Ultra-wideband positioning method, positioning server, and user terminal

Abstract

Embodiments of the present disclosure provide an ultra-wideband positioning method, a positioning server, and a user terminal. The method comprises: on the basis of initial location information before movement of the user terminal, first time of flight information reported by an ultra-wideband base station and first assisted positioning information reported during movement of the user terminal, determining first positioning information after movement of the user terminal; and on the basis of the first positioning information and second assisted positioning information reported by the user terminal, determining second positioning information within a preset time interval after the user terminal receives the first positioning information.

Description

Ultra-wideband positioning method, positioning server and user terminal

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This disclosure is based on Chinese patent application CN202311731793.X filed on December 15, 2023, entitled “Ultra-wideband positioning method, positioning server and user terminal”, and claims the priority of the patent application, and all the contents disclosed therein are incorporated into this disclosure by reference. Technical Field

[0003] The present disclosure relates to the field of communications, and in particular to an ultra-wideband positioning method, a positioning server, and a user terminal. Background Art

[0004] In open outdoor environments, satellite positioning technology can achieve sub-meter or even centimeter-level positioning accuracy. However, satellite positioning is subject to signal strength constraints and is highly susceptible to signal interference such as obstruction and multipath. In urban canyons surrounded by tall buildings or in enclosed indoor environments, satellite positioning can be inaccurate or even impossible. To meet indoor positioning needs for resource locating, indoor intelligent robots, shopping mall navigation and guidance, emergency evacuation, and to address the "last mile" problem that outdoor navigation cannot reach, indoor positioning has become a hot topic for research institutions and related companies.

[0005] UWB (Ultra Wide Band) technology combines numerous advantages, including high positioning accuracy, high security, good penetration, strong anti-interference, low power consumption, and long transmission distance. Its positioning accuracy is at the centimeter level, generally reaching 10-30cm, and up to within 10cm, with a measurable range of up to 100m, far exceeding indoor positioning technologies such as WiFi and Bluetooth. Furthermore, the UWB positioning frequency band is compatible with WiFi, Bluetooth, and 5G bands. However, existing UWB positioning solutions require the deployment of more than two base stations, which is costly. Furthermore, clock synchronization is required between multiple base stations to ensure the accuracy of the time difference. Therefore, reducing UWB costs has become a bottleneck in its development.

[0006] Summary of the Invention

[0007] The embodiments of the present disclosure provide an ultra-wideband positioning method, a positioning server, and a user terminal to at least solve the problem of high UWB base station deployment cost in related technologies.

[0008] According to one embodiment of the present disclosure, an ultra-wideband positioning method is provided, which is applied to a positioning server, including: determining first positioning information of a user terminal after movement based on initial position information of the user terminal before movement, first flight time information reported by an ultra-wideband base station, and first auxiliary positioning information reported during movement of the user terminal; and determining second positioning information of the user terminal within a preset time interval after receiving the first positioning information based on the first positioning information and second auxiliary positioning information reported by the user terminal.

[0009] According to another embodiment of the present disclosure, an ultra-wideband positioning method is provided, which is applied to a user terminal, including: reporting initial position information before movement and first auxiliary positioning information during movement to a positioning server, and receiving first positioning information returned by the positioning server, wherein the first positioning information is determined based on the initial position information, the first auxiliary positioning information, and the first flight time information reported by the ultra-wideband base station; within a preset time interval after receiving the first positioning information, reporting second auxiliary positioning information to the positioning server, and receiving second positioning information returned by the positioning server, wherein the second positioning information is determined based on the first positioning information and the second auxiliary positioning information.

[0010] According to another embodiment of the present disclosure, a positioning server is provided, including: a first positioning module, configured to determine first positioning information of the user terminal after movement based on initial position information of the user terminal before movement, first flight time information reported by an ultra-wideband base station, and first auxiliary positioning information reported during the movement of the user terminal; and a second positioning module, configured to determine second positioning information of the user terminal within a preset time interval after receiving the first positioning information based on the first positioning information and the second auxiliary positioning information reported by the user terminal.

[0011] According to another embodiment of the present disclosure, a user terminal is provided, including: a first reporting module, configured to report initial position information before movement and first auxiliary positioning information during movement to a positioning server; a first receiving module, configured to receive first positioning information returned by the positioning server, wherein the first positioning information is determined based on the initial position information, the first auxiliary positioning information and the first flight time information reported by the ultra-wideband base station; a second reporting module, configured to report second auxiliary positioning information to the positioning server within a preset time interval after receiving the first positioning information; and a second receiving module, configured to receive second positioning information returned by the positioning server, wherein the second positioning information is determined based on the first positioning information and the second auxiliary positioning information.

[0012] According to another embodiment of the present disclosure, a computer-readable storage medium is provided, in which a computer program is stored. The computer program is configured to execute the steps of any one of the above method embodiments when running.

