Wireless Anchor for Asset Tracking

Abstract

This technology enables the localization of asset tracking tags (102, 104, 414, 426) based on one or more beacon signals (412) from at least one anchor beacon (105, 410, 424). Each of the beacon signals (412) contains anchor beacon identification information and is associated with the received signal strength upon reception by a reader device (106, 416, 428). The anchor beacon identification information is associated with the physical location of the anchor beacon (105, 410, 424). The location of the reader device (106, 416, 428) is estimated according to the received signal strength of one or more beacon signals (412) and the physical location of at least one anchor beacon (105, 410, 424) from the anchor beacon identification information. One or more signals (412) from the asset tracking tags (102, 104, 414, 426) are detected by the reader device (106, 416, 428). The location of the asset tracking tags (102, 104, 414, 426) is identified based on the estimated location of the reader device (106, 416, 428) and the signal strength information for each of the one or more detected signals from the asset tracking tags (102, 104, 414, 426).

Description

Technical Field

[0001] Cross - Reference to Related Applications

[0001] This application claims the benefit of the filing date and priority of U.S. Patent Application No. 17 / 830,510, filed on June 2, 2022, the entire disclosure of which is incorporated herein by reference.

Background Art

[0002] Background

[0002] The Internet of Things (IoT) is the network connectivity of physical objects such as products, packages, vehicles, buildings, etc., in which electronic components for network connection are embedded. The embedded components enable the object to detect other objects, be detected by other objects, collect data, and / or transmit data. In some examples, the embedded components may include tags or labels attached to the physical object. These tags or labels may be passive or active. The network connectivity capability can be utilized to track the location of physical objects. In many situations, an object may be moved at different times, such as a package or equipment moved from a truck to the shipping dock of a warehouse, or a medical device moved between different rooms (or floors) in a hospital. In such types of situations, it can be difficult to determine the location of the object with appropriate accuracy, including updating the location when it changes. In addition, systems that use GPS or Wi - Fi can be hampered by signal dropout or the transmitter going offline, thereby reducing the ability to correctly identify the location of the object.

Summary of the Invention

Means for Solving the Problems

[0003] Brief Summary

[0003] The disclosed embodiments improve the positioning accuracy of objects by using anchor beacons within the operating area of the system. The anchor beacons may be placed in different locations such as inside and around a room, a storage area, an exit, etc., and their relative positions or exact positions are known. For example, a given anchor beacon may be placed in one corner of a conference room, and the system may know the corner where the anchor beacon is located, or the room in which the anchor beacon is placed. By employing anchor beacons, the system can more easily identify the positions of reader devices and asset tracking tags within the system based on the known positions of the anchor beacons.

[0004]

[0004] According to one aspect, a method for positioning an asset tracking tag includes detecting, by a reader device, one or more beacon signals from at least one anchor beacon, each of the detected beacon signals including anchor beacon identification information, each of the detected beacon signals being associated with a received signal strength at the time of reception by the reader device, the anchor beacon identification information being associated with the physical location of the anchor beacon, estimating, by one or more processors, the position of the reader device according to the received signal strength of one or more beacon signals and the physical location of at least one anchor beacon from the anchor beacon identification information, detecting, by the reader device, one or more signals from the asset tracking tag, and identifying, by one or more processors, the position of the asset tracking tag based on the estimated position of the reader device and the signal strength information for each of the one or more detected signals from the asset tracking tag.

[0005] Estimating the position of the reader device may include comparing the received signal strength of one of the one or more beacon signals with calibration data in which the physical positions of at least one anchor beacon are already stored. Comparing the received signal strength of one of the one or more beacon signals with calibration data in which the physical positions of at least one anchor beacon are already stored may include performing a second comparison for another received signal strength from different anchor beacons. The calibration data may include at least one of environmental information of the operating area or electromagnetic signature information of the operating area.

[0006]

[0006] The method may further include obtaining, by the reader device, reader environment information related to the surrounding environment of the reader device, and each of the detected beacon signals may further include anchor beacon environment information related to the surrounding environment of at least one anchor beacon. Estimating the position of the reader device may include comparing the reader environment information with the anchor beacon environment information. One or more signals from the asset tracking tag may include asset tracking tag environment information related to the surrounding environment of the asset tracking tag.

[0007]

[0007] Identifying the position of the asset tracking tag may be further based on the asset tag environment information and the reader environment information. Identifying the position of the asset tracking tag may include identifying at least one of the room or floor in which the asset tracking tag is located. Identifying at least one of the room or floor of the asset tracking tag may include determining whether the asset tag environment information and the reader environment information match.

[0008]

[0008] According to another aspect, the system is configured to locate an asset tracking tag. The system includes at least one anchor beacon, at least one reader device, and a memory configured to store location information for one or more of the at least one anchor beacon, the at least one reader device, or the at least one asset tracking tag. The system also includes one or more processors operatively coupled to the memory, the one or more processors being configured to: obtain one or more beacon signals from the at least one anchor beacon, each of the obtained beacon signals including anchor beacon identification information, each of the obtained beacon signals being associated with a received signal strength upon reception at the at least one reader device, the anchor beacon identification information being associated with a physical location of the anchor beacon; estimate a location of the at least one reader device according to the physical location of at least one anchor beacon from the received signal strength of the one or more beacon signals and the anchor beacon identification information; obtain one or more signals from the at least one asset tracking tag; and identify a location of the at least one asset tracking tag based on the estimated location of the at least one reader device and signal strength information for each of the one or more obtained signals from the at least one asset tracking tag. The at least one anchor beacon may be stationary at a physical location. The one or more processors may be one or more processors of the at least one reader device.

[0009]

[0009] Alternatively or additionally to any of the above, the system may further include a central server, and the one or more processors may be one or more processors of the central server. The central server may be configured to send at least one of the positions of at least one reader device or at least one asset tracking tag to the client device. The at least one anchor beacon may be a plurality of anchor beacons, the at least one reader device may be a plurality of reader devices, and the at least one asset tracking tag may be a plurality of asset tracking tags. Each of the plurality of anchor beacons may be located in a different room or floor within the operating area of the system.

