Underground pipeline dead reckoning method and computer equipment based on start-end point correction and forward and reverse information reuse

Abstract

The underground pipeline dead reckoning method and computer equipment based on start and end point correction and forward and reverse information reuse belongs to the field of pipeline inertial positioning instrument surveying and positioning technology, and solves the problems of low short-distance measurement accuracy and large amount of calculation for underground pipeline positioning. The method of the present invention includes: binding the start and end point coordinates, and completing the initial alignment of the pipeline inertial positioning instrument, obtaining the MIMU gyroscope data in real time and substituting it into the quaternion differential square, using the fourth-order Runge-Kutta method to solve and obtain the real-time attitude quaternion; then, the mileage information output by the odometer measurement under the carrier system is converted into the speed information in the navigation coordinate system through the attitude quaternion and the trajectory position information is obtained by integral iteration, and then the position information of the forward and reverse dead reckoning is corrected respectively by constructing a correction matrix, and finally the corrected forward and reverse trajectories are merged and averaged. The present invention is suitable for high-precision surveying and positioning of underground pipelines.

Description

Technical Field

[0001] The present application relates to the technical field of surveying and positioning of pipeline inertial positioning instruments, and in particular to a method and computer equipment for dead reckoning of underground pipelines based on start and end point correction and forward and reverse information multiplexing. Background Art

[0002] Urban underground pipelines are the infrastructure of urban planning. The pipeline network buried deep underground in the city is widely used in water supply and drainage, oil and gas transportation, communication cable transmission, etc. The precise mapping of the location information of urban underground pipelines and the construction of their database are important components of smart city construction and important basic information for urban planning management.

[0003] Inertial measurement equipment plays an irreplaceable role in underground pipeline surveying and mapping, cleaning and maintenance of oil and gas pipelines, and location and detection of pipeline fault points. In recent years, pipeline inertial positioning instruments based on inertial technology have been widely used to obtain the direction, spatial position, ancillary facilities and related attribute information of trenchless underground pipelines, compile underground pipeline maps, and establish underground pipeline databases.

[0004] The promotion and application of high-precision inertial-level and tactical-level inertial measurement units in small-diameter pipelines are limited due to factors such as high cost and relatively large size. Micro-electromechanical systems have received widespread attention and application in urban underground pipeline mapping and positioning due to their small size, light weight and low cost. Pipeline inertial locators based on inertial technology generally use micro-electromechanical inertial measurement units as their core measurement sensors.

[0005] The dead reckoning method based on micro-electromechanical inertial measurement unit has a certain measurement accuracy in the short-distance underground pipeline positioning measurement. However, due to the limitations of the mathematical model of the dead reckoning method, its measurement error increases with the increase of measurement mileage. At the same time, the initial alignment accuracy of the pipeline inertial locator based on micro-electromechanical inertial measurement unit is not high, which makes it difficult to meet the needs of high-precision underground pipeline mapping and positioning.

[0006] In previous literature, the error correction method of combined navigation is often used for the positioning and measurement of trenchless underground pipelines. For example, in the Chinese patent document CN109974697A published on July 5, 2019, a high-precision surveying and mapping method based on an inertial system is disclosed. This method uses the Kalman filter method to measure and estimate the odometer and inertial navigation errors, and combines the preset magnetic punctuation points outside the pipeline for high-precision positioning to achieve beneficial measurement results. In published articles, such as the "Feasibility Study on the In-Diameter Detection and Positioning Scheme of Small-Diameter Pipelines Using MEMS Inertial Navigation" by Niu Xiaoji, Kuang Jian, and Chen Qijin in Volume 29, Issue 1 of the Journal of Sensor Technology, STIM300 was used to verify the underground pipeline positioning method based on inverse smoothing Kalman filtering and motion constraints. The measurement accuracy for pipelines with a length of 2 km can reach 10 -3 Although the above methods have achieved beneficial measurement results, the Kalman filter architecture increases the amount of calculation, and in order to achieve the ideal positioning measurement accuracy, the Kalman filter parameters need to be adjusted in time for different measurement environments. At the same time, the above methods have relatively large amount of calculation and low short-distance positioning accuracy, especially because: the filtering method requires a certain amount of time for the estimation error to converge, the short distance time is short, and the estimation accuracy is not high; the filtering method requires relatively accurate external measurement information. If the external measurement information is inaccurate, the estimation effect is very poor, resulting in low short-distance measurement accuracy. Summary of the invention

[0007] The purpose of the present invention is to solve the problems of low short-distance measurement accuracy and large amount of calculation in the existing technology for underground pipeline positioning, and to provide an underground pipeline dead reckoning method and computer equipment based on start and end point correction and forward and reverse information multiplexing.