[0013] According to another embodiment of the present disclosure, an electronic device is provided, including a memory and a processor, wherein the memory stores a computer program, and the processor is configured to run the computer program to perform the steps in any one of the above method embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] FIG1 is a hardware structure block diagram of a mobile terminal for executing an ultra-wideband positioning method according to an embodiment of the present disclosure;

[0015] FIG2 is a structural block diagram of a two-dimensional UWB positioning system according to an embodiment of the present disclosure;

[0016] FIG3 is a structural block diagram of a mobile terminal according to an embodiment of the present disclosure;

[0017] FIG4 is a flow chart of an ultra-wideband positioning method according to an embodiment of the present disclosure;

[0018] FIG5 is a flow chart of an ultra-wideband positioning method according to another embodiment of the present disclosure;

[0019] FIG6 is a structural block diagram of a positioning server according to an embodiment of the present disclosure;

[0020] FIG7 is a structural block diagram of a user terminal according to an embodiment of the present disclosure;

[0021] FIG8 is a schematic diagram of a TOF-based positioning method according to an embodiment of the present disclosure;

[0022] FIG9 is a schematic diagram of an unknown point positioning principle according to an embodiment of the present disclosure;

[0023] FIG10 is a schematic diagram of a TDOA-based positioning method according to an embodiment of the present disclosure;

[0024] FIG11 is a schematic diagram of TOF measurement between a tag and a base station according to an embodiment of the present disclosure;

[0025] FIG12 is a schematic diagram of a positioning method based on fusion trajectory extrapolation according to an embodiment of the present disclosure;

[0026] FIG13 is a flowchart of a two-dimensional UWB positioning method according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0027] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings and in conjunction with embodiments.

[0028] It should be noted that the terms "first", "second", etc. in the specification and claims of the present disclosure and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence.

[0029] The method embodiments provided in the embodiments of the present application can be executed in a mobile terminal, a computer terminal, a network device or a similar computing device. Taking running on a mobile terminal as an example, Figure 1 is a hardware structure block diagram of a mobile terminal running the ultra-wideband positioning method in an embodiment of the present disclosure. As shown in Figure 1, the mobile terminal may include one or more (only one is shown in Figure 1) processors 102 (the processor 102 may include but is not limited to a processing device such as a microprocessor or a programmable logic device) and a memory 104 for storing data, wherein the above-mentioned mobile terminal may also include a transmission device 106 and an input and output device 108 for communication functions. It can be understood by those skilled in the art that the structure shown in Figure 1 is only for illustration and does not limit the structure of the above-mentioned mobile terminal. For example, the mobile terminal may also include more or fewer components than those shown in Figure 1, or have a configuration different from that shown in Figure 1.

[0030] The memory 104 can be used to store computer programs, such as software programs and modules of application software, such as the computer program corresponding to the ultra-wideband positioning method in the embodiments of the present disclosure. The processor 102 executes the computer programs stored in the memory 104 to execute various functional applications and data processing, thereby implementing the above-mentioned method. The memory 104 may include high-speed random access memory and may also include non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some examples, the memory 104 may further include memory remotely located relative to the processor 102, and these remote memories may be connected to the mobile terminal via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0031] The transmission device 106 is used to receive or send data via a network. A specific example of the aforementioned network may include a wireless network provided by the mobile terminal's communications provider. In one embodiment, the transmission device 106 includes a network interface controller (NIC), which can be connected to other network devices via a base station to enable communication with the Internet. In another embodiment, the transmission device 106 may be a radio frequency (RF) module, which is used to communicate with the Internet wirelessly.

[0032] The embodiment of the present application can run on the two-dimensional UWB positioning system shown in Figure 2. As shown in Figure 2, the system includes: a mobile terminal 10, an ultra-wideband base station 20, a wireless communication module 30, a positioning server 40 and a display device 50.

[0033] The mobile terminal 10 interacts with the ultra-wideband base station 20 for positioning signals, initializes the tag and positioning base station according to the adopted algorithm, and enters the normal positioning process; wherein the ultra-wideband base station 20 includes a first ultra-wideband base station 21 and a second ultra-wideband base station 22.

[0034] The ultra-wideband base station 20 connects the wireless communication module 30 to the back-end server of the positioning server 40 through the wireless communication network, and uploads the time or time difference of the tag transmission signal received by the ultra-wideband base station 20 to the positioning server 40 for position calculation.

[0035] The wireless communication module 30 serves as an intermediary between the UWB base station 20 and the backend server of the positioning server 40 .

[0036] The positioning server 40 is used to process the positioning information sent from the ultra-wideband base station 20 and the mobile terminal 10, analyze it according to the corresponding algorithm, and finally return the positioning result.

[0037] The display device 50 may be the mobile terminal 10 itself, and displays the current location of the mobile device in combination with a corresponding graphical interface and map software.

[0038] As shown in FIG3 , the mobile terminal 10 includes a positioning module 11 , wherein the positioning module further includes four parts: a power management module 111 , a program module 112 , a sensor module 113 and a UWB tag 114 .

[0039] The power management module 111 is configured to provide power for tag transmission and reception;

[0040] Program module 112 is configured to generate a mobile terminal positioning signal, perform signal processing on the received positioning signal, and set the transmission power of the ultra-wideband base station and the tag according to the distances d1 and d2 between the tag and the first and second ultra-wideband base stations;

[0041] For example: when max(d1,d2) <d T1 When , the power level is selected as pc1;

[0042] When d T1 <max(d1,d2)<d T2 When , the power level is pc2;

[0043] When d T2 <max(d1,d2)<d T3When the power level is pc3, max() is the maximum value function, which is used to select the maximum value from d1 and d2. T1 d T2 d T3 are preset thresholds respectively.

