RTK-GNSS-based structural deformation monitoring method

Abstract

The embodiment of the invention discloses a structural deformation monitoring method based on RTK-GNSS, and relates to the technical field of deformation monitoring, and the method comprises the steps: constructing a double-difference pseudo-range observation equation and a double-difference carrier phase observation equation; acquiring initial positions of the base station and the monitoring station, and respectively acquiring an initial single-difference distance and an initial single-difference distance; calculating a second coordinate offset based on the coordinate offset of the reference station in the current epoch, the first initial single-difference distance and the second initial single-difference distance in combination with a double-difference pseudo-range observation equation and a double-difference carrier phase observation equation; and analyzing the deformation quantity of the to-be-measured structural body based on the second coordinate offset. The method provided by the invention overcomes the defects of unstable positioning and difficulty in ambiguity fixation caused by easy shielding or interference of GNSS signals in part of scenes in related technologies, can stably and efficiently calculate and obtain accurate ambiguity, can realize deformation monitoring in complex scenes, and has the advantages of stable positioning result and high deformation monitoring precision.

Description

Technical Field

[0001] The present application relates to the technical field of deformation monitoring, and in particular to a structural deformation monitoring method based on RTK-GNSS. Background Art

[0002] The Global Navigation Satellite System (GNSS) can be used for health monitoring of civil engineering, water conservancy and other engineering structures, and can be specifically used for deformation and vibration monitoring of bridges and high-rise buildings.

[0003] GNSS positioning can adopt the regional reference network enhanced precise point positioning (PPP-RTK, Precise Point Positioning-Real Time Kinematic) mode, which can provide real-time phase deviation products and high-precision atmospheric delay errors, and support rapid fixation of ambiguities and instantaneous centimeter-level positioning accuracy. RTK can use differential strategies to eliminate spatial correlation delays between monitoring stations and reference stations in real time, thereby obtaining high-precision relative positioning results. The advantage of RTK is that it can eliminate errors related to satellites and receivers through differences in observation values, and reduce space-related errors such as tropospheric and ionospheric delay errors, thereby quickly obtaining the precise coordinates of the monitoring station. However, high-rise buildings and bridges are usually located in urban areas, and GNSS signals are easily blocked by dense urban buildings. It is difficult to place reference stations in open areas for bridge monitoring, which greatly reduces the quality of GNSS observations.

[0004] Therefore, the motion positioning accuracy of PPP-RTK cannot meet the needs of millimeter-level precision deformation and vibration monitoring of bridges and high-rise buildings in urban areas. Summary of the invention

[0005] The embodiment of the present application provides a structural deformation monitoring method based on RTK-GNSS to solve the defects of the above-mentioned related technologies. The technical solution is as follows:

[0006] In a first aspect, an embodiment of the present application provides a structural deformation monitoring method based on RTK-GNSS, wherein at least two monitoring stations are arranged on the structure to be measured, and at least one monitoring station is selected as a reference station. The structural deformation monitoring method comprises:

[0007] Constructing double-difference pseudo-range observation equations and double-difference carrier phase observation equations between the reference station, the monitoring station and the GNSS satellites based on GNSS data between the reference station, the monitoring station and the two GNSS satellites;

[0008] Acquire a first initial position of the reference station and a second initial position of the monitoring station, and respectively acquire a first initial single-difference distance between the reference station and the two GNSS satellites and a second initial single-difference distance between the monitoring station and the two GNSS satellites;

[0009] Obtain a first coordinate offset of a first position observation value of the reference station at a current epoch relative to the first initial position, and calculate a second coordinate offset of the corresponding monitoring station at the current epoch relative to the second initial position based on the first coordinate offset, the first initial single difference distance, and the second initial single difference distance in combination with the double-difference pseudorange observation equation and the double-difference carrier phase observation equation;

[0010] The deformation amount of the structure to be measured is analyzed based on the second coordinate offset of each monitoring station.

[0011] In an optional solution of the first aspect, each of the reference stations forms a short baseline with one of the monitoring stations, and obtaining a first coordinate offset between a first position observation value of the reference station at a current epoch and the first initial position includes:

[0012] Obtaining a baseline deviation of a short baseline corresponding to the reference station;

[0013] The first coordinate offset is obtained based on the coordinate difference between the first position observation value of the reference station at the current epoch and the first initial position and the corresponding baseline deviation.