[0008] The present invention is implemented by the following technical solutions. On one hand, the present invention provides an underground pipeline dead reckoning method based on start and end point correction and forward and reverse information multiplexing, the method comprising:

[0009] Step 1: Bind the starting and ending position information of the pipeline into the pipeline inertial positioning instrument;

[0010] Step 2: Collect MIMU data using the pipeline inertial positioning instrument, and construct an initial attitude matrix according to the MIMU data;

[0011] Step 3, converting the initial posture matrix into an initial quaternion and normalizing the initial quaternion;

[0012] Step 4: Obtain MIMU gyroscope data, substitute the MIMU gyroscope data into the quaternion differential equation, and use the fourth-order Runge-Kutta method to solve the quaternion differential equation to obtain an updated attitude quaternion;

[0013] Step 5: Using the updated attitude quaternion, convert the odometer measurement value in the carrier system into speed information in the navigation coordinate system;

[0014] Step 6: Obtain trajectory position information by using the velocity information in the navigation coordinate system and the iterative summation of the sampling interval time integral;

[0015] Step 7: construct a correction transformation matrix according to the starting and ending position information of the pipeline and the starting and ending coordinates in the trajectory position information, complete the forward solution trajectory correction, and obtain the forward solution trajectory data;

[0016] Step 8: Keep the heading of the pipeline inertial locator unchanged, make the pipeline inertial locator move in reverse from the end position to the starting position, repeat steps 1 to 7 to obtain the trajectory information after reverse solution correction, and obtain the trajectory data of reverse solution;

[0017] Step 9: sum and average the trajectory data obtained by the forward solution and the trajectory data obtained by the reverse solution at corresponding positions to obtain corrected trajectory information.

[0018] Furthermore, in step 2, the method of constructing the initial posture matrix is ​​specifically as follows:

[0019] The initial matrix is ​​obtained by using the formula to construct the initial posture matrix. The formula for obtaining the initial matrix is:

[0020]

[0021] Among them, C ij (i=1,2,3;j=1,2,3) represents the attitude matrix The elements in f bi (i=x, y, z) represents the measurement output value of the MIMU three-axis accelerometer, and g represents the local gravity acceleration value.

[0022] Furthermore, in step 3, the initial posture matrix is ​​converted into an initial quaternion, specifically: the initial posture matrix is ​​converted into an initial quaternion using a conversion formula, and the conversion formula is:

[0023]

[0024] Among them, C ij (i=1,2,3;j=1,2,3) represents the attitude matrix The elements in is the initial attitude quaternion.

[0025] Furthermore, in step 3, the normalizing the initial quaternion is specifically: using a normalization formula to normalize the initial quaternion, and the normalization formula is:

[0026]

[0027] Among them, q0 represents the normalized initial attitude quaternion.

[0028] Furthermore, step 4 specifically includes:

[0029] Step 4.1, obtain MIMU gyroscope data, and substitute the MIMU gyroscope data into the quaternion differential equation, the quaternion differential equation is:

[0030]

[0031] in, represents the projection of the rotation angular rate of the carrier system relative to the navigation system on the x-axis, y-axis and z-axis of the carrier system, q 0i (i=0,1,2,3) represents the elements in the normalized initial attitude quaternion q0, The derivative of the attitude quaternion expressed in projected form;

[0032] Step 4.2: Solve the quaternion differential equation using the fourth-order Runge-Kutta method to obtain

[0033]

[0034]

[0035]

[0036] Step 4.3: Obtain the updated attitude quaternion using the update formula, the update formula is:

[0037]

[0038] Among them, Ω i (i=1,2,3) represents the antisymmetric matrix formed by the sampling output of three MIMU gyroscopes, T is the sampling time, and q is the updated attitude quaternion.