[0044] The sensor module 113 includes a gyroscope and an accelerometer, which identifies the movement direction and acceleration information of the mobile terminal 10 through the gyroscope and the accelerometer. Further, based on the identified movement direction and acceleration information, the position information of the mobile terminal 10 can be determined, and the movement direction, acceleration information, and position information can be uploaded to the positioning server in real time for use in calculating the tag's trajectory;

[0045] The UWB tag 114 is used to transmit and receive UWB signals.

[0046] In this embodiment, an ultra-wideband positioning method running on the above-mentioned mobile terminal or two-dimensional UWB positioning system is provided, which is applied to the positioning server 40. FIG4 is a flow chart of the ultra-wideband positioning method according to an embodiment of the present disclosure. The method is applied to the positioning server. As shown in FIG4, the process includes the following steps:

[0047] Step S402 , determining the first positioning information of the user terminal after movement based on the initial position information of the user terminal before movement, the first flight time information reported by the ultra-wideband base station, and the first auxiliary positioning information reported during the movement of the user terminal; wherein the user terminal is equivalent to the above-mentioned mobile terminal 10 .

[0048] In this embodiment, an ultra-wideband tag (ie, a UWB tag) is provided in the user terminal; and the ultra-wideband base station includes a first ultra-wideband base station and a second ultra-wideband base station.

[0049] In one embodiment, determining the first positioning information includes:

[0050] The UWB signals sent by the user terminal to the first ultra-wideband base station and the second ultra-wideband base station respectively;

[0051] After receiving the UWB signal, the first ultra-wideband base station and the second ultra-wideband base station report first flight time information to the positioning server 40, wherein the first flight time information reported by the first ultra-wideband base station carries the one-way time t1 of the UWB signal from the user terminal to the first ultra-wideband base station, and the first flight time information reported by the second ultra-wideband base station carries the one-way time t2 of the UWB signal from the user terminal to the second ultra-wideband base station;

[0052] The positioning server determines the distances d1 and d2 from the user terminal to the first ultra-wideband base station and the second ultra-wideband base station based on the acquired t1 and t2. The positioning server then establishes and solves a set of quadratic equations based on d1, d2, the location of the first ultra-wideband base station, and the location of the second ultra-wideband base station.

[0053] The positioning server determines the first positioning information from the solution of the quadratic equation system (i.e., the rough position information of the user terminal after movement), combined with the initial position information of the user terminal before movement and the first auxiliary positioning information. The first auxiliary positioning information includes information such as movement direction, acceleration information, and posture information collected by the user terminal's sensor module.

[0054] In this embodiment, the positioning method used is a TOF method combined with trajectory estimation. Under this method, the trajectory estimation method can compensate for the reduction in positioning accuracy caused by reducing the number of ultra-wideband base stations. Therefore, only two ultra-wideband base stations are required to achieve accurate positioning of the terminal, thereby achieving high-precision positioning and effectively reducing the deployment cost of the base stations.

[0055] In this embodiment, the first auxiliary positioning information is collected and reported by the sensor module 113 .

[0056] Step S404: Determine second positioning information of the user terminal within a preset time interval after receiving the first positioning information based on the first positioning information and the second auxiliary positioning information reported by the user terminal.

[0057] In one embodiment, after the first positioning information is determined, the positioning information of the user terminal within a subsequent preset time interval is the second positioning information, and the second positioning information is determined only by trajectory inference performed by a module of the user terminal.

[0058] In one embodiment, determining the second positioning information includes:

[0059] The second positioning information is determined based on the first positioning information and in combination with the moving direction, acceleration information and posture information of the user terminal within the preset time interval reported by the sensor module of the user terminal.

[0060] In step S404 of this embodiment, the second positioning information of the user terminal within a preset time interval after receiving the first positioning information is determined, including: determining the movement speed and movement direction of the user terminal within the preset time interval through the second auxiliary positioning information, and obtaining a speed calculation result and a direction calculation result; and determining the second positioning information by combining the speed calculation result, the direction calculation result and the first positioning information.

[0061] In one embodiment, after determining that the user terminal receives the second positioning information within a preset time interval after receiving the first positioning information, that is, after the trajectory calculation positioning is completed, the TOF method combined with the trajectory calculation fusion positioning method is restored, and the base station positioning resources are reallocated to the terminal, that is, the third auxiliary positioning information reported by the terminal, the second flight time information reported by the ultra-wideband base station, and the second positioning information are determined. In this way, the trajectory calculation positioning method that does not occupy base station resources and the TOF method combined with the trajectory calculation positioning method that occupies base station resources work alternately, which not only ensures positioning accuracy but also expands system capacity.

[0062] In this embodiment, the second auxiliary positioning information and the third auxiliary positioning information are both collected and reported by the sensor module 113 .

[0063] Through the above steps, within a preset time interval after receiving the first positioning information, the positioning server can obtain the positioning information of the user terminal in real time by combining the first positioning information with the second auxiliary positioning information reported by the user terminal without relying on the base station reporting information. The above method can reduce the number of base stations required for positioning while ensuring positioning accuracy. Therefore, it can solve the problem of high UWB base station deployment cost in related technologies and achieve the effect of improving positioning accuracy.

[0064] The present disclosure also provides an ultra-wideband positioning method, which is applied to a user terminal. FIG5 is a flow chart of an ultra-wideband positioning method according to another embodiment of the present disclosure. The method is applied to a user terminal, i.e., a mobile terminal 10. As shown in FIG5 , the method includes the following steps:

[0065] Step S502: Report the initial position information before movement and the first auxiliary positioning information during movement to the positioning server, and receive the first positioning information returned by the positioning server, wherein the first positioning information is determined based on the initial position information, the first auxiliary positioning information and the first flight time information reported by the ultra-wideband base station.

