TDOA positioning system, method and processor without clock synchronization

Abstract

Disclosed in the present invention are a TDOA positioning system, method and processor without clock synchronization. The system comprises: several UWB anchor points, which are arranged at any fixed positions within a signal coverage range; a fixed beacon, which periodically broadcasts first beacon information; a tag to be subjected to measurement, which periodically broadcasts second beacon information; and a background server, in which position coordinates of the UWB anchor points, position coordinates of the fixed beacon and the duration of flight from each UWB anchor point to the fixed beacon are preset, wherein each UWB anchor point receives, in real time, a first moment of arrival of the first beacon information and a second moment of arrival of the second beacon information, and the background server calculates a distance difference between said tag and each UWB anchor point on the basis of a duration between the first moment of arrival and the second moment of arrival and the duration of flight from each UWB anchor point to the fixed beacon, and calculates a real-time coordinate position of said tag on the basis of the distance difference and by using a hyperbolic equation. The present invention can reduce operation requirements while meeting the precision of a TDOA positioning process without clock synchronization.

Description

A TDOA positioning system, method and positioning processor without clock synchronization Technical Field

[0001] The present invention relates to the technical field of ultra-wideband communication indoor positioning, in particular to a method for

[0002] TDOA positioning system, method and positioning processor. Background Art

[0003] Today, UWB (ultra-wideband communication) indoor positioning technology is increasingly being used in intelligent industrial and mining enterprises, commerce, transportation, communities and other fields. Due to its technical particularity, TDOA (time difference of arrival) positioning method has become an effective method in UWB indoor positioning technology.

[0004] TDOA positioning is used in UWB indoor positioning solutions. The prerequisite is to measure the time difference between the arrival of the tag's beacon signal at each anchor point. To calculate this time difference, the two measured arrival times must be in the same time domain. This means that the clocks at each anchor point must be synchronized, and the time difference must be calculated on the same timeline. This is the only way to truly measure the time difference between the tag signal's arrival at each anchor point.

[0005] Currently, the common way to solve the clock synchronization between anchor points in the TDOA positioning method is to set a time base within the system and transmit it to each UWB anchor device with a timestamp. Each anchor point then uploads the reception time of the reference beacon with the timestamp to the positioning server. The positioning server calculates the time deviation between the anchor point and the time base station through these two timestamps, compensates it, and then sends it back to the anchor point. This ensures that each UWB anchor device is in the same clock system after compensation, achieving nanosecond-level clock synchronization.

[0006] However, this synchronization method suffers from complex algorithms and logic, requiring frequent switching and coordinated operations between receiving and transmitting modes. This requires the UWB anchor device to constantly exchange clock information with the backend processor to maintain synchronization. This synchronization method results in excessive communication channel usage by the UWB anchor device, placing a burden on the system and driving up costs.

[0007] Another approach to clock synchronization involves strictly geometrically symmetrically arranging the physical locations of UWB anchor devices, with a default time base equidistant from all anchors. This synchronization approach is challenging to implement, and in practice, it's difficult to guarantee absolute geometric symmetry.

[0008] Therefore, there is a need for a TDOA positioning system that does not require clock synchronization, which simplifies the hardware complexity and software implementation difficulty, while reducing the computing power overhead of the background server positioning operation engine, alleviating the pressure on the server, and enabling real-time positioning operations of more tags to be achieved under the server with the same computing power.

[0009] Summary of the Invention

[0010] In order to solve the technical problem that existing positioning methods occupy too much communication channels, the present invention provides a TDOA positioning system, method and positioning processor that do not require clock synchronization. The specific technical solutions are as follows:

[0011] The present invention provides a TDOA positioning system that does not require clock synchronization, comprising:

[0012] Several UWB anchor points are set up at any fixed location within the signal coverage area to receive beacon signals;

[0013] A fixed beacon is set within the line of sight of the UWB anchor point and periodically broadcasts first beacon information;

[0014] The tag to be tested periodically broadcasts the second beacon information;

[0015] The backend server communicates with each UWB anchor point, presets the location coordinates of the UWB anchor point, the location coordinates of the fixed beacon, and the flight time from each UWB anchor point to the fixed beacon;

[0016] During the positioning process, each UWB anchor point receives the first arrival time of the first beacon information and the second arrival time of the second beacon information in real time. The background server calculates the distance difference between the tag to be tested and each UWB anchor point based on the duration between the first arrival time and the second arrival time, and the flight duration of each UWB anchor point to the fixed beacon, and uses the hyperbola equation to calculate the real-time coordinate position of the tag to be tested based on the distance difference.

