) can periodically independently emit a target beacon signal (object beacon signal), i.e. the target tag (object tag) can be configured to emit the target beacon signal (object beacon signal) at regular (or irregular) intervals.

[0112] However, in embodiments, the control system can (be configured to) (have a signal generating element) emit a tracking signal, wherein the target tag (or object tag) emits the target beacon signal (or object beacon signal) upon detection of the tracking signal. In such embodiments, the control system can (enable) to locate the target tag (or object tag) at any moment, which can be beneficial if the location of the target tag (or object tag) can need to be determined in a short time, such as for example for quickly locating an expert in a hospital or factory.

[0113] Phrases like “in an operational mode, the control system can determine a target tag position”, or “in an operational mode, the control system can determine a set of confidence regions”, or “in an operational mode, the control system performs a method (of steps)”, or “in an operational mode, the control system can perform a method”, and similar phrases, can in embodiments also be understood as the control system being configured to (in an operational mode) perform the indicated action, e.g. being configured to determine a target tag position in an operational mode, or being configured to perform a method in an operational mode (of steps).

[0114] In embodiments, the asset tracking system, in particular the control system, can be configured to perform a method of the invention (see below).

[0115] In a second aspect, the invention can also provide a method for localizing a (transmitting) position of a target beacon signal in a space, in particular wherein a plurality of listener nodes is arranged in the space. In embodiments, the method can be used for localizing, in particular tracking, a target tag in the space. In embodiments, the method can comprise one or more of an object detection phase, a confidence region determination phase, a (tag) detection phase, and a (tag) localization phase.

[0116] The object detection phase can comprise determining a presence of an object (in the space) by a control system according to the invention. In embodiments, an object tag can be arranged on the object. In embodiments, the object tag and the plurality of listener nodes can be (configured to) communicate via object communication signals and provide a related object signal. Thus, the method, in particular the object detection phase, can comprise transmitting object communication signals between the object tag and the plurality of listener nodes and providing a related object signal.

[0117] The confidence region determination phase can comprise determining, by a control system according to the invention, a set of confidence regions for each listener node based on the related object signal, map data (of the space), and listener position data (of the plurality of listener nodes).

[0118] In embodiments, the (tag) detection phase can comprise transmitting target communication signals between the target tag and the plurality of listener nodes (or alternatively phrased from the target tag to the plurality of listener nodes), and providing a related target signal by the plurality of listener nodes to a control system according to the invention. Thus, the target tag and the plurality of listener nodes can be (configured to) communicate via target communication signals and provide a related target signal.

[0119] The (tag) detection phase can comprise detecting the target beacon signal with at least a portion of a total number of the plurality of listener nodes and providing a related target signal.

[0120] The (tag) localization phase can comprise determining a position based on the related target signal, the listener position data, the map data, and the confidence region set of at least a part of the total number of the plurality of listener nodes by the control system according to the application.

[0121] In embodiments, the target tag is (configured to) emit a target beacon signal. In particular, the listener nodes can be (configured to) detect the target beacon signal.

[0122] In further embodiments, the object tag is (configured to) emit an object beacon signal, in particular the object tag is (configured to) periodically emit an object beacon signal. In embodiments, the plurality of listener nodes can be configured to detect the object beacon signal, in particular to provide a related object signal.

[0123] In embodiments, the plurality of listener nodes can be configured to emit a listener node signal. In further embodiments, the target tag can be configured to detect the listener node signal. In further embodiments, the object tag can be configured to detect the listener node signal.

[0124] In embodiments, the (tag) detection phase can comprise detecting the target beacon signal with at least a part of the total number of the plurality of listener nodes, and providing a related target signal.

[0125] Thus, in particular embodiments, the application provides a method for localizing a position of a target beacon signal in a space, wherein a plurality of listener nodes is arranged in the space, wherein the listener nodes are configured to detect the target beacon signal, wherein the method comprises: (a) determining a presence of an object, wherein an object tag is arranged on the object, and wherein the object tag periodically emits an object beacon signal, wherein the plurality of listener nodes is configured to detect the object beacon signal and to provide a related object signal; (b) determining a confidence region set for each listener node based on the related object signal, map data, and listener position data; (c) detecting the target beacon signal with the plurality of listener nodes, and providing a related target signal; and (d) determining a position based on the related target signal, the listener position data, the map data, and the confidence region set of at least a part of the total number of the plurality of listener nodes.