[0066] In one embodiment, the ultra-wideband base station includes a first ultra-wideband base station and a second ultra-wideband base station.

[0067] Before step S502 of this embodiment, the method further includes: determining a first distance value between the user terminal and the first ultra-wideband base station, and a second distance value between the user terminal and the second ultra-wideband base station; comparing the larger distance value of the first distance value and the second distance value with a preset distance threshold, and setting a transceiver power level based on the comparison result; and interacting with the first ultra-wideband base station and the second ultra-wideband based on the transceiver power level. Positioning signals are exchanged.

[0068] By comparing the larger distance value of the first distance value and the second distance value with a preset distance threshold, and setting the transceiver power level based on the comparison result, the user terminal and the ultra-wideband base station can exchange information at an appropriate transceiver power level. For example, when the larger distance value is less than or equal to the preset distance threshold, information exchange can be performed at a smaller transceiver power level; when the larger distance value is greater than the preset distance threshold, information exchange can be performed at an increased transceiver power level; in this way, power consumption of the device can be saved.

[0069] In one embodiment, the first auxiliary positioning information or the second auxiliary positioning information includes at least one of the following: direction information of the user terminal, acceleration direction information of the user terminal, and posture information of the user terminal. The posture information refers to the current posture of the user terminal, which facilitates the positioning server to more accurately determine the positioning information of the user terminal.

[0070] In one embodiment, the first auxiliary positioning information and the second auxiliary positioning information include at least one of the following: direction information of the user terminal, acceleration direction information of the user terminal, and posture information of the user terminal.

[0071] In step S502 of this embodiment, after receiving the first positioning information returned by the positioning server, the method further includes: releasing the occupied base station positioning window resources of the ultra-wideband base station, wherein the base station positioning window resources are used for positioning information interaction between the user terminal and the ultra-wideband base station.

[0072] When there are many user terminals, some user terminals use trajectory estimation positioning instead of TOF after determining the first positioning information, which can release the occupation of positioning base station resources and thus alleviate the pressure on base station resources.

[0073] Step S504: within a preset time interval after receiving the first positioning information, report second auxiliary positioning information to the positioning server, and receive second positioning information returned by the positioning server, wherein the second positioning information is determined based on the first positioning information and the second auxiliary positioning information.

[0074] In one embodiment, the method further includes: determining the frequency of positioning information interaction between the user terminal and the ultra-wideband base station (i.e., the tag refresh rate) based on the moving speed and positioning accuracy requirements of the user terminal; wherein the positioning information interaction is used by the ultra-wideband base station to obtain the flight time.

[0075] Different tag refresh rates correspond to different positioning accuracy. Therefore, the tag refresh rate can be determined according to the positioning accuracy requirements, so that the TOF positioning accuracy requirements can be met with an appropriate tag refresh rate.

[0076] For example: determine the threshold n of the number of tags that can be accommodated (number of user terminals). When the number of tags that the system simultaneously participates in positioning is lower than the threshold n, increase the tag positioning refresh rate to improve positioning accuracy. When the number of positioning tags is greater than or equal to n, the refresh rate is not adjusted.

[0077] Through the description of the above implementation methods, those skilled in the art can clearly understand that the method according to the above embodiment can be implemented by means of software plus the necessary general hardware platform, and of course it can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present disclosure is essentially or the part that contributes to the prior art can be embodied in the form of a software product, which is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk), including a number of instructions for enabling a terminal device (which can be a mobile phone, computer, server, or network device, etc.) to execute the methods described in each embodiment of the present disclosure.

[0078] This embodiment also provides a positioning server and a user terminal, which are used to implement the above-mentioned embodiments and preferred implementations. Details already described will not be repeated here. As used below, the term "module" may refer to a combination of software and / or hardware that implements a predetermined function. Although the devices described in the following embodiments are preferably implemented in software, implementation using hardware, or a combination of software and hardware, is also possible and contemplated.

[0079] FIG6 is a structural block diagram of a positioning server according to an embodiment of the present disclosure. As shown in FIG6 , the positioning server 40 includes a first positioning module 41 and a second positioning module 42 .

[0080] The first positioning module 41 is configured to determine first positioning information of the user terminal after the user terminal moves based on the initial position information of the user terminal before the user terminal moves, the first flight time information reported by the ultra-wideband base station, and the first auxiliary positioning information reported during the movement of the user terminal;

[0081] The second positioning module 42 is configured to determine second positioning information of the user terminal within a preset time interval after receiving the first positioning information based on the first positioning information and the second auxiliary positioning information reported by the user terminal.

[0082] FIG7 is a structural block diagram of a user terminal according to an embodiment of the present disclosure. As shown in FIG7 , the user terminal further includes: a first reporting module 71 , a first receiving module 72 , a second reporting module 73 and a second receiving module 74 .

[0083] A first reporting module 71 is configured to report the initial position information before the movement and the first auxiliary positioning information during the movement to the positioning server;

[0084] A first receiving module 72 is configured to receive first positioning information returned by the positioning server, wherein the first positioning information is determined based on the initial position information, the first auxiliary positioning information, and the first flight time information reported by the ultra-wideband base station;

[0085] A second reporting module 73 is configured to report second auxiliary positioning information to the positioning server within a preset time interval after receiving the first positioning information;

[0086] The second receiving module 74 is configured to receive second positioning information returned by the positioning server, wherein the second positioning information is determined based on the first positioning information and the second auxiliary positioning information.

