Wireless sensing units, systems, methods, and media

Abstract

Wireless sensing units, methods, systems, and processor readable media for obtaining pressure data related to one or more pressure locations of a surface area are described. A wireless sensing system includes a pressure monitoring device that communicates with modular wireless smart floor tiles using RFID, RFID reader or wireless network interface (e.g. 802.11). The tiles have passive or active RFID tags. The tiles can be powered wirelessly using magnetic resonance by a built-in piezoelectric power unit or by a wireless power source, etc. Data acquisition circuitry in each tile collects and saves data for transmission to the floor pressure monitoring device. The smart floor system can initiate various software applications including fall detection and prediction, gesture input, intrusion detection, and user location tracking to enable smart home automation.

Description

[0001] Cross-reference to related applications

[0002] This application claims the benefit of U.S. non-provisional application No. 17 / 107,208, entitled “Wireless sensing units, systems, methods, and media,” filed November 30, 2020, which is incorporated herein by reference. Technical Field

[0003] This application generally relates to human-machine interfaces and smart home sensors, and more specifically to wireless sensing units, methods, systems, and processor-readable media for collecting pressure data associated with multiple pressure locations on a surface area. Background Technology

[0004] Sensing environment is a human-computer interaction (HCI) approach that aims to enable users to interact with virtual or real environments through natural human movement and behavior in spaces equipped with sensors (such as cameras or microphones).

[0005] One sensing method that can be used to sense the environment is the use of floor-based sensors to detect the presence and / or activity of humans or other objects on a floor surface. Existing floor-based sensors typically involve a network of pressure sensors beneath the floor surface. The sensor network receives power from a power source (e.g., building wiring) and communicates via a wired communication interface (e.g., Ethernet) or a wireless communication interface (typically 802.11 or Bluetooth). TM It communicates with data processing equipment.

[0006] These existing methods have several limitations. First, sensor networks require underground power cables to power the sensors; and in some cases, data cables to acquire sensor data. Second, sensors are typically wired in series, so a failure, malfunction, or damage to one part of the sensor network can render the entire network unusable. Isolating the fault in the sensor network and repairing or replacing the faulty part may also require removing the floor covering all parts of the sensor network. Furthermore, the analog data generated by the sensors in the sensor network typically needs to be collected and processed by data processing equipment; as the sensor network grows in size, this data collection and processing can become unmanageable.

[0007] Therefore, there is a need for a floor-based sensor system that overcomes one or more of the limitations of existing methods. Summary of the Invention

[0008] Described herein are wireless sensing units, methods, systems, and processor-readable media for obtaining pressure data related to a plurality of pressure locations of a surface area such as a floor. A wireless sensing system for obtaining pressure data can include a wireless pressure monitoring device such as a computer that communicates with a single modular wireless sensing unit using radio frequency identification (RFID) or using an RFID reader or a standard wireless radio network interface such as 802.11. The wireless sensing unit incorporates an RFID tag for communicating using passive or active RFID. Because the RFID tag and other electronics used by the tile have low power requirements, the tile can be wirelessly powered, for example by a built-in piezoelectric power unit to harvest energy from foot traffic or by using magnetic resonance to harvest power from a wireless power source. Data acquisition circuitry built into each tile collects and saves data for transmission to the surface pressure monitoring device. The wireless sensing system can enable a variety of software applications, including fall detection and prediction, gesture input, intrusion detection, and user location tracking to enable smart home automation.

[0009] By placing a plurality of modular wireless sensing devices such as wireless smart floor tiles within a surface area such as a floor area, the system can acquire and measure the pressure field exerted on the surface by people or objects. Instead of optical images, the surface generates a 2D pressure map of "pressure images" where each "pixel" corresponds to a spatial portion of the surface (also referred to herein as a "pressure location") and the "pixel value" is related to the amount of pressure exerted on top of it. The surface images can be analyzed using traditional computer vision and pattern recognition techniques to detect people and their behavior. The system can enable a range of applications including entertainment, surveillance, multimedia content access, and medical rehabilitation.

[0010] The embodiments described herein can present one or more advantages over existing methods. By using independent sensing units, such as modular tiles, when one unit fails or becomes inoperative, the rest of the surface remains operational, and the failed tile can be easily identified and repaired or replaced as needed. By eliminating the need for power and data wires, wireless sensing units, such as wireless tiles, can be installed anywhere without the need to tear up adjacent flooring or other surface coverings to wire cables, and without the risk of failure due to cable damage. By using low-power RFID and other low-power components, the power consumption of the units is minimized, thereby reducing costs and extending the life of the components. RFID tags, particularly passive RFID tags, are very inexpensive, thereby reducing the cost of installation for large surface areas. By using dedicated data acquisition circuitry within each tile, the analog-to-digital conversion and filtering or other preprocessing of sensor data is done in a distributed manner, while enabling the size of the surface to be scaled up without causing data collection or processing bottlenecks on the surface pressure monitoring device due to exponential growth in complexity, cost, and difficulty of data collection and processing as the surface area is increased. Other advantages will be readily apparent based on the following detailed description of exemplary embodiments.

[0011] As used herein, the term "radio frequency identification tag" or "RFID tag" refers to a transponder that is used to transmit digital data in response to an electromagnetic interrogation pulse from an RFID reader device. RFID tags include active configurations, passive configurations, and semi-passive configurations; passive RFID tags typically do not require their own power source, but instead use the energy from the interrogation radio waves from the reader to transmit data back to the reader, while active RFID tags and semi-passive RFID tags typically include or rely on a power source to transmit data.

[0012] As used herein, the term "RFID reader" can refer to a dedicated RFID reader device, or a radio-based communication module of a radio-enabled device, such as a computer or smart phone, that supports 802.11-based or Bluetooth-based wireless communication. TMRFID tags can operate in any of several frequency bands (also referred to herein as "RFID signal frequency bands"): a low-frequency (LF) band, such as 120 kHz to 150 kHz; a high-frequency (HF) band, such as 13.56 MHz; an ultra-high frequency (UHF) band, such as 433 MHz, 865 MHz to 868 MHz, or 902 MHz to 928 MHz; or a microwave band, such as 2450 MHz to 5800 MHz or 3.1 GHz to 10 GHz.

[0013] As used herein, the term "wireless sensing unit" refers to a pressure sensing device that contains electronic hardware capable of collecting and transmitting pressure data without the need for wires, cables, or other conduits to transmit data or power to or from the tile. A "wireless smart floor tile" is an example of a "wireless sensing unit," and exemplary embodiments of a wireless sensing unit can be described herein as a wireless smart floor tile. Unless otherwise noted, the term "tile" is used herein to apply to a wireless smart floor tile.

