The current subject matter generally relates to data processing, and in particular, determination of location of wireless devices, tags, and/or any other communication devices using ultra-wideband techniques.
A significant number of communications devices operate in today's communications systems. Various wireless communication protocols have been developed for determining location (i.e., localization) of such devices. These include WiFi protocols, satellite-based signaling, long term evolution (LTE) systems protocols, passive radio frequency identification (RFID) methods, active RFID methods, Bluetooth® and other protocols. However, conventional location determination systems are not able to accurately determine location of wireless devices. They also suffer from high latency and consume significant amounts of power.
In some implementations, the current subject matter relates to a computer-implemented method for determining a location of a wireless devices. The method may include configuring one or more second wireless devices in a plurality of second wireless devices for processing one or more communications exchanged with a first wireless device in a plurality of first wireless devices to determine a location of the first wireless device in an environment, processing, using the one or more second wireless devices, the one or more communications, and determining, based on the processed one or more communications, the location of the first wireless device in the environment.
In some implementations, the current subject matter may include one or more of the following optional features. The communications may include at least one of: a received communication, a transmitted communication, and any combination thereof by at least one of: the first wireless device, one or more second wireless devices, and any combination thereof. Further, the communications may include a communication responsive to at least one of: the received communication, the transmitted communication, and any combination thereof. Additionally, the communications may include a signal transmission. Moreover, as stated above, the processing of the communications may include determining, based on the signal transmission, an angle of arrival of the signal transmission, and determining, using the determined angle of arrival of the signal transmission, the location of the first wireless device in the environment.
The signal transmission may be received using one or more second wireless devices in a plurality of second wireless devices. Each second wireless device in the plurality of second wireless devices may include one or more antennas (e.g., antennas may include transceivers) configured to receive the signal transmission from the first wireless device and/or transmit at least another signal to the first wireless device.
In some implementations, each antenna may be configured to be synchronized using at least one clock reference signal. The clock reference signals may be generated using at least one processor of a second wireless device in the plurality of wireless devices receiving the signal transmission.
In some implementations, each antenna may be configured to be positioned a predetermined distance from another antenna in the one or more antennas. Further, each antenna may be configured to be oriented in a predetermined direction.
In some implementations, the antennas of each second wireless device in the plurality of second wireless devices may be configured to be synchronized using at least one of the following parameters: a time, a frequency, a phase, and any combination thereof.
In some implementations, at least one of the first and second wireless devices may be configured to be ultra-wideband wireless devices. The signal transmission may be an ultra-wideband signal transmission. In some implementations, the signal transmission may include a blink transmission.
In some implementations, the determining of the angle of arrival of the signal transmission may include estimating at least one of an azimuth angle of arrival and a polar angle of arrival for each antenna, combining estimated azimuth angles of arrival and polar angles of arrival for one or more antennas, and determining, based on the combined estimates of azimuth angles of arrival and polar angles of arrival for one or more antennas, an actual angle of arrival of the signal transmission.
In some implementations, the determining the actual angle of arrival of the signal transmission may be performed in real-time. The determined location of the first wireless device in the environment may correspond to the location of the first wireless device in a multi-dimensional space at a predetermined point in time.
In some implementations, the first wireless device may include at least one of a stationary first wireless device, a moving wireless device, and any combination thereof.
In some implementations, the determination of the location of the first wireless devices may include determining the location of the first wireless device using a single second wireless device in the plurality of second wireless devices by executing a two-way-ranging communication protocol at one or more antennas of the single second wireless device. Further, the determination of the location of the first wireless device may include determining the location of the first wireless device using at least one of the following: at least one of one or more azimuth angles, one or more polar angles, and any combination thereof associated with the signal transmission received by at least two or more of the second wireless devices in the plurality of second wireless devices; at least one of one or more azimuth angles, one or more polar angles, one or more values resulting from execution of the two-way-ranging communication protocol, and any combination thereof by at least one or more of the second wireless devices in the plurality of second wireless devices; and any combination thereof.
In some implementations, the current subject matter relates to an apparatus (e.g., for determination of a location of a wireless device (e.g., tag)). The apparatus may include one or more antennas configured to be positioned a predetermined distance from at least another antenna in the one or more antennas, one or more transceivers communicatively coupled to one or more antennas, and at least one processing device communicatively coupled to one or more transceivers. The processing devices may be configured to process one or more communications received by one or more transceivers, and determine a location of at least one wireless device in an environment based on one or more processed communications.