[0087] The user terminal is equivalent to the mobile terminal 10 in the above embodiment. The sensor module 113 in the above embodiment functionally includes the functions of the first reporting module 71 and the second reporting module 73. The UWB tag 114 in the above embodiment functionally includes the functions of the first receiving module 72 and the second receiving module 74.

[0088] It should be noted that the above modules can be implemented through software or hardware. For the latter, it can be implemented in the following ways, but not limited to: the above modules are all located in the same processor; or the above modules are located in different processors in any combination.

[0089] Compared with indoor positioning technologies such as BLE (Bluetooth Low Energy) and WiFi, UWB (Ultra Wide Band) positioning has the advantages of low power consumption, large bandwidth, strong anti-interference ability, resistance to multipath loss and high positioning accuracy.

[0090] Unlike most wireless technologies, UWB positioning works through pulsed radio, i.e. using a series of pulses over a wide frequency band.

[0091] Compared to satellite, WiFi, and Bluetooth, which use modulated sine waves in narrow frequency bands to transmit information, UWB pulses have the following characteristics:

[0092] 1. Data is transmitted using non-sinusoidal narrow pulses ranging from nanoseconds to microseconds, which can be recognized even in noisy channel environments.

[0093] Compared to other technologies like WiFi or BLE, UWB pulses are more suitable for ToF ranging in dense multipath environments. Due to their extremely high operating frequency and low duty cycle, they offer high resolution. Multipath signals from narrow pulses are less likely to overlap in time, making it easier to separate radio signals reaching the receiver via multiple paths in an IR-UWB system.

[0094] The operating frequency band of UWB technology covers a total of 7 GHz bands, from 3G to 5G and from 6G to 10G, which is far away from the busy ISM band concentrated around 2.4GHz; among them, the UWB pulses used for positioning and ranging operate in the frequency range between 6.5 and 8GHz, and will not interfere with wireless transmissions occurring in other frequency bands of the spectrum. This is also the reason why UWB can coexist with satellite navigation, Wi-Fi, and Bluetooth.

[0095] Common UWB positioning solutions include TOF (Time of Flight), TDOA (Time Difference of Arrival), and AOA (Angle of Arrival). All three solutions have their own limitations. The following briefly introduces the TOF and TDOA solutions.

[0096] TOF solution:

[0097] The TOF-based positioning algorithm, which uses the time difference of flight to measure distance, is generally a two-way ranging technology. It uses the time it takes for the signal to travel back and forth between two asynchronous transceivers to measure the distance between nodes.

[0098] For example, as shown in Figure 8, the time interval from the reference point transmitting the signal to receiving the response is recorded as t roundA The time interval between the unknown point receiving the data packet and sending a response is recorded as t replyB , then the one-way flight time of the signal in the air is (t roundA -t replyB ) / 2, and then multiply the time by the propagation speed of electromagnetic waves in the air to get the distance between the reference point and the unknown point.

[0099] For another example, as shown in FIG9 , circles are drawn based on the distances from multiple reference points to the unknown point, and the circles intersect at a point, which is the position of the unknown point.

[0100] Since TOF positioning requires round-trip communication between the base station and the tag, it will increase power consumption and have a relatively short battery life. In addition, the number of UWB wireless signals that a UWB channel can accommodate simultaneously is fixed, and a single TOF positioning consumes a large number of UWB wireless signals, which will result in a general concurrency of the tag as a whole.

[0101] TDOA solution:

[0102] The TDOA-based positioning algorithm pre-synchronizes the clocks of all reference points. The unknown point then transmits a signal, which is received at different reference points at different times. The time from one reference point to the signal's arrival is used as a benchmark, and the time difference of arrival of the positioning signal is subtracted from the time the other reference points receive the signal. A hyperbola can be constructed based on the TDOA values ​​between the unknown point and the two reference points. Two-dimensional positioning requires at least three reference points to establish a set of hyperbola equations, which are then solved to estimate the unknown point's position, as shown in Figure 10.

[0103] The TDOA positioning solution requires a large number of reference base stations, resulting in high deployment costs. At the same time, each base station needs clock synchronization to ensure the accuracy of the arrival time difference between multiple base stations. Since the tag end only sends positioning messages but does not receive them, data aggregation and collaborative positioning are difficult to achieve.

[0104] Table 1 compares the three UWB positioning algorithms in terms of various wireless positioning indicators, including positioning accuracy, environmental adaptability, power consumption, scale, base station density, and price and cost.

[0105] Table 1

[0106] The disclosed embodiments are used for positioning devices such as mobile terminals (i.e., user terminals in the above embodiments), and solve the problems of redundant positioning base stations, low system capacity (i.e., low number of locatable tags), and terminal tag life in current mainstream positioning solutions. The tag refresh rate is appropriately adjusted according to the usage status of the mobile terminal and the number of system devices, and multiple positioning algorithms are flexibly integrated to solve the problem of high base station deployment cost in UWB indoor positioning without affecting positioning accuracy. The number of base stations used in the positioning process of positioning tags is reduced, and the number of tags that the system can accommodate is increased while ensuring accurate positioning, thereby reducing system power consumption.

