Multi-antenna Beidou monitoring device and monitoring method

Abstract

The invention relates to the technical field of structure safety monitoring, in particular to a multi-antenna Beidou monitoring device and method.The monitoring device comprises a mounting base, a monitoring pile, a mounting cabinet, a first positioning antenna, a second positioning antenna and a third positioning antenna, and the mounting base is used for being fixed to a detected structure; the bottom end of the monitoring pile is fixed on the mounting base, connecting lines of the first positioning antenna, the second positioning antenna and the third positioning antenna form a triangle, and connecting lines of the first positioning antenna, the second positioning antenna, the third positioning antenna and the center of mass of the mounting base form a triangular pyramid. The installation cabinet is installed on the monitoring pile. The technical problem that in the prior art, due to the fact that a monitoring pile causes Beidou positioning abnormal errors under the condition of space displacement interference of the monitoring pile, the monitoring result is wrong is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of structural safety monitoring, and in particular to a multi-antenna Beidou monitoring device and a monitoring method. Background Art

[0002] When using the Beidou navigation and positioning system for structural safety monitoring, the main method is to install the Beidou positioning antenna and the monitored structure together through the monitoring pile (pier). When the monitored structure undergoes spatial displacement, it will drive the monitoring pile (pier) to move, and the Beidou positioning antenna installed on the monitoring pile (pier) will also undergo corresponding displacement. The Beidou receiver receives satellite signals through the positioning antenna, and then the spatial coordinates of the positioning antenna can be obtained through the calculation of multiple algorithms. The changes in the spatial coordinates of the positioning antenna reflect the spatial displacement of the monitored structure.

[0003] Since the Beidou positioning antenna requires a good environment to receive signals from more satellites and calculate more accurate spatial coordinates, in actual applications the Beidou positioning antenna will be installed at a higher position through monitoring piles (piers) to eliminate signal obstruction and interference from surrounding debris.

[0004] However, when the monitored structure moves and drives the monitoring pile (pier) to move, it is not an ideal translation movement. Especially when the monitoring pile (pier) is high, it is often accompanied by tilting and twisting movements. At this time, the displacement obtained by the positioning antenna includes the real displacement of the structure and the displacement of the monitoring pile. If you do not find a way to eliminate the additional displacement of the monitoring pile, the result will be inaccurate.

[0005] Chinese patent 202111056061.6 discloses a dual-antenna Beidou monitoring method and system suitable for columns. This solution arranges dual antennas around the cylindrical monitoring object and in the same line with the point to be monitored; the satellite coordinates are calculated through ephemeris data to cooperate with the single-point precision positioning coordinates of the positioning antenna, and finally the coordinates of the point to be monitored are obtained through geometric relationships. This solution is only applicable to the positioning of cylindrical monitoring objects, and requires that the two Beidou positioning antennas are in the same horizontal plane and in line with the point to be monitored. When the structure is displaced or deformed and the prerequisites are not met, the calculated positioning data error will be relatively large.

[0006] Chinese patent 201620374597.0 discloses a dual-antenna Beidou short message receiver. Both solutions adopt a dual-antenna design to ensure the high quality of the received satellite data. However, in the process of using the dual-antenna satellite signal, the signal is modulated and filtered, and then the signal quality is compared to select the antenna signal with better quality. In the process of processing the signal, it is inevitable that there will be distortion in signal transmission, so the system will have artificially introduced system errors, reducing the positioning accuracy; and adding a signal comparison circuit also makes the system more complex and the failure rate will increase. Summary of the invention

[0007] The object of the present invention is to provide a multi-antenna Beidou monitoring device and a monitoring method to solve the technical problem that the monitoring pile in the prior art causes abnormal Beidou positioning errors under the condition of its own spatial displacement interference, resulting in erroneous monitoring results. The specific technical solution is as follows:

[0008] The present invention provides a multi-antenna Beidou monitoring device, comprising a mounting base, a monitoring pile, a mounting cabinet, a first positioning antenna, a second positioning antenna and a third positioning antenna, wherein the mounting base is used to be fixed to a structure to be measured, the bottom end of the monitoring pile is fixed to the mounting base, the first positioning antenna is connected to the top of the monitoring column, two support poles are provided in the middle of the monitoring pile, the second positioning antenna and the third positioning antenna are respectively connected to the ends of the two support poles, the connection line of the first positioning antenna, the second positioning antenna and the third positioning antenna forms a triangle, the connection line of the first positioning antenna, the second positioning antenna, the third positioning antenna and the centroid of the mounting base forms a triangular pyramid, and the mounting cabinet is installed on the monitoring pile.

[0009] A further improvement of the multi-antenna Beidou monitoring device of the present invention is that a signal switch and a Beidou receiver are provided in the installation cabinet, the input end of the signal switch is connected to the first positioning antenna, the second positioning antenna and the third positioning antenna, and the output end of the signal switch is connected to the Beidou receiver.