[0039] Furthermore, step 5 specifically includes:

[0040] Step 5.1: Using the updated attitude quaternion, obtain the attitude matrix from the carrier system to the navigation system:

[0041]

[0042] Step 5.2: Use the attitude matrix of the carrier system to the navigation system Get the speed information in the navigation coordinate system:

[0043]

[0044] Among them, dS is the mileage increment information output by the odometer, and T is the odometer output sampling interval.

[0045] Furthermore, step 6 is specifically as follows:

[0046] Using the speed information v in the navigation coordinate system n , the trajectory position information is obtained by integrating and iterating the sampling interval time T:

[0047]

[0048] Among them, v i (i=E,N,U) represents the eastward, northward and celestial velocity information in the Cartesian coordinate system.

[0049] Furthermore, it specifically includes:

[0050] Step 7.1: construct a correction transformation matrix according to the pipeline start and end position information and the start and end coordinates in the trajectory position information, wherein the start and end coordinates include the three-dimensional coordinates of the starting point and the three-dimensional coordinates of the end point. The specific formula is as follows:

[0051]

[0052]

[0053]

[0054]

[0055]

[0056]

[0057]

[0058] Among them, x start y start z start is the three-dimensional coordinate of the starting point, x end y end z end is the three-dimensional coordinate of the end point, x′ end y′ end z′ end is the three-dimensional coordinate of the dead reckoning endpoint, K1 and K2 are the horizontal and height scale transformation factors, ψ1-ψ2 and ψ3-ψ4 are the horizontal azimuth error and height azimuth error, respectively. is the correction matrix;

[0059] Step 7.2: Use the correction matrix to correct the trajectory information and obtain the trajectory data of the forward solution:

[0060]

[0061] Furthermore, in step 9, the method for obtaining the corrected trajectory information is specifically as follows:

[0062] The corrected trajectory information is obtained by using the summation and averaging formula, which is:

[0063]

[0064] Among them, x, y, z represent the corrected trajectory information, x″1, y″1, z″1 represent the trajectory data of the forward solution, and x″2, y″2, z″2 represent the trajectory data of the reverse solution.

[0065] On the other hand, the present invention provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and when the processor runs the computer program stored in the memory, the method for dead reckoning of underground pipelines based on start and end point correction and forward and reverse information multiplexing as described above is executed.

[0066] Beneficial effects of the present invention:

[0067] Aiming at the problem of high-precision positioning and measurement of short-distance underground pipelines, the present invention proposes an underground pipeline dead reckoning method based on start-end point correction and forward and reverse information multiplexing.

[0068] First, based on the dead reckoning algorithm, the present invention aims at the known starting and ending position information of short-distance underground pipelines in actual engineering, and corrects the position information of forward and reverse dead reckoning respectively by constructing a correction matrix, and finally fuses and averages the corrected forward and reverse trajectories to achieve high-precision mapping and positioning of underground pipelines. Since there are cumulative errors in the dead reckoning trajectory, the forward and reverse correction is a correction of the trajectory, and its purpose is to improve the trajectory accuracy, and the fusion and average of the forward and reverse trajectories is a correction based on the first correction trajectory, thereby improving the positioning accuracy of the underground pipeline;

[0069] Secondly, the error correction process requires less computation than the filtering estimation method in the prior art;

[0070] Finally, there is no need to adjust the parameters, and the trajectory can be corrected by only knowing the coordinates of the starting and ending points, which solves the problem in the prior art that the parameters need to be adjusted according to the pipeline environment, resulting in low environmental adaptability of the method.

[0071] In the high-precision positioning and measurement of short-distance underground pipelines, the present invention constructs a correction matrix to correct the position information of forward and reverse dead reckoning respectively, and finally fuses and averages the corrected forward and reverse trajectories, thereby greatly improving the underground pipeline mapping and positioning accuracy.

