Three-dimensional lightweight positioning method based on integrated UWB base station

Abstract

The application discloses a three-dimensional lightweight positioning method based on an integrated UWB base station, and the method comprises the following steps: quantitatively processing the spatial height to obtain a plurality of different spatial heights; establishing a three-dimensional spatial position model of a target tag corresponding to a certain spatial height and a UWB base station antenna array; determining the position coordinates of the target tag at each spatial height according to the three-dimensional spatial position model; and determining the first position of the target tag according to the position of the target tag at each spatial height. According to the application, high-precision positioning of the target tag can be realized.

Description

Technical Field

[0001] This invention relates to the field of spatial positioning, specifically to a lightweight three-dimensional positioning method and apparatus based on an integrated UWB base station. Background Technology

[0002] With the continuous advancement of technology, UWB (Ultra-Wideband) wireless positioning technology has become a hot topic and the preferred choice for future wireless positioning technologies due to its advantages such as low power consumption, good multipath resistance, high security, low system complexity, and especially its ability to provide very accurate positioning. Existing two-dimensional positioning systems mainly consist of at least 3-4 UWB receivers (i.e., UWB base stations) and UWB tags. Location determination is achieved by the UWB base stations receiving the UWB signals transmitted by the tags, filtering out various noise interferences during electromagnetic wave transmission to obtain signals containing valid information, and then analyzing the obtained valid data to obtain the coordinates of the location. Related basic positioning algorithms include TDOA (Time Difference of Arrival), AOA (Angle of Arrival), and TOF (Time of Flight). However, in practical applications, existing technical solutions require the deployment of at least 3-4 UWB base stations. Especially for three-dimensional positioning requirements, at least 5 UWB base stations need to be deployed on the roof and ground respectively to achieve three-dimensional positioning. On-site construction requires a lot of manpower and time, and the cost of the receiving base station itself is also high. Summary of the Invention

[0003] This invention provides a lightweight three-dimensional positioning method and device based on an integrated UWB base station to achieve high-precision positioning.

[0004] Therefore, the present invention provides the following technical solution:

[0005] A lightweight 3D positioning method based on an integrated UWB base station, the method comprising:

[0006] The spatial height is quantified to obtain multiple different spatial heights;

[0007] Establish a three-dimensional spatial position model of the target tag and the UWB base station antenna array corresponding to a certain spatial height;

[0008] Determine the position coordinates of the target label at each spatial height based on the three-dimensional spatial position model;

[0009] The position of the target label is determined based on the position of the target label at each spatial height.

[0010] Optionally, establishing a three-dimensional spatial position model of the target tag and the UWB base station antenna array corresponding to a certain spatial height includes:

[0011] In a two-dimensional plane, a positional model of each group of antennas in the antenna array is established based on the positions of the antennas in the antenna array.

[0012] Based on the positional relationship between different antennas in the antenna array, a distance model for each antenna corresponding to the target tag is established.

[0013] Optionally, the location model is: F(x,y,h,dis)=0, where x and y represent the horizontal coordinates of the target tag's location, h represents the spatial height, and dis represents the distance difference between the target tag and the two ends of a set of antennas.

[0014] Optionally, determining the position coordinates of the target label at each spatial height based on the three-dimensional spatial position model includes:

[0015] Obtain the distance difference between the target tag and two antennas in each group of antennas in the antenna array;

[0016] The relative position of the target tag with respect to the antenna array is determined based on the sign of the distance difference.

[0017] Based on the distance difference and the relative position, determine the relative coordinate information of each group of antennas corresponding to the target tag;

[0018] The relative coordinate information is transformed into a spatial coordinate system to obtain the position coordinates of the target label at the corresponding spatial height.

[0019] Optionally, determining the position of the target label based on its position at each spatial height includes:

[0020] Based on the position of the target tag at each spatial height, the distance difference between the target tag and two antennas in any group of antennas in the antenna array is calculated in reverse, and the phase difference of the electromagnetic waves of the two antennas is determined based on the distance difference.

[0021] The position of the target tag is determined by calculating the phase difference at each spatial height in reverse and measuring the phase difference of the electromagnetic waves from the two antennas.