In some implementations, the current subject matter may include one or more of the following optional features. One or more communications may include a signal transmission. The processing devices may be configured to determine, based on the signal transmission, an angle of arrival of the signal transmission, and determine, using the determined angle of arrival of the signal transmission, the location of the wireless device in the environment. One or more antennas may be configured to receive the signal transmission from the wireless device and/or transmit at least another signal to the wireless device.
In some implementations, each antenna may be configured to be synchronized using at most one clock reference signal, the clock reference signal being generated by the at least one processing device. Each antenna may be further configured to be oriented in a predetermined direction. One or more antennas may be configured to be synchronized using at least one of the following parameters: a time, a frequency, a phase, and any combination thereof.
In some implementations, the signal transmission is an ultra-wideband signal transmission. Moreover, the signal transmission may include a blink transmission.
In some implementations, at least one processing device may determine the angle of arrival of the signal transmission by estimating at least one of an azimuth angle of arrival and a polar angle of arrival for each antenna, combining estimated azimuth angles of arrival and polar angles of arrival for one or more antennas, and determining, based on the combined estimates of azimuth angles of arrival and polar angles of arrival for one or more antennas, an actual angle of arrival of the signal transmission. Further, the determination of the actual angle of arrival of the signal transmission may be performed in real-time. The determined location of the wireless device in the environment may correspond to the location of the wireless device in a multi-dimensional space at a predetermined point in time.
In some implementations, the wireless device may include at least one of: a stationary wireless device, a moving wireless device, and any combination thereof.
In some implementations, the determination of the location of the wireless device may include executing a two-way-ranging communication protocol at one or more antennas. Further, the determination of the location of the wireless device may include determining the location of the wireless device using at least one of the following: at least one of one or more azimuth angles, one or more polar angles, and any combination thereof associated with the signal transmission; at least one of one or more azimuth angles, one or more polar angles, one or more values resulting from execution of the two-way-ranging communication protocol, and any combination thereof, and any combination thereof.
Implementations of the current subject matter can include, but are not limited to, systems and methods consistent including one or more features are described as well as articles that comprise a tangibly embodied machine-readable medium operable to cause one or more machines (e.g., computers, etc.) to result in operations described herein. Similarly, computer systems are also described that may include one or more processors and one or more memories coupled to the one or more processors. A memory, which can include a computer-readable storage medium, may include, encode, store, or the like one or more programs that cause one or more processors to perform one or more of the operations described herein. Computer implemented methods consistent with one or more implementations of the current subject matter can be implemented by one or more data processors residing in a single computing system or multiple computing systems. Such multiple computing systems can be connected and can exchange data and/or commands or other instructions or the like via one or more connections, including but not limited to a connection over a network (e.g. the Internet, a wireless wide area network, a local area network, a wide area network, a wired network, or the like), via a direct connection between one or more of the multiple computing systems, etc.
The details of one or more variations of the subject matter described herein are set forth in the accompanying drawings and the description below. Other features and advantages of the subject matter described herein will be apparent from the description and drawings, and from the claims. While certain features of the currently disclosed subject matter are described for illustrative purposes in relation to optical edge detection, it should be readily understood that such features are not intended to be limiting. The claims that follow this disclosure are intended to define the scope of the protected subject matter.
The accompanying drawings, which are incorporated in and constitute a part of this specification, show certain aspects of the subject matter disclosed herein and, together with the description, help explain some of the principles associated with the disclosed implementations. In the drawings,
One or more implementations of the current subject matter relate to methods, systems, articles of manufacture, and the like that may, among other possible advantages, provide determination of a location of a wireless device or a tag.
A myriad of applications, ranging from virtual reality/augmented reality (VR/AR) gaming to mission critical robotic surgery based applications demand centimeter (cm)-accurate localization of sensors, that are robust to blockages from hands and/or other obstacles in the environment. With this need, in the recent past, localization including ultra-wideband (UWB) based localization has become popular, because of its ability to achieve mm-accurate localization and pass through obstacles owing to its large bandwidth and larger wavelength, respectively. However, UWB based localization has not been scalable because of the fine-time-measurement based localization algorithms that have linearly increasing latency with increasing number of wireless devices (may also be referred to as tags) and readers in the environment.
In some implementations, the current subject matter relates to a scalable, robust, and cm-accurate UWB localization system. The current subject matter system may be configured to include a multi-antenna UWB board that may be configured to enable a multi-dimensional (e.g., two-dimensional (2D)) angle of arrival (AoA) measurements at each board. This may be configured to reduce the latency of the system (e.g., by a minimum of at least 10 times) and make UWB based localization scalable. Further, the current subject matter may be configured to execute a 2D AoA based 3D localization process to achieve a high localization accuracy (e.g., approximately 10 cm or less).
