Position fingerprint positioning method and positioning system

Abstract

The present application provides a location fingerprint positioning method and a positioning system, the positioning method comprising: deploying a positioning base station outside a building, and marking its location information in a BIM map; performing offline location collection by a positioning terminal, and building a location fingerprint library; estimating the location of the positioning terminal according to the distance between the positioning terminal and the positioning base station; calculating the distance ratio of each location collection point of the positioning terminal in space, such as up, down, left, right, front, and back; performing real-time location collection and optimization by the positioning terminal, and obtaining final real-time location information; calculating the Euclidean distance between the final real-time location information and the optimized data of each location collection point in the location fingerprint library; and performing weighting, and taking the minimum value in the final result as the final location information of the positioning terminal; displaying the final location information of the positioning terminal in a BIM map, and obtaining a location mapping corresponding to the real world, so as to complete the positioning of the positioning terminal in a low-cost and lightweight manner.

Description

Technical Field

[0001] The present application belongs to the field of indoor positioning, and specifically relates to a location fingerprint positioning method and a positioning system. Background Art

[0002] In the era of the Internet of Things, indoor location information is becoming increasingly important. In recent years, with the advancement and popularization of various positioning technologies such as WiFi, Bluetooth, UWB, Zigbee positioning, and 5G positioning, indoor positioning systems have received widespread attention and application in more and more scenarios. WiFi positioning has limited positioning accuracy, and the network stability and reliability are not strong, so it is suitable for general positioning needs. Bluetooth AoA positioning has obvious advantages in power consumption and price, but its coverage is small, it cannot penetrate walls, and it is complex and costly to deploy. UWB positioning technology has advantages in accuracy that other positioning technologies cannot match, but its power consumption is relatively high, and it also has the problem of not being able to penetrate walls and the ground, and the cost of deployment and installation is very high.

[0003] When the above positioning methods are deployed and implemented, there are problems such as major deployment changes to the internal facilities of the building, the positioning base station requires wired connection, and the installation and commissioning workload is large. Summary of the invention

[0004] In order to overcome the problems existing in the related art at least to a certain extent, the present application provides a position fingerprint positioning method and a positioning system.

[0005] According to a first aspect of an embodiment of the present application, the present application provides a location fingerprint positioning method, which comprises the following steps:

[0006] Deploy the positioning base station outside the building and mark the location information of the positioning base station on the BIM map;

[0007] The positioning terminal collects offline positions and uses the collected offline position information to build a position fingerprint library;

[0008] Estimate the location of the positioning terminal according to the distance between the positioning terminal and the positioning base station;

[0009] According to the location of the positioning terminal, calculate the distance ratio of the collection points at the upper, lower, left, right, front and back positions of the positioning terminal in space, and use the distance ratio as the subsequent weighted value;

[0010] The positioning terminal collects real-time position information and optimizes the collected real-time position information using the Gaussian distribution function to obtain the final real-time position information;

[0011] Calculate the Euclidean distance between the final real-time location information and the optimized data of each location collection point in the location fingerprint library; and weight the Euclidean distances corresponding to each location collection point above, below, left, right, front, and back of the location of the positioning terminal, and use the minimum value of the final result as the final location information of the positioning terminal;

[0012] The final location information of the positioning terminal is displayed in the BIM map to obtain a one-to-one corresponding location mapping with the real world to complete the positioning of the positioning terminal.

[0013] The above-mentioned location fingerprint positioning method further includes the following steps:

[0014] After each positioning base station is turned on, a synchronous communication network is formed, and the positioning terminal is connected to the synchronous communication network;

[0015] The location background management system displays the final location information of the positioning terminal in real time on the user interface with BIM as the reference map, so as to record and track the movement trajectory of the positioning terminal, and use the synchronous communication network to send or receive short messages to the positioning terminal.