[0014] In an optional scheme of the first aspect, the calculating, based on the first coordinate offset, the first initial single difference distance, and the second initial single difference distance in combination with the double difference pseudorange observation equation and the double difference carrier phase observation equation, respectively, a second coordinate offset of the corresponding monitoring station at the current epoch relative to the second initial position includes:

[0015] Calculate the second coordinate offset of the corresponding monitoring station at the current epoch relative to the second initial position based on the Kalman filter system, and calculate the state vector of the monitoring station; wherein the state vector includes the position coordinates of the monitoring station at the current epoch and the ambiguity estimate;

[0016] A state vector for a next epoch is calculated based on a state transfer matrix, a system noise vector, and the state vector for the current epoch.

[0017] In an optional solution of the first aspect, before calculating the state vector of the next epoch based on the state transfer matrix, the system noise vector and the state vector of the current epoch, the method further includes:

[0018] Calculate an ambiguity subset for each epoch based on the least squares ambiguity decorrelation adjustment method, perform RATIO calculation on the ambiguities in the ambiguity subset, and select the ambiguity whose RATIO is greater than a preset threshold as the fixed ambiguity in the corresponding epoch;

[0019] The Kalman filter system is updated based on the fixed ambiguity, and the ambiguity fixed solution of the coordinate position of the monitoring station in each epoch is calculated based on the updated Kalman filter system.

[0020] In a second aspect, the embodiment of the present application further provides a structural deformation monitoring system based on RTK-GNSS, comprising:

[0021] A base station unit includes at least two monitoring stations disposed on the structure to be measured, wherein at least one monitoring station is a reference station;

[0022] A calculation unit, used for constructing a double-difference pseudo-range observation equation and a double-difference carrier phase observation equation between the reference station, the monitoring station and the GNSS satellites according to GNSS data between one of the reference stations, one of the monitoring stations and two GNSS satellites in the base station unit;

[0023] The calculation unit is further used to obtain a first initial position of the reference station, a second initial position of each of the monitoring stations, and respectively obtain a first initial single difference distance between the reference station and the two GNSS satellites and a second initial single difference distance between the monitoring station and the two GNSS satellites;

[0024] The calculation unit is further used to obtain a first coordinate offset of a first position observation value of the reference station at a current epoch relative to the first initial position, and calculate a second coordinate offset of the corresponding monitoring station at the current epoch relative to the second initial position based on the first coordinate offset, the first initial single difference distance and the second initial single difference distance in combination with the double difference pseudorange observation equation and the double difference carrier phase observation equation;

[0025] The deformation analysis unit is used to analyze the deformation amount of the structure to be measured according to the second coordinate offset of each monitoring station.

[0026] In an optional solution of the second aspect, each of the reference stations in the base station unit respectively forms a short baseline with one of the monitoring stations, and the calculation unit is further used to obtain a first coordinate offset between a first position observation value of the reference station at a current epoch and the first initial position, including:

[0027] Obtaining a baseline deviation of the corresponding short baseline of the reference station;

[0028] The first coordinate offset is obtained based on the coordinate difference between the first position observation value of the reference station at the current epoch and the first initial position and the corresponding baseline deviation.

[0029] In a third aspect, an embodiment of the present application further provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the method provided in the first aspect of the embodiment of the present application or any one of the implementation methods of the first aspect is implemented.

[0030] In a fourth aspect, the present application also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the method provided by the first aspect of the embodiment of the present application or any one of the implementations of the first aspect.

[0031] The beneficial effects brought about by the technical solutions provided by some embodiments of the present application include at least:

[0032] An RTK-GNSS-based structural deformation monitoring method provided in an embodiment of the present application establishes a short baseline between each reference station and each monitoring station, and uses the reference station as a mobile base station, taking into account the position deviation of the reference station. Even in the case of poor observation environment and partial obstruction of the base station by buildings, trees, etc., accurate observation of the monitoring station can be achieved. This overcomes the defect in the related art that GNSS cannot achieve accurate positioning when the observation environment is poor and the monitoring station signal is blocked. Compared with the related art, this method has the advantages of stable positioning and high reliability.

[0033] In addition, in the related art, the passage of vehicles and obstacles around them can cause signal blocking and frequent loss of lock, which in turn causes the ambiguity to be fixed to an incorrect integer value, making it impossible to stably output accurate positioning results. The present application, by considering the position deviation of the base station, can improve the ambiguity positioning rate based on the mobile base station RTK-GNSS method, and can more easily find the correct integer ambiguity. Compared with the related art, it can greatly improve the efficiency of calculating ambiguity under specific conditions, will not be affected by environmental factors, and can output accurate calculation results in real time, efficiently and stably under the corresponding environment.