[0010] A further improvement of the multi-antenna Beidou monitoring device of the present invention is that the signal switch is provided with three mechanical switching switches, and the first positioning antenna, the second positioning antenna and the third positioning antenna are respectively connected to the three mechanical switching switches.

[0011] The present invention also provides a method using the multi-antenna Beidou monitoring device as described above, comprising the following steps:

[0012] The first initial position coordinates are obtained by receiving signals through the first positioning antenna, the second initial position coordinates are obtained by receiving signals through the second positioning antenna, the third initial position coordinates are obtained by receiving signals through the third positioning antenna, and the centroid coordinates of the known mounting base are the fourth initial position coordinates;

[0013] When the monitoring pile moves due to the displacement of the structure, the first positioning antenna receives a signal to obtain the first moved position coordinates, the second positioning antenna receives a signal to obtain the second moved position coordinates, and the third positioning antenna receives a signal to obtain the third moved position coordinates;

[0014] The coordinates of the center of mass of the mounting base after movement are calculated through the geometric relationship among the first positioning antenna, the second positioning antenna, the third positioning antenna and the center of mass of the mounting base.

[0015] A further improvement of the multi-antenna Beidou monitoring method of the present invention is that the first initial position coordinate is expressed as A0(A x0 ,A y0 ,A z0 ), the second initial position coordinate is expressed as B0(B x0 ,B y0 ,B z0 ), the third initial position coordinate is represented as C0(C x0 ,C y0 ,C z0 ), the fourth initial position coordinate is expressed as D0 (D x0 ,D y0 ,D z0 );

[0016] The first post-shift position coordinate is represented by A(A x ,A y ,A z ), the second shifted position coordinate is expressed as B(B x ,B y ,B z ), the third shifted position coordinate is expressed as C(C x ,C y ,C z ), let the coordinate of the center of mass of the mounting base after moving be D(D x ,D y ,D z );

[0017] The distances between the first positioning antenna, the second positioning antenna, and the third positioning antenna are known fixed values. However, due to the existence of Beidou positioning error, the distance values ​​calculated from the measured spatial coordinates of the first positioning antenna, the second positioning antenna, and the third positioning antenna will deviate from the fixed value. The mean of the deviations is taken as the error value ε of the system in the current environment. The calculation formula is as follows:

[0018]

[0019] in, represents the initial distance between the first positioning antenna and the second positioning antenna, represents the initial distance between the first positioning antenna and the third positioning antenna, Indicates the distance of the second positioning antenna and the third positioning antenna. Indicates the distance between the first positioning antenna and the second positioning antenna. Indicates the distance between the first positioning antenna and the third positioning antenna. represents the initial distance between the second positioning antenna and the third positioning antenna;

[0020] Correct the points of △ABC, taking the first positioning antenna A as the reference point, ABC as the reference plane, AB as the reference direction, and adjust point B and point C in turn. The specific method is as follows:

[0021] Fixed point A(A x ,A y ,A z ) along the direction of AB, let |AB′|=|A0B0|, and get the corrected coordinates of B B'(B' x ,B' y ,B' z );

[0022] In plane ABC, let |AC′|=|A0C0|, |BC|=|B0C0|, and obtain the corrected coordinates C'(C' x ,C' y ,C' z ).

[0023] A further improvement of the multi-antenna Beidou monitoring method of the present invention is that when the coordinates of the center of mass of the mounting base after movement are calculated by using the geometric relationship between the first positioning antenna, the second positioning antenna, the third positioning antenna and the center of mass of the mounting base, the first positioning antenna, the second positioning antenna, the third positioning antenna and the center of mass of the mounting base have the following geometric relationship:

[0024]

[0025] The following calculation formula is obtained based on the above geometric relationship, and the coordinate D of the center of mass of the mounting base after movement is obtained by simultaneous calculation:

[0026]

[0027] in, represents the distance between point A and point D. represents the distance between point B' and point D, represents the distance between point C' and point D, Indicates the distance between point A0 and point D0. It represents the distance between point B0 and point D0. Indicates the distance between point C0 and point D0; D 0x , D 0y , D 0z represents the three-dimensional space coordinates of point D0, A 0x , A 0y , A 0z represents the three-dimensional space coordinates of point A0, B 0x , B 0y , B 0z represents the three-dimensional space coordinates of point B0, C 0x , C 0y , C 0z Represents the three-dimensional space coordinates of point C0.

[0028] A further improvement of the multi-antenna Beidou monitoring method of the present invention is that when the coordinates of the center of mass of the mounting base after movement are calculated by the geometric relationship between the first positioning antenna, the second positioning antenna, the third positioning antenna and the center of mass of the mounting base, after the monitoring pile is displaced, the lines between the first positioning antenna, the second positioning antenna, the third positioning antenna and the center of mass of the mounting base form a triangular pyramid D-AB'C', and the coordinates of the projection point H of point D on the surface AB'C' are obtained, and DH is the height of the triangular pyramid, and the vector is calculated. and The coordinates of point D are obtained by vector addition.