[0016] In the above-mentioned location fingerprint positioning method, the positioning terminal performs offline location collection, and the specific process of using the collected offline location information to build a location fingerprint library is as follows:

[0017] Set the location collection point LA according to the preset distance interval i , where i represents the number of location collection points, i = 1, 2, ..., n;

[0018] Place the positioning terminal at the location collection point LA i , record the positioning base station t received by the positioning terminal j The strength of the transmitted signal RSSI j1 ,RSSI j2 ,......,RSSI jr and bit error rate ERR j1 ,ERR j2 ,......,ERR jr , where j represents the number of positioning base stations, j = 1, 2, ..., k;

[0019] Using Gaussian distribution function to locate base station t j The strength of the transmitted signal RSSI j1 ,RSSI j2 ,......,RSSI jr and bit error rate ERR j1 ,ERR j2 ,......,ERR jrAfter optimization, the signal strength and bit error rate are (RSSIt j ,ERRt j ), then the location collection point LA i The location information is marked as LA i (RSSIit1, ERRit1; RSSIit2, ERRit2; ...; RSSIit j , ERRt j ; ... ; RSSIit k , ERRit k ), where (RSSIit j , ERRit j ) represents the jth positioning base station t received by the i-th location collection point j The value after optimizing the strength of the transmitted signal and the received bit error rate;

[0020] The optimized data of each location collection point is placed in a data table to obtain a location fingerprint library; wherein the location fingerprint library is in the form of:

[0021]

[0022] In the location fingerprint positioning method, the specific process of estimating the location of the positioning terminal according to the distance between the positioning terminal and the positioning base station is:

[0023] The TOA ranging method is used to estimate the distance between the positioning terminal and at least three positioning base stations, where the distance estimation formula is:

[0024]

[0025] Where A represents the absolute value of RSSI when the positioning terminal is 1 meter away from the positioning base station, α represents the environmental attenuation factor, and d represents the estimated distance;

[0026] Using the spatial three-point positioning algorithm, the location L1 of the positioning terminal is estimated according to the distance between the positioning terminal and each base station. The specific process is as follows:

[0027] Assume that the location coordinates of the positioning terminal are (x, y, z);

[0028] It is known that the position coordinates of the first positioning base station are (x1, y1, z1), the position coordinates of the second positioning base station are (x2, y2, z2), and the position coordinates of the third positioning base station are (x3, y3, z3);

[0029] According to the distance estimation formula, the distances between the positioning terminal and the first positioning base station, the second positioning base station and the third positioning base station are d1, d2, and d3 respectively. Then, the relationship equations between the distances between the positioning terminal and the positioning base station and the position coordinates of the positioning terminal and the position coordinates of the positioning base station are as follows:

[0030]

[0031] The position coordinates of the positioning terminal are calculated based on the relationship equation group.

[0032] Furthermore, the specific process of calculating the distance ratio of the collection points at the upper, lower, left, right, front and rear positions of the positioning terminal in space according to the position of the positioning terminal is as follows:

[0033] Set the distance D between adjacent location collection points, and the distance between location L1 and each location collection point is dc1, dc2, dc3, dc4, dc5, dc6, then the distance ratios R1, R2, R3, R4, R5, R6 are:

[0034]

[0035] Furthermore, the time synchronization between the positioning base stations includes external synchronization and internal synchronization;

[0036] The external synchronization is to achieve time synchronization between various positioning base stations by relying on the second pulse of Beidou or GPS positioning module;

[0037] The internal synchronization relies on a self-elected master node to send a broadcast frame, and other positioning base stations detect the broadcast frame through synchronization and maintain time synchronization with the master node.

[0038] Furthermore, the process of self-nominating the master node for networking is:

[0039] After the positioning base stations are randomly powered on, the first one to be powered on will search for broadcast frames sent by other positioning base stations within a fixed time. If it cannot be found, it will automatically switch its status to the master node and send broadcast frames. After searching for the broadcast frames of the master node, other positioning base stations will synchronize with the master node.