[0010]

[0010] Alternatively or additionally to any of the above, the memory may be further configured to store calibration data, and the estimation of the position of the reader device may further include a comparison of the received signal strength of one of the one or more beacon signals and the physical position of at least one anchor beacon with the stored calibration data. The at least one anchor beacon, the at least one reader device, and the at least one asset tracking tag may be configured to collect environmental information, and the estimation of the position of the reader device may include a comparison of the environmental information of at least one reader device and the environmental information of at least one anchor beacon. The at least one reader device may be stationary or movable.

Brief Description of the Drawings

[0011] Brief Description of the Drawings

Figure 1A

[0011] Various examples of object positioning according to aspects of the technology are shown.

Figure 1B

[0012] FIG. 1 is a functional diagram of an exemplary tracking system according to an aspect of the present disclosure.

Figure 2

[0013] FIG. 2 is a diagram of an exemplary network according to an aspect of the present disclosure.

Figure 3

[0014] It is a functional diagram of an exemplary network according to an aspect of the present disclosure, as shown in FIG. 2.

Figure 4A

[0015] An exemplary scenario is shown according to an aspect of the present disclosure.

Figure 4B

[0015] An exemplary scenario is shown according to an aspect of the present disclosure.

Figure 5

[0016] An exemplary method is shown according to an aspect of the present disclosure.

Mode for Carrying Out the Invention

[0012] Detailed Description Examples of Systems

[0017] The accurate location identification of an object may be important for several reasons, including knowing where a replacement or device is stored and whether additional substances need to be ordered. In a warehouse environment, pallets of goods can be moved to different locations when they arrive at the warehouse, when storage limits are reached, when the goods need to be transported, and depending on the destination of the goods. In a commercial or hospital environment, equipment is stored in one location (e.g., a storage room), placed in different rooms for use, and then moved as needed, such as when a hospital bed needs to be moved from one room to another.

[0013]

[0018] Locating an object can be difficult because different storage areas, rooms, floors, etc. may have different wireless transmission characteristics. This may be affected by signal reflections (e.g., multipath signals) caused by walls or objects within that area. Additionally, there may be noise or interference from wireless signals of other types of communication devices using the same signal spectrum or overlapping signal spectra.

[0014]

[0019] Figure 1A shows examples of different objects in various environments. As shown in the left - hand image of the figure, there may be packages or equipment on a pallet inside a warehouse. The pallet may be outside a freight truck, as shown by the "in transit" image in the middle of the figure. The pallet may be moved to one or more different positions inside the warehouse by, for example, a forklift as shown in the left - hand image. The right - hand image of the figure shows a situation where medical equipment (e.g., a wheelchair) and supplies in a box can be stored in a hospital supply room.

[0015]

[0020] In all of these situations, inside a warehouse, on a freight truck, or throughout a hospital, the object of interest may move around. This may be with respect to different aisles or rooms inside the warehouse, different rooms (or even different floors) in a hospital, or different parts of the cargo container of a truck. In the latter case, the cargo may be shifted during transit or rearranged when different packages are delivered to different locations. Knowing the current location of the object of interest, rather than where it is presumed to be based on its initial placement, is useful information for an office manager, a warehouse manager, a nurse, or a porter. Ideally, such people should be able to easily have the current location of a given object presented on their own client computing device, such as a laptop, a mobile phone, or a smartwatch (or other wearable computing device).

[0016]

[0021] Figure 1B is a functional diagram of an exemplary tracking system 100. The tracking system 100 can include a plurality of tracking devices such as tracking tags 102 and 104, one or more anchor beacons 105, and a reader 106. As will be described further below, a server computing device 108 may also be part of the tracking system 100. Each tracking tag can include one or more sensors, an identifier chip (for radio frequency (RF) identification, etc.), and / or a transmission device (such as an RF module configured to transmit information using a selected frequency band and transmission protocol). The tracking tag may be passive, such as a tag configured to be operated by environmental energy or powered, or active, such as a tag that includes a battery or is configured to be coupled to another power source. A given tracking tag can be placed, attached, or inserted onto an item to be tracked, such as a package, device, vehicle, compartment of a warehouse, room, etc. Tracking tag 102 is associated with an asset such as a package, device, or vehicle (e.g., an autonomous fulfillment robot capable of retrieving packages from different locations within a forklift or warehouse), and tracking tag 104 may be a beacon tag configured to transmit beacon information from a passageway within a warehouse or from a specific room within a hospital. Customer needs for accuracy and "liveliness" can vary. For example, a customer may only want to know the passageway-level accuracy daily (e.g., before the warehouse closes at night), while another customer, such as a nurse in a hospital, may need to know hourly where a device is located so that it is accessible when a patient needs it.

[0017]

[0022] A given asset tracking tag 102 or beacon tracking tag 104 can emit a signal via an antenna, such as by using a transmitting device, to communicate data. The data is formatted according to a selected protocol and can include one or more sensed characteristics of the given tracking tag or its environment. For example, the sensed characteristics may be temperature, location, movement, battery state, movement / item status, and / or other detectable characteristics of the tracking device or its environment. The transmitting device can transmit such information by radio frequency transmission in a selected frequency band using a standard or proprietary protocol. By way of example, the transmitting device may employ Bluetooth (trademark) (e.g., Bluetooth Low Energy (BLE)) or the 802.11 protocol in the 2.4 GHz and / or 5 GHz frequency bands. In some examples, each anchor beacon and each asset tracking tag use the Bluetooth (trademark) or BLE protocol.