Accurate localization of wireless devices is important for many modern day applications, e.g., gaming, VR, sports analytic applications, inventory and personnel tracking, industrial Internet-of-things (IoT) applications, and many others. Conventional modem localization system demand robust, scalable, and low-latency performance of either the user's hand location (e.g., gaming, such as playing virtual tennis with a controller capturing hand-location, which requires location of hand and its motion to be captured in a low-latency fashion) and/or the robotic arm location (e.g., industrial automation). In industrial IoT applications (e.g., manufacturing and/or warehousing automation applications where robots need a real-time feedback at 1 KHz rate of the movement of arms to enable accurate maneuvering) require latency that should not increase with increasing number of sensors to be located in addition to preserving battery life of sensors. Further, loss of localization should not be tolerated because of blockage of line of sight (LOS) to the sensors.
To enable various applications, such as those discussed above, along with the localization capability in devices, the current subject matter may be configured to meet one or more (or all) of the following characteristics: a low latency and/or a real-time estimation characteristic, an infrastructure-aware characteristic, a long operation lifetime characteristic, and a multi-dimensional (e.g., 3D) accuracy characteristic, and/or any combination thereof. With regard to the low-latency and/or real-time estimation characteristic, many industrial and/or commercial applications may require location estimates of UWB tags to be acquired in real-time with a location update rate of up to a few 100's of Hz to ensure time-critical and/or safety decisions. For example, an automated robotic arm in an industrial setting that loads and unloads the inventory in close vicinity of a worker may be dependent on such accurate location estimation. The current subject matter's localization system may be configured to obtain an estimate of both the robotic arm and the worker in real-time to avoid any crashes and/or injuries. Conventional systems/algorithms (e.g., two-way ranging (TWR) based UWB localization systems) are not able to perform this estimation in real-time to meet the time-critical and/or safety requirements for these applications.
With regard to infrastructure-aware characteristic, the current subject matter may be configured to locate multiple wireless devices (e.g., tags) for inventory and/or personnel analytics and management (e.g., in industrial, construction, hospital, warehousing, etc. settings). This allows, for example, avoidance of collisions, accidents, etc. in industrial settings (e.g., using the current subject matter system, the machinery knows the position of all equipment and personnel). Existing systems suffer from poor latency as well as require multiple transmissions among various devices to determine location of tags, thereby lacking a real-time aspect of the system and increasing amount of traffic and power consumption across many devices.
The long operation lifetime characteristic (e.g., low power consumption) may enable long-battery based operation lifetime of tags. By contrast, conventional systems consume significant amounts of power and are not capable of prolonged operation.
The multi-dimensional (e.g., 3D) accuracy characteristic may enable the current subject matter system to accurately track the UWB tags to centimeter-grade accuracy in multiple dimensions (e.g., 3D) to avoid causing damage and/or crashes, for example, in the industrial settings. Existing system produce large localization errors (and may be limited to 2D), especially, in non-line of sight (NLoS) cases.
In some implementations, the current subject matter may be configured to include an ultra-wideband (UWB) based multi-dimensional (e.g., 3D) system that may be configured to achieve low-power, real-time, and cm-accurate tracking of wireless devices (e.g., tags). The current subject matter system may be configured to include one or more wireless devices (e.g., tags), one or more anchor devices, and/or one or more server and/or processor components. The tag(s) and the anchor(s) devices may be configured to communicate with one another to determine tag's location, movement direction, speed, etc., and/or any other parameters. The anchor(s) may be configured to communicate with one or more servers/processors to for the purposes of transmitting/receiving various information that may be relevant to a particular application setting (e.g., industrial warehouse, hospital, gaming, etc.).
One or more tags in the current subject matter system may be configured to achieve a low-power by offloading various communication and/or processing complexities from the tag to the infrastructure (e.g., anchor(s), server(s), etc.) and, in the process, making tag location available to the infrastructure. The anchor(s) may also be configured to offload communication/processing complexities to the infrastructure (e.g., server(s), processor(s), etc.), that may also enable providing tag's cm-accurate 3D location in real-time using a single transmission from the tag.
Further, the system 100 may be configured to include one or more servers, one or more databases, a cloud storage location, a memory, a file system, a file sharing platform, a streaming system platform and/or device, and/or in any other platform, device, system, etc., and/or any combination thereof. One or more components of the system 100 may be communicatively coupled using one or more communications networks. The communications networks can include at least one of the following: a wired network, a wireless network, a metropolitan area network (“MAN”), a local area network (“LAN”), a wide area network (“WAN”), a virtual local area network (“VLAN”), an internet, an extranet, an intranet, and/or any other type of network and/or any combination thereof.
