High-precision rapid positioning method for pipe joint sinking process based on fusion of GPS and inertial navigation system

Abstract

The invention discloses a high-precision quick positioning method for a pipe joint sinking process based on fusion of a GPS (Global Positioning System) and an inertial navigation system, which comprises the following steps: constructing a dynamic monitoring system for the structural position and attitude of a moving object, the monitoring system comprising at least one GPS and inertial navigation system; processing observation data obtained by the GPS and inertial navigation system to obtain a high-precision continuously distributed data sequence; a pipe joint rigid body motion model and a coordinate dynamic conversion mode are constructed, and observation data of a GPS and observation data of an inertial navigation system are used for rapid calculation of underwater control point engineering coordinates. According to the invention, the underwater environment simulation driven by the monitoring data and the real-time visual intelligent control of the docking state are realized, and the microsecond-level high-precision synchronization of the observation data is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of tunnel water pipe installation, and particularly to a high-precision and fast positioning method for the pipe joint sinking process based on the fusion of GPS and inertial navigation systems. Background Art

[0002] For the underwater docking of the pipe joints of a immersed tube tunnel, high precision is required, and the installation of the docking section and the waterproof joint is technically difficult. On the other hand, during the sinking and installation process of the pipe joints of an immersed tube tunnel, due to the complexity of environmental factors such as wind, wave and current, the coordinate position and spatial attitude of the pipe joints are random and uncertain. In addition, after the structure sinks underwater, it is difficult to obtain coordinate data that meet the construction requirements by conventional measurement methods. The sinking process of the pipe joints depends to a certain extent on underwater detection operations, making the sinking and installation of the pipe joints in a complex flow field uncertain and posing great potential risks.

[0003] The pipe joints of an immersed tube tunnel are huge in volume and mass, and their towing and sinking movements in water have great inertia. In addition, the force and displacement of the towing system have hysteresis characteristics. Once the position of the docking control point is abnormal and deviated when approaching, it will be very difficult to correct immediately, resulting in excessive installation splicing errors or even technical failures. In engineering, it is necessary to obtain the high-precision coordinate values (relative position and attitude) of the underwater docking control points in a timely manner, so as to quickly feedback and pre-control the movement trend of the pipe joints, and achieve the purpose of intelligent feedback control and avoiding excessive deviation.

[0004] In summary, there is an urgent need to develop an underwater high-precision and fast positioning and real-time visualization intelligent measurement and control method for the pipe joint sinking process that does not rely on ground measurement reference points. Summary of the Invention

[0005] Aiming at the deficiencies in the prior art, the purpose of the present invention is to provide a high-precision and fast positioning method for the pipe joint sinking process based on the fusion of GPS and inertial navigation systems, realizing underwater environment simulation driven by monitoring data and real-time visualization intelligent control of the docking state, and achieving microsecond-level high-precision synchronization of observation data. To achieve the above object and other advantages of the present invention, there is provided a high-precision and fast positioning method for the pipe joint sinking process based on the fusion of GPS and inertial navigation systems, including:

[0006] Construct a dynamic monitoring system for the structural position and attitude of a moving object, where the monitoring system includes at least one GPS and inertial navigation system; install the GPS and inertial navigation systems at the set positions of the pipe joint at the same time, connect them to the data terminal control computer respectively, and set the time excitation, sampling time interval and synchronization accuracy on the two systems to achieve microsecond-level high-precision synchronization of observation data.

[0007] Process the observation data obtained by the GPS and inertial navigation system to obtain a high-precision continuously distributed data sequence; based on the fault tolerance and tolerance processing of the observation data, adopt the quadratic spline regression and Gaussian interpolation method to achieve the high-precision of massive data and the dynamic continuous reconstruction of sequence integrity.

[0008] Construct a rigid body motion model of the pipe section and a coordinate dynamic conversion method, ignoring the influence of the observation accuracy of the pipe section deformation, construct a rigid body motion model of the pipe section and a coordinate dynamic conversion method, and directly use the observation data of the GPS and inertial navigation systems for the rapid calculation of the engineering coordinates of the underwater control points. The observation data has been processed by high-precision and continuous reconstruction.

[0009] Connect the electronic nautical chart of the tunnel site area and the 3D design drawing of the pipe section to the database, and connect to the engineering coordinate system. Implement digital twin and real-time driving of the pipe section model using the VTK and PSM systems to achieve real-time visual intelligent control of the underwater environment simulation and docking state driven by monitoring data. Using data twin and pipe section model driving, the docking state of the pipe section is fed back to the construction in the form of relative coordinates and simulation videos in real time, realizing the visual intelligent control of the pipe section sinking and docking process.

