Power pipeline trenchless laying device and positioning method

Abstract

This invention relates to the field of power pipeline construction and underground target positioning technology, and particularly to a trenchless power pipeline laying device and positioning method. It includes: deploying a ground reference coil array and establishing a ground coordinate benchmark; installing a positioning probe assembly on a haulage head and connecting it to the power pipeline; mutual calibration by applying calibration excitation and collecting calibration responses to obtain a calibration parameter set; applying positioning excitation and collecting electromagnetic / inertial / mileage / tension data during the positioning phase; constructing an electromagnetic feature vector and obtaining electromagnetic positioning results; obtaining inertial mileage positioning results based on inertia and mileage; optimizing and outputting fused positioning results via a sliding window and outputting deviation prompts / control commands, recording positioning quality indicators; wherein cable laying and retrieval can draw inspiration from shipboard hydrological and geological survey winches, and connection reliability can draw inspiration from deep-sea general-purpose materials and connectors and other auxiliary equipment. This invention suppresses cumulative errors through ground coil excitation and multi-source fusion correction.

Description

Technical Field

[0001] This invention relates to the field of power pipeline construction and underground target positioning technology, and in particular to a trenchless power pipeline laying device and positioning method. Background Technology

[0002] Trenchless laying of power pipelines typically involves directional drilling, borehole enlargement, and pullback pipe laying. To meet the needs of as-built documentation, subsequent operation and maintenance, and avoidance of third-party construction, it is usually necessary to obtain the trajectory information of the pullback head and the power pipeline underground during construction. However, due to the lack of visibility of the underground environment, the long construction distance, and frequent changes in working conditions, the positioning process often relies on sensors that move with the pullback head to collect attitude and displacement data, and then uses algorithms to calculate the position.

[0003] In the prior art, combined positioning schemes for trenchless pipeline positioning have been disclosed. For example, CN114909608B discloses a trenchless pipeline positioning method based on a combination of MIMU, odometer wheel, and photoelectric speed sensor. This scheme reduces positioning errors caused by odometer wheel slippage by using redundant speed measurement and fusion filtering, thereby improving the impact of unstable odometer wheel speed information on positioning accuracy. Such schemes use inertial measurement and odometer / speed information as the main observables, and enhance the stability and reliability of positioning through redundancy and fusion.

[0004] In the actual working conditions of trenchless back-hauling of power pipelines, factors such as changes in back-hauling load and resistance, mud adhesion, and changes in the contact state between the pipeline and equipment during back-hauling may cause fluctuations in mileage / velocity information in certain sections. Simultaneously, the integral drift of inertial measurements may accumulate over time. Furthermore, trenchless laying sites often require several auxiliary devices and components to support long-distance back-hauling operations and signal transmission. These include winch-type equipment for cable laying and retrieval (including structural forms and cable laying control methods that can be referenced from ship hydrological and geological survey winches), and materials and connecting components for long-term service in harsh environments (including corrosion resistance, pressure resistance, sealing, and reliable connection characteristics that can be referenced from deep-sea general-purpose materials and connectors). Given these complex working conditions and auxiliary equipment configurations, the lack of stable reference information for real-time correction of positioning results may lead to accumulated errors and affect the usability of the trajectory results.

[0005] Therefore, the most pressing technical problem that existing technologies need to solve is: how to obtain reference information that can be used for positioning correction during trenchless back-laying, so as to suppress the cumulative positioning error caused by fluctuations in mileage / speed information and inertial drift. Summary of the Invention

[0006] To overcome the aforementioned technical deficiencies, the present invention aims to provide a trenchless power pipeline laying device and positioning method. The present invention applies identifiable excitation using a ground reference coil array during the trenchless backhaul process and collects multi-source data such as electromagnetic, inertial, and mileage data from the backhaul head positioning probe. Based on mutual calibration and feature library matching, electromagnetic positioning results are obtained and fused with inertial mileage positioning results through a sliding window optimization, thereby introducing reference information that can be used for correction to suppress accumulated errors.