[0014] As used herein, the term "data acquisition circuit" refers to an electronic component or collection of electronic components used to receive, collect, or acquire data. Exemplary data acquisition circuits are described below with reference to various embodiments.

[0015] As used herein, the term "electrically conductive layer" refers to a layer of a floor tile at least a portion of which is electrically conductive.

[0016] As used herein, the term "power storage device" refers to a device used to store electrical power or energy, such as a battery or a capacitor.

[0017] As used herein, the term "wireless power unit" refers to a component of a wireless smart floor tile that provides power to one or more other components of the tile without receiving power from a cable, wire, or other conduit. Examples of wireless power units described herein include components used to generate electrical energy within the tile (such as using a piezoelectric body) or components used to receive wirelessly transmitted energy (such as using magnetic resonance). The latter type of component can be referred to herein as a "remote power receiver unit."

[0018] As used herein, the term "floor surface" refers to the upper surface of a floor tile that is intended to directly engage with the soles of a person's feet or other objects placed on the floor (such as furniture legs).

[0019] In some aspects, the disclosure describes a wireless sensing unit comprising: a pressure sensor to detect a pressure applied to each of one or more locations on a surface of the wireless sensing unit; a data acquisition circuit to generate digital pressure data based on the pressure detected by the pressure sensor at each of the one or more locations; a radio-frequency identification (RFID) tag to transmit the digital pressure data.

[0020] In some aspects, the disclosure describes a pressure monitoring device comprising: an RFID communication interface to obtain digital pressure data from an RFID reader; a memory having stored thereon sensing unit location data indicative of one or more sensing unit locations; a processor to execute instructions that cause the pressure monitoring device to determine, based on the digital pressure data and the sensing unit location data, a pressure level at each of one or more pressure locations.

[0021] In some aspects, the disclosure describes a method for obtaining pressure data related to one or more pressure locations of a surface area, the method comprising: for each of one or more wireless sensing units located at one or more sensing unit locations within the surface area: detecting, using a pressure sensor of the wireless sensing device, a pressure applied to each of one or more locations on a surface of the wireless sensing device; generating, using a data acquisition circuit of the wireless sensing device, digital pressure data based on the pressure detected by the pressure sensor at each of the one or more locations; transmitting, using a radio-frequency identification (RFID) tag of the wireless sensing device, the digital pressure data to an RFID reader.

[0022] In some examples, the RFID tag transmits the pressure data under an ultra-high frequency (UHF) RFID signal frequency band.

[0023] In some examples, the pressure sensor comprises: a first conductive layer; an electrically sensitive layer that exhibits a change in its electrical property in response to compression; a second conductive layer.

[0024] In some examples, the electrically sensitive layer comprises a capacitively sensitive material, and the electrical property comprises a capacitance.

[0025] In some examples, the electrically sensitive layer comprises a resistively sensitive material, and the electrical property comprises a resistance.

[0026] In some examples, the wireless sensing unit further comprises a power storage device for providing power to one or more components selected from the list of the pressure sensor, the data acquisition circuit, and the RFID tag.

[0027] In some examples, the wireless sensing unit further comprises a wireless power unit for wirelessly charging the power storage device.

[0028] In some examples, the wireless power unit comprises a piezoelectric power generation unit for harvesting kinetic energy from an object exerting a force to the wireless sensing unit.

[0029] In some examples, the wireless power unit comprises a remote power receiver unit for receiving power from a wireless power source using magnetic resonance.

[0030] In some examples, the RFID tag is a passive RFID tag.

[0031] In some examples, the wireless sensing unit comprises a wireless tile.

[0032] In some examples, the pressure sensor is for detecting pressure from a regular tile positioned above the wireless sensing unit.

[0033] In some examples, the wireless sensing unit further comprises a floor surface positioned above the pressure sensor.

[0034] In some examples, the pressure monitoring device further comprises the RFID reader, wherein the RFID reader is for obtaining the digital pressure data from one or more RFID tags.

[0035] In some examples, the RFID communication interface comprises a wireless network interface; the RFID reader comprises a wireless radio antenna.

[0036] In some examples, the method further comprises determining a pressure level at each of the one or more pressure locations based on the digital pressure data and the one or more sensing unit locations.

[0037] In some examples, the RFID tag of each wireless sensing device is a passive RFID tag; the RFID reader is for transmitting an interrogator RFID signal to each RFID tag; each RFID tag is for transmitting the digital pressure data to the RFID reader in response to receiving the interrogator RFID signal from the RFID reader.

[0038] In some examples, the method also includes using a wireless power unit to power each wireless sensing unit.

[0039] In some aspects, the present invention describes a processor-readable medium on which instructions are tangibly stored. When executed by the processor device, the instructions cause the processor device to perform the method steps described above. Attached Figure Description

[0040] The exemplary embodiments of this application will now be illustrated by way of example in the accompanying drawings, in which:

[0041] Figure 1 This is a block diagram of a wireless sensing system for obtaining pressure data associated with multiple pressure locations in a floor area, as provided in the embodiments described herein.

[0042] Figure 2A yes Figure 1 A block diagram of an exemplary wireless sensing unit for a wireless sensing system.

[0043] Figure 2B yes Figure 2A A block diagram of an exemplary capacitive pressure sensor for a wireless sensing unit.

[0044] Figure 2C yes Figure 2A A block diagram of an exemplary resistance-sensitive pressure sensor for a wireless sensing unit.

[0045] Figure 2D yes Figure 2A A simplified side cross-sectional view of a first exemplary configuration of a wireless sensing unit.

[0046] Figure 2E yes Figure 2A A simplified side cross-sectional view of a second exemplary configuration of the wireless sensing unit.

[0047] Figure 3 yes Figure 1 A block diagram of an exemplary pressure monitoring device for a wireless sensing system.

[0048] Figure 4 This is a flowchart of the steps of an exemplary method for obtaining pressure data associated with multiple pressure locations on a surface region, as provided in the embodiments described herein.

