Fusion locating method, apparatus and system, and computer-readable storage medium

Abstract

Disclosed in the present application are a fusion locating method, apparatus and system, and a computer-readable storage medium. The method comprises: after a time difference of arrival (TDOA) broadcast locating message is broadcast to all base stations by means of a tag, a master base station recording a first receiving timestamp; sending a clock synchronization message to slave base stations, and recording a first sending timestamp; using the slave base stations to record a sequence of second receiving timestamps and a sequence of frequency offsets between the slave base stations and the master base station; on the basis of the sequence of second receiving timestamps, the sequence of frequency offsets, and the timestamp difference between the first sending timestamp and the first receiving timestamp, determining a sequence of tag-to-slave base station distances; and on the basis of a tag-to-master base station distance and the sequence of tag-to-slave base station distances, calculating the position of the tag, so as to locate the tag. The present application solves the technical problem in the relevant art of locating accuracy being relatively low due to the fact that fusion locating modes used for tag locating are prone to generating interference factors during locating.

Description

Fusion positioning method, device and system, and computer-readable storage medium

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on September 8, 2023, with application number: 202311164565.9, and application name: "Fusion positioning method, device and system, computer-readable storage medium", all contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of high-precision positioning, and specifically, to a fusion positioning method, device and system, and a computer-readable storage medium. Background Art

[0003] Currently, there are many methods for achieving positioning. For example, the TOF principle involves a tag using unilateral or bilateral ranging, communicating with three or more base stations through polling to obtain three or more distances. The tag's coordinates are then solved using a TOF spatial positioning algorithm. However, this method requires a high number of message transmissions, consumes a large amount of tags, and can accommodate a relatively small number of tags.

[0004] Fusion positioning can significantly reduce communication times and increase tag density and capacity, but many factors can affect positioning accuracy. For example, a fusion positioning method based on pseudolites and UWB, optimized on hardware, significantly improves indoor positioning accuracy, making positioning results more reliable and stable. However, this solution has poor feasibility, cannot maintain 1ps synchronization signal accuracy, and is susceptible to environmental interference. Another example is a fusion positioning method and system based on UWB and Bluetooth. Throughout the project implementation and deployment, this fusion positioning method leverages the advantages of Bluetooth and UWB positioning, achieving complementary advantages. However, the addition of Bluetooth can easily introduce interference from Bluetooth 2.4GHz radio frequency signals, and the presence of these interference factors can affect positioning accuracy.

[0005] Regarding the fusion positioning method used for positioning tags in the above-mentioned related technologies, interference factors are easily generated during positioning, resulting in low positioning accuracy. No effective solution has been proposed yet.

[0006] Summary of the Invention

[0007] The embodiments of the present application provide a fusion positioning method, device and system, and computer-readable storage medium to at least solve the technical problem that the fusion positioning method used in the related art to position tags is prone to interference factors during positioning, resulting in low positioning accuracy.

[0008] According to one aspect of an embodiment of the present application, a fusion positioning method is provided, including: after broadcasting an arrival time difference TDOA broadcast positioning message to a master base station and each slave base station through a tag, using the master base station to record a first reception timestamp of the received TDOA broadcast positioning message; after the master base station receives the TDOA broadcast positioning message, sending a clock synchronization message to each slave base station and recording the first transmission timestamp of the clock synchronization message; after each slave base station receives the clock synchronization message, using each slave base station to record a second reception timestamp sequence of the received clock synchronization message and a frequency offset sequence between each slave base station and the master base station; determining a tag-slave base station distance sequence between each slave base station and the tag based on the second reception timestamp sequence, the frequency offset sequence and the timestamp difference between the first transmission timestamp and the first reception timestamp; performing position solution on the tag based on the tag-master base station distance and the tag-slave base station distance sequence to obtain the tag's position information for positioning the tag.

[0009] Optionally, before broadcasting the arrival time difference TDOA broadcast positioning message to the main base station and each slave base station through the tag, it also includes: triggering the main base station and each slave base station to enter the broadcast receiving mode; triggering the tag to enter the message receiving mode after sending the TDOA broadcast positioning message.

[0010] Optionally, after broadcasting the arrival time difference TDOA broadcast positioning message to the main base station and each slave base station through the tag, it also includes: after each slave base station receives the TDOA broadcast positioning message, using each slave base station to record the third receiving timestamp sequence of the received TDOA broadcast positioning message and the signal strength sequence of the received TDOA broadcast positioning message; sorting the signal strength sequence and the first path signal strength sequence to obtain a sorting result; and selecting some base stations in each slave base station whose signal strength is greater than the signal strength threshold as target slave base stations according to the sorting result.

[0011] Optionally, the signal strength sequence and the first path signal strength sequence are sorted to obtain a sorting result, including: determining the integrated signal strength of each slave base station by a first formula under the signal strength sequence and the first path signal strength sequence to obtain an integrated signal strength sequence, wherein, in the first formula, k n =RSS n +10*(RSS n -ASS n -6), k n Indicates the nth slave station, RSS n Indicates the nth signal strength, ASS n represents the nth first path signal strength; sorting the integrated signal strengths in the integrated signal strength sequence to obtain a sorting result.

[0012] Optionally, selecting some of the slave base stations whose signal strengths are greater than a signal strength threshold as target slave base stations according to the sorting result includes: determining some base stations in the comprehensive signal strength sequence that exceed the signal strength threshold; and determining some base stations as target slave base stations.

[0013] Optionally, after the main base station receives the TDOA broadcast positioning message, it also includes: using the main base station to send a response message to the tag; after the tag receives the response message, using the tag to record the fourth receiving timestamp of the received response message and the RF signal frequency offset value error between the tag and the main base station, wherein the RF signal frequency offset value error is the error value obtained by monitoring the corresponding chip of the tag; determining the tag-main base station distance between the tag and the main base station based on the difference between the fourth receiving timestamp and the second sending timestamp of the TDOA broadcast positioning message sent by the tag, the difference between the first sending timestamp and the first receiving timestamp, and the RF signal frequency offset value error.

[0014] Optionally, determining the tag-main base station distance between the tag and the main base station according to the difference one between the fourth receiving timestamp and the second sending timestamp of the TDOA broadcast positioning message, the difference two between the first sending timestamp and the first receiving timestamp, and the radio frequency signal frequency offset value error, including: determining the distance time between the tag and the main base station according to the difference one, the difference two, and the radio frequency signal frequency offset value error through a second formula, wherein the second formula is: t d1 represents the distance time, t tag2 Indicates the fourth receiving timestamp, t tag1 Indicates the second sending timestamp, t s represents the first sending timestamp, t1 represents the first receiving timestamp, f tag Indicates the frequency offset error of the RF signal; the distance between the tag and the main base station is determined by the product of distance time and the speed of light.

[0015] Optionally, a tag-slave base station distance sequence between each slave base station and the tag is determined based on the second receiving timestamp sequence, the frequency offset sequence, and the timestamp difference between the first sending timestamp and the first receiving timestamp, including: determining an arrival time difference sequence between each slave base station and the master base station based on the second receiving timestamp sequence, the frequency offset sequence, and the timestamp difference between the first sending timestamp and the first receiving timestamp; determining a distance difference sequence between each slave base station and the master base station based on the product of each arrival time difference in the arrival time difference sequence and the speed of light; and determining a tag-slave base station distance sequence based on the distance difference sequence and the tag-master base station distance.