[0040] Furthermore, the specific process of the positioning terminal accessing the synchronous communication network is:

[0041] After the positioning terminal searches for the broadcast frame sent by the positioning base station, it performs time synchronization and sends an access frame;

[0042] After receiving the access request from the positioning terminal, the positioning base station allocates an idle time slot;

[0043] The positioning terminal communicates with the positioning base station in the idle time slot.

[0044] According to a second aspect of the embodiment of the present application, the present application also provides a location fingerprint positioning system, which includes a positioning base station, a positioning terminal, a processor, a BIM library and a location background management subsystem;

[0045] The positioning base station is deployed outside the building, and a synchronous communication network is formed between the positioning terminal and the positioning base station;

[0046] The positioning terminal is used to collect offline position and real-time position, and send the collected information to the processor;

[0047] The processor is used to build a location fingerprint library according to the offline location information, estimate the location of the positioning terminal according to the distance between the positioning terminal and the positioning base station and calculate the weighted value, and is also used to calculate the final real-time location information of the positioning terminal according to the real-time location information, and is also used to match the final real-time location information with the location fingerprint library to output the final location information of the positioning terminal;

[0048] The BIM library is used to annotate and display the location information of the positioning base station and the positioning terminal.

[0049] The above-mentioned location fingerprint positioning system also includes a location background management subsystem, which is used to record and track the movement trajectory of the positioning terminal and use the synchronous communication network to complete the sending or receiving of short messages to the positioning terminal.

[0050] According to the above specific implementation methods of the present application, it can be known that at least the following beneficial effects are achieved: the location fingerprint positioning method provided by the present application estimates the position of the positioning terminal in space and the weighted value calculated according to the position through the offline location information and real-time location information collected by the positioning terminal and the TOA ranging method, and then obtains the final location information of the positioning terminal and displays it in the BIM map, thereby completing the positioning of the positioning terminal; in the present application, wireless interconnection is achieved between the positioning base station and the positioning terminal, which not only avoids the wired connection of the traditional positioning base station, does not require major deployment changes to the internal facilities of the building, but also enables simultaneous transmission of positioning and short messages; combining the positioning information with the BIM map can achieve complete indoor positioning

[0051] This application uses a high-sensitivity, low-power LPWAN positioning base station to realize wireless signal fingerprint collection and communication, which can reduce the number of positioning base stations deployed; the combination of TOA ranging and fingerprint matching can improve positioning accuracy.

[0052] It should be understood that the above general description and the following specific embodiments are only exemplary and illustrative and do not limit the scope of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] The attached drawings below are part of the specification of the present application, which illustrate embodiments of the present application. The attached drawings together with the description of the specification are used to explain the principles of the present application.

[0054] Figure 1 A flowchart of a location fingerprint positioning method provided for a specific implementation of the present application.

[0055] Figure 2 A schematic diagram of the relative position relationship between each positioning base station and the positioning terminal in a position fingerprint positioning method provided in a specific implementation manner of the present application.

[0056] Figure 3 A schematic diagram of the application of a location fingerprint positioning method in a building provided in a specific implementation manner of the present application. DETAILED DESCRIPTION

[0057] In order to make the purpose, technical solutions and advantages of the embodiments of the present application more clearly understood, the spirit of the contents disclosed in the present application will be clearly explained with the accompanying drawings and detailed descriptions below. After understanding the embodiments of the contents of the present application, any technician in the relevant technical field can change and modify them according to the techniques taught by the contents of the present application without departing from the spirit and scope of the contents of the present application.

[0058] The exemplary embodiments and descriptions of the present application are used to explain the present application, but are not intended to limit the present application. In addition, elements / components with the same or similar reference numerals used in the drawings and embodiments are used to represent the same or similar parts.

[0059] The terms “first”, “second”, etc. used in this document do not particularly refer to an order or sequence, nor are they used to limit this application. They are only used to distinguish elements or operations described with the same technical terms.

