Ultra-wideband positioning method, positioning server and user terminal

Abstract

The embodiment of the invention provides an ultra-wideband positioning method, a positioning server and a user terminal. The method comprises the following steps: determining first positioning information after a user terminal moves according to initial position information before the user terminal moves, first flight time information reported by an ultra-wideband base station and first auxiliary positioning information reported in the moving process of the user terminal; and determining second positioning information within a preset time interval after the user terminal receives the first positioning information according to the first positioning information and second auxiliary positioning information reported by the user terminal. According to the invention, the problem of high deployment cost of the UWB base station in the prior art is solved, and the effect of improving the positioning precision is achieved.

Description

Technical Field

[0001] Embodiments of the present invention relate to the field of communications, and more particularly, to an ultra-wideband positioning method, a positioning server, and a user terminal. Background Art

[0002] For outdoor open environments, satellite positioning technology can achieve positioning accuracy at the sub-meter level or even centimeter level. However, satellite positioning is subject to the influence of signal strength and is extremely vulnerable to signal interference such as occlusion and multipath effects. In urban canyons with high-rise buildings or enclosed indoor environments, satellite positioning is inaccurate or even unavailable. To meet the indoor positioning requirements such as material search, indoor intelligent robots, shopping mall navigation and shopping guide, and emergency evacuation, as well as to solve the "last kilometer" problem that cannot be covered by outdoor navigation, indoor positioning has become a hot research topic for research institutions and related enterprises.

[0003] UWB (Ultra Wide Band) technology combines many advantages such as 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 - 30 cm, and up to 10 cm at most. The measurable range can reach 100 m, which is much higher than indoor positioning technologies such as WIFI and Bluetooth; moreover, the UWB positioning frequency band can also be compatible with WIFI, Bluetooth, and 5G frequency bands. However, existing UWB positioning solutions require the deployment of more than two base stations, with high deployment costs, and clock synchronization is required between multiple base stations to ensure the accuracy of time difference. Therefore, how to reduce the cost of UWB has become a bottleneck in the development of UWB. Summary of the Invention

[0004] Embodiments of the present invention provide an ultra-wideband positioning method, a positioning server, and a user terminal to at least solve the problem of high deployment cost of UWB base stations in related technologies.

[0005] According to an embodiment of the present invention, an ultra-wideband positioning method is provided, which is applied to a positioning server and includes: determining first positioning information of the user terminal after movement according to initial position information before the user terminal moves, first time-of-flight information reported by an ultra-wideband base station, and first auxiliary positioning information reported during the movement of the user terminal; determining 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.

[0006] According to another embodiment of the present invention, there is provided an ultra-wideband positioning method, which is applied to a user terminal and includes: reporting the initial position information before movement and the first auxiliary positioning information during movement to a positioning server, and receiving the first positioning information returned by the positioning server, where the first positioning information is determined based on the initial position information, the first auxiliary positioning information, and the first time-of-flight information reported by an ultra-wideband base station; reporting the second auxiliary positioning information to the positioning server within a preset time interval after receiving the first positioning information, and receiving the second positioning information returned by the positioning server, where the second positioning information is determined based on the first positioning information and the second auxiliary positioning information.

[0007] According to yet another embodiment of the present invention, there is provided a positioning server, including: a first positioning module, configured to determine the first positioning information after the movement of the user terminal according to the initial position information before the movement of the user terminal, the first time-of-flight information reported by the ultra-wideband base station, and the first auxiliary positioning information reported during the movement of the user terminal; a second positioning module, configured to determine the 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.

[0008] According to yet another embodiment of the present invention, there is provided a user terminal, including: a first reporting module, configured to report the initial position information before movement and the first auxiliary positioning information during movement to a positioning server; a first receiving module, configured to receive the first positioning information returned by the positioning server, where the first positioning information is determined based on the initial position information, the first auxiliary positioning information, and the first time-of-flight information reported by the ultra-wideband base station; a second reporting module, configured to report the second auxiliary positioning information to the positioning server within a preset time interval after receiving the first positioning information; a second receiving module, configured to receive the second positioning information returned by the positioning server, where the second positioning information is determined based on the first positioning information and the second auxiliary positioning information.

[0009] According to yet another embodiment of the present invention, there is also provided a computer-readable storage medium, in which a computer program is stored, where the computer program is configured to execute the steps in any one of the above method embodiments when running.

[0010] According to yet another embodiment of the present invention, there is also provided an electronic device, including a memory and a processor, where a computer program is stored in the memory, and the processor is configured to run the computer program to execute the steps in any one of the above method embodiments.