[0107] Since the TDOA system tag only sends a single positioning message without receiving it, collaborative positioning is difficult to achieve, and requires many positioning base stations. Generally, four base stations are required to complete positioning, so the TOF positioning method is adopted in the embodiment of the present disclosure. However, as mentioned above, in the conventional TOF positioning method, one TOF positioning requires the tag and the positioning base station to send and receive positioning signals in a round trip. Therefore, compared with the TDOA technology, TOF occupies more base station time and the system capacity is relatively small. In this regard, the trajectory calculation technology is adopted in each embodiment of the present disclosure. Trajectory calculation positioning is used instead of TOF within a certain time interval ΔT to release the occupation of positioning base station resources. When there are many system positioning tags, the pressure on base station resources can be alleviated. At the same time, trajectory calculation combined with the TOF method can ensure the accuracy of positioning to a certain extent.

[0108] In practical applications, since all tags and base stations share channels, the TOF between the tag and each base station must be measured sequentially. As shown in Figure 11, if the node's position moves rapidly during the round-trip ranging process with each base station, the positioning will have a large deviation. The positioning error can be minimized by integrating trajectory extrapolation technology.

[0109] Figure 12 is a schematic diagram of the positioning method based on fusion trajectory extrapolation according to an embodiment of the present disclosure. As shown in Figure 12, in the positioning method of the embodiment of the present disclosure, unlike the three-base station positioning method adopted in the existing TOF solution, two base stations (i.e., the first ultra-wideband base station and the second ultra-wideband base station) are used for positioning.

[0110] Assume the coordinates of the first UWB base station are (x1, y1) and the coordinates of the second UWB base station are (x2, y2). Based on the flight time from the tag to the base stations, the distances d1 and d2 from the tag to the first and second UWB base stations are determined. Construct two circles with the two UWB base station locations as the center and radii d1 and d2 as the radius, respectively. The two circles intersect at two points. Finally, using dead reckoning technology, the tag's location can be determined at which of the two intersections is the "solved location" in Figure 12.

[0111] Since the two tag nodes cannot communicate with each other, it is also necessary to use a protocol to solve the competition problem caused by the first ultra-wideband base station and the second ultra-wideband base station needing to participate in the ranging of the two tag nodes at the same time. However, no matter what protocol is used, it will eventually lead to a decrease in the node ranging refresh rate, and the accuracy of tag ranging is related to the refresh rate. The decrease in refresh rate means an increase in positioning accuracy error. Through the embodiment of the present disclosure, during the positioning process based on trajectory calculation technology, the corresponding base station time window resources can be released to the tag that needs to increase the refresh rate or the tag to be located, thereby reducing the error caused by the low refresh rate to a certain extent.

[0112] Dead reckoning generally refers to a method of estimating a future arrival location, without any external reference, by using a known starting position combined with estimated speed and direction over time. Dead reckoning in the disclosed embodiments uses inertial sensors (i.e., accelerometers and gyroscopes) to estimate speed and direction, and then determines the estimated position through integral calculations. This method's error increases over time, so the timestamps for dead reckoning should not be too long.

[0113] FIG13 is a flow chart of a two-dimensional UWB positioning method according to an embodiment of the present disclosure. As shown in FIG13 , the method includes the following steps:

[0114] Step S1301: Initialize the UWB tag position.

[0115] When the user terminal enters a certain indoor scene, it is necessary to initialize the position of the UWB tag, obtain the initial position of the user terminal in the indoor scene, so as to facilitate the subsequent determination of the positioning information of the user terminal in the indoor scene.

[0116] Step S1302: Calculate the distances d1 and d2 between the UWB tag and two ultra-wideband base stations. The two-dimensional UWB positioning system sets the transceiver power levels of the ultra-wideband base station and the UWB tag in the user terminal according to the relationship between max(d1, d2) and the threshold d T ;

[0117] For example: when max(d1, d2) < d T1 , the power level is selected as pc1;

[0118] d T1 < max(d1, d2) < d T2 , the power level is selected as pc2;

[0119] d T2 < max(d1, d2) < dT3, the power level is selected as pc3.

[0120] In one embodiment, the transceiver power levels of the UWB tags in the ultra-wideband base station and the user terminal are the same.

[0121] Step S1303: Based on the moving speed of the user terminal and the TOF positioning accuracy requirement, and through debugging by the two-dimensional UWB positioning system, determine an appropriate tag refresh rate.

[0122] For example: when determining the number of tags that can be accommodated (i.e., the number of user terminals) n, in the case where the number of tags participating in positioning in the system is lower than the threshold n, increase the tag positioning refresh rate to improve the positioning accuracy; in the case where the number of tags participating in positioning in the system is higher than or equal to n, the refresh rate is not adjusted.

[0123] Step S1304: The first ultra-wideband base station and the second ultra-wideband base station respectively send the collected corresponding TOF time information (i.e., the first flight time information in the above embodiment) to the positioning server;

[0124] Step S1305: The sensor module of the user terminal collects the first auxiliary positioning information and synchronously uploads it to the positioning server.

[0125] Among them, the sensor module of the user terminal includes but is not limited to: an acceleration sensor, a gyroscope, etc., which are used to provide (first) auxiliary positioning information for the positioning of the user terminal, that is, acceleration information, the moving direction of the user terminal, pose position (i.e., the attitude information of the user terminal), etc. These auxiliary positioning information can help reduce the positioning error in positioning.

