A coordinate conversion method and system based on Beidou RTK and UWB

Abstract

This invention relates to a coordinate transformation method and system based on BeiDou RTK and UWB. It includes: a positioning system mode employing four base stations and one tag, with four UWB base stations arranged indoors to form a rectangle. A reference point Q is selected at the boundary between indoors and outdoors, i.e., on any side of the rectangle. Two reference points S1 and S2 are set outdoors, forming an isosceles triangle with point Q. The absolute coordinates of the two outdoor reference points are measured using BeiDou positioning, and the absolute distance between the two reference points and Q can also be measured, thus obtaining the absolute coordinates of point Q in the BeiDou coordinate system. Similarly, reference points are selected on the other three sides of the rectangle, and their absolute coordinates in the BeiDou coordinate system are obtained. Therefore, the absolute coordinates of each base station in the BeiDou coordinate system are measured using pairwise reference points. During indoor positioning, the coordinate transformation is achieved by combining the absolute coordinates of the base stations in the BeiDou coordinate system with the position coordinates measured in the UWB coordinate system, enabling seamless indoor-outdoor positioning and improving positioning accuracy.

Description

Technical Field

[0001] This invention relates to the field of navigation and positioning, and in particular to a coordinate transformation method and system based on BeiDou RTK and UWB. Background Technology

[0002] Currently, indoor-outdoor joint positioning technology has become a major focus in navigation and positioning technology. Outdoor positioning primarily utilizes BeiDou RTK technology, but indoors, satellite signals are weaker, making high-precision positioning difficult. Therefore, UWB positioning technology is generally used for indoor positioning. However, a single positioning technology is insufficient to meet people's needs, hence indoor-outdoor joint positioning remains a hot technology. Unifying the coordinates between indoor and outdoor positioning is crucial. This technology selects reference points, establishes the Euclidean distance formula equation, calculates the absolute position of the indoor base station in the BeiDou coordinate system, and thus determines the absolute position of the target in the BeiDou coordinate system during indoor positioning. Summary of the Invention

[0003] The purpose of this invention is to provide a coordinate transformation method and system based on BeiDou RTK and UWB, which can convert indoor positioning coordinates into absolute coordinates in the BeiDou coordinate system, and the target under test can be observed in real time through the host computer, forming an indoor and outdoor joint positioning system.

[0004] To achieve the above objectives, the technical solution of the present invention is: a coordinate transformation method based on BeiDou RTK and UWB, comprising:

[0005] Four UWB base stations are arranged in a rectangle indoors, and four reference points are selected at the boundary between indoors and outdoors, that is, on the four sides of the rectangle.

[0006] Obtain the absolute coordinates of all selected reference points in the BeiDou coordinate system, and then calculate the absolute coordinates of the four UWB base stations in the BeiDou coordinate system by combining the coordinates of the reference points in pairs.

[0007] When performing indoor positioning, the position coordinates of the tag to be measured by the UWB base station indoors can be combined with the absolute coordinates of the UWB base station in the BeiDou coordinate system to convert the position coordinates of the tag to be measured indoors into BeiDou coordinates.

[0008] In one embodiment of the present invention, any reference point is obtained as follows:

[0009] Let Q be the reference point selected on one side of the rectangle. At the same time, two reference points S1 and S2 are selected outdoors. The two reference points S1 and S2 and the reference point Q form an isosceles triangle.

[0010] The absolute coordinates of two reference points S1 and S2 in the BeiDou coordinate system are measured by the BeiDou static solution algorithm, and the physical distance between reference point Q and the two reference points S1 and S2 is measured by physical measurement. The absolute coordinates of reference point Q in the BeiDou coordinate system are then calculated.

[0011] In one embodiment of the present invention, the UWB base station measures the location coordinates of the tag to be measured indoors as follows:

[0012] By deploying four UWB base stations indoors and using the UWB ranging algorithm, the coordinates of the tag under test in the UWB coordinate system, i.e., its location coordinates, are measured when the tag is indoors.