[0007] This invention discloses a trenchless laying and positioning method for power pipelines, comprising:

[0008] S1, deploy a ground reference coil array on the ground along the designed route of the power pipeline to be laid, and establish a ground coordinate benchmark;

[0009] S2, Install the positioning probe assembly onto the tractor unit and connect the tractor unit to the end of the power pipeline; wherein, the positioning probe assembly includes at least a triaxial receiving coil group, an inertial measurement assembly, a mileage measurement assembly, and a tension acquisition assembly;

[0010] S3, before the start of back-to-base laying, a mutual calibration process is performed. The mutual calibration process includes at least: applying calibration excitation to the ground reference coil array and acquiring the calibration response to obtain a set of calibration parameters;

[0011] S4, during the back-laying process, the ground reference coil array is subjected to positioning excitation according to the preset coding sequence, and the positioning probe assembly synchronously collects electromagnetic induction measurement data, inertial measurement data, mileage measurement data and tension data;

[0012] S5. Based on the calibration parameter set, the electromagnetic induction measurement data is characterized to obtain electromagnetic feature vectors, and the electromagnetic feature vectors are matched with the electromagnetic feature library to obtain electromagnetic positioning results.

[0013] S6, Obtain inertial odometer positioning results based on inertial measurement data and odometer measurement data;

[0014] S7, based on the electromagnetic positioning results and the inertial odometry positioning results, performs sliding window fusion optimization and outputs the fused positioning results of the tractor unit;

[0015] S8 calculates the deviation based on the fused positioning results and the designed route, and outputs deviation prompts or control commands;

[0016] S9 records the fusion positioning results and the corresponding positioning quality indicators.

[0017] Preferably, the mutual calibration process includes: selecting coil units in the ground reference coil array as calibration transmitting coils in a preset order during the calibration period, and applying calibration excitation to the calibration transmitting coils; the triaxial receiving coil group of the positioning probe assembly collects the corresponding calibration response to generate calibration parameters in the calibration parameter set for each coil unit.

[0018] Preferably, the calibration parameters include amplitude calibration coefficients. Amplitude calibration coefficient Determined by the following formula:

[0019]

[0020] in, This refers to the calibration response amplitude acquired by the positioning probe assembly during the calibration period. This is the preset reference amplitude.

[0021] Preferably, the feature construction includes: the triaxial electromagnetic response amplitude acquired within a single sampling period. , , Normalization is performed to obtain the normalized electromagnetic eigenvectors. ,satisfy:

[0022]

[0023]

[0024] in, This is a normalized scaling factor.

[0025] Preferably, matching includes minimizing the matching cost function. To obtain electromagnetic positioning results, including the estimated location obtained from matching. ,satisfy:

[0026]

[0027] in, For the location variable to be estimated, For the first Normalized electromagnetic eigenvectors for each sampling period, For the electromagnetic feature library at location The predicted feature vector at that location, This represents the number of sampling periods within the sliding window.

[0028] Furthermore, estimate the location. To make the matching cost function The positional variable that reaches its minimum value.

[0029] Preferably, the electromagnetic feature library is a table established by creating discrete location points along the designed route, and the predicted feature vectors... Based on amplitude calibration coefficient It is generated after updating the electromagnetic feature library.

[0030] Preferably, the sliding window fusion optimization includes: based on the matching residual scalar Electromagnetic residual weights are assigned to the electromagnetic positioning results. The electromagnetic positioning results and inertial odometry positioning results are fused within a sliding window, and the electromagnetic residual weights are adjusted accordingly. satisfy:

[0031]

[0032] Among them, the matching residual scalar satisfy:

[0033]

[0034] in, To match the cost function at the estimated location according to claim 5 The function value at that point, This represents the number of sampling periods within the sliding window.

[0035] Preferably, when matching residual scalars Exceeding the threshold When changing the way the ground reference coil array applies positioning excitation according to a preset coding timing sequence, the changes include at least one or more of the following: switching the excitation frequency set, adjusting the excitation time slot length, or switching the coil unit subset participating in the excitation.

