Multi-antenna beidou monitoring device and monitoring method

Abstract

The present application relates to the technical field of structural safety monitoring, and specifically relates to a multi-antenna Beidou monitoring device and a monitoring method, wherein 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, the mounting base is used for being fixed to a measured structure, the bottom end of the monitoring pile is fixed to the mounting base, the connecting line of the first positioning antenna, the second positioning antenna and the third positioning antenna forms a triangle, the connecting line of the centroid of the first positioning antenna, the second positioning antenna, the third positioning antenna and the mounting base forms a triangular pyramid, and the mounting cabinet is mounted on the monitoring pile. The present application solves the technical problem that the monitoring pile in the prior art causes abnormal error of Beidou positioning under the condition of self-space displacement interference, thereby causing an error monitoring result.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of structural safety monitoring, and particularly relates to a multi-antenna Beidou monitoring device and a monitoring method. BACKGROUND

[0002] In structural safety monitoring using the Beidou navigation positioning system, the main method is to install a Beidou positioning antenna together with a monitored structure through a monitoring pile (pier), so that when the monitored structure moves in space, the monitoring pile (pier) will also move, and the Beidou positioning antenna installed on the monitoring pile (pier) will also move accordingly. The Beidou receiver receives satellite signals through the positioning antenna, and then calculates the spatial coordinates of the positioning antenna through a variety of algorithms. The change in the spatial coordinates of the positioning antenna reflects the spatial displacement of the monitored structure.

[0003] Since the Beidou positioning antenna needs a good environment to receive signals from a larger number of satellites and to calculate more accurate spatial coordinates, in actual application, the Beidou positioning antenna is installed on a monitoring pile (pier) at a higher position to avoid the obstruction and interference of surrounding objects to the signals.

[0004] However, when the monitored structure moves and drives the monitoring pile (pier) to move, it will not be ideal translational motion, especially when the monitoring pile (pier) is high, it often also accompanies the occurrence of tilting and twisting motion. At this time, the displacement obtained through the positioning antenna includes the true displacement of the structure and the displacement of the monitoring pile itself. If the additional displacement of the monitoring pile is not removed, the result will have errors.

[0005] Chinese patent 202111056061.6 discloses a double-antenna Beidou monitoring method and system suitable for a column. The scheme is that two antennas are arranged on the circumference of the column monitoring object and are collinear with the monitoring point. The satellite coordinates are calculated through ephemeris data, and the single-point precise positioning coordinates of the positioning antenna are calculated, and finally the coordinates of the monitoring point are calculated through geometric relationship. This scheme is only suitable for the positioning of column monitoring objects, and requires that the two Beidou positioning antennas are in the same horizontal plane and are collinear with the monitoring point. When the premise condition is not met due to the displacement or deformation of the structure, the positioning data error calculated will be larger.

[0006] The Chinese patent 201620374597.0 discloses a dual-antenna Beidou short message receiver, both of which adopt a dual-antenna design to ensure high quality of received satellite data, but in the process of utilizing dual-antenna satellite signals, the signal is modulated and filtered, and then the signal quality is compared to select the antenna signal with better quality. However, in the process of processing the signal, distortion of signal transmission is inevitable, so the system will introduce artificial system error, reducing the positioning accuracy; and the circuit for comparing signals also increases the complexity of the system, and the failure rate is also increased. SUMMARY

[0007] The present application aims to provide a multi-antenna Beidou monitoring device and a monitoring method to solve the technical problem of false monitoring results caused by abnormal errors of Beidou positioning under the interference of self-space displacement of the monitoring pile in the prior art, and the specific technical solutions are as follows:

[0008] The present application 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, the mounting base is used for fixing to the measured structure, 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 pile, the middle part of the monitoring pile is provided with two supporting rods, the second positioning antenna and the third positioning antenna are respectively connected to the end parts of the two supporting rods, the connecting line of the first positioning antenna, the second positioning antenna and the third positioning antenna forms a triangle, the connecting line of the centroid of the first positioning antenna, the second positioning antenna, the third positioning antenna and the mounting base forms a triangular pyramid, and the mounting cabinet is installed on the monitoring pile.

[0009] The further improvement of the multi-antenna Beidou monitoring device is that a signal switcher and a Beidou receiver are arranged in the mounting cabinet, the input end of the signal switcher is connected to the first positioning antenna, the second positioning antenna and the third positioning antenna, and the output end of the signal switcher is connected to the Beidou receiver.