[0022] A lightweight 3D positioning device based on an integrated UWB base station, the device comprising:

[0023] The spatial division module is used to quantify the spatial height and obtain multiple different spatial heights;

[0024] The model building module is used to build a three-dimensional spatial position model of the target tag and the UWB base station antenna array corresponding to a certain spatial height;

[0025] The positioning module is used to determine the position coordinates of the target label at each spatial height based on the three-dimensional spatial position model;

[0026] The location determination module is used to determine the location of the target label based on the position of the target label at each spatial height.

[0027] Optionally, the model building module includes:

[0028] The position model establishment unit is used to establish a position model of each group of antennas in the antenna array in a two-dimensional plane based on the position of the antennas in the antenna array;

[0029] The distance model building unit is used to build a distance model for each antenna corresponding to the target tag based on the positional relationship between different antennas in the antenna array.

[0030] Optionally, the location model is: F(x,y,h,dis)=0, where x and y represent the horizontal coordinates of the target tag's location, h represents the spatial height, and dis represents the distance difference between the target tag and the two ends of a set of antennas.

[0031] Optionally, the positioning module includes:

[0032] The distance difference acquisition unit is used to acquire the distance difference between the target tag and two antennas in each group of antennas in the antenna array;

[0033] A relative position determination unit is used to determine the relative position of the target tag relative to the antenna array based on the sign of the distance difference.

[0034] The relative coordinate determination unit is used to determine the relative coordinate information of each group of antennas corresponding to the target tag based on the value of the distance difference and the relative position.

[0035] The coordinate transformation unit is used to perform spatial coordinate system transformation on the relative coordinate information to obtain the position coordinates of the target label at the corresponding spatial height.

[0036] Optionally, the location determination module includes:

[0037] The phase difference calculation unit is used to calculate the distance difference between the target tag and two antennas in any group of antennas in the antenna array based on the position of the target tag at each spatial height, and to determine the phase difference of the electromagnetic waves of the two antennas based on the distance difference.

[0038] The location information determination unit is used to determine the location of the target tag based on the phase difference corresponding to each spatial height calculated in reverse and the phase difference of the electromagnetic waves of the two antennas measured.

[0039] The three-dimensional positioning method and apparatus based on an integrated UWB base station provided in this invention uses the integrated UWB base station as the sole signal receiving device, divides the three-dimensional space according to different horizontal heights, obtains the phase difference between the signals of two antennas in the antenna module at different heights through the antenna array, and performs corresponding calculations based on the relative relationship of the phase difference between each pair of antennas in the antenna array, thereby achieving high-precision three-dimensional positioning based on the integrated UWB base station. The positioning accuracy can reach the centimeter level in both horizontal and vertical dimensions within the effective positioning range. Attached Figure Description

[0040] Figure 1 This is a structural block diagram of the multi-antenna positioning subboard in the integrated UWB base station on which the method of this invention is based;

[0041] Figure 2 This is a flowchart of the three-dimensional lightweight positioning method based on an integrated UWB base station according to the present invention;

[0042] Figure 3 This is a flowchart illustrating the method of determining the position coordinates of the target label at each spatial height based on a three-dimensional spatial position model in this invention.

[0043] Figure 4 This is a structural schematic diagram of the three-dimensional lightweight positioning device based on an integrated UWB base station according to the present invention. Detailed Implementation

[0044] To enable those skilled in the art to better understand the embodiments of the present invention, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings and implementation methods.

[0045] To address the issue of the high labor and time costs associated with deploying multiple UWB base stations in existing technologies, this invention provides a three-dimensional positioning method and apparatus based on an integrated UWB base station. This method uses the integrated UWB base station as the sole signal receiving device, dividing the three-dimensional space into different horizontal levels, and then searching for the set of optimal location points at different height scales. By dividing the space layer by layer at different heights, multiple sets of optimal location points at different heights can be obtained. Then, based on the calculated location results, the difference between the theoretical value and the actual location point can be recalculated using the sampling values ​​from any set of antennas. Finally, this theoretical value is sorted with the experimental results obtained from the actual UWB receiver to obtain the final location coordinates.