[0029] A further improvement of the multi-antenna Beidou monitoring method of the present invention is that when calculating the coordinates of the projection point H from point D to the surface AB'C', the method includes the following steps:

[0030] On the surface AB'C', draw a perpendicular line from H to AB', with the foot of the perpendicular being A', that is:

[0031]

[0032] Let ∠HAB′=θ, and in △AB'H, we can obtain the following by using the cosine formula:

[0033]

[0034] The value of AA″ is obtained through trigonometric functions. Based on the known coordinates of points A and B', the coordinates of point A" can be obtained by constructing a vector:

[0035]

[0036] Right now:

[0037]

[0038] Among them, AH is the length between point A and point H, AD is the length between point A and point D, DH is the length between point D and point H, B′H is the length between point B' and point H, B′D is the length between point B' and point D, DH is the length between point D and point H, AB′ is the length between point A and point B', A represents the coordinates of point A, and A” represents the coordinates of point A”. It represents the distance between point A and point B'. Represents the space vector from point A to point B', Represents the space vector from point A to point A”.

[0039] A further improvement of the multi-antenna Beidou monitoring method of the present invention is that by calculating the vector and When the coordinates of point D are obtained by vector addition, the following steps are included:

[0040] Use vector cross multiplication to obtain vectors A”H, HD and construct the left-handed coordinate system A-XYZ:

[0041] Direction vector of HD:

[0042]

[0043] Then do the cross product:

[0044]

[0045] Then find the coordinates of point D:

[0046]

[0047] in, represents the space vector from point H to point D, Represents the space vector from point A to the Z axis, Represents the space vector from point A to point C', Represents the space vector from point A to the Y axis, Represents the space vector from point A to axis A, Represents the space vector from point A to point A”, Represents the space vector from point A to point D, Represents the space vector from point A" to point H.

[0048] The application of the technical solution of the present invention has the following beneficial effects:

[0049] The multi-antenna Beidou monitoring device of the present invention obtains the actual displacement of the monitored point by inverse calculation of the position coordinates of the three antennas, thereby eliminating the interference of the additional displacement of the monitoring pile itself on the real displacement of the monitored point after the monitoring pile moves, rotates and tilts in the conventional method.

[0050] In addition, the present invention realizes the function of simultaneously solving the coordinates of three positioning antennas using one Beidou receiver through three mechanical antenna signal switches. The signal switch adopts a physical control path method and does not perform any processing on the signal, thereby ensuring the authenticity of the data.

[0051] At the same time, based on the known distances between the three antennas and the difference between the spatial coordinates of the three antennas obtained by the Beidou solution algorithm, the actual error value of the Beidou solution algorithm under the current environmental conditions is obtained, which provides a very effective reference for the authenticity of the monitoring results and solves the technical problem in the prior art that the monitoring piles cause abnormal Beidou positioning errors under the interference of their own spatial displacement, resulting in erroneous monitoring results.

[0052] In addition to the above-described purposes, features and advantages, the present invention has other purposes, features and advantages. The present invention will be further described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0054] Figure 1 It is a structural schematic diagram of a multi-antenna Beidou monitoring device of the present invention;

[0055] Figure 2 It is a schematic diagram of the positional relationship between the first positioning antenna, the second positioning antenna, the third positioning antenna and the centroid of the mounting base of the multi-antenna Beidou monitoring device of the present invention;

[0056] Figure 3 It is a schematic diagram of the positions of the first positioning antenna, the second positioning antenna, the third positioning antenna and the center of mass of the mounting base of the multi-antenna Beidou monitoring method of the present invention when the monitored structure is not in position;

[0057] Figure 4 It is a schematic diagram of the positions of the first positioning antenna, the second positioning antenna, the third positioning antenna and the center of mass of the mounting base of the multi-antenna Beidou monitoring method of the present invention after the monitored structure is positioned;

[0058] Figure 5 It is a schematic diagram of calculation of the center of mass of the first positioning antenna, the second positioning antenna, the third positioning antenna and the mounting base of the multi-antenna Beidou monitoring method of the present invention after the monitored structure is located, and before the correction of point B and point C;

[0059] Figure 6 It is a schematic diagram of calculation after the center of mass of the first positioning antenna, the second positioning antenna, the third positioning antenna and the mounting base of the multi-antenna Beidou monitoring method of the present invention is located at the position of the monitored structure, and the point B and the point C are corrected;

[0060] Figure 7 1 is a calculation schematic diagram of a first embodiment of a multi-antenna Beidou monitoring method of the present invention;

[0061] Figure 8 It is a schematic diagram of the connection of positioning antennas of the multi-antenna Beidou monitoring device of the present invention.