[0010] The further improvement of the multi-antenna Beidou monitoring device is that the signal switcher 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 application also provides a method using the multi-antenna Beidou monitoring device as described above, comprising the following steps:

[0012] The first initial position coordinate is obtained by receiving signals through the first positioning antenna, the second initial position coordinate is obtained by receiving signals through the second positioning antenna, the third initial position coordinate is obtained by receiving signals through the third positioning antenna, and the fourth initial position coordinate is the centroid coordinate of the installation base;

[0013] When the monitoring pile moves due to the displacement of the structure, the first moved position coordinate is obtained by receiving signals through the first positioning antenna, the second moved position coordinate is obtained by receiving signals through the second positioning antenna, and the third moved position coordinate is obtained by receiving signals through the third positioning antenna;

[0014] The moved centroid coordinate of the installation base is calculated through the geometric relationship among the first positioning antenna, the second positioning antenna, the third positioning antenna and the centroid of the installation base.

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

[0016] The first moved position coordinate is represented as A( A x , A y , A z ), the second moved position coordinate is represented as B( B x , B y , B z ), and the third moved position coordinate is represented as C( C x ,C y , C z ), let the coordinates of the centroid of the mounting base after movement be D( D x , D y , D z );

[0017] The distance between the first positioning antenna, the second positioning antenna and the third positioning antenna is a known fixed value, but due to the existence of Beidou positioning error, the distance value 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, and the mean value of the deviation is taken as the error value of the system in the current environment e , the calculation formula is as follows:

[0018] ;

[0019] Wherein, 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, represents the distance after movement of the second positioning antenna and the third positioning antenna, represents the distance after movement of the first positioning antenna and the second positioning antenna, represents the distance after movement of the first positioning antenna and the third positioning antenna, represents the initial distance between the second positioning antenna and the third positioning antenna.

[0020] The points of triangle ABC are corrected, wherein the first positioning antenna A is taken as the reference point, ABC is taken as the reference plane, and AB is taken as the reference direction, and the points B and C are adjusted in turn, and the specific method is as follows:

[0021] The coordinates of the fixed point A( A x , A y , A z ) are fixed, and , the corrected coordinates of B are obtained ’ ( B ’ x , B ’ y , B ’ z );

[0022] In the plane ABC, let , , get the modified coordinates C of C ’ ( C ’ x , C ’ y , C ’ z ) of C.

[0023] The further improvement of the multi-antenna Beidou monitoring method is that when the coordinates of the centroid of the mounting base after movement are calculated through the geometric relationship between the first positioning antenna, the second positioning antenna, the third positioning antenna and the centroid of the mounting base, there is a geometric relationship between the first positioning antenna, the second positioning antenna, the third positioning antenna and the centroid of the mounting base as follows:

[0024] ;

[0025] ;

[0026] ;

[0027] According to the above geometric relationship, the following calculation formula is obtained, and the coordinates D of the centroid of the mounting base after movement are obtained by solving simultaneously:

[0028] ;

[0029] ;

[0030] ;

[0031] wherein, represents the distance between A and D, represents the distance between B ’ and D, represents the distance between C ’ and D, represents the distance between A0 and D0, represents the distance between B0 and D0, represents the distance between C0 and D0. D 0x , D 0y , D 0z represents the three-dimensional space coordinates of D0, A 0x ,A 0y 、 A 0z three-dimensional space coordinates of point A0, B 0x 、 B 0y 、 B 0z three-dimensional space coordinates of point B0, C 0x 、 C 0y 、 C 0z three-dimensional space coordinates of point C0.

[0032] Further improvement of the multi-antenna Beidou monitoring method is that when the coordinates of the centroid of the mounting base after movement are calculated through the geometric relationship between the first positioning antenna, the second positioning antenna, the third positioning antenna and the centroid of the mounting base, after monitoring the displacement of the pile, the line connecting the first positioning antenna, the second positioning antenna, the third positioning antenna and the centroid of the mounting base forms a triangular pyramid D-AB ’ C ’ , the coordinates of the projection point H of point D to the plane ABC ’ C ’ are obtained, DH is the height of the triangular pyramid, and the coordinates of point D are obtained by calculating vectors and .