[0011] Through the above embodiments of the present invention, 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 without relying on the base station reporting information, and only needs to combine the first positioning information with the second auxiliary positioning information reported by the user terminal. By the above method, the number of base stations required for positioning can be reduced while ensuring the positioning accuracy. Therefore, the problem of high deployment cost of UWB base stations in the related art can be solved, and the effect of improving the positioning accuracy can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 is a block diagram of the hardware structure of a mobile terminal for implementing the ultra-wideband positioning method according to an embodiment of the present invention;

[0013] Figure 2 is a block diagram of the structure of a two-dimensional UWB positioning system according to an embodiment of the present invention;

[0014] Figure 3 is a block diagram of the structure of a mobile terminal according to an embodiment of the present invention;

[0015] Figure 4 is a flowchart of an ultra-wideband positioning method according to an embodiment of the present invention;

[0016] Figure 5 is a flowchart of an ultra-wideband positioning method according to another embodiment of the present invention;

[0017] Figure 6 is a block diagram of the structure of a positioning server according to an embodiment of the present invention;

[0018] Figure 7 is a block diagram of the structure of a user terminal according to an embodiment of the present invention;

[0019] Figure 8 is a schematic diagram of a positioning method based on TOF according to an embodiment of the present invention;

[0020] Figure 9 is a schematic diagram of the positioning principle of an unknown point according to an embodiment of the present invention;

[0021] Figure 10 is a schematic diagram of a positioning method based on TDOA according to an embodiment of the present invention;

[0022] Figure 11 is a schematic diagram of TOF measurement between a tag and a base station according to an embodiment of the present invention;

[0023] Figure 12 is a schematic diagram of a positioning method integrating trajectory inference according to an embodiment of the present invention;

[0024] Figure 13 is a flowchart of a two-dimensional UWB positioning method according to an embodiment of the present invention. Detailed implementation manners

[0025] In the following, embodiments of the present invention will be described in detail with reference to the accompanying drawings and in conjunction with the embodiments.

[0026] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and do not necessarily have to be used to describe a specific order or sequence.

[0027] The method embodiments provided in the embodiments of the present application can be executed on 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 for implementing the ultra-wideband positioning method of the embodiments of the present invention. As Figure 1 shown, the mobile terminal may include one or more ( Figure 1 only one is shown in Figure 1 a) processor 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. Among them, the above-mentioned mobile terminal may further include a transmission device 106 for communication functions and an input / output device 108. Those of ordinary skill in the art can understand that Figure 1 the structure shown in Figure 1 is only schematic and does not limit the structure of the above-mentioned mobile terminal. For example, the mobile terminal may further include more or fewer components than

[0028] shown in

[0029] shown, or have a different configuration from Figure 1 shown.

[0028] The memory 104 can be used to store computer programs. For example, 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 invention. The processor 102 executes various functional applications and data processing by running the computer program stored in the memory 104, that is, implements the above-mentioned method. The memory 104 may include a high-speed random access memory, and may also include a non-volatile memory, such as one or more magnetic storage devices, flash memories, or other non-volatile solid-state memories. In some instances, the memory 104 may further include a memory remotely disposed relative to the processor 102, and these remote memories may be connected to the mobile terminal through a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an enterprise intranet, a local area network, a mobile communication network, and combinations thereof.

[0029] The transmission device 106 is used to receive or send data via a network. Specific examples of the above network may include a wireless network provided by a communication provider of a mobile terminal. In one example, the transmission device 106 includes a network adapter (Network Interface Controller, abbreviated as NIC), which can be connected to other network devices through a base station so as to communicate with the Internet. In one example, the transmission device 106 can be a Radio Frequency (RF) module, which is used to communicate with the Internet wirelessly.

[0030] Embodiments of this application can run on Figure 2 the two-dimensional UWB positioning system shown, such as Figure 2 shown, this 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.

[0031] The mobile terminal 10 interacts with the ultra-wideband base station 20 for positioning signals, initializes tags and positioning base stations according to the adopted algorithm, and enters the normal positioning process; among them, the ultra-wideband base station 20 includes a first ultra-wideband base station 21 and a second ultra-wideband base station 22.

[0032] The ultra-wideband base station 20 connects the wireless communication module 30 with the backend server of the positioning server 40 through a wireless communication network, and uploads the time or time difference of the tag emission signal received by the ultra-wideband base station 20 to the positioning server 40 for position calculation.

[0033] The wireless communication module 30 is an intermediary between the ultra-wideband base station 20 and the backend server of the positioning server 40.

[0034] The positioning server 40 is used to process the positioning information sent from the ultra-wideband base station 20 and the mobile terminal 10, parse it according to the corresponding algorithm, and finally return the positioning result.

[0035] The display device 50 can be the mobile terminal 10 itself, and combines the corresponding graphical interface and map software to display the current position of the mobile device.