[0060] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0061] As used herein, "and / or" includes any or all combinations of the items described.

[0062] As used herein, “plurality” includes “two” and “more than two”; as used herein, “plurality of groups” includes “two groups” and “more than two groups”.

[0063] Certain terms used to describe the present application are discussed below or elsewhere in this specification to provide additional guidance to those skilled in the art regarding the description of the present application.

[0064] like Figure 1As shown, the embodiment of the present application provides a location fingerprint positioning method, which is used to locate the interior of a building, and includes the following steps:

[0065] S1. Deploy k positioning base stations outside the building, and mark the location information of the positioning base stations in the BIM (Building Information Modeling) map.

[0066] S2. The positioning terminal collects offline positions and uses the collected offline position information to build a position fingerprint library. The specific process is as follows:

[0067] S21. Set the location collection point LA according to the preset distance interval i , where i represents the number of location collection points, i=1,2,......,n.

[0068] S22. Place the positioning terminal at the location collection point LA i , record the positioning base station t received by the positioning terminal j The strength of the transmitted signal RSSI j1 ,RSSI j2 ,......,RSSI jr and bit error rate ERR j1 ,ERR j2 ,......,ERR jr , where j represents the number of positioning base stations, j=1,2,......,k.

[0069] S23, using Gaussian distribution function to locate base station t j The strength of the transmitted signal RSSI j1 ,RSSI j2 ,......,RSSI jr and bit error rate ERR j1 ,ERR j2 ,......,ERR jr After optimization, the signal strength and bit error rate are (RSSIt j ,ERRt j ), then the location collection point LA i The location information is marked as LA i (RSSIit1, ERRit1; RSSIit2, ERRit2; ...; RSSIit j , ERRt j ; ... ; RSSIit k , ERRit k ), where (RSSIit j , ERRit j) represents the jth positioning base station t received by the i-th location collection point j The value after optimizing the strength of the transmitted signal and the received bit error rate.

[0070] S24, placing the optimized data of each location collection point in a data table to obtain the following location fingerprint library LW:

[0071]

[0072] S3, estimating the location of the positioning terminal according to the distance between the positioning terminal and the positioning base station, the specific process is as follows:

[0073] The TOA ranging method is used to estimate the distance between the positioning terminal and m (m ≥ 3) positioning base stations, where the distance estimation formula is:

[0074]

[0075] In formula (1), A represents the absolute value of RSSI when the positioning terminal is 1 meter away from the positioning base station, α represents the environmental attenuation factor, and d represents the estimated distance.

[0076] like Figure 2 As shown, using the spatial three-point positioning algorithm, the location L1 of the positioning terminal can be estimated according to the distance between the positioning terminal and each base station. The specific process is as follows:

[0077] Assume that the location coordinates of the positioning terminal are (x, y, z); the location coordinates of the first positioning base station are known to be (x1, y1, z1), the location coordinates of the second positioning base station are known to be (x2, y2, z2), and the location coordinates of the third positioning base station are known to be (x3, y3, z3); ​​according to formula (1), the distances between the positioning terminal and the first positioning base station, the second positioning base station, and the third positioning base station are known to be d1, d2, and d3, respectively. Then, the relationship between the distance between the positioning terminal and the positioning base station and the location coordinates of the positioning terminal and the location coordinates of the positioning base station is:

[0078]

[0079] According to formula (2), the location coordinates of the positioning terminal can be obtained.

[0080] S4. According to the location L1 of the positioning terminal, calculate the distance ratios [R1, R2, R3, R4, R5, R6] of the six location collection points above, below, left, right, front and back of the location L1 in space, and use the distance ratios as subsequent weighted values.

[0081] Among them, the distance between adjacent collection points in the 6 locations is D, and the distance between location L1 and the 6 collection points is dc1, dc2, dc3, dc4, dc5, dc6. The distance ratios R1, R2, R3, R4, R5, and R6 are:

[0082]

[0083] S5. The positioning terminal collects real-time position information and optimizes the collected real-time position information using a Gaussian distribution function to obtain final real-time position information.