[0016] Optionally, after calculating the position of the tag according to the tag-main base station distance and the tag-slave base station distance sequence to obtain the tag's location information for locating the tag, it also includes: sending an end message to the main base station and each slave base station through the tag, wherein the end message includes the tag-main base station distance and the tag-slave base station distance sequence.

[0017] According to another aspect of an embodiment of the present application, a fusion positioning device is also provided, including: a first recording unit, for recording the first receiving timestamp of the received TDOA broadcast positioning message using the main base station after broadcasting the arrival time difference TDOA broadcast positioning message to the main base station and each slave base station through the tag; a second recording unit, for sending a clock synchronization message to each slave base station after the main base station receives the TDOA broadcast positioning message, and recording the first sending timestamp of the clock synchronization message; a third recording unit, for recording the second receiving timestamp sequence of the received clock synchronization message and the frequency offset sequence between each slave base station and the main base station after each slave base station receives the clock synchronization message; a determination unit, for determining the tag-slave base station distance sequence between each slave base station and the tag based on the second receiving timestamp sequence, the frequency offset sequence and the timestamp difference between the first sending timestamp and the first receiving timestamp; an acquisition unit, for performing position solution on the tag based on the tag-main base station distance and the tag-slave base station distance sequence to obtain the location information of the tag to locate the tag.

[0018] Optionally, the first recording unit further includes: a first trigger module, used to trigger the master base station and each slave base station to enter the broadcast receiving mode; and a second trigger module, used to trigger the tag to enter the message receiving mode after sending the TDOA broadcast positioning message.

[0019] Optionally, the first recording unit also includes: a first recording module, used to use each slave base station to record the third reception timestamp sequence of the received TDOA broadcast positioning message and the signal strength sequence of the received TDOA broadcast positioning message after each slave base station receives the TDOA broadcast positioning message; a sorting module, used to sort the signal strength sequence and the first path signal strength sequence to obtain a sorting result; a selection module, used to select some base stations in each slave base station whose signal strength is greater than the signal strength threshold as target slave base stations according to the sorting result.

[0020] Optionally, the sorting module includes: a first determining submodule, configured to determine the integrated signal strength of each slave base station using a first formula under the signal strength sequence and the first path signal strength sequence to obtain an integrated signal strength sequence, wherein the first formula, k n =RSS n +10*(RSS n -ASS n -6), k nIndicates the nth slave station, RSS n Indicates the nth signal strength, ASS n Indicates the nth first path signal strength; the sorting submodule is used to sort the comprehensive signal strengths in the comprehensive signal strength sequence to obtain a sorting result.

[0021] Optionally, the selection module includes: a second determination submodule, configured to determine some base stations in the integrated signal strength sequence that exceed a signal strength threshold; and a third determination submodule, configured to determine some base stations as target slave base stations.

[0022] Optionally, the second recording unit also includes: a response module, used to use the main base station to send a response message to the tag; a second recording module, used to use the tag to record the fourth receiving timestamp of the received response message and the RF signal frequency offset value error between the tag and the main base station after the tag receives the response message, wherein the RF signal frequency offset value error is the error value obtained by monitoring the corresponding chip of the tag; a first determination module, used to determine the tag-main base station distance between the tag and the main base station based on the difference between the fourth receiving timestamp and the second sending timestamp of the TDOA broadcast positioning message sent by the tag, the difference between the first sending timestamp and the first receiving timestamp, and the RF signal frequency offset value error.

[0023] Optionally, the first determination module includes: a fourth determination submodule, configured to determine the distance time between the tag and the primary base station according to the first difference, the second difference, and the RF signal frequency offset error using a second formula, wherein the second formula is: t d1 represents the distance time, t taa2 Indicates the fourth receiving timestamp, t tag1 Indicates the second sending timestamp, t s represents the first sending timestamp, t1 represents the first receiving timestamp, f taa Represents the frequency offset value error of the radio frequency signal; a fifth determination submodule, configured to determine the tag-main base station distance based on the product of distance time and the speed of light.

[0024] Optionally, the determination unit includes: a second determination module, used to determine the arrival time difference sequence of each slave base station and the master base station based on the second receiving timestamp sequence, the frequency offset sequence, and the timestamp difference between the first sending timestamp and the first receiving timestamp; a third determination module, used to determine the distance difference sequence between each slave base station and the master base station based on the product of each arrival time difference in the arrival time difference sequence and the speed of light; and a fourth determination module, used to determine the tag-slave base station distance sequence based on the distance difference sequence and the tag-master base station distance.

[0025] Optionally, the fusion positioning device further includes: a sending unit, configured to send an end message to the master base station and each slave base station via a tag, wherein the end message includes a tag-master base station distance and a tag-slave base station distance sequence.

[0026] According to another aspect of an embodiment of the present application, a fusion positioning system is further provided, which uses any of the fusion positioning methods described above.

[0027] According to another aspect of an embodiment of the present application, a computer-readable storage medium is further provided, wherein the computer-readable storage medium includes a stored program, wherein the program executes any one of the above-described fusion positioning methods.

[0028] According to another aspect of an embodiment of the present application, a processor is further provided, which is used to run a program, wherein the program executes any of the above-mentioned fusion positioning methods when running.

[0029] In an embodiment of the present application, after the arrival time difference TDOA broadcast positioning message is broadcast to the main base station and each slave base station through the tag, the main base station is used to record the first receiving timestamp of the received TDOA broadcast positioning message; after the main base station receives the TDOA broadcast positioning message, a clock synchronization message is sent to each slave base station, and the first sending timestamp of the clock synchronization message is recorded; after each slave base station receives the clock synchronization message, each slave base station is used to record the second receiving timestamp sequence of the received clock synchronization message and the frequency offset sequence between each slave base station and the main base station; the tag-slave base station distance sequence between each slave base station and the tag is determined according to the second receiving timestamp sequence, the frequency offset sequence and the timestamp difference between the first sending timestamp and the first receiving timestamp; the position of the tag is solved according to the tag-main base station distance and the tag-slave base station distance sequence to obtain the tag's position information to locate the tag. Through the above technical solution, the purpose of intelligently and adaptively screening out the base station with the best quality of receiving TDOA signals in the positioning framework to participate in tag positioning is achieved, so as to reduce the interference factors of NOLS interference and wireless clock synchronization accuracy, and achieve the effect of eliminating the influence of NLOS. At the same time, it also improves the technical effect of the accuracy of TOF+TDOA fusion positioning. Moreover, this method also streamlines the number of tag positioning communications and increases the tag capacity, thereby solving the technical problem that the fusion positioning method used for tag positioning in related technologies is prone to interference factors during positioning, resulting in low positioning accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0031] FIG1 is a hardware structure block diagram of a mobile terminal for a fusion positioning method according to an embodiment of the present application;

[0032] FIG2 is a flow chart of a fusion positioning method according to an embodiment of the present application;

[0033] FIG3 is a flow chart of an optional fusion positioning method according to an embodiment of the present application;

[0034] FIG4 is a schematic diagram of a tag broadcasting a positioning message according to an embodiment of the present application;

[0035] 5 is a schematic diagram of a primary base station responding to a ranging RESP message and a wireless clock synchronization message according to an embodiment of the present application;

[0036] FIG6 is a timing diagram of the fusion positioning method according to an embodiment of the present application;

[0037] FIG7 is a schematic diagram of the signal flight time of the distance between the master and slave base stations according to an embodiment of the present application;

[0038] FIG8 is a schematic diagram of a tag feedback distance according to an embodiment of the present application;

[0039] FIG9 is a schematic diagram of a device for fusion positioning according to an embodiment of the present application. DETAILED DESCRIPTION

[0040] In order to enable those skilled in the art to better understand the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of this application.