[0036] Such as Figure 3 shown, the mobile terminal 10 includes a positioning module 11, among which, 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.

[0037] The power management module 111 is used to provide power for tag transmission and reception;

[0038] Program module 112 is used to generate the positioning signal of the mobile terminal, process 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.

[0039] For example: when max(d1, d2) < d T1 the power level is selected as pc1;

[0040] When d T1 < max(d1, d2) < d T2 the power level is selected as pc2;

[0041] When d T2 < max(d1, d2) < d T3 the power level is selected as pc3, where max() is the maximum value function used to select the maximum value from d1 and d2, and d T1 d T2 d T3 are respectively preset thresholds.

[0042] The sensor module 113 includes a gyroscope and an acceleration sensor. The moving direction and acceleration information of the mobile terminal 10 are identified through the gyroscope and the acceleration sensor. Further, according to the identified moving direction and acceleration information, the pose information of the mobile terminal 10 can be determined, and the moving direction, acceleration information, and pose information are uploaded to the positioning server in real time for the trajectory calculation of the tag.

[0043] The UWB tag 114 is used to transmit and receive UWB signals.

[0044] In this embodiment, an ultra-wideband positioning method running on the above mobile terminal or two-dimensional UWB positioning system is provided. Specifically, it is applied to the positioning server 40. Figure 4 is the flowchart of the ultra-wideband positioning method according to the embodiment of the present invention. This method is applied to the positioning server, as Figure 4 shown, and this process includes the following steps:

[0045] Step S402: Determine the first positioning information of the user terminal after movement according to the initial position information of the user terminal before movement, the first time-of-flight information reported by the ultra-wideband base station, and the first auxiliary positioning information reported during the movement of the user terminal; where the user terminal is equivalent to the above mobile terminal 10.

[0046] In this embodiment, an ultra-wideband tag (i.e., UWB tag) is set in the user terminal; the ultra-wideband base station includes a first ultra-wideband base station and a second ultra-wideband base station.

[0047] In one embodiment, determining the first positioning information includes:

[0048] UWB signals respectively sent by the user terminal to the first ultra-wideband base station and the second ultra-wideband base station;

[0049] After receiving the UWB signals, the first ultra-wideband base station and the second ultra-wideband base station report first time-of-flight information to the positioning server 40. Among them, the first time-of-flight 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 time-of-flight 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;

[0050] 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 according to the obtained t1 and t2; and then based on d1, d2, the position of the first ultra-wideband base station, and the position of the second ultra-wideband base station, a set of binary quadratic equations is established and solved;

[0051] The positioning server determines the first positioning information from the solutions of the binary quadratic equations based on the solutions of the binary quadratic equations (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. Among them, the first auxiliary positioning information is information such as the moving direction, acceleration information, and pose information collected by the sensor module of the user terminal.

[0052] In this embodiment, the TOF method combined with the dead reckoning positioning method is used. In this method, the dead reckoning method can make up for the deficiency of the reduced positioning accuracy caused by reducing the number of ultra-wideband base stations. Therefore, only two ultra-wideband base stations can be set to achieve precise positioning of the terminal, so as to achieve high-precision positioning and effectively reduce the deployment cost of the base stations.

[0053] In this embodiment, the first auxiliary positioning information is collected and reported by the above-mentioned sensor module 113.

[0054] Step S404, determine the 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.

[0055] In one embodiment, after determining the first positioning information, the positioning information of the user terminal within the subsequent preset time interval is the second positioning information, and the second positioning information is determined only by the module of the user terminal through trajectory inference. Specifically, determining the second positioning information includes:

[0056] Determine the second positioning information based on the first positioning information, in combination with the moving direction, acceleration information, and pose information of the user terminal reported by the sensor module of the user terminal within the preset time interval.

[0057] In step S404 of this embodiment, determining the second positioning information of the user terminal within the preset time interval after receiving the first positioning information includes: determining the movement speed and movement direction of the user terminal within the preset time interval through the second auxiliary positioning information to obtain a speed estimation result and a direction estimation result; determining the second positioning information in combination with the speed estimation result, the direction estimation result, and the first positioning information.

[0058] In one embodiment, after determining the second positioning information of the user terminal within the preset time interval after receiving the first positioning information, that is, after the trajectory estimation positioning ends, restore the TOF method combined with the trajectory estimation fusion positioning method, and reallocate the base station positioning resources to the terminal, that is, determine the third positioning information of the user terminal according to the third auxiliary positioning information reported by the terminal, the second time-of-flight information reported by the ultra-wideband base station, and the second positioning information. Such a trajectory estimation positioning method that does not occupy base station resources and the positioning method of combining the TOF method that occupies base station resources with trajectory estimation work alternately, which not only ensures the positioning accuracy but also expands the system capacity.