[0046] It should be noted that the integrated UWB base station refers to a UWB base station with at least three multi-antenna positioning sub-boards. In other words, the antenna array of the integrated UWB base station in this invention has at least three antenna positioning sub-boards. Each antenna positioning sub-board includes a set of receiving antennas, and each set of receiving antennas has at least two receiving antennas.

[0047] like Figure 1 The diagram shown is a structural block diagram of a multi-antenna positioning sub-board in an integrated UWB base station upon which the method of this invention is based. Each multi-antenna positioning sub-board includes a UWB control module, and at least two positioning modules and receiving antennas respectively signal-connected to the UWB control module. Figure 1 The diagram shows two UWB positioning modules and receiving antennas: a first UWB positioning module and a second UWB positioning module connected to the UWB control module; a first receiving antenna connected to the first UWB positioning module; and a second receiving antenna connected to the second UWB positioning module. Each pair of independent UWB positioning modules receives signals transmitted by the target tag, which are used by the corresponding single multi-antenna positioning sub-board to calculate the phase difference.

[0048] The lightweight three-dimensional positioning method and apparatus based on an integrated UWB base station provided in this invention achieves high-precision three-dimensional positioning of target tags by using the integrated UWB base station as the sole signal receiving device. The advantages of the integrated UWB base station are:

[0049] 1) Low cost: The positioning network of multiple distributed UWB base stations is centralized into a single UWB base station, which reduces its costs in terms of hardware, construction and management.

[0050] 2) Low power consumption: The integrated UWB base station adopts phase difference processing logic (i.e., PDOA, Phase-Difference-of-Arrival), which significantly improves the high power consumption caused by frequent ranging of the located tag compared with the existing TOF+AOA single base station.

[0051] For ease of description, the following embodiments use two receiving antennas in each group of receiving antennas as an example. Each group of receiving antennas can also be called an antenna module.

[0052] Reference Figure 2 , Figure 2 This is a flowchart of the three-dimensional lightweight positioning method based on an integrated UWB base station according to the present invention, which includes the following steps:

[0053] In step 201, the spatial height is quantized to obtain multiple different spatial heights.

[0054] In practical applications, the granularity of quantization can be set according to the accuracy requirements of positioning, and this embodiment of the invention does not limit this.

[0055] In step 202, a three-dimensional spatial position model of the target tag and the UWB base station antenna array corresponding to a certain spatial height is established.

[0056] Specifically, in a two-dimensional plane, a positional model of each group of antennas in the antenna array is established based on the positions of the antennas in the antenna array. Then, based on the positional relationships between different antennas in the antenna array, a distance model between the target tag and each group of antennas is established.

[0057] The position model of each antenna group can be represented as:

[0058] F(x,y,h,dis)=0(1)

[0059] Where x and y represent the horizontal coordinates of the target tag's position, h represents the spatial height, and dis represents the distance difference between the target tag and the two ends of a set of antennas.

[0060] For each group of antennas, there is a unique set of formulas (1) corresponding to it.

[0061] The distance model between the target tag and each group of antennas can be represented as:

[0062] G(x i y i ,x j ,y j )=0(2)

[0063] Where x and y represent the horizontal coordinates of the target tag's position, and i and j represent two different antennas in a set of antennas.

[0064] Based on formulas (1) and (2) above, the relative position information of the target tag under different antenna arrays can be obtained. Specifically, according to formula (1), a set of high-dimensional nonlinear equations relating to the position coordinates of the target tag can be established for each antenna in the antenna array. Then, formula (2) is used to establish the relationship between the position coordinates of the target tag between different antennas. In this way, by solving the set of nonlinear equations, the position coordinate information of the target tag can be obtained.

[0065] In step 203, the position coordinates of the target label at each spatial height are determined according to the three-dimensional spatial position model.

[0066] The specific process is as follows: Figure 3 As shown, it includes the following steps:

[0067] Step 301: Obtain the distance difference between the target tag and two antennas in each group of antennas in the antenna array.