[0062] Among them, 1. The first positioning antenna, 2. The second positioning antenna, 3. The third positioning antenna, 4. The center of mass, 5. The installation cabinet, 6. The monitoring pile, 7. The installation base, 8. The mechanical switching switch, 9. The Beidou receiver, and 10. The program. DETAILED DESCRIPTION

[0063] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0064] When the displacement of a structure is monitored using the Beidou positioning system and the Beidou monitoring pile 6, the present invention can correct the additional spatial displacement of the main structure of the monitoring pile 6 through multiple Beidou antenna positioning, thereby accurately reflecting the real displacement state of the monitored structure. The present invention realizes the acquisition of multiple antenna position signals simultaneously through one Beidou receiver 9 by designing three Beidou positioning antennas and an antenna signal switching circuit; the real displacement of the installation point of the monitoring pile 6, i.e., the monitored point, can be obtained by using the positions of multiple antennas through a spatial geometric algorithm, thereby eliminating the interference of the conventional monitoring pile 6's own displacement on the displacement of the monitored point.

[0065] For details, see Figure 1 and Figure 2As shown, a multi-antenna Beidou monitoring device includes a mounting base 7, a monitoring pile 6, a mounting cabinet 5, a first positioning antenna 1, a second positioning antenna 2 and a third positioning antenna 3, wherein the mounting base 7 is used to be fixed to a structure to be measured, the bottom end of the monitoring pile 6 is fixed on the mounting base 7, the first positioning antenna 1 is connected to the top of the monitoring column, two support poles are provided in the middle of the monitoring pile 6, the second positioning antenna 2 and the third positioning antenna 3 are respectively connected to the ends of the two support poles, the connection line of the first positioning antenna 1, the second positioning antenna 2 and the third positioning antenna 3 forms a triangle, the connection line of the first positioning antenna 1, the second positioning antenna 2, the third positioning antenna 3 and the center of mass 4 of the mounting base 7 forms a triangular pyramid, and the mounting cabinet 5 is installed on the monitoring pile 6.

[0066] Furthermore, if Figure 1 and Figure 3 As shown, a signal switch and a Beidou receiver 9 are provided in the installation cabinet 5, the input end of the signal switch is connected to the first positioning antenna 1, the second positioning antenna 2 and the third positioning antenna 3, and the output end of the signal switch is connected to the Beidou receiver 9.

[0067] Preferably, Figure 8 As shown, the signal switch is provided with three mechanical switching switches 8, and the first positioning antenna 1, the second positioning antenna 2 and the third positioning antenna 3 are respectively connected to the three mechanical switching switches 8.

[0068] Generally, when the Beidou navigation and positioning system is used for structural safety monitoring, it is necessary to set up a mounting base 7 on the monitored structure. If the monitoring is for soil structures such as slopes, a foundation pit will be dug on the slope, and then the base will be cast with steel bars and concrete. If it is a steel structure such as a bridge, the mounting base 7 will be welded or bolted to install, and the displacement of the center of mass 4 of the mounting base 7 is used as the displacement of the monitored structure. However, the center of mass 4 of the mounting base 7 is generally inside the structure, and its displacement is difficult to measure directly. Therefore, the present invention sets a monitoring pile 6 on the mounting base 7, and calculates the displacement of the center of mass 4 of the mounting base 7 by the displacement of the upper part of the monitoring pile 6.

[0069] The present invention is provided with three non-collinear Beidou positioning antennas on the monitoring pile 6, and the three antennas can be connected to form a triangle. The three antennas are connected to the signal switcher through connecting lines, and the output end of the signal switcher is connected to the Beidou receiver 9. The signal switcher has a mechanical switching switch 8 inside, which does not process the signal and can ensure that the signal is not distorted; the switching timing of the signal switcher is controlled by the program 10 and can be adjusted remotely. In this way, the position coordinates of multiple positioning antennas can be solved by using one Beidou receiver 9, saving equipment costs.

[0070] The lines connecting the three positioning antennas and the center of mass 4 of the mounting base 7 (the measuring point reflecting the real displacement of the structure) together form a triangular pyramid. Therefore, after the displacement of the monitoring pile 6, the problem of calculating the position of the center of mass 4 through the new positions of the three antennas can be converted into the problem of calculating the spatial coordinates of the three vertices and the lengths of the six edges of the known triangular pyramid, and the spatial coordinates of the fourth point.

[0071] like Figure 3 and Figure 4 As shown, the present invention also provides a method using the multi-antenna Beidou monitoring device as described above, comprising the following steps:

[0072] The first initial position coordinates are obtained by receiving signals through the first positioning antenna 1, the second initial position coordinates are obtained by receiving signals through the second positioning antenna 2, and the third initial position coordinates are obtained by receiving signals through the third positioning antenna 3. The coordinates of the center of mass 4 of the mounting base 7 are known to be the fourth initial position coordinates;

[0073] When the monitoring pile 6 moves due to the displacement of the structure, the first positioning antenna 1 receives signals to obtain the first moved position coordinates, the second positioning antenna 2 receives signals to obtain the second moved position coordinates, and the third positioning antenna 3 receives signals to obtain the third moved position coordinates;

[0074] The coordinates of the center of mass 4 of the mounting base 7 after movement are calculated through the geometric relationship among the first positioning antenna 1 , the second positioning antenna 2 , the third positioning antenna 3 and the center of mass 4 of the mounting base 7 .