[0036] Preferably, the power pipeline is formed by connecting multiple pipe sections, and electronic identification elements are set at at least some of the pipe section connections; when the positioning probe assembly identifies the electronic identification element, the fusion positioning result at the corresponding time is written as a verification point into the sliding window fusion optimization process.

[0037] Preferably, the electronic identifier is a radio frequency identifier, and the positioning probe assembly includes a radio frequency reading module, which performs allocation correction on the mileage increment sequence corresponding to the mileage measurement data in the segment based on the cumulative mileage error between two adjacent verification points.

[0038] Preferably, the positioning quality index includes position uncertainty. And positional uncertainty satisfy:

[0039]

[0040] in, , , The fusion localization results are respectively in , , The standard deviation of the estimated direction; when Exceeding the threshold Output verification or shutdown commands at any time.

[0041] Preferably, the mileage measurement component is a dual-mileage wheel component, which outputs the first mileage increment in a single sampling period. With the second mileage increment .

[0042] Preferably, the mileage input for the inertial odometry positioning result is the mileage increment after slippage correction. And slippage correction coefficient Mileage increment satisfy:

[0043]

[0044]

[0045] in, This is a preset reference increment threshold.

[0046] Preferably, the tension acquisition component acquires the pullback tension. And based on the pullback tension Mileage increment Compensation is performed to obtain the compensated mileage increment. ,satisfy:

[0047]

[0048] in, This is the tension compensation coefficient. The reference tension is used; and the inertial odometer positioning results are based on odometer increments. Perform a recursive process.

[0049] In view of this, a second objective of the present invention is to provide a trenchless power pipeline laying device, comprising:

[0050] The system includes a directional drilling unit, a traction and pullback unit, a pipe supply unit, a pullback head, and a control terminal. The traction and pullback unit includes a pullback winch and a traction cable. The pullback winch is used to drive the traction cable to pull back the power pipeline.

[0051] The tractor unit is equipped with a positioning probe assembly, which includes at least a triaxial receiving coil group, an inertial measurement assembly, a mileage measurement assembly, and a tension acquisition assembly.

[0052] The device also includes a ground reference coil array and a coil drive assembly, the coil drive assembly being used to apply calibration excitation and positioning excitation to the ground reference coil array according to a preset coding timing sequence;

[0053] The control terminal is communicatively connected to both the positioning probe assembly and the coil drive assembly, and is configured to perform the positioning method described above.

[0054] Furthermore, the positioning probe assembly and the control terminal are electrically connected via a pressure-resistant and waterproof connector.

[0055] Compared with existing technologies, the above technical solution has the following advantages:

[0056] 1. Strong ability to suppress cumulative positioning error and high trajectory availability: Identifiable reference information is provided by ground reference coil array, and the estimated position is obtained by matching based on electromagnetic feature library. The position is fused and optimized by sliding window with the inertial mileage recursion result, so that the positioning process is continuously corrected and constrained, reducing the cumulative error caused by mileage / velocity fluctuation and inertial drift under long-distance towing conditions.

[0057] 2. Better stability and controlled error peak under complex working conditions: Electromagnetic residual weights are constructed based on matching residuals, and the positioning excitation mode is adaptively adjusted (switching frequency set, adjusting time slot length or switching coil unit subset) when the matching residual exceeds the threshold, which improves the identifiability of interference section and coupling change section and reduces the risk of sudden changes in positioning results.

[0058] 3. More robust to slippage and load fluctuations: The slippage correction coefficient is constructed by using the difference between the two mileage increments of the dual mileage wheel output, and the pullback tension is introduced to compensate for the mileage increment, making the mileage input closer to the actual working conditions, which helps to reduce the impact of slippage and load changes on displacement recursion.

[0059] 4. Segmented verification and error closure: Radio frequency identification devices are set at the pipe section connection as verification points. The verification points are written into the fusion process, and the mileage increment sequence between adjacent verification points is allocated and corrected to achieve segmented error constraint and closure, further reducing drift accumulation during long-distance towing.