[0059] In this embodiment, both the second auxiliary positioning information and the third auxiliary positioning information are collected and reported by the above-mentioned sensor module 113.

[0060] Through the above steps, within the preset time interval after receiving the first positioning information, the positioning server can obtain the positioning information of the user terminal in real time without relying on the information reported by the base station. Only by combining the first positioning information with the second auxiliary positioning information reported by the user terminal. By the above method, while reducing the number of base stations required for positioning, the positioning accuracy can be ensured. Therefore, the problem of high deployment cost of UWB base stations in the related technology can be solved, and the effect of improving the positioning accuracy can be achieved.

[0061] The embodiment of the present invention further provides an ultra-wideband positioning method, which is applied to a user terminal. Figure 5 It is a flowchart of an ultra-wideband positioning method according to another embodiment of the present invention, which is applied to a user terminal, that is, a mobile terminal 10, as Figure 5 shown, and the method includes the following steps:

[0062] 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, where the first positioning information is determined based on the initial position information, the first auxiliary positioning information, and the first time-of-flight information reported by the ultra-wideband base station.

[0063] In one embodiment, the ultra-wideband base station includes a first ultra-wideband base station and a second ultra-wideband base station.

[0064] 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 between 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; and performing positioning signal interaction with the first ultra-wideband base station and the second ultra-wideband base station based on the transceiver power level.

[0065] By comparing the larger distance value between the first distance value and the second distance value with the preset distance threshold and setting the transceiver power level based on the comparison result, the user terminal and the ultra-wideband base station can perform information interaction with a suitable transceiver power level. For example, when the larger distance value is less than or equal to the preset distance threshold, information interaction can be performed with a smaller transceiver power level; when the larger distance value is greater than the preset distance threshold, the transceiver power level can be increased for information interaction. In this way, the power consumption of the device can be saved.

[0066] In one embodiment, the first auxiliary positioning information or the second auxiliary positioning information includes at least one of the following: the direction information of the user terminal, the acceleration direction information of the user terminal, and the pose information of the user terminal. Among them, the pose information is the current posture of the user terminal, which is convenient for the positioning server to more accurately determine the positioning information of the user terminal.

[0067] In one embodiment, the first auxiliary positioning information and the second auxiliary positioning information include at least one of the following: the direction information of the user terminal, the acceleration direction information of the user terminal, and the pose information of the user terminal.

[0068] In step S502 of this embodiment, after receiving the first positioning information returned by the positioning server, the method further includes: releasing the base station positioning window resources occupied by the ultra-wideband base station, where the base station positioning window resources are used for positioning information interaction between the user terminal and the ultra-wideband base station.

[0069] When there are a large number of user terminals, after a part of the user terminals determine the first positioning information, dead reckoning positioning is used instead of TOF, which can release the occupation of the positioning base station resources, and thus relieve the base station resource pressure.

[0070] Step S504: Report second auxiliary positioning information to the positioning server within a preset time interval after receiving the first positioning information, and receive the second positioning information returned by the positioning server, where the second positioning information is determined based on the first positioning information and the second auxiliary positioning information.

[0071] In one embodiment, the method further includes: determining the frequency of positioning information interaction (i.e., tag refresh rate) between the user terminal and the ultra-wideband base station according to the moving speed and positioning accuracy requirement of the user terminal; where the positioning information interaction is used for the ultra-wideband base station to obtain the time of flight.

[0072] Different tag refresh rates correspond to different positioning accuracies. Therefore, the tag refresh rate can be determined according to the positioning accuracy requirement, so as to meet the TOF positioning accuracy requirement with an appropriate tag refresh rate.

[0073] For example: determine the threshold n of the number of tags (number of user terminals) that can be accommodated. When 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. When the number of positioning tags is greater than or equal to n, the refresh rate remains unchanged.

[0074] Through the description of the above embodiments, those skilled in the art can clearly understand that the method according to the above embodiments can be implemented by means of software plus a necessary general hardware platform. Of course, it can also be implemented by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. The computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disc), and includes several instructions for causing a terminal device (which can be a mobile phone, a computer, a server, or a network device, etc.) to execute the methods described in various embodiments of the present invention.

[0075] In this embodiment, a positioning server and a user terminal are further provided. The positioning server and the user terminal are used to implement the above embodiments and preferred implementation manners, and those that have been described will not be repeated. As used below, the term "module" can be a combination of software and / or hardware that realizes a predetermined function. Although the devices described in the following embodiments are preferably implemented in software, implementation in hardware, or a combination of software and hardware is also possible and contemplated.