[0126] The phrase "a method for localizing a position of a target beacon signal" and similar phrases can also be interpreted in embodiments as a method for localizing a position of a tag (emitting a beacon signal).

[0127] In embodiments, the method, in particular the object detection stage, can comprise determining an object position (estimate) of the object based on the relevant object signal, if it is determined that an object is present in the space. In further embodiments, the method, in particular the confidence region determination stage, can comprise determining a confidence region set for each listener node further based on the object position.

[0128] In embodiments, the method, in particular the (tag) localization stage, can comprise determining a preliminary position (estimate) of the target tag based on the relevant target signal, the listener position data, and the map data. In further embodiments, the method, in particular the (tag) localization stage, can comprise providing a processed signal from the relevant target signal based on the relevant target signal, the preliminary position (of the target tag), and the confidence region set of at least a portion of the total number of the plurality of listener nodes. In such embodiments, the method, in particular the (tag) localization stage, can further comprise determining the position based on the processed signal, the listener position data, and the map data.

[0129] In embodiments, each confidence region set can comprise a low confidence region and / or a high confidence region, i.e. the confidence region set can comprise a single high (or low) confidence region, or can comprise a low confidence region and a high confidence region.

[0130] In further embodiments, the method, in particular the (tag) localization stage, can comprise providing a processed signal from the relevant target signal by omitting data from listener nodes whose preliminary position is in a (respective) low confidence region.

[0131] In embodiments, each confidence region set can comprise dividing the space into one or more confidence regions having an associated confidence score. In such embodiments, the method can comprise providing a processed signal from the relevant target signal by weighting data from listener nodes based on a (respective) confidence score associated with a respective confidence region (of the listener nodes) that includes the preliminary position.

[0132] In embodiments, at least 50% of the total number of the plurality of listener nodes can be arranged in a regular grid, in particular wherein one or more listener nodes not comprised by the regular grid, in particular “off-grid listener nodes”, are configured at a different height than listener nodes configured in the regular grid. Thus, the plurality of listener nodes can comprise one or more off-grid listener nodes.

[0133] In another aspect, the present application can provide a computer program product comprising instructions for execution on a computer functionally coupled to the plurality of listener nodes, wherein the instructions, when executed by the computer, cause the computer to perform at least part of the steps of the method of the present application.

[0134] In embodiments, the computer program product can be executed by a computer functionally coupled to the asset tracking system to cause the asset tracking system to perform at least part of the steps of the method of the application.

[0135] In another aspect, the application can provide a data carrier carrying program instructions which, when executed by a computer functionally coupled to a plurality of listener nodes, cause the computer to perform at least part of the steps of the method of the application.

[0136] In another aspect, the application can provide a lighting device comprising at least one listener node as defined herein for use in an asset tracking system as defined herein. In a particular embodiment, the (above) method for locating a (transmitting) position of a (tagged) beacon signal in a space can use such a lighting device.

[0137] In embodiments, the lighting device can comprise a light generating device, a light control element or a (proximity) sensor, in particular can comprise a light generating device, more in particular can comprise a luminaire.

[0138] The lighting device can be part of, or can be applied in, for example, an office lighting system, a home application system, a shop lighting system, a home lighting system, a spot lighting system, a spotlight lighting system, a theater lighting system, a fiber application system, a projection system, a self-luminous display system, a pixelated display system, a segmented display system, a warning sign system, a medical lighting application system, an indication sign system, a decorative lighting system, a portable system, a motor vehicle application, a greenhouse lighting system, horticulture lighting, etc.

[0139] In a particular embodiment, the light source comprises a solid state LED light source (e.g. a LED or laser diode).

[0140] The term “light source” can also relate to a plurality of light sources, e.g. 2-20 (solid state) LED light sources. Hence, the term LED can also refer to a plurality of LEDs. BRIEF DESCRIPTION OF DRAWINGS

[0141] Embodiments of the application will now be described, by way of example only, with reference to the accompanying schematic drawings in which corresponding reference signs indicate corresponding parts, and in which:

[0142] Figures 1A-1B An embodiment of an asset tracking system is schematically depicted;

[0143] Figure 2 A further embodiment of an asset tracking system is schematically depicted;

[0144] Figure 3Further embodiments of an asset tracking system are schematically depicted.