[0018]

[0023] One or more anchor beacons 105 are present at fixed and known physical locations within the operating range of the system, such as within the geographical area of a warehouse, an office building or park, a hospital complex, etc. For example, when each anchor beacon 105 is set up, its physical location (e.g., Room 301 on the 3rd floor of a hospital, or Box 22 on Shelf 3 in Aisle 26 of a warehouse) is recorded and stored in a spreadsheet or other database within the system's memory. The anchor beacon can emit signals via an antenna, such as by using a transmission device to communicate data. The data is formatted according to a selected protocol and may include one or more sensed characteristics of a given anchor beacon or its environment. For example, the sensed characteristics may be temperature, location, movement, battery state, movement / item state, and / or other detectable characteristics of the anchor beacon or its surrounding environment (e.g., the environment of the room or the location within the warehouse where the anchor beacon is located). The transmission device may transmit such information via radio frequency transmission in a selected frequency band using a standard or proprietary protocol. By way of example, the transmission device may employ Bluetooth (trademark) (e.g., Bluetooth Low Energy (BLE)) or the 802.11 protocol in the 2.4 GHz and / or 5 GHz frequency bands. In some examples, each anchor beacon uses the Bluetooth (trademark) or BLE protocol.

[0019]

[0024] Reader 106 may be a computing device configured to detect signals emitted by a plurality of tracking tags 102 and 104 and one or more anchor beacons 105, and store and / or transmit data related to the tracking tags. Although only one reader is shown in FIG. 1B, the system may employ multiple readers. Reader 106 may include one or more processors 110, a memory 112, and other components typically present in a general-purpose computing device. Reader 106 includes a communication module 118 having an antenna and a processing section (not shown), and the processing section may include a bandpass filter for the target frequency band, an analog-to-digital (A / D) converter, and a signal processing module for evaluating information in the received signal. The processing section may also convert the received signal to a baseband signal, either before or after A / D conversion. Communication module 118 may include a separate receiver and transmitter sub-module, or an integrated transceiver configured to receive signals from tracking tags 102, 104 and / or anchor beacon 105 according to the protocol used by those devices. Communication module 118 may also be configured to communicate with server computing device 108. Reader 106 may be stationary or movable (e.g., on a hospital cart or an employee's mobile device).

[0020]

[0025] One or more processors 110 may be a commercially available CPU or microcontroller. Alternatively, one or more processors may be a dedicated device such as an ASIC, or other hardware-based processor such as a field programmable gate array (FPGA). FIG. 1B functionally shows the processor, memory, and other elements of the reader 106 as being within the same block, but the processor, computing device, or memory may actually include multiple processors, computing devices, or memories that may or may not be stored within the same physical housing. For example, the memory may be a hard drive, removable USB drive, or other storage medium located in a housing different from that of the reader 106. Thus, a reference to a processor or computing device is understood to include a collection of processors or computing devices or memories that may or may not operate in parallel.

[0021]

[0026] Memory 112 stores information accessible by one or more processors 110, including instructions 114 and data 116 that may be executed by the processor 110 or otherwise used. The data may include characteristics sensed from either tag 102 and / or 104 received by the reader 106. Memory 112 may be any type capable of storing information accessible by a processor, including a computing device readable medium, or other medium such as a hard drive, memory card, ROM, RAM, DVD, or other optical disk, and other writeable and read-only memories. The system and method may include different combinations of the foregoing, whereby different portions of the instructions and data are stored on different types of media.

[0022]

[0027] Data 116 can be retrieved, stored, or modified by processor 110 according to instruction 114. For example, although the claimed subject matter is not limited to any particular data structure, the data may be stored in a computing device register in a relational database as a table having a plurality of different fields and records, an XML document, or a flat file. The data may also be formatted in any computing device readable format.

[0023]

[0028] Instruction 114 may be any set of instructions that are executed directly (such as machine code) or indirectly (such as a script) by a processor. For example, the instructions may be stored as computing device code on a computing device readable medium. In this regard, the terms "instructions" and "program" may be used interchangeably herein. The instructions may be stored in object code format for direct processing by the processor or in any other computing device language including scripts or collections of independent source code modules that are interpreted upon request or pre-compiled. The functions, methods, and routines of the instructions are described in detail below.

[0024]

[0029] In some embodiments, the tracking system 100 may further include a central server, such as one or more server computing devices 108 accessible by one or more processors 110 of the reader 106. In some embodiments, one or more tracking devices of the tracking system 100, such as the tracking tag 104 and the anchor beacon 105, may be configured to acquire data and communicate the data directly to the server computing device 108. The server computing device 108 may include one or more processors 120, a memory 122, and other components typically present in a general-purpose computing device. The one or more processors 120 may be of the same or similar type as the one or more processors 110, and the memory 122 may be of the same or similar type as the memory 112. The memory 122 stores information accessible by the one or more processors 120, including instructions 124 and data 126 that may be executed by the processors 120 or otherwise used. The data 126 and instructions 124 may be of the same or similar type as the data 116 and instructions 114, respectively. The server computing device includes a communication module 128, which may be configured for communication with the communication module 118 of one or more readers 106 and for communication with the anchor beacon 105 and / or the tracking tag 104 according to the protocols used by those devices. Similar to the communication module 118, the communication module 128 may include separate receiver and transmitter sub-modules, or an integrated transceiver.

[0025]

[0030] After detecting the signals of one or more tracking tags 102 or 104 and one or more anchor beacons 105, the reader 106 may use the communication module 118 to transmit data from the tracking tags and anchor beacons to the server computing device 108 through an existing connection or network. The data may be received in a series of payloads (e.g., data packets) intermittently, at one or more set intervals, or ad hoc whenever the tracking tags transmit. Thus, when multiple tracking tags and / or anchor beacons are present, the data is effectively received as multiple separate data streams. A given payload (which may include one or more data packets) may include measurements taken at one or more time intervals, each of which may have a corresponding timestamp. In one scenario, the reader 106 may include a transceiver that includes both a receiver and a transmitter, the transceiver being configured to receive signals from the tags 102 and 104 and the anchor beacon 105 and further to transmit and receive information with the server computing device 108.