[0075] like Figure 3 and Figure 4 As shown, the first initial position coordinate is represented by A0(A x0 ,A y0 ,A z0 ), the second initial position coordinate is expressed as B0(B x0 ,B y0 ,B z0 ), the third initial position coordinate is represented as C0(C x0 ,C y0 ,C z0 ), the fourth initial position coordinate is expressed as D0 (D x0 ,D y0 ,D z0 );

[0076] The first post-shift position coordinate is represented by A(A x ,A y ,A z ), the second shifted position coordinate is expressed as B(B x ,B y ,B z), the third shifted position coordinate is expressed as C(C x ,C y ,C z ), assuming that the coordinates of the mass center 4 of the mounting base 7 after movement are D(D x ,D y ,D z );

[0077] It should be noted that the spatial coordinates of the Beidou antenna are obtained through the Beidou positioning system using a differential positioning solution algorithm, that is, a reference station is also set up near the monitoring pile 6, and the spatial coordinates of the three positioning antennas are obtained by combining the monitoring station antenna and the reference station antenna based on a general open source positioning algorithm.

[0078] Although the three antennas are rigidly fixed on the monitoring pile 6, and the distance between them is a known fixed value, due to the existence of Beidou positioning error, there will be a deviation between the distance value calculated from the measured spatial coordinates of the three antennas and the fixed value. The mean of the deviations is taken as the error value ε of the system in the current environment, which is used to characterize an error range of the result calculated by the entire system. The calculation formula is as follows:

[0079]

[0080] in, represents the initial distance between the first positioning antenna 1 and the second positioning antenna 2, represents the initial distance between the first positioning antenna 1 and the third positioning antenna 3, represents the distance of the second positioning antenna 2 and the third positioning antenna 3. represents the distance between the first positioning antenna 1 and the second positioning antenna 2. represents the distance of the first positioning antenna 1 and the third positioning antenna 3. represents the initial distance between the second positioning antenna 2 and the third positioning antenna 3;

[0081] like Figure 5 and Figure 6 As shown in the figure, due to the existence of Beidou positioning measurement deviation, △A0B0C0 and △ABC are not completely consistent, which leads to the situation that there is no solution when calculating the distance from point D to each point of △ABC and the distance from point D0 to each point of △A0B0C0 and making them equal one by one. Therefore, it is necessary to correct each point of △ABC, where the first positioning antenna A is used as the reference point, ABC is used as the reference plane, AB is used as the reference direction, and points B and C are adjusted in turn. The specific method is as follows:

[0082] Fixed point A(A x ,A y ,A z) along the direction of AB, let |AB′|=|A0B0|, and get the corrected coordinates of B B'(B' x ,B' y ,B' z );

[0083] In plane ABC, let |AC′|=|A0C0|, |BC|=|B0C0|, and obtain the corrected coordinates C'(C' x ,C' y ,C' z ).

[0084] Embodiment 1: When the coordinates of the center of mass 4 of the mounting base 7 after movement are calculated by using the geometric relationship between the first positioning antenna 1, the second positioning antenna 2, the third positioning antenna 3 and the center of mass 4 of the mounting base 7, the following geometric relationship exists between the first positioning antenna 1, the second positioning antenna 2, the third positioning antenna 3 and the center of mass 4 of the mounting base 7:

[0085]

[0086] The following calculation formula is obtained based on the above geometric relationship, and the coordinate D of the center of mass 4 of the mounting base 7 after movement is obtained by simultaneous calculation:

[0087]

[0088]

[0089] in, represents the distance between point A and point D. represents the distance between point B' and point D, represents the distance between point C' and point D, Indicates the distance between point A0 and point D0. It represents the distance between point B0 and point D0. Indicates the distance between point C0 and point D0; D 0x , D 0y , D 0z represents the three-dimensional space coordinates of point D0, A 0x , A 0y , A 0z represents the three-dimensional space coordinates of point A0, B 0x , B 0y , B 0z represents the three-dimensional space coordinates of point B0, C 0x , C 0y , C 0z Represents the three-dimensional space coordinates of point C0.

[0090] The above formula can be used to calculate D(D x ,D y ,D z ), since the solution obtained by this method is not unique, it is also necessary to obtain the final unique true solution based on the actual situation through physical constraints (for example, theoretically, if the point is physically constrained to be in the first quadrant, the solutions in other quadrants can be excluded).