[0145] The schematic drawings are not necessarily to scale. DETAILED DESCRIPTION

[0146] Figures 1A-1B An embodiment of an asset tracking system 100 for tracking a target tag 10 in a space 500 is schematically depicted. The asset tracking system 100 can comprise a plurality of listener nodes 110 arranged in the space 500. The asset tracking system 100 can comprise a control system 300, in particular wherein the control system 300 has access to one or more of listener location data and map data. In an embodiment, the asset tracking system can have an operational mode wherein:

[0147] - the control system 300 can (be configured to) determine a presence of an object 200, wherein the object tag 210 is associated with the object 200. In an embodiment, the object tag 210 and the plurality of listener nodes 110 are configured to communicate via object communication signals and provide a related object signal to the control system 300. In a further embodiment, the object tag 210 can be configured to emit an object beacon signal, wherein the plurality of listener nodes 110 are configured to detect the object beacon signal and provide a related object signal to the control system 300;

[0148] - the control system 300 can determine a set of confidence regions 230 for each listener node 110 based on the related object signal, the listener location data and the map data;

[0149] - the plurality of listener nodes 110 and the target tag 10 can (be configured to) communicate via target communication signals and provide a related target signal to the control system 300. In an embodiment, the target tag can (be configured to) emit a target beacon signal, in particular wherein the plurality of listener nodes 110 can (be configured to) detect the target beacon signal and provide a related target signal to the control system 300; and

[0150] - the control system 300 can determine a target tag location of the target tag 10 based on the related target signal, the listener location data, the map data, and the set of confidence regions 230 of the plurality of listener nodes 110.

[0151] Figure 1A Two object tags 210 associated with an object 200 are schematically depicted.

[0152] In embodiments, if the object 200 is determined to be present in the space 500, the operational mode can comprise controlling the system 300 to determine an object position 250 of the object 200 based on the relevant object signal. In the depicted embodiment, the object position 250 can comprise a boundary confidence interval of the boundary of the object 200. Thus, the target position 250 is a larger space than the target 200 itself in order to account for the uncertainty in the target position 250.

[0153] In further embodiments, the control system 300 can be configured to determine a confidence region set 230 for each listener node 110 based on the listener position data, the map data, and the object position 250.

[0154] Figure 1B The same embodiment is schematically depicted with Figure 1A the confidence regions 231 of the confidence region set 230 of the first listener node 110, 110a. In particular, Figure 1B The space is schematically depicted to be divided into three confidence regions 231, 231a, 231b, 231c of the first listener node 110, 110a based on the object position 250. Specifically, a first confidence region 231, 231a can be a low confidence region, wherein the first confidence region comprises a region that is estimated to be directly obstructed by the object 200 at the object position 250. A second confidence region 231, 231b can be a medium confidence region, wherein the second confidence region 231, 231b comprises a region that can be obstructed by the object 200 due to some uncertainty of the object position 250 (with respect to the first listener node 110, 110). A third confidence region 231, 231c can be a high confidence region, wherein the third confidence region can comprise a region that is considered not to be obstructed by the object 200 (with respect to the first listener node 110, 110a) based on the object position 250.

[0155] In embodiments, in the operational mode, the control system 300 can determine a preliminary target tag location 15 of the target tag 10 based on the relevant target signals, the listener location data, and the map data. Next, the control system 300 can provide processed signals based on the relevant target signals, the preliminary target tag location 15, and the set of confidence regions 230 of the plurality of listener nodes 110. For example, in the depicted embodiment, the control system 300 can determine that the preliminary target tag location 15 is located in a first confidence region 231, 231a of the set of confidence regions 230 of the first listener node 110, where the first confidence region 231, 231a is a low confidence region. Accordingly, the control system 300 can provide the processed signals by (optionally in addition to other modifications) providing a lower weight to the first listener node 110, 110a or omitting data of the first listener node 110, 110a. The control system 300 can then determine the target tag location based on the processed signals, the listener location data, and the map data. Since data from the blocked listener node(s) 110 can be weighted less and / or ignored, the estimated target tag location can be more accurate than the preliminary target tag location (estimate) 15.

