Positioning method, device, system and medium based on UWB downlink arrival time difference

Abstract

The present disclosure provides a positioning method, device, system and medium based on UWB downlink arrival time difference. The method is applied to a tag device and may include: receiving a ranging message sent by a positioning base station and recording a receiving timestamp of the ranging message, wherein the positioning base station includes a main base station and at least three slave base stations within its coverage range; parsing the ranging message to obtain fixed coordinate information of the main base station and the slave base station, sending and receiving time difference information of the ranging message and a clock compensation coefficient; obtaining a preliminary arrival time difference according to the receiving timestamp and the sending and receiving time difference information of the ranging message; performing clock drift compensation on the preliminary arrival time difference according to the time reference of the main base station and the clock compensation coefficient to obtain a precise arrival time difference; and obtaining the positioning coordinates of the tag device itself according to the precise arrival time difference and the fixed coordinate information of the main base station and the slave base station.

Description

Technical Field

[0001] The embodiments of the present disclosure relate to the field of UWB communication technology, and in particular to a positioning method, device, system and medium based on UWB downlink arrival time difference. Background Art

[0002] Ultra Wide Band (UWB) technology is a carrier-free communication technology that uses non-sinusoidal narrow pulses in the nanosecond to microsecond range to transmit data. It can transmit extremely low-power signals over a wider spectrum. Therefore, UWB technology is widely used in application scenarios such as data transmission, positioning and ranging.

[0003] In the UWB-based positioning system, Time Difference of Arrival (TDOA) is a high-precision positioning and tracking positioning method used to determine the time difference between a signal or an object arriving at two or more receivers. TDOA positioning includes two modes, namely downlink TDOA and uplink TDOA. In the downlink TDOA positioning mode, at least four positioning base stations are required to complete the positioning of the tag device, wherein the four positioning base stations form three pairs of base station pairs, and each pair of base station pairs interacts with each other. When the tag device receives the message, it calculates the time difference from the base station pair, that is, the TDOA value, and then uses the fixed coordinate positions of different positioning base stations and the time difference of the base station pair to calculate the coordinates of the tag device, thereby realizing the positioning function of the tag device. In this mode, the tag device needs to have strong computing power, and it is also a test for power consumption.

[0004] At present, in the UWB downlink TDOA positioning solution, in order to obtain accurate TDOA values, strict clock synchronization is required between positioning base stations so that positioning signals can be sent simultaneously at the same time. Otherwise, the obtained TDOA value is inaccurate, which in turn leads to inaccurate positioning of the tag device. In addition, it is difficult to maintain clock synchronization between positioning base stations in the UWB system. Using external technology to synchronize the clocks between positioning base stations will increase additional costs. Summary of the invention

[0005] In view of this, the embodiments of the present disclosure are intended to provide a positioning method, device, system and medium based on UWB downlink arrival time difference, where the tag device only receives the ranging message of the positioning base station and does not send the ranging message, thereby achieving low power consumption operation. The initial arrival time difference is drift compensated according to the clock compensation coefficient, thereby improving the accuracy of the positioning system.

[0006] The technical solution of the embodiment of the present disclosure is implemented as follows:

[0007] In a first aspect, an embodiment of the present disclosure provides a positioning method based on UWB downlink arrival time difference, the method is applied to a tag device, and the method includes:

[0008] Receive a ranging message sent by a positioning base station, and record a receiving timestamp of the ranging message, wherein the positioning base station includes a primary base station and at least three secondary base stations within its coverage area;

[0009] Parsing the ranging message to obtain fixed coordinate information of the master base station and the slave base station, time difference information of sending and receiving the ranging message, and a clock compensation coefficient;

[0010] Obtaining a preliminary arrival time difference according to the receiving timestamp and the sending and receiving time difference information of the ranging message;

[0011] According to the time reference of the primary base station and the clock compensation coefficient, clock drift compensation is performed on the preliminary arrival time difference to obtain an accurate arrival time difference;

[0012] The positioning coordinates of the tag device itself are obtained according to the precise arrival time difference and the fixed coordinate information of the master base station and the slave base station.

[0013] In a second aspect, an embodiment of the present disclosure provides a positioning method based on UWB downlink arrival time difference, the method is applied to a primary base station, and the method includes:

[0014] Sending the divided timing information to the slave base station so that the slave base station acquires the corresponding ranging cycle and ranging time slot in the allocated ranging block;

[0015] In a ranging cycle, completing the interaction process of ranging messages with the slave base station in the ranging cycle and ranging time slot, and obtaining the sending and receiving time difference information of the ranging message with the slave base station;

[0016] Acquire a clock compensation coefficient according to the sending and receiving time difference information of the ranging message;

[0017] The clock compensation coefficient is sent to a tag device within the coverage of the primary base station, so that the tag device performs clock drift compensation based on the clock compensation coefficient.

[0018] In a third aspect, an embodiment of the present disclosure provides a positioning method based on UWB downlink arrival time difference, the method is applied to a slave base station, and the method includes:

[0019] receiving timing information sent by the primary base station, and obtaining, according to the timing information, a ranging cycle and a ranging time slot for interacting with the primary base station in a ranging message;

[0020] In a ranging cycle, in the ranging cycle and the ranging time slot, the interaction of the ranging message with the primary base station is completed, and the sending and receiving time difference information of the ranging message is recorded;

[0021] The fixed coordinate information, clock compensation coefficient and the sending and receiving time difference information of the ranging message are sent to the tag device within its coverage range, so that the tag device obtains the arrival time difference.

[0022] In a fourth aspect, an embodiment of the present disclosure provides a label device, the label device comprising: a receiving part, a parsing part, a first obtaining part, a compensation part and a second obtaining part; wherein,

[0023] The receiving part is configured to receive a ranging message sent by a positioning base station and record a receiving timestamp of the ranging message, wherein the positioning base station includes a primary base station and at least three secondary base stations within its coverage area;

[0024] The parsing part is configured to parse the ranging message to obtain the fixed coordinate information of the master base station and the slave base station, the sending and receiving time difference information of the ranging message, and the clock compensation coefficient;

[0025] The first obtaining part is configured to obtain a preliminary arrival time difference according to the receiving timestamp and the sending and receiving time difference information of the ranging message;

[0026] The compensation part is configured to perform clock drift compensation on the preliminary arrival time difference according to the time reference of the primary base station and the clock compensation coefficient to obtain a precise arrival time difference;

[0027] The second obtaining part is configured to obtain the positioning coordinates of the tag device itself according to the precise arrival time difference and the fixed coordinate information of the master base station and the slave base station.

[0028] In a fifth aspect, an embodiment of the present disclosure provides a main base station device, the main base station device comprising: a division part, a ranging part, an acquisition part and a first sending part; wherein,

[0029] The dividing part is configured to send the divided timing information to the slave base station, so that the slave base station learns the corresponding ranging cycle and ranging time slot in the allocated ranging block;

[0030] The ranging part is configured to complete the interaction process of ranging messages with the slave base station in the ranging cycle and ranging time slot within a ranging period, and obtain the sending and receiving time difference information of the ranging message with the slave base station;

[0031] The acquisition part is configured to acquire a clock compensation coefficient according to the time difference information of sending and receiving the ranging message;

[0032] The first sending part is configured to send the clock compensation coefficient to a tag device within the coverage of the main base station, so that the tag device performs clock drift compensation based on the clock compensation coefficient.