[0076] Figure 6is a structural block diagram of a positioning server according to an embodiment of the present invention, as shown in Figure 6 As shown, the positioning server 40 includes: a first positioning module 41 and a second positioning module 42.

[0077] The first positioning module 41 is configured to determine the first positioning information of the user terminal after movement according to the initial position information before the user terminal moves, the first time-of-flight information reported by the ultra-wideband base station, and the first auxiliary positioning information reported during the movement of the user terminal;

[0078] The second positioning module 42 is configured to determine the 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.

[0079] Figure 7 is a structural block diagram of a user terminal according to an embodiment of the present invention, as shown in Figure 7 As shown, 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.

[0080] The first reporting module 71 is configured to report the initial position information before movement and the first auxiliary positioning information during movement to the positioning server;

[0081] The first receiving module 72 is configured to receive the first positioning information returned by the positioning server, where the first positioning information is determined based on the initial position information, the first auxiliary positioning information, and the first time-of-flight information reported by the ultra-wideband base station;

[0082] The second reporting module 73 is configured to report the second auxiliary positioning information to the positioning server within a preset time interval after receiving the first positioning information;

[0083] The second receiving module 74 is configured to receive the second positioning information returned by the positioning server, where the second positioning information is determined based on the first positioning information and the second auxiliary positioning information.

[0084] This 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, and the UWB tag 114 in the above embodiment functionally includes the functions of the first receiving module 72 and the second receiving module 74.

[0085] It should be noted that the above-mentioned modules can be implemented by software or hardware. For the latter, it can be achieved in the following ways, but not limited to: the above-mentioned modules are all located in the same processor; or, the above-mentioned modules are separately located in different processors in any combination form.

[0086] Compared with indoor positioning technologies such as BLE (Bluetooth Low Energy) and WiFi, UWB (UltraWide Band) positioning has the advantages of low power consumption, strong anti-interference ability with large bandwidth, anti-multipath loss, and high positioning accuracy.

[0087] Different from most wireless technologies, UWB positioning works through impulse radio, such as using a series of pulses on a wide frequency band. Compared with satellites, WiFi, and Bluetooth that use modulated sine waves to transmit information on a narrow frequency band, UWB pulses have the following characteristics:

[0088] 1. Use non-sinusoidal narrow pulses from nanoseconds to microseconds to transmit data, which can be recognized even in a noisy channel environment.

[0089] 2. Compared with other technologies such as WiFi or BLE, for ToF ranging, UWB pulses are more suitable for dense multipath environments. Due to the extremely high operating frequency and extremely low duty cycle, they have high resolution. The multipath signals of narrow pulses are not easily overlapped in time, and the radio signals arriving at the receiver through multiple paths can be easily separated in the IR-UWB system.

[0090] The working frequency band coverage range of UWB technology is a total of 7G frequency bands from 3 - 5G and 6G - 10G, far away from the busy ISM frequency band concentrated around 2.4GHz; among them, the UWB pulses used for positioning and ranging work in the frequency range between 6.5 - 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.

[0091] Common UWB positioning solutions include TOF (Time of Flight), TDOA (Time Difference of Arrival), and AOA (Angle of Arrival). Each of these three solutions has its own limitations. The following is a simple introduction to the TOF solution and the TDOA solution.

[0092] TOF solution:

[0093] The TOF-based positioning algorithm, which uses the time difference of flight for ranging, generally belongs to the two-way ranging technology (Two Way Ranging). Specifically, it measures the distance between nodes by using the time for the signal to travel back and forth between two asynchronous transceivers.

[0094] For example: As Figure 8 shown, the time interval from when the reference point emits a signal to when it receives a response is denoted as t roundA , and the time interval from when the unknown point receives a data packet to when it sends a response is denoted as t replyB . Then the one-way flight time of the signal in the air is (t roundA - t replyB ) / 2. By multiplying the propagation speed of electromagnetic waves in the air by the time, the distance between the reference point and the unknown point can be obtained.

[0095] Another example: As Figure 9 shown, circles are drawn based on the distances from multiple reference points to the unknown point, and the intersection point is the position of the unknown point.

[0096] Since this TOF positioning method requires the base station and the tag to communicate back and forth, it will increase the power consumption and the battery life will be relatively short. In addition, the number of UWB wireless signals that can be accommodated in the UWB channel at the same time is certain, and the number of UWB wireless signals consumed by a single TOF positioning is large, which will generally result in a general concurrency of the tags as a whole.

[0097] TDOA scheme:

[0098] The TDOA-based positioning algorithm first synchronizes the clocks among all reference points. Then the unknown point sends a signal, and different reference points receive the signal at different times. A certain reference point's time of receiving the signal is selected as the reference, and the time when other reference points receive the signal minus this reference gives the time difference of arrival of the positioning signal. Based on the TDOA values between the unknown point and two reference points, a hyperbola can be established. At least three reference points are required to establish a set of hyperbola equations to solve for the position estimate of the unknown point, as Figure 10 shown.