[0041] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequential order. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in a sequence other than those illustrated or described herein. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0042] As described in the background, the fusion positioning method used in related art to locate tags is prone to interference during positioning, resulting in low positioning accuracy. To address this shortcoming, the embodiments of this application provide a fusion positioning method, device, system, and computer-readable storage medium.

[0043] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application.

[0044] The method embodiments provided in the embodiments of the present application can be executed in a mobile terminal, a computer terminal 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 of a fusion positioning method in an embodiment of the present application. 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 MCU or a programmable logic device FPGA) 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.

[0045] 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 fusion positioning method in the embodiments of the present application. The processor 102 executes the computer programs stored in the memory 104 to perform 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 can be connected to the mobile terminal via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof. The transmission device 106 is used to receive or send data via a network. Specific examples of such networks may include wireless networks provided by the mobile terminal's telecommunications provider. In one example, 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 one example, the transmission device 106 may be a radio frequency (RF) module, which is used to communicate with the Internet wirelessly.

[0046] According to an embodiment of the present application, a method embodiment of a fusion positioning system is provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0047] FIG2 is a flow chart of a fusion positioning method according to an embodiment of the present application. As shown in FIG2 , the method includes the following steps:

[0048] Step S202: After broadcasting the time difference of arrival (TDOA) broadcast positioning message to the master base station and each slave base station through the tag, the master base station records the first receiving timestamp of receiving the TDOA broadcast positioning message.

[0049] Optionally, the master station and each slave base station are base stations used for tag positioning, and a master base station + slave base stations, tag positioning architecture is formed through the master base station, each slave base station, and the tag. The slave base stations are all base stations except the master base station in the master base station + slave base stations, tag positioning architecture.

[0050] The embodiment is described below in conjunction with Figure 3, which is a flowchart of an optional fusion positioning method of an embodiment of the present application. The tag will broadcast a TDOA message (i.e., a TDOA broadcast positioning message), and then the main base station will receive the TDOA broadcast message broadcast by the tag.

[0051] It should be noted that the fusion positioning architecture adopted in the embodiment of the present application can be: TOF+TDOA fusion positioning mode, which requires at least three base stations in the positioning cell, usually four base stations, and can be more base stations depending on the site conditions.

[0052] Since the positioning architecture of the master base station + slave base station and tag is adopted in the embodiment of the present application, the master base station serves as the synchronization base station and the TDOA signal reference base station, and no additional clock synchronization base station is required. The master base station sends a wireless clock synchronization message and sends the synchronization signal to the slave base station to realize wireless synchronization, which simplifies the structure of the entire positioning architecture and saves costs.

[0053] Optionally, the above-mentioned first receiving timestamp is the time when all base stations within the communication range can receive the TDOA broadcast positioning message sent by the tag after the main base station and all other slave base stations receive the TDOA broadcast positioning message sent by the tag. The main base station records the receiving timestamp as t1 (i.e., the first receiving timestamp).

[0054] According to the above embodiment of the present application, before the above step S202, that is, before broadcasting the arrival time difference TDOA broadcast positioning message to the main base station and each slave base station through the tag, it also includes: triggering the main base station and each slave base station to enter the broadcast receiving mode; triggering the tag to enter the message receiving mode after sending the TDOA broadcast positioning message.

[0055] Optionally, in the broadcast receiving mode, the tag will transmit a broadcast positioning TDOA message frame at a certain refresh time before sending the program, and all base stations are in receiving mode at this time.

[0056] Optionally, the relationship between the tag's TDOA broadcast positioning message transmission mode and the base station's broadcast receiving mode is as follows: after the tag enters the TDOA broadcast positioning message transmission mode and determines to transmit the TDOA broadcast positioning message, and after a delay of a certain period, the base station's broadcast receiving mode is enabled. In this mode, the tag begins the transmission process, and the master base station and each slave base station receive the TDOA broadcast positioning message sent by the tag.

[0057] This embodiment will be described below with reference to Figure 4, which is a schematic diagram of a tag broadcasting a positioning message according to an embodiment of the present application. As shown in Figure 4, the tag transmits a broadcast positioning TDOA message frame at a certain refresh time. At this time, all base stations are in receiving mode, and the transmission mode is to turn on reception after the delay time after transmission. The tag begins the transmission process, and all base stations (i.e., base station 1, base station 2, base station 3, and base station 4) record the reception time of the broadcast positioning TDOA message frame (i.e., t1, t2, t3, and t4).

[0058] For the tag, the purpose is to transmit the tag broadcast location and wait for the message response from the base station. The message content of the TDOA broadcast only contains the tag's unique ID, and the tag records the tag transmission timestamp as t tag1 (ie, the second sending timestamp).

[0059] For example, in a TOF+TDOA fusion positioning cell, there are four base stations, including one master base station and three slave base stations. The tag will first transmit a broadcast positioning TDOA message frame at a certain refresh time. At this time, all base stations are in broadcast receiving mode; the transmission mode is to delay the reception of each base station after transmitting the broadcast positioning TDOA message frame and enter the message receiving mode. The tag starts the sending program, and then the master base station and all other slave base stations will receive the TDOA broadcast positioning message sent by the tag.

[0060] According to the above-mentioned embodiment of the present application, after the above-mentioned step S202, that is, after broadcasting the arrival time difference TDOA broadcast positioning message to the main base station and each slave base station through the tag, it also includes: after each slave base station receives the TDOA broadcast positioning message, using each slave base station to record the third receiving timestamp sequence of the received TDOA broadcast positioning message and the signal strength sequence of the received TDOA broadcast positioning message; sorting the signal strength sequence and the first path signal strength sequence to obtain the sorting result; and selecting some base stations in each slave base station whose signal strength is greater than the signal strength threshold as the target slave base stations according to the sorting result.

[0061] Optionally, the third receiving timestamp sequence is that after the master base station and all other slave base stations receive the TDOA broadcast positioning message sent by the tag, all base stations within the communication range can receive the TDOA broadcast message sent by the tag, and the receiving timestamps recorded by each slave base station are t2, t3, t3...t n .

[0062] The above signal strength sequence and first path signal strength sequence are the signal strengths recorded by each slave base station after the tag sends the TDOA broadcast message.

[0063] The above-mentioned signal strength threshold means that after comprehensively considering the signal strength sequence and the first-path signal strength sequence and comprehensively ranking them, it is generally believed that the top three slave base stations are the base stations that receive the TDOA signal best, and they are listed as target slave base stations to participate in the next steps.