[0068] In a UWB antenna array, each antenna in each group is equivalent to a radio transmitter. A receiving device can obtain the phase difference between the electromagnetic waves arriving at the target tag from different transmitters. That is, by receiving the electromagnetic waves from two antennas in each group of the UWB base station array antennas, determining the phase difference between the two electromagnetic waves, and then calculating the distance difference between the target tag and the two antennas based on this phase difference.

[0069] Based on the principles of optics and electromagnetism, the distance difference diff between the target tag and the two antennas can be calculated using the following formula:

[0070]

[0071] Where p represents the phase difference, 360 represents one period of a phase, c represents the speed of light 3.0*10^8 m / s, and fc represents the electromagnetic wave frequency. For example, the FCC allows UWB devices in the United States to use a frequency bandwidth of 3.1 GHz to 10.6 GHz; the European Commission's decision has divided the UWB spectrum into 3.4 GHz-4.8 GHz and 6 GHz-8.5 GHz.

[0072] By calculating the distance difference, the original positioning problem using a UWB receiver can be transformed into a spatial geometry problem in high-dimensional space where the distance difference between two locations equals a certain value. Based on the mathematical theory of hyperboloids, it can be concluded that the set of all points satisfying this condition (i.e., the distance difference between two locations equals a certain value) is a spatial hyperboloid conic surface.

[0073] It should be noted that the distance difference obtained from the above conversion results can also be reflected by the phase difference, because the above calculation only affects the quantization scale and does not affect the positive or negative value of the result.

[0074] Furthermore, by combining actual scenario analysis, the location of the target tag on the hyperbolic conical surface can be determined based on the distance from the target tag to each antenna in each group of antennas in the antenna array, thereby reducing the number of calculations and improving computational efficiency.

[0075] Accordingly, in step 302, the relative position of the target tag with respect to the antenna array is determined based on the positive or negative value of the distance difference.

[0076] Step 303: Determine the relative coordinate information of each group of antennas corresponding to the target tag based on the distance difference value and the relative position.

[0077] Experiments revealed that the phase difference acquired by the target tag exhibits varying degrees of asymmetry at different distances from the antenna array. Therefore, to more accurately describe spatial location information, phase differences exceeding a certain threshold can be appropriately scaled, i.e., normalized calculations ensure the reasonableness of the phase difference values. The processed phase difference data is then transformed to reflect the spatial location transitions as closely as possible, thus better describing its spatial state and ultimately establishing a one-to-one correspondence between the phase difference value and its spatial location.

[0078] It should be noted that, in order to simplify the representation of relative coordinate information in the intermediate process, an independent coordinate system can be established for each group of antennas. Accordingly, the relative coordinate information of the target label for each group of antennas is also a coordinate in its respective antenna coordinate system, which is a two-dimensional coordinate.

[0079] Step 304: Perform a spatial coordinate system transformation on the relative coordinate information to obtain the position coordinates of the target label at the corresponding spatial height.

[0080] Since the relative coordinate information of the target tag corresponding to each group of antennas obtained in step 303 is in the coordinate system of its respective antenna, it is also necessary to determine the coordinates of the target tag in the global coordinate system based on these coordinates. Specifically, the corresponding two-dimensional spatial coordinate system can be translated and rotated according to the position and placement angle of the antenna to obtain the final position coordinates, which are the actual position of the target tag at the spatial height.

[0081] Continue to refer to Figure 2 In step 204, the position of the target label is determined based on the position of the target label at each spatial height.

[0082] Specifically, based on the position of the target tag at each spatial height, the distance difference between the target tag and any two antennas in a group of antennas in the antenna array can be calculated in reverse. The phase difference of the electromagnetic waves from the two antennas is then determined based on this distance difference. The position of the target tag is then determined by comparing the calculated phase difference for each spatial height with the measured phase difference of the electromagnetic waves from the two antennas. For example, for each spatial height, the difference between the calculated phase difference and the measured phase difference is calculated. The position of the target tag corresponding to the calculated result with the smallest difference (i.e., the three-dimensional positioning coordinates of the target tag) is selected as the position of the target tag, i.e., the positioning result of the target tag.