[0126] In step S1306, the positioning server calculates the positioning result of the user terminal based on the TOF time information, the first auxiliary positioning information and the initial position information of the user terminal through a TOF algorithm combined with trajectory calculation.

[0127] In one embodiment, the single-trip time of the UWB signal from the user terminal to the first ultra-wideband base station and the second ultra-wideband base station can be obtained from the TOF time information, which is recorded as t1 and t2 respectively; then the distance from the user terminal to the first ultra-wideband base station and the second ultra-wideband base station is obtained, that is, d1=c*t1, d2=c*t2, where c is the signal propagation speed in the air.

[0128] Assume the coordinates of the user terminal are (x, y), and establish an equation system:

[0129] (x-x1) 2 +(y-y1) 2 =d1 2 ;

[0130] (x-x2) 2 +(y-y2) 2 =d2 2 ,

[0131] The positioning result of the user terminal is determined by solving the equation group, combining the acceleration provided by the gyroscope and accelerometer, the movement direction information, the posture information of the user terminal, and the initial position of the user terminal.

[0132] Based on the above equations, two positioning results can be obtained. However, the positioning results are unique, so the two positioning results need to be further screened. This screening includes:

[0133] The motion trajectory of the user terminal can be determined through the acceleration information, moving direction, and posture information of the user terminal; based on the motion trajectory and the initial position of the user terminal, the final accurate positioning result (i.e., the first positioning information) is screened out from the two positioning results.

[0134] Step S1307: The server returns the positioning result to the user terminal or display device via the wireless transmission network;

[0135] In this embodiment, wireless network support is required, and the positioning information needs to be uploaded to the positioning server via the wireless network for positioning information processing, and then the positioning result is returned to the positioning result display device.

[0136] Step S1308: Based on the positioning result determined in step S1306, positioning is performed only by using the user terminal's own sensor trajectory estimation method during the next ΔT time.

[0137] Among them, ΔT is an integer multiple of the base station time window occupied by a tag positioning. Since the trajectory is obtained through time-velocity integration, the size of ΔT will affect the positioning accuracy. The larger ΔT is, the greater the integral error is. We finally set the ΔT value that meets the user terminal positioning accuracy through system debugging.

[0138] During the ΔT period, the user terminal does not need the base station positioning signal for positioning. The user terminal can release the base station positioning window resources occupied by the TOF algorithm, and the base station can allocate the resources released by the user terminal to other user terminals queuing for positioning.

[0139] Step S1309: After the dead reckoning positioning in the ΔT period is completed, the user terminal resumes TOF+dead reckoning fusion positioning and reallocates the base station positioning resources to the user terminal.

[0140] This disclosure primarily addresses the issues of redundant positioning base stations, low system capacity, and endurance of user terminal tags in current mainstream positioning solutions. Since TDOA system tags only send positioning messages in a single trip and do not receive them, collaborative positioning is difficult to implement and requires multiple positioning base stations, typically requiring four base stations to complete positioning. Therefore, this disclosure utilizes a TOF positioning method, alternating between dead reckoning positioning (which does not occupy base station resources) and TOF+dead reckoning fusion positioning (which does). This method ensures positioning accuracy while also expanding system capacity.

[0141] The methods and devices in the above embodiments of the present disclosure can be applied to smart factories and smart cities. A UWB communication device is set at each physical entrance of a specific UWB two-dimensional positioning space. When a tag enters the system, the UWB communication device assigns the location coordinates of the current physical entrance to the tag as the initial tag position. The tag is then connected to the two-dimensional UWB positioning system in the embodiments of the present disclosure, and the method of the embodiments of the present disclosure is run to determine the location of the user terminal.

[0142] The above-mentioned embodiments of the present disclosure can be used for positioning mobile user terminals such as mobile phones, electronic watches, and smart robots. Currently, smart phones and watches have GPS positioning functions, but the GPS positioning effect is not ideal for indoor positioning. When the user terminal enters the indoor environment, the user terminal will use the built-in gyroscope, acceleration sensor, etc. to perform trajectory calculation, and can estimate the approximate position. Combined with the two ultra-wideband base stations in the two-dimensional UWB positioning system of the present disclosure, the user terminal can be accurately positioned. In this way, the initial position of the user terminal entering the two-dimensional UWB positioning system in the embodiment of the present disclosure can be determined. Subsequently, the method of the embodiment of the present disclosure can be run to determine the position of mobile user terminals such as mobile phones, electronic watches, and smart robots.

[0143] An embodiment of the present disclosure further provides a computer-readable storage medium, in which a computer program is stored. The computer program is configured to execute the steps of any one of the above method embodiments when run.

[0144] In an exemplary embodiment, the computer-readable storage medium may include, but is not limited to, various media that can store computer programs, such as a USB flash drive, a read-only memory (ROM), a random access memory (RAM), a mobile hard disk, a magnetic disk, or an optical disk.

[0145] An embodiment of the present disclosure further provides an electronic device, including a memory and a processor, wherein the memory stores a computer program, and the processor is configured to run the computer program to perform the steps in any one of the above method embodiments.

[0146] In an exemplary embodiment, the electronic device may further include a transmission device and an input / output device, wherein the transmission device is connected to the processor, and the input / output device is connected to the processor.