[0049] Similar reference numerals can be used to denote similar components in different accompanying drawings. Detailed Implementation

[0050] In various examples, the present disclosure describes wireless sensing units, methods, systems, and processor-readable media for obtaining pressure data related to a plurality of pressure locations of a surface area. Exemplary embodiments of the wireless sensing units can be described herein as wireless smart tiles, which can be used to collect pressure data related to a plurality of pressure locations of a floor area. However, it should be understood that some embodiments can include one or more wireless sensing units that are not used as tiles: for example, a wireless sensing unit can be mounted on a vertical surface (e.g., a wall) for sensing interaction with the vertical surface. Further, some embodiments can use a single wireless sensor unit instead of tiling together multiple wireless sensor units to cover a large surface area: for example, a single wireless sensor unit can be used to provide input to a fitness software application by functioning as a body weight scale and / or a motion mat that measures user balance, center of gravity distribution, body movement, etc.

[0051] In some embodiments, a wireless sensing system (e.g., a smart floor system) includes wireless sensing units (e.g., wireless smart tiles) having RFID tags for communicating with an RFID reader under the ultra-high frequency (UHF) RFID signal band. In some embodiments, the tiles include passive RFID that do not require them to have their own power source. In other embodiments, active RFID tags are used in tiles that are powered by a wireless power unit. Each tile is used to operate independently of other tiles used in a given smart floor system, such that failure of a single tile does not affect the normal operation of the other tiles. In some embodiments, each tile includes its own data acquisition circuit and wireless power unit, thereby enabling the smart floor area to be scaled without reducing performance.

[0052] In some embodiments, a smart floor system can be used to provide input to various software applications. The smart floor system can collect pressure data in a user’s daily life and can be combined with traditional computer vision and pattern recognition techniques to detect the user and their behavior, such as the user’s location, motion patterns, direction, and distance traveled. Using these detected behaviors, the software can perform tasks such as predicting or detecting user falls, monitoring user lifestyle, assisting the user in completing physical rehabilitation tasks, detecting user load and fatigue, etc.

[0053] Exemplary wireless sensing system

[0054] Figure 1This is a block diagram of a wireless sensing system for collecting pressure data associated with multiple pressure locations on a surface area (shown as floor area 114), shown as a smart floor system 100. System 100 includes multiple wireless smart floor tiles 102, 104, 106, 108 and an RFID reader 110. Optionally, system 100 may also include a floor pressure monitoring device 300, a wireless power supply 112, and / or a server 130 communicating with the floor pressure monitoring device 300 via a network 120.

[0055] In use, each wireless smart tile 102, 104, 106, 108 is installed at a corresponding sensing unit location (shown as tile locations 122, 124, 126, 128) in the floor area 114. Each tile location 122, 124, 126, 128 is known to a device (e.g., floor pressure monitoring device 300) that receives floor pressure data from the RFID reader 110, such that the pressure data received from each wireless smart tile 102, 104, 106, 108 can be mapped to a 2D pressure map of the floor area 114. In some embodiments, tile locations 122, 124, 126, 128 are represented by sensing device location data (shown as tile location data 350) stored in the memory of the floor pressure monitoring device 300, as referenced below. Figure 3 As described. Brick location data 350 can be generated manually by the person installing the bricks or through an automated process. For example, in some embodiments, known distance or position sensing technologies, such as laser or infrared ranging or radio frequency triangulation, can be used to automatically measure or determine the brick location. In some embodiments, an RFID reader 110, a floor pressure monitoring device 300, and / or another radio-enabled device can be used to automatically determine the location of each brick using signals transmitted by the RFID tag on each brick.

[0056] The following is combined with Figures 2A to 2E A detailed description of the exemplary wireless smart floor tile 102.

[0057] In some embodiments, RFID reader 110 is a dedicated RFID reader device, such as a fixed or mobile RFID reader. In other embodiments, RFID reader 110 is a radio-based communication module of a radio-enabled device, such as an 802.11-based or Bluetooth-based module of a computer or smartphone. TM The network interface. While passive RFID tags typically require dedicated RFID reader equipment to function properly, some active RFID tags can also transmit data directly to other radio-enabled devices.

[0058] Accordingly, the smart floor system 100 using tiles with active RFID tags can use the existing wireless network interface of the floor pressure monitoring device 300 as the RFID reader 110, as described below with reference to Figure 3 The floor pressure monitoring device 300 can be installed or operated anywhere within the transmission range of the active RFID tags of the tiles, which can be up to about 100 meters in embodiments using active UHF RFID tags.

[0059] The smart floor system 100 using tiles with passive RFID tags can use a dedicated RFID reader 110, which in turn can communicate with the floor pressure monitoring device 300 through the network interface or input / output interface of the floor pressure monitoring device 300. The dedicated RFID reader 110 can be an RFID reader for transmitting interrogator RFID signals to each RFID tag. In some examples, the smart floor system 100 using tiles with passive RFID tags can include a dedicated RFID reader 110 for attachment to a piece of furniture or appliance (e.g., a ceiling light fixture) located above or in the same environment (e.g., the same room) as the floor area 114. By installing the RFID reader 110 in a location close to the floor area 114, the RFID reader 110 can more efficiently interrogate the passive RFID tags of the tiles, thereby facilitating the transmission of data from the tiles to the RFID reader 110. The effective range of passive UHF RFID tags can be about 12 meters.

[0060] The following references are described below with reference to Figure 3 An example floor pressure monitoring device 300 is described in more detail.

[0061] Some embodiments can include a wireless power source 112 for transmitting power to the remote power receiver unit of each tile using magnetic resonance. Transmitting power using magnetic resonance can include resonant inductive coupling or magnetic near-field coupling, such as WiTricity TM Wireless power transmission technology developed by WiTricity Corporation. The wireless power source 112 can include a transmitter coil in communication with a power source (e.g., the electrical system of a building), and the remote power receiver unit of each tile can include a receiver coil that pairs with the transmitter coil of the wireless power source 112.

[0062] In some embodiments, the server 130 can be used to perform advanced software applications using the pressure data collected from the tiles 102, 104, 106, 108. The server 130 can be a mobile electronic device, a desktop computer, an internet server, a distributed cloud computing platform, or any other suitable computing platform. In some embodiments, the server 130 communicates with the floor pressure monitoring device 300 over the network 120. The network 120 can be a local area network (LAN), a wide area network (WAN) such as the Internet, a wireless mesh network, or any other combination of wired and / or wireless communication links that enable communication between electronic devices. In other embodiments, the functionality of the server 130 can be performed by the floor pressure monitoring device 300 itself.