[0033] In a sixth aspect, an embodiment of the present disclosure provides a slave base station device, the slave base station device comprising: a learning part, a recording part, and a second sending part; wherein,

[0034] The acquiring part is configured to receive timing information sent by the primary base station, and acquire the ranging cycle and ranging time slot for the ranging message interaction with the primary base station according to the timing information;

[0035] The recording part is configured to complete the interaction of ranging messages with the primary base station in the ranging cycle and ranging time slot within a ranging period, and record the sending and receiving time difference information of the ranging message;

[0036] The second sending part is configured to send its own fixed coordinate information, clock compensation coefficient and the sending and receiving time difference information of the ranging message to the tag device within its coverage range, so that the tag device obtains the arrival time difference.

[0037] In a seventh aspect, an embodiment of the present disclosure provides a positioning system based on UWB downlink arrival time difference, the positioning system comprising: a master base station, one or more slave base stations and one or more tag devices; wherein,

[0038] The one or more tag devices are configured to perform the steps of the positioning method based on UWB downlink arrival time difference according to the first aspect;

[0039] The primary base station is configured to perform the steps of the positioning method based on UWB downlink arrival time difference according to the second aspect;

[0040] The one or more slave base stations are configured to execute the steps of the positioning method based on UWB downlink arrival time difference described in the third aspect.

[0041] In an eighth aspect, an embodiment of the present disclosure provides a computer storage medium, wherein the computer storage medium stores a positioning program based on UWB downlink arrival time difference, and when the positioning program based on UWB downlink arrival time difference is executed by at least one processor, the steps of the positioning method based on UWB downlink arrival time difference described in the first aspect, the second aspect, or the third aspect are implemented.

[0042] The disclosed embodiments provide a positioning method, device, system and medium based on UWB downlink arrival time difference. In the positioning process of the tag device, the tag device only receives the ranging message sent by the positioning base station without sending the ranging message, so that the tag device can achieve low power consumption operation. In the ranging process of the positioning base station, the tag device records the receiving timestamp of each ranging message, and obtains the preliminary arrival time difference based on the recorded receiving timestamp and the fixed coordinate information of the main base station and the slave base station obtained by parsing, and the sending and receiving time difference information of the ranging message. The preliminary arrival time difference is compensated for clock drift according to the time reference of the main base station and the clock compensation coefficient sent by the main base station and the slave base station to obtain the precise arrival time difference, thereby improving the accuracy of the positioning system. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 A schematic diagram of the composition of a positioning system provided in an embodiment of the present disclosure;

[0044] Figure 2 A schematic diagram of the composition of a network node device provided in an embodiment of the present disclosure;

[0045] Figure 3 A network structure diagram for UWB downlink TDOA positioning;

[0046] Figure 4 A flowchart of a positioning method based on UWB downlink arrival time difference provided in an embodiment of the present disclosure;

[0047] Figure 5 An example diagram of a network structure for UWB downlink TDOA positioning provided in an embodiment of the present disclosure;

[0048] Figure 6 A flowchart of message interaction for a tag device to monitor the distance measurement of a positioning base station provided in an embodiment of the present disclosure;

[0049] Figure 7 A schematic diagram of the message interaction timing for calculating TDOA provided in an embodiment of the present disclosure;

[0050] Figure 8 A flowchart of another positioning method based on UWB downlink arrival time difference provided in an embodiment of the present disclosure;

[0051] Fig. 9 A schematic diagram of the timing structure provided in the embodiment of the present disclosure;

[0052] Fig.10 A message interaction flow chart of a positioning base station measuring the distance of a tag device provided in an embodiment of the present disclosure;

[0053] Fig.11A flowchart of another positioning method based on UWB downlink arrival time difference provided in an embodiment of the present disclosure;

[0054] Fig.12 A schematic diagram of the composition of a label device provided in an embodiment of the present disclosure;

[0055] Fig.13 A schematic diagram of the composition of a main base station device provided in an embodiment of the present disclosure;

[0056] Fig.14 A schematic diagram of the composition of a slave base station device provided in an embodiment of the present disclosure. DETAILED DESCRIPTION

[0057] The technical solutions in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings in the embodiments of the present disclosure.

[0058] See also Figure 1 , which shows a schematic diagram of the positioning system 100 that can implement the embodiment of the present disclosure. It should be noted that Figure 1 The illustrated positioning system 100 is but one example of a possible system, and embodiments of the present disclosure may be implemented in any of a variety of systems as desired.

[0059] like Figure 1 As shown, the positioning system 100 includes: a master base station 11, one or more slave base stations. The embodiment of the present disclosure takes three slave base stations as an example, which are respectively identified as slave base stations 21, 22, 23, and one or more base stations within the signal coverage range of the above base stations (such as Figure 1In the present disclosure, five tag devices are taken as an example, which can be identified as Tag31, 32, 33, 34, and 35. In some non-limiting examples, the master base station 11, the slave base stations 21, 22, 23, and the tags 31, 32, 33, 34, and 35 can communicate wirelessly using any of a variety of wireless communication technologies, which may include UWB communication technology (for example, compliant with IEEE 802.15.4z), Wi-Fi (for example, IEEE 802.11), and / or other technologies based on WPAN or WLAN wireless communication for communication. In addition, the master base station 11 and the slave base stations 21, 22, 23 and one or more of the tags 31, 32, 33, 34, 35, and the slave base stations 21, 22, 23 and one or more of the tags 31, 32, 33, 34, 35 can also communicate via one or more additional wireless communication protocols, for example, any one of Bluetooth, Bluetooth Low Energy (BLE), near field communication (NFC), GSM, UMTS (WCDMA, TDSCDMA), LTE, LTE-Advanced (LTE-A), NR, 3GPP2 CDMA1000 (for example, 1xRTT, 1xEV-DO, HRPD, eHRPD), Wi-MAX, GPS, etc. The embodiments of the present disclosure mainly adopt the following methods: Figure 1 The UWB communication technology shown by the solid arrow is used for communication.

[0060] As an illustrative example and not limiting, Figure 1The tags 31, 32, 33, 34, and 35 shown in the figure can be specifically a printer, a personal digital assistant (PDA), a camera, a speaker system, or a wireless network. In addition, they also include mobile devices, cellular (cell) phones, smart phones, Session Initiation Protocol (SIP) phones, laptops, personal computers (PCs), notebooks, netbooks, smartbooks, tablet devices, and a wide variety of embedded systems, for example, corresponding to the "Internet of Things" (IoT). Additionally, the tag device can be a car or other transportation vehicle, a remote sensor or actuator, a robot or robotic device, a satellite radio, a Global Positioning System (GPS) device, an object tracking device, a drone, a multi-axis aircraft, a quadcopter, a remote control device, a consumer and / or wearable device (such as glasses), a wearable camera, a virtual reality device, a smart watch, a health or fitness tracker, a digital audio player, for example, an MP3 player, a camera, a game console, etc. Additionally, the tag device may also be a digital home or smart home device, such as home audio, video and / or multimedia devices, electrical appliances, vending machines, smart lighting devices, home security systems, smart meters, etc. Additionally, the tag device may also be a smart energy device, a security device, a solar panel or solar array, a municipal infrastructure device that controls electricity, lighting, water, etc., such as a smart grid; industrial automation and enterprise equipment; logistics controllers; agricultural equipment; military defense equipment, vehicles, aircraft, ships and weapons, etc.