[0010] i) Combine the GPS and inertial navigation system to achieve microsecond-level high-precision synchronization of position and attitude coordinate data; ii) Adopt the combination of spline regression and Gaussian interpolation to process random errors and missing data samples to obtain a high-precision continuously distributed data sequence; iii) Adopt the rigid body motion model of the pipe section and the coordinate conversion method to establish a rapid calculation method for the engineering coordinates of underwater control points; iv) Real-time visual intelligent control of the underwater environment simulation and docking state in the tunnel site area.

[0011] The present invention is applicable to the real-time visual monitoring of underwater installation of immersed tube tunnels. It fills the gaps in related technologies at home and abroad. Brief Description of the Drawings

[0012] Figure 1 It is a schematic structural diagram of the combination of the GPS and inertial navigation system for the high-precision and rapid positioning method of the pipe section sinking process based on the fusion of the GPS and inertial navigation system according to the present invention;

[0013] Figure 2 It is a schematic diagram of the data processing method for the high-precision and rapid positioning method of the pipe section sinking process based on the fusion of the GPS and inertial navigation system according to the present invention;

[0014] Figure 3 It is a schematic diagram of the pipe section coordinate system for the high-precision and rapid positioning method of the pipe section sinking process based on the fusion of the GPS and inertial navigation system according to the present invention;

[0015] Figure 4Schematic diagram of the layout of GPS monitoring points for tunnel segments in the high-precision and fast positioning method for the pipe-jacking sinking process based on the integration of GPS and inertial navigation system according to the present invention;

[0016] Figure 5 Schematic diagram of the position and coordinates of the control points on the end face of the pipe segment in the high-precision and fast positioning method for the pipe-jacking sinking process based on the integration of GPS and inertial navigation system according to the present invention;

[0017] Figure 6 Schematic diagram of the real-time visualization simulation structure of the pipe segment state in the high-precision and fast positioning method for the pipe-jacking sinking process based on the integration of GPS and inertial navigation system according to the present invention. Specific embodiments

[0018] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0019] Refer to Figure 1 , the high-precision and fast positioning method for the pipe-jacking sinking process based on the integration of GPS and inertial navigation system includes:

[0020] High-precision synchronous monitoring system: By combining GPS and inertial navigation system, a dynamic monitoring system for the structural position and attitude of moving objects independent of the ground measurement reference points is constructed. The system consists of 2 GPS receiving antennas and 1 inertial navigation system, which are respectively installed on the measurement tower after the pipe segment outfitting, and are respectively connected to the data terminal control computer. The time excitation, sampling time interval, and synchronous accuracy are set on the two systems to achieve microsecond-level high-precision synchronization of multi-sequence observation data. Through the coordination algorithm and error analysis and processing method of GNSS and inertial navigation synchronous data, the real-time dynamic coordinates of the pipe segment are determined. As Figure 1 shown.

[0021] High-precision continuity of data samples: Due to the influence of the accuracy of GPS and inertial navigation systems and environmental factors (such as bad weather, etc.), there will inevitably be systematic errors, accidental errors, and gross errors in GNSS and inertial navigation observation data, or accidental factors will cause data loss. These abnormal data must be scientifically processed. The present invention sets a fault tolerance tolerance mode to effectively filter out noise; then, for the observed data samples after noise cleaning, Gaussian interpolation is used to supplement the missing data that has been cleaned, and then spline regression is used for random error processing and reconstruction of the continuous distribution of the data sequence to obtain a high-precision continuously distributed data sequence. The calculation models and methods are as Figure 2 shown.

[0022] Underwater coordinate calculation based on observation data and rigid body motion model:

[0023] Ignoring the influence of the deformation of the pipe section on the monitoring results, a rigid body motion model of the pipe section and a coordinate dynamic conversion method are constructed, and the GNSS and inertial navigation observation data of the water surface measurement tower are used for the rapid calculation of the engineering coordinates of the underwater control points. Specifically, it includes: i) According to the size and geometric shape of the pipe section, a local coordinate system of the pipe section is established and underwater positioning control points are set, and the engineering coordinate system (engineering area coordinates based on WGS-84) is obtained through coordinate transformation. According to the real-time synchronous observation data of GPS and inertial navigation and the rigid body coordination calculation method of the pipe section, the dynamic coordinates (x i , y i , z i )(i = 1, 2, 3,..., n) of each positioning point at the same time step and the coordinate differences (Δx i , Δy i , Δz i ) with the fixed end are quickly calculated, as shown in Figures 3 - 5 .