[0064] Optionally, in this embodiment, sorting the signal strength sequence and the first path signal strength sequence to obtain the sorting result may include: determining the integrated signal strength of each slave base station using a first formula under the signal strength sequence and the first path signal strength sequence to obtain the integrated signal strength sequence, wherein, in the first formula, k n =RSS n +10*(RSS n -ASS n -6), k n Indicates the nth slave station, RSS n Indicates the nth signal strength, ASS n represents the nth first path signal strength; sorting the integrated signal strengths in the integrated signal strength sequence to obtain a sorting result.

[0065] The above-mentioned comprehensive signal strength sequence is the comprehensive signal strength of each base station determined based on the signal strength sequence and the first path signal strength sequence, that is, the comprehensive signal evaluation quality, which can be used to evaluate the signal strength received by each base station. The received signal strength is recorded from the base station as RSS2, RSS2, RSS4...RSS n, respectively record the first path signal strength as ASS2, ASS2, ASS4...ASS n In order to minimize the impact of NLOS on TDOA messages, signal quality judgment and sorting are performed during reception. Sorting is performed based on received signal strength and first-path signal strength. The stronger the signal, the less interference it will receive. Therefore, the stronger the signal strength, the higher the ranking, and the weaker the signal, the lower the ranking. Received signal strength is used as the primary influencing factor, and received signal strength-first-path signal strength is used as the second influencing factor. In order to balance the influence of the two, the ranking can be performed according to the formula. The k calculated according to the first formula above represents the comprehensive signal evaluation quality. According to this value, the comprehensive signal strength of each slave base station is sorted to obtain the sorting result. The slave base station with the best TDOA signal quality can be selected to participate in the next step, thereby ensuring better positioning efficiency and higher accuracy.

[0066] Optionally, in this embodiment, selecting some base stations among the slave base stations whose signal strength is greater than the signal strength threshold as target slave base stations according to the sorting result includes: determining some base stations in the comprehensive signal strength sequence that exceed the signal strength threshold; and determining some base stations as target slave base stations.

[0067] For example, after the master and all other slave base stations receive a TDOA broadcast positioning message from a tag, the master and slave base stations record the corresponding timestamps, and each slave base station records the corresponding signal strength value and first-path signal strength value. Taking into account the influence of the two, the combined signal strength of each slave base station is ranked to obtain a ranking result. The three slave base stations with the best TDOA signal quality—that is, the top three slave base stations in the combined signal strength sequence—are selected as the slave base stations participating in the subsequent steps to complete precise positioning, ensuring more efficient and accurate positioning.

[0068] Step S204: After receiving the TDOA broadcast positioning message, the master base station sends a clock synchronization message to each slave base station and records the first sending timestamp of the clock synchronization message.

[0069] Optionally, the clock synchronization message is a wireless clock synchronization message transmitted by the master base station to the slave base station after the master base station receives the TDOA message.

[0070] Optionally, the first sending timestamp is that after the master base station receives the TDOA message, the master base station will immediately send a response ranging RESP message to the tag, and at the same time the master base station will also send a wireless clock synchronization message to the slave base station. Generally, these two messages are in the same message frame. After sending, the master base station records the sending timestamp t s (That is, the first sending timestamp).

[0071] The embodiment will be described below in conjunction with FIG5 , which is a schematic diagram of the master base station response ranging RESP message and wireless clock synchronization message in the embodiment of the present application. As shown in FIG5 , after the master base station receives the TDOA message, the master base station 1 will immediately transmit a ranging response RESP message to the tag, with the purpose of exchanging messages with the tag once, so as to achieve ranging between the tag and the base station; at the same time, the master base station 1 will also transmit a wireless clock synchronization message to the slave base stations (i.e., base station 2, base station 3, and base station 4), with the purpose of allowing the master and slave base stations to achieve time synchronization. This step requires the signal to reach the other party as quickly as possible to avoid excessive intermediate time waste resulting in increased time error. In order to transmit the signal as quickly as possible, the two messages are generally the same message frame, that is, the master base station only needs to respond to the message once in the air, thereby improving the efficiency of tag positioning.

[0072] As shown in Figure 3 above, after the master base station receives the tag's TDOA broadcast message, it will respond with a ranging RESP message and a wireless clock synchronization message. When the tag calculates the distance, the slave base station uses the frequency deviation to perform time synchronization clock correction.

[0073] The following describes this embodiment in conjunction with FIG6 , which is a timing diagram of the fusion positioning method of the embodiment of the present application. From the figure, it can be clearly seen that after the tag sends the TDOA broadcast message, the master and slave base stations receive the message, and then the master base station immediately sends a wireless clock synchronization message to the slave base station, that is, a clock message, and then the slave base station will feedback the message after receiving the message, that is, the frequency offset between the slave base station and the master base station. Among them, there will be a time difference between the master base station sending the synchronization message and the master and slave base stations receiving the message, that is, tt n -t n .

[0074] According to the above embodiment of the present application, in the above step S204, after the main base station receives the TDOA broadcast positioning message, it also includes: using the main base station to send a response message to the tag; after the tag receives the response message, using the tag to record the fourth receiving timestamp of the received response message and the RF signal frequency offset value error between the tag and the main base station, wherein the RF signal frequency offset value error is the error value obtained by monitoring the corresponding chip of the tag; according to the difference between the fourth receiving timestamp and the second sending timestamp of the TDOA broadcast positioning message sent by the tag, the difference between the first sending timestamp and the first receiving timestamp, and the RF signal frequency offset value error, the tag-main base station distance between the tag and the main base station is determined.

[0075] Optionally, the above response message is a ranging response RESP message sent by the primary base station to the tag after receiving the TDOA message.

[0076] Optionally, the fourth receiving timestamp is the receiving timestamp t recorded after the tag receives the response message transmitted by the primary base station.tag2 .

[0077] Optionally, in this embodiment, the tag-main base station distance between the tag and the main base station is determined according to the difference one between the fourth receiving timestamp and the second sending timestamp of the TDOA broadcast positioning message, the difference two between the first sending timestamp and the first receiving timestamp, and the radio frequency signal frequency offset value error, including: using a second formula, determining the distance time between the tag and the main base station according to the difference one, the difference two, and the radio frequency signal frequency offset value error, wherein the second formula is: t d1 represents the distance time, t tag2 Indicates the fourth receiving timestamp, t tag1 Indicates the second sending timestamp, t s represents the first sending timestamp, t1 represents the first receiving timestamp, f tag Indicates the frequency offset error of the RF signal; the distance between the tag and the main base station is determined by the product of distance time and the speed of light.

[0078] Optionally, the second sending timestamp is when the tag transmits TDOA broadcast information, and the tag records the tag sending timestamp as t tag1 .

[0079] For example, after the tag sends a TDOA broadcast message, the master and slave base stations will record the corresponding receiving timestamps and signal strengths. After receiving the TDOA broadcast message, the master base station will immediately send a response ranging RESP message to the tag and exchange messages with the tag to achieve ranging between the tag and the base station. After the tag receives the response RESP message from the master base station, it will immediately obtain the error in the RF signal offset value between the tag and the master base station. Due to the influence of the wireless clock synchronization accuracy, the clock synchronization needs to be corrected. The distance time between the tag and the base station after frequency offset correction can be obtained by formula calculation. The distance between the tag and the master base station can be determined according to the product of distance time and the speed of light. The tag distance calculated in this way is more accurate, and the positioning accuracy using this method will also be higher.