[0013] In one embodiment of the present invention, the absolute coordinates of two reference points S1 and S2 in the BeiDou coordinate system are measured by the BeiDou static solution algorithm, and the physical distance between reference point Q and the two reference points S1 and S2 is measured by physical measurement. The specific calculation formula for the absolute coordinates of reference point Q in the BeiDou coordinate system is as follows:

[0014]

[0015] The absolute coordinates of reference point Q in the BeiDou coordinate system are (x, y, z), and the absolute coordinates of the two reference points S1 and S2 in the BeiDou coordinate system are (x1, y1, z1) and (x2, y2, z2) respectively. The physical distances between reference point Q and the two reference points S1 and S2 are d1 and d2 respectively.

[0016] In one embodiment of the present invention, when performing indoor positioning, there is no need to customize the coordinates of the UWB base station. Instead, the coordinates of the UWB base station are directly set to the absolute coordinates of the UWB base station in the BeiDou coordinate system, so as to directly output the absolute coordinates of the tag under test in the BeiDou coordinate system, i.e., the BeiDou coordinates.

[0017] This invention also provides a coordinate transformation system based on BeiDou RTK and UWB, including a UWB base station, a tag under test, and a host computer;

[0018] The UWB base station is used to receive and transmit pulse signals from the tag under test and convert them into location coordinate information;

[0019] The tag under test has the same structure as the UWB base station and serves as the target under test, used to send and receive pulse signals from the UWB base station.

[0020] The host computer is connected to one of the UWB base stations via USB, and the host computer software can observe the position coordinates and movement trajectory of the tag under test in real time.

[0021] In one embodiment of the present invention, there are four UWB base stations arranged in a rectangular pattern indoors.

[0022] In one embodiment of the present invention, the host computer carries a program that executes the method steps described above.

[0023] Compared to existing technologies, this invention has the following advantages: By establishing an indoor base station and setting up an outdoor reference point, the absolute coordinates of the reference point in the BeiDou coordinate system are determined, thereby calculating the absolute coordinates of the base station in the BeiDou coordinate system. Then, in conjunction with a host computer, the absolute coordinates of each base station in the BeiDou coordinate system are set, and UWB indoor ranging is directly performed. The measured location information is the absolute coordinates in the BeiDou coordinate system, eliminating the need to customize the coordinates of the UWB base station indoors and saving a complex conversion process. Attached Figure Description

[0024] Figure 1 This is a flowchart illustrating a coordinate transformation method based on BeiDou RTK and UWB provided in Embodiment 1 of the present invention.

[0025] Figure 2 This is a schematic diagram of a coordinate transformation method based on BeiDou RTK and UWB provided in Embodiment 1 of the present invention.

[0026] Figure 3 This is a schematic diagram of a coordinate transformation system based on BeiDou RTK and UWB provided in Embodiment 2 of the present invention. Detailed Implementation

[0027] To make the technical problems solved by the present invention, the technical solutions adopted, and the technical effects achieved clearer, the technical solutions of the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0028] This invention provides a coordinate transformation method based on BeiDou RTK and UWB, comprising:

[0029] Four UWB base stations are arranged in a rectangle indoors, and four reference points are selected at the boundary between indoors and outdoors, that is, on the four sides of the rectangle.

[0030] Obtain the absolute coordinates of all selected reference points in the BeiDou coordinate system, and then calculate the absolute coordinates of the four UWB base stations in the BeiDou coordinate system by combining the coordinates of the reference points in pairs.

[0031] When performing indoor positioning, the position coordinates of the tag to be measured by the UWB base station indoors can be combined with the absolute coordinates of the UWB base station in the BeiDou coordinate system to convert the position coordinates of the tag to be measured indoors into BeiDou coordinates.