[0063] Various software applications can be able to use the digital pressure data collected from the smart floor system 100, alone or in combination with other input data. The server 130 and / or the floor pressure monitoring device 300 can execute various instructions on their respective processors to implement software applications such as virtual reality (VR), augmented reality (AR), multimedia playback, fitness tracking, physical rehabilitation assistance, health monitoring, and smart home automation, among others, with the digital pressure data. For example, a VR or AR application can use the digital pressure data to determine the position and orientation of a user’s feet. A health or fitness application can use the digital pressure data to determine a user’s weight, posture, and / or physical activity being performed. A health or rehabilitation application can monitor the digital pressure data to predict or detect a fall, alert the user if the user’s current behavior indicates a risk of falling, and alert emergency services or personal care staff if a fall occurs. Some software applications can use the distribution of a user’s weight over time to detect the user’s physical movements, which can enable the application to detect gestures performed using the user’s body parts; these gestures can be used as input for any software application, for example, acting as a switch or remote control.

[0064] In a first example, the floor pressure monitoring device 300 can construct a pressure map of the floor area 114 based on the digital pressure data, and the server 130 can use the pressure map to track the user’s motion, path, and current location over the floor area 114. For example, the distance traveled by the user and an estimated level of user fatigue can be calculated based on the user’s location information over time. A smart home system (e.g., lighting, air conditioning, ventilation) can be controlled based on the user’s current location (e.g., turn on the lights and increase ventilation when the user enters a room, and turn off the lights or decrease ventilation when the user leaves the room).

[0065] In a second example, all or part of the floor area 114 can be designated as a forbidden zone by an intrusion detection software application running on the server 130. An alarm can be triggered when a person is detected entering the forbidden zone based on the digital pressure data. In some examples, a pressure profile pattern of authorized persons (e.g. household residents) can be identified based on user profiles, and detection of a user with an unrecognized pressure profile entering the forbidden zone would be treated as an intrusion event and trigger an alarm.

[0066] Exemplary wireless sensing unit

[0067] Figure 2A is a block diagram of an exemplary wireless sensing unit, shown as Figure 1 a smart tile 102 of the smart floor system 100 of FIG. 1. The four layers 202, 204, 206, 208 of the tile are shown arranged from top to bottom. In some embodiments, Figure 2A The relative positions of these four layers in FIG. 2 can correspond to their relative positions in a side cross-sectional view of the tile 102. The first layer (i.e. the topmost layer) is an RFID tag 202. The RFID tag 202 includes one or more electrical components or circuits, including an RFID receiver circuit and an RFID transmitter circuit. In some embodiments, the RFID tag 202 also includes electronic components for processing and / or storing received data and / or data to be transmitted. In some embodiments, some or all of the processing and / or storage functions can be performed by the data acquisition circuit 210 described below.

[0068] In some embodiments, the RFID tag 202 is used to communicate in the UHF RFID signal frequency band (e.g. 433 MHz, 865-868 MHz, or 902-928 MHz). In some embodiments, lower RFID frequencies (e.g. HF or LF bands) can be used, but can result in an RFID reader 110 having a shorter read range and / or slower data read rates. Various inexpensive UHF RFID chipsets are currently available on the market that have ultra-low power consumption features that make them suitable for incorporation into various embodiments described herein. In addition, many UHF RFID product manufacturers have found ways to design tags, antennas, and readers that maintain high performance even in difficult environments (e.g. high interference environments). Passive UHF RFID tags also tend to be easier to manufacture and less expensive than LF and HF RFID tags. Thus, use of UHF RFID tags can provide several advantages compared to alternative solutions.

[0069] The second and fourth layers of the tile 102 collectively make up a pressure sensor 200. An exemplary pressure sensor 200 is described in more detail below with reference to Figure 2B An alternative pressure sensor 240 is described in more detail below with reference to Figure 2CDescribed in more detail.

[0070] The tile 102 includes a data acquisition circuit 210 for acquiring sensor data from the pressure sensor 200, performing processing operations on the sensor data, and providing the processed data to the RFID tag 202. In some embodiments, the data acquisition circuit 210 can be an integrated circuit (IC). In some examples, the data acquisition circuit 210 can also function as a power management unit to receive power from a power source and in turn supply power to one or more components of the wireless smart floor tile 102. In some examples, the data acquisition circuit 210 actively sends a signal to or through the pressure sensor 200 to obtain pressure sensor output collected by the data acquisition circuit 210. In some examples, the data acquisition circuit 210 includes an analog-to-digital converter (ADC) to convert acquired analog pressure sensor 200 data (i.e., output of the pressure sensor 200) to digital pressure data, which is provided to the RFID tag 202 of the wireless smart floor tile 102. In some examples, the digital pressure data can be further processed or filtered by the data acquisition circuit 210 before being provided to the RFID tag 202. In some embodiments, the electronic components of two or more of the RFID tag 202, the pressure sensor 200, and / or the data acquisition circuit 210 can be combined in a single electronic component or circuit.

[0071] The second layer of the tile 102 is a receiving layer 204 used by the data acquisition circuit 210 to receive pressure sensor output. The fourth layer of the tile 102 is a transmitting layer 208 used by the data acquisition circuit 210 to send a signal through the pressure sensor 200 to obtain pressure sensor output. The third layer of the tile 102 is a sensing layer 206 that includes an electrically sensitive layer that exhibits changes in its electrical properties in response to compression. The signal sent through the transmitting layer 208 produces a pressure sensor output at the receiving layer 204, the properties of which are determined by the compression profile and amplitude of the sensing layer 206 portion. Thus, the data acquisition circuit 210 generates a signal (e.g., a pulse) on a pin of the transmitting layer 208 and collects the resulting feedback signal from a pin of the receiving layer 204. The feedback signal values of the pin of the receiving layer 204 can be processed to determine the pressure level at each of a plurality of locations of the tile 102. Reference is made to the following description of the sensing layer 206 for further details. Figures 2B to 2C The structure and operation of example pressure sensors 200, 240 are described in more detail.

[0072] Brick 102 may optionally include a power management unit 216, which may include a wireless power unit 212 and / or a power storage device 214. Power management unit 216 may include electronic logic components to manage power harvesting and supply to power one or more electronic components of brick 102. In some embodiments, the power management functions of power management unit 216 may be performed by data acquisition circuitry 210.

[0073] In some embodiments, the power storage device 214 is a battery. In other embodiments, the power storage device 214 includes a supercapacitor for storing electricity and a buck-boost circuit for converting the voltage of the supercapacitor into a constant output voltage. In some embodiments, the output voltage of the power storage device 214 may be approximately 3.3V or 1.8V. The power storage device 214 may be used to supply power to one or more components of the brick 102: RFID tag 202 (if it is an active RFID tag), data acquisition circuitry 210, and / or pressure sensor 200.