The components of the system 100 may include any combination of hardware and/or software. In some implementations, such components may be disposed on one or more computing devices, such as, server(s), database(s), personal computer(s), laptop(s), cellular telephone(s), smartphone(s), tablet computer(s), and/or any other computing devices and/or any combination thereof. In some implementations, these components may be disposed on a single computing device and/or can be part of a single communications network. Alternatively, or in addition to, the components may be separately located from one another.
As shown in
In some implementations, to enable low-power and/or low-latency communications between the tag 102 and the anchor(s) 104, the tag 102 may be configured to consume as little power as possible and all complexity associated with communications, processing, etc. of signals may be positioned on the anchor 104 (rather than the tag 102). For this purpose, one or more anchors 104 may be configured to locate the tag accurately using a single broadcast transmission (e.g., “blink” transmission) from the tag 102. The broadcast transmission from the tag 102 may be received by all of the anchor(s) 104 of the system 100 that may then enable determination of the tag's location. Thus, the current subject matter may be configured to determination location (in multiple dimensions, e.g., 3D) of a tag 102 in real-time using a single transmission (as compared to using a 12 packet exchange in conventional systems). Further, use of a single transmission and avoiding any compute requirements on the tag 102 also significantly reduces consumption of power.
To be able to determine location of the tag 102 using a single transmission, the anchor(s) 104 may be configured to execute a 3D angle of arrival (AoA) determination by each anchor 104 in the system 100.
Each antenna 202 may be configured to be associated with a respective transceiver component 203 (a, b, . . . , h). Alternatively, one transceiver 203 may be used for communicating with one or more antennas 202.
Referring back to
In some implementations, the transceivers 203 may be configured to communicate with the processor (e.g., a microcontroller unit (MCU)) 210 using one or more serial peripheral interface (SPI) buses (e.g., 20 MHz SPI buses). The controller 210 may be configured to select one or more transceiver-antenna sets to communicate with (e.g., in a round-robin fashion). The clock distribution and timing synchronization components 204, 206 may be used to synchronize carrier frequency and phase by feeding the same reference clock values (which may be predetermined) to all transceivers 203. In some implementations, an ultra-wideband transceiver (disposed on the board 201) may be configured to provide an additional SYNC signal input, which may be used to reset a timestamp in each transceiver 203 to ensure that the transceivers are aligned. The SYNC signal may be sampled at a rising edge of the reference clock signal. The processor 21 may be configured to ensure that the SYNC signal is asserted only during the falling edge of the reference clock, thereby providing a maximum clearance from rising edges of the clock. Thus, the anchor 104 may be configured to achieve the required time, frequency, and phase synchronization by driving the transceivers 203 from the same clock source and performing wired time-base synchronization on the board 201.
In some implementations, each of the anchors 104, using the hardware components discussed above (as well as processes discussed below), may be configured to determine 3D angles of arrival (AoA) and combine them to obtain an accurate 3D location of the tag 102 in real-time. As stated above, the antennas 202 may be arranged in a predetermined pattern (or any desired pattern), where each of the antennas 202 may be configured to simultaneously receive transmissions and/or each transmission (e.g., “blink”) from the tag 102. The antennas 202 may be synchronized in time, frequency, and/or phase to perform an accurate 3D AoA determination by each anchor 104. To do so, the anchor 104 may include the clock distribution component 204 and the timing synchronization component 206.
Further, the current subject matter system 100 may be configured to execute a process (e.g., using processor 210 located on the anchor 104 and/or an external processor) for accurately determining a real-time localization of the tag 102 (e.g., using 3D AoA). The process uses time, frequency, and/or phase synchronized channel impulse responses (CIR) of the transmissions received from the tag 102 across one or more or all anchors 104 in the system 100 (shown in
Through various experimentation, the current subject matter system 100 achieved a median (90th percentile) 3D localization error that's 1.8× (2.5×) smaller than conventional systems in stationary conditions. Further, in high mobility conditions, the system 100 achieved a median (90th percentile) error 3.1× (4.3×) smaller than conventional system (e.g., than existing systems that use TWR). Moreover, the system 100 also achieved a localization latency of 1 millisecond per tag 102 location, which is 13× lower than the conventional two-way ranging (TWR) systems, thereby making system 100 highly scalable. Additionally, the system 100 achieved this localization latency and accuracy with a minimal power consumption where, the system 100 consumed 31 micro Joules of energy for one tag location estimate, as compared to 286 micro Joules of energy per location estimate for conventional systems. Further, the system 100 was able to track multiple tags 102 in real-time without any loss in its accuracy.