[0072] The invention is suitable for high-precision mapping and positioning of underground pipelines. BRIEF DESCRIPTION OF THE DRAWINGS

[0073] In order to more clearly illustrate the technical solution of the present application, the drawings required for use in the embodiments are briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0074] Figure 1 It is a comparison diagram of the real trajectory, dead reckoning, end point correction, start and end point correction and information multiplexing trajectory of the present invention;

[0075] Figure 2 It is a graph showing the start and end point correction and information multiplexing error of the present invention. DETAILED DESCRIPTION

[0076] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0077] Embodiment 1: A method for dead reckoning of underground pipelines based on start and end point correction and forward and reverse information multiplexing, the method comprising:

[0078] Step 1: Bind the starting and ending position information of the pipeline into the pipeline inertial positioning instrument;

[0079] Step 2: Collect MIMU data using the pipeline inertial positioning instrument, and construct an initial attitude matrix according to the MIMU data;

[0080] It should be noted that this step 2 is to collect static MIMU data for a period of time to complete the initial alignment and construct the initial posture matrix.

[0081] Step 3, converting the initial posture matrix into an initial quaternion and normalizing the initial quaternion;

[0082] Step 4: Obtain MIMU gyroscope data, substitute the MIMU gyroscope data into the quaternion differential equation, and use the fourth-order Runge-Kutta method to solve the quaternion differential equation to obtain an updated attitude quaternion;

[0083] Step 5: Using the updated attitude quaternion, convert the odometer measurement value in the carrier system into speed information in the navigation coordinate system;

[0084] Step 6: Obtain trajectory position information by using the velocity information in the navigation coordinate system and the iterative summation of the sampling interval time integral;

[0085] Step 7: construct a correction transformation matrix according to the starting and ending position information of the pipeline and the starting and ending coordinates in the trajectory position information, complete the forward solution trajectory correction, and obtain the forward solution trajectory data;

[0086] Step 8: Keep the heading of the pipeline inertial locator unchanged, make the pipeline inertial locator move in reverse from the end position to the starting position, repeat steps 1 to 7 to obtain the trajectory information after reverse solution correction, and obtain the trajectory data of reverse solution;

[0087] Step 9: sum and average the trajectory data obtained by the forward solution and the trajectory data obtained by the reverse solution at corresponding positions to obtain corrected trajectory information.

[0088] This embodiment, in order to solve the problem of high-precision positioning and measurement of short-distance underground pipelines, proposes a method for underground pipeline dead reckoning based on start-end point correction and forward and reverse information reuse. Based on the dead reckoning algorithm, this embodiment, in order to solve the problem of high-precision positioning and measurement of short-distance underground pipelines in actual engineering, constructs a correction matrix to correct the position information of forward and reverse dead reckoning respectively, and finally fuses and averages the corrected forward and reverse trajectories to achieve high-precision mapping and positioning of underground pipelines.

[0089] There are cumulative errors in the dead reckoning trajectory. The forward and reverse corrections are corrections to the trajectory, and their purpose is to improve the trajectory accuracy. The forward and reverse trajectory fusion average is a second correction based on the first correction trajectory.

[0090] Implementation method 2: This implementation method further limits the underground pipeline dead reckoning method based on start and end point correction and forward and reverse information multiplexing described in implementation method 1. In this implementation method, the method of constructing the initial attitude matrix in step 2 is further limited, specifically:

[0091] The initial matrix is ​​obtained by using the formula to construct the initial posture matrix. The formula for obtaining the initial matrix is:

[0092]

[0093] Among them, C ij (i=1,2,3;j=1,2,3) represents the attitude matrix The elements in f bi(i=x, y, z) represents the measurement output value of the MIMU three-axis accelerometer, and g represents the local gravity acceleration value.

[0094] This embodiment provides a specific construction method and calculation formula for the initial posture matrix to achieve high-precision mapping and positioning of underground pipelines.

[0095] Implementation method three, this implementation method is a further limitation of the underground pipeline dead reckoning method based on start and end point correction and forward and reverse information multiplexing described in implementation method one. In this implementation method, in step 3, the initial attitude matrix is ​​converted into an initial quaternion, which is further limited as follows:

[0096] The initial posture matrix is ​​converted into an initial quaternion using a conversion formula, and the conversion formula is:

[0097]

[0098] Among them, C ij (i=1,2,3;j=1,2,3) represents the attitude matrix The elements in is the initial attitude quaternion.