[0084] Among them, the final real-time location information is:

[0085] LR(RSSIt1,ERRt1;RSSIt2,ERRt2;...;RSSIt k ,ERRt k ).

[0086] S6. Match the final real-time location information with the location fingerprint library, that is, calculate the Euclidean distance between the final real-time location information and the optimized data of each location collection point in the location fingerprint library; and weight the Euclidean distances corresponding to the six location collection points above, below, left, right, front, and back of the location of the positioning terminal, that is, multiply the Euclidean distances corresponding to the six location collection points by each weighted value, and use the minimum value in the final result as the final location information LRA of the positioning terminal.

[0087] S7. Display the final location information LRA of the positioning terminal on the BIM map to obtain a location mapping that corresponds one to one in the real world.

[0088] S8. After each positioning base station is turned on, a synchronous communication network is formed, and the positioning terminal is connected to the synchronous communication network.

[0089] The time synchronization between the positioning base stations includes external synchronization and internal synchronization.

[0090] Among them, external synchronization relies on the second pulse of Beidou or GPS positioning module to achieve time synchronization between various positioning base stations.

[0091] Internal synchronization relies on the self-elected master node to send broadcast frames. After other positioning base stations detect the broadcast frames through synchronization, they maintain time synchronization with the master node.

[0092] Among them, the process of self-election of the master node for networking is: after the positioning base station is randomly turned on, the positioning base station that is turned on first searches for the broadcast frames sent by other positioning base stations within a fixed time. If it cannot be found, it will automatically switch the status to the master node and send broadcast frames; after other positioning base stations search for the broadcast frames of the master node, they will keep synchronization with the master node.

[0093] The specific process of the positioning terminal accessing the synchronous communication network is as follows:

[0094] After the positioning terminal searches for the broadcast frame sent by the positioning base station, it performs time synchronization and sends an access frame.

[0095] After receiving the access request from the positioning terminal, the positioning base station allocates an idle time slot.

[0096] The positioning terminal communicates with the positioning base station in the idle time slot, thus realizing the process of the positioning terminal accessing the synchronous communication network.

[0097] After the positioning terminal is connected to the synchronous communication network, it can conduct two-way communication with the behavior base station in the allocated time slot. On the one hand, the positioning terminal can upload the location information to the positioning base station for the background system to call; on the other hand, the positioning base station can also send the accusation short message to the positioning terminal.

[0098] S9. The location background management system displays the final location information of the positioning terminal in real time on the user interface with BIM as the reference map, so as to complete the recording and tracking of the movement trajectory of the positioning terminal, and use the synchronous communication network to complete the sending or receiving of short messages to the positioning terminal.

[0099] like Figure 3 As shown, the location fingerprint positioning method provided by the present application adopts a high-sensitivity, low-power LPWAN (Low-Power Wide-Area Network) positioning base station to realize wireless signal fingerprint collection and communication, thereby reducing the number of positioning base stations deployed; wireless interconnection is realized between the positioning base station and the positioning terminal, which can avoid the wired connection of the traditional positioning base station, and can also realize the simultaneous transmission of positioning and information; the location fingerprint positioning method provided by the present application adopts a combination of TOA ranging and fingerprint matching, which can significantly improve the positioning accuracy; the location fingerprint positioning method provided by the present application combines positioning information with BIM, which can meet the needs of indoor positioning.

[0100] The location fingerprint positioning method provided in this application is intended to solve the problem that many commercial indoor buildings currently require a large amount of construction and renovation inside the building when positioning information is needed.

[0101] In order to solve the problem of limited coverage of positioning base stations and inability to cover across rooms and floors in current positioning methods, a low-power wide area network (LPWAN) technology with strong penetration and high sensitivity is adopted. Each node uses a synchronous method to complete mesh connection and networking, which can solve the problem of device communication in complex indoor environments.