[0080] Step S206 : After each slave base station receives the clock synchronization message, each slave base station records a second reception timestamp sequence of the received clock synchronization message and a frequency offset sequence between each slave base station and the master base station.

[0081] Optionally, the second reception timestamp sequence is reception timestamps tt2, tt3, tt4, ... recorded after the slave base station receives the UWB wireless clock synchronization signal message from the master base station.

[0082] Step S208 : determining a tag-slave base station distance sequence between each slave base station and the tag according to the second receiving timestamp sequence, the frequency offset sequence, and the timestamp difference between the first sending timestamp and the first receiving timestamp.

[0083] Optionally, the frequency offset sequence is that after receiving the UWB wireless clock synchronization signal message from the master base station, the slave base station respectively records the frequency offset f from the master base station. err(2-1) , f err(3-1) , f err(4-1) …….

[0084] Optionally, a tag-slave base station distance sequence between each slave base station and the tag is determined based on the second receiving timestamp sequence, the frequency offset sequence, and the timestamp difference between the first sending timestamp and the first receiving timestamp, including: determining an arrival time difference sequence between each slave base station and the master base station based on the second receiving timestamp sequence, the frequency offset sequence, and the timestamp difference between the first sending timestamp and the first receiving timestamp; determining a distance difference sequence between each slave base station and the master base station based on the product of each arrival time difference in the arrival time difference sequence and the speed of light; and determining a tag-slave base station distance sequence based on the distance difference sequence and the tag-master base station distance.

[0085] Optionally, in this embodiment, since there is a certain distance between the master base station and the slave base station in actual arrangement, the distance between the master and slave base stations needs to be subtracted when calculating the wireless synchronization time, and the fixed distance between the master and slave base stations is expressed in terms of flight time, i.e., t d(2-1) , t d(3-1) , t d(4-1) .

[0086] The embodiment will be described below in conjunction with FIG7 , which is a schematic diagram of the signal flight time of the distance between the master and slave base stations in the embodiment of the present application. As shown in FIG7 , after the slave base station receives the UWB wireless clock synchronization signal message from the master base station, it records the reception timestamps tt2, tt3, tt4, etc., and at the same time, the slave base station respectively records the frequency offset f from the master base station. err(2-1) , f err(3-1) , f err(4-1) ......, it should be noted that since there is a certain distance between the master base station and the slave base station in actual layout, the distance between the master and slave base stations needs to be subtracted when calculating the wireless synchronization time. The fixed distance between the master and slave base stations is expressed in flight time, that is, t d(2-1) ,td (3-1) ,t d(4-1)As shown in Figure 7, the flight time from the master to the slave base station can be converted into distance using the set base station coordinates. The main purpose of recording the frequency offset error of the RF signal of the master and slave base stations is to correct the timestamp counting error caused by the crystal oscillator error and make the time error as small as possible. At this step, the relevant timestamp and offset parameters are determined, and the distance from the tag to the master and slave base stations can be calculated and the tag coordinates can be solved.

[0087] For example, according to the situation of the relevant timestamps on the time axis, from the time the tag transmits the TDOA message to the time the slave base station receives the UWB wireless synchronization message from the master base station, the pairwise arrival time difference of the tag's TDOA message at the master and slave base stations = the time period from the start time of the TDOA message to the time the slave base station receives the UWB wireless synchronization message from the master base station - the time period from the start time of the TDOA message to the time another slave base station receives the UWB wireless synchronization message from the master base station; that is, the TDOA arrival time difference can be calculated according to the third formula, where the third formula is: t eer(n-1) Represents the nth arrival time difference. According to this formula, the arrival time difference sequence can be obtained. Then, the distance difference sequence between each slave base station and the master base station is determined according to the product of each arrival time difference in the arrival time difference sequence and the speed of light. That is, the fourth formula is used for calculation, where the fourth formula is: err(n-1) =t err(n-1) *c(n=2,3,4),d err(n-1) is the distance difference, t err(n-1) is the arrival time difference, c is the speed of light; then the tag xy can be calculated by the TDOA algorithm, and the distance from the tag to the master base station is known, the distance from the tag to each slave base station can be calculated by the fifth formula, where the fifth formula is, d n =d err(n-1) +d1(n=2,3,4),d n is the distance from the tag to each slave base station, and d1 is the distance from the tag to the master base station. At this point, the distances from the tag to multiple base stations are all known, so the TOF positioning algorithm can be used to calculate the tag's position. This approach can achieve the same accuracy as TOF positioning while reducing the number of communications.

[0088] Step S210 , calculating the position of the tag according to the tag-primary base station distance and the tag-slave base station distance sequence to obtain the tag position information so as to locate the tag.

[0089] As can be seen from the above, in the embodiment of the present application, through the above steps, after the arrival time difference TDOA broadcast positioning message is broadcast to the master base station and each slave base station through the tag, the master base station is used to record the first receiving timestamp of the received TDOA broadcast positioning message; after the master base station receives the TDOA broadcast positioning message, a clock synchronization message is sent to each slave base station, and the first sending timestamp of the clock synchronization message is recorded; after each slave base station receives the clock synchronization message, each slave base station is used to record the second receiving timestamp sequence of the received clock synchronization message and the frequency offset sequence between each slave base station and the master base station; according to the second receiving timestamp sequence, the frequency offset sequence and the first sending timestamp and the frequency offset sequence, the first sending timestamp and the frequency offset sequence are recorded. The timestamp difference of the first received timestamp determines the tag-slave base station distance sequence between each slave base station and the tag; the tag position is solved according to the tag-master base station distance and the tag-slave base station distance sequence to obtain the tag position information to locate the tag, thereby achieving the purpose of intelligently and adaptively selecting the base station with the best quality of receiving TDOA signal in the positioning framework to participate in tag positioning, so as to reduce the interference factors of NOLS interference and wireless clock synchronization accuracy, and achieve the effect of eliminating the influence of NLOS, while also improving the technical effect of the accuracy of TOF+TDOA fusion positioning. Moreover, this method also reduces the number of tag positioning communications and increases the tag capacity.

[0090] Therefore, the technical solution provided by the embodiment of the present application solves the technical problem that the fusion positioning method used in the related art to position tags is prone to interference factors during positioning, resulting in low positioning accuracy.

[0091] Since the distance between the tag and the main base station can be calculated according to the formula in the tag, but the main base station cannot know the measured distance with the tag at this moment, the tag needs to send a final message to inform the base station of the distance, and then the communication logic of the TOF and TDOA fusion ends. Therefore, according to the above embodiment of the present application, after the above step S210, that is, after the position of the tag is calculated according to the tag-main base station distance and the tag-slave base station distance sequence to obtain the location information of the tag to locate the tag, it also includes: sending an end message to the main base station and each slave base station through the tag, wherein the end message includes the tag-main base station distance and the tag-slave base station distance sequence.

[0092] In this embodiment, after positioning, the tag can feed back its distance from the master base station (tag-master base station distance) to the master base station, and at the same time feed back its distance from each slave base station (tag-slave base station distance sequence) to each slave base station.

[0093] As shown in Figure 3, after the master base station responds to the ranging RESP message and the wireless clock synchronization message, the tag will calculate the distance and use the frequency deviation from the base station to perform time synchronization clock correction. After the tag calculates the distance to each base station, it will feedback the distance to each base station.