[0024] Environmental simulation and real-time visualization of the docking state: The electronic nautical chart of the tunnel site area is modeled, the design CAD drawing of the pipe section and the design drawing of the underwater foundation trench are 3D modeled in the engineering coordinate system, connected to the database and the engineering coordinate system, the local environment of the engineering area is reconstructed and high-precision data is imported in real time, and the position, attitude, coordinate increment between docking points, etc. of the pipe section are displayed in real time on the computer interface; at the same time, the VTK and PSM systems are used to implement digital twin and real-time driving of the pipe section model, realizing real-time visualization, remote sharing and intelligent control of the underwater environment simulation and docking state driven by monitoring data. As shown in Figure 6 .

[0025] Example 1

[0026] 1. Monitoring system

[0027] Considering that the pipe section of the immersed tunnel is in a moving state in water during the sinking and installation process, its position and attitude change with time and are affected by the flow field and the towing traction system, and it is difficult to measure the high-precision position of the underwater positioning point. The present invention combines GPS (Beidou) and an inertial navigation system to jointly form a real-time monitoring system for the position and attitude during the sinking process of the pipe section. Two GNSS measurement antennas and one inertial navigation system are respectively installed on the front and rear measurement towers after the pipe section is outfitted, as shown in the figure.

[0028] The monitoring system simultaneously activates the GPS and inertial navigation systems through the satellite electronic clock to achieve high-frequency and high-precision synchronous data acquisition of the position coordinates of two monitoring points and the rotational displacements of the inertial system monitoring points around three orthogonal coordinate axes (i.e., the attitude of the pipe section).

[0029] System structure module composition and its functions:

[0030] (1) GPS: Responsible for reading data from the GPS measuring instrument and writing it into the local database.

[0031] (2) Inertial navigation system: Responsible for reading data from the inertial navigation system and writing it into the local database.

[0032] (3) Local database (SQL Server): Saves the measurement data that has been newly measured but not yet uploaded to the central database.

[0033] (4) Measurement agent: Responsible for reading data from the local database and uploading the measurement data to the central database. This agent accesses the remote measurement data service through the SOAP WebService protocol. If the network connection is unavailable, the agent program will periodically attempt to reconnect. Once the connection is available, the agent program will upload all the data saved in the local database.

[0034] (5) Measurement data service: Responsible for listening for and receiving the data uploaded from the measurement agent, and saving it to the central database. This service runs in the Tomcat Server and exposes interfaces through SOAP WebService.

[0035] (6) Central database (SQL Server): Responsible for saving all on-site measurement data.

[0036] 2. High-precision serialization processing of monitoring data

[0037] Measurement errors are divided into systematic errors, accidental errors, and gross errors.

[0038] Based on the error theory analysis, and according to the requirements of the pipe jacking sinking design specifications, the present invention constructs a method with fault tolerance and tolerance to filter out gross errors and accidental errors with a large order of magnitude. For the data missing in the original data sequence formed after the elimination of gross errors and the removal of accidental errors (or data missing caused by system failures or environmental factors during the acquisition process), a time series integrity test is performed on the number of data sequence samples, and then Gaussian interpolation is used to supplement the missing data. Then, spline regression is used for random error processing and the reconstruction of the continuous distribution of the data sequence to obtain a high-precision continuous distribution data sequence. The calculation models and methods are as Figure 6 shown.

[0039] Based on the finite sample space and the number of samples, the present invention uses the mean square error as a digital standard to measure the observation accuracy, also known as the "standard deviation" or "root mean square error" of the finite experiment. Since the true error is not easy to obtain, the correction number of the observed value obtained by the least squares method is used to replace the true error. The size of the mean square error is used to evaluate the accuracy of the observed value, and the calculation formula is as (1):

[0040]

[0041] 3. Calculation of the underwater positioning point coordinates of the pipe section

[0042] 1) Rigid body motion model of the pipe section

[0043] Ignoring the influence of the deformation of the pipe section on the monitoring results, a rigid body motion model of the pipe section and a coordinate dynamic conversion method are constructed. Through the rigid body displacement transfer mode, the GNSS and inertial navigation observation data of the water surface measurement tower are used for the rapid calculation of the engineering coordinates of the underwater control points.

[0044] 2) Centroid coordinates of the pipe segment

[0045] Considering the engineering independent coordinate system as (X s , Y s , Z s ), taking the centroid of the pipe segment as the coordinate origin, a pipe segment coordinate system is established as (X c , Y c , Z c ). As shown in Figure 3 .