[0156] In further embodiments, each set of confidence regions 230 can include one or more confidence regions 231 dividing the space 500 with an associated confidence score, and where in the operational mode, the control system 300 can provide processed signals from the relevant target signals by weighting data from listener nodes 110 based on the confidence score associated with the respective confidence region 231 that includes the preliminary target tag location 15. In the depicted embodiment, with respect to the first listener node 110, 110a, the set of confidence regions 230 can include three confidence regions 231. In embodiments, different listener nodes 110 of the plurality of listener nodes 110 can differ in the number of confidence regions 231 in their respective confidence sets 230.

[0157] Figures 1A-1BFurther embodiments of a method for localizing a (transmitting) position, in particular a target tag position, of a target beacon signal in a space 500, in particular for tracking a target tag 10 in the space 500, are schematically depicted. In particular, a plurality of listener nodes 110 can be arranged in the space 500. In embodiments, the method can comprise determining a presence of an object 200, wherein an object tag 210 is arranged on the object 200. In particular, the object tag 210 and the plurality of listener nodes 110 can be configured to communicate via object communication signals and to provide related object signals. In particular, in embodiments, the object tag 210 can be configured to transmit an object beacon signal, wherein the plurality of listener nodes 110 are configured to detect the object beacon signal and to provide related object signals; determining a set of confidence regions 230 for each listener node 110 based on the related object signals, map data, and listener position data; transmitting target communication signals between the target tag 10 and the plurality of listener nodes 110 and providing related target signals. In particular, in embodiments, the target tag 10 can be configured to transmit a target beacon signal, and the method can comprise detecting the target beacon signal with the plurality of listener nodes 110 and providing related target signals; and determining a position based on the related target signals, the listener position data, the map data, and the set of confidence regions 230 of the plurality of listener nodes 110.

[0158] Figure 1B Further embodiments of the method are schematically depicted, wherein, if it is determined that the object 200 is present in the space 500, the method comprises determining an object position 250 of the object 200 based on the related object signals; and determining the set of confidence regions 230 for each listener node 110 based on the listener position data, the map data, and the object position 250.

[0159] In the depicted embodiments, the method further comprises determining a preliminary position, in particular a preliminary target tag position 15, based on the related target signals, the listener position data, and the map data; providing a processed signal based on the related target signals, the preliminary position, and the set of confidence regions 230 of the plurality of listener nodes 110; and determining a position based on the processed signal, the listener position data, and the map data.

[0160] In the depicted embodiments, the method can comprise dividing the space 500 into one or more confidence regions 231 having an associated confidence score, and in particular providing the processed signal from the related target signals by weighting data from the listener nodes 110 based on the confidence score associated with the respective confidence region 231 including the preliminary position, in particular the preliminary target tag position 15.

[0161] Figure 2Further embodiments of the asset tracking system 100 are schematically depicted. In the depicted embodiments, the set of confidence regions 230 of the first listener node 110, 110a can take into account objects 200 like walls in the space (500).

[0162] In the depicted embodiments, the second listener node 110, 110b can be substantially completely occluded (in terms of field of view) by the object 200. Thus, in the operational mode, the control system 300 can determine the sensing subset 111 of listener nodes of the plurality of listener nodes 110 based on the set of confidence regions 230. In particular, the second listener node 110, 110b can be excluded from the sensing subset 111 of listener nodes. In further embodiments, the sensing subset 111 of listener nodes can detect the target beacon signal and provide the related target signal to the control system 300, in particular, the control system 300 can stop the detection of listener nodes 110 excluded from the sensing subset 111 of listener nodes.

[0163] In the depicted embodiments, each set of confidence regions 230 can comprise low confidence regions and / or high confidence regions, and wherein in the operational mode: the control system 300 can provide the processed signal from the related target signal by omitting data from listener nodes 110 in low confidence regions of the preliminary target tag location 15. Thus, in the depicted embodiments, data from the first listener node 110, 110a can be omitted (depending on the preliminary target tag location 15) with respect to the positioning of the first target tag 10, 10a, but included in the processed signal with respect to the positioning of the second target tag 10, 10b.