[0091] Embodiment 2: Figure 6 As shown, when the coordinates of the mass center 4 of the mounting base 7 after the movement are calculated by the geometric relationship between the first positioning antenna 1, the second positioning antenna 2, the third positioning antenna 3 and the mass center 4 of the mounting base 7, after the monitoring pile 6 is displaced, the lines between the first positioning antenna 1, the second positioning antenna 2, the third positioning antenna 3 and the mass center 4 of the mounting base 7 form a triangular pyramid D-AB'C', and the coordinates of the projection point H of the point D on the surface AB'C' are obtained, and DH is the height of the triangular pyramid. By calculating the vector and The coordinates of point D are obtained by vector addition.

[0092] Preferably, when calculating the coordinates of the projection point H of point D onto the surface AB'C', the following steps are included:

[0093] On the surface AB'C', draw a perpendicular line from H to AB', with the foot of the perpendicular being A', that is:

[0094]

[0095] Let ∠HAB′=θ, and in △AB'H, we can obtain the following by using the cosine formula:

[0096]

[0097] The value of AA″ is obtained through trigonometric functions. Based on the known coordinates of points A and B', the coordinates of point A" can be obtained by constructing a vector:

[0098]

[0099] Right now:

[0100]

[0101] Among them, AH is the length between point A and point H, AD is the length between point A and point D, DH is the length between point D and point H, B′H is the length between point B' and point H, B′D is the length between point B' and point D, DH is the length between point D and point H, AB′ is the length between point A and point B', A represents the coordinate of point A, and A” represents the coordinate of point A”. It represents the distance between point A and point B'. Represents the space vector from point A to point B', Represents the space vector from point A to point A”.

[0102] Preferably, by calculating the vector and When the coordinates of point D are obtained by vector addition, the following steps are included:

[0103] Use vector cross multiplication to obtain vectors A”H, HD and construct the left-handed coordinate system A-XYZ:

[0104] Direction vector of HD:

[0105]

[0106] Then do the cross product:

[0107]

[0108] Then find the coordinates of point D (using vectors to represent coordinates):

[0109]

[0110] in, represents the space vector from point H to point D, Represents the space vector from point A to the Z axis, Represents the space vector from point A to point C', Represents the space vector from point A to the Y axis, Represents the space vector from point A to axis A, Represents the space vector from point A to point A”, Represents the space vector from point A to point D, Represents the space vector from point A" to point H

[0111] The following are application examples of the present invention:

[0112] like Figure 7 As shown, before the monitoring pile is moved, the phase center point of the first positioning antenna 1 is A0 (0, 1791.5, 2161), the phase center point of the second positioning antenna 2 is B0 (250, 1364.5, 1363), the phase center point of the third positioning antenna 3 is C0 (250, 2185.7, 1342.7), and the center of mass 4 of the mounting base 7 of the monitoring pile 6 is D0 (0, 1791.5, 0). The line connecting the four points forms a triangular pyramid D0-A0B0C0.

[0113] When the monitoring pile moves due to the displacement of the structure, the phase center point of the first positioning antenna 1 is A (23, 510.2, 1798.8), the phase center point of the second positioning antenna 2 is B (263, 314.2, 923.4), and the phase center point of the third positioning antenna 3 is C (258, 1110.7, 1116.3). The monitoring pile 6 is installed on the base 7 of the centroid 4 point D (D x ,D y ,D z ) is the quantity to be determined, and the lines connecting the four points form a new triangular pyramid D-ABC.

[0114] It should be noted that the spatial coordinates of the Beidou antenna are obtained through the Beidou positioning system using a differential positioning solution algorithm, that is, a reference station is also set up near the monitoring pile 6, and the spatial coordinates of the three positioning antennas are obtained by combining the two based on algorithms such as error elimination.

[0115] Therefore, although the three antennas are rigidly fixed on the monitoring pile 6 and the distance between them is a known fixed value, due to the existence of Beidou positioning error, there will be a deviation between the distance value calculated from the measured spatial coordinates of the three antennas and the fixed value. The mean of the deviations is taken as the error value ε of the system in the current environment. The calculation formula is as follows:

[0116]

[0117] At the same time, due to the existence of Beidou positioning measurement deviation, △A0B0C0 and △ABC are not completely consistent, which leads to the situation that there is no solution when calculating the distance from point D to each point of △ABC and the distance from point D0 to each point of △A0B0C0 and making them equal one by one. Therefore, it is necessary to correct each point of △ABC, where the first positioning antenna A is used as the reference point, ABC is used as the reference plane, AB is used as the reference direction, and points B and C are adjusted in turn. The specific method is as follows:

[0118] The coordinates of the fixed point A (23, 510.2, 1798.8) are set along the direction of AB, and |AB′|=|A0B0|, and the corrected coordinates of B are obtained as B'(265.67, 312.02, 913.67);

[0119] In plane ABC, let |AC′|=|A0C0|, |BC′|=|B0C0|, and obtain the corrected coordinates C' (259.36, 1109.32, 1111.27) of C.