[0034] Furthermore, the embodiment of the present application can also determine whether the structure to be tested has deformed based on the time series analysis of the coordinates of each monitoring station, and can perform deformation monitoring in real time and accurately without being affected by environmental changes, overcoming the defect that the deformation analysis results of some epochs are unstable due to environmental factors in related technologies. Even in complex environments, the deformation of the structure to be tested can be continuously monitored, and the deformation monitoring results are more stable and reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the present application or related technologies, the drawings required for use in the embodiments or related technical descriptions are briefly introduced below. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0036] Figure 1 It is a flow chart of a structural deformation monitoring method based on RTK-GNSS provided in an embodiment of the present application;

[0037] Figure 2 It is a flow chart of a structural deformation monitoring method based on RTK-GNSS provided in an embodiment of the present application;

[0038] Figure 3 is a structural schematic diagram of a structural deformation monitoring system based on RTK-GNSS provided in an embodiment of the present application;

[0039] Figure 4 It is a schematic diagram of the structure of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical solutions and advantages of this application clearer, the technical solutions in this application will be clearly and completely described below in conjunction with the drawings in this application. Obviously, the described embodiments are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0041] The terms "including" and "having" and any variations thereof in the specification and claims of the present application and the above drawings are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device including a series of steps or modules is not limited to the listed steps or modules, but may optionally include steps or modules that are not listed, or may optionally include other steps or modules that are inherent to these processes, methods, products or devices.

[0042] It should be noted that the terms "first\second" involved in the present application are only used to distinguish similar objects, and do not represent a specific order for the objects. It is understandable that "first\second" can be interchanged with a specific order or sequence where permitted. It should be understood that the objects distinguished by "first\second" can be interchanged where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those described or illustrated herein.

[0043] It can be understood that the RTK-GNSS-based structural deformation monitoring method provided in the embodiment of the present application can be applied to deformation monitoring of large buildings, especially bridges. Taking bridges as an example, base stations can be set up on the abutments, spans, and towers of the bridges. Specifically, the tower monitoring station reference station can be used as a mobile base station to establish a short baseline with other monitoring stations on the bridge, and the mobile base station RTK-GNSS method can be used to achieve relative positioning, so as to improve the availability of GNSS in bridge structure health monitoring applications when the observation environment is poor or the reference station fails and the monitoring baseline distance is long.

[0044] The present application is described in detail below with reference to specific embodiments.

[0045] Next, combine Figure 1-2 , introduces the structural deformation monitoring method based on RTK-GNSS provided in the embodiment of the present application. Figure 1-2 As shown, the structural deformation monitoring method based on RTK-GNSS includes the following steps:

[0046] S101, constructing double-difference pseudo-range observation equations and double-difference carrier phase observation equations between a reference station, a monitoring station and GNSS satellites based on GNSS data between a reference station, a monitoring station and two GNSS satellites.

[0047] It can be understood that at least two monitoring stations are arranged on the structure to be measured, at least one monitoring station is selected as a reference station, and each reference station forms a short baseline with a monitoring station.

[0048] It can be understood that multiple short baselines can use a common monitoring station as the reference station.

[0049] Specifically, under short baseline conditions, the double-difference model can be used to eliminate the satellite orbit, satellite and monitoring station clock offsets and hardware delays to a negligible level, greatly weakening the delays in the ionosphere and troposphere. The constructed double-difference pseudorange observation equation and double-difference carrier phase observation equation are shown below:

[0050]

[0051] in, is the DD operator; i and j are satellite numbers; 1 and 2 represent the monitoring station types, where 1 represents the reference station number and 2 represents the monitoring station number; ρ is the geometric distance between the satellite and the receiver; λ is the carrier phase wavelength; N is the integer phase ambiguity; ε is the measurement noise of the pseudorange observation; ξ is the phase multipath error of the carrier observation.

[0052] in, represents double-difference pseudorange; represents the double difference geometric distance between satellite i and satellite j and the reference station and monitoring station; Specifically, it is the measurement noise of pseudo-range observations between satellite i and satellite j and the reference station and monitoring station; represents double difference carrier phase; represents the integer phase ambiguity between satellite i and satellite j and the reference station and monitoring station; Specifically, it is the phase multipath error of the carrier observation between satellite i and satellite j and the reference station and monitoring station.

[0053] S102, obtaining a first initial position of the reference station and a second initial position of the monitoring station, and respectively obtaining a first initial single-difference distance between the reference station and two GNSS satellites and a second initial single-difference distance between the monitoring station and the two GNSS satellites.