[0026]

[0031] The server computing device 108 can be configured to track the characteristics of a tracking tag for one or more alerts based on multiple conditions. The multiple conditions can include at least one condition for each characteristic, such as a minimum value, a maximum value, a threshold value, a period, and / or a geopence. The conditions can be predetermined or set based on user input. For example, a first alert may be set when (1) the temperature is higher than a threshold temperature, such as 0°C to 10°C for 30 minutes, and (2) the tracking device is in motion, which may indicate overheating of a cooling package or a storage compartment. A second alert may be set when (1) no movement is detected for 10 minutes, (2) two out of three positions are within a geopence, and (3) the tracking device is in motion, which may indicate that the package is out for delivery. A third alert may be set when (1) a threshold amount of light is detected from inside the package and (2) the tracking device is in motion, which may indicate an unexpected opening or tampering of the package. A fourth alert may be set when (1) a threshold amount of light is detected from inside the package and (2) two out of three positions are within the destination geopence, which may indicate that the package has been opened after delivery or receipt. Many other alert conditions and tracking scenarios are possible, and the above examples are not intended to be limiting.

[0027]

[0032] The tracking system 100 can optionally include an application that can be installed on one or more client computing devices. Using the application, the client computing device can access data from the reader 106 and / or the central server 108 through the network and the corresponding communication modules of the reader and / or the central server.

[0028]

[0033] FIG. 2 and FIG. 3 are a drawing and a functional diagram, respectively, of an exemplary system 200 including a plurality of client computing devices 220, 230, 240 and a storage system 250 connected via a network 260. System 200 also includes a tracking system 100 including tracking tags 102, 104, anchor beacon 105, and reader 106, and server computing device 108. For simplicity, only a few tags, anchor beacons, and computing devices are shown, but a typical system may include significantly more.

[0029]

[0034] Using a client computing device, a user such as user 222, 232, or 242 can view location data on a display such as displays 224, 234, 244 of their respective computing devices 220, 230, 240. As shown in FIG. 3, each client computing device 220, 230, 240 may be a personal computing device intended for use by a respective user, and may include one or more processors (e.g., a central processing unit (CPU)), a memory for storing data and instructions (e.g., RAM and an internal hard drive), a display such as displays 224, 234, 244 (e.g., a monitor having a screen, a touch screen, a head-mounted display, a smartwatch display, a projector, a television, or other device operable to display information), and user input devices 226, 236, 246 (e.g., a mouse, a keyboard, a touch screen, and / or a microphone). The client computing device may also include all of the components typically used to connect to and operate such a personal computing device, including speakers, a network interface device, and components used to interconnect these elements.

[0030]

[0035] Client computing devices 220, 230, and 240 may each include a full-sized personal computing device, or alternatively, may include a mobile computing device capable of wirelessly exchanging data with a server via a network such as the Internet. By way of example only, client computing device 220 may be a device such as a mobile phone, or a wireless-enabled PDA, tablet PC, wearable computing device or system (e.g., a smartwatch or head-mounted display, or a netbook capable of obtaining information via the Internet or other network). By way of example, a user may input information using a small keyboard, keypad, microphone that uses visual signals (gestures) having a camera or other sensor, or a touch screen.

[0031]

[0036] Figure 4A shows an example 400 of a system having several tracking tags arranged at various positions in a building (e.g., a hospital). In this example, along one side of a corridor 404, there may be several rooms 402 such as patient rooms. On the opposite side of the corridor 404, there is a storage room 406 for accommodating equipment or supplies and another room 408, which may be a meeting room, a shared area, a rehabilitation facility, etc. One or more anchor beacons 410 may be located in each room including the corridor. Each anchor beacon 410 is configured to emit a beacon signal 412 (e.g., an RF signal in a frequency band specifically selected according to a communication protocol). By way of example, the beacon signal 412 may be a Bluetooth (trademark) or BLE signal that is periodically transmitted at intervals of several seconds, several minutes, or more or less frequently. Alternatively, the signal may be transmitted when a specific condition or event occurs (detecting that a threshold temperature and / or humidity has been reached, or detecting a signal from one or more reader devices). The beacon signal 412 may appear to be directional, but it does not have to be, and the signal may be transmitted omnidirectionally from an anchor beacon 410 located, for example, on the ceiling, a pillar, or the floor. In some embodiments, the anchor beacon 410 may be configured to emit an RF signal having information related to its environment (e.g., temperature, humidity, etc.).

[0032]

[0037] In addition to the anchor beacon 410, asset tags 414 may be present on various items (e.g., a case of supplies as shown in the storage room 406, or a wheelchair as shown in the room 402A). Each asset is also configured to emit an RF signal having information related to that asset (e.g., temperature, motion information, item details, and / or other detectable characteristics of the tracking device or its environment) in the manner described above. Readers 416 may be found at various locations within the building, such as in patient rooms, storage rooms, corridors, or other places. It should be noted that even when transmitted omnidirectionally, the signal from a given anchor beacon or asset tag may be attenuated non-uniformly due to the presence of obstacles such as walls, furniture, floor / ceiling, equipment, etc.

[0033]

[0038] Figure 4B shows another example 420 of a system for placing several anchor beacons along different aisles within a warehouse environment. In this example, there are several aisles 422A - 422D, although there could be more (or fewer) aisles, and the aisles could be arranged in other configurations than those shown. Here, the anchor beacon 424 may be located at different locations along the aisle, such as along the end caps of the aisle, along the ceiling (or floor), on top of shelves, in storage lockers, cabinets, or other locations along the aisle. Similar to Figure 4A, the tracking tag 426 is placed on or otherwise associated with different assets, such as a pallet or forklift of equipment for retrieving items from their locations within the warehouse. As described above, the anchor beacon and the asset tracking tag are configured to transmit signals detectable by one or more readers 428.

[0034] Example of method

[0039] In addition to the aspects described above and shown in the figures, various operations are described here. It should be understood that the following operations need not be performed in the exact order described below.