[0164] Figure 2 Further embodiments are schematically depicted, wherein at least 50% of the total number of the plurality of listener nodes 110 are arranged in the regular grid 115, and wherein the plurality of listener nodes 110 further comprises one or more listener nodes 110, in particular off-grid listener nodes 118, which are not comprised by the regular grid 115 and are in particular configured at a different height than the listener nodes 110 comprised by the regular grid 115.

[0165] Figure 2 Further embodiments of the method of the invention are schematically depicted, wherein each set of confidence regions 230 comprises low confidence regions and / or high confidence regions, and wherein the method comprises providing the processed signal from the related target signal by omitting data from listener nodes 110 in low confidence regions of the preliminary location.

[0166] Figure 3Another embodiment of the asset tracking system 100 is schematically depicted, wherein at least a part of the total number of listener nodes 110 is integrated in a lighting device 1000. In particular, Figure 3 A lighting device 1000 is schematically depicted, comprising a light generating device such as a lamp 1001 and a luminaire 1002, and a lighting control element 1003 such as a user interface, e.g. a graphical user interface. Reference sign 1010 denotes light generated by the lighting device 1000. In particular, this light is visible light, e.g. white light. The lighting control element 1003 can also be a portable device, e.g. an I-phone or a smart phone.

[0167] Figure 3 Also schematically depicted is an embodiment of the lighting device 1000, wherein the lighting device 1000 comprises at least one listener node 110 of the application for use in the asset tracking system 100 of the application.

[0168] The term "a number of" refers to two or more. Also, the terms "a number of" and "several" can be used interchangeably.

[0169] The term "substantially" or "essentially" and similar terms in the present text will be understood by the skilled person. The term "substantially" or "essentially" can also include embodiments with "completely", "entirely", "all" etc. Hence, in embodiments, the adjective substantially or essentially can also be removed. Where applicable, the term "substantially" or the term "essentially" can also relate to 90% or more, such as 95% or more, in particular 99% or more, even more particularly 99.5% or more, including 100%. Also, the terms "about" and "approximately" can also relate to 90% or more, for example 95% or more, in particular 99% or more, even more particularly 99.5% or more, including 100%. For numerical values, it will be understood that the terms "substantially", "essentially", "about" and "approximately" can also relate to a range of 90-110%, for example 95-105%, in particular 99-101% of the numerical value(s) they refer to.

[0170] The term "comprising" also includes embodiments where the term "comprising" is interpreted as "consisting of".

[0171] The term "and / or" relates in particular to one or more of the items that are referred to before and after the "and / or". For example, the phrase "item 1 and / or item 2" and similar phrases can relate to one or more of item 1 and item 2. The term "comprising" can in one embodiment mean "consisting of", but can in another embodiment also mean "containing at least the defined kind and optionally one or more further kinds".

[0172] Furthermore, the terms first, second, third, etc. have been used, both in the specification and in the claims, to describe similar elements, and are not necessarily used to describe sequential or chronological order. It will be understood that the terms so used are interchangeable under appropriate circumstances and that the embodiments of the application described herein are capable of operating in other sequences than described or illustrated herein.

[0173] During operation, an apparatus, device, or system can be described herein, among other things. As will be apparent to those of ordinary skill in the art, the application is not necessarily limited to the methods of operation, or the apparatus, devices, or systems, in operation.

[0174] The term "further embodiments" and similar terms can refer to embodiments that include features of previously discussed embodiments, but can also refer to alternative embodiments.

[0175] It should be noted that the above-mentioned embodiments illustrate rather than limit the application, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims.

[0176] In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim.

[0177] The use of the verb "comprise" and its conjugations does not exclude the presence of elements other than those stated in the claims. Unless the context clearly requires otherwise, throughout the description and the claims, the words "comprise", "comprising", "include", "including" and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in the sense of "including, but not limited to".

[0178] The article "a" or "an" preceding an element does not exclude the presence of a plurality of such elements.