[0074] In some embodiments, the wireless power unit 212 is included in the power management unit 216. The wireless power unit 212 can harvest electrical energy from internal or external sources. The harvested power can be supplied to the power management unit 216 to charge the power storage device 214 or to directly power one or more components of the brick 102.

[0075] In some embodiments, as referenced above Figure 1 As described in the wireless power supply 112 of the smart floor system 100, the wireless power unit 212 may include a remote power receiver unit for receiving power transmitted from the wireless power supply 112, for example, using magnetic resonance. The remote power receiver unit may include a receiver coil paired with a transmitter coil of the wireless power supply 112.

[0076] In some embodiments, the wireless power unit 212 may include a piezoelectric power generation unit for harvesting kinetic energy from an object that applies force to the wireless smart tile 102. Piezoelectric technology generates electrical energy when a piezoelectric crystal is compressed. Kinetic energy from a foot or other object compressing the tile 102 (e.g., the compression sensing layer 206, as described below) can be used to compress the piezoelectric crystal, thereby generating a charge that can be used to charge the power storage device 214.

[0077] Figure 2B yes Figure 2A A block diagram of an exemplary capacitive pressure sensor 200 for a wireless smart tile 102. See above reference. Figure 2AAs described, pressure sensor 200 is composed of three layers: a transmitting layer 208, a sensing layer 206, and a receiving layer 204. In this example, transmitting layer 208 is composed of a plurality of electrically conductive strips that act as electrical signal channels (e.g., first transmitting layer channel 226 and second transmitting layer channel 228). Each transmitting layer channel receives a transmitting layer input signal 238 from data acquisition circuit 210. Sensing layer 206 is a layer of electrically sensitive material, such as a dielectric material, that exhibits changes in its electrical properties in response to compression. In some embodiments, the material is a capacitively sensitive material that exhibits changes in its capacitance in response to compression. In other embodiments, the material is a resistively sensitive material that exhibits changes in its resistance in response to compression. In this example, receiving layer 204 is composed of a plurality of electrically conductive strips that act as electrical signal channels (e.g., first receiving layer channel 222 and second receiving layer channel 224). Each receiving layer channel provides a receiving layer output signal 236 to data acquisition circuit 210.

[0078] The channels of receiving layer 204 are oriented orthogonally to the channels of transmitting layer 208. Thus, the portion of sensing layer 206 that occupies each area of overlap of a receiving layer channel and a transmitting layer channel effectively acts to complete a circuit between the receiving layer channel and the transmitting layer channel, the capacitance of which is determined by the amount of compression applied to that portion of sensing layer 206. For example, the material of sensing layer 206 located at the area of overlap of first receiving layer channel 222 and first transmitting layer channel 226 acts as a first capacitor 232 completing a circuit between first receiving layer channel 222 and first transmitting layer channel 226, where the capacitance of first capacitor 232 varies depending on the amount of force or compression applied to that portion of transmitting layer 206, for example, by a human foot or other object placed on that portion of the top surface of tile 102. Similarly, the material of sensing layer 206 located at the area of overlap of second receiving layer channel 224 and second transmitting layer channel 228 acts as a second capacitor 234 completing a circuit between second receiving layer channel 224 and second transmitting layer channel 228, where the capacitance of second capacitor 234 varies depending on the amount of force or compression applied to that portion of tile 102.

[0079] Accordingly, the data acquisition circuit 210 can determine the force or amount of compression applied to each of the plurality of locations of the tile 102 based on the capacitance present in the circuit formed by any transmitting layer channel and receiving layer channel pair. For example, when a transmitting layer input signal 238 (e.g., a pulse) is provided to the first transmitting layer channel 226, the capacitance of the first capacitor 232 influences the signal response of the first receiving layer channel 222 detected by the data acquisition circuit 210 through the receiving layer output signal 236 of the first receiving layer channel 222, and can be converted by the data acquisition circuit 210 into a digital signal representative of the force or amount of compression of the sensing layer 206 at the corresponding portion of the tile 210. The data acquisition circuit 210 can aggregate the digital representation of the force or compression applied to each location of the tile 102 (corresponding to the overlap of the receiving channels and transmitting channels) to form a two-dimensional pressure map. This 2D pressure map can be provided by the data acquisition circuit 210 to the RFID tag 202 as digital pressure data.

[0080] In one example embodiment, the data acquisition circuit 210 generates digital pressure data by transmitting a series of signal pulses through the transmitting channels. First, a signal pulse (i.e., transmitting channel input signal 238) is transmitted through the first transmitting channel (i.e., first transmitting layer channel 226), and a corresponding receiving channel output signal 236 is recorded by the data acquisition circuit from each receiving channel. This first set of receiving channel output signals 236 indicates the capacitance of each receiving channel for each overlap with the first transmitting layer channel 226. This process is then repeated for each additional transmitting channel. By rapidly cycling through the transmitting channels, digital pressure data for each transmitting channel can be generated in an order that indicates the overlap of the current transmitting channel with each receiving channel. It should be appreciated that other sampling techniques can be used to sample the pressure sensor data to generate a two-dimensional grid of digital pressure data corresponding to a 2D grid of channel overlap areas.

[0081] In other embodiments, different shapes of conductive material can be used to form one or more receiving channels and / or transmitting channels.

[0082] In some embodiments, the digital pressure data generated by the data acquisition circuit 210 based on the receiving layer output signals 236 can include different data from the digital 2D pressure map.

[0083] Figure 2C is an example resistive sensitive pressure sensor 240 for a wireless smart floor tile, e.g., to replace Figure 2A the capacitive sensitive pressure sensor 200 of the wireless smart floor tile 102 of Figure 2BThe capacitive pressure sensor 200 in FIG. 2B is identical to the capacitive pressure sensor 200 in FIG. 2A, with the exception that the sensing layer 206 is composed of a resistive sensing material. Thus, each portion of the sensing layer 206 that occupies each overlapping region of the receiving layer channel and the transmitting layer channel effectively serves to complete a circuit between the receiving layer channel and the transmitting layer channel, the amount of resistance being determined by the amount of compression applied to that portion of the sensing layer 206. The material of the sensing layer 206 located at the overlapping region of the first receiving layer channel 222 and the first transmitting layer channel 226 acts as a first resistor 242 completing a circuit between the first receiving layer channel 222 and the first transmitting layer channel 226, where the resistance of the first resistor 242 varies depending on the amount of force or compression applied to that portion of the transmitting layer 206, for example, by a human foot or other object placed on that portion of the top surface of the tile 102. Similarly, the material of the sensing layer 206 located at the overlapping region of the second receiving layer channel 224 and the second transmitting layer channel 228 acts as a second resistor 244 completing a circuit between the second receiving layer channel 224 and the second transmitting layer channel 228, the resistance varying with the amount of force or compression applied to that portion of the tile 102.