[0032] This invention also provides a coordinate transformation system based on BeiDou RTK and UWB, including a UWB base station, a tag under test, and a host computer;

[0033] The UWB base station is used to receive and transmit pulse signals from the tag under test and convert them into location coordinate information;

[0034] The tag under test has the same structure as the UWB base station and serves as the target under test, used to send and receive pulse signals from the UWB base station.

[0035] The host computer is connected to one of the UWB base stations via USB, and the host computer software can observe the position coordinates and movement trajectory of the tag under test in real time.

[0036] The following are specific implementation examples of the present invention.

[0037] Example 1:

[0038] This invention provides a coordinate transformation method based on BeiDou RTK and UWB, so that the coordinates measured by indoor UWB base stations are the absolute coordinates in the BeiDou coordinate system, eliminating the need to customize base station coordinate information and saving the transformation process.

[0039] Figure 1 This is a flowchart illustrating the coordinate transformation method based on BeiDou RTK and UWB provided in Embodiment 1 of the present invention.

[0040] like Figure 1 As shown, the method includes:

[0041] A1, four positioning base stations are placed in the four corners of the room in a rectangular shape.

[0042] A2. Set reference points on the rectangular boundary and outdoors, and calculate the absolute coordinates of the reference points.

[0043] Set a first reference point at the rectangular boundary and two second reference points outdoors.

[0044] Preferably, the BeiDou coordinates of the second reference point are obtained through a satellite static solution algorithm. For example, BeiDou RTK (Real-time kinematic) carrier phase differential technology can be used. This technology can be used to measure the absolute coordinates of the second reference point.

[0045] Preferably, since the first reference point is indoors, its coordinates cannot be measured using BeiDou technology. However, its physical distance to the two second reference points can be measured. Therefore, the absolute position coordinates of the first reference point can be calculated by establishing the Euclidean distance equation. The calculation formula is as follows:

[0046]

[0047] In the formula, the coordinates of the first reference point Q are (x, y, z), the coordinates of the second reference points S1 and S2 are (x1, y1, z1) and (x2, y2, z2) respectively, and the physical distances between the first reference point and the second reference point are d1 and d2.

[0048] A3, following the method in A2, sets a first reference point on each side of the rectangle and two second reference points outdoors. This allows us to obtain the coordinates of the first reference point on each side of the rectangle. Since the layout is rectangular, each base station is adjacent to two first reference points. Based on this, we can again establish Euclidean equations to calculate the absolute coordinates of each base station. The specific calculation formula is as follows:

[0049]

[0050] In the formula, the coordinates of base station A are (x... A ,y A ,z A The coordinates of two adjacent first reference points are (x1, y1, z1) and (x2, y2, z2), respectively. The physical distances between the two first reference points and base station A are L1 and L2.

[0051] A4. Based on the coordinates of the base station in the BeiDou coordinate system obtained in A3, when using UWB for indoor positioning, input the coordinates corresponding to each base station into the host computer, set a tag to be tested indoors, and the absolute coordinates of the tag to be tested in the BeiDou coordinate system can be directly output.

[0052] Example 2:

[0053] This invention provides a coordinate transformation system based on BeiDou RTK and UWB, used to perform the coordinate transformation method of BeiDou RTK and UWB described in Example 1 above, solving the same technical problem and achieving the same technical effect.

[0054] Figure 3 This is a schematic diagram of a coordinate transformation system between BeiDou RTK and UWB provided in Example 3 of the present invention.

[0055] like Figure 3 As shown, the system includes a UWB base station, tags, and a host computer.

[0056] The UWB base station is used to receive and transmit pulse signals from the tag and convert them into coordinate information.

[0057] The aforementioned tag, with the same structure as the UWB base station, serves as the target to be tested and is used to send and receive pulse signals from the base station.

[0058] The host computer can be connected to any one of the base stations via USB, and the host computer software can observe the position coordinates and movement trajectory of the tag under test in real time.