[0102] It should be noted that the LPWAN communication module adopts a high-spread spectrum Chirp debugging method, which is a low-rate and high-sensitivity communication method with a sensitivity of up to -140dBm (1W transmission power can penetrate 20 floors of concrete structure). A small number of modules can achieve signal coverage of multi-story building spaces.

[0103] In response to the problem in current positioning methods that the positioning base station requires a wired deployment connection, the location fingerprint positioning method provided in this application uses a wireless self-organizing network communication technology with integrated interaceptive communication to carry out two-way communication between the positioning base station and the positioning terminal; it can not only solve the complex problems of wired deployment, but also realize the integration of positioning perception and short message communication.

[0104] The location fingerprint positioning method provided in this application mainly involves two aspects: synchronous networking and synaesthesia integrated design:

[0105] For synchronous networking, after the LPWAN communication module is turned on, it will automatically elect a central node as the standard time point. The central node periodically sends broadcast frames to distribute time synchronization information, and other communication modules complete the synchronization and access process by detecting the broadcast frames.

[0106] For synaesthesia integration, in the frame format design of the synchronous communication network, positioning information and data transmission information are placed in one frame format to complete the synchronous transmission of data and position.

[0107] The location fingerprint positioning method provided in this application adopts BIM technology to integrate the positioning information with the BIM map to achieve a complete indoor positioning function.

[0108] The communication modulation method used in the location fingerprint positioning method provided by this application has the characteristics of high sensitivity and the ability to penetrate walls and the ground. No wired connection is required between positioning base stations, so the deployment of positioning base stations is flexible and simple, the number required is greatly reduced, and the cost is greatly reduced. Since there is no need to modify the building, it also protects the privacy of users inside the building.

[0109] All devices used in the location fingerprint positioning method provided in this application adopt a dedicated wireless communication method, do not rely on the operator network, information security is guaranteed, and the function of information communication can be realized under the condition of perceived positioning.

[0110] The positioning accuracy of LPWAN is 2 to 5 meters, and the location information is integrated with BIM, which can meet most of the indoor positioning needs.

[0111] Based on the location fingerprint positioning method provided by the present application, the present application also provides a location fingerprint positioning system, which includes a positioning base station, a positioning terminal, a processor, a BIM library and a location background management subsystem. Among them, the positioning base station is deployed outside the building, and a synchronous communication network is formed between the positioning terminal and the positioning base station.

[0112] The positioning terminal is used to collect offline and real-time positions and send the collected information to the processor. The processor is used to build a position fingerprint library based on the offline position information, estimate the position of the positioning terminal based on the distance between the positioning terminal and the positioning base station and calculate the weighted value, calculate the final real-time position information of the positioning terminal based on the real-time position information, and match the final real-time position information with the position fingerprint library to output the final position information of the positioning terminal.

[0113] The BIM library is used to mark and display the location information of positioning base stations and positioning terminals.

[0114] The location background management subsystem is used to record and track the movement trajectory of the positioning terminal, and use the synchronous communication network to send or receive short messages to the positioning terminal.

[0115] It should be noted that the location fingerprint positioning system provided in the above embodiment is only illustrated by the division of the above program modules. In actual applications, the above processing can be assigned to different program modules as needed, that is, the internal structure of the location fingerprint positioning system is divided into different program modules to complete all or part of the processing described above. In addition, the location fingerprint positioning system provided in the above embodiment and the location fingerprint positioning method embodiment belong to the same concept. The specific implementation process is detailed in the method embodiment and will not be repeated here.

[0116] In an exemplary embodiment, the embodiment of the present application further provides a storage medium, which is a computer-readable storage medium, for example, a memory including a computer program, and the above-mentioned computer program can be executed by a processor to complete the steps in the aforementioned position fingerprint positioning method.