[0060] 5. Strong feasibility and engineering adaptability: Calibration parameters are obtained through mutual calibration and the differences in coil units are uniformized. Combined with pressure-resistant and waterproof connectors and cable-following links (which can draw on the reliable connection structure of auxiliary equipment such as universal deep-sea materials and connectors) and cable laying and retrieval control (which can draw on the cable laying control method of ship hydrological and geological survey winches), it is easy to implement stably in construction environments such as mud and moisture.

[0061] 6. Possesses quality quantification and safety control capabilities: Outputs positioning quality indicators such as position uncertainty, and issues verification or shutdown instructions when thresholds are exceeded, which is beneficial for risk warning and quality control during the construction process. Attached Figure Description

[0062] Figure 1 This is a schematic diagram of the trenchless pullback positioning system.

[0063] Figure 2 A schematic diagram of time-slot coding for calibration and positioning excitations;

[0064] Figure 3 This is a schematic diagram illustrating the steps of the trenchless power pipeline laying device and positioning method of the present invention;

[0065] Figure 4 This is a schematic diagram comparing the change of horizontal error with distance.

[0066] Figure 5 This is a schematic diagram of the relationship between electromagnetic residual weights and matching residuals.

[0067] Figure 6 A schematic diagram illustrating the correction of segmented error allocation for radio frequency verification points;

[0068] Figure 7 This is a schematic diagram showing the relationship between the difference in mileage between the two wheels and the slippage correction factor;

[0069] Figure 8 This is a schematic diagram showing the relationship between pullback tension and mileage compensation factor. Detailed Implementation

[0070] The advantages of the present invention will be further illustrated below with reference to the accompanying drawings and specific embodiments.

[0071] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this disclosure. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this disclosure as detailed in the appended claims.

[0072] The terminology used in this disclosure is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. The singular forms “a,” “the,” and “the” as used in this disclosure and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any and all possible combinations of one or more of the associated listed items.

[0073] It should be understood that although the terms first, second, third, etc., may be used in this disclosure to describe various information, such information should not be limited to these terms. These terms are used only to distinguish information of the same type from one another. For example, without departing from the scope of this disclosure, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the word "if" as used herein may be interpreted as "when," "when," or "in response to determination."

[0074] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0075] In the description of this invention, unless otherwise specified and limited, it should be noted that the terms "installation", "connection" and "linking" should be interpreted broadly. For example, they can refer to mechanical or electrical connections, or internal connections between two components. They can be direct connections or indirect connections through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0076] In the following description, suffixes such as "module," "part," or "unit" used to denote elements are used only for the convenience of the description of the invention and have no specific meaning in themselves. Therefore, "module" and "part" can be used interchangeably.

[0077] See Figure 3As shown, this embodiment provides a trenchless positioning method for laying power pipelines, including: S1, deploying a ground reference coil array along the designed route of the power pipeline to be laid and establishing a ground coordinate reference; S2, installing a positioning probe assembly on a pullback head and connecting the pullback head to the end of the power pipeline; wherein, the positioning probe assembly includes at least a triaxial receiving coil group, an inertial measurement assembly, a mileage measurement assembly, and a tension acquisition assembly; S3, performing a mutual calibration process before the start of pullback laying, the mutual calibration process including at least: applying calibration excitation to the ground reference coil array and acquiring calibration responses to obtain a calibration parameter set; S4, during the pullback laying process, applying positioning excitation to the ground reference coil array according to a preset coding sequence. The positioning probe assembly simultaneously collects electromagnetic induction measurement data, inertial measurement data, mileage measurement data, and tension data; S5, based on the calibration parameter set, the electromagnetic induction measurement data is used to construct features to obtain electromagnetic feature vectors, and these electromagnetic feature vectors are matched with the electromagnetic feature library to obtain electromagnetic positioning results; S6, inertial mileage positioning results are obtained based on inertial measurement data and mileage measurement data; S7, sliding window fusion optimization is performed based on the electromagnetic positioning results and inertial mileage positioning results, and the fusion positioning results of the tractor are output; S8, the deviation is calculated based on the fusion positioning results and the designed route, and deviation prompts or control commands are output; S9, the fusion positioning results and the corresponding positioning quality indicators are recorded.