[0084] It will be appreciated that the overlapping region between each receiving channel and each transmitting channel acts as a capacitor (in Figure 2B ) or a resistor (in Figure 2C ), thereby enabling the pressure at each such region of the tile 102 to be monitored. Figure 2B and Figure 2C Only two such regions are shown in FIGS. 2A and 2B to avoid visual clutter. Similarly, for simplicity and visibility, the number of channels shown in FIGS. 2A and 2B is small; in some embodiments, the number of channels in each layer 204, 208 can be greater than or less than the number shown. Figures 2B to 2C

[0085] Figures 2D to 2E Two alternative configurations 250, 260 for a wireless smart floor tile 102 to be placed on a floor 254 are shown in FIGS. 2C and 2D.

[0086] Figure 2D ​is a simplified side cross-sectional view of a first exemplary configuration 250 of wireless smart floor tiles 102 on a floor 254. The floor 254 is a base that can have tiles or other flooring installed on top of it, such as a concrete or plywood surface underneath finished flooring. In the first configuration 250, the wireless smart floor tiles 102 are used to be installed underneath conventional tiles 252, conventional flooring, or other non-smart flooring components. In the first configuration 250, the wireless smart floor tiles 102 detect pressure based on forces or pressure transmitted through the conventional tiles 252. Thus, a user stepping on top of the conventional tiles 252 will compress the portion of the wireless smart floor tiles 102 directly underneath where the user's foot contacts the conventional tiles 252, with the spread of the pressure varying based on the physical properties of the conventional tiles 252 (e.g., thickness, stiffness, tensile strength, elasticity). Generally, if the conventional tiles 252 are relatively thin, flexible, and elastic, the sensitivity of the pressure sensor 200 can be improved in this first configuration 250.

[0087] Figure 2E is a simplified side cross-sectional view of a second exemplary configuration 260 of wireless smart floor tiles 102 on a floor 254. In the second configuration 260, the wireless smart floor tiles 102 include a floor surface 262 that is positioned above the pressure sensor 200, which is intended to act as the top layer of flooring for the floor area 114. Thus, the components of the wireless smart floor tiles 102 are built into tiles or flooring that are intended to be installed and used as the top layer of flooring.

[0088] The first configuration 250 and the second configuration 260 can each have advantages. The first configuration 250 can enable users to be more flexible in using pre-existing flooring products or selecting from a wide range of conventional flooring products, as the wireless smart floor tiles 102 are essentially an add-on to conventional flooring installation. Individual wireless smart floor tiles 102 can also be replaced as needed without discarding the entire finished tile, which can reduce the long-term cost of the system 100. On the other hand, the second configuration 260 can enable the selection of a floor surface 262 to maximize the sensitivity of the pressure sensor 200. The second configuration 260 can also simplify the process of installing and replacing the smart flooring system 100 or individual wireless smart floor tiles 102, as only a single layer of flooring needs to be installed or removed.

[0089] Exemplary floor pressure monitoring device

[0090] Figure 3 is a block diagram of an exemplary floor pressure monitoring device 300 suitable for performing examples described herein, such as a computer, a cloud computing platform, or a mobile electronic device. Other examples suitable for implementing the embodiments described in this disclosure can be used, which can include different components than those described below. Although Figure 3A single instance of each component is shown, but multiple instances of each component in the floor pressure monitoring device 300 can exist.

[0091] The floor pressure monitoring device 300 can include one or more processors 325, such as a central processing unit (CPU), a graphics processing unit (GPU), a microprocessor, a digital signal processor, an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), a special-purpose logic circuit, a special-purpose artificial intelligence processing unit, or a combination thereof. The floor pressure monitoring device 300 can also include one or more optional input / output (I / O) interfaces 332, which can enable connection with one or more optional input devices 334 and / or optional output devices 336.

[0092] In the illustrated example, one or more input devices 334 (e.g., a maintenance console, a keyboard, a mouse, a microphone, a touchscreen, and / or a keypad) and one or more output devices 336 (e.g., a maintenance console, a display, a speaker, and / or a printer) are shown as optional and external to the floor pressure monitoring device 300. In other examples, any one or more input devices 334 and one or more output devices 336 can not exist, in which case the one or more I / O interfaces 332 can not be needed.

[0093] The floor pressure monitoring device 300 can include one or more network interfaces 322 to communicate wired or wirelessly with one or more devices or systems of a network (e.g., the network 120). The one or more network interfaces 322 can include wired links (e.g., Ethernet cables) and / or wireless links (e.g., one or more antennas) for intranet and / or Internet communications using network addressable protocols such as the Transmission Control Protocol / Internet Protocol (TCP / IP). One or more of the network interfaces 322 can be used to receive digital pressure data from the RFID readers 110. In some embodiments, the RFID readers 110 can communicate directly or indirectly with the floor pressure monitoring device 300 through other means (e.g., the I / O interfaces 332). In some embodiments using wireless smart tiles 102 with active RFID tags, the wireless radio antenna (e.g., an 802.11 antenna or a Bluetooth antenna) can be used to receive digital pressure data from the RFID readers 110. TMThe antenna) can be included as part of one of the wireless network interfaces 322 to function as an RFID reader without using a dedicated external RFID reader 110. In each of these configurations, the interface element (e.g., network interface 322 or I / O interface 332) used to communicate with or function as an RFID reader can be referred to as an “RFID communication interface.”

[0094] The floor pressure monitoring device 300 can also include one or more storage units 324, which can include solid state drives, hard disk drives, disk drives, and / or optical disk drives, among other mass storage units.

[0095] The floor pressure monitoring device 300 can include one or more memories 328, which can include volatile or non-volatile memories (e.g., flash memories, random access memories (RAMs), and / or read-only memories (ROMs)). The one or more non-transitory memories 328 can store instructions executed by the one or more processor devices 325, for example, to perform examples described in this disclosure. The one or more memories 328 can include software instructions 338, for example, to implement an operating system and other applications / functions.