[0099] The TDOA positioning scheme requires more reference base stations, resulting in a high deployment cost. At the same time, each base station needs to be clock-synchronized to ensure the accuracy of the time difference of arrival among multiple base stations. Since the tag only sends positioning messages without receiving, it is difficult to achieve data aggregation and cooperative positioning.

[0100] Table 1 shows the comparison of three UWB positioning algorithms in various wireless positioning metrics. Among them, the wireless positioning metrics include: positioning accuracy, environmental adaptability, power consumption, scale, base station density, and cost.

[0101] Table 1

[0102]

[0103] The embodiments of the present invention are used for positioning devices such as mobile terminals (i.e., user terminals in the above embodiments), to solve the problems of redundant positioning base stations, low system capacity (i.e., low number of locatable tags), and battery life of terminal tags in current mainstream positioning solutions. According to the usage status of the mobile terminal and the number of system devices, the tag refresh rate is appropriately adjusted, and multiple positioning algorithms are flexibly integrated. Without affecting the positioning accuracy, the problem of high base station deployment cost in UWB indoor positioning is solved, the number of base stations used in the positioning process of the positioning tag is reduced, and while ensuring accurate positioning, the number of tags that the system can accommodate is increased, and the system power consumption is reduced.

[0104] Since the TDOA system tag only sends positioning messages in one-way and does not receive, it is difficult to achieve cooperative positioning, and a large number of positioning base stations are required. Generally, four base stations are required to complete positioning. Therefore, the TOF positioning method is adopted in the embodiments of the present invention. However, as described 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, in each embodiment of the present invention, the trajectory prediction technology is adopted to replace TOF with trajectory prediction positioning within a certain time interval ΔT, releasing the occupation of positioning base station resources, alleviating the base station resource pressure in the case of a large number of system positioning tags, and at the same time, the trajectory prediction combined with the TOF method ensures the accuracy of positioning to a certain extent.

[0105] In practical applications, since all tags and base stations share the channel, the TOF between the tag and each base station must be measured sequentially. As Figure 11 shown, if the position of the node moves rapidly during the round-trip ranging with each base station, a large deviation will occur in the positioning. By integrating the trajectory prediction technology, the positioning error can be minimized as much as possible.

[0106] Figure 12 is a schematic diagram of the positioning method integrating trajectory prediction according to the embodiments of the present invention. As Figure 12 shown, in the positioning method of the embodiments of the present invention, different from the three-base-station positioning method adopted in the existing TOF scheme, two base stations (i.e., the first ultra-wideband base station and the second ultra-wideband base station) are used for positioning.

[0107] If the coordinates of the first UWB base station are (x1, y1) and the coordinates of the second UWB base station are (x2, y2), then the distances d1 and d2 from the tag to the first and second UWB base stations are determined based on the flight time from the tag to the base station. Draw two circles with the two UWB base station locations as the center and d1 and d2 as the radius, respectively. The two circles intersect at two points. Finally, the trajectory calculation technology is combined to determine which of the two intersections is the tag location (i.e. Figure 12 Calculated Position in .

[0108] Since the two tag nodes cannot communicate with each other, it is also necessary 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 through a protocol. However, no matter what protocol is used, it will eventually lead to a reduction in the refresh rate of node ranging, and the accuracy of tag ranging is related to the refresh rate. A reduction in the refresh rate means an increase in the positioning accuracy error. Through the embodiments of the present invention, in the process of positioning based on trajectory calculation technology, the corresponding base station time window resources can be released to the tags that need to increase the refresh rate or the tags to be located, thereby reducing the error caused by the low refresh rate to a certain extent.

[0109] Trajectory dead reckoning generally refers to a method of estimating the future arrival position by using a known starting position combined with the estimated moving speed and heading over time without any external reference. Trajectory dead reckoning in the embodiments of the present invention uses inertial sensing (i.e., acceleration sensor, gyroscope sensor) to estimate speed and direction, and then determines the estimated position by integral calculation. The error of this method will increase with time, so the timestamp of trajectory dead reckoning should not be too long.

[0110] Figure 13 Flow chart of the two-dimensional UWB positioning method according to an embodiment of the present invention. Figure 13 As shown, the method comprises the following steps:

[0111] Step S1301, initializing the UWB tag position.

[0112] When a user terminal enters an indoor scene, it is necessary to initialize the UWB tag position and obtain the initial position of the user terminal in the indoor scene to facilitate the subsequent determination of the positioning information of the user terminal in the indoor scene.