[0078] For ease of understanding, the technical names and identifiers are explained in advance in this embodiment:

[0079] This embodiment provides a positioning method for trenchless laying of power pipelines, applicable to construction scenarios involving directional drilling, borehole enlargement, and pullback laying of power pipelines. It aims to acquire the underground trajectory of the pullback head and power pipeline under conditions where the underground is not visible, operating conditions fluctuate significantly, mileage / speed information may fluctuate, and inertial drift may accumulate over time. Externally identifiable reference information is introduced into the positioning process to reduce accumulated positioning errors. For ease of description and to maintain consistency in technical terminology, this embodiment provides unique symbols for the main structures and signals upon their first appearance: Ground Reference Coil Array (Ground Reference Coil Array) ), coil drive assembly (coil drive assembly) ), control terminal (control terminal) ), Positioning probe assembly (positioning probe assembly) ), triaxial receiving coil group (triaxial receiving coil group) Inertial Measurement Unit (IMU) ), Mileage measurement component (mileage measurement component) Dual-mileage wheel assembly (dual-mileage wheel assembly) Tension acquisition component (tension acquisition component) ), RF reading module (RF reading module) Pressure-resistant and waterproof connectors ), return tractor (return tractor) ), power pipelines (power pipelines) ), traction cable (traction cable) Ship hydrographic and geological survey winches (ship hydrographic and geological survey winches) ), calibration stimulus (calibration stimulus) Positioning incentives (positioning incentives) ), calibration parameter set (calibration parameter set) Electromagnetic feature library (electromagnetic feature library) ).

[0080] It should be noted that the on-site configuration will be described in detail in this embodiment:

[0081] like Figure 1 As shown, a ground reference coil array is laid on the ground along the designed route of the power pipeline to be laid. The ground reference coil array consists of multiple coil units, which can be closed coil structures formed by winding multiple turns of wire, preferably circular or rectangular coils. The coil drive component is electrically connected to the ground reference coil array and is used to apply calibration excitation or positioning excitation to selected coil units at different working stages. The control terminal is used to schedule the excitation timing, receive and store measurement data, perform mutual calibration operations, perform feature construction and matching operations, perform sliding window fusion optimization, and output fusion positioning results and positioning quality indicators. The positioning probe component is installed at the return tow head, which is connected to the end of the power pipeline and pulled back by a traction cable. The positioning probe component and the control terminal are electrically or communicatively connected through the cable-fed link. The cable-fed link is deployed and retrieved by the ship's hydrological and geological survey winch or by adopting its cable-fed control method. The pressure-resistant and waterproof connector is located at the connection point between the positioning probe assembly and the cable link. The pressure-resistant and waterproof connector can use common deep-sea materials and corrosion-resistant materials, pressure-resistant sealing structures and reliable locking mechanisms commonly used in auxiliary equipment such as connectors, to reduce the impact of mud, water vapor and pressure fluctuations on the reliability of electrical connections.

[0082] The positioning probe assembly includes at least a triaxial receiving coil group, an inertial measurement unit, an odometer measurement unit, and a tension acquisition unit. The triaxial receiving coil group preferably consists of three orthogonally arranged receiving coils to acquire the triaxial electromagnetic response amplitude and reduce the risk of response degradation caused by attitude changes. The inertial measurement unit outputs inertial information such as angular velocity and acceleration, and can further calculate the attitude. The odometer measurement unit outputs the displacement increment during the towing process; in this embodiment, the odometer measurement unit is implemented using a dual-odometer wheel assembly, which outputs two odometer increments for slippage detection and correction. The tension acquisition unit outputs the towing tension data and can be deployed between the towing head and the traction cable or inside the towing head along the force transmission path. The positioning probe assembly also includes a radio frequency (RF) reading module for reading RF markers at pipe joint connections, thereby providing segmented verification point information to help eliminate accumulated errors.