[0083] The three-dimensional positioning method based on an integrated UWB base station provided in this invention uses the integrated UWB base station as the sole signal receiving device, divides the three-dimensional space according to different horizontal heights, obtains the phase difference between the signals of two antennas in the antenna module at different heights through the antenna array, and performs corresponding calculations based on the relative relationship of the phase difference between each pair of antennas in the antenna array, thereby achieving high-precision three-dimensional positioning based on the integrated UWB base station.

[0084] Accordingly, embodiments of the present invention also provide a lightweight three-dimensional positioning device based on an integrated UWB base station, such as... Figure 4 The diagram shown is a structural schematic of the device.

[0085] In this embodiment, the positioning device includes the following modules:

[0086] The space division module 401 is used to quantify the space height to obtain multiple different space heights;

[0087] The model building module 402 is used to build a three-dimensional spatial position model of the target tag and the UWB base station antenna array corresponding to a certain spatial height;

[0088] The positioning module 403 is used to determine the position coordinates of the target label at each spatial height based on the three-dimensional spatial position model;

[0089] The position determination module 404 is used to determine the position of the target label based on the position of the target label at each spatial height.

[0090] One specific implementation structure of the above-mentioned model building module 402 may include the following units:

[0091] The position model establishment unit is used to establish a position model of each group of antennas in the antenna array in a two-dimensional plane based on the position of the antennas in the antenna array;

[0092] The distance model building unit is used to build a distance model for each antenna corresponding to the target tag based on the positional relationship between different antennas in the antenna array.

[0093] The specific expressions for the above-mentioned location model and distance model can be found in the descriptions in the previous embodiments of the present invention, and will not be repeated here.

[0094] One non-limiting embodiment of the positioning module 403 may include the following units:

[0095] The distance difference acquisition unit is used to acquire the distance difference between the target tag and two antennas in each group of antennas in the antenna array;

[0096] A relative position determination unit is used to determine the relative position of the target tag relative to the antenna array based on the sign of the distance difference.

[0097] The relative coordinate determination unit is used to determine the relative coordinate information of each group of antennas corresponding to the target tag based on the value of the distance difference and the relative position.

[0098] The coordinate transformation unit is used to perform spatial coordinate system transformation on the relative coordinate information to obtain the position coordinates of the target label at the corresponding spatial height.

[0099] One specific structure of the aforementioned position determination module 404 may include the following units:

[0100] The phase difference calculation unit is used to calculate the distance difference between the target tag and two antennas in any group of antennas in the antenna array based on the position of the target tag at each spatial height, and to determine the phase difference of the electromagnetic waves of the two antennas based on the distance difference.

[0101] The location information determination unit is used to determine the location of the target tag based on the phase difference corresponding to each spatial height calculated in reverse and the phase difference of the electromagnetic waves of the two antennas measured.

[0102] The working principle and operation mode of the three-dimensional lightweight positioning device based on the integrated UWB base station of the present invention can be referred to the relevant description in the previous embodiments of the present invention, and will not be repeated here.

[0103] The three-dimensional lightweight positioning device based on an integrated UWB base station provided in this embodiment of the invention uses the integrated UWB base station as the sole signal receiving device, divides the three-dimensional space according to different horizontal heights, obtains the phase difference value of the signals of two antennas in the antenna module at different heights through the antenna array, and performs corresponding calculations based on the relative relationship of the phase difference values ​​of each pair of antennas in the antenna array, thereby achieving high-precision three-dimensional positioning based on the integrated UWB base station.

[0104] It should be noted that the terms "comprising" and "having" and any variations thereof in the specification, claims and accompanying drawings of this invention are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such processes, methods, products or devices.