[0113] Step S1302, calculate the distances d1 and d2 between the UWB tag and the two ultra-wideband base stations. The two-dimensional UWB positioning system calculates the distances d1 and d2 between the UWB tag and the two ultra-wideband base stations according to max(d1, d2) and the threshold d T The relationship between the UWB tags in the ultra-wideband base station and the user terminal is used to set the transmit and receive power levels;

[0114] For example: when max(d1,d2) <d T1When the time is up, select power level pc1;

[0115] d T1 <max(d1, d2) < d T2 , select power level pc2;

[0116] d T2 <max(d1, d2) < dT3, select power level pc3.

[0117] In one embodiment, the transceiver power levels of the UWB tags in the ultra-wideband base station and the user terminal are the same.

[0118] 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.

[0119] 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 remains unchanged.

[0120] 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 time-of-flight information in the above embodiment) to the positioning server;

[0121] Step S1305: The sensor module of the user terminal collects the first auxiliary positioning information and synchronously uploads it to the positioning server.

[0122] 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.

[0123] Step S1306: The positioning server calculates the positioning result of the user terminal through the TOF algorithm combined with dead reckoning based on the TOF time information, the first auxiliary positioning information, and the initial position information of the user terminal.

[0124] Specifically, the one-way 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, denoted as t1 and t2 respectively; then the distances from the user terminal to the first ultra-wideband base station and the second ultra-wideband base station are obtained, that is, d1 = c * t1, d2 = c * t2, where c is the signal propagation speed in the air.

[0125] Let the coordinates of the user terminal be (x, y), and a system of equations is established accordingly:

[0126] (x - x1) 2 +(y - y1) 2 = d1 2 ;

[0127] (x - x2) 2 +(y - y2) 2 = d2 2 ,

[0128] Based on the solutions of this system of equations, combined with the acceleration, moving direction information, attitude information of the user terminal provided by the gyroscope and acceleration sensor, and the initial position of the user terminal, the positioning result of the user terminal is determined.

[0129] Based on the above system of equations, two positioning results can be obtained, but the positioning result is unique. Therefore, the two positioning results need to be further screened. Specifically, the screening includes:

[0130] The movement trajectory of the user terminal can be determined through the acceleration information, moving direction, and attitude information of the user terminal; based on the movement trajectory and combined with 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. In step S1307, the server returns the positioning result to the user terminal or the display device through the wireless transmission network;

[0131] In this embodiment, wireless network support is required. The positioning information needs to be uploaded to the positioning server through the wireless network for positioning information processing, and then the positioning result is returned to the positioning result display device.

[0132] Step S1308, based on the positioning result determined in step S1306, within the next ΔT time, only the positioning is performed through the trajectory extrapolation method of the user terminal's own sensors.

[0133] Among them, ΔT is an integer multiple of the time window occupied by a single tag positioning at the base station. Since the trajectory extrapolation is obtained through time - speed integration operation, the size of ΔT will affect the positioning accuracy. The larger ΔT is, the larger the integration error is. We finally set the value of ΔT that meets the positioning accuracy of the user terminal through system debugging.

[0134] Within this ΔT time period, the user terminal positioning does not require the base station positioning signal. 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 this user terminal to other user terminals queuing for positioning.

[0135] Step S1309: After the trajectory extrapolation positioning in the ΔT time period ends, the user terminal resumes the TOF + trajectory extrapolation fusion positioning and reallocates the base station positioning resources to the user terminal.

[0136] The present invention mainly solves the problems of redundant positioning base stations, low system capacity, and battery life of user terminal tags in current mainstream positioning solutions. Since the tags in the TDOA system only send positioning messages in one-way and do not receive them, it is difficult to achieve cooperative positioning, and a large number of positioning base stations are required. Generally, four base stations are needed to complete positioning. Therefore, the present invention adopts the TOF positioning method, and alternately works through the trajectory extrapolation positioning that does not occupy base station resources and the TOF + trajectory extrapolation fusion positioning that occupies base station resources, which can not only ensure the positioning accuracy but also expand the system capacity.

[0137] The method and device in the above embodiments of the present invention can be applied to smart factories and smart cities. UWB communication devices are set at each physical entrance in a specific UWB two-dimensional positioning space. When a tag enters the system, the UWB communication device assigns the position coordinates of the current physical entrance to the tag as the initial tag position, and then connects the tag to the two-dimensional UWB positioning system in the embodiment of the present invention and runs the method in the embodiment of the present invention, then the position of the user terminal can be determined.