[0054] Specifically, the coordinates of each monitoring station set on the structure to be measured are known quantities, that is, the first initial position (x 10 ,y 10 , z 10 ) and the corresponding second initial position of the monitoring station (x 20 ,y 20 , z 20 ), where 0 represents the initial position, which can be understood as the initial installation position of each monitoring station / reference station. The deformation at the corresponding position can be analyzed based on the displacement of the monitoring station relative to the corresponding installation position.

[0055] Specifically, the coordinate offset of the two stations relative to their initial positions is expressed as (δx 1 ,δy 1 ,δz 1 ) and (δx 2 ,δy 2 ,δz 2 ); The first initial single difference distance between the base station and two GNSS satellites can be expressed as The second initial single-difference distance between the monitoring station and the two GNSS satellites is expressed as Here, Δ is the single difference operator.

[0056] The double-difference pseudorange observation equation and the double-difference carrier phase observation equation in S101 can be expressed as:

[0057]

[0058]

[0059] in, The subscript u = 1 or 2, corresponding to the type of monitoring station, and the superscript s indicates the satellite. The direction cosines representing the one-way observation from the base station to the satellite, for example represents the direction cosine of the one-way observation from the monitoring station to satellite i, Represents the direction cosines of the one-way observation from the base station to satellite j.

[0060] It should be noted that in traditional positioning algorithms, the base station is often regarded as completely fixed, that is, the position coordinates of the base station are used as the fixed reference for positioning. However, in the deformation measurement scenarios of structures such as bridges, since the base station is arranged on the structure, the vibration of the structure will cause the base station to have a position deviation. The base station itself will also be affected by obstacles around the structure and signal obstruction caused by passing vehicles. Therefore, in this scenario, using the base station itself as a fixed reference will lead to a large positioning error.

[0061] The present application determines the first initial position of the base station and the second initial position of the monitoring station through step S102, and simultaneously considers the first initial single difference distance between the base station and the two GNSS satellites and the second initial single difference distance between the monitoring station and the two GNSS satellites. Although the use of the single difference distance will lead to an increase in the calculation complexity, the deviation of the base station relative to the initial position can be determined by calculating the single difference distance, thereby improving the measurement accuracy in the deformation measurement scenario of structures such as bridges, and avoiding the defect that the related technology cannot achieve positioning and deformation monitoring due to the influence of position deviation and signal shielding in the deformation measurement scenario of structures such as bridges.

[0062] S103, obtaining the first coordinate offset of the first position observation value of the reference station at the current epoch relative to the first initial position, and calculating the second coordinate offset of the corresponding monitoring station at the current epoch relative to the second initial position based on the first coordinate offset, the first initial single difference distance and the second initial single difference distance in combination with the double difference pseudorange observation equation and the double difference carrier phase observation equation.

[0063] It should be noted that, referring to the description of S102, since the relevant technology does not take into account the coordinate deviation of the base station itself and signal blocking issues, the relevant technology is not suitable for deformation measurement scenarios of structures such as bridges, that is, the relevant technology does not calculate the coordinate offset of the base station. Therefore, the present application eliminates the influence of the deformation measurement error caused by the position offset of the base station by calculating the coordinate offset of the base station, which is conducive to improving the calculation accuracy.

[0064] It can be understood that when the reference station position does not change, δx 1 ,δy 1 ,δz 1 Both are 0, that is, the first coordinate offset is 0.

[0065] Specifically, the coordinates of the reference station are known parameters, and the first coordinate offset is also a known parameter. It is necessary to solve the second coordinate offset of the monitoring station at the current epoch relative to the second initial position.

[0066] Based on the double-difference pseudorange observation equation and double-difference carrier phase observation equation in S101 and S102, we can obtain:

[0067]

[0068] Furthermore, the residual between the observed value and the true value of the pseudorange in the above formula is determined:

[0069] V = AX + L;

[0070]

[0071] Furthermore, the double differential pseudorange and carrier phase observations are expressed in matrix form, and the above equation is solved based on the least squares method to obtain:

[0072]

[0073] Among them, the residual equation is:

[0074] V T PV=0;

[0075] Among them, V is the residual matrix, P represents the identity matrix; A is the coefficient matrix; T represents the transposed matrix; It represents the least squares parameter estimate, including the baseline vector and the double difference, that is, the location coordinates of the monitoring station, X represents the second coordinate offset; L represents the difference between the observed value and the calculated value, as shown in the following formula:

[0076]

[0077] When the base station moves, the first coordinate offset is not 0, that is, the actual position coordinate of the base station is different from the preset first initial position (x 10 ,y 10 , z 10 ) has a coordinate difference δX 1 =(δx 1 ,δy 1 ,δz 1 ), the estimated coordinate offset of the monitoring station can be expressed as:

[0078] δX 2 =δX 1 +δΔX 12 ;

[0079] Among them, δΔX 12The baseline deviation is introduced by the reference station coordinate deviation. After the baseline deviation is introduced, the influence of the reference station coordinate deviation on the monitoring station can be expressed by the translation term and the baseline deviation.