[0099] This embodiment provides a specific conversion method and calculation formula for converting the initial posture matrix into an initial quaternion, so as to achieve high-precision mapping and positioning of underground pipelines.

[0100] Implementation method 4: This implementation method further limits the underground pipeline dead reckoning method based on start and end point correction and forward and reverse information multiplexing described in implementation method 1. In this implementation method, the normalization of the initial quaternion in step 3 is further limited as follows:

[0101] The initial quaternion is normalized using a normalization formula, and the normalization formula is:

[0102]

[0103] Among them, q0 represents the normalized initial attitude quaternion.

[0104] This implementation provides a specific normalization method and calculation formula for normalizing the initial quaternion to achieve high-precision mapping and positioning of underground pipelines.

[0105] Implementation mode 5: This implementation mode further limits the underground pipeline dead reckoning method based on start and end point correction and forward and reverse information multiplexing described in implementation mode 1. In this implementation mode, step 4 is further limited, specifically including:

[0106] Step 4.1, obtain MIMU gyroscope data, and substitute the MIMU gyroscope data into the quaternion differential equation, the quaternion differential equation is:

[0107]

[0108] in, represents the projection of the rotation angular rate of the carrier system relative to the navigation system on the x-axis, y-axis and z-axis of the carrier system, q 0i (i=0,1,2,3) represents the elements in the normalized initial attitude quaternion q0, The derivative of the attitude quaternion expressed in projected form;

[0109] Step 4.2: Solve the quaternion differential equation using the fourth-order Runge-Kutta method to obtain

[0110]

[0111]

[0112]

[0113] Step 4.3: Obtain the updated attitude quaternion using the update formula, the update formula is:

[0114]

[0115] Among them, Ω i (i=1,2,3) represents the antisymmetric matrix formed by the sampling output of three MIMU gyroscopes, T is the sampling time, and q is the updated attitude quaternion.

[0116] This implementation provides a specific updating method and related calculation formulas for updating attitude quaternions to achieve high-precision mapping and positioning of underground pipelines.

[0117] Implementation method 6: This implementation method further limits the underground pipeline dead reckoning method based on start and end point correction and forward and reverse information multiplexing described in implementation method 1. In this implementation method, step 5 is further limited, specifically including:

[0118] Step 5.1: Using the updated attitude quaternion, obtain the attitude matrix from the carrier system to the navigation system:

[0119]

[0120] Step 5.2: Use the attitude matrix of the carrier system to the navigation system Get the speed information in the navigation coordinate system:

[0121]

[0122] Among them, dS is the mileage increment information output by the odometer, and T is the odometer output sampling interval.

[0123] This embodiment provides a specific method for obtaining speed information in a navigation coordinate system and related calculation formulas to achieve high-precision mapping and positioning of underground pipelines.

[0124] Embodiment 7: This embodiment further limits the underground pipeline dead reckoning method based on start and end point correction and forward and reverse information multiplexing described in embodiment 1. In this embodiment, step 6 is further limited as follows:

[0125] Using the speed information v in the navigation coordinate system n , the trajectory position information is obtained by integrating and iterating the sampling interval time T:

[0126]

[0127] Among them, v i (i=E,N,U) represents the eastward, northward and celestial velocity information in the Cartesian coordinate system.

[0128] This embodiment provides a specific method for obtaining trajectory position information and related calculation formulas to achieve high-precision mapping and positioning of underground pipelines.