[0033] Further improvement of the multi-antenna Beidou monitoring method is that when the coordinates of the projection point H of point D to the plane ABC ’ C ’ are obtained, the following steps are included:

[0034] On the plane ABC ’ C ’ , a line is drawn from H to the perpendicular to ABC ’ , and the foot is A ’ , that is:

[0035] ;

[0036] ;

[0037] Let , in triangle ABH ’ , the following can be obtained by the cosine formula:

[0038] ;

[0039] is obtained by trigonometric function The value is based on the known points A and B. ’ The coordinates of point A can be obtained by constructing a vector. ’ ’ Coordinates:

[0040] ;

[0041] Right now:

[0042] ;

[0043] in, AH Let H be the length between point A and point H. AD Let A be the length between points A and D. DH The length between point D and point H. For B ’ The length between point H and point H, For B ’ The length between point D and point E. DH The length between point D and point H. From point A to point B ’ The length between points A express A Point coordinates, express Point coordinates, This indicates the distance from point A to point B. ’ Distance between points This indicates the distance from point A to point B. ’ The spatial vector of a point, Indicates point A to A spatial vector of a point.

[0044] A further improvement of the multi-antenna BeiDou monitoring method of the present invention lies in that, by calculating the vector... and When obtaining the coordinates of point D by vector addition, the following steps are involved:

[0045] Vector A is obtained through the cross product of vectors. ’ ’ H, HD, construct a left-handed coordinate system A-XYZ:

[0046] Direction vector of HD:

[0047] ;

[0048] Then perform the cross product:

[0049] ;

[0050] Then the coordinates of point D are obtained:

[0051] ;

[0052] in, This represents the spatial vector from point H to point D. This represents the spatial vector from point A to the Z-axis. This represents the spatial vector from point A to point C'. This represents the spatial vector from point A to the Y-axis. This represents the spatial vector from point A to the A-axis. Indicates the distance from point A to point A. ’ ’ The spatial vector of a point, This represents the spatial vector from point A to point D. A represents ’ ’ The spatial vector from point H to point H.

[0053] The application of the technical solution of the present invention has the following beneficial effects:

[0054] 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, eliminating the interference of the additional displacement of the monitoring pile itself after movement, rotation, or tilting on the true displacement of the monitored point in conventional methods.

[0055] In addition, this invention achieves the function of simultaneously calculating the coordinates of three positioning antennas using a single BeiDou receiver by using a mechanical three-antenna signal switcher. The signal switcher adopts a physical control path method and does not process the signal in any way, thus ensuring the authenticity of the data.

[0056] Simultaneously, based on the known distances of the three antennas and the difference calculated using the spatial coordinates of the three antennas obtained through the BeiDou solution algorithm, the actual error value of the BeiDou solution algorithm under the current environmental conditions was obtained. This provides a very effective reference for the authenticity of the monitoring results and solves the technical problem of abnormal BeiDou positioning errors caused by the spatial displacement interference of the monitoring piles in the existing technology, which leads to erroneous monitoring results.

[0057] In addition to the objectives, features, and advantages described above, the present invention has other objectives, features, and advantages. The invention will now be described in further detail with reference to the figures. Attached Figure Description

[0058] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0059] Figure 1 This is a schematic diagram of the structure of the multi-antenna Beidou monitoring device of the present invention;

[0060] Figure 2is the positional relationship schematic view of 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 application;

[0061] Figure 3 is the positional schematic view of 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 method of the present application when the position of the monitored structure does not change;

[0062] Figure 4 is the positional schematic view of 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 method of the present application after the position of the monitored structure changes;

[0063] Figure 5 is the calculation schematic view of 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 method of the present application after the position of the monitored structure changes, before the correction of the B point and the C point;

[0064] Figure 6 is the calculation schematic view of 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 method of the present application after the position of the monitored structure changes, after the correction of the B point and the C point;

[0065] Figure 7 is the calculation schematic view of 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 method of the present application after the position of the monitored structure does not change;

[0066] Figure 8 is the positioning antenna connection schematic view of the multi-antenna Beidou monitoring device of the present application.