[0046] According to the monitoring plan, 2 GPS measurement points and 1 attitude observation point are set on each pipe segment. As shown in Figure 4 .

[0047] The corresponding pipe segment coordinates are P1(X c , Y c , Z c ) and P2(X c , Y c , Z c ). The corresponding engineering coordinates (GPS measurement conversion results) are P1(X s , Y s , Z s ) and P2(X s , Y s , Z s ). The coordinate rotation based on the engineering coordinate system obtained by inertial navigation is (α, β, θ).

[0048] According to the coordinate conversion relationship:

[0049]

[0051] Then the engineering coordinate value of the centroid of the pipe segment:

[0052]

[0053] In the above formula, r ij (1, 2, 3) is the rotation matrix. Let R(α), R(β), and R(θ) be the rotation matrices for rotation about the (engineering coordinate) X-axis, Y-axis, and Z-axis respectively. The overall rotation matrix is as follows.

[0054]

[0055] Substituting the above formula into Equation (2) can obtain the centroid coordinates (X co , Y co , Z co ) of the pipe section corresponding to the engineering coordinates, which are used as the coordinates of the model-driven points.

[0056] 3) Calculation of coordinates of specific points on the pipe joint section

[0057] The control points on the pipe section end face are as Figure 5 shown.

[0058] Assume that the nominal dimensions of the pipe section are [L, D, h] (for non-rectangular planar pipe joints, it can be calculated as a prism with 4 corner points). The coordinate values of each control point corresponding to the pipe section coordinate system are k1(L / 2, D / 2, 0), k2(L / 2, 0, h / 2), k3(L / 2, -D / 2, 0), and k4(L / 2, 0, -h / 2) respectively.

[0059] Taking the (X co , Y co , Z co ) obtained from the above calculation as the coordinate translation value, the coordinate values of each control point corresponding to the engineering coordinate system can be calculated respectively by the following formula.

[0060]

[0061] In Equation (5), corresponding to the same sampling time, the calculation method and result of the rotation matrix remain unchanged, and the corresponding coordinate origin of the pipe section coordinate system remains unchanged (dynamic coordinate system - changing with the sampling time).

[0062] 4. Environmental simulation

[0063] 1) 3D modeling of drawing materials

[0064] Configure the 3D digital model in the PSM file mode. 3D model the environmental-related graphic and text materials such as the immersed tube structure, riverbed, and surrounding buildings and integrate them into the engineering coordinate system. Include: i) Design graphic data such as the floating transportation route design drawing around the tunnel site, the CAD drawing of the immersed tube section structure design, etc., and the construction drawings of the foundation trench and sinking control design; ii) Construction process and environmental-related data such as electronic nautical charts and scene photography images; iii) Pipe section position and status-related data such as GPS monitoring data and inertial navigation data.

[0065] 2) 3D graphic rendering

[0066] Build a unified 3D simulation graph based on the VTK third-party library. The external application module organizes the three-dimensional data into a data structure recognizable by the rendering engine according to the requirements of the rendering engine, and then transfers it to the rendering engine; the rendering engine calls the device management module as needed; finally, the virtual device that encapsulates hardware APIs such as DirectX and OpenGL draws the three-dimensional graph on the screen.

[0067] Real-time visualization of the docking state

[0068] Model the electronic nautical chart in the tunnel site area, 3D model the CAD drawings of the pipe joint design and the underwater foundation trench design drawings in the engineering coordinate system, access the database and connect to the engineering coordinate system, reconstruct the local environment of the engineering area and import high-precision data in real time, and the computer interface displays the position, attitude, and coordinate increment between docking points of the pipe joint in real time; at the same time, implement digital twin and real-time driving of the pipe joint model using the windowsForm system to achieve underwater environment simulation driven by monitoring data and real-time visualization, remote sharing, and intelligent control of the docking state.

[0069] 1) Composition of the subroutine

[0070] The visualization module is an independent executable application program, which consists of the following subroutines.

[0071] (1) Software interface: The main interface of the application program, based on Windows Form technology.

[0072] (2) Model management and import: Establish an extensible model management system and import function implementation, and configure model information in detail based on externally configurable psm files.

[0073] (3) Graphics rendering module: Quickly and efficiently realizing the rendering of 3D models is one of the key modules of the whole program, built based on the VTK third-party library.