[0129] Embodiment 8: This embodiment further limits the underground pipeline dead reckoning method based on start and end point correction and forward and reverse information multiplexing described in embodiment 1. In this embodiment, step 7 is further limited, specifically including:

[0130] Step 7.1: construct a correction transformation matrix according to the pipeline start and end position information and the start and end coordinates in the trajectory position information, wherein the start and end coordinates include the three-dimensional coordinates of the starting point and the three-dimensional coordinates of the end point. The specific formula is as follows:

[0131]

[0132]

[0133]

[0134]

[0135]

[0136]

[0137]

[0138] Among them, x start ,y start , z start is the three-dimensional coordinate of the starting point, x end ,y end , z end is the three-dimensional coordinate of the end point, x′ end , y' end , z' end is the three-dimensional coordinate of the dead reckoning endpoint, K1 and K2 are the horizontal and height scale transformation factors, ψ1-ψ2 and ψ3-ψ4 are the horizontal azimuth error and height azimuth error, respectively. is the correction matrix;

[0139] Step 7.2: Use the correction matrix to correct the trajectory information and obtain the trajectory data of the forward solution:

[0140]

[0141] This embodiment provides a specific method for acquiring trajectory data of forward solution and related calculation formulas to achieve high-precision mapping and positioning of underground pipelines.

[0142] Implementation method 9: This implementation method further limits the underground pipeline dead reckoning method based on start and end point correction and forward and reverse information multiplexing described in implementation method 1. In this implementation method, the method for obtaining the corrected trajectory information in step 9 is further limited, specifically:

[0143] The corrected trajectory information is obtained by using the summation and averaging formula, which is:

[0144]

[0145] Among them, x, y, z represent the corrected trajectory information, x″1, y″1, z″1 represent the trajectory data of the forward solution, and x″2, y″2, z″2 represent the trajectory data of the reverse solution.

[0146] This embodiment provides a specific method for obtaining the corrected trajectory information and related calculation formulas to achieve high-precision mapping and positioning of underground pipelines.

[0147] Embodiment 10: This embodiment is based on an embodiment of an underground pipeline dead reckoning method based on start and end point correction and forward and reverse information multiplexing as described above, specifically:

[0148] The method of the present invention is simulated using Matlab.

[0149] First, the coordinates of the starting point of the underground pipeline (x start ,ystart ,z start ) and the end point coordinates (x end ,y end ,z end ) is bound to the program, and the pipeline inertial positioning instrument is kept still for 2 minutes. The pipeline inertial positioning instrument MIMU data is collected at a sampling frequency of 10 Hz to complete the initial alignment and obtain the initial attitude matrix The formula for obtaining the initial matrix is:

[0150]

[0151] Among them, f bi (i=x, y, z) represents the measurement output value of the MIMU three-axis accelerometer, and g represents the local gravity acceleration value.

[0152] Then, the obtained initial posture matrix is ​​converted into the initial posture quaternion Right now:

[0153]

[0154]

[0155] Among them, C ij (i=1,2,3;j=1,2,3) represents the attitude matrix The elements in , q0 represent the normalized initial attitude quaternion.

[0156] Furthermore, the pipeline inertial positioning device obtains MIMU gyroscope data in real time during the movement and substitutes it into the quaternion differential equation:

[0157]

[0158] in, represents the projection of the rotation angular rate of the carrier system relative to the navigation system on the x-axis, y-axis and z-axis of the carrier system, q 0i (i=0,1,2,3) represents the normalized initial attitude quaternion in projection form, that is, the element in the normalized initial attitude quaternion q0, The derivative of the attitude quaternion expressed in projected form.

[0159] The fourth-order Runge-Kutta method is used to solve the above quaternion differential equation:

[0160]

[0161]

[0162]

[0163]

[0164] Among them, Ω i (i=1,2,3) represents the antisymmetric matrix formed by the sampling output of three MIMU gyroscopes, T is the sampling time, and q is the updated attitude quaternion.

[0165] Next, the mileage information output by the odometer in the carrier system is converted into speed information in the navigation coordinate system through the updated attitude quaternion:

[0166]

[0167]

[0168] in, is the attitude matrix from the carrier system to the navigation system, dS is the mileage increment information output by the odometer, and T is the odometer output sampling interval.

[0169] Then, the velocity information v in the navigation coordinate system is n The three-dimensional position information (i.e., trajectory position information) in the Cartesian coordinate system is obtained by iteratively summing the sampling interval time T:

[0170]

[0171] Among them, v i (i=E,N,U) represents the eastward, northward and celestial velocity information in the Cartesian coordinate system.