[0061] based on Figure 1 The positioning system 100 shown, Figure 2 The composition of an exemplary network node device 200 capable of implementing a master base station 11, slave base stations 21, 22, 23, and tags 31, 32, 33, 34, and 35 is shown, including a processor 210, a memory 220, a wireless communication circuit 230, and a power supply 240; the components can be connected through various appropriate types of buses, such as a power bus, a control bus, and a status signal bus. The power supply 240 provides power to the components in the network node device 200.

[0062] In some examples, the processor 210 may be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components. The various methods, steps and logic block diagrams disclosed in the embodiments of the present disclosure may be implemented or executed. The general-purpose processor may be a microprocessor or the processor may be any conventional processor, etc. The contents disclosed in the embodiments of the present disclosure may be directly embodied as being executed by a hardware decoding processor, or may be executed by a combination of hardware and software modules in the decoding processor. The software module may be located in the memory 220.

[0063] In some examples, memory 220 may be a volatile memory or a nonvolatile memory, or may include both volatile and nonvolatile memories. Among them, the nonvolatile memory may be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. The volatile memory may be a random access memory (RAM), which is used as an external cache. By way of example and not limitation, many forms of RAM are available, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDRSDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous link dynamic random access memory (SLDRAM), and direct memory bus random access memory (DRRAM). The memory 220 of the systems and methods described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0064] In some examples, the wireless communication circuit 230 may include communication components capable of wireless communication using a variety of wireless communication standards or radio access technologies, such as Figure 2 The UWB communication component 231 shown in the figure is used to enable the network node device 200 to perform UWB communication and / or range measurement communication according to the 802.15.4 protocol. Of course, in other examples, the wireless communication circuit 230 may also include a communication component capable of wireless communication according to other communication protocols other than UWB, which will not be described in detail in this disclosure.

[0065] Combined with the above Figure 1 as well as Figure 2 In some examples, when any one of Tags 31, 32, 33, 34, and 35 needs to be located, the tag is usually required to receive UWB ranging messages from at least four positioning base stations, wherein the positioning base stations include a primary base station and at least three secondary base stations within its coverage area. Figure 3 The network structure diagram of UWB downlink TDOA positioning shown in the figure includes four positioning base stations, namely, a master base station 11, slave base stations 21, 22, and 23, and a tag device 35. The coordinate positions of the four positioning base stations are fixed. The four positioning base stations are grouped into three base station pairs, namely, a master base station 11 and a slave base station 21, a master base station 11 and a slave base station 22, and a master base station 11 and a slave base station 23. Each base station pair completes the UWB communication ranging process respectively. During the UWB communication ranging process, the tag device, such as Figure 1 Any one of the tags 31, 32, 33, 34, and 35 in the positioning system 100 shown, taking Tag 35 as an example, receives the ranging messages sent simultaneously by the four positioning base stations, and records the receiving timestamp of each ranging message, and calculates the arrival time difference of the three base station pairs according to the receiving timestamp, that is, the TDOA value, and lists three hyperbolic equations. Since the coordinates of the four positioning base stations are known, the coordinates of the tag device can be obtained by substituting them into the hyperbolic equations. Based on the above explanation, in the UWB communication ranging process, the tag device receives the ranging messages sent simultaneously by the four positioning base stations. In order to obtain an accurate TDOA value, it is necessary to maintain strict clock synchronization between the positioning base stations so that the ranging messages can be sent simultaneously at the same time point. Otherwise, the obtained TDOA value is inaccurate, which leads to inaccurate positioning of the tag device. Based on this, the embodiment of the present disclosure hopes to provide a positioning technology solution based on UWB downlink TDOA. This technical solution does not require strict clock synchronization between the positioning base stations, nor does it require the use of external synchronization technology, thereby reducing system costs. See. Figure 4 , which shows a positioning method based on UWB downlink arrival time difference provided by an embodiment of the present disclosure, which can be applied to Figure 1For any one of the tag devices 31, 32, 33, 34, 35 in the positioning system 100, the method may include:

[0066] S401: Receive a ranging message sent by a positioning base station, and record a receiving timestamp of the ranging message, wherein the positioning base station includes a primary base station and at least three secondary base stations within its coverage area;

[0067] S402: Parse the ranging message to obtain fixed coordinate information of the master base station and the slave base station, time difference information of sending and receiving the ranging message, and a clock compensation coefficient;

[0068] The fixed coordinate information is set when the master base station and slave base station systems are initialized and updated as needed. The time difference information of sending and receiving the ranging message is the time difference recorded by the slave base station when receiving the ranging message from the master base station and sending the response message. The clock compensation coefficient is a value used to correct the synchronization error between two or more clocks. In a system that requires high-precision time synchronization, due to the defects of the hardware clock, the clocks of different devices or nodes will deviate. The deviation is called clock drift. The clock compensation coefficient is a correction factor introduced to correct the clock drift.

[0069] S403: Obtaining a preliminary arrival time difference according to the receiving timestamp and the sending and receiving time difference information of the ranging message;

[0070] The preliminary arrival time difference is based on the fact that the propagation speed of signals (such as radio waves, sound waves, etc.) is constant in a uniform medium. It is used to determine the time difference when a signal arrives at two or more receivers. If a signal source (such as a master base station) sends a signal to multiple receivers (such as a slave base station or a tag device) at the same time, the time when the signal arrives at each receiver will be different due to the different distances between the receiver and the signal source. By measuring these time differences, the location of the signal source can be inferred.

[0071] S404: Perform clock drift compensation on the preliminary arrival time difference according to the time reference of the primary base station and the clock compensation coefficient to obtain a precise arrival time difference;

[0072] S405: Obtain the positioning coordinates of the tag device itself according to the precise arrival time difference and the fixed coordinate information of the master base station and the slave base station.

[0073] For the above technical solution, during the positioning process of the tag device, the tag device only receives the ranging message sent by the positioning base station instead of sending the ranging message, so that the tag device can achieve low power consumption operation. During the ranging process of the positioning base station, the tag device records the receiving timestamp of each ranging message, and obtains the preliminary arrival time difference based on the recorded receiving timestamp and the fixed coordinate information of the main base station and the slave base station obtained by parsing, and the sending and receiving time difference information of the ranging message. The preliminary arrival time difference is compensated for clock drift according to the time reference of the main base station and the clock compensation coefficient sent by the main base station and the slave base station to obtain the precise arrival time difference, thereby improving the accuracy of the positioning system.

[0074] against Figure 4 In some possible implementations of the technical solution shown, the receiving a ranging message sent by a positioning base station and recording a receiving timestamp of the ranging message include:

[0075] In a ranging cycle, receiving a Poll message and a Final message sent by a master base station among the positioning base stations;

[0076] In a ranging cycle, receiving a Response message sent from the base station;

[0077] The receiving timestamps of the received Poll message, Final message and Response message are recorded.