In some implementations, the tag's blink transmission may be enabled without modifying UWB protocols as follows. For example, initially, if a transmission from the tag 102 is rejected, the tag 102 may initiate a standard protocol compliant repeated transmissions (e.g., blinks) to inform the system 100 (e.g., any of the anchors 104) of its presence in the system 100's environment. Upon discovery of the tag 102, the anchors 104 may transmit a Range-Init response, which may be typical of the UWB protocol. During the Range-Init transmission, the anchors 104 may program the tag to only transmit a blink at a periodic interval to enable accurate localization of the tag 102. Thus, the tag 102 may need to transmit only a single blink transmission to inform all anchors 104 to receive it and, thereby, locate it simultaneously. This also may avoid extra processing by the tag 102, thereby reducing power-consumption on the tag 102. Additionally, the blink interval may be modified based on a number of co-located tags 102 in the environment of the system 100 to avoid packet collision. The 3D AoA and the tag 102 location determination may be performed by the system 100, thereby further removing additional processing and computational complexity from the tag 102. Moreover, use of a single blink transmission-based protocol may allow the tag's power to last longer (e.g., up to 2.4 years, as compared to conventional systems (e.g., 3-4 months of existing TWR based systems). Additionally, as stated above, this protocol may allow for location update rate in real-time with a low latency (e.g., 1 msec) for each location of the tag 102.
In some implementations, to accurately estimate location of the tag 102 using the process 306, shown in
The system 100 may be determine a first path index and apply a 2D FFT to previously estimate an angle of arrival (at 312).
Equation (1) may be used for a tag 102 that may be located at distance r from the anchor 104 and transmitting at a central frequency fc, where c is the speed of light, t=√−1, and ai, aj are the corresponding attenuation constants across the antennas 202. For a particular channel impulse response measurements on a particular antenna tap n, a simple transform, using equation (1), may be defined as follows
where P(θk, ϕl, n) is the likelihood at the direction of arrival of (θk, ϕl) corresponding to the time-index n, of the measured CIR. The above transform is a Fast Fourier transform. Further, due to the design of the antenna arrays, under no multi-path, there may be a unique solution for the actual direct path's 3D-AoA, (θ{circumflex over ( )}, θ{circumflex over ( )}) that may be expressed as follows
Equation (3) assumes that θϵ[−π/2, π/2] and ϕϵ[−π/2, π/2], no carrier frequency offset, and d≤λ/2, where λ is the wavelength of the carrier frequency.
At 314, the system 100 may be configured to execute a temporal tracking process, as discussed below in connection with
However, in some cases, multipath in a channel may cause corruption of the phase difference between some pairs of antennas 202, which may result in multiple ambiguous peaks in the theta-phi likelihood-map. To overcome phase distortion, the system 100 may be configured to execute the temporal tracking process 314 shown in
As shown in
At 504, a closet peak corresponding to 3D AoA for each anchor-tag pair may be determined. Additionally, at 506, a temporal tracker process may be applied to the each of the 2D FFT profiles to generate a “cleaned” 3D AoA for each anchor-tag pair. The temporal tracker process may be configured to track the tag over-time by estimating the tag's velocity from one or more previous N (e.g., 7) estimates, and may use that information to predict the tag's next location, based on the optimized tag location from the previous temporal estimate. The system 100's temporal tracker may be configured to use a global maxima peak (as for example shown in
To define the temporal tracker process, at 506, the system 100 may use maxima peaks derived at 312 (as shown in
In addition to the temporal tracker, the system 100 may use the prediction of the temporal tracker 506 to estimate a closest peak to it amongst the peaks in the current profile, at 504. The process 314 may then determine a weighted average, at 508, of both the temporal tracker 3D AoA estimate (θcleanedt, ϕcleanedt) and the closest peak finder 3D AoA estimate (θcloset, ϕcloset) to determine an accurate real-time 3D AoA estimate 509, (θULoct, ϕULoct) These weights, Wreliability(<1) may be used to determine a reliability of the current 3D AoA estimates of the temporal tracker (θcleanedt, ϕcleanedt) The weighting factor (Wreliability) may define an error distribution of each likelihood-map (e.g., possible locations of the tag 102), using weights (e.g., peaks, angular, and distance) to account for non-Gaussian 3D-AoA errors, where the corresponding weight coefficients (wp,t, wa,t, and wd,t) may be averaged to determine a weighting factor. The three weights may include the following inputs: θcleaned, θclose, and a number of peaks in the likelihood-map at time t. The first weight (wp,t) may correspond to a number of peaks in the likelihood-map; the second weight (wa,t) may account for erroneous 3D-AoA estimation following computations using Equation 2; and the third weight (wd,t) may be used to compare the difference between θcleaned and θclose, whereby this weight may accounts for large instantaneous changes in the likelihood-map, particularly in disappearances of the correct peak.