[0067] Wherein, 1, the first positioning antenna, 2, the second positioning antenna, 3, the third positioning antenna, 4, the centroid, 5, the mounting cabinet, 6, the monitoring pile, 7, the mounting base, 8, the mechanical switch, 9, the Beidou receiver, 10, the program. DETAILED DESCRIPTION

[0068] The embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0069] When the Beidou positioning system and the Beidou monitoring pile 6 are used to monitor the displacement of a structure, the additional spatial displacement of the body structure of the monitoring pile 6 can be corrected by the multiple Beidou antenna positioning, so as to accurately reflect the real displacement state of the monitored structure. The three Beidou positioning antennas and the antenna signal switching circuit are designed, so that the position signals of multiple antennas can be acquired by one Beidou receiver 9; the real displacement of the monitoring pile 6 installation point, i.e. the monitored point, can be obtained by using the positions of multiple antennas through a spatial geometric algorithm, so as to eliminate the interference of the self-displacement of the conventional monitoring pile 6 on the displacement of the monitored point.

[0070] Specifically, as shown in Figure 1 and Figure 2 , 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. The mounting base 7 is used to be fixed to a measured structure. 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. The middle part of the monitoring pile 6 is provided with two supporting rods. The second positioning antenna 2 and the third positioning antenna 3 are respectively connected to the end parts of the two supporting rods. The connecting line of the first positioning antenna 1, the second positioning antenna 2 and the third positioning antenna 3 forms a triangle. The connecting 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. The mounting cabinet 5 is installed on the monitoring pile 6.

[0071] Further, as shown in Figure 1 and Figure 3 , the mounting cabinet 5 is provided with a signal switcher and a Beidou receiver 9. The input end of the signal switcher is connected to the first positioning antenna 1, the second positioning antenna 2 and the third positioning antenna 3. The output end of the signal switcher is connected to the Beidou receiver 9.

[0072] Preferably, as shown in Figure 8 , the signal switcher is provided with three mechanical switching switches 8. 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.

[0073] ​Generally, when the Beidou navigation positioning system is used for structural safety monitoring, a mounting base 7 needs to be arranged on the monitored structure, if it is a soil structure such as a slope, a foundation pit will be dug on the slope, and then a mounting 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, and the displacement of the centroid 4 of the mounting base 7 is taken as the displacement of the monitored structure. However, the centroid 4 of the mounting base 7 is generally inside the structure, and its displacement is difficult to measure directly, so the monitoring pile 6 is arranged on the mounting base 7, and the displacement of the centroid 4 of the mounting base 7 is calculated by the displacement of the upper part of the monitoring pile 6.

[0074] The monitoring pile 6 is provided with three non-collinear Beidou positioning antennas, and the lines connecting the three antennas can form a triangle. The three antennas are connected to the signal switcher through the connecting lines, and the output end of the signal switcher is connected to the Beidou receiver 9. The signal switcher is internally provided with a mechanical switching switch 8, which does not process the signal, so that the signal can be guaranteed not to be distorted; the switching time of the signal switcher is controlled by the program 10, and can be remotely adjusted. In this way, one Beidou receiver 9 can be used to solve the position coordinates of multiple positioning antennas, saving equipment cost.

[0075] The three positioning antennas and the centroid 4 of the mounting base 7 (the measuring point reflecting the real displacement of the structure) together form a triangular pyramid, so the problem of calculating the position of the centroid 4 after the displacement of the monitoring pile 6 through the new positions of the three antennas can be converted into the problem of calculating the spatial coordinates of the fourth point, with the spatial coordinates of the three vertices of the known triangular pyramid and the lengths of the six edges.

[0076] As shown in Figure 3 and Figure 4 The application further provides a method using the multi-antenna Beidou monitoring device, comprising the following steps:

[0077] 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, the third initial position coordinates are obtained by receiving signals through the third positioning antenna 3, and the fourth initial position coordinates are obtained by knowing the centroid 4 coordinates of the mounting base 7;

[0078] After the monitoring pile 6 moves due to the displacement of the structure, the first post-displacement position coordinates are obtained by receiving signals through the first positioning antenna 1, the second post-displacement position coordinates are obtained by receiving signals through the second positioning antenna 2, and the third post-displacement position coordinates are obtained by receiving signals through the third positioning antenna 3;

[0079] The coordinates of the centroid 4 of the mounting base 7 after moving are calculated through the geometric relationship between the first positioning antenna 1, the second positioning antenna 2, the third positioning antenna 3 and the centroid 4 of the mounting base 7.