[0074] (4) Data acquisition module integration and model driving: This sub-module is the core of the whole program and also the data source for data analysis and construction guidance. This module will directly access the real-time database of the immersed tube.

[0075] (5) Real-time data generation: This sub-module is based on the data acquisition module and can dynamically output construction-related data to guide construction. It is one of the key modules of the system.

[0076] (6) Relationship diagram between each module of the system: As Figure 6 shown.

[0077] 2) Model management and import

[0078] The establishment of a 3D model of the sinking site will greatly improve the visualization of the floating and sinking process. To enhance the authenticity of visualization, not only the actual monitored immersed tube model needs to be established, but also related tower racks, cables, dry docks, foundation trenches, and surrounding environmental facilities are involved.

[0079] However, if the relevant model information is constructed in the application program, the coupling between the directly imported application program and the model information will be greatly improved, and thus the application program will not be able to achieve extensibility. Therefore, how to reduce the coupling between the core code of the application program and the model is a prerequisite for software extensibility. Of course, the extensibility of the application program to the model will greatly increase the possibility of the software being applied to other projects.

[0080] 3) Integration of data acquisition module and model drive

[0081] When the system is running in the real-time monitoring mode, the data acquisition module will monitor the immersed tube database every 100 ms (the time interval density set by the program). Once new data is generated, it will notify the system and transfer the latest data to the system. When the system is running in the playback monitoring model, the data acquisition model will not actively notify the system, but the system will query the immersed tube database in real time according to the playback time specified by the current user and obtain relevant information. As Figure 6 shown.

[0082] The number of devices and the processing scale described here are used to simplify the description of the present invention. The application, modification, and variation of the present invention are obvious to those skilled in the art. Although the implementation embodiments of the present invention have been disclosed above, it is not limited to the applications listed in the specification and the implementation manners. It can be fully applied to various fields suitable for the present invention. For those familiar with the field, additional modifications can be easily achieved. Therefore, without departing from the general concept defined by the claims and the equivalent scope, the present invention is not limited to specific details and the illustrations shown and described here.

Claims

1. A high-precision and fast positioning method for the pipe-joint sinking process based on the fusion of GPS and inertial navigation systems, characterized in that Including: Construct a dynamic monitoring system for the structural position and attitude of a moving object, where the monitoring system includes at least one GPS and inertial navigation system; Process the observation data obtained by the GPS and inertial navigation systems to obtain a high-precision continuously distributed data sequence; Construct a rigid body motion model of the pipe section and a coordinate dynamic conversion method, and use the observation data of the GPS and the inertial navigation system for the rapid calculation of the engineering coordinates of underwater control points; Connect the electronic nautical chart of the tunnel site area and the 3D design drawing of the pipe section to the database, and connect to the engineering coordinate system. Implement digital twin and real-time driving of the pipe section model using the VTK and PSM systems to achieve real-time visual intelligent control of the underwater environment simulation and docking state driven by monitoring data.

2. The high-precision and fast positioning method for the pipe joint sinking process based on the fusion of GPS and inertial navigation system according to claim 1, characterized in that The measurement tower after the pipe section outfitting, where the GPS and inertial navigation systems are respectively installed on the measurement tower, and the GPS and inertial navigation systems are respectively connected to the data terminal control computer. Set the time excitation, sampling interval, and synchronization accuracy on the two systems, and determine the real-time dynamic coordinates of the pipe section through the coordination algorithm and error analysis and processing method for synchronizing data between the GPS and inertial navigation systems.

3. The high-precision and fast positioning method for the pipe-jacking sinking process based on the fusion of GPS and inertial navigation system according to claim 1, characterized in that, The processing of the observation data specifically refers to performing signal-to-noise cleaning on the observation data, then using Gaussian interpolation to supplement the missing data that has been cleaned, and then performing random error processing and reconstruction of the continuous distribution of the data sequence through spline regression to obtain a high-precision continuously distributed data sequence.

4. The high-precision and fast positioning method for the pipe joint sinking process based on the fusion of GPS and inertial navigation system according to claim 1, characterized in that, The use of the observation data of the GPS and the inertial navigation system for the rapid calculation of the engineering coordinates of underwater control points specifically is: Establish a local coordinate system of the pipe section and set underwater positioning control points according to the pipe section size and geometric shape; Obtain the engineering coordinate system through coordinate transformation; According to the real-time synchronous observation data of the GPS and inertial navigation system and the rigid body coordination calculation method of the pipe section, quickly calculate the dynamic coordinates of each positioning point at the same time step and the coordinate difference between this pipe section and other fixed ends.

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