[0080] Specifically, the difference between the observed value and the calculated value after the baseline deviation is introduced is as follows:

[0081]

[0082] The least squares parameter estimates after introducing the baseline bias are expressed as:

[0083]

[0084]

[0085] Among them, after the introduction of baseline deviation, the influence of the first coordinate deviation of the reference station on the estimated value of the second coordinate deviation of the monitoring station is:

[0086] It can be understood that the estimated value of the second coordinate deviation is added to the initial coordinates of the monitoring station to obtain the position coordinates of the monitoring station at the corresponding moment.

[0087] It should be noted that the baseline in the embodiment of the present application is established based on the reference station and the monitoring station. Therefore, the influence of the decreased accuracy caused by the coordinate deviation can be further eliminated by calculating the baseline deviation generated on the reference station side, which is beneficial to further improve the calculation accuracy and avoid the defect that the related technology does not take into account the decreased accuracy caused by the coordinate offset of the reference station.

[0088] Furthermore, through real-time baseline deviation compensation, the positioning error caused by the baseline deviation can be eliminated in real time, and the real-time and accurate output of the deformation monitoring results can be ensured.

[0089] In some embodiments, the second coordinate offset of the corresponding monitoring station at the current epoch relative to the second initial position can be calculated by the Kalman filter system to obtain the state vector of the monitoring station, wherein the state vector includes the position coordinates of the monitoring station at the current epoch and the ambiguity estimate.

[0090] Specifically, the state equation and observation equation can be shown as follows:

[0091] X k+1 =φ k+1，k X k +Fw k ;

[0092] L k =A K X k +V k ;

[0093] Among them, the state vector X k Contains the monitoring station coordinate parameters and the double-difference ambiguity estimate of epoch k; Φ k+1 , k is the state transfer matrix (i.e., the identity matrix): w k is the system noise vector (independent of the observation noise, with a mean of zero, which is the characteristic of Gaussian white noise); Fw k is the coefficient matrix of system noise; V k is the residual matrix. The floating solution is obtained by Kalman filter estimation.

[0094] Furthermore, the state vector of the next epoch can be calculated based on the state transfer matrix, the system noise vector and the state vector of the current epoch.

[0095] In some embodiments, before calculating the state vector of the next epoch based on the state transfer matrix, the system noise vector and the state vector of the current epoch, an ambiguity subset for each epoch can be calculated based on the least squares ambiguity decorrelation adjustment method, and the ambiguities in the ambiguity subset can be RATIO calculated, and the ambiguities with RATIO greater than a preset threshold are selected as fixed ambiguities in the corresponding epoch.

[0096] Exemplarily, the preset threshold may be set to 3.0.

[0097] Furthermore, the Kalman filter system is updated based on the fixed ambiguity, and the ambiguity fixed solution of the coordinate position of the monitoring station in each epoch is calculated based on the updated Kalman filter system.

[0098] S104, analyzing the deformation amount of the structure to be measured based on the second coordinate offset of each monitoring station.

[0099] Specifically, based on the above steps S101-S103, the least square parameter estimation value after the baseline deviation is introduced is subjected to Kalman filtering, so that the position deviation estimation value of the monitoring station at each moment can be obtained, and then the position coordinate time series of the monitoring station can be calculated.

[0100] Based on the modeling analysis of the monitoring station coordinate time series, the deformation amount, deformation direction, deformation rate, deformation cause analysis can be extracted, and the horizontal movement, settlement, level, inclination and curvature of the deformation can be analyzed to obtain the deformation analysis results of the monitoring station. The embodiments of the present application do not limit the form of the deformation analysis results.

[0101] In a preferred embodiment, refer to Figure 2 As shown in the flowchart, the RTK-GNSS-based structural deformation monitoring method provided in the embodiment of the present application may include the following steps:

[0102] S201, obtaining double-difference pseudorange observation values ​​and double-difference carrier phase observation values ​​in the corresponding epoch by using the observation equation of the short baseline formed between each group of reference stations and monitoring stations under the short baseline condition constructed in step S101.

[0103] S202, determining the initial position coordinates of the reference station and the monitoring station in the short baseline formed between each group of reference stations and monitoring stations.

[0104] Specifically, the initial position coordinates of the reference station and the monitoring station are known, which are the setting positions of the reference station and the monitoring station in the corresponding epoch.