[0083] It should be noted that the ground coordinate reference conventions will be described in detail in this embodiment:

[0084] In this embodiment, a rectangular coordinate system is used as the ground coordinate reference. The direction of travel along the designed route is defined as the X-axis, the horizontal direction as the Y-axis, and the vertical direction as the Z-axis. The Z-axis can be uniformly set according to the convention of downward or upward positive, and all subsequent calculations are performed under this convention. To facilitate construction management and deviation evaluation, it is preferable to establish a "local construction coordinate system", that is, taking the surface projection point of the starting point of the designed route as the origin and the direction of the designed route as the X-axis direction, so that in the output coordinates, the X-direction corresponds to the mileage advancement, the Y-direction corresponds to the lateral offset, and the Z-direction corresponds to the burial depth or elevation change.

[0085] like Figure 3 As shown, the positioning method in this embodiment generally includes: deploying a ground reference coil array along the designed route and establishing a ground coordinate benchmark; installing a positioning probe assembly on the backhaul head and connecting it to the power pipeline; performing a mutual calibration process and obtaining a calibration parameter set before the backhaul begins; applying positioning excitation according to the coded timing sequence and simultaneously collecting electromagnetic / inertial / mileage / tension data during the backhaul; constructing features based on the calibration parameter set and matching them with the electromagnetic feature library to obtain an estimated position; performing slippage correction and tension compensation on the mileage and combining it with inertial recursion to obtain the inertial mileage positioning result; calculating the electromagnetic residual weight based on the matching residual and fusing and optimizing the output fused positioning result within a sliding window; triggering an adaptive change in the positioning excitation mode when the residual exceeds a threshold; using radio frequency identification devices as verification points at the pipe section connection and performing segmented error allocation correction; outputting positioning quality indicators such as position uncertainty and outputting a verification or shutdown command when the threshold is exceeded.

[0086] It should be noted that the implementation method of step S1 will be described in detail in this embodiment: the deployment of the ground reference coil array and the establishment of the ground coordinate reference are as follows:

[0087] This embodiment breaks down the deployment of the ground reference coil array along the designed route and the establishment of the ground coordinate benchmark into five sub-processes: "design route analysis - deployment scheme formulation - on-site layout and coil installation - coil electrical connection and marking - ground coordinate benchmark establishment and verification".

[0088] It should be noted that this embodiment will provide a detailed description of the design route parsing and deployment scheme:

[0089] During the construction preparation phase, the design route information of the power pipeline is obtained. The design route generally consists of several design control points, which may include mileage, plane coordinates, and elevation information. The coordinate sequence of the centerline of the design route can be pre-imported into the control terminal and used for subsequent layout point calculation and management. The preferred layout scheme follows these principles: the center point of the coil unit should be as close as possible to the ground projection of the centerline of the design route; the spacing between coil units is determined based on the pullback speed, sampling period, and desired spatial resolution, typically ranging from 10m to 30m, and can be densified in sections with significant interference; the coil plane should be as consistent as possible (preferably horizontal or consistent with the local ground surface normal), and attitude information should be recorded; strong electromagnetic interference sources and large metal components should be avoided near the coils as much as possible, and if necessary, avoidance should be achieved through excitation frequency set and subset excitation strategies.

[0090] Example: If the designed route is approximately 300m long and the coil units are to be deployed at 20m intervals, then approximately 16 coil units can be set up and numbered "Unit 1 to Unit 16". If there are road intersections and metal guardrails or other interference in the section between 120m and 160m, the spacing can be reduced to 10m in this section and the coil units can be moved to a safe location on the roadside. At the same time, this section can be marked as an interference section in the control terminal so that the adaptive excitation strategy can be triggered later.

[0091] It should be noted that the on-site layout and coil installation will be described in detail in this embodiment:

[0092] On-site layout can be performed using a total station or high-precision satellite positioning equipment, with the preferred method being "control point—centerline layout—coil center point layout". First, select at least two stable control points and determine their coordinates as reference base points; then, calculate the target positions of the center points of each coil unit according to the design route centerline and lay them out on-site, marking them with wooden stakes or marker nails, and recording the mileage, number, and surrounding features. Coil installation follows these steps: clean and level the installation area → place the coil unit → fix it using ground stakes / sandbags / brackets → measure and record the coil attitude (pitch / roll) → connect the coil leads to the waterproof junction box → connect to the coil drive assembly → insulation and continuity testing.