[0059] This example, through the cooperation of base stations, tags, and host computers, can obtain the coordinates of the target under test in the BeiDou coordinate system and its movement trajectory in real time, without the need to customize the coordinates of the UWB base station indoors, thus saving a complicated conversion process.

[0060] The technical principles of the present invention have been described above with reference to specific embodiments. These descriptions are merely for explaining the principles of the invention and should not be construed as limiting the scope of protection of the invention in any way. Based on this explanation, those skilled in the art can readily conceive of other specific embodiments of the invention without inventive effort, and these embodiments will all fall within the scope of protection of the present invention.

Claims

1. A coordinate conversion method based on Beidou RTK and UWB, characterized in that, include: Four UWB base stations are arranged in a rectangle indoors, and four reference points are selected at the boundary between indoors and outdoors, that is, on the four sides of the rectangle. Obtain the absolute coordinates of all selected reference points in the BeiDou coordinate system, and then calculate the absolute coordinates of the four UWB base stations in the BeiDou coordinate system by combining the coordinates of the reference points in pairs. When performing indoor positioning, the position coordinates of the tag to be measured by the UWB base station indoors can be combined with the absolute coordinates of the UWB base station in the BeiDou coordinate system to convert the position coordinates of the tag to be measured indoors into BeiDou coordinates. The method for obtaining any reference point is as follows: Let Q be the reference point selected on one side of the rectangle. At the same time, two reference points S1 and S2 are selected outdoors. The two reference points S1 and S2 and the reference point Q form an isosceles triangle. The absolute coordinates of two reference points S1 and S2 in the BeiDou coordinate system are measured by the BeiDou static solution algorithm, and the physical distance between reference point Q and the two reference points S1 and S2 is measured by physical measurement. The absolute coordinates of reference point Q in the BeiDou coordinate system are then calculated. The absolute coordinates of two reference points S1 and S2 in the BeiDou coordinate system were measured using the BeiDou static solution algorithm, and the physical distance between reference point Q and the two reference points S1 and S2 was measured using physical measurements. The specific calculation formula for the absolute coordinates of reference point Q in the BeiDou coordinate system is as follows: The absolute coordinates of reference point Q in the BeiDou coordinate system are (x, y, z), and the absolute coordinates of the two reference points S1 and S2 in the BeiDou coordinate system are (x1, y1, z1) and (x2, y2, z2) respectively. The physical distances between reference point Q and the two reference points S1 and S2 are d1 and d2 respectively. When performing indoor positioning, there is no need to customize the UWB base station coordinates. The coordinates of the UWB base station can be directly set to the absolute coordinates of the UWB base station in the BeiDou coordinate system, so as to directly output the absolute coordinates of the tag under test in the BeiDou coordinate system, i.e., the BeiDou coordinates.

2. The coordinate conversion method based on Beidou RTK and UWB according to claim 1, characterized in that, The method by which a UWB base station measures the location coordinates of a tag indoors is as follows: By deploying four UWB base stations indoors and using the UWB ranging algorithm, the coordinates of the tag under test in the UWB coordinate system, i.e., its location coordinates, are measured when the tag is indoors.

3. A coordinate conversion system based on Beidou RTK and UWB, applying the method of claim 1 or 2, characterized in that, Includes UWB base stations, tags under test, and host computers; The UWB base station is used to receive and transmit pulse signals from the tag under test and convert them into location coordinate information; The tag under test has the same structure as the UWB base station and serves as the target under test, used to send and receive pulse signals from the UWB base station. The host computer is connected to one of the UWB base stations via USB, and the host computer software can observe the position coordinates and movement trajectory of the tag under test in real time.

4. A coordinate transformation system based on BeiDou RTK and UWB according to claim 3, characterized in that, The UWB base stations consist of four units arranged in a rectangular pattern indoors.

5. A coordinate transformation system based on BeiDou RTK and UWB according to claim 3, characterized in that, The host computer is loaded with a program that executes the method steps described in any one of claims 1-2.

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