[0078] For the above implementation, see Figure 5 , which shows an example diagram of a network structure of UWB downlink TDOA positioning provided by an embodiment of the present disclosure, in which a network connection is established between positioning base stations and between positioning base stations and tag devices, and roles are assigned, combined with Figure 1 The positioning system 100 shown in the figure determines a master base station, namely the master base station 11 is responsible for initiating the ranging process and performing timing management, and designates other base stations as slave base stations, for example, slave base stations 21, 22, and 23 participate in the ranging process, are responsible for receiving the ranging message of the master base station 11, and reply to the ranging message in response at the specified timing, wherein the ranging message is only exchanged between positioning base stations, and the tag device only receives the ranging message exchanged between positioning base stations. Figure 5 In the network structure diagram shown in FIG. 1 , the master base station 11 and the slave base station 21, the master base station 11 and the slave base station 22, and the master base station 11 and the slave base station 23 form three pairs of base station pairs, and the distances between the master base station 11 and the slave base station 21 and the master base station 11 and the slave base station 22 are set respectively, as shown in FIG. Figure 5 The solid arrow portion shown in FIG. 1 sets the distance between the master base station 11 and the slave base station 21 to be , the distance between the master base station 11 and the slave base station 22 is , the distance between the master base station 11 and the slave base station 23 is . Set the distance between the positioning base station and any tag device, such as Figure 5 The dashed arrow portion shown in the figure, in this disclosure, taking the tag device 35 as an example, the distance between the main base station 11 and the tag device 35 is set to , the distance between the base station 21 and the tag device 35 is , the distance between the base station 22 and the tag device 35 is , the distance between the base station 23 and the tag device 35 is , which is used for the subsequent calculation of TDOA value.

[0079] In some examples, the recording of the reception timestamp of the ranging message is as follows: Figure 6 As shown, in the process of positioning the tag device, the tag device listens to each ranging message exchanged by all positioning base stations and records the receiving timestamp of each ranging message received, specifically including: in the example of the UWB ranging process, such as Figure 1 The main base station 11, slave base stations 21, 22, 23 and tag devices 31, 32, 33, 34, 35 in the positioning system 100 shown can be collectively referred to as ranging devices. The ranging messages involved in the UWB ranging process are Poll Message, Response Message and Final Message, namely Poll Message, Response Message and Final Message. The tag device receives each ranging message exchanged by all positioning base stations. Specifically, in a ranging cycle, it receives the Poll Message sent by the main base station 11 through broadcasting; receives the Response Message sent by the slave base station 21, the slave base station 22 and the slave base station 23 respectively; receives the Final Message sent by the main base station 11 through broadcasting, and records the receiving timestamp of each ranging message when receiving the ranging messages Poll Message, Response Message and Final Message respectively. The tag device receives the Poll Message sent by the main base station 11 and receives the Final Message sent by the main base station 11, which marks the end of a ranging cycle.

[0080] against Figure 4 In the technical solution shown, in some possible implementations, parsing the ranging message to obtain the fixed coordinate information of the master base station and the slave base station, the sending and receiving time difference information of the ranging message, and the clock compensation coefficient includes:

[0081] Parsing the Poll message sent by the primary base station to obtain the fixed coordinate information of the primary base station, the sending and receiving time difference information of the ranging message, and the clock compensation coefficient;

[0082] The Response message sent by the slave base station is parsed to obtain the fixed coordinate information of the slave base station, the sending and receiving time difference information of the ranging message, and the clock compensation coefficient.

[0083] For the above implementation, specifically, in a system based on the UWB downlink TDOA positioning method, the tag device needs to parse the ranging message from the positioning base station to obtain the necessary information, for example, Figure 1 The fixed coordinate information, the time difference information of sending and receiving the ranging message, and the clock compensation coefficient of the main base station 11 and the slave base stations 21, 22, and 23 in the positioning system 100 shown. In detail, the tag device parses the Poll Message sent by the main base station 11 to obtain the fixed coordinate information of the main base station 11. Then, the time difference information of sending and receiving the ranging message of the main base station 11 is extracted from the Poll Message. The time difference information of sending and receiving the ranging message of the main base station 11 includes the timestamp of the main base station 11 sending the message and the expected time difference information of receiving the response of the slave base stations 21, 22, and 23. The tag device obtains the clock compensation coefficient of the main base station 11 from the Poll Message to compensate for the clock drift between the main base station 11 and the tag device. The tag device parses the received Response Message sent by the slave base stations 21, 22, and 23 to obtain the fixed coordinate information of each slave base station. Extract the time difference information of the ranging messages of each slave base station in the Response Message, wherein the time difference information of the ranging messages includes the time difference between the timestamp of the Poll Message sent by the master base station received by the slave base station and the timestamp of the Response Message sent by the slave base station. Obtain the clock compensation coefficient of the slave base station in the Response Message to compensate for the clock drift of the slave base station. When receiving the Poll Message and the Response Message, the tag device records its own receiving timestamp.

[0084] It should be noted that clock drift refers to the long-term change between the frequency of a clock and its specified or expected frequency, which is usually caused by the influence of clock hardware, environmental conditions (such as temperature, humidity, power supply voltage fluctuations), or aging and wear of the clock. In applications that require high-precision time synchronization, such as communication systems, scientific measurements, global positioning systems, etc., clock drift can lead to inaccurate time measurement.

[0085] In some examples, after receiving the ranging message sent by the positioning base station, the tag device also needs to parse and obtain the clock compensation coefficients of the master base station and the slave base station. Taking the ranging message interaction between the master base station 11 and the slave base station 21 as an example, the master base station 11 records the time difference between sending the Poll Message and sending the Final Message as , and fill this value into the Poll Message, and record the time difference between receiving the Poll Message from base station 21 and receiving the Final Message as , and write this value into the Response Message, and record the time difference between the tag device receiving the Poll Message and receiving the Final Message as , the tag device parses and obtains the , , Parameter, which is the clock compensation coefficient.

[0086] against Figure 4 In some possible implementations of the technical solution shown, obtaining the preliminary arrival time difference according to the receiving timestamp and the sending and receiving time difference information of the ranging message includes:

[0087] Obtaining a preliminary time difference value of the tag device itself according to the recorded receiving timestamp of the ranging message received by the tag device itself;

[0088] Obtaining a preliminary time difference value between the master base station and the slave base station according to the time difference information of sending and receiving the ranging message obtained by parsing;

[0089] The preliminary arrival time difference is obtained according to the preliminary time difference value of the tag device itself and the preliminary time difference values ​​of the master base station and the slave base station.