[0138] The above embodiments of the present invention can be used for positioning mobile user terminals such as mobile phones, smart watches, and intelligent robots. Currently, smart phones and watches both have GPS positioning functions, but the GPS positioning effect is not ideal indoors. When the user terminal enters the indoor environment, the user terminal will perform trajectory extrapolation through built-in gyroscopes, acceleration sensors, etc., and can estimate the approximate position. Combining with two ultra-wideband base stations in the two-dimensional UWB positioning system of the present invention, the user terminal can be accurately positioned, so that the initial position of the user terminal entering the two-dimensional UWB positioning system in the embodiment of the present invention can be determined. Subsequently, running the method in the embodiment of the present invention can determine the positions of mobile user terminals such as mobile phones, smart watches, and intelligent robots.

[0139] An embodiment of the present invention also provides a computer-readable storage medium, in which a computer program is stored. Wherein, the computer program is set to execute the steps in any one of the above method embodiments when running.

[0140] In an exemplary embodiment, the above computer-readable storage medium may include, but is not limited to: USB flash drives, read-only memories (ROM for short), random access memories (RAM for short), mobile hard disks, magnetic disks, or optical discs and other various media that can store computer programs.

[0141] An embodiment of the present invention further provides an electronic device, including a memory and a processor. A computer program is stored in the memory, and the processor is configured to run the computer program to execute the steps in any one of the above method embodiments.

[0142] In an exemplary embodiment, the above electronic device may further include a transmission device and an input / output device. The transmission device is connected to the processor, and the input / output device is connected to the processor.

[0143] Specific examples in this embodiment may refer to the examples described in the above embodiments and exemplary embodiments, and will not be repeated here.

[0144] Obviously, those skilled in the art should understand that the above modules or steps of the present invention can be implemented by a general-purpose computing device. They can be concentrated on a single computing device or distributed on a network composed of multiple computing devices. They can be implemented by program codes executable by the computing device. 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 executed in a different order from here, or they can be separately fabricated into individual integrated circuit modules, or multiple modules or steps among them can be fabricated into a single integrated circuit module to implement. In this way, the present invention is not limited to any specific combination of hardware and software.

[0145] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for ultra-wideband positioning, characterized in that, Applied to a positioning server, including: Determine the first positioning information of the user terminal after movement according to the initial position information before the movement of the user terminal, the first time-of-flight information reported by the ultra-wideband base station, and the first auxiliary positioning information reported during the movement of the user terminal; Determine the 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.

2. The method according to claim 1, characterized in that, Wherein, An ultra-wideband tag is set in the user terminal.

3. The method according to claim 1, characterized in that, 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, characterized in that, Determining the 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 through the second auxiliary positioning information to obtain a speed estimation result and a direction estimation result; Combine the speed estimation result, the direction estimation result, and the first positioning information to determine the second positioning information.

5. A method for ultra-wideband positioning, characterized in that, Applied to a user terminal, including: 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, where the first positioning information is determined based on the initial position information, the first auxiliary positioning information, and the first time-of-flight information reported by the ultra-wideband base station; Within a preset time interval after receiving the first positioning information, report the second auxiliary positioning information to the positioning server and receive the second positioning information returned by the positioning server, where 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, characterized in that, 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, characterized in that, Before reporting the initial position information before movement and the first auxiliary positioning information during 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; Compare the larger distance value between the first distance value and the second distance value with a preset distance threshold, and set the transceiver power level based on the comparison result; Based on the transceiver power level, interact with the first ultra-wideband base station and the second ultra-wideband for positioning signals.

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

9. The method according to claim 5, characterized in that, After receiving the first positioning information returned by the positioning server, the method further includes: Release the base station positioning window resources of the occupied ultra-wideband base station, where 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, characterized in that, The method further includes: Determine the frequency of positioning information interaction between the user terminal and the ultra-wideband base station 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 time of flight.

11. A positioning server, characterized in that, It includes: A first positioning module, configured to determine the first positioning information of the user terminal after movement according to the initial position information before the movement of the user terminal, the first time-of-flight information reported by the ultra-wideband base station, and the first auxiliary positioning information reported during the movement of the user terminal; A second positioning module, configured to determine the 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, characterized in that, It includes: A first reporting module, configured to report the initial position information before movement and the first auxiliary positioning information during movement to the positioning server; A first receiving module, configured to 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 time-of-flight information reported by the ultra-wideband base station; A second reporting module, configured to report the second auxiliary positioning information to the positioning server within a preset time interval after receiving the first positioning information; A second receiving module, configured to receive the 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, characterized in that, A computer program is stored in the computer-readable storage medium, wherein when the computer program is executed by a processor, the steps of the method described in any one of claims 1 to 4 are implemented, or the steps of the method described in any one of claims 5 to 10 are implemented.

14. An electronic device, comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that, When the processor executes the computer program, the steps of the method described in any one of claims 1 to 4 are implemented, or the steps of the method described in any one of claims 5 to 10 are implemented.

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