[0035]

[0040] According to one aspect of the technology, the system is configured to determine the position of an item having a tracking tag (e.g., tag 102 shown in FIG. 1B). To track an item, the system may need the position of the tracking tag on each item, on a package containing multiple items, on a pallet storing several packages, etc. As described herein, the system performs position determination using beacon transmissions received from one or more tracking tags 104 and one or more anchor beacons 105. The one or more tracking tags 104 and the one or more anchor beacons 105 are detected by one or more readers 106. Since the position of the anchor beacon 105 is fixed and known within the system, the reader 106 or the server computing device 108 may utilize the anchor beacon for position determination. In an embodiment, when the reader 106 is movable, the position of the reader can be determined based on transmissions from one or more of the anchor beacons 105. Once the position of the reader is known, the system can easily identify where different assets are located by the signals received by the reader from the corresponding asset tracking tags. This can be done in an indoor environment such as a warehouse, a trailer of a cargo truck, a hospital room, etc. However, in other situations, the detection may occur outdoors or within a partially enclosed structure.

[0036]

[0041] In one example, each beacon tracking tag 104 and anchor beacon 105 transmits beacon signals or information signals at regular intervals or defined intervals. The intervals may be every few seconds, every few minutes, or longer or shorter. The beacon signal transmissions can be received by one or more readers 106 of the system. The readers may be stationary or movable. The tracking tag transmissions include data such as a tracking tag identifier or other identification information, and the signal strength at the time of transmission by the tracking tag (e.g., initial signal strength or transmission power). The identifier or other identification information is unique to each tracking tag (such as a unique equipment serial number (ESN) or mobile equipment identifier (MEID) number) and enables the identification of each individual tracking tag within the system. Similarly, the anchor beacon transmissions include data such as an anchor beacon identifier or identification information, and the signal strength at the time of transmission by the anchor beacon (e.g., initial signal strength or transmission power). The identifier or identification information is unique to each anchor beacon (e.g., ESN or MEID number) and enables the identification of each individual anchor beacon within the system. Additionally, since the positions of the anchor beacons within the system are fixed and known, the system can identify the positions of the anchor beacons associated with each anchor beacon transmission by the identifier or identification information.

[0037]

[0042] When the reader receives beacon signal transmission from a tracking tag or an anchor beacon, the reader may timestamp the signal (since the transmission of a beacon, e.g., one or more data packets, may not include any transmission timestamp) and detect the received signal strength. The timestamp corresponds to the time when the signal was received by the reader, and the received signal strength is the power level of the signal when received by the reader. In one scenario, the reader may process the information locally, but in other scenarios, the reader transmits the signal information to another device such as a central server. The reader transmission includes data such as an identifier associated with the tracking tag or anchor beacon that transmitted each beacon, the initial signal strength, the timestamp, and the received signal strength detected from the transmission received from both the anchor beacon and the tracking tag. The reader may also transmit an identifier or other identification information associated with the reader. The reader may record an estimate of its own position when the signal was received. Alternatively or in addition, other environmental information may be recorded when the reception of a signal from a tracking tag (e.g., temperature, humidity, or changes thereof) is recorded. The acquired environmental information relates to conditions from the environment around or surrounding the reader (e.g., the environment of the room or part of the warehouse where the reader is currently located). All of this information may be transmitted to a central server. In some embodiments, the reader is stationary and may or may not record or transmit this additional information (e.g., an estimate of its own position, environmental information from its surrounding environment).

[0038]

[0043] The central server first processes data from the reader to perform position determination for the reader (or the reader may process the data locally). In one embodiment, the central server may do this, for example, by calculating the distance between the anchor beacon and the reader based on the received signal strength over at least one time step (and / or the difference between the received signal strength and its initial signal strength), where the distance is a function of the received signal strength. The central server may utilize data including the same beacon tracking tag identifier from multiple readers (i.e., corresponding to the same tracking tag and / or related item). The central server may repeat the distance calculation for the received signal strength over at least one time stamp received from multiple readers. The central server may then perform position determination based on the calculated relative distances between each reader and the beacon tracking tag.

[0039]

[0044] In another embodiment, the central server may determine the position of the reader based on a comparison with calibration data of received signal strength. The calibration data includes previously calculated and estimated received signal strength values corresponding to positions within the operating range of the system for one or more anchor beacons of the system. The estimated received signal values may be determined, for example, by calculating received signal strength values estimated based on the distance between the anchor beacon and the position. The estimated received signal strength value is a function of the distance and the anchor beacon position is known. Additionally, the calibration data may include environmental information (e.g., temperature, humidity, etc.) and a map of the operating range of the system, and these may be taken into account. The calibration data can be used to simulate different types of environments in order to estimate how strong the signal is in each room. In some embodiments, the central server may take environmental information into account by comparing information received from the tracking tag, the reader, or both with known environmental conditions within the operating range of the system, and may determine the position within the operating range of the system where the received information matches the known conditions. The system may assign a high probability (e.g., increase the probability value) that the tag and / or reader is at the position determined based on the environmental condition match. Such determination may additionally be used in room or floor position determination, which will be described in more detail below.

[0040]

[0045] In some embodiments, additional system calibration can be performed within the operating range of the system. For example, the mobile reader and asset tracking tags can be moved throughout the operating range and communicate with stationary anchor beacons and readers to enable fine-tuning of calibration data. In one example, calibration within the operating range can enable the calibration data to take into account objects and barriers within the system (e.g., the floor, walls, windows, and / or objects within the room). In another example, calibration within the operating range enables measurement of the electromagnetic (EM) signature at different locations. Due to the EM signature of the location, the received beacon signal may be different from the previously estimated signal strength included in the calibration data. Calibration performed within the operating range allows the calibration data to take into account the EM signature present within the operating range and be updated with the EM signature. Such calibration is particularly advantageous at locations where there are stationary or regularly present devices that generate EM radiation. For example, in a hospital environment, equipment adapted to take computed tomography (CT) scans may generate a significant amount of EM radiation during use. Similarly, devices used in radiation treatment facilities such as linear accelerators and remote afterloaders can also generate EM radiation that affects the received signal strength. In some embodiments, such calibration can occur both when the device is operating and when it is not operating.