[0090] For the above implementation, in some examples, the specific implementation method of obtaining the preliminary time difference of the tag device itself according to the recorded reception timestamp of the ranging message is: the tag device obtains the preliminary time difference of the Poll Message received from the main base station 11 and the ResponseMessage received from any one of the slave base stations 21, 22, 23 according to the recorded timestamp of the Poll Message received from the main base station 11 and the ResponseMessage received from any one of the slave base stations 21, 22, 23; the tag device obtains the preliminary time difference of the main base station 11 and the slave base stations 21, 22, 23 according to the recorded timestamp of the ResponseMessage received from the slave base stations 21, 22, 23 and the Final Message received from the main base station 11. Taking the ranging message interaction between the base station and the main base station 11 and the slave base station 21 as an example, see Figure 7 , which shows a schematic diagram of the message interaction timing for calculating TDOA provided by an embodiment of the present disclosure, the time difference information of the sending and receiving of the ranging message of the master base station and the slave base stations within its coverage, that is, Figure 7 The initial time difference and other parameters in are:

[0091] The time difference between when the main base station 11 sends the Poll Message and when the tag device receives the Final Message;

[0092] It is the time difference between when the tag device receives the Poll Message from the master base station 11 and when it receives the Response Message from the slave base station 21;

[0093] The time difference between when the tag device receives the Response Message from the slave base station 21 and when it receives the FinalMessage from the master base station 11;

[0094] The time difference between the time when the slave base station 21 receives the Poll Message from the master base station 11 and the time when the Response Message is sent. Currently, all UWB chips support the delayed sending function, that is, the sending time is calculated in advance and written into the register, and it is sent out after the system clock reaches the sending time. The slave base station 21 subtracts the timestamp when the Poll Message is received from the sending time in advance, and the difference is calculated. Fill in the Response Message, and the tag device will parse the Response Message to get the difference. ;

[0095] The time difference between the time when the primary base station 11 receives the Response Message from the secondary base station 21 and when it sends the Final Message. The principle is the same as ;

[0096] The time difference between the main base station 11 receiving the Response Message from the slave base station 21 and the tag device receiving the Response Message from the slave base station 21;

[0097] is the distance from the tag device to the main base station 11; is the distance from the tag device to the slave base station 21;

[0098] is the distance from the master base station 11 to the slave base station 21; The speed of light.

[0099] In some examples, obtaining a preliminary arrival time difference according to the preliminary time difference value of the tag device itself and the preliminary time difference values ​​of the master base station and the slave base station includes:

[0100] The relationship formula for obtaining the preliminary time difference value according to the preliminary time difference value of the tag device itself and the preliminary time difference values ​​of the master base station and the slave base station is:

[0101]

[0102] According to the difference The following equation is obtained:

[0103] (4)

[0104] Substituting formula (3) into formula (4), we get:

[0105] (5)

[0106] The preliminary arrival time difference TDOA value is obtained by sorting:

[0107] (6)

[0108] in, It is the time difference between when the tag device receives the Poll Message from the master base station and when it receives the Response Message from the slave base station; It is the time difference between when the tag device receives the Response Message from the slave base station and when it receives the Final Message from the master base station. The time difference between when the base station receives the Poll Message from the master base station and when it sends the Response Message; The time difference between the master base station receiving the Response Message from the slave base station and sending the Final Message. is the distance from the tag device to the main base station; is the distance from the tag device to the slave base station; The speed of light.

[0109] against Figure 4 In some possible implementations of the technical solution shown, the clock drift compensation is performed on the preliminary arrival time difference according to the time reference of the primary base station and the clock compensation coefficient to obtain the precise arrival time difference, including:

[0110] Obtain the clock drift of the slave base station and the tag device according to the acquired time difference information of sending and receiving the ranging messages of the master base station and the slave base station and the receiving timestamp of the ranging message recorded by the tag device;

[0111] The clock drift is compensated according to the clock compensation coefficient to obtain an accurate arrival time difference.

[0112] In some examples, after obtaining the time difference information of the transmission and reception of the ranging message of the master base station and the slave base station, the specific implementation of obtaining the clock drift of the slave base station and the tag device in combination with the reception timestamp of the ranging message recorded by the tag device is as follows: For example, the master base station carries a reference clock drift in the Poll Message, and the reference clock drift is obtained based on the high-precision crystal oscillator measurement of the master base station. In some examples, the clock drift of the slave base station and the tag device is obtained based on the time difference information and the reception timestamp obtained from the ranging message. The clock drift of the slave base station and the tag device is specifically the aforementioned time difference value , as well as .

[0113] The preliminary arrival time difference calculated in the above step S403 is based on the assumption that the clocks between all positioning base stations and tag devices are exactly the same. In reality, the crystal oscillator of each base station is different, which will lead to crystal oscillator errors between nodes. Therefore, there must be clock drift between the positioning base station and the tag device, and clock drift compensation needs to be performed between each node. Usually the crystal oscillator of each node is fixed, so the clock drift is also fixed, so it only needs to be compensated once within a certain period of time. It should be noted that the crystal oscillator of the main base station is usually measured in frequency deviation, for example, one part per million. A high-precision crystal oscillator can provide a smaller frequency deviation, thereby ensuring the accuracy of time measurement.

[0114] When the tag device obtains , , After the parameter, i.e., the clock compensation coefficient, is set, the clock offset compensation can be performed in the next ranging cycle to obtain the precise arrival time difference. In detail, in some examples, all nodes in the system use Figure 1 The main base station 11 in the positioning system 100 shown in the figure performs drift compensation for the reference time reference, and obtains the TDOA value after drift compensation according to formula (6), that is, the precise arrival time difference is:

[0115] (7)

[0116] Rearranging the above equation to obtain the exact TDOA value is:

[0117] (8)

[0118] in, The time difference between the primary base station sending the Poll Message and sending the Final Message; It is the time difference between the base station receiving the Poll Message and receiving the Final Message; It is the time difference between when the tag device receives the PollMessage and when it receives the FinalMessage. It is the time difference between when the tag device receives the PollMessage from the master base station and when it receives the Response Message from the slave base station; It is the time difference between when the tag device receives the Response Message from the slave base station and when it receives the Final Message from the master base station. The time difference between receiving the Poll Message from the master base station and sending the Response Message from the slave base station; The time difference between the master base station receiving the Response Message from the slave base station and sending the Final Message. is the distance from the tag device to the main base station; is the distance from the tag device to the slave base station; The speed of light.

[0119] For the above example, ideally, , , The parameter values ​​of are the same, but due to the existence of clock drift, there must be deviations between the three. In the clock drift compensation process, it is only necessary for the crystal oscillator accuracy of the main base station 11 to be relatively high. Therefore, when the main base station 11 is used as the time reference standard, the specific operation process of the clock drift compensation is: As the benchmark value, combined Figure 7 From the message interaction timing diagram for calculating TDOA shown in the figure, we can see that , are the measured time difference of the tag device, multiplied by the correction coefficient , that is, the clock compensation coefficient can be converted into the time reference of the main base station 11. is the measured time difference from base station 21, multiplied by the correction factor It can be converted into the time base of the main base station 11. The measured time difference of the primary base station 11 does not need to be corrected.

[0120] against Figure 4 In some possible implementations of the technical solution shown in FIG. 1 , the positioning coordinates of the tag device itself are obtained according to the precise arrival time difference and the fixed coordinate information of the master base station and the slave base station. Specifically, in combination with Figure 7 The base station shown calculates the TDOA value for the main base station 11 and the slave base station 21. The positioning principle of the base station for the main base station 11 and the slave base station 22, and the main base station 11 and the slave base station 23 for the tag device is the same as the positioning process of the base station for the main base station 11 and the slave base station 21. After obtaining three TDOA values, three hyperbolic equations are listed to calculate the distance between the tag device and the positioning base station, that is, the relative position of the tag device and at least four positioning base stations. According to the fixed coordinate information of the positioning base station and the relative position, the positioning coordinates of the tag device can be calculated.