[0080] As Figure 3 and Figure 4 shown, the first initial position coordinate is represented as A0( A x0 , A y0 , A z0 ), the second initial position coordinate is represented as B0( B x0 , B y0 , B z0 ), the third initial position coordinate is represented as C0( C x0 , C y0 , C z0 ), and the fourth initial position coordinate is represented as D0( D x0 , D y0 , D z0 );

[0081] The first moved position coordinate is represented as A( A x , A y , A z ), the second moved position coordinate is represented as B( B x , B y , B z ), the third moved position coordinate is represented as C( C x , C y , C z ), and the fourth moved position coordinate is represented as D( D x , D y , D z );

[0082] It should be noted that the spatial coordinates of the Beidou antenna obtained by the Beidou positioning system adopt a differential positioning solution algorithm, that is, a reference station is also arranged near the monitoring pile 6, and the spatial coordinates of the three positioning antennas are obtained based on the general open source positioning algorithm through the joint of the monitoring station antenna and the reference station antenna.

[0083] 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, the distance value calculated from the spatial coordinates of the three antennas measured will deviate from the fixed value, and the mean value of the deviation is taken as the error value of the system in the current environment e , to represent an error range of the results calculated by the whole system. The calculation formula is as follows:

[0084] ;

[0085] , wherein, 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 post-moved distance between the second positioning antenna 2 and the third positioning antenna 3, represents the post-moved distance between the first positioning antenna 1 and the second positioning antenna 2, represents the post-moved distance between 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;

[0086] As shown in Figure 5 and Figure 6 , due to the existence of Beidou positioning measurement deviation, △A0B0C0 and △ABC are not completely consistent, which leads to the situation that when the distances from point D to the points of △ABC and the distances from point D0 to the points of △A0B0C0 are calculated respectively and they are made equal to each other, it is easy to appear no solution. Therefore, the points of △ABC need to be corrected, wherein the first positioning antenna A is taken as the reference point, ABC is taken as the reference plane, and AB is taken as the reference direction, and then B point and C point are adjusted in turn. The specific method is as follows:

[0087] The coordinates of the fixed point A( A x , A y , A z ) are fixed, and along the direction of AB, , the corrected coordinates B ’ of B are obtained B ’ x , B ’ y , B ’ z ;

[0088] In the plane ABC, , , the modified coordinates of C are obtained ’ ( C ’ x , C ’ y , C ’ z )。

[0089] Example 1: when the coordinates of the centroid 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 centroid 4 of the mounting base 7, there is a geometric relationship between the first positioning antenna 1, the second positioning antenna 2, the third positioning antenna 3 and the centroid 4 of the mounting base 7 as follows:

[0090] ;

[0091] ;

[0092] ;

[0093] According to the above geometric relationship, the following calculation formula is obtained, and the coordinates D of the centroid 4 of the mounting base 7 after movement are obtained by simultaneous solution:

[0094] ;

[0095] ;

[0096] ;

[0097] wherein, represents the distance between the point A and the point D, represents the distance between the point B ’ and the point D, represents the distance between the point C ’ and the point D, represents the distance between the point A0 and the point D0, represents the distance between the point B0 and the point D0, represents the distance between the point C0 and the point D0; D 0x , D 0y , D 0z represents the three-dimensional space coordinates of the point D0, A 0x , A 0y , A 0zRepresents the three-dimensional spatial coordinates of point A0. B 0x , B 0y , B 0z Represents the three-dimensional spatial coordinates of point B0. C 0x , C 0y , C 0z This represents the three-dimensional spatial coordinates of point C0.

[0098] D(D) can be obtained from the above formula. x D y D z Since the solution obtained by this method is not unique, it is necessary to obtain the final unique true solution by applying physical constraints (for example, if the point is theoretically physically constrained to be in the first quadrant, solutions in other quadrants can be excluded) based on the actual situation.

[0099] Example 2: Figure 6 As shown, when the coordinates of the centroid 4 of the mounting base 7 after its movement are calculated using the geometric relationship between the first positioning antenna 1, the second positioning antenna 2, the third positioning antenna 3, and the centroid 4 of the mounting base 7, after monitoring the displacement of the pile 6, the lines connecting the first positioning antenna 1, the second positioning antenna 2, the third positioning antenna 3, and the centroid 4 of the mounting base 7 form a triangular pyramid DA B. ’ C ’ Find the distance from point D to plane AB. ’ C ’ The coordinates of the projection point H on the pyramid are given, and DH is the height of the triangular pyramid. The vector is calculated from this. and The coordinates of point D are obtained by adding vectors.