[0172] Next, the initial binding start and end position information (x start ,y start ,z start )、(x end ,y end ,z end ) and the three-dimensional position information (x' end ,y' end ,z' end ) Construct the correction transformation matrix

[0173]

[0174]

[0175]

[0176]

[0177]

[0178]

[0179]

[0180] Among them, x start y start z start is the three-dimensional coordinate of the starting point, x end y end z end is the three-dimensional coordinate of the end point, x′ end y′ end z′ end is the three-dimensional coordinate of the dead reckoning endpoint, K1 and K2 are the horizontal and height scale transformation factors, ψ1-ψ2 and ψ3-ψ4 are the horizontal azimuth error and height azimuth error, respectively. is the correction matrix.

[0181] Then, the three-dimensional position information in the Cartesian coordinate system is corrected by the correction matrix, and the corrected trajectory position information is obtained as follows:

[0182]

[0183] Similarly, when solving in reverse, the corrected trajectory position information can be obtained by following the above steps:

[0184]

[0185] Finally, the trajectory position information after the forward and reverse corrections is summed and averaged to obtain the trajectory position after the forward and reverse trajectories are fused:

[0186]

[0187] Finally, in order to verify the effectiveness of the dead reckoning method based on start-end point correction and forward and reverse information multiplexing proposed in the present invention, a simulation experiment is specially set up, and compared and analyzed with the traditional dead reckoning method.

[0188] The simulation conditions are set as follows:

[0189]

[0190] like Figure 1 As shown, Figure 1 The comparison charts of the real trajectory, dead reckoning, end point correction, start and end point correction and information multiplexing trajectory are shown; Figure 2 The error curves of the start and end point correction and information reuse are shown in the following table. At the same time, different gyro biases were set to conduct multiple simulation experiments, and the maximum experimental error and the experimental error RMS statistics were shown in the following table:

[0191]

[0192] From the above table, it can be seen that the gyro zero bias is within 20° / h. The maximum horizontal positioning error measured by the method proposed in the present invention is within 10 cm under the simulated pipeline length of 100 m, and the maximum height positioning error is within 10 cm. Compared with the traditional method, it has higher positioning accuracy.

Claims

1. A method for dead reckoning of underground pipelines based on start-end point correction and forward and reverse information multiplexing, characterized in that: The method comprises: Step 1: Bind the starting and ending position information of the pipeline into the pipeline inertial positioning instrument; Step 2: Collect MIMU data using the pipeline inertial positioning instrument, and construct an initial attitude matrix according to the MIMU data; Step 3, converting the initial posture matrix into an initial quaternion and normalizing the initial quaternion; Step 4: Obtain MIMU gyroscope data, substitute the MIMU gyroscope data into the quaternion differential equation, and use the fourth-order Runge-Kutta method to solve the quaternion differential equation to obtain an updated attitude quaternion; Step 5: Using the updated attitude quaternion, convert the odometer measurement value in the carrier system into speed information in the navigation coordinate system; Step 6: Obtain trajectory position information by using the velocity information in the navigation coordinate system and the iterative summation of the sampling interval time integral; Step 7: construct a correction transformation matrix according to the starting and ending position information of the pipeline and the starting and ending coordinates in the trajectory position information, complete the forward solution trajectory correction, and obtain the forward solution trajectory data; Step 8: Keep the heading of the pipeline inertial locator unchanged, make the pipeline inertial locator move in reverse from the end position to the starting position, repeat steps 1 to 7 to obtain the trajectory information after reverse solution correction, and obtain the trajectory data of reverse solution; Step 9: sum and average the trajectory data obtained by the forward solution and the trajectory data obtained by the reverse solution at corresponding positions to obtain corrected trajectory information; Step 7 specifically includes: Step 7.1: construct a correction transformation matrix according to the pipeline start and end position information and the start and end coordinates in the trajectory position information, wherein the start and end coordinates include the three-dimensional coordinates of the starting point and the three-dimensional coordinates of the end point. The specific formula is as follows: Among them, x start y start z start is the three-dimensional coordinate of the starting point, x end y end z end is the three-dimensional coordinate of the end point, x′ end y′ end z′ end is the three-dimensional coordinate of the dead reckoning endpoint, K1 and K2 are the horizontal and height scale transformation factors, ψ1-ψ2 and ψ3-ψ4 are the horizontal azimuth error and height azimuth error, respectively. is the correction matrix; Step 7.2: Use the correction matrix to correct the trajectory information and obtain the trajectory data of the forward solution:

2. The underground pipeline dead reckoning method based on start-end point correction and forward and reverse information multiplexing according to claim 1 is characterized in that: In step 2, the method of constructing the initial posture matrix is ​​specifically as follows: The initial matrix is ​​obtained by using the formula to construct the initial posture matrix. The formula for obtaining the initial matrix is: Among them, C ij (i=1,2,3;j=1,2,3) represents the attitude matrix The elements in f bi (i=x, y, z) represents the measurement output value of the MIMU three-axis accelerometer, and g represents the local gravity acceleration value.

3. The underground pipeline dead reckoning method based on start-end point correction and forward and reverse information multiplexing according to claim 1 is characterized in that: In step 3, the initial posture matrix is ​​converted into an initial quaternion, specifically: the initial posture matrix is ​​converted into an initial quaternion using a conversion formula, and the conversion formula is: Among them, C ij (i=1,2,3;j=1,2,3) represents the attitude matrix The elements in is the initial attitude quaternion.

4. The underground pipeline dead reckoning method based on start-end point correction and forward and reverse information multiplexing according to claim 1 is characterized in that: In step 3, the normalization of the initial quaternion is specifically: using a normalization formula to normalize the initial quaternion, the normalization formula is: Among them, q0 represents the normalized initial attitude quaternion.

5. The underground pipeline dead reckoning method based on start-end point correction and forward and reverse information multiplexing according to claim 1 is characterized in that: Step 4 specifically includes: Step 4.1, obtain MIMU gyroscope data, and substitute the MIMU gyroscope data into the quaternion differential equation, the quaternion differential equation is: in, represents the projection of the rotation angular rate of the carrier system relative to the navigation system on the x-axis, y-axis and z-axis of the carrier system, q 0i (i=0,1,2,3) represents the elements in the normalized initial attitude quaternion q0, The derivative of the attitude quaternion expressed in projected form; Step 4.2: Solve the quaternion differential equation using the fourth-order Runge-Kutta method to obtain Step 4.3: Obtain the updated attitude quaternion using the update formula, the update formula is: Among them, Ω i (i=1,2,3) represents the antisymmetric matrix formed by the sampling output of three MIMU gyroscopes, T is the sampling time, and q is the updated attitude quaternion.

6. The underground pipeline dead reckoning method based on start-end point correction and forward and reverse information multiplexing according to claim 1 is characterized in that: Step 5 specifically includes: Step 5.1: Using the updated attitude quaternion, obtain the attitude matrix from the carrier system to the navigation system: Step 5.2: Use the attitude matrix of the carrier system to the navigation system Get the speed information in the navigation coordinate system: Among them, dS is the mileage increment information output by the odometer, and T is the odometer output sampling interval.

7. The underground pipeline dead reckoning method based on start-end point correction and forward and reverse information multiplexing according to claim 1 is characterized in that: Step 6, specifically: Using the speed information v in the navigation coordinate system n , the trajectory position information is obtained by integrating and iterating the sampling interval time T: Among them, v i (i=E,N,U) represents the eastward, northward and celestial velocity information in the Cartesian coordinate system.

8. The underground pipeline dead reckoning method based on start-end point correction and forward and reverse information multiplexing according to claim 1 is characterized in that: In step 9, the method for obtaining the corrected trajectory information is specifically as follows: The corrected trajectory information is obtained by using the summation and averaging formula, which is: Among them, x, y, z represent the corrected trajectory information, x”1, y”1, z”1 represent the trajectory data of forward solution, and x”2, y”2, z”2 represent the trajectory data of reverse solution.

9. A computer device comprising a memory and a processor, wherein a computer program is stored in the memory, wherein: When the processor runs the computer program stored in the memory, the steps of the method according to any one of claims 1 to 8 are performed.

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