[0120] The solution is obtained by using the solution method of Example 1:

[0121] Since the positions of A0, B0, C0, and D0 are all known, and the positions of A, B', and C' are also known, we need to find D(D x ,D y ,D z ) has three unknowns, so we can solve it by constructing three equations and combining them with relevant physical constraints.

[0122] If the following geometric relationship exists:

[0123]

[0124] The calculation formula can be obtained:

[0125]

[0126] The above formula can be used to calculate D(D x ,D y ,D z ), since the solution obtained by this method is not unique, it is also necessary to obtain the final unique true solution based on the actual situation and the physical constraints.

[0127] The multi-antenna Beidou monitoring device of the present invention obtains the actual displacement of the monitored point by the method of inverse calculation of the position coordinates of the three antennas, eliminating the interference of the additional displacement of the monitoring pile 6 on the real displacement of the monitored point after the monitoring pile 6 moves, rotates, and tilts in the conventional method. In addition, the present invention realizes the function of using one Beidou receiver 9 to simultaneously solve the coordinates of three positioning antennas through three mechanical antenna signal switches. The signal switch adopts a physical control path method and does not process the signal in any way, thereby ensuring the authenticity of the data. At the same time, based on the known distances of the three antennas and the difference calculated based on the spatial coordinates of the three antennas obtained by the Beidou solution algorithm, the actual error value of the Beidou solution algorithm under the current environmental conditions is obtained, which provides a very effective reference for the authenticity of the monitoring results, and solves the technical problem that the monitoring pile 6 in the prior art causes abnormal Beidou positioning errors under the interference of its own spatial displacement, resulting in erroneous monitoring results.

[0128] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A multi-antenna Beidou monitoring device, characterized in that: The invention comprises a mounting base (7), a monitoring pile (6), a mounting cabinet (5), a first positioning antenna (1), a second positioning antenna (2) and a third positioning antenna (3); the mounting base (7) is used to be fixed to a structure to be measured; the bottom end of the monitoring pile (6) is fixed to the mounting base (7); the first positioning antenna (1) is connected to the top of the monitoring pile; two supporting rods are arranged in the middle of the monitoring pile (6); the second positioning antenna (2) and the third positioning antenna (3) are respectively connected to the ends of the two supporting rods; the connection line of the first positioning antenna (1), the second positioning antenna (2) and the third positioning antenna (3) forms a triangle; the connection line of the first positioning antenna (1), the second positioning antenna (2), the third positioning antenna (3) and the centroid (4) of the mounting base (7) forms a triangular pyramid; and the mounting cabinet (5) is mounted on the monitoring pile (6).

2. The multi-antenna Beidou monitoring device according to claim 1, characterized in that: A signal switch and a Beidou receiver (9) are arranged in the installation cabinet (5); an input end of the signal switch is connected to the first positioning antenna (1), the second positioning antenna (2) and the third positioning antenna (3); and an output end of the signal switch is connected to the Beidou receiver (9).

3. The multi-antenna Beidou monitoring device according to claim 2, characterized in that: The signal switch is provided with three mechanical switching switches (8), and the first positioning antenna (1), the second positioning antenna (2) and the third positioning antenna (3) are respectively connected to the three mechanical switching switches (8).

4. A multi-antenna Beidou monitoring method, characterized in that: Using the multi-antenna Beidou monitoring device as claimed in claim 1, the multi-antenna Beidou monitoring method comprises the following steps: The first initial position coordinates are obtained by receiving signals through the first positioning antenna (1), the second initial position coordinates are obtained by receiving signals through the second positioning antenna (2), and the third initial position coordinates are obtained by receiving signals through the third positioning antenna (3), and the coordinates of the center of mass (4) of the mounting base (7) are known to be the fourth initial position coordinates; When the monitoring pile (6) moves due to the displacement of the structure, the first positioning antenna (1) receives signals to obtain the first moved position coordinates, the second positioning antenna (2) receives signals to obtain the second moved position coordinates, and the third positioning antenna (3) receives signals to obtain the third moved position coordinates; The coordinates of the center of mass (4) of the mounting base (7) after movement are calculated through the geometric relationship between the first positioning antenna (1), the second positioning antenna (2), the third positioning antenna (3) and the center of mass (4) of the mounting base (7).