Further to determine an accurate 3D-AoA, the temporal tracking process may include re-initialization of θcleanedt to avoid erroneous 3D-AoA estimation. The θcleanedt estimation may be re-initialized along with reliable θcloset set estimations. In some exemplary, non-limiting implementations, θcloset set estimation may be considered reliable when it is within ±60°, and the weighting factor is within 0.35 (Wreliability<=0.35). Under these conditions, θcleanedt may be set to be the same as θcloset, i.e., θcleanedt=θcloset.
Subsequent to the triangulation, at 510, the location (i.e., XYZ(t)) of the tag 102 may be determined, at 512, using the following:
where θULock,t is the final theta estimation for anchor kϵ{1, 2, . . . , Nanchor} at time index, t. Thus, the system 100 may be configured to achieve an accurate real-time 3D AoA estimate from a single anchor 104.
Referring back to
l
k
≡p
k
=x
k
+t{right arrow over (v)}
k (5)
where, pk is any point along the line lk for a given translation of t away from the known point on the line, xk, and v→k=[sin (ϕ{circumflex over ( )}k), cos (ϕ{circumflex over ( )}k) sin (θ{circumflex over ( )}k), cos (ϕ{circumflex over ( )}k) cos (θ{circumflex over ( )}k)] is the unit vector defined in the direction defined by (θ{circumflex over ( )}k, ϕ{circumflex over ( )}k). With this definition of the line, lk, the location of the tag 102 xtag may be determined using the following:
where I may be an 3×3 identity matrix. Using this formulation, the system 100 may perform much faster accurate 3D localization that is at least 20× faster than a conventional TWR based localization algorithm.
The generalized 3D AoA estimation algorithm that may be used for any random 2D antenna arrays 202 whose relative antenna positions with respect to the first antenna may be expressed as (diA{acute over (P)}, θiAP, ϕiAP) for each i=2, 3, . . . , Nant antennas, where (diAP, θiAP, ϕiAP) are the distance, azimuth (e.g., measured with respect to positive z-axis), and polar angles (e.g., measured with respect to XZ-plane) of the ith antenna with respect to the first antenna, and the likelihood profile may be estimated for the FPI tap on vertical and horizontal axes, hvi(0), hhi(0) across each of the ith antenna may be expressed as follows:
Further, in systems where only one anchor 104 is deployed, the 3D AoA estimation may be used to determine tag's location at time instance, t, using standard spherical to Cartesian transforms as follows.
x
t
UWB
=−r
t
UWB cos(ϕtUWB)sin(θtUWB)
y
t
UWB
=−r
t
UWB sin(ϕtUWB)
z
t
UWB
=−r
t
UWB cos(ϕtUWB)cos(θtUWB) (8)
As can be seen from the table 700, the system 100 is capable of achieving a centimeter-accurate location of a tag in three-dimensional space. The lifespan of tag's battery using system 100 may be approximately 2.4 years. As discussed above, the system 100 relies on its infrastructure (i.e., anchors, processors, rather than tags). Lastly, the system has very low latency associated with communication and localization processes (e.g., approximately 1 msec). Conventional systems are clearly deficient when compared to the system 100's performance.
In some implementations, the current subject matter can be configured to be implemented in a system 800, as shown in
At 902, one or more second wireless devices (e.g., an anchor as shown in
At 904, each anchor device 104 may be configured to process the communications. For example, the anchor 104 may be configured to determine an angle of arrival of the signal transmission. The determination of the angle of arrival may involve estimation of the angle of arrival (includes one or more of its components, e.g., azimuth, polar angles of arrival, etc.), application of first path index and 2D FFT processing to the estimates across all antennas in the anchor device 104, and determining an accurate angle of arrival of the signal transmission, as discussed above with regard to
At 906, a location of the first wireless device in the environment may be determined based on the processed communications. The accurate angle of arrival information may be used by the processing equipment of the anchor devices 104 to determine an accurate location of the tag 102 in the environment of the system 100. Such determination may be performed in accordance with the operations of processes shown in
In some implementations, the current subject matter may include one or more of the following optional features. The communications may include at least one of: a received communication, a transmitted communication, and any combination thereof by at least one of: the first wireless device, one or more second wireless devices, and any combination thereof. Further, the communications may include a communication responsive to at least one of: the received communication, the transmitted communication, and any combination thereof. Additionally, the communications may include a signal transmission. Moreover, as stated above, the processing of the communications may include determining, based on the signal transmission, an angle of arrival of the signal transmission, and determining, using the determined angle of arrival of the signal transmission, the location of the first wireless device in the environment.