[0121] Based on the same inventive concept as the above technical solution, see Figure 8 , which shows another positioning method based on UWB downlink arrival time difference provided by the embodiment of the present disclosure, which can be applied to Figure 1 In the main base station 11 of the positioning system 100 shown, the method may include:

[0122] S801: Sending the divided timing information to the slave base station, so that the slave base station acquires the corresponding ranging cycle and ranging time slot in the allocated ranging block;

[0123] S802: within a ranging cycle, completing the ranging message interaction process with the secondary base station in the ranging cycle and ranging time slot, and obtaining the sending and receiving time difference information of the ranging message with the secondary base station;

[0124] S803: Obtaining a clock compensation coefficient according to the sending and receiving time difference information of the ranging message;

[0125] S804: Send the clock compensation coefficient to a tag device within the coverage of the primary base station, so that the tag device performs clock drift compensation based on the clock compensation coefficient.

[0126] For the above technical solution, network connections are established between positioning base stations and between positioning base stations and tag devices to build a positioning network for tag devices. The base station pair between the main base station and any one of the slave base stations sends timing information to all slave base stations through the communication connection. Within one ranging cycle, the interaction process of ranging messages is completed with the slave base stations respectively according to the timing information. The main base station and the slave base station record the timestamp of the ranging message, obtain the sending and receiving time difference information of the ranging message and the clock compensation coefficient, and send the clock compensation coefficient to the tag device so that the tag device performs drift compensation for the initial arrival time difference, thereby improving the accuracy of positioning the tag device.

[0127] against Figure 8 In some possible implementations of the technical solution shown in FIG. 1 , the divided timing information is sent to the slave base station so that the slave base station learns the corresponding ranging cycle and ranging time slot in the allocated ranging block. Specifically, the master base station 11 is responsible for managing the division of the timing information of the entire system, see Fig. 9 , which shows a schematic diagram of the timing structure composition provided by an embodiment of the present disclosure, dividing the timing into Block, Round and Slot, setting a Block to contain Nround (Number Round Per Block) Rounds, a Round to contain Nslot (Number Slot Per Round) Slots, and a Slot period is set to Tslot (time slot period, for example, 2ms); then the time length of a single Round is Tslot×Nslot, and the time length of a single Block is Tslot×Nslot×Nround.

[0128] It should be noted that the timing information may specifically be the slots allocated to the master base station itself and each slave base station in a round, so that the master base station and the slave base station complete the interaction of ranging messages in the corresponding slots to obtain the corresponding ranging results. Figure 1 The interaction of ranging messages between the master base station and the slave base stations in the positioning system 100 shown in the figure needs to be reasonably allocated in time sequence, and the number of slots in each round needs to ensure that the master base station can complete the interaction of ranging messages with all the slave base stations. Fig. 9As shown in the timing structure diagram, it can be seen that within a Round, for the master base station 11, Slot0 is used to send the Poll Message, Slot1-Slot3 are used to receive the Response Message of each slave base station, and Slot4 is used to send the Final Message.

[0129] against Figure 8 In the technical solution shown, after completing the division and sending of the timing information through the above example, the positioning base station will complete the ranging message interaction for a tag device within one round. Through the ranging process reflected by the ranging message interaction, the positioning base station respectively records the timestamp of the ranging message interaction and obtains the sending and receiving time difference information of the ranging message of the positioning base station. In order to clearly explain the technical solution, the following roles or technical terms are defined for the UWB ranging process: The ranging device that defines and controls the ranging parameters by sending Poll Messages in the ranging control cycle can be defined as the controller, for example, Figure 1 The main base station 11 in the positioning system 100 shown in the figure; the ranging devices that use the ranging parameters received from the controller and respond can be defined as controlled devices, such as slave base stations 21, 22, and 23. As the controller of the UWB ranging process, the main base station 11 performs ranging on the tag device within the ranging cycle allocated to itself. The detailed process is as follows Fig.10As shown, first, the main base station 11 sends a Poll Message in a broadcasting manner in the Slot0 time slot allocated to itself to start the ranging process, wherein the Poll Message carries the ranging block index, ranging cycle index and time slot index allocated to itself. Secondly, in the Slot1-Slot3 time slots allocated to itself, the Response Message sent by each slave base station is received; after receiving the Poll Message, the slave base stations 21, 22, and 23 align their own timing with the main base station 11, and send Response Messages in their respective timing allocations. The slave base stations fill in specific parameters in the Response Message, such as the time difference between the time of sending the Response Message and the time of receiving the Poll Message, and the fixed coordinate information of the slave base station. Accordingly, the main base station 11 receives the Response Messages sent by the slave base stations 21, 22, and 23 in the Slot1-Slot3 time slots allocated to itself. Then, the master base station 11 broadcasts the Final Message in the Slot4 time slot allocated to itself; after receiving the Response Messages from all slave base stations, the master base station 11 sends the Final Message, marking the end of a ranging cycle. Each positioning base station records the timestamp when sending and receiving ranging messages, maintains its own location information, and transmits this information so that the tag device can perform subsequent TDOA calculations and finally determine the location of the tag device.

[0130] Based on the same inventive concept as the above technical solution, see Fig.11 , which shows another positioning method based on UWB downlink arrival time difference provided by the embodiment of the present disclosure, which can be applied to Figure 1 In any of the slave base stations 21, 22, 23 in the positioning system 100 shown, the method may include:

[0131] S1101: Receive timing information sent by a primary base station, and acquire a ranging cycle and a ranging time slot for ranging message interaction with the primary base station according to the timing information;

[0132] S1102: In a ranging cycle, in the ranging cycle and the ranging time slot, completing the interaction of ranging messages with the primary base station, and recording the sending and receiving time difference information of the ranging message;

[0133] S1103: Send its own fixed coordinate information, clock compensation coefficient and the sending and receiving time difference information of the ranging message to the tag device within its coverage range, so that the tag device obtains the arrival time difference.

[0134] For the above technical solution, the master base station is responsible for the timing coordination of the entire system, and the slave base station needs to synchronize its own operations based on this information. The slave base station determines the specific ranging cycle and ranging time slot for the ranging message interaction with the master base station based on the received timing information. The slave base station completes the ranging message interaction with the master base station in the allocated ranging cycle and ranging time slot to obtain the time difference information of the ranging message. When the slave base station is initialized, it obtains its own fixed coordinate information, and obtains the clock compensation coefficient based on the synchronization with the master base station to compensate for the existing clock deviation. The fixed coordinate information, clock compensation coefficient and time difference information of the ranging message are sent to the tag device so that the tag device obtains all the information required for the initial arrival time difference, thereby ensuring that the tag device obtains accurate positioning information and improving the accuracy of the entire positioning system.

[0135] For the above Figure 8 , Fig.11 The technical solutions and examples shown are similar to those mentioned above. Figure 4 The technical solutions shown belong to the same inventive concept, therefore, the above Figure 8 , Fig.11 For details of the technical solutions and examples shown in the drawings that are not described in detail, please refer to the above Figure 4 The description of the technical solution shown in the figure is not repeated in the embodiments of the present disclosure.