[0041]

[0046] After receiving data including the first received signal strength from a given anchor beacon from a first reader, the central server may compare the first received signal strength with calibration data. Based on the comparison, the central server determines the distance between the first reader and the given anchor beacon at the first timestamp. The central server may repeat the comparison for the second received signal strength from a second anchor beacon at the first timestamp corresponding to the same reader. The central server may repeat the comparison with additional received signal strengths from additional anchor beacons at the first timestamp corresponding to the same reader according to, for example, a multilateration process. For example, the multilateration process may include location-specific information such as a site map including, for example, obstacles and the positions of anchor beacons, and characteristics regarding individual rooms included in the site map. The characteristics may include measured values such as temperature. In some situations, the multilateration process may utilize a probabilistic approach described in more detail below. The central server may then perform location determination with increased accuracy based on the comparison between each anchor beacon and the reader. The comparison may be repeated at additional timestamps.

[0042]

[0047] In one aspect, the system may approximately estimate the log-likelihood that a given reader is present in each “cell” of a grid that may be virtually provided at that location (e.g., one floor of a building). This may employ a Bayesian approach based on a linear mapping of received signal strength to distance. Refinement is possible by location filtering such that the position of the beacon is probabilistically related to its previously estimated position (e.g., using a Kalman filter). This enables an extended location determination for the reader and ultimately for tracking tags associated with various other objects (assets).

[0043]

[0048] In another aspect, beacon-reader calibration enables the system to build a probabilistic model around the tolerance of noisy received signal strength indications (from beacon to reader). Receiver filtering may be performed, whereby the system can counter noisy signals by dynamically weighting or removing indications outside of an expected range. At that point, an iterative Gauss-Newton method for non-linear least squares (NLLS) can be used to find an optimal position prediction as a function of the remaining indications from the reader.

[0044]

[0049] In this approach, Bayesian estimation may be performed using prior information about the device based on manufacturer tolerances, in which case the likelihood is identified by data collected off-site. Bayesian estimation may also incorporate and account for possible transmissions through walls, floors, and other barriers likely to be present in the system's operating range. Information about such barriers can be used in the estimation. As a result, a posterior distribution (e.g., p(distance|observed rssi)) for noisy received signal strength (RSSI) indications per receiver (reader) versus distance is obtained. Receiver (reader) dynamic filtering may involve median-mean filtering over a time window for each reader-anchor beacon pair to filter out noisy values. It may also include a threshold for known / acceptable distance measurements between an anchor beacon and a reader. For example, each time an inference is made, the system may filter out unrealistic and / or temporally large-changing (e.g., 100 meters change in 0.5 seconds from one measurement to the next) distance measurements. This can provide another layer of robustness against noise (e.g., by temporarily moving a forklift, a person walking around with an electronic device, etc.).

[0045]

[0050] The NLLS approach may be framed as an optimization task where the system attempts to minimize the error over all observed data points. For example,

Number

Number

Number

[0046]

[0051] According to one aspect, position tracking can be performed as follows. Within a single prediction window (e.g., 1 to 20 minutes), if the number of packets received for a single transmission rate (e.g., packets per transmission) is less than a threshold such as a minimum sample count (the minimum number of packets such as at least 3 to 7 packets received to perform an evaluation), the received signal strength value for that transmission rate is ignored. If it is more than the minimum sample count, the system uses an aggregation function to aggregate the RSSI values to generate a single smoothed RSSI value. The aggregation function can be, for example, the MAX function that returns the maximum value from a set of RSSI values.

[0047]

[0052] One algorithm includes the following operations. First, it fetches data corresponding to a given prediction window for a single beacon. Next, it individually aggregates RSSI values for each transmission speed using the above-described method. Then, it uses the aggregated RSSI values to obtain a distance estimate of a given reader to each anchor beacon. Next, it obtains an initial estimate of the reader position by a grid search process that uses the distance estimate (see below). The initial estimate can then be supplied as the starting estimate to the NLLS method. The NLLS method further optimizes the reader position prediction using this initial estimate and the distance estimate.

[0048]

[0053] The distance estimate can be performed according to a machine learning algorithm. The purpose is to estimate the distance of the beacon from each reader using RSSI values for different transmission speeds. For each transmission speed, a separate regression algorithm is trained. For example, when tx = -20, a regression model may be trained using the RSSI values for the transmission speed of tx = -20, where the RSSI value is the predictor variable and the distance is the target variable. This method takes into account the priority of the transmission speed. For example, -20 > -16 > -12 > -8 > -4 > 0 > 2 > 4 is an example of the priority order. The above priority order indicates that the regression model for tx = -20 is prioritized over the regression model for tx = -16, etc. The logical basis for such a priority order is that the spread of RSSI for tx = -20 for a given distance interval may be narrower compared to the RSSI for tx = 4. In a given prediction window, the distance can be estimated using only one regression model for a single tx. The regression model can be selected based on the above-described priority. Thus, if it is possible to obtain the aggregated RSSI value for tx = -20 in a given prediction window, the regression model for tx = -20 is used for prediction, and if not, the system attempts to use the regression model for tx = -16, and so on.

[0049]

[0054] When the system estimates the distances from the readers to the anchor beacons, the next step is to find the points in the continuous space that best fit those distance estimates. In a grid search, the system can divide the 3D space into 1-meter x 1-meter x 1-meter cubes (or larger or smaller cubes) based on the dimensions of the area of interest. Each cube is represented by its centroid, and the error for each cube is calculated using Equation (1) as described above.