The signal transmission may be received using one or more second wireless devices (e.g., anchors 104) in a plurality of second wireless devices. Each second wireless device in the plurality of second wireless devices may include one or more antennas (e.g., antennas 202 which may include transceivers 203 shown in
In some implementations, each antenna may be configured to be synchronized using at least one clock reference signal. The clock reference signals may be generated using at least one processor of a second wireless device in the plurality of wireless devices receiving the signal transmission.
In some implementations, each antenna may be configured to be positioned a predetermined distance from another antenna in the one or more antennas. Such exemplary, non-limiting positioning is illustrated in
In some implementations, the antennas of each second wireless device in the plurality of second wireless devices may be configured to be synchronized using at least one of the following parameters: a time, a frequency, a phase, and any combination thereof.
In some implementations, at least one of the first and second wireless devices may be configured to be ultra-wideband wireless devices. The signal transmission may be an ultra-wideband signal transmission. In some implementations, the signal transmission may include a blink transmission.
In some implementations, the determining of the angle of arrival of the signal transmission may include estimating at least one of an azimuth angle of arrival and a polar angle of arrival for each antenna, combining estimated azimuth angles of arrival and polar angles of arrival for one or more antennas, and determining, based on the combined estimates of azimuth angles of arrival and polar angles of arrival for one or more antennas, an actual angle of arrival of the signal transmission.
In some implementations, the determining the actual angle of arrival of the signal transmission may be performed in real-time. The determined location of the first wireless device in the environment may correspond to the location of the first wireless device in a multi-dimensional space at a predetermined point in time.
In some implementations, the first wireless device may include at least one of a stationary first wireless device, a moving wireless device, and any combination thereof.
In some implementations, the determination of the location of the first wireless devices may include determining the location of the first wireless device using a single second wireless device in the plurality of second wireless devices by executing a two-way-ranging communication protocol at one or more antennas of the single second wireless device. Further, the determination of the location of the first wireless device may include determining the location of the first wireless device using at least one of the following: at least one of one or more azimuth angles, one or more polar angles, and any combination thereof associated with the signal transmission received by at least two or more of the second wireless devices in the plurality of second wireless devices; at least one of one or more azimuth angles, one or more polar angles, one or more values resulting from execution of the two-way-ranging communication protocol, and any combination thereof by at least one or more of the second wireless devices in the plurality of second wireless devices; and any combination thereof.
In some implementations, the current subject matter relates to an apparatus (e.g., for determination of a location of a wireless device (e.g., tag 102)). The apparatus (e.g., as shown in
In some implementations, the current subject matter may include one or more of the following optional features. One or more communications may include a signal transmission. The processing devices may be configured to determine, based on the signal transmission, an angle of arrival of the signal transmission, and determine, using the determined angle of arrival of the signal transmission, the location of the wireless device in the environment. One or more antennas may be configured to receive the signal transmission from the wireless device and/or transmit at least another signal to the wireless device.
In some implementations, each antenna may be configured to be synchronized using at most one clock reference signal, the clock reference signal being generated by the at least one processing device. Each antenna may be further configured to be oriented in a predetermined direction. One or more antennas may be configured to be synchronized using at least one of the following parameters: a time, a frequency, a phase, and any combination thereof.
In some implementations, the signal transmission is an ultra-wideband signal transmission. Moreover, the signal transmission may include a blink transmission.
In some implementations, at least one processing device may determine the angle of arrival of the signal transmission by estimating at least one of an azimuth angle of arrival and a polar angle of arrival for each antenna, combining estimated azimuth angles of arrival and polar angles of arrival for one or more antennas, and determining, based on the combined estimates of azimuth angles of arrival and polar angles of arrival for one or more antennas, an actual angle of arrival of the signal transmission. Further, the determination of the actual angle of arrival of the signal transmission may be performed in real-time. The determined location of the wireless device in the environment may correspond to the location of the wireless device in a multi-dimensional space at a predetermined point in time.
In some implementations, the wireless device may include at least one of: a stationary wireless device, a moving wireless device, and any combination thereof.
In some implementations, the determination of the location of the wireless device may include executing a two-way-ranging communication protocol at one or more antennas. Further, the determination of the location of the wireless device may include determining the location of the wireless device using at least one of the following: at least one of one or more azimuth angles, one or more polar angles, and any combination thereof associated with the signal transmission; at least one of one or more azimuth angles, one or more polar angles, one or more values resulting from execution of the two-way-ranging communication protocol, and any combination thereof; and any combination thereof.