[0100] Preferably, the distance from point D to surface AB is calculated. ’ C ’ When determining the coordinates of the projection point H on the surface, the following steps are included:

[0101] On face AB ’ C ’ Draw a line from H perpendicular to AB. ’ The foot of the perpendicular is A. ’ ,Right now:

[0102] ;

[0103] ;

[0104] make In △AB’ H can be obtained using the cosine formula:

[0105] ;

[0106] Obtained through trigonometric functions The value, based on the known points A and B ’ The coordinates of point A can be obtained by constructing a vector. ’ ’ Coordinates:

[0107] ;

[0108] Right now:

[0109] ;

[0110] in, AH The length between point A and point H. AD Let A be the length between points A and D. DH The length between point D and point H. For B ’ The length between point H and point H, For B ’ The length between point D and point E. DH The length between point D and point H. From point A to point B ’ The length between points A Represents the coordinates of point A. express The coordinates of the point This represents the distance between point A and point B'. This represents the spatial vector from point A to point B'. Indicates point A to A spatial vector of a point.

[0111] Preferably, by calculating the vector and When obtaining the coordinates of point D by vector addition, the following steps are involved:

[0112] Vector A is obtained through the cross product of vectors. ’ ’ H, HD, construct a left-handed coordinate system A-XYZ:

[0113] Direction vector of HD:

[0114] ;

[0115] Then perform the cross product:

[0116] ;

[0117] Then, the coordinates of point D are obtained (represented by vectors):

[0118] ;

[0119] in, This represents the spatial vector from point H to point D. This represents the spatial vector from point A to the Z-axis. This represents the spatial vector from point A to point C'. This represents the spatial vector from point A to the Y-axis. This represents the spatial vector from point A to the A-axis. Indicates the distance from point A to point A. ’ ’ The spatial vector of a point, This represents the spatial vector from point A to point D. A represents ’ ’ The spatial vector from point H

[0120] The following are application examples of this invention:

[0121] like Figure 7 As shown, before the monitoring pile moves, 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 centroid 4 of the mounting base 7 of the monitoring pile 6 is D0 (0, 1791.5, 0). The four points form a triangular pyramid D0-A0B0C0.

[0122] When the monitoring pile moves due to the displacement of the structure, the phase center point of the first positioning antenna 1 is obtained as A (23, 510.2, 1798.8) after differential positioning calculation using Beidou satellite navigation positioning data; the phase center point of the second positioning antenna 2 is B (263, 314.2, 923.4); the phase center point of the third positioning antenna 3 is C (258, 1110.7, 1116.3); and the center of mass of the monitoring pile 6 is D (the point of mass of the base 7). D x , D y , D z Let be the unknown quantity, and connect the four points to form a new triangular pyramid D-ABC.

[0123] It should be noted that the spatial coordinates of the Beidou antennas are obtained through the Beidou positioning system using a differential positioning algorithm. That is, a base station is also set up near monitoring pile 6, and the spatial coordinates of the three positioning antennas are obtained by combining the two and using algorithms such as error elimination.

[0124] So although the three antennas are rigidly fixed on the monitoring pile 6, the distance between them is a known fixed value, but due to the existence of Beidou positioning error, the distance value calculated from the spatial coordinates of the three antennas measured will deviate from the fixed value, and the mean deviation is taken as the error value of the system in the current environment e . The calculation formula is as follows:

[0125]

[0126] At the same time, due to the existence of Beidou positioning measurement deviation, △A0B0C0 and △ABC are not completely consistent, which leads to the fact that when the distances from point D to each point of △ABC and the distances from point D0 to each point of △A0B0C0 are calculated respectively and they are equal to each other, it is easy to appear no solution. Therefore, the points of △ABC need to be corrected, among which the first positioning antenna A is taken as the reference point, ABC is taken as the reference plane, and AB is taken as the reference direction, and then B and C points are adjusted in turn. The specific method is as follows:

[0127] The coordinates of the fixed point A (23, 510.2, 1798.8) are adjusted along the direction of AB, and let , the corrected coordinates of B are obtained ’ (265.67, 312.02, 913.67);

[0128] In the plane ABC, let , , the corrected coordinates of C are obtained ’ (259.36, 1109.32, 1111.27).