[0179] The application can be implemented by means of hardware comprising several distinct elements, and by means of a suitably programmed computer. In the device claim enumerating several means, several of these means can be embodied by one and the same item of hardware. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

[0180] The present invention also provides a control system, which can control a device, an apparatus or a system, or which can execute a method or a procedure as described herein. Yet further, the present invention also provides a computer program product, which, when running on a computer functionally coupled to or comprised by a device, an apparatus or a system, controls one or more controllable elements of such device, apparatus or system.

[0181] The term "control" and similar terms herein refer to, among others, determining a behavior of an element or supervising a running of an element. Thus, "control" and similar terms herein can refer to, for example, imposing a behavior on an element (determining a behavior or supervising a running of an element), such as, for example, measuring, displaying, actuating, opening, moving, changing a temperature, etc. In addition thereto, the term "control" and similar terms can additionally include monitoring. Thus, the term "control" and similar terms can include imposing a behavior on an element, as well as imposing a behavior on an element and monitoring the element. The control of the element can be done with a control system. Thus, the control system and the element can be functionally coupled at least temporarily or permanently. The element can comprise the control system. In embodiments, the control system and the element can not be physically coupled. The control can be done via wired and / or wireless control. The term "control system" can also refer to a plurality of different control systems, which are functionally coupled, and wherein, for example, one control system can be a master control system, and one or more other control systems can be slave control systems.

[0182] The present invention is also applicable to a device, an apparatus or a system comprising one or more features described in the description and / or shown in the attached drawings. The present invention also relates to a method or procedure comprising one or more features described in the description and / or shown in the attached drawings. Furthermore, if a method or an embodiment of the method is described as being performed in a device, an apparatus or a system, it will be understood that the device, apparatus or system, respectively, is suitable for or configured to (perform) the method or the embodiment of the method.

[0183] The various aspects discussed in this patent can be combined to provide additional advantages. Furthermore, those skilled in the art will appreciate that embodiments can be combined and more than two embodiments can also be combined. In addition, some features can form the basis of one or more divisional applications.

[0184] The present invention relates, among others, to a coordination system and can comprise at least two steps. In a first step, the listeners close to the transmitting tag are informing and negotiating with each other. Furthermore, a top listener can be selected in a distributed manner based on the measurements they each have. In a second step, the measurement results of all selected listeners are transmitted by the selected listeners individually or by one or more reporting listeners that have been selected in the first step. The destination of the reporting can be a gateway of the network.

Claims

1. An asset tracking system (100) for tracking a target tag (10) in a space (500), wherein the asset tracking system (100) comprises a plurality of listener nodes (110) arranged in the space (500), and wherein the asset tracking system (100) comprises a control system (300), wherein the control system (300) has access to (i) listener position data and (ii) map data, characterized in that, In an operation mode: - the control system (300) is configured to determine a presence of an object (200), wherein an object tag (210) is associated with the object (200), and wherein the object tag (210) and the plurality of listener nodes (110) are configured to communicate via object communication signals and to provide related object signals to the control system (300); - the control system (300) determines a set of confidence regions (230) for each listener node (110) based on the related object signals, the listener position data, and the map data; - the target tag (10) and the plurality of listener nodes (110) are configured to communicate via target communication signals and to provide related target signals to the control system (300); and - the control system (300) determines a target tag position of the target tag (10) based on the related target signals, the listener position data, the map data, and the set of confidence regions (230) of the plurality of listener nodes (110).

2. The asset tracking system (100) according to claim 1, wherein the target tag (10) is configured to emit a target beacon signal, and wherein the object tag (210) is configured to emit an object beacon signal, and wherein in the operation mode: - the plurality of listener nodes (110) are configured to detect the object beacon signal and to provide related object signals to the control system (300); and - the plurality of listener nodes (110) are configured to detect the target beacon signal and to provide related target signals to the control system (300).

3. The asset tracking system (100) according to any of the preceding claims, wherein, If it is determined that an object (200) is present in the space (500), in the operation mode: - the control system (300) is configured to determine an object position (250) of the object (200) based on the related object signals; and - the control system (300) is configured to determine a set of confidence regions (230) for each listener node (110) further based on the object position (250).