The systems and methods disclosed herein can be embodied in various forms including, for example, a data processor, such as a computer that also includes a database, digital electronic circuitry, firmware, software, or in combinations of them. Moreover, the above-noted features and other aspects and principles of the present disclosed implementations can be implemented in various environments. Such environments and related applications can be specially constructed for performing the various processes and operations according to the disclosed implementations or they can include a general-purpose computer or computing platform selectively activated or reconfigured by code to provide the necessary functionality. The processes disclosed herein are not inherently related to any particular computer, network, architecture, environment, or other apparatus, and can be implemented by a suitable combination of hardware, software, and/or firmware. For example, various general-purpose machines can be used with programs written in accordance with teachings of the disclosed implementations, or it can be more convenient to construct a specialized apparatus or system to perform the required methods and techniques.
Although ordinal numbers such as first, second, and the like can, in some situations, relate to an order; as used in this document ordinal numbers do not necessarily imply an order. For example, ordinal numbers can be merely used to distinguish one item from another. For example, to distinguish a first event from a second event, but need not imply any chronological ordering or a fixed reference system (such that a first event in one paragraph of the description can be different from a first event in another paragraph of the description).
The foregoing description is intended to illustrate but not to limit the scope of the invention, which is defined by the scope of the appended claims. Other implementations are within the scope of the following claims.
These computer programs, which can also be referred to programs, software, software applications, applications, components, or code, include machine instructions for a programmable processor, and can be implemented in a high-level procedural and/or object-oriented programming language, and/or in assembly/machine language. As used herein, the term “machine-readable medium” refers to any computer program product, apparatus and/or device, such as for example magnetic discs, optical disks, memory, and Programmable Logic Devices (PLDs), used to provide machine instructions and/or data to a programmable processor, including a machine-readable medium that receives machine instructions as a machine-readable signal. The term “machine-readable signal” refers to any signal used to provide machine instructions and/or data to a programmable processor. The machine-readable medium can store such machine instructions non-transitorily, such as for example as would a non-transient solid state memory or a magnetic hard drive or any equivalent storage medium. The machine-readable medium can alternatively or additionally store such machine instructions in a transient manner, such as for example as would a processor cache or other random access memory associated with one or more physical processor cores.
To provide for interaction with a user, the subject matter described herein can be implemented on a computer having a display device, such as for example a cathode ray tube (CRT) or a liquid crystal display (LCD) monitor for displaying information to the user and a keyboard and a pointing device, such as for example a mouse or a trackball, by which the user can provide input to the computer. Other kinds of devices can be used to provide for interaction with a user as well. For example, feedback provided to the user can be any form of sensory feedback, such as for example visual feedback, auditory feedback, or tactile feedback; and input from the user can be received in any form, including, but not limited to, acoustic, speech, or tactile input.
The subject matter described herein can be implemented in a computing system that includes a back-end component, such as for example one or more data servers, or that includes a middleware component, such as for example one or more application servers, or that includes a front-end component, such as for example one or more client computers having a graphical user interface or a Web browser through which a user can interact with an implementation of the subject matter described herein, or any combination of such back-end, middleware, or front-end components. The components of the system can be interconnected by any form or medium of digital data communication, such as for example a communication network. Examples of communication networks include, but are not limited to, a local area network (“LAN”), a wide area network (“WAN”), and the Internet.
The computing system can include clients and servers. A client and server are generally, but not exclusively, remote from each other and typically interact through a communication network. The relationship of client and server arises by virtue of computer programs running on the respective computers and having a client-server relationship to each other.
The implementations set forth in the foregoing description do not represent all implementations consistent with the subject matter described herein. Instead, they are merely some examples consistent with aspects related to the described subject matter. Although a few variations have been described in detail above, other modifications or additions are possible. In particular, further features and/or variations can be provided in addition to those set forth herein. For example, the implementations described above can be directed to various combinations and sub-combinations of the disclosed features and/or combinations and sub-combinations of several further features disclosed above. In addition, the logic flows depicted in the accompanying figures and/or described herein do not necessarily require the particular order shown, or sequential order, to achieve desirable results. Other implementations can be within the scope of the following claims.
The present application claims priority to U.S. Provisional Patent Appl. No. 63/129,059 to Zhao et al., filed Dec. 22, 2020, and entitled “Robust, Scalable and Accurate Ultra-Wideband Tag Localization”, and incorporates its disclosure herein by reference in its entirety.
Filing Document | Filing Date | Country | Kind |
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PCT/US2021/064984 | 12/22/2021 | WO |
Number | Date | Country | |
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63129059 | Dec 2020 | US |