[0129] The solving method of example one is used to solve:

[0130] Since the positions of A0, B0, C0 and D0 are known, and the positions of A, B ’ , C ’ are also known, the coordinates of D D x , D y , D z ) need to be calculated, which has three unknowns, so three equations are constructed to solve the problem in combination with relevant physical constraints.

[0131] If there is the following geometric relationship:

[0132]

[0133]

[0134]

[0135] The calculation formula can be obtained:

[0136]

[0137]

[0138]

[0139] The value of D calculated by the above formula, D x , D y , D z ) is not unique, and the final unique true solution needs to be obtained according to the actual situation and the physically existing constraint condition.

[0140] The multi-antenna Beidou monitoring device calculates the actual displacement of the monitored point through the three-antenna position coordinate inverse calculation method, eliminates the interference of the additional displacement of the monitoring pile 6 on the true displacement of the monitored point after the monitoring pile 6 moves, rotates and tilts. In addition, the three-antenna signal switcher in mechanical form is used to realize the function of simultaneously calculating the coordinates of three positioning antennas by using one Beidou receiver 9. The signal switcher uses a physical control path method and does not process the signal, thereby ensuring the authenticity of the data. At the same time, the difference between the two data, i.e., the known distance of the three antennas and the space coordinates of the three antennas calculated by the Beidou solving algorithm, obtains the actual error value of the Beidou solving algorithm under the current environmental condition, provides a very effective reference for the authenticity of the monitoring result, and solves the technical problem of the error monitoring result caused by the abnormal error of the Beidou positioning under the space displacement interference of the monitoring pile 6 in the prior art.

[0141] The above only describes the preferred embodiments of the present application and is not used to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A multi-antenna BeiDou monitoring method, characterized in that, A multi-antenna Beidou monitoring device is adopted. The 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). The mounting base (7) is used to fix it to the structure under test. 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 pile (6). Two support rods 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 rods. The line connecting the first positioning antenna (1), the second positioning antenna (2), and the third positioning antenna (3) forms a triangle. The line connecting the centroid (4) of the first positioning antenna (1), the second positioning antenna (2), the third positioning antenna (3), and the mounting base (7) forms a triangular pyramid. The mounting cabinet (5) is installed on the monitoring pile (6). 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). It is known that the coordinates of the centroid (4) of the mounting base (7) are the fourth initial position coordinates. When the monitoring pile (6) moves due to the displacement of the structure, the first rear position coordinates are obtained by receiving signals through the first positioning antenna (1), the second rear position coordinates are obtained by receiving signals through the second positioning antenna (2), and the third rear position coordinates are obtained by receiving signals through the third positioning antenna (3). The coordinates of the centroid (4) of the mounting base (7) after its 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 centroid (4) of the mounting base (7); The first initial position coordinates are represented as A0( A x0 , A y0 , A z0 The second initial position coordinates are represented as B0( B x0 , B y0 , B z0 The third initial position coordinates are represented as C0( C x0 , C y0 , C z0 The fourth initial position coordinates are represented as D0( D x0 , D y0 , D z0 ); The first shifted position coordinates are represented as A( A x , A y , A z The second shifted position coordinates are represented as B( B x , B y , B z The third shifted position coordinates are represented as C( C x , C y , C z Let the coordinates of the centroid (4) of the mounting base (7) after its movement be 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 errors, the distance values ​​calculated from the measured spatial coordinates of the first positioning antenna (1), the second positioning antenna (2), and the third positioning antenna (3) will deviate from the fixed values. The average value of the deviations is taken as the error value of the system in the current environment. ε The calculation formula is as follows: ； in, This indicates the initial distance between the first positioning antenna (1) and the second positioning antenna (2). This indicates the initial distance between the first positioning antenna (1) and the third positioning antenna (3). This indicates the distance the second positioning antenna (2) and the third positioning antenna (3) were moved backward. This indicates the distance the first positioning antenna (1) and the second positioning antenna (2) were moved back. This indicates the distance the first positioning antenna (1) and the third positioning antenna (3) were moved back. This indicates the initial distance between the second positioning antenna (2) and the third positioning antenna (3); The points of △ABC are corrected, with the first positioning antenna A as the reference point, ABC as the reference plane, and AB as the reference direction. Points B and C are adjusted sequentially, as follows: Fixed point A ( A x , A y , A z Let the coordinates of ) be along the direction of AB, and let The corrected coordinates of B are obtained. ’ ( B ’ x , B ’ y , B ’ z ); In plane ABC, let , The corrected coordinates of C are obtained. ’ ( C ’ x , C ’ y , C ’ z ).