5. The multi-antenna Beidou monitoring method according to claim 4, characterized in that: The first initial position coordinate is represented by A0(A x0 ,A y0 ,A z0 ), the second initial position coordinate is expressed as B0(B x0 ,B y0 ,B z0 ), the third initial position coordinate is represented as C0(C x0 ,C y0 ,C z0 ), the fourth initial position coordinate is expressed as D0 (D x0 ,D y0 ,D z0 ); The first post-shift position coordinate is represented by A(A x ,A y ,A z ), the second shifted position coordinate is expressed as B(B x ,B y ,B z ), the third shifted position coordinate is expressed as C(C x ,C y ,C z ), assuming that the coordinates of the mass center (4) of the mounting base (7) after moving are D(D x ,D y ,D z ); The distances between the first positioning antenna (1), the second positioning antenna (2) and the third positioning antenna (3) are known fixed values. However, due to the existence of Beidou positioning error, there is a deviation between the distance value calculated from the measured spatial coordinates of the first positioning antenna (1), the second positioning antenna (2) and the third positioning antenna (3) and the fixed value. The mean value of the deviation is taken as the error value ε of the system in the current environment. The calculation formula is as follows: in, represents the initial distance between the first positioning antenna (1) and the second positioning antenna (2), represents the initial distance between the first positioning antenna (1) and the third positioning antenna (3), represents the distance of the second positioning antenna (2) and the third positioning antenna (3) moved back, represents the distance of the first positioning antenna (1) and the second positioning antenna (2) moved back, represents the distance of displacement of the first positioning antenna (1) and the third positioning antenna (3), represents the initial distance between the second positioning antenna (2) and the third positioning antenna (3); Correct the points of △ABC, taking the first positioning antenna A as the reference point, ABC as the reference plane, AB as the reference direction, and adjust point B and point C in turn. The specific method is as follows: Fixed point A(A x ,A y ,A z ) along the direction of AB, let |AB′|=|A0B0|, and get the corrected coordinates of B B'(B' x ,B' y ,B' z ); In plane ABC, let |AC′|=|A0C0|, |BC|=|B0C0|, and obtain the corrected coordinates C'(C' x ,C' y ,C' z ).

6. The multi-antenna Beidou monitoring method according to claim 5, characterized in that: When the coordinates of the center of mass (4) of the mounting base (7) after movement are calculated through the geometric relationship between the first positioning antenna (1), the second positioning antenna (2), the third positioning antenna (3) and the center of mass (4) of the mounting base (7), the following geometric relationship exists between the first positioning antenna (1), the second positioning antenna (2), the third positioning antenna (3) and the center of mass (4) of the mounting base (7): The following calculation formula is obtained based on the above geometric relationship, and the coordinate D of the center of mass (4) of the mounting base (7) after the movement is obtained by simultaneous calculation: in, represents the distance between point A and point D. represents the distance between point B' and point D, represents the distance between point C' and point D, Indicates the distance between point A0 and point D0. It represents the distance between point B0 and point D0. Indicates the distance between point C0 and point D0; D 0x , D 0y , D 0z represents the three-dimensional space coordinates of point D0, A 0x , A 0y , A 0z represents the three-dimensional space coordinates of point A0, B 0x , B 0y , B 0z represents the three-dimensional space coordinates of point B0, C 0x , C 0y , C 0z Represents the three-dimensional space coordinates of point C0.

7. The multi-antenna Beidou monitoring method according to claim 5, characterized in that: When the coordinates of the center of mass (4) of the mounting base (7) after the movement are calculated by the geometric relationship between the first positioning antenna (1), the second positioning antenna (2), the third positioning antenna (3) and the center of mass (4) of the mounting base (7), after the monitoring pile (6) is displaced, the lines connecting the first positioning antenna (1), the second positioning antenna (2), the third positioning antenna (3) and the center of mass (4) of the mounting base (7) form a triangular pyramid D-AB'C', and the coordinates of the projection point H of the point D onto the surface AB'C' are obtained, and DH is the height of the triangular pyramid. By calculating the vector and The coordinates of point D are obtained by vector addition.

8. The multi-antenna Beidou monitoring method according to claim 7, characterized in that: When calculating the coordinates of the projection point H of point D onto the surface AB'C', the following steps are included: On the surface AB'C', draw a perpendicular line from H to AB', with the foot of the perpendicular being A', that is: Let ∠HAB′=θ, and in △AB'H, we can obtain the following by using the cosine formula: The value of AA″ is obtained through trigonometric functions. Based on the known coordinates of points A and B', the coordinates of point A" can be obtained by constructing a vector: Right now: Among them, AH is the length between point A and point H, AD is the length between point A and point D, DH is the length between point D and point H, B′H is the length between point B' and point H, B′D is the length between point B' and point D, DH is the length between point D and point H, AB′ is the length between point A and point B', A represents the coordinate of point A, and A” represents the coordinate of point A”. It represents the distance between point A and point B'. Represents the space vector from point A to point B', Represents the space vector from point A to point A”.

9. The multi-antenna Beidou monitoring method according to claim 8, characterized in that: By calculating the vector and When the coordinates of point D are obtained by vector addition, the following steps are included: Use vector cross multiplication to obtain vectors A”H, HD and construct the left-handed coordinate system A-XYZ: Direction vector of HD: Then do the cross product: Then find the coordinates of point D: in, represents the space vector from point H to point D, Represents the space vector from point A to the Z axis, Represents the space vector from point A to point C', Represents the space vector from point A to the Y axis, Represents the space vector from point A to axis A, Represents the space vector from point A to point A”, Represents the space vector from point A to point D, Represents the space vector from point A" to point H.

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