[0050]

[0055] Finally, when the positions of the different readers are determined, those positions are stored in a database such as the database 250 of FIG. 2. When the readers and the central server obtain more recent information (e.g., data packets received from the anchor beacons), the positions of the readers in the database can be updated accordingly. In some examples, when the reader is first placed in position, the user can enter the XY coordinates of its position information relative to the origin of the building and the altitude associated with the floor on which the reader is located. Such XY coordinates may be converted to latitude / longitude (with or without other height information such as altitude or floor or level).

[0051]

[0056] After determining the reader position, the central server can then perform a position determination on the tracking tag for which it will send a message (or the reader can process the data locally). The central server can perform this determination in the same manner as described above in the determination of the reader position by adding the known reader position. For example, the central server can perform a position determination of the tracking tag based on a comparison with calibration data of the received signal strength. After determining the reader position, the calibration data is updated at the reader position so that the calibration data can be used here for the determination of the position of the tracking tag. The updated calibration data includes estimated received signal strength values corresponding to positions within the operating range of the system for one or more anchor beacons of the system and the reader whose position was previously determined at a given time step. The estimated received signal value can be determined, for example, by calculating an estimated received signal strength value based on the distance between the reader and the position. The estimated received signal strength value is a function of the distance and the reader position is known. Additionally, the calibration data includes information such as temperature, humidity, and a map of the operating range of the system and takes them into account.

[0052]

[0057] After receiving data including the first received signal strength from the tracking tag from the first reader, the central server can compare the first received signal strength with the calibration data. Based on the comparison, the central server determines the distance between the tracking tag and the reader at the first timestamp. The central server may repeat the comparison for the second received signal strength from the second reader whose position was determined at the first timestamp corresponding to the same reader. The central server may repeat the comparison with additional received signal strengths from additional readers whose positions were determined at the first timestamp corresponding to the same tracking tag according to the above-described multilateration process or the like. The central server may also implement a Bayesian approach including a probabilistic model, the NLLS method, etc., as described above in the determination of the position of the tracking tag.

[0053]

[0058] In some embodiments, the tracking tag position determination may only need to identify the room and / or floor. The granularity can be determined based on different factors, including customer selection, the type of item or product being tracked, information about the location itself, etc. In such embodiments, the central server may only need to determine whether the received signal strength exceeds a threshold. The threshold is determined as a function of signal attenuation representing the lowest possible received signal value for a beacon within a particular floor's room. This determination of room and / or floor identification can be similarly utilized in reader position determination. For example, when the reader receives a beacon signal from a tracking tag or anchor beacon where the received signal strength is below the threshold, the central server determines that there is no reader within the same room and / or floor as the anchor beacon or tracking tag. On the other hand, when the received signal strength exceeds the threshold, the central server determines that there is a reader within the same room and / or floor as the anchor beacon or tracking tag. When the signal corresponds to an anchor beacon and its room and floor location is known, the central server can determine the room and floor location of the reader based on the comparison of the received signal strength and the threshold. Once the central server determines the room and floor location of the reader, the central server can determine the room and floor location of the tracking tag in the same manner. This determination can be repeated for multiple readers and tracking tags in the system.

[0054]

[0059] Furthermore, this room and / or floor determination may be used alone or in combination with the above-described location determination. In embodiments where the room and / or floor determination is used in combination with the location determination, it may be utilized to further filter out unlikely locations. For example, if a reader or tracking tag is determined to be in a particular room or floor, the central server may update the calibration data to reflect such a determination (e.g., assign a high probability, 80 - 95% or more, that the reader or tag is in a particular room), enabling a more precise location determination. In some embodiments, the determination of whether the tracking tag and reader are in the same room, on the same floor, or both, may include a comparison of environmental information. For example, the central server may compare environmental information received from the tracking tag, reader, or both, with environmental conditions detected by known environmental conditions in the system's operating area or stationary anchor beacons, and determine a location within the system's operating range where the received information matches the known conditions. The system may assign a high probability (e.g., increase the probability value) that the tag and / or reader is at the location determined based on the match of environmental conditions. For example, if the environmental conditions detected by the tracking tag match the first reader but not the second reader, the central server may determine that the tracking tag is not in the same room or floor as the second reader and increase the probability that the tracking tag is in the same room or floor as the first reader. For example, the conditions may be determined to match when their values are within a range of about 5% - 15% of each other, or within a range of 2 - 4 degrees Celsius with respect to temperature. According to another example, the match for a given condition may be determined by whether the difference in values is less than a threshold difference related to that condition. The same process may be applied to the reader and the first and second anchor beacons. This determination is particularly advantageous in an operating system having temperature-controlled parts (e.g., refrigerated trucks, food storage facilities).

[0055]

[0060] In some embodiments, the central server may use proximity data in location determination, including determining whether the tracking tag and the reader are in the same room, on the same floor, or both. Proximity data may be generated by a reader or tracking tag that interacts with a device (e.g., a laptop, a desktop, a stationary medical device, etc.) known to be in a particular room or floor, whether mobile or stationary. Proximity data may be generated when the tracking tag or reader is within a distance range of the device (e.g., 1 - 4 meters, or greater or less than that). In some embodiments, proximity data may be generated as a result of the interaction between one or more ultrasonic speakers and one or more microphones of the tracking tag and / or reader and one or more ultrasonic speakers and one or more microphones of the device. The ultrasonic speakers and microphones may be limited in range to a particular room because ultrasound is significantly attenuated by the walls and / or floor of the room, enabling verification of the position of the tracking tag and / or reader within the same room and floor as the device.

[0056]

[0061] In some embodiments, proximity data may be used in conjunction with the techniques described above. For example, based on proximity data, if the tracking tag or reader is determined to be in a particular room and / or floor, the multilateration technique is updated with that determination and its computational area is limited to the particular room and / or floor. In certain situations, if partial multilateration is performed that suggests a signal should be present in a room where there is no signal, either the target object is actually in a different location or there is an obstacle in the room that is preventing detection of the target object. If other targets are discovered in this situation, the likelihood that the target object is in that room may decrease.