2. The multi-antenna BeiDou monitoring method according to claim 1, characterized in that, The installation cabinet (5) is equipped with a signal switcher and a Beidou receiver (9). The input end of the signal switcher 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 switcher is connected to the Beidou receiver (9).

3. The multi-antenna BeiDou monitoring method according to claim 2, characterized in that, The signal switcher 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. The multi-antenna BeiDou monitoring method according to claim 3, characterized in that, When calculating the coordinates of the centroid (4) of the mounting base (7) after its movement using the geometric relationship between the first positioning antenna (1), the second positioning antenna (2), the third positioning antenna (3), and the centroid (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 centroid (4) of the mounting base (7): ； ； ； Based on the above geometric relationships, the following calculation formulas are obtained, and the coordinates D of the centroid (4) of the mounting base (7) after its movement are obtained by solving them simultaneously: ； ； ； in, This represents the distance between point A and point D. B ’ The distance between point D and point E. Indicate C ’ The distance between point D and point E. This represents the distance between point A0 and point D0. This represents the distance between point B0 and point D0. This represents the distance between point C0 and point D0; D 0x , D 0y , D 0z Represents the three-dimensional spatial coordinates of point D0. A 0x , A 0y , A 0z Represents the three-dimensional spatial coordinates of point A0. B 0x , B 0y , B 0z Represents the three-dimensional spatial coordinates of point B0. C 0x , C 0y , C 0z This represents the three-dimensional spatial coordinates of point C0.

5. The multi-antenna BeiDou monitoring method according to claim 4, characterized in that, When calculating the coordinates of the centroid (4) of the mounting base (7) after its movement based on the geometric relationship between the first positioning antenna (1), the second positioning antenna (2), the third positioning antenna (3), and the centroid (4) of the mounting base (7), after monitoring the displacement of the pile (6), the line connecting 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 D-AB. ’ C ’ Find the distance from point D to plane AB. ’ C ’ The coordinates of the projection point H on the pyramid are given, and DH is the height of the triangular pyramid. The vector is calculated from this. and The coordinates of point D are obtained by adding vectors.

6. The multi-antenna BeiDou monitoring method according to claim 5, characterized in that, Find the distance from point D to plane AB. ’ C ’ When determining the coordinates of the projection point H on the surface, the following steps are included: On face AB ’ C ’ Draw a line from H perpendicular to AB. ’ The foot of the perpendicular is A. ’ ,Right now: ； ； make In △AB ’ H can be obtained using the cosine formula: ； Obtained through trigonometric functions The value is based on the known points A and B. ’ The coordinates of point A can be obtained by constructing a vector. ’ ’ Coordinates: ； Right now: ； in, AH The length between point A and point H. AD Let A be the length between points A and D. DH The length between point D and point H. For B ’ The length between point H and point H, For B ’ The length between point D and point E. DH The length between point D and point H. From point A to point B ’ The length between points A Represents the coordinates of point A. express The coordinates of the point This represents the distance between point A and point B'. This represents the spatial vector from point A to point B'. Indicates point A to A spatial vector of a point.

7. The multi-antenna BeiDou monitoring method according to claim 6, characterized in that, By calculating the vector and When obtaining the coordinates of point D by vector addition, the following steps are involved: Vector A is obtained through the cross product of vectors. ’ ’ H, HD, construct a left-handed coordinate system A-XYZ: Direction vector of HD: ； Then perform the cross product: ； Then the coordinates of point D are obtained: ； in, This represents the spatial vector from point H to point D. This represents the spatial vector from point A to the Z-axis. This represents the spatial vector from point A to point C'. This represents the spatial vector from point A to the Y-axis. This represents the spatial vector from point A to the A-axis. Indicates the distance from point A to point A. ’ ’ The spatial vector of a point, This represents the spatial vector from point A to point D. A represents ’ ’ The spatial vector from point H to point H.

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