[0094] The following describes this embodiment in conjunction with FIG8 , which is a schematic diagram of the tag feedback distance in an embodiment of the present application. As shown in FIG8 , the tag sends an end message to the primary base station. This is because in the previous steps, the flow only flows into the tag, and the distance between the tag and the primary base station can be calculated according to the formula in the tag. However, at this moment, the primary base station cannot know the measured distance from the tag. Therefore, the tag needs to send a final message (that is, an end message) to inform the base station of the distance, thereby ending the communication logic of the TOF and TDOA fusion.

[0095] The crystal oscillator of the tag in the fusion positioning method proposed in this application is corrected with reference to the base station. Due to the frequency offset of the error of the clock crystal oscillator of each base station, even if the 38.4M crystal oscillator of the base station DW1000 adopts a TCXO active crystal oscillator and the frequency offset is controlled within 1ppm, a 1ps error may be generated within 1us, a 100ps error may be generated within 100us, a 1ns error may be generated within 1ms, and even a 1us error may be generated within 1s. Therefore, the main base station needs to complete clock synchronization within 1ms after receiving the broadcast positioning message of the tag to achieve a synchronization accuracy of 1ns=30cm. The shorter the time, the better. However, due to the SPI interface communication of the DW1000 chip, Due to the limitation of the data rate (20M / bit) and the transmission rate of UWB wireless signals (6.8M / bit), as well as the length of the UWB standard protocol, user data, and program execution time, a synchronization transition time of about 300us is required at the fastest. Therefore, the synchronization accuracy error is approximately within 300us*1ppm=300ps=10cm, and the positioning error accuracy can also be controlled within 20cm. Therefore, it is recommended that the base station use a TCXO active crystal oscillator to reduce the frequency offset of the UWB RF signal, increase measurement accuracy, improve anti-interference capability, and enhance receiving sensitivity.

[0096] It should be noted that for the aforementioned method embodiments, for the sake of simplicity, they are all expressed as a series of action combinations, but those skilled in the art should be aware that this application is not limited by the order of the actions described, because according to this application, certain steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily required by this application.

[0097] 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 application, 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), and includes 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 of each embodiment of the present application.

[0098] According to an embodiment of the present application, a fusion positioning device for implementing the above-mentioned fusion positioning method is also provided. FIG9 is a schematic diagram of the fusion positioning device according to an embodiment of the present application. As shown in FIG9 , the device includes: a first recording unit 91, a second recording unit 93, a third recording unit 95, a determination unit 97, and an acquisition unit 99. The fusion positioning system is described in detail below.

[0099] The first recording unit 91 is configured to record, using the master base station, a first receiving timestamp of a received TDOA broadcast positioning message after broadcasting the TDOA broadcast positioning message to the master base station and each slave base station through the tag.

[0100] The second recording unit 93 is configured to send a clock synchronization message to each slave base station after the master base station receives the TDOA broadcast positioning message, and record a first sending timestamp of the clock synchronization message.

[0101] The third recording unit 95 is configured to use each slave base station to record, after each slave base station receives the clock synchronization message, a second reception timestamp sequence of the received clock synchronization message and a frequency offset sequence between each slave base station and the master base station.

[0102] The determining unit 97 is configured to determine a tag-slave base station distance sequence between each slave base station and the tag according to the second receiving timestamp sequence, the frequency offset sequence, and the timestamp difference between the first sending timestamp and the first receiving timestamp.

[0103] The acquisition unit 99 is configured to calculate the position of the tag according to the tag-primary base station distance and the tag-slave base station distance sequence to obtain the tag position information so as to locate the tag.

[0104] It should be noted here that the above-mentioned first recording unit 91, second recording unit 93, third recording unit 95, determination unit 97 and acquisition unit 99 correspond to steps S202 to S210 in the above-mentioned embodiment. The five units have the same instances and application scenarios implemented by the corresponding steps, but are not limited to the contents disclosed in the above-mentioned embodiment.

[0105] From the above, it can be seen that in the scheme recorded in the above embodiments of the present application, the first recording unit can be used to broadcast the arrival time difference TDOA broadcast positioning message to the main base station and each slave base station through the tag, and the main base station can record the first receiving timestamp of the received TDOA broadcast positioning message; then the second recording unit can be used to send a clock synchronization message to each slave base station after the main base station receives the TDOA broadcast positioning message, and record the first sending timestamp of the clock synchronization message; then the third recording unit can be used to record the second receiving timestamp sequence of the received clock synchronization message and the frequency offset sequence between each slave base station and the main base station after each slave base station receives the clock synchronization message; the determination unit can then be used to determine the time difference according to the second receiving time. The tag-slave base station distance sequence between each slave base station and the tag is determined by the stamp sequence, frequency offset sequence, and the timestamp difference between the first sending timestamp and the first receiving timestamp; finally, the acquisition unit is used to solve the position of the tag according to the tag-master base station distance and the tag-slave base station distance sequence to obtain the location information of the tag, so as to achieve the purpose of intelligently and adaptively selecting the base station with the best quality of receiving TDOA signal in the positioning framework to participate in tag positioning, so as to reduce the interference factors of NOLS interference and wireless clock synchronization accuracy, and achieve the effect of eliminating the influence of NLOS, while also improving the technical effect of the accuracy of TOF+TDOA fusion positioning. Moreover, this method also reduces the number of communication times for tag positioning and increases the tag capacity.

[0106] Therefore, the technical solution provided by the embodiments of this application solves the technical problem that the fusion positioning method used in related technologies for tag positioning is prone to interference factors during positioning, resulting in low positioning accuracy. Optionally, before the first recording unit, it also includes: a first trigger module for triggering the master base station and each slave base station to enter broadcast reception mode; and a second trigger module for triggering the tag to enter message reception mode after sending a TDOA broadcast positioning message.

[0107] Optionally, after the first recording unit, it also includes: a first recording module, which is used to use each slave base station to record the third receiving timestamp sequence of the received TDOA broadcast positioning message and the signal strength sequence of the received TDOA broadcast positioning message after each slave base station receives the TDOA broadcast positioning message; a sorting module, which is used to sort the signal strength sequence and the first path signal strength sequence to obtain a sorting result; and a selection module, which is used to select some base stations in each slave base station whose signal strength is greater than the signal strength threshold as target slave base stations according to the sorting result.

[0108] Optionally, the sorting module includes: a first determining submodule, configured to determine the integrated signal strength of each slave base station using a first formula under the signal strength sequence and the first path signal strength sequence to obtain an integrated signal strength sequence, wherein the first formula, k n =RSS n +10*(RSS n -ASS n -6), k n Indicates the nth slave station, RSS n Indicates the nth signal strength, ASS n Indicates the nth first path signal strength; the sorting submodule is used to sort the comprehensive signal strengths in the comprehensive signal strength sequence to obtain a sorting result.

[0109] Optionally, the selection module includes: a second determination submodule, configured to determine some base stations in the integrated signal strength sequence that exceed a signal strength threshold; and a third determination submodule, configured to determine some base stations as target slave base stations.