[0057]

[0062] Based on the above, FIG. 5 shows an exemplary method 500 for locating an asset tracking tag. At block 502, the method comprises detecting, by a reader device, one or more beacon signals from at least one anchor beacon, each of the detected beacon signals including anchor beacon identification information and each of the detected beacon signals being associated with a received signal strength upon reception at the reader device. The anchor beacon identification information is associated with the physical location of the anchor beacon. At block 504, the method comprises estimating, by one or more processors, the location of the reader device according to the received signal strength of the one or more beacon signals and the physical location of at least one anchor beacon from the anchor beacon identification information. At block 506, the method comprises detecting, by the reader device, one or more signals from the asset tracking tag. At block 508, the method comprises identifying, by one or more processors, the location of the asset tracking tag based on the estimated location of the reader device and the signal strength information for each of the one or more detected signals from the asset tracking tag.

[0058]

[0063] Unless otherwise specified, the alternative examples described above are not mutually exclusive, but can be implemented in various combinations to achieve unique advantages. Since these and other variations and combinations of the features described above can be utilized without departing from the subject matter defined by the claims, the description of the foregoing embodiments should be received as illustrative rather than as a limitation of the subject matter defined by the claims. In addition, the examples described herein and the provision of clauses expressed as "such as", "including", etc. should not be construed as limiting the subject matter of the claims to specific examples, but rather, the examples are intended to show only one of many possible embodiments. Further, the same reference numbers in different drawings may identify the same or similar elements.

Claims

1. A method for locating an asset tracking tag, comprising: detecting, by a reader device, one or more beacon signals from at least one anchor beacon, each of the detected beacon signals including anchor beacon identification information, each of the detected beacon signals being associated with a received signal strength upon reception at the reader device, and the anchor beacon identification information being associated with a physical location of the anchor beacon; estimating, by one or more processors, a location of the reader device according to the received signal strength of the one or more beacon signals and the physical location of the at least one anchor beacon from the anchor beacon identification information; detecting, by the reader device, one or more signals from the asset tracking tag; identifying, by the one or more processors, a location of the asset tracking tag based on the estimated location of the reader device and signal strength information for each of the one or more detected signals from the asset tracking tag; A method comprising the above.

2. The method according to claim 1, wherein estimating the location of the reader device includes comparing the received signal strength of one of the one or more beacon signals and the physical location of the at least one anchor beacon with calibration data that has been stored.

3. The method according to claim 2, wherein comparing the received signal strength of one of the one or more beacon signals and the physical location of the at least one anchor beacon with the stored calibration data includes performing a second comparison for another received signal strength from a different anchor beacon.

4. The method according to claim 2, wherein the calibration data includes at least one of environmental information of the operating area or electromagnetic signature information of the operating area.

5. The method according to claim 1, further comprising obtaining, by the reader device, reader environmental information related to the surrounding environment of the reader device, wherein each of the detected beacon signals further includes anchor beacon environmental information related to the surrounding environment of the at least one anchor beacon.

6. The method according to claim 5, wherein estimating the position of the reader device includes comparing the reader environment information with the anchor beacon environment information.

7. The method according to claim 5, wherein the one or more signals from the asset tracking tag include asset tracking tag environment information related to the surrounding environment of the asset tracking tag.

8. The method according to claim 7, wherein identifying the position of the asset tracking tag is further based on the asset tracking tag environment information and the reader environment information.

9. The method according to claim 8, wherein identifying the position of the asset tracking tag includes identifying at least one of a room or a floor in which the asset tracking tag is located.

10. The method according to claim 8, wherein identifying at least one of a room or a floor of the asset tracking tag includes determining whether the asset tag environment information and the reader environment information match.

11. A system configured to locate at least one asset tracking tag, at least one anchor beacon, at least one reader device, a memory configured to store position information about one or more of the at least one anchor beacon, the at least one reader device, or at least one asset tracking tag, one or more processors operably coupled to the memory, the one or more processors being acquiring one or more beacon signals from the at least one anchor beacon, each of the acquired beacon signals including anchor beacon identification information, each of the acquired beacon signals being associated with a received signal strength upon reception by the at least one reader device, and the anchor beacon identification information being associated with a physical position of the anchor beacon, estimating the position of the at least one reader device according to the physical position of the at least one anchor beacon from the received signal strength of the one or more beacon signals and the anchor beacon identification information, acquiring one or more signals from the at least one asset tracking tag, and Identifying the position of the at least one asset tracking tag based on the estimated position of the at least one reader device and the signal strength information for each of the one or more acquired signals from the at least one asset tracking tag by the one or more processors, One or more processors configured to perform the above, A system comprising the above.

12. The system according to claim 11, wherein the at least one anchor beacon is stationary at the physical position.

13. The system according to claim 11, wherein the one or more processors are one or more processors of the at least one reader device.

14. Further comprising a central server, The system according to claim 11, wherein the one or more processors are one or more processors of the central server.

15. The system according to claim 14, wherein the central server is configured to transmit at least one of the position of the at least one reader device or the position of the at least one asset tracking tag to a client device.

16. The system according to claim 11, wherein the at least one anchor beacon is a plurality of anchor beacons, the at least one reader device is a plurality of reader devices, and the at least one asset tracking tag is a plurality of asset tracking tags.

17. The system according to claim 16, wherein each of the plurality of anchor beacons is located in a different room or floor within the operating area of the system.

18. The memory is further configured to store calibration data, and the estimation of the position of the reader device includes a comparison of the received signal strength of one of the one or more beacon signals with the physical position of the at least one anchor beacon and the stored calibration data. The system according to claim 11.

19. The at least one anchor beacon, the at least one reader device, and the at least one asset tracking tag are configured to collect environmental information, and the estimation of the position of the reader device includes a comparison of the environmental information of the at least one reader device with the environmental information of the at least one anchor beacon. The system according to claim 11.

20. The system according to claim 11, wherein the at least one reader device is stationary or movable.

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