[0105] S203, calculating a second coordinate offset of the monitoring station relative to the initial position coordinates according to the first coordinate offset of the reference station relative to the initial position coordinates.

[0106] Specifically, the base station of the present application is a mobile base station, that is, the position coordinates of the base station can change, thereby introducing a coordinate offset caused by the movement of the base station, that is, there is a coordinate difference between the actual position coordinates of the base station and the preset initial position coordinates, thereby correcting the coordinate offset of the monitoring station.

[0107] Specifically, in the process of calculating the coordinate offset of the monitoring station, it is necessary to fix the ambiguity and obtain a solution after the ambiguity is fixed. Specifically, a floating solution can be obtained through Kalman filtering estimation, and then the ambiguity can be searched and repaired according to the least squares ambiguity and decorrelation evaluation method to obtain the fixed ambiguity of the current epoch.

[0108] Specifically, in S203, based on the known coordinate offset of the reference station, the ambiguity of the current epoch, the double-difference pseudo-range observation value and the double-difference carrier phase observation value in the corresponding epoch, the known values ​​can be substituted into the pseudo-range observation equation and the carrier phase observation equation, and the coordinate offset of the monitoring station can be easily calculated.

[0109] Furthermore, the deformation amount of the structure to be measured can be analyzed according to the calculated coordinate offsets of the multiple monitoring stations.

[0110] It can be understood that the change in the coordinate offset of the corresponding monitoring station in multiple epochs can be cumulatively calculated based on the coordinate offset of the monitoring station measured in each short baseline, and the deformation of a single monitoring station can be analyzed by statistically analyzing the deformation-time change curve, thereby completing the analysis of the deformation and vibration characteristics of the monitoring points where each monitoring station is located; the overall deformation generated within a continuous distance can also be calculated by connecting multiple monitoring stations, and the deformation of the structure corresponding to the continuous distance can be analyzed. For example, if monitoring stations are set at both ends and the middle of a beam, it is easy to obtain the deformation state of the beam based on the coordinate offset analysis of the monitoring stations at both ends and the middle. The embodiments of the present application are not limited to this.

[0111] The structural deformation monitoring method based on RTK-GNSS provided in the embodiment of the present application uses the reference station as a mobile base station, and establishes a short baseline with the mobile base station and other monitoring stations on the structure (such as a bridge), and realizes relative positioning through the mobile base station RTK-GNSS method, thereby avoiding the defects of the related art that the GNSS signal is easily blocked in the case of poor observation environment, failure of the reference station, and long baseline, resulting in reduced observation quality and limited accuracy. The short baseline setting of the reference station and the monitoring station is conducive to improving the fuzzy positioning rate. By determining the coordinate offset of the mobile reference station and considering the baseline deviation, it is conducive to reducing the calculation amount of the fuzziness, and can improve the calculation efficiency of the fuzziness. Through the setting of multiple short baselines, the deformation and vibration characteristics of each monitoring point can be obtained, and the displacement and vibration amplitude of each monitoring point can be further estimated, which can effectively improve the estimation accuracy of the displacement and vibration amplitude, and the estimation accuracy can reach better than 4mm. The following is a system embodiment of the present application, which can be used to execute the method embodiment of the present application. For details not disclosed in the system embodiment of the present application, please refer to the method embodiment of the present application.

[0112] See next Figure 3 , is a schematic diagram of the structure of a RTK-GNSS-based structural deformation monitoring system provided by an exemplary embodiment of the present application. The system can be implemented as all or part of a terminal through software, hardware, or a combination of both, and can also be integrated on a server as an independent module. The RTK-GNSS-based structural deformation monitoring system in the embodiment of the present application can be applied to a terminal or a cloud. The system 30 includes a base station unit 310, a computing unit 320, and a deformation analysis unit 330, wherein:

[0113] The base station unit 310 includes at least two monitoring stations disposed on the structure to be measured, at least one of which is a reference station;

[0114] The calculation unit 320 is used to construct a double-difference pseudo-range observation equation and a double-difference carrier phase observation equation between the reference station, the monitoring station and the GNSS satellites according to the GNSS data between one of the reference stations, one of the monitoring stations and two GNSS satellites in the base station unit;

[0115] The calculation unit 320 is further used to obtain a first initial position of the reference station, a second initial position of each of the monitoring stations, and respectively obtain a first initial single difference distance between the reference station and the two GNSS satellites and a second initial single difference distance between the monitoring station and the two GNSS satellites;

[0116] The calculation unit 320 is further used to obtain a first coordinate offset of a first position observation value of the reference station at a current epoch relative to the first initial position, and calculate a second coordinate offset of the corresponding monitoring station at the current epoch relative to the second initial position based on the first coordinate offset, the first initial single difference distance and the second initial single difference distance in combination with the double difference pseudorange observation equation and the double difference carrier phase observation equation;

[0117] The deformation analysis unit 330 is used to analyze the deformation amount of the structure to be measured according to the second coordinate offset of each monitoring station.