[0136] Based on the same inventive concept as the above technical solution, see Fig.12 , which shows a label device 120 provided by an embodiment of the present disclosure, the label device 120 includes: a receiving part 1201, a parsing part 1202, a first obtaining part 1203, a compensation part 1204 and a second obtaining part 1205; wherein,

[0137] The receiving part 1201 is configured to receive a ranging message sent by a positioning base station and record a receiving timestamp of the ranging message, wherein the positioning base station includes a primary base station and at least three secondary base stations within its coverage area;

[0138] The parsing part 1202 is configured to parse the ranging message to obtain the fixed coordinate information of the master base station and the slave base station, the sending and receiving time difference information of the ranging message, and the clock compensation coefficient;

[0139] The first obtaining part 1203 is configured to obtain a preliminary arrival time difference according to the receiving timestamp and the sending and receiving time difference information of the ranging message;

[0140] The compensation part 1204 is configured to perform clock drift compensation on the preliminary arrival time difference according to the time reference of the primary base station and the clock compensation coefficient to obtain a precise arrival time difference;

[0141] The second obtaining part 1205 is configured to obtain the positioning coordinates of the tag device itself according to the precise arrival time difference and the fixed coordinate information of the master base station and the slave base station.

[0142] Based on the same inventive concept as the above technical solution, see Fig.13 , which shows a main base station device 130 provided by an embodiment of the present disclosure, the main base station device 130 includes: a division part 1301, a ranging part 1302, an acquisition part 1303 and a first sending part 1304; wherein,

[0143] The dividing part 1301 is configured to send the divided timing information to the slave base station, so that the slave base station learns the corresponding ranging cycle and ranging time slot in the allocated ranging block;

[0144] The ranging part 1302 is configured to complete the interaction process of the ranging message with the secondary base station in the ranging cycle and the ranging time slot within a ranging period, and obtain the sending and receiving time difference information of the ranging message with the secondary base station;

[0145] The acquisition part 1303 is configured to acquire a clock compensation coefficient according to the sending and receiving time difference information of the ranging message;

[0146] The first sending part 1304 is configured to send the clock compensation coefficient to the tag device within the coverage of the main base station, so that the tag device performs clock drift compensation based on the clock compensation coefficient.

[0147] Based on the same inventive concept as the above technical solution, see Fig.14 , which shows a slave base station device 140 provided by an embodiment of the present disclosure, the slave base station device 140 includes: a learning part 1401, a recording part 1402 and a second sending part 1403; wherein,

[0148] The acquiring part 1401 is configured to receive timing information sent by the primary base station, and acquire the ranging cycle and ranging time slot for the ranging message interaction with the primary base station according to the timing information;

[0149] The recording part 1402 is configured to complete the interaction of ranging messages with the primary base station in the ranging cycle and ranging time slot within a ranging period, and record the sending and receiving time difference information of the ranging message;

[0150] The second sending part 1403 is configured to send its own fixed coordinate information, clock compensation coefficient and the sending and receiving time difference information of the ranging message to the tag device within its coverage range, so that the tag device obtains the arrival time difference.

[0151] It can be understood that the above-mentioned ranging part 1302 can be the UWB communication component 231 in the network node device 200 in the specific implementation process. This embodiment of the present disclosure will not be repeated. In addition, in this embodiment, "part" can be a part of the circuit, a part of the processor, a part of the program or software, etc., of course, it can also be a unit, a module, or a non-modular one.

[0152] In addition, each component in this embodiment may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above integrated unit may be implemented in the form of hardware or in the form of software function modules.

[0153] If the integrated unit is implemented in the form of a software function module and is not 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 this embodiment is essentially or the part that contributes to the prior art or the whole or part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, server, or network device, etc.) or a processor to perform all or part of the steps of the method described in this embodiment. The aforementioned storage medium includes: U disk, mobile hard disk, read only memory (ROM), random access memory (RAM), disk or optical disk, etc., various media that can store program codes.

[0154] Therefore, this embodiment provides a computer storage medium, which stores a positioning program based on UWB downlink arrival time difference. When the positioning program based on UWB downlink arrival time difference is executed by at least one processor, the steps of the positioning method based on UWB downlink arrival time difference described in the above technical solution are implemented.

[0155] It can be understood that the exemplary technical solutions of the tag device 120, the main base station device 130, and the slave base station device 140 are the same concept as the technical solution of the positioning method based on the UWB downlink arrival time difference. Therefore, the details of the technical solutions of the tag device 120, the main base station device 130, and the slave base station device 140 that are not described in detail can be found in the description of the technical solution of the positioning method based on the UWB downlink arrival time difference. This embodiment of the disclosure will not be elaborated on this.

[0156] It should be noted that the technical solutions described in the embodiments of the present disclosure can be combined arbitrarily without conflict.

[0157] The above is only a specific embodiment of the present disclosure, but the protection scope of the present disclosure is not limited thereto. Any person skilled in the art who is familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present disclosure, which should be included in the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be based on the protection scope of the claims.

Claims

1. A positioning method based on UWB downlink arrival time difference, characterized in that: The method is applied to a label device, and the method comprises: Receive a ranging message sent by a positioning base station, and record a receiving timestamp of the ranging message, wherein the positioning base station includes a primary base station and at least three secondary base stations within its coverage area; Parsing the ranging message to obtain fixed coordinate information of the master base station and the slave base station, time difference information of sending and receiving the ranging message, and a clock compensation coefficient; Obtaining a preliminary arrival time difference according to the receiving timestamp and the sending and receiving time difference information of the ranging message; According to the time reference of the primary base station and the clock compensation coefficient, clock drift compensation is performed on the preliminary arrival time difference to obtain an accurate arrival time difference; Obtaining the positioning coordinates of the tag device itself according to the precise arrival time difference and the fixed coordinate information of the master base station and the slave base station; The obtaining of the preliminary arrival time difference according to the receiving timestamp and the sending and receiving time difference information of the ranging message includes: Obtaining a preliminary time difference value of the tag device itself according to the recorded receiving timestamp of the ranging message received by the tag device itself; Obtaining a preliminary time difference value between the master base station and the slave base station according to the time difference information of sending and receiving the ranging message obtained by parsing; Obtaining a preliminary arrival time difference according to the preliminary time difference value of the tag device itself and the preliminary time difference values ​​of the master base station and the slave base station; The performing clock drift compensation on the preliminary arrival time difference according to the time reference of the primary base station and the clock compensation coefficient to obtain a precise arrival time difference comprises: Obtain the clock drift of the slave base station and the tag device according to the acquired time difference information of sending and receiving the ranging messages of the master base station and the slave base station and the receiving timestamp of the ranging message recorded by the tag device; The clock drift is compensated according to the clock compensation coefficient to obtain an accurate arrival time difference.

2. The method according to claim 1, characterized in that The receiving a ranging message sent by a positioning base station and recording a receiving timestamp of the ranging message includes: In a ranging cycle, receiving a Poll message and a Final message sent by a master base station among the positioning base stations; In a ranging cycle, receiving a Response message sent from the base station; The receiving timestamps of the received Poll message, Final message and Response message are recorded.