[0110] Optionally, after the second recording unit, it also includes: a response module, used to use the main base station to send a response message to the tag; a second recording module, used to use the tag to record the fourth receiving timestamp of the received response message and the RF signal frequency offset value error between the tag and the main base station after the tag receives the response message, wherein the RF signal frequency offset value error is the error value obtained by monitoring the corresponding chip of the tag; a first determination module, used to determine the tag-main base station distance between the tag and the main base station based on the difference between the fourth receiving timestamp and the second sending timestamp of the TDOA broadcast positioning message sent by the tag, the difference between the first sending timestamp and the first receiving timestamp, and the RF signal frequency offset value error.

[0111] Optionally, the first determination module includes: a fourth determination submodule, configured to determine the distance time between the tag and the primary base station according to the first difference, the second difference, and the RF signal frequency offset error using a second formula, wherein the second formula is: t d1 represents the distance time, t tag2 Indicates the fourth receiving timestamp, t tag1 Indicates the second sending timestamp, t s represents the first sending timestamp, t1 represents the first receiving timestamp, f tag Represents the frequency offset error of the radio frequency signal; a fifth determining submodule, configured to determine the tag-main base station distance according to the product of the distance time and the speed of light.

[0112] Optionally, the determination unit includes: a second determination module, used to determine the arrival time difference sequence of each slave base station and the master base station based on the second receiving timestamp sequence, the frequency offset sequence, and the timestamp difference between the first sending timestamp and the first receiving timestamp; a third determination module, used to determine the distance difference sequence between each slave base station and the master base station based on the product of each arrival time difference in the arrival time difference sequence and the speed of light; and a fourth determination module, used to determine the tag-slave base station distance sequence based on the distance difference sequence and the tag-master base station distance.

[0113] Optionally, the fusion positioning device further includes: a sending unit, configured to send an end message to the master base station and each slave base station via a tag, wherein the end message includes a tag-master base station distance and a tag-slave base station distance sequence.

[0114] According to another aspect of an embodiment of the present application, a fusion positioning system is further provided, which uses any of the fusion positioning methods described above.

[0115] According to another aspect of an embodiment of the present application, a computer-readable storage medium is further provided, wherein the computer-readable storage medium includes a stored program, wherein the program executes any one of the above-mentioned fusion positioning methods.

[0116] Optionally, in this embodiment, the computer-readable storage medium may be located in any one of the computer terminals in a computer terminal group in a computer network, or in any one of the communication devices in a communication device group.

[0117] Optionally, in this embodiment, the computer-readable storage medium is configured to store program codes for executing the following steps: after broadcasting the arrival time difference TDOA broadcast positioning message to the main base station and each slave base station through the tag, using the main base station to record the first receiving timestamp of the received TDOA broadcast positioning message; after the main base station receives the TDOA broadcast positioning message, sending a clock synchronization message to each slave base station and recording the first sending timestamp of the clock synchronization message; after each slave base station receives the clock synchronization message, using each slave base station to record the second receiving timestamp sequence of the received clock synchronization message and the frequency offset sequence between each slave base station and the main base station; determining the tag-slave base station distance sequence between each slave base station and the tag based on the second receiving timestamp sequence, the frequency offset sequence and the timestamp difference between the first sending timestamp and the first receiving timestamp; solving the position of the tag based on the tag-main base station distance and the tag-slave base station distance sequence to obtain the location information of the tag to locate the tag.

[0118] Optionally, in this embodiment, the computer-readable storage medium is configured to store program codes for executing the following steps: triggering the master base station and each slave base station to enter a broadcast receiving mode; triggering the tag to enter a message receiving mode after sending a TDOA broadcast positioning message.

[0119] Optionally, in this embodiment, the computer-readable storage medium is configured to store program code for executing the following steps: after each slave base station receives the TDOA broadcast positioning message, use each slave base station to record the third reception timestamp sequence of the received TDOA broadcast positioning message and the signal strength sequence of the received TDOA broadcast positioning message; sort the signal strength sequence and the first path signal strength sequence to obtain a sorting result; and select some base stations in each slave base station whose signal strength is greater than the signal strength threshold as target slave base stations based on the sorting result.

[0120] Optionally, in this embodiment, the computer-readable storage medium is configured to store program code for executing the following steps: determining the integrated signal strength of each slave base station using a first formula under the signal strength sequence and the first path signal strength sequence to obtain an integrated signal strength sequence, wherein, in the first formula, k n =RSS n +10*(RSS n -ASS n -6), k n Indicates the nth slave station, RSS n Indicates the nth signal strength, ASS n represents the nth first path signal strength; sorting the integrated signal strengths in the integrated signal strength sequence to obtain a sorting result.

[0121] Optionally, in this embodiment, the computer-readable storage medium is configured to store program codes for executing the following steps: determining some base stations in the integrated signal strength sequence that exceed a signal strength threshold; and determining some base stations as target slave base stations.

[0122] Optionally, in this embodiment, the computer-readable storage medium is configured to store program code for executing the following steps: using the main base station to send a response message to the tag; after the tag receives the response message, using the tag to record the fourth receiving timestamp of the received response message and the RF signal frequency offset value error between the tag and the main base station, wherein the RF signal frequency offset value error is the error value obtained by monitoring the corresponding chip of the tag; determining the tag-main base station distance between the tag and the main base station based on the difference between the fourth receiving timestamp and the second sending timestamp of the TDOA broadcast positioning message sent by the tag, the difference between the first sending timestamp and the first receiving timestamp, and the RF signal frequency offset value error.

[0123] Optionally, in this embodiment, the computer-readable storage medium is configured to store program code for executing the following steps: determining the distance time between the tag and the primary base station according to the first difference, the second difference, and the radio frequency signal frequency offset error using a second formula, wherein the second formula is: t d1 represents the distance time, t tag2 Indicates the fourth receiving timestamp, t t2g1 Indicates the second sending timestamp, t s represents the first sending timestamp, t1 represents the first receiving timestamp, f t2g Indicates the frequency offset error of the RF signal; the distance between the tag and the main base station is determined by the product of distance time and the speed of light.

[0124] Optionally, in this embodiment, the computer-readable storage medium is configured to store program code for performing the following steps: determining an arrival time difference sequence between each slave base station and the master base station based on the second receiving timestamp sequence, the frequency offset sequence, and the timestamp difference between the first sending timestamp and the first receiving timestamp; determining a distance difference sequence between each slave base station and the master base station based on the product of each arrival time difference in the arrival time difference sequence and the speed of light; determining a tag-slave base station distance sequence based on the distance difference sequence and the tag-master base station distance.

[0125] Optionally, in this embodiment, the computer-readable storage medium is configured to store program code for performing the following steps: sending an end message to the master base station and each slave base station via a tag, wherein the end message includes a tag-master base station distance and a tag-slave base station distance sequence.

[0126] According to another aspect of an embodiment of the present application, a processor is further provided, which is used to run a program, wherein the program executes any one of the above-mentioned fusion positioning methods when running.

[0127] The serial numbers of the above embodiments of the present application are for description only and do not represent the advantages or disadvantages of the embodiments.

[0128] In the above embodiments of the present application, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, please refer to the relevant description of other embodiments.

[0129] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. Among them, the device embodiments described above are only exemplary. For example, the division of units can be a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of units or modules, which can be electrical or other forms.