[0118] In some embodiments, each of the reference stations in the above-mentioned base station unit 310 respectively forms a short baseline with one of the monitoring stations, and the calculation unit 320 is also used to obtain the first coordinate offset between the first position observation value of the reference station in the current epoch and the first initial position, which can be used to obtain the baseline deviation of the reference station in the corresponding short baseline, and obtain the first coordinate offset based on the coordinate difference between the first position observation value of the reference station in the current epoch and the first initial position and the corresponding baseline deviation.

[0119] It should be noted that the system 30 provided in the above embodiment only uses the division of the above functional modules as an example when executing the structural deformation monitoring method based on RTK-GNSS. In actual applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above. In addition, the system provided in the above embodiment and the embodiment of the structural deformation monitoring method based on RTK-GNSS belong to the same concept, and its implementation process is detailed in the method embodiment, which will not be repeated here.

[0120] An embodiment of the present application also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of any of the above-mentioned method embodiments when executing the program.

[0121] See also Figure 4 , which is a structural block diagram of an electronic device provided in an embodiment of the present application.

[0122] like Figure 4 As shown, the electronic device 400 includes: a processor 401 and a memory 402 .

[0123] In the embodiment of the present application, the processor 401 is the control center of the computer system, which can be a processor of a physical machine or a processor of a virtual machine. The processor 401 may include one or more processing cores, such as a 4-core processor, an 8-core processor, etc. The processor 401 may be implemented in at least one hardware form of DSP (Digital Signal Processing), FPGA (Field-Programmable Gate Array), and PLA (Programmable Logic Array).

[0124] The processor 401 may also include a main processor and a coprocessor. The main processor is a processor for processing data in the awake state, also called a CPU (Central Processing Unit); the coprocessor is a low-power processor for processing data in the standby state.

[0125] The memory 402 may include one or more computer-readable storage media, which may be non-transitory. The memory 402 may also include a high-speed random access memory, and a non-volatile memory, such as one or more disk storage devices, flash memory storage devices. In some embodiments of the present application, the non-transitory computer-readable storage medium in the memory 402 is used to store at least one instruction, which is used to be executed by the processor 401 to implement the method in the embodiment of the present application.

[0126] In some embodiments, the electronic device 400 further includes: a peripheral device interface 403 and at least one peripheral device 404. The processor 401, the memory 402 and the peripheral device interface 404 can be connected via a bus or a signal line. Each peripheral device 404 can be connected to the peripheral device interface 403 via a bus, a signal line or a circuit board. Specifically, the peripheral device 404 includes: a display screen, a camera and an audio circuit. The peripheral device interface 403 can be used to connect at least one peripheral device related to I / O (Input / Output) to the processor 401 and the memory 402.

[0127] In some embodiments of the present application, the processor 401, the memory 402, and the peripheral device interface 403 are integrated on the same chip or circuit board; in some other embodiments of the present application, any one or two of the processor 401, the memory 402, and the peripheral device interface 403 can be implemented on a separate chip or circuit board. This embodiment of the present application does not specifically limit this.

[0128] The electronic device structure block diagram shown in the embodiment of the present application does not constitute a limitation on the electronic device 400. The electronic device 400 may include more or fewer components than shown in the figure, or combine certain components, or adopt a different component arrangement.

[0129] The embodiment of the present application also provides a computer-readable storage medium, on which a computer program is stored, and when the program is executed by a processor, the steps of the method of any of the above embodiments are implemented. The computer-readable storage medium may include, but is not limited to, any type of disk, including a floppy disk, an optical disk, a DVD, a CD-ROM, a micro drive, and a magneto-optical disk, a ROM, a RAM, an EPROM, an EEPROM, a DRAM, a VRAM, a flash memory device, a magnetic card or an optical card, a nanosystem (including a molecular memory IC), or any type of medium or device suitable for storing instructions and / or data.

[0130] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, by hardware. Based on this understanding, the above technical solution can be essentially or in other words, the part that contributes to the relevant technology can be embodied in the form of a software product, which can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiment.