[0017] The TDOA positioning system that does not require clock synchronization provided by the present invention does not need to introduce a system time domain and clock system while meeting the TDOA positioning accuracy that does not require clock synchronization. This eliminates the need to carry timestamps in UWB beacons, eliminates the need to deploy complex clock synchronization processes, and eliminates the need for additional hardware equipment improvements. The amount of data uploaded by each anchor point is small, which reduces the computing power overhead of the background server positioning operation engine, alleviates the pressure on the server, and enables real-time positioning operations of more tags to be realized concurrently on a server with the same computing power.

[0018] In some implementations, after receiving the first arrival time of the first beacon information in real time, the UWB anchor point uses the arrival time of the second beacon information received next time as the second arrival time.

[0019] In some embodiments, each UWB anchor point calculates a duration between a first arrival time and a second arrival time;

[0020] Each UWB anchor point sends the duration to the background server through the signal interface.

[0021] In some embodiments, the backend server calculates the duration difference corresponding to each UWB anchor point and the total duration of the flight duration, and corrects the duration difference according to the total duration;

[0022] The distance difference between the tag to be tested and each UWB anchor point is calculated based on the corrected time difference.

[0023] In some embodiments, the first beacon information and the second beacon information do not include a system timestamp.

[0024] The clock synchronization-free TDOA positioning system provided by the present invention does not transmit a timestamp in the beacon information, thereby avoiding the need for high-precision synchronization with the system clock in the timestamp calculation positioning solution and simplifying the logical operation level.

[0025] In some implementations, each UWB anchor point calculates the duration between the first arrival time and the second arrival time based on its own timestamp.

[0026] In some implementations, the UWB baseband signal interface is not provided in the background server.

[0027] In some embodiments, a unidirectional UWB baseband signal receiving port is provided within the UWB anchor point;

[0028] A unidirectional UWB baseband signal transmission port is set in both the fixed beacon and the tag to be tested.

[0029] In some embodiments, according to another aspect of the present invention, the present invention further provides a TDOA positioning method that does not require clock synchronization, which is applied to the above-mentioned TDOA positioning system that does not require clock synchronization, comprising the steps of:

[0030] Several UWB anchor points receive in real time the first beacon information and the second beacon information periodically broadcast by the fixed beacon and the tag to be tested;

[0031] Each UWB anchor point sends the first arrival time of the received first beacon information and the second arrival time of the received second beacon information to the backend server in real time;

[0032] The backend server calculates the distance difference between the tag to be tested and each UWB anchor point based on the time between the first arrival time and the second arrival time, the position coordinates of the UWB anchor point preset in the backend server, the position coordinates of the fixed beacon, and the flight time from each UWB anchor point to the fixed beacon;

[0033] The background server calculates the real-time coordinate position of the tag to be tested based on the distance difference using the hyperbola equation.

[0034] In some embodiments, according to another aspect of the present invention, the present invention further provides a TDOA positioning processor that does not require clock synchronization, which is applied to a TDOA positioning system that does not require clock synchronization and includes several UWB anchor points, fixed beacons, and tags to be measured.

[0035] Several UWB anchor points are set up at any fixed location within the signal coverage area to receive beacon signals;

[0036] A fixed beacon is set within the line of sight of the UWB anchor point and periodically broadcasts first beacon information;

[0037] The tag to be tested periodically broadcasts the second beacon information;

[0038] No clock synchronization is required. The TDOA positioning processor communicates with each UWB anchor point separately, presetting the position coordinates of the UWB anchor point, the position coordinates of the fixed beacon, and the flight time from each UWB anchor point to the fixed beacon.

[0039] During the positioning process, each UWB anchor point receives the first arrival time of the first beacon information and the second arrival time of the second beacon information in real time. The background server calculates the distance difference between the tag to be tested and each UWB anchor point based on the duration between the first arrival time and the second arrival time, and the flight duration of each UWB anchor point to the fixed beacon, and uses the hyperbola equation to calculate the real-time coordinate position of the tag to be tested based on the distance difference.

[0040] The technical effects of the TDOA positioning system, method, and positioning processor provided by the present invention that do not require clock synchronization are as follows:

[0041] When the TDOA positioning accuracy that does not require clock synchronization is met, there is no need to introduce the system time domain and clock system, so that the UWB beacon does not need to carry a timestamp, there is no need to deploy a complex clock synchronization process, and no additional hardware equipment improvements are required; the amount of data uploaded by each anchor point is small, which reduces the computing power overhead of the background server positioning operation engine, alleviates the pressure on the server, and enables real-time positioning operations of more tags to be realized concurrently under the server with the same computing power. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0043] FIG1 is an exemplary diagram of a TDOA positioning system that does not require clock synchronization according to the present invention;

[0044] FIG2 is an example diagram of broadcast beacon information in a TDOA positioning system that does not require clock synchronization according to the present invention;

[0045] FIG3 is another example diagram of broadcast beacon information in a TDOA positioning system that does not require clock synchronization according to the present invention;

[0046] FIG4 is a flow chart of a TDOA positioning method without clock synchronization according to the present invention.

[0047] Numbers in the figure: UWB anchor point-10, fixed beacon-20, tag to be tested-30 and background server-40. DETAILED DESCRIPTION

[0048] In the following description, specific details such as specific system structures and technologies are provided for illustration rather than limitation to facilitate a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application may be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to avoid obstructing the description of the present application with unnecessary details.

[0049] It will be understood that when used in this specification and the appended claims, the term "comprising" indicates the presence of the described features, integers, steps, operations, elements and / or components, but does not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or collections.

[0050] To simplify the drawings, only the parts relevant to the present invention are schematically depicted in each figure; they do not represent the actual structure of the product. Furthermore, to simplify the drawings and facilitate understanding, in some figures, only one component with the same structure or function is schematically depicted or labeled. As used herein, "one" refers not only to "only one" but also to "more than one."

[0051] It should be further understood that the term "and / or" used in this specification and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.

[0052] In addition, in the description of the present application, the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0053] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the specific embodiments of the present invention will be described below with reference to the accompanying drawings. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings and other embodiments can be obtained based on these drawings without inventive work.

[0054] The principle of the TDOA positioning method, which does not require clock synchronization, is to measure the time difference between the signal emitted by the measured tag and the arrival of each base station anchor point. This time difference is multiplied by the speed of light to calculate the distance difference Delta between the tag and each anchor point. After measuring the distance difference Delta, the mathematical equation of the hyperbola is used. Using two fixed, known anchor points as the foci of the hyperbola, any point on the hyperbola satisfies the distance difference Delta from the two foci. Three anchor points are required in a 2D plane. The distance differences between two sets of tags and the anchor points are measured in pairs, resulting in two sets of hyperbolas. The intersection of these two sets of hyperbolas is the tag's location. In 3D space, four anchor points are required. The distance differences between three sets of tags and the anchor points are measured in pairs, resulting in three sets of hyperbolic surfaces. The intersection of these three hyperbolic surfaces is the tag's location. Therefore, as long as the distance differences between the tag and each fixed anchor point are accurately measured, the hyperbola equation can be mathematically solved to determine the measured point's location.

[0055] The TDOA positioning method, which does not require clock synchronization, is applied to UWB indoor positioning solutions. The prerequisite task is to measure the time difference between the beacon emitted by the tag and the arrival of each anchor point. In order to accurately obtain the time difference, the two measured "arrival times" need to be placed in the same time domain, that is, the clocks of each anchor point need to be synchronized, and the time difference must be obtained on the same time line to truly measure the time difference between the tag signal arriving at each anchor point.

[0056] Currently, a common solution to clock synchronization between anchor points in the TDOA positioning method, which does not require clock synchronization, is to set a time base within the system and transmit it to each UWB anchor device with a timestamp. Each anchor then uploads the reception time of the reference beacon with the timestamp to the positioning server. The positioning server calculates the time deviation between the anchor point and the time base station using these two timestamps, compensates for it, and then returns it to the anchor point. This ensures that each UWB anchor device is in the same clock system after compensation, achieving nanosecond-level clock synchronization. The disadvantage of this synchronization method is that the algorithm logic of the anchor device is complex, and the receiving and transmitting modes frequently switch and operate in coordination. This requires the UWB anchor device to continuously exchange clock information with the background operation to maintain clock synchronization. This synchronization method causes UWB anchor devices to occupy too much of the communication channel, which burdens the system and invisibly increases costs.

[0057] Another approach to clock synchronization involves strictly geometrically symmetrically arranging the physical locations of UWB anchor devices, with a default time base equidistant from all anchors. This synchronization approach is challenging to implement, and ensuring absolute geometric symmetry is difficult in practice. Therefore, whether implementing clock synchronization in software or hardware, it can reduce the effectiveness or increase costs of the TDOA positioning process without clock synchronization.

[0058] One embodiment of the present invention, as shown in FIG1 , provides a TDOA positioning system that does not require clock synchronization. The technical solution is conceived mainly in that a clock synchronization solution is not required and the UWB anchor point position does not need to be precisely arranged. The TODA positioning system designed based on the requirements of the solution includes several UWB anchor points 10, fixed beacons 20, tags to be tested 30, and a background server 40. It mainly relies on the arrival time of the signal sent by the fixed beacon and the arrival time of the signal sent by the tag to be tested 30 received by each anchor point 10 to obtain the duration, calculate the distance difference, and use the hyperbola equation to accurately locate the position. Based on the implementation process of this solution, several UWB anchor points 10 can be set at any fixed position within the signal coverage range, and there is no need to require the physical position of the UWB anchor point 10 device to be arranged geometrically symmetrically to achieve clock synchronization; the fixed beacon 20 used in conjunction with the UWB anchor point 10 is set at any position within the line of sight of the UWB anchor point, and periodically broadcasts the first beacon information; and a background server 40 is set in the TDOA system, and the background server 40 communicates with each The UWB anchor points 10 are communicated with each other, and the position coordinates of the UWB anchor points 10, the position coordinates of the fixed beacon 20, and the flight time of each UWB anchor point 10 to the fixed beacon 20 are pre-stored; during the positioning process, each UWB anchor point 10 receives the first arrival time of the first beacon information and the second arrival time of the second beacon information in real time, and the background server 40 calculates the distance between the tag to be tested 30 and each UWB anchor point 10 according to the time between the first arrival time and the second arrival time, and the flight time of each UWB anchor point 10 to the fixed beacon 20, and calculates the real-time coordinate position of the tag to be tested 30 using the hyperbola equation based on the distance difference.

[0059] For example, after the fixed beacon 20 and the three UWB anchor points A, B, and C are installed, their position coordinates are fixed and known, that is, the distance from the fixed beacon 20 to each UWB anchor point 10 is fixed and known, which is converted into the flight time α from the fixed beacon 20 to each UWB anchor point 10. a , α b , α c , change α a , α b , α c Pre-installed in the background server 40.

[0060] 2 and 3, the fixed beacon 20 broadcasts the beacon at time S. After receiving the first beacon information, the three UWB anchor points A, B, and C each record the receiving time as: S a 、S b 、S c The tag 30 to be tested broadcasts the second beacon information at time T. After the three UWB anchor points A, B, and C receive the second beacon information, they each record the reception time as: T a 、T b 、T c ; According to the calculation, the reception time τ between any two beacons of the tag 30 to be tested and the three UWB anchor points A, B, and C is obtained. a =T a -S a , τ b =T b -S b , τ c =T c -S c , and τ a , τ b , τ c By uploading to the backend server 40; the backend server 40 receives τ a , τ b , τ c After and preset α a , α b , α c Merge and calculate the corrected duration: τ' a =τ a +α a 、τ' b =τ b +α b ,τ' b =τ b +α b .

[0061] The backend server 40 calculates the actual arrival time difference between each UWB anchor point 10 and the tag 30 to be tested: τ' a -τ' b ,τ' b -τ' c ,τ' c -τ' a ; Converted into the distance difference between the two:

[0062] L ab =(τ' a -τ' b )*c;

[0063] L bc =(τ' b -τ'c )*c;

[0064] The coordinates of the tag 30 to be tested are calculated using the hyperbola method, and the coordinates of the known UWB anchor points A, B, and C (x a ,y a )、(x b ,y b )、(x c ,y c ), and substitute it into the following equation to obtain the coordinates T(x,y) of the tag 30 to be tested:

[0065] The TDOA positioning system that does not require clock synchronization provided by this embodiment does not need to introduce a system time domain and clock system while meeting the TDOA positioning accuracy that does not require clock synchronization. This eliminates the need to carry timestamps in UWB beacons, eliminates the need to deploy complex clock synchronization processes, and eliminates the need for additional hardware equipment improvements. The amount of data uploaded by each anchor point is small, which reduces the computing power overhead of the background server positioning operation engine, alleviates the pressure on the server, and enables real-time positioning operations for more tags to be performed concurrently on a server with the same computing power.

[0066] In one embodiment, in order to avoid the confusion in the time difference calculation during the continuous beacon information transmission and reception process affecting the positioning accuracy of the scheme, the UWB anchor point 10 uses the arrival time of the second beacon information received next time as the second arrival time after receiving the first arrival time of the first beacon information in real time, further limiting the UWB anchor point to calculate the time difference of the arrival time.

[0067] In one embodiment, the process of calculating the duration between the first arrival time and the second arrival time is set to be executed by each UWB anchor point 10, and each UWB anchor point 10 sends the duration to the background server 40 by setting a signal interface. The signal interface may not limit the communication method, wherein the signal interface between the UWB anchor points 10 is only used to transmit the duration with the background server. The transmission between the UWB anchor point 10 and the background server is one-way, and there is no need to exchange data with each other. The UWB baseband signal transmission mode of the UWB anchor point 10 is only receive-only and not send-only.

[0068] In one embodiment, in order to avoid the need for high-precision synchronization with the system clock in the timestamp calculation positioning scheme and simplify the logical operation level, the first beacon information and the second beacon information do not contain a system timestamp, but only include a fixed tag ID, a tag ID to be tested and a data packet serial number.

[0069] The clock synchronization-free TDOA positioning system provided by the present invention does not transmit a timestamp in the beacon information, thereby avoiding the need for high-precision synchronization with the system clock in the timestamp calculation positioning solution and simplifying the logical operation level.

[0070] In one embodiment, each UWB anchor point 10 calculates the duration between the first arrival time and the second arrival time according to its own timestamp, further satisfying the realization of accurate calculation of the duration difference without the need for system clock synchronization.

[0071] In one embodiment, the background server 40 does not perform UWB signal transmission, and therefore no UWB baseband signal interface is provided in the background server 40 .

[0072] In one embodiment, a unidirectional UWB baseband signal receiving port is provided in the UWB anchor point 10 ; and a unidirectional UWB baseband signal transmitting port is provided in both the fixed beacon 20 and the tag to be tested 30 .

[0073] Among them, during the continuous signal transmission process, the signal data contains a serial number. The same serial number determines that the signals sent by the fixed beacon and the tag belong to the same group of signals. The fixed beacon broadcast period is 50ms, and the time difference is less than 50ms for a valid signal.

[0074] In one embodiment, as shown in FIG4 , according to another aspect of the present invention, the present invention further provides a TDOA positioning method that does not require clock synchronization, which is applied to the above-mentioned TDOA positioning system that does not require clock synchronization, comprising the steps of:

[0075] S100: Several UWB anchor points receive in real time the first beacon information and the second beacon information periodically broadcast by the fixed beacon and the tag to be tested.

[0076] S200 Each UWB anchor point sends the first arrival time of the received first beacon information and the second arrival time of the received second beacon information to the background server in real time.

[0077] The S300 backend server calculates the distance difference between the tag to be tested and each UWB anchor point based on the duration between the first arrival time and the second arrival time, the position coordinates of the UWB anchor point preset in the backend server, the position coordinates of the fixed beacon, and the flight time from each UWB anchor point to the fixed beacon.

[0078] The S400 backend server calculates the real-time coordinate position of the tag to be tested based on the distance difference using the hyperbola equation.

[0079] For example, after the fixed beacon 20 and the three UWB anchor points A, B, and C are installed, their position coordinates are fixed and known, that is, the distance from the fixed beacon 20 to each UWB anchor point 10 is fixed and known, which is converted into the flight time α from the fixed beacon 20 to each UWB anchor point 10.a , α b , α c , change α a , α b , α c Pre-installed in the background server 40.

[0080] 2 and 3, the fixed beacon 20 broadcasts the beacon at time S. After receiving the first beacon information, the three UWB anchor points A, B, and C each record the receiving time as: S a 、S b 、S c The tag 30 to be tested broadcasts the second beacon information at time T. After the three UWB anchor points A, B, and C receive the second beacon information, they each record the reception time as: T a 、T b 、T c ; According to the calculation, the reception time τ between any two beacons of the tag 30 to be tested and the three UWB anchor points A, B, and C is obtained. a =T a -S a , τ b =T b -S b , τ c =T c -S c , and τ a , τ b , τ c By uploading to the backend server 40; the backend server 40 receives τ a , τ b , τ c After and preset α a , α b , α c Merge and calculate the corrected duration: τ' a =τ a + α a 、τ' b =τ b +α b 、τ' b =τ b +α b .

[0081] The backend server 40 calculates the actual arrival time difference between each UWB anchor point 10 and the tag 30 to be tested: τ' a -τ' b 、τ' b -τ' c 、τ' c -τ' a ; Converted into the distance difference between the two:

[0082] L ab =(τ' a -τ' b )*c;

[0083] L bc =(τ' b -τ' c )*c;

[0084] The coordinates of the tag 30 to be tested are calculated using the hyperbola method, and the coordinates of the known UWB anchor points A, B, and C (x a ,y a )、(x b ,y b )、(x c ,y c ), and substitute it into the following equation to obtain the coordinates T(x,y) of the tag 30 to be tested:

[0085] The TDOA positioning method that does not require clock synchronization provided in this embodiment does not need to introduce a system time domain and clock system while meeting the TDOA positioning accuracy that does not require clock synchronization. This eliminates the need to carry timestamps in UWB beacons, eliminates the need to deploy complex clock synchronization processes, and eliminates the need for additional hardware equipment improvements. The amount of data uploaded by each anchor point is small, which reduces the computing power overhead of the background server positioning operation engine, alleviates the pressure on the server, and enables real-time positioning operations for more tags to be performed concurrently on a server with the same computing power.

[0086] In one embodiment, according to another aspect of the present invention, the present invention further provides a TDOA positioning processor that does not require clock synchronization, which is applied to a TDOA positioning system that does not require clock synchronization and includes several UWB anchor points, fixed beacons and a tag to be tested, wherein the several UWB anchor points are set at any fixed position within the signal coverage range to receive beacon signals; the fixed beacon is set within the line of sight of the UWB anchor point and periodically broadcasts first beacon information; the tag to be tested periodically broadcasts second beacon information; the TDOA positioning processor that does not require clock synchronization is communicated with each UWB anchor point respectively, and presets the position coordinates of the UWB anchor point, the position coordinates of the fixed beacon and the flight time from each UWB anchor point to the fixed beacon; during the positioning process, each UWB anchor point receives the first arrival time of the first beacon information and the second arrival time of the second beacon information in real time, and the background server calculates the distance difference between the tag to be tested and each UWB anchor point based on the time between the first arrival time and the second arrival time and the flight time from each UWB anchor point to the fixed beacon, and calculates the real-time coordinate position of the tag to be tested using a hyperbola equation based on the distance difference.

[0087] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant description of other embodiments.

[0088] Those skilled in the art will appreciate that the units and steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented with electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0089] In the embodiments provided in the present application, it should be understood that the disclosed TDOA positioning system, method, and positioning processor that do not require clock synchronization can be implemented in other ways. For example, the above-described embodiment of a TDOA positioning system, method, and positioning processor that do not require clock synchronization is merely illustrative. For example, the division of the modules or units is merely a logical function division. In actual implementation, there may be other division methods. For example, multiple units or modules may be combined or integrated into another system, or some features may be ignored or not executed. Another point is that the communication connections between each other shown or discussed may be through some interfaces, communication connections of devices or units, or integrated circuits, which may be electrical, mechanical, or other forms.

[0090] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0091] In addition, the functional units in the various embodiments of the present application may be integrated into a single processing unit, or each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0092] It should be noted that the above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A TDOA positioning system without clock synchronization, characterized in that: include: Several UWB anchor points are set at any fixed position within the signal coverage area to receive beacon signals; A fixed beacon is arranged within the line of sight of the UWB anchor point and periodically broadcasts first beacon information; The tag to be tested periodically broadcasts the second beacon information; The backend server is respectively connected to each of the UWB anchor points for communication, and presets the position coordinates of the UWB anchor point, the position coordinates of the fixed beacon, and the flight time from each of the UWB anchor points to the fixed beacon; During the positioning process, each of the UWB anchor points receives the first arrival time of the first beacon information and the second arrival time of the second beacon information in real time. The background server calculates the distance difference between the tag to be tested and each of the UWB anchor points based on the duration between the first arrival time and the second arrival time, and the flight duration from each of the UWB anchor points to the fixed beacon, and calculates the real-time coordinate position of the tag to be tested using a hyperbolic equation based on the distance difference.

2. A TDOA positioning system without clock synchronization according to claim 1, characterized in that: After receiving the first arrival time of the first beacon information in real time, the UWB anchor point uses the arrival time of the second beacon information received next time as the second arrival time.

3. The TDOA positioning system without clock synchronization according to claim 1, characterized in that: Each of the UWB anchor points calculates the duration between the first arrival time and the second arrival time; Each of the UWB anchor points sends the duration to the background server through a signal interface.

4. The TDOA positioning system without clock synchronization according to claim 1, characterized in that: The backend server calculates the sum of the duration corresponding to each of the UWB anchor points and the flight duration, and corrects the duration difference according to the sum of the durations; The distance difference between the tag to be tested and each of the UWB anchor points is calculated according to the corrected time difference.

5. A TDOA positioning system without clock synchronization according to any one of claims 1 to 4, characterized in that: The first beacon information and the second beacon information do not include a system timestamp.

6. The TDOA positioning system without clock synchronization according to claim 5, characterized in that: Each of the UWB anchor points calculates the duration between the first arrival time and the second arrival time according to its own timestamp.

7. A TDOA positioning system without clock synchronization according to any one of claims 1 to 4, characterized in that: The background server does not have a UWB baseband signal interface.

8. The TDOA positioning system without clock synchronization according to claim 1, characterized in that: A unidirectional UWB baseband signal receiving port is provided in the UWB anchor point; The fixed beacon and the tag to be tested are both provided with a unidirectional UWB baseband signal transmission port.

9. A TDOA positioning method without clock synchronization, characterized in that: The TDOA positioning system without clock synchronization applied to any one of claims 1 to 8 comprises the steps of: Several UWB anchor points receive in real time the first beacon information and the second beacon information periodically broadcast by the fixed beacon and the tag to be tested; Each of the UWB anchor points sends the first arrival time of the received first beacon information and the second arrival time of the received second beacon information to the background server in real time; The backend server calculates the distance difference between the tag to be tested and each of the UWB anchor points according to the duration between the first arrival time and the second arrival time, the position coordinates of the UWB anchor point preset in the backend server, the position coordinates of the fixed beacon, and the flight duration from each of the UWB anchor points to the fixed beacon; The background server calculates the real-time coordinate position of the tag to be tested using a hyperbolic equation according to the distance difference.

10. A TDOA positioning processor that does not require clock synchronization, characterized in that: Applied to TDOA positioning system without clock synchronization including several UWB anchor points, fixed beacons and tags to be tested. A plurality of said UWB anchor points are arranged at any fixed position within the signal coverage range, and are used to receive beacon signals; The fixed beacon is arranged within the line of sight of the UWB anchor point and periodically broadcasts first beacon information; The tag to be tested periodically broadcasts second beacon information; The TDOA positioning processor without clock synchronization is respectively connected to each of the UWB anchor points for communication, and presets the position coordinates of the UWB anchor point, the position coordinates of the fixed beacon, and the flight time from each of the UWB anchor points to the fixed beacon; During the positioning process, each of the UWB anchor points receives the first arrival time of the first beacon information and the second arrival time of the second beacon information in real time. The background server calculates the distance difference between the tag to be tested and each of the UWB anchor points based on the duration between the first arrival time and the second arrival time, and the flight duration from each of the UWB anchor points to the fixed beacon, and calculates the real-time coordinate position of the tag to be tested using a hyperbolic equation based on the distance difference.

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