[0105] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to interchangeably. Each embodiment focuses on its differences from other embodiments. Furthermore, the system embodiments described above are merely illustrative. The modules and units described as separate components may or may not be physically separate; that is, they may be located on a single network unit or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0106] The embodiments of the present invention have been described in detail above. Specific implementation methods have been used to illustrate the present invention. The descriptions of the embodiments above are merely for the purpose of helping to understand the method and apparatus of the present invention, and are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention, and the content of this specification should not be construed as a limitation of the present invention. Therefore, any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A lightweight three-dimensional positioning method based on an integrated UWB base station, characterized in that, The method includes: The spatial height is quantified to obtain multiple different spatial heights; Establish a three-dimensional spatial position model of the target tag and the UWB base station antenna array corresponding to a certain spatial height; Determine the position coordinates of the target label at each spatial height based on the three-dimensional spatial position model; The position of the target label is determined based on the position of the target label at each spatial height; Determining the position coordinates of the target label at each spatial height based on the three-dimensional spatial position model includes: Obtain the distance difference between the target tag and two antennas in each group of antennas in the antenna array; The relative position of the target tag with respect to the antenna array is determined based on the sign of the distance difference. Based on the distance difference and the relative position, determine the relative coordinate information of each group of antennas corresponding to the target tag; The relative coordinate information is transformed into a spatial coordinate system to obtain the position coordinates of the target label at the corresponding spatial height; Determining the position of the target label based on its position at each spatial height includes: Based on the position of the target tag at each spatial height, the distance difference between the target tag and two antennas in any group of antennas in the antenna array is calculated in reverse, and the phase difference of the electromagnetic waves of the two antennas is determined based on the distance difference. The position of the target tag is determined by calculating the phase difference at each spatial height in reverse and measuring the phase difference of the electromagnetic waves from the two antennas.

2. The method according to claim 1, characterized in that, The establishment of a three-dimensional spatial position model of the target tag and the UWB base station antenna array corresponding to a certain spatial height includes: In a two-dimensional plane, a positional model of each group of antennas in the antenna array is established based on the positions of the antennas in the antenna array. Based on the positional relationship between different antennas in the antenna array, a distance model for each antenna corresponding to the target tag is established.

3. The method according to claim 2, characterized in that, The location model is as follows: Where x and y represent the horizontal coordinates of the target tag's position, h represents the spatial height, and dis represents the distance difference between the target tag and the two ends of a set of antennas.

4. A lightweight three-dimensional positioning device based on an integrated UWB base station, characterized in that, The device includes: The spatial division module is used to quantify the spatial height and obtain multiple different spatial heights; The model building module is used to build a three-dimensional spatial position model of the target tag and the UWB base station antenna array corresponding to a certain spatial height; The positioning module is used to determine the position coordinates of the target label at each spatial height based on the three-dimensional spatial position model; A location determination module is used to determine the location of the target label based on the position of the target label at each spatial height. The positioning module includes: The distance difference acquisition unit is used to acquire the distance difference between the target tag and two antennas in each group of antennas in the antenna array; A relative position determination unit is used to determine the relative position of the target tag relative to the antenna array based on the sign of the distance difference. The relative coordinate determination unit is used to determine the relative coordinate information of each group of antennas corresponding to the target tag based on the value of the distance difference and the relative position. The coordinate transformation unit is used to perform spatial coordinate system transformation on the relative coordinate information to obtain the position coordinates of the target label at the corresponding spatial height. The location determination module includes: The phase difference calculation unit is used to calculate the distance difference between the target tag and two antennas in any group of antennas in the antenna array based on the position of the target tag at each spatial height, and to determine the phase difference of the electromagnetic waves of the two antennas based on the distance difference. The location information determination unit is used to determine the location of the target tag based on the phase difference corresponding to each spatial height calculated in reverse and the phase difference of the electromagnetic waves of the two antennas measured.

5. The apparatus according to claim 4, characterized in that, The model building module includes: The position model establishment unit is used to establish a position model of each group of antennas in the antenna array in a two-dimensional plane based on the position of the antennas in the antenna array; The distance model building unit is used to build a distance model for each antenna corresponding to the target tag based on the positional relationship between different antennas in the antenna array.

6. The apparatus according to claim 5, characterized in that, The location model is as follows: Where x and y represent the horizontal coordinates of the target tag's position, h represents the spatial height, and dis represents the distance difference between the target tag and the two ends of a set of antennas.

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