[0131] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A structural deformation monitoring method based on RTK-GNSS, characterized in that: At least two monitoring stations are arranged on the structure to be tested, and at least one monitoring station is selected as a reference station. The structural deformation monitoring method comprises: Constructing double-difference pseudo-range observation equations and double-difference carrier phase observation equations between the reference station, the monitoring station and the GNSS satellites based on GNSS data between the reference station, the monitoring station and the two GNSS satellites; Acquire a first initial position of the reference station and a second initial position of the monitoring station, and respectively acquire a first initial single-difference distance between the reference station and the two GNSS satellites and a second initial single-difference distance between the monitoring station and the two GNSS satellites; Obtain a first coordinate offset of a first position observation value of the reference station at a current epoch relative to the first initial position, and calculate a second coordinate offset of the corresponding monitoring station at the current epoch relative to the second initial position based on the first coordinate offset, the first initial single difference distance, and the second initial single difference distance in combination with the double-difference pseudorange observation equation and the double-difference carrier phase observation equation; The deformation amount of the structure to be measured is analyzed based on the second coordinate offset of each monitoring station.

2. The structural deformation monitoring method based on RTK-GNSS according to claim 1, characterized in that: Each of the reference stations forms a short baseline with one of the monitoring stations, and obtaining the first coordinate offset between the first position observation value of the reference station at the current epoch and the first initial position includes: Obtaining a baseline deviation of a short baseline corresponding to the reference station; The first coordinate offset is obtained based on the coordinate difference between the first position observation value of the reference station at the current epoch and the first initial position and the corresponding baseline deviation.

3. The structural deformation monitoring method based on RTK-GNSS according to claim 2 is characterized in that: The method of respectively calculating the second coordinate offset of the corresponding monitoring station at the current epoch relative to the second initial position based on the first coordinate offset, the first initial single difference distance and the second initial single difference distance in combination with the double difference pseudorange observation equation and the double difference carrier phase observation equation comprises: Calculate the second coordinate offset of the corresponding monitoring station at the current epoch relative to the second initial position based on the Kalman filter system, and calculate the state vector of the monitoring station; wherein the state vector includes the position coordinates of the monitoring station at the current epoch and the ambiguity estimate; A state vector for a next epoch is calculated based on a state transfer matrix, a system noise vector, and the state vector for the current epoch.

4. The structural deformation monitoring method based on RTK-GNSS according to claim 3 is characterized in that: Before calculating the state vector of the next epoch based on the state transfer matrix, the system noise vector and the state vector of the current epoch, the method further includes: Calculate an ambiguity subset for each epoch based on the least squares ambiguity decorrelation adjustment method, perform RATIO calculation on the ambiguities in the ambiguity subset, and select the ambiguity whose RATIO is greater than a preset threshold as the fixed ambiguity in the corresponding epoch; The Kalman filter system is updated based on the fixed ambiguity, and the ambiguity fixed solution of the coordinate position of the monitoring station in each epoch is calculated based on the updated Kalman filter system.

5. A structural deformation monitoring system based on RTK-GNSS, characterized in that: include: A base station unit includes at least two monitoring stations disposed on the structure to be measured, wherein at least one monitoring station is a reference station; A calculation unit, used for constructing a double-difference pseudo-range observation equation and a double-difference carrier phase observation equation between the reference station, the monitoring station and the GNSS satellites according to GNSS data between one of the reference stations, one of the monitoring stations and two GNSS satellites in the base station unit; The calculation unit is further used to obtain a first initial position of the reference station, a second initial position of each of the monitoring stations, and respectively obtain a first initial single difference distance between the reference station and the two GNSS satellites and a second initial single difference distance between the monitoring station and the two GNSS satellites; The calculation unit is further used to obtain a first coordinate offset of a first position observation value of the reference station at a current epoch relative to the first initial position, and calculate a second coordinate offset of the corresponding monitoring station at the current epoch relative to the second initial position based on the first coordinate offset, the first initial single difference distance and the second initial single difference distance in combination with the double difference pseudorange observation equation and the double difference carrier phase observation equation; The deformation analysis unit is used to analyze the deformation amount of the structure to be measured according to the second coordinate offset of each monitoring station.

6. The structural deformation monitoring system based on RTK-GNSS according to claim 5, characterized in that: Each of the reference stations in the base station unit respectively forms a short baseline with one of the monitoring stations, and the calculation unit is further used to obtain a first coordinate offset between a first position observation value of the reference station at a current epoch and the first initial position, including: Obtaining a baseline deviation of the corresponding short baseline of the reference station; The first coordinate offset is obtained based on the coordinate difference between the first position observation value of the reference station at the current epoch and the first initial position and the corresponding baseline deviation.

7. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the program, the steps of the method according to any one of claims 1 to 4 are implemented.

8. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 4 are implemented.

Images