[0130] Units described as separate components may or may not be physically separate, and components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple units. Some or all of the units may be selected to achieve the purpose of the present embodiment according to actual needs.

[0131] In addition, the functional units in the various embodiments of the present application may be integrated into a single processing unit, or each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0132] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for enabling a computer device (which can be a personal computer, server or network device, etc.) to execute all or part of the steps of the various embodiments of the present application. The aforementioned storage medium includes: U disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), mobile hard disk, magnetic disk or optical disk and other media that can store program code.

[0133] The above is only a preferred embodiment of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A fusion positioning method, comprising: After broadcasting the arrival time difference TDOA broadcast positioning message to the master base station and each slave base station through the tag, using the master base station to record the first receiving timestamp of receiving the TDOA broadcast positioning message; After the master base station receives the TDOA broadcast positioning message, it sends a clock synchronization message to each of the slave base stations and records a first sending timestamp of the clock synchronization message; After each of the slave base stations receives the clock synchronization message, using each of the slave base stations to record a second reception timestamp sequence of the clock synchronization message received and a frequency offset sequence between each of the slave base stations and the master base station; Determine a tag-slave base station distance sequence between each of the slave base stations and the tag according to the second receiving timestamp sequence, the frequency offset sequence, and a timestamp difference between the first sending timestamp and the first receiving timestamp; The position of the tag is calculated according to the tag-primary base station distance and the tag-slave base station distance sequence to obtain the position information of the tag so as to locate the tag.

2. The fusion positioning method according to claim 1, wherein: Before broadcasting the time difference of arrival TDOA broadcast positioning message to the master base station and each slave base station through the tag, it also includes: Triggering the master base station and each of the slave base stations to enter a broadcast receiving mode; The tag is triggered to enter a message receiving mode after sending the TDOA broadcast positioning message.

3. The fusion positioning method according to claim 1, wherein: After broadcasting the time difference of arrival TDOA broadcast positioning message to the master base station and each slave base station through the tag, it also includes: After each of the slave base stations receives the TDOA broadcast positioning message, using each of the slave base stations to record a third reception timestamp sequence of the received TDOA broadcast positioning message and a signal strength sequence of the received TDOA broadcast positioning message; Sorting the signal strength sequence and the first path signal strength sequence to obtain a sorting result; According to the ranking result, some of the slave base stations whose signal strength is greater than a signal strength threshold are selected as target slave base stations.

4. The fusion positioning method according to claim 3, wherein: The signal strength sequence and the first path signal strength sequence are sorted to obtain a sorting result, including: Under the signal strength sequence and the first path signal strength sequence, the comprehensive signal strength of each of the slave base stations is determined by a first formula to obtain a comprehensive signal strength sequence, wherein, in the first formula, k n =RSS n +10*(RSS n -ASS n -6), k n Indicates the nth slave base station, RSS n Indicates the nth signal strength, ASS n Indicates the signal strength of the nth first path; The integrated signal strengths in the integrated signal strength sequence are sorted to obtain a sorting result.

5. The fusion positioning method according to claim 4, wherein: Selecting, according to the ranking result, some of the slave base stations whose signal strengths are greater than a signal strength threshold as target slave base stations, including: Determine the portion of base stations in the integrated signal strength sequence that exceed the signal strength threshold; The part of base stations is determined as the target slave base stations.

6. The fusion positioning method according to claim 1, wherein: After the primary base station receives the TDOA broadcast positioning message, the method further includes: Using the primary base station to send a response message to the tag; After the tag receives the response message, the tag is used to record a fourth receiving timestamp of receiving the response message and a frequency offset value error of a radio frequency signal between the tag and the primary base station, wherein the frequency offset value error of the radio frequency signal is an error value obtained by monitoring a chip corresponding to the tag; The tag-main base station distance between the tag and the main base station is determined based on the difference one between the fourth receiving timestamp and the second sending timestamp of the tag sending the TDOA broadcast positioning message, the difference two between the first sending timestamp and the first receiving timestamp, and the RF signal frequency offset value error.

7. The fusion positioning method according to claim 6, wherein: Determining the tag-main base station distance between the tag and the main base station according to a difference value 1 between the fourth receiving timestamp and the second sending timestamp of the TDOA broadcast positioning message, a difference value 2 between the first receiving timestamp and the sending timestamp, and the radio frequency signal frequency offset value error, including: The distance time between the tag and the primary base station is determined according to the difference 1, the difference 2 and the frequency offset value error of the radio frequency signal by a second formula, wherein the second formula is: t d1 represents the distance time, t tag2 represents the fourth receiving timestamp, t tag1 represents the second sending timestamp, t s represents the first sending timestamp, and t1 represents the first receiving timestamp Timestamp, f tag Indicates the frequency offset value error of the radio frequency signal; The tag-primary base station distance is determined according to the product of the distance time and the speed of light.

8. The fusion positioning method according to claim 1, wherein: Determining a tag-slave base station distance sequence between each of the slave base stations and the tag according to the second receiving timestamp sequence, the frequency offset sequence, and a timestamp difference between the first sending timestamp and the first receiving timestamp, comprising: Determine an arrival time difference sequence between each of the slave base stations and the master base station according to the second receiving timestamp sequence, the frequency offset sequence, and a timestamp difference between the first sending timestamp and the first receiving timestamp; Determine a distance difference sequence between each of the slave base stations and the master base station according to the product of each arrival time difference in the arrival time difference sequence and the speed of light; The tag-slave base station distance sequence is determined according to the distance difference sequence and the tag-master base station distance.

9. The fusion positioning method according to any one of claims 1 to 8, wherein: After calculating the position of the tag according to the tag-primary base station distance and the tag-slave base station distance sequence to obtain the position information of the tag to locate the tag, the method further includes: An end message is sent to the primary base station and each of the secondary base stations through the tag, wherein the end message includes a sequence of the tag-primary base station distance and the tag-secondary base station distance.

10. A fusion positioning device, comprising: A first recording unit is configured to, after broadcasting a time difference of arrival TDOA broadcast positioning message to a master base station and each slave base station through a tag, record a first receiving timestamp of receiving the TDOA broadcast positioning message by using the master base station; A second recording unit is configured to send a clock synchronization message to each of the slave base stations after the master base station receives the TDOA broadcast positioning message, and record a first sending timestamp of the clock synchronization message; A third recording unit is configured to, after each of the slave base stations receives the clock synchronization message, use each of the slave base stations to record a second reception timestamp sequence of the clock synchronization message received and a frequency offset sequence between each of the slave base stations and the master base station; a determining unit configured to determine a tag-slave base station distance sequence between each of the slave base stations and the tag according to the second receiving timestamp sequence, the frequency offset sequence, and a timestamp difference between the first sending timestamp and the first receiving timestamp; The acquisition unit is configured to perform position calculation on the tag according to the tag-primary base station distance and the tag-slave base station distance sequence to obtain the position information of the tag so as to locate the tag.

11. A fusion positioning system, wherein the fusion positioning system uses the fusion positioning method according to any one of claims 1 to 9.

12. A computer-readable storage medium, the computer-readable storage medium comprising a stored program, wherein: The program executes the fusion positioning method described in any one of claims 1 to 9.

13. A processor for running a program, wherein: When the program is run, the fusion positioning method described in any one of claims 1 to 9 is executed.

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