3. The method according to claim 1, characterized in that The parsing of the ranging message to obtain the fixed coordinate information of the master base station and the slave base station, the sending and receiving time difference information of the ranging message, and the clock compensation coefficient includes: Parsing the Poll message sent by the primary base station to obtain the fixed coordinate information of the primary base station, the sending and receiving time difference information of the ranging message, and the clock compensation coefficient; The Response message sent by the slave base station is parsed to obtain the fixed coordinate information of the slave base station, the sending and receiving time difference information of the ranging message, and the clock compensation coefficient.

4. A positioning method based on UWB downlink arrival time difference, characterized in that: The method is applied to a primary base station, and the method includes: Sending the divided timing information to the slave base station so that the slave base station acquires the corresponding ranging cycle and ranging time slot in the allocated ranging block; In a ranging cycle, the interaction process of the ranging message is completed with the slave base station in the ranging cycle and the ranging time slot, and the time difference information of sending and receiving the ranging message with the slave base station is obtained, wherein the time difference information of sending and receiving the ranging message with the slave base station is the time difference between the master base station receiving the Response Message of the slave base station and sending the FinalMessage; Obtain a clock compensation coefficient according to the time difference information of sending and receiving the ranging message, wherein the clock compensation coefficient of the master base station is the time difference between the master base station sending the Poll Message and sending the Final Message, and fill the value into the Poll Message; The clock compensation coefficient is sent to the tag device within the coverage of the main base station, so that the tag device performs clock drift compensation based on the clock compensation coefficient, wherein the tag device obtains the clock compensation coefficient of the main base station from the Poll Message and the time difference between the tag device receiving the Poll Message and receiving the Final Message to perform clock drift compensation.

5. A positioning method based on UWB downlink arrival time difference, characterized in that: The method is applied to a secondary base station, and the method comprises: receiving timing information sent by the primary base station, and obtaining, according to the timing information, a ranging cycle and a ranging time slot for interacting with the primary base station in a ranging message; In a ranging cycle, in the ranging cycle and the ranging time slot, the interaction of the ranging message with the primary base station is completed, and the sending and receiving time difference information of the ranging message is recorded, wherein the sending and receiving time difference information of the ranging message is the time difference between the secondary base station receiving the Poll Message of the primary base station and sending the Response Message; The fixed coordinate information, clock compensation coefficient and the time difference between sending and receiving the ranging message are sent to the tag device within its coverage range so that the tag device can obtain the arrival time difference, wherein the clock compensation coefficient of the slave base station is the time difference between the slave base station receiving the Poll Message of the master base station and sending the Response Message.

6. A labeling device, characterized in that: The label device comprises: a receiving part, a parsing part, a first obtaining part, a compensation part and a second obtaining part; wherein, The receiving part is configured to receive a ranging message sent by a positioning base station and record a receiving timestamp of the ranging message, wherein the positioning base station includes a primary base station and at least three secondary base stations within its coverage area; The parsing part is configured to parse the ranging message to obtain the fixed coordinate information of the master base station and the slave base station, the sending and receiving time difference information of the ranging message, and the clock compensation coefficient; The first obtaining part is configured to obtain a preliminary arrival time difference according to the receiving timestamp and the sending and receiving time difference information of the ranging message; The compensation part is configured to perform clock drift compensation on the preliminary arrival time difference according to the time reference of the primary base station and the clock compensation coefficient to obtain a precise arrival time difference; The second obtaining part is configured to obtain the positioning coordinates of the tag device itself according to the precise arrival time difference and the fixed coordinate information of the master base station and the slave base station; Wherein, the first obtaining part is configured as follows: Obtaining a preliminary time difference value of the tag device itself according to the recorded receiving timestamp of the ranging message received by the tag device itself; Obtaining a preliminary time difference value between the master base station and the slave base station according to the time difference information of sending and receiving the ranging message obtained by parsing; Obtaining a preliminary arrival time difference according to the preliminary time difference value of the tag device itself and the preliminary time difference values ​​of the master base station and the slave base station; The compensation part is configured as follows: Obtain the clock drift of the slave base station and the tag device according to the acquired time difference information of sending and receiving the ranging messages of the master base station and the slave base station and the receiving timestamp of the ranging message recorded by the tag device; The clock drift is compensated according to the clock compensation coefficient to obtain an accurate arrival time difference.

7. A master base station device, characterized in that: The main base station device includes: a division part, a ranging part, an acquisition part and a first sending part; wherein, The dividing part is configured to send the divided timing information to the slave base station, so that the slave base station learns the corresponding ranging cycle and ranging time slot in the allocated ranging block; The ranging part is configured to complete the interaction process of the ranging message with the slave base station in the ranging cycle and the ranging time slot within a ranging cycle, and obtain the sending and receiving time difference information of the ranging message with the slave base station, wherein the sending and receiving time difference information of the ranging message with the slave base station is the time difference between the master base station receiving the Response Message of the slave base station and sending the Final Message; The acquisition part is configured to acquire a clock compensation coefficient according to the time difference information of sending and receiving the ranging message, wherein the clock compensation coefficient of the primary base station is the time difference between the primary base station sending the Poll Message and sending the Final Message, and the value is filled in the Poll Message; The first sending part is configured to send the clock compensation coefficient to the tag device within the coverage of the main base station, so that the tag device performs clock drift compensation based on the clock compensation coefficient, wherein the tag device obtains the clock compensation coefficient of the main base station from the Poll Message and the ratio of the time difference between the tag device receiving the PollMessage and receiving the Final Message to perform clock drift compensation.

8. A slave base station device, characterized in that: The slave base station device includes: a learning part, a recording part and a second sending part; wherein, The acquiring part is configured to receive timing information sent by the primary base station, and acquire the ranging cycle and ranging time slot for the ranging message interaction with the primary base station according to the timing information; The recording part is configured to complete the interaction of ranging messages with the primary base station in the ranging cycle and the ranging time slot within a ranging period, and record the sending and receiving time difference information of the ranging message, wherein the sending and receiving time difference information of the ranging message is the time difference between the secondary base station receiving the Poll Message of the primary base station and sending the Response Message; The second sending part is configured to send its own fixed coordinate information, clock compensation coefficient and the time difference information of sending and receiving the ranging message to the tag device within its coverage range, so that the tag device obtains the arrival time difference, wherein the clock compensation coefficient of the slave base station is the time difference between the slave base station receiving the Poll Message of the master base station and sending the Response Message.

9. A positioning system based on UWB downlink arrival time difference, characterized in that: The positioning system includes: a main base station, one or more slave base stations and one or more tag devices; wherein, The one or more tag devices are configured to perform the steps of the positioning method based on UWB downlink arrival time difference according to any one of claims 1 to 3; The main base station is configured to perform the steps of the positioning method based on UWB downlink arrival time difference according to claim 4; The one or more slave base stations are configured to execute the steps of the positioning method based on UWB downlink arrival time difference as described in claim 5.

10. A computer storage medium, characterized in that: The computer storage medium stores a positioning program based on UWB downlink arrival time difference, and when the positioning program based on UWB downlink arrival time difference is executed by at least one processor, the steps of the positioning method based on UWB downlink arrival time difference are implemented as described in any one of claims 1 to 3 or claim 4 or claim 5.

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