[0117] The above-mentioned embodiments of the present application can be implemented in various hardware, software coding or a combination of the two. For example, the embodiments of the present application can also be a program code for executing the above method in a data signal processor. The present application can also relate to the various functions performed by a computer processor, a digital signal processor, a microprocessor or a field programmable gate array. The above-mentioned processor can be configured according to the present application to perform specific tasks, which are completed by executing a machine-readable software code or firmware code that defines the specific method disclosed by the present application. The software code or firmware code can be developed into different program languages ​​and different formats or forms. It is also possible to compile software codes for different target platforms. However, the different code styles, types and languages ​​of the software code for performing tasks according to the present application and other types of configuration codes do not depart from the spirit and scope of the present application.

[0118] The above description is only an illustrative specific implementation manner of the present application. Without departing from the concept and principle of the present application, any equivalent changes and modifications made by any technician in the field should fall within the scope of protection of the present application.

Claims

1. A location fingerprint positioning method, characterized in that: The following steps are involved: Deploy the positioning base station outside the building and mark the location information of the positioning base station on the BIM map; The positioning terminal collects offline positions and uses the collected offline position information to build a position fingerprint library; Estimate the location of the positioning terminal according to the distance between the positioning terminal and the positioning base station; According to the location of the positioning terminal, calculate the distance ratio of the collection points at the upper, lower, left, right, front and back positions of the positioning terminal in space, and use the distance ratio as the subsequent weighted value; The positioning terminal collects real-time position information and optimizes the collected real-time position information using the Gaussian distribution function to obtain the final real-time position information; Calculate the Euclidean distance between the final real-time location information and the optimized data of each location collection point in the location fingerprint library; and weight the Euclidean distances corresponding to each location collection point above, below, left, right, front, and back of the location of the positioning terminal, and use the minimum value of the final result as the final location information of the positioning terminal; The final location information of the positioning terminal is displayed in the BIM map to obtain a one-to-one corresponding location mapping with the real world to complete the positioning of the positioning terminal.

2. The position fingerprint positioning method according to claim 1, characterized in that: The following steps are also included: After each positioning base station is turned on, a synchronous communication network is formed, and the positioning terminal is connected to the synchronous communication network; The location background management system displays the final location information of the positioning terminal in real time on the user interface with BIM as the reference map, so as to record and track the movement trajectory of the positioning terminal, and use the synchronous communication network to send or receive short messages to the positioning terminal.

3. The position fingerprint positioning method according to claim 1 or 2, characterized in that: The specific process of the positioning terminal collecting offline positions and building a position fingerprint library using the collected offline position information is as follows: Set the location collection point LA according to the preset distance interval i , where i = 1, 2, ..., n, n represents the number of location collection points; Place the positioning terminal at the location collection point LA i , record the positioning base station t received by the positioning terminal j The strength of the transmitted signal RSSI j1 ,RSSI j2 ,......,RSSI jr and bit error rate ERR j1 ,ERR j2 ,......,ERR jr , where j = 1, 2, ..., k, k represents the number of positioning base stations; Using Gaussian distribution function to locate base station t j The strength of the transmitted signal RSSI j1 ,RSSI j2 ,......,RSSI jr and bit error rate ERR j1 ,ERR j2 ,......,ERR jr After optimization, the signal strength and bit error rate are (RSSIt j ,ERRt j ), then the location information of the location collection point LAi is marked as LA i (RSSIit1, ERRit1; RSSIit2, ERRit2; ...; RSSIit j , ERRt j ; ... ; RSSIit k , ERRit k ), where (RSSIit j , ERRit j ) represents the jth positioning base station t received by the i-th location collection point j The value after optimizing the strength of the transmitted signal and the received bit error rate; The optimized data of each location collection point is placed in a data table to obtain a location fingerprint library; wherein the location fingerprint library is in the form of:

4. The position fingerprint positioning method according to claim 1 or 2, characterized in that: The specific process of estimating the location of the positioning terminal according to the distance between the positioning terminal and the positioning base station is as follows: The TOA ranging method is used to estimate the distance between the positioning terminal and at least three positioning base stations, where the distance estimation formula is: Where A represents the absolute value of RSSI when the positioning terminal is 1 meter away from the positioning base station, α represents the environmental attenuation factor, and d represents the estimated distance; Using the spatial three-point positioning algorithm, the location L1 of the positioning terminal is estimated according to the distance between the positioning terminal and each base station. The specific process is as follows: Assume that the location coordinates of the positioning terminal are (x, y, z); It is known that the position coordinates of the first positioning base station are (x1, y1, z1), the position coordinates of the second positioning base station are (x2, y2, z2), and the position coordinates of the third positioning base station are (x3, y3, z3); According to the distance estimation formula, the distances between the positioning terminal and the first positioning base station, the second positioning base station and the third positioning base station are d1, d2, and d3 respectively. Then, the relationship equations between the distances between the positioning terminal and the positioning base station and the position coordinates of the positioning terminal and the position coordinates of the positioning base station are as follows: The position coordinates of the positioning terminal are calculated based on the relationship equation group.

5. The position fingerprint positioning method according to claim 4, characterized in that: The specific process of calculating the distance ratio of the collection points at the upper, lower, left, right, front and rear positions of the positioning terminal in space according to the position of the positioning terminal is as follows: Set the distance D between adjacent location collection points, and the distance between location L1 and each location collection point is dc1, dc2, dc3, dc4, dc5, dc6, then the distance ratios R1, R2, R3, R4, R5, R6 are:

6. The position fingerprint positioning method according to claim 2, characterized in that: The time synchronization between the positioning base stations includes external synchronization and internal synchronization; The external synchronization is to achieve time synchronization between various positioning base stations by relying on the second pulse of Beidou or GPS positioning module; The internal synchronization relies on a self-elected master node to send a broadcast frame, and other positioning base stations detect the broadcast frame through synchronization and maintain time synchronization with the master node.

7. The position fingerprint positioning method according to claim 6, characterized in that: The process of self-selecting the master node to form a network is as follows: After the positioning base stations are randomly powered on, the first one to be powered on will search for broadcast frames sent by other positioning base stations within a fixed time. If it cannot be found, it will automatically switch its status to the master node and send broadcast frames. After searching for the broadcast frames of the master node, other positioning base stations will synchronize with the master node.

8. The position fingerprint positioning method according to claim 7, characterized in that: The specific process of the positioning terminal accessing the synchronous communication network is: After the positioning terminal searches for the broadcast frame sent by the positioning base station, it performs time synchronization and sends an access frame; After receiving the access request from the positioning terminal, the positioning base station allocates an idle time slot; The positioning terminal communicates with the positioning base station in the idle time slot.

9. A position fingerprint positioning system, characterized in that: A location fingerprint positioning method as described in any one of claims 1 to 8 is adopted, comprising a positioning base station, a positioning terminal, a processor, a BIM library and a location background management subsystem; The positioning base station is deployed outside the building, and a synchronous communication network is formed between the positioning terminal and the positioning base station; The positioning terminal is used to collect offline position and real-time position, and send the collected information to the processor; The processor is used to build a location fingerprint library according to the offline location information, estimate the location of the positioning terminal according to the distance between the positioning terminal and the positioning base station and calculate the weighted value, and is also used to calculate the final real-time location information of the positioning terminal according to the real-time location information, and is also used to match the final real-time location information with the location fingerprint library to output the final location information of the positioning terminal; The BIM library is used to annotate and display the location information of the positioning base station and the positioning terminal.

10. The position fingerprint positioning system according to claim 9, characterized in that: It also includes a location background management subsystem, which is used to record and track the movement trajectory of the positioning terminal and use the synchronous communication network to send or receive short messages to the positioning terminal.

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