[0096] The one or more memories 328 can also store tile location data 350, which can be collected or generated as described above with reference to FIG. 2 when each wireless smart floor tile 102, 104, 106, 108 is installed at a respective tile location 122, 124, 126, 128 of the floor area 114. Figure 1 The one or more memories 328 can also store digital pressure data 360 received from the RFID reader 110 and / or directly from the tiles 102. The stored digital pressure data 360 can include digital pressure data samples received over time to enable software applications, for example, to track movement of a person over the floor area 114.

[0097] The one or more memories 328 can also store digital pressure data 360 received from the RFID reader 110 and / or directly from the tiles 102. The stored digital pressure data 360 can include digital pressure data samples received over time to enable software applications, for example, to track movement of a person over the floor area 114.

[0098] In some examples, the floor pressure monitoring device 300 can additionally or alternatively execute instructions from an external memory (e.g., an external drive in wired or wireless communication with the floor pressure monitoring device 300), or can be provided with executable instructions by a transitory or non-transitory computer readable medium. Examples of non-transitory computer readable media include RAM, ROM, erasable programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), flash memory, CD-ROM, or other portable memory.

[0099] The floor pressure monitoring device 300 can also include a bus 342 that provides communication amongst the components of the floor pressure monitoring device 300, including those discussed above. The bus 342 can be any suitable bus architecture, including for example a memory bus, a peripheral bus, or a video bus.

[0100] It will be appreciated that, in some embodiments, the various components and operations described herein can be implemented on a plurality of separate devices or systems.

[0101] Example method for obtaining floor pressure data

[0102] Figure 4 An example method 400 for obtaining pressure data related to a plurality of pressure locations of a floor area is shown. In some embodiments, the method 400 can be performed using components of the smart floor system 100, as described below, although it will be appreciated that the various steps of the method 400 can also be performed by variants of the described devices and systems.

[0103] The method can optionally begin at step 401. At 401, the wireless power unit 212 is used to power each wireless smart floor tile 102. The wireless power unit 212 can provide the power required by the data acquisition circuit 210 to collect the receive layer output signals 236 from the pressure sensor 200 and generate digital pressure data, either directly or through the power storage device 214, as described above with reference to Figure 2B .

[0104] At 402, the pressure sensor 200 detects the pressure applied to each of a plurality of locations on the surface of the wireless smart floor tile 102, as described above with reference to Figure 2B . The characteristics of the receive layer output signals 236 generated in response to the transmit layer input signals 238 from the data acquisition circuit 210 are determined by the pressure on each area of the sensing layer 206 corresponding to the overlap of the receive channel and the transmit channel.

[0105] At 404, the data acquisition circuit 210 generates digital pressure data based on the pressure detected at each location of the tile 102. The characteristics of the received layer output signal 236 generated in response to the transmitted layer input signal 238 from the data acquisition circuit 210 can be used by the data acquisition circuit 210 to generate a 2D grid of digital pressure data, as described above with reference to Figure 2B

[0106] Optionally, at step 406, the tile 102 receives an interrogator RFID signal from the RFID reader 110. This step 406 can be necessary in embodiments that use a passive RFID tag in the tile 102, while this step 406 can be optional in embodiments that use an active RFID tag. Some embodiments that use an active RFID tag can transmit the digital pressure data to the RFID reader 110 on a regular schedule or in response to detecting a change in the predetermined magnitude of the pressure detected at one or more locations of the tile 102. Other embodiments that use an active RFID tag can transmit the digital pressure data only in response to an interrogation by the RFID reader 110.

[0107] At 408, the RFID tag 202 of the tile 102 is used to transmit the digital pressure data to the RFID reader 110. As described above with reference to Figure 1 and Figure 3 In some embodiments that use an active RFID tag, the RFID reader 110 can be a network interface of the floor pressure monitoring device 300.

[0108] After step 408, the method 400 can return to step 401 or 402 for each additional wireless smart floor tile 104, 106, 108 of the smart floor system 100. It will be appreciated that each tile 102, 104, 106, 108 can execute steps 401-408 of the method 400 in parallel.

[0109] At 410, the floor pressure monitoring device 300 or the server 130 determines a pressure level at each location of the tile 102 based on the digital pressure data and the plurality of tile locations 122, 124, 126, 128. As described above with reference to Figure 3 The plurality of tile locations 122, 124, 126, 128 can be stored in the memory 328 of the floor pressure monitoring device 300 as tile location data 350 along with one or more samples of the digital pressure data 360. By mapping the digital pressure data 360 to the tile location data 350, the processor 325 of the floor pressure monitoring device 300 can generate a 2D pressure map of the floor area 114 indicating the pressure level at the plurality of locations of each tile.

[0110] Overview ​

[0111] Although the present application describes methods and processes by steps performed in a particular order, one or more steps of the methods and processes can be omitted or changed, as appropriate. In suitable circumstances, one or more steps can be performed in an order other than that described.

[0112] Although the present application is described, at least in part, in terms of methods, one skilled in the art will readily recognize that the application is also directed to various components for performing at least some of the aspects and features of the methods, whether by hardware, software, or any combination thereof. Accordingly, the technical solutions of the present application can be implemented in the form of a software product. The appropriate software product can be stored in a pre-recorded storage device or other similar non-volatile or non-transitory computer-readable medium, including DVD, CD-ROM, USB flash disk, removable hard disk or other storage medium, etc. The software product includes instructions tangibly stored thereon, which enable a processing device (e.g., a personal computer, a server, or a network device) to perform examples of the methods disclosed herein.

[0113] The present application can be implemented in other specific forms without departing from the subject matter of the claims. The described exemplary embodiments are merely illustrative in all aspects and are not restrictive. Features selected from one or more of the above-described embodiments can be combined to create alternative embodiments not explicitly described, and it is understood that features suitable for such combinations are within the scope of the present application.

[0114] All values and subranges within the disclosed ranges are also disclosed. In addition, although systems, devices, and processes disclosed and shown herein can include particular numbers of elements / components, the systems, devices, and components can be modified to include more or less of such elements / components. For example, although any disclosed element / component can be referred to as a singular number, embodiments disclosed herein can be modified to include a plurality of such elements / components. The subject matter described herein is intended to cover and encompass all appropriate technical alterations.