[0093] For ease of understanding, the following parameter examples are provided in this embodiment:

[0094] The coil diameter is 1.0m to 1.6m, and the number of turns is 20 to 80. The output current amplitude of the coil drive component is 1A to 5A, and the output voltage is 24V to 120V (example range), and it is equipped with overcurrent / temperature rise protection. Warning signs can be set around the coil unit, and barriers can be added or the coil can be relocated at high-risk locations such as intersections, with the offset recorded in the inventory table.

[0095] It should be noted that this embodiment will provide a detailed description of the coil electrical connection, numbering management, and "encoding timing" configuration:

[0096] After the coil unit is connected to the coil drive assembly, the control terminal establishes a mapping relationship such as "unit number - drive channel - ground coordinates - attitude - cable length" and configures the positioning excitation coding timing sequence. Positioning excitation preferably uses a time-slot method to sequentially excite different coil units or coil subsets, and different frequency sets can be configured for different time slots. (See illustration below.) Figure 2 As shown, the calibration period and the positioning period can be set separately. The calibration period is used for mutual calibration, and the positioning period is used for dragging back for positioning.

[0097] For ease of understanding, the following parameter examples are provided in this embodiment:

[0098] Example calculation: The positioning cycle is 0.20s, and each time slot is 0.04s, so one cycle contains 5 time slots; when the number of coil units is 16, group polling can be used, dividing units 1 to 16 into 4 groups, with 4 units in each group, to complete full coverage polling within 4 consecutive cycles, and to complete one full coverage sampling within 0.8s, and then incorporating the data from multiple cycles into the sliding window for matching.

[0099] It should be noted that the establishment of the ground coordinate reference will be described in detail in this embodiment:

[0100] The preferred ground coordinate reference is a two-tiered approach: global coordinates and local construction coordinates. First, the global coordinates of the control points are obtained using a total station or high-precision satellite positioning. Then, the surface projection point of the design route's starting point is used as the origin of the local construction coordinate system, and the design route direction is used as the X-axis direction of the local construction coordinate system. Let the coordinates of the origin point in the global coordinate system be... The center point of the coil is Then the relative vector is Let the angle between the X-axis of the local construction coordinate system and the global X-direction be . Then the local coordinates for:

[0101]

[0102]

[0103] in The coordinates are determined by the azimuth angles of the origin point and the direction reference point. Through transformation, the coordinates of the coil unit center point and the design route are uniformly expressed in the local construction coordinate system, which facilitates subsequent deviation evaluation and trajectory output.

[0104] For ease of understanding, the following example is given in this embodiment:

[0105] Origin point global coordinates (Unit: m, example) Directional reference point but The center point of a certain coil Local coordinates .

[0106] It should be noted that the verification of coordinates and deployment results will be described in detail in this embodiment, as follows:

[0107] After coordinate establishment is completed, the control terminal checks the consistency of coil unit coordinates (mileage monotonicity, spacing range, attitude threshold). After coil installation, the coil center point coordinates can be remeasured and compared with the staked-out coordinates. If the deviation exceeds the threshold, adjustments are made and the list is updated. Low-power calibration excitation can be applied and the response collected to quickly determine if the wiring is correct and if there is an open circuit / short circuit. Example: Staked-out coordinates Retest Then the plane deviation is:

[0108]

[0109] If the threshold is 0.20m, a prompt will be made to review or to add a correction amount when updating the database table.

[0110] It should be noted that the implementation method of step S2 will be described in detail in this embodiment: installation of the positioning probe assembly, cable connection and protection, as follows:

[0111] The positioning probe assembly is mounted near the proximal end or internal cavity of the haulage head, preferably near the geometric center and as far away as possible from strong magnetic components to reduce distortion. The mounting base may include anti-vibration pads, positioning pins, and locking structures to ensure that relative slippage does not occur under haulage vibration and impact. The coordinate axis direction of the triaxial receiving coil assembly is preferably aligned with the forward direction of the haulage head, and the alignment angle