4. The asset tracking system (100) according to claim 1 or 2, wherein, In the operation mode: - the control system is configured to determine a sensing subset (111) of listener nodes of the plurality of listener nodes (110) based on the set of confidence regions (230); and - the sensing subset (111) of listener nodes is configured to detect target beacon signals and to provide related target signals to the control system (300).

5. The asset tracking system (100) of claim 1 or 2, wherein, In the operation mode: - the control system (300) is configured to determine a preliminary target tag position (15) of the target tag (10) based on the related target signals, the listener position data, and the map data; - the control system (300) is configured to provide a processed signal based on the related target signals, the preliminary target tag position (15), and the set of confidence regions (230) of the plurality of listener nodes (110). - the control system (300) is configured to determine the target tag position based on the processed signal, the listener position data and the map data.

6. The asset tracking system (100) of claim 5, wherein, Each set of confidence regions (230) comprises a low confidence region and / or a high confidence region, and wherein in the operational mode: - the control system (300) is configured to provide the processed signal from the correlated target signal by omitting data from listener nodes (110) for which the preliminary target tag position (15) is in the low confidence region.

7. The asset tracking system (100) of claim 6, wherein, Each set of confidence regions (230) comprises one or more confidence regions (231) dividing the space (500) with an associated confidence score, and wherein in the operational mode: - the control system (300) is configured to provide the processed signal from the correlated target signal by weighting data from listener nodes (110) based on a confidence score associated with the respective confidence region (231) comprising the preliminary target tag position (15).

8. The asset tracking system (100) of claim 1 or 2, wherein, At least a portion of the total number of the plurality of listener nodes (110) is integrated in a lighting device (1000), and wherein at least 50% of the total number of the plurality of listener nodes (110) is arranged in a regular grid (115).

9. A method for tracking a target tag (10) in a space (500), wherein a plurality of listener nodes (110) is arranged in the space (500), wherein the method comprises: - determining, by a control system (300), a presence of an object (200) for which an object tag (210) is arranged, and wherein the object tag (210) and the plurality of listener nodes (110) are configured to communicate via object communication signals, and the plurality of listener nodes provide a correlated object signal to the control system; - determining, by a control system (300), for each listener node (110) a set of confidence regions (230) based on the correlated object signal, map data and listener position data; - transmitting, from the target tag (10), a target communication signal to the plurality of listener nodes (110), and providing, by the plurality of listener nodes, a correlated target signal to the control system; and - determining, by a control system (300), a position of the target tag based on the correlated target signal, the listener position data, the map data, and the set of confidence regions (230) of the plurality of listener nodes (110).

10. The method according to claim 9, wherein the target tag (10) is configured to emit a target beacon signal, and wherein the object tag (210) is configured to emit an object beacon signal, and wherein the method comprises: - detecting, with the plurality of listener nodes (110), the object beacon signal, and providing the correlated object signal; and - detecting, with the plurality of listener nodes (110), the target beacon signal, and providing the correlated target signal.

11. The method according to any of the preceding claims 9-10, wherein, If it is determined that an object (200) is present in the space (500), the method comprises: - determining an object position (250) of the object (200) based on the correlated object signal; and - determining a set of confidence regions (230) for each listener node (110) further based on the object position (250).

12. The method according to claim 9 or 10, wherein the method comprises: - determining a preliminary position of the target tag based on the correlated target signal, the listener position data and the map data; - providing a processed signal based on the correlated target signal, the preliminary position, and the set of confidence regions (230) of the plurality of listener nodes (110); and - determining a position of the target tag based on the processed signal, the listener position data and the map data.

13. The method according to claim 12, wherein each set of confidence regions (230) comprises one or more confidence regions (231) dividing the space (500) with an associated confidence score, and wherein the method comprises: - providing the processed signal from the correlated target signal by weighting data from listener nodes (110) based on confidence scores associated with respective confidence regions (231) including the preliminary position.

14. The method according to claim 9 or 10, wherein at least 50% of the total number of the plurality of listener nodes (110) are arranged in a regular grid (115), and wherein the plurality of listener nodes (110) comprises one or more off-grid listener nodes (118) not included by the regular grid and configured at a different height than listener nodes (110) configured in the regular grid (115), and wherein at least a portion of the total number of the plurality of listener nodes (110) are integrated in a lighting device (1000). ​

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