Claims

1. A wireless sensing system for obtaining pressure data relating to one or more pressure locations of a surface area, characterized in that, Comprising: a plurality of wireless sensing units arranged in an array, each wireless sensing unit being located at a respective sensing unit location within the surface area, and comprising: a pressure sensor for detecting a pressure applied to each of a plurality of locations on a surface of the wireless sensing unit, and comprising: a first electrically conductive layer comprising a plurality of electrically conductive strips; an electrically sensitive layer that exhibits a change in an electrical property in response to compression; the electrically sensitive layer being interposed between the first electrically conductive layer and the second electrically conductive layer; a second electrically conductive layer comprising a plurality of electrically conductive strips; the electrically conductive strips of the first electrically conductive layer being oriented orthogonally to the electrically conductive strips of the second electrically conductive layer, and the electrically conductive strips of the second electrically conductive layer being oriented perpendicularly to the electrically conductive strips of the first electrically conductive layer in a direction normal to the surface of the wireless sensing unit at each of the plurality of locations on the surface of the wireless sensing unit; a data acquisition circuit for generating digital pressure data based on the pressure detected by the pressure sensor at each of the plurality of locations; a radio-frequency identification (RFID) tag for transmitting the digital pressure data to an RFID reader; a power storage device for providing power to the pressure sensor, the data acquisition circuit, and the RFID tag; a wireless power unit for charging the power storage device in a wireless charging manner; and, the wireless power unit comprising a remote power receiver unit for receiving power from a wireless power source using magnetic resonance; a wireless power source for transmitting power to the remote power receiver unit of the wireless power unit of the plurality of wireless sensing units arranged in an array using magnetic resonance.

2. The wireless sensing system of claim 1, wherein, The RFID tag transmits the digital pressure data under an ultra-high frequency (UHF) RFID signal frequency band.

3. The wireless sensing system of claim 1 or 2, wherein, The data acquisition circuit is further for generating digital pressure data by: transmitting a signal pulse to each electrically conductive strip of the first electrically conductive layer; receiving a signal response of the signal pulse from each electrically conductive strip of the second electrically conductive layer; generating the digital pressure data based on the plurality of signal pulses and the plurality of signal responses.

4. The wireless sensing system of claim 3, wherein, The electrically sensitive layer comprises a capacitance-sensitive material, and the electrical property comprises a capacitance.

5. The wireless sensing system of claim 3, wherein, The electrically sensitive layer comprises a resistance-sensitive material, and the electrical property comprises a resistance.

6. The wireless sensing system of claim 1, wherein, The wireless power unit comprises a piezoelectric power generation unit for harvesting kinetic energy from an object applying a force to the wireless sensing unit.

7. The wireless sensing system of claim 1, wherein, The RFID tag is a passive RFID tag.

8. The wireless sensing system of claim 1, wherein, The wireless sensing unit comprises a wireless tile.

9. The wireless sensing system of claim 8, wherein, The pressure sensor is for detecting pressure from a conventional tile located above the wireless sensing unit.

10. The wireless sensing system of claim 8, wherein, Further comprising a floor surface located above the pressure sensor.

11. The wireless sensing system of claim 1, wherein, Further comprising a pressure monitoring device, the pressure monitoring device comprising: a processor; an RFID communication interface communicatively connected to the processor for obtaining digital pressure data from an RFID reader; a memory, in communication connection with the processor, having stored thereon sensing unit location data indicative of a plurality of sensing unit locations; a wireless power source for transmitting power to a wireless sensing unit located at a sensing unit location via magnetic resonance; a processor for executing instructions, the instructions causing the pressure monitoring device to determine a pressure level at each of one or more pressure locations based on the digital pressure data and the sensing unit location data.

12. The wireless sensing system of claim 11, wherein, Further comprising the RFID reader, wherein the RFID reader is for obtaining the digital pressure data from one or more RFID tags.

13. The wireless sensing system of claim 11 or 12, wherein: the RFID communication interface comprises a wireless network interface; the RFID reader comprises a wireless radio antenna.

14. A method for obtaining pressure data relating to one or more pressure locations of a surface area, characterized in that, Further comprising: for each of a plurality of wireless sensing units arranged in an array at a plurality of sensing unit locations within the surface area: receive power from a wireless power source using magnetic resonance; charge a power storage device of the wireless sensing unit using the received power, and use the power storage device to provide power to a pressure sensor, a data acquisition circuit, and an RFID tag of the wireless sensing unit; detect pressure applied to each of one or more locations on a surface of the wireless sensing unit using a pressure sensor of the wireless sensing unit; the pressure sensor comprising: a first electrically conductive layer comprising a plurality of electrically conductive strips; an electrically sensitive layer that exhibits a change in its electrical properties in response to compression; the electrically sensitive layer traversing a space between the first electrically conductive layer and a second electrically conductive layer; a second electrically conductive layer comprising a plurality of electrically conductive strips; the electrically conductive strips of the first electrically conductive layer are oriented orthogonally to the electrically conductive strips of the second electrically conductive layer, and the electrically conductive strips of the second electrically conductive layer and the electrically conductive strips of the first electrically conductive layer have a region of mutual overlap comprising the electrically sensitive layer at each location on the surface of the wireless sensing unit in a direction perpendicular to the surface of the wireless sensing unit; generate digital pressure data based on the pressure detected by the pressure sensor at each of the one or more locations using a data acquisition circuit of the wireless sensing unit; 15. The method of claim 14, wherein, transmit the digital pressure data to an RFID reader using a radio-frequency identification (RFID) tag of the wireless sensing unit. Further comprising determining a pressure level at each of the one or more pressure locations based on the digital pressure data and the one or more sensing unit locations.

16. The method of claim 14 or 15, wherein: the RFID tag of each wireless sensing unit is a passive RFID tag; the RFID reader is for transmitting an interrogator RFID signal to each RFID tag; each RFID tag is for transmitting the digital pressure data to the RFID reader in response to receiving an interrogator RFID signal from the RFID reader.

17. The method of claim 14, wherein, The RFID tag of each of the wireless sensing units transmits the digital pressure data at an ultra-high frequency (UHF) RFID signal band.

18. The method of claim 14, wherein, The data acquisition circuit is further configured to generate digital pressure data by: sending a signal pulse to each conductive strip of the first conductive layer; receiving a signal response of the signal pulse from each conductive strip of the second conductive layer; generating the digital pressure data based on the plurality of signal pulses and the plurality of signal responses.

19. The method of claim 14, wherein, The electrically sensitive layer comprises a capacitance sensitive material, and the electrical property comprises capacitance.

20. The method of claim 14, wherein, The electrically sensitive layer comprises a resistance sensitive material, and the electrical property comprises resistance.

21. A computer program, characterized in that, The computer program comprises instructions which, when executed by a computer, cause the computer to perform the method of any one of claims 14 to 20.

22. A computer readable medium characterized by The computer readable medium comprises instructions which, when executed by a computer, cause the computer to perform the method of any one of claims 14 to 20.

Images