[0147] For specific examples in this embodiment, reference may be made to the examples described in the above embodiments and exemplary implementation modes, and this embodiment will not be described in detail here.

[0148] Obviously, those skilled in the art should understand that the modules or steps of the present disclosure described above can be implemented using a general-purpose computing device, they can be concentrated on a single computing device, or distributed across a network composed of multiple computing devices, they can be implemented using program code executable by the computing device, and thus, they can be stored in a storage device and executed by the computing device, and in some cases, the steps shown or described can be performed in a different order than herein, or they can be fabricated into separate integrated circuit modules, or multiple modules or steps can be fabricated into a single integrated circuit module for implementation. Thus, the present disclosure is not limited to any particular combination of hardware and software.

[0149] The above description is merely a preferred embodiment of the present disclosure and is not intended to limit the present disclosure. Those skilled in the art will readily appreciate that the present disclosure is susceptible to various modifications and variations. Any modifications, equivalent substitutions, or improvements made within the principles of the present disclosure shall be within the scope of protection of the present disclosure.

Claims

1. An ultra-wideband positioning method, applied to a positioning server, comprising: Determine first positioning information after the user terminal moves according to initial position information before the user terminal moves, first flight time information reported by the ultra-wideband base station, and first auxiliary positioning information reported during the movement of the user terminal; Determine second positioning information of the user terminal within a preset time interval after receiving the first positioning information according to the first positioning information and second auxiliary positioning information reported by the user terminal.

2. The method according to claim 1, wherein: The user terminal is provided with an ultra-wideband tag.

3. The method according to claim 1, wherein: The ultra-wideband base station includes a first ultra-wideband base station and a second ultra-wideband base station.

4. The method according to claim 1, wherein: Determining second positioning information of the user terminal within a preset time interval after receiving the first positioning information includes: Determine the movement speed and movement direction of the user terminal within the preset time interval by using the second auxiliary positioning information, and obtain a speed calculation result and a direction calculation result; The second positioning information is determined by combining the speed calculation result, the direction calculation result and the first positioning information.

5. An ultra-wideband positioning method, applied to a user terminal, comprising: Reporting the initial position information before the movement and the first auxiliary positioning information during the movement to the positioning server, and receiving the first positioning information returned by the positioning server, wherein the first positioning information is determined based on the initial position information, the first auxiliary positioning information and the first flight time information reported by the ultra-wideband base station; Within a preset time interval after receiving the first positioning information, second auxiliary positioning information is reported to the positioning server, and second positioning information returned by the positioning server is received, wherein the second positioning information is determined based on the first positioning information and the second auxiliary positioning information.

6. The method according to claim 5, wherein: The ultra-wideband base station includes a first ultra-wideband base station and a second ultra-wideband base station.

7. The method according to claim 6, wherein: Before reporting the initial position information before the movement and the first auxiliary positioning information during the movement to the positioning server, the method further includes: Determine a first distance value between the user terminal and the first ultra-wideband base station, and a second distance value between the user terminal and the second ultra-wideband base station; Comparing the larger distance value of the first distance value and the second distance value with a preset distance threshold, and setting a transmit and receive power level based on the comparison result; Based on the receiving and transmitting power level, positioning signals are exchanged with the first ultra-wideband base station and the second ultra-wideband.

8. The method according to claim 5, wherein: The first auxiliary positioning information or the second auxiliary positioning information includes at least one of the following: direction information of the user terminal, acceleration direction information of the user terminal, and posture information of the user terminal.

9. The method according to claim 5, wherein: After receiving the first positioning information returned by the positioning server, the method further includes: The occupied base station positioning window resources of the ultra-wideband base station are released, wherein the base station positioning window resources are used for positioning information interaction between the user terminal and the ultra-wideband base station.

10. The method according to claim 5, wherein: The method further comprises: The frequency of positioning information interaction between the user terminal and the ultra-wideband base station is determined according to the moving speed and positioning accuracy requirements of the user terminal; wherein the positioning information interaction is used for the ultra-wideband base station to obtain the flight time.

11. A positioning server, comprising: A first positioning module, configured to determine first positioning information of the user terminal after the user terminal moves according to initial position information of the user terminal before the user terminal moves, first flight time information reported by the ultra-wideband base station, and first auxiliary positioning information reported during the movement of the user terminal; The second positioning module is configured to determine second positioning information of the user terminal within a preset time interval after receiving the first positioning information according to the first positioning information and the second auxiliary positioning information reported by the user terminal.

12. A user terminal, comprising: A first reporting module, configured to report the initial position information before moving and the first auxiliary positioning information during the moving process to the positioning server; A first receiving module is configured to receive first positioning information returned by the positioning server, wherein the first positioning information is determined based on the initial position information, the first auxiliary positioning information, and first flight time information reported by an ultra-wideband base station; A second reporting module, configured to report second auxiliary positioning information to the positioning server within a preset time interval after receiving the first positioning information; The second receiving module is configured to receive second positioning information returned by the positioning server, wherein the second positioning information is determined based on the first positioning information and the second auxiliary positioning information.

13. A computer-readable storage medium having a computer program stored therein, wherein: When the computer program is executed by a processor, the computer program implements the steps of the method described in any one of claims 1 to 4, or implements the steps of the method described in any one of claims 5 to 10.

14. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the method described in any one of claims 1 to 4, or implements the steps of the method described in any one of claims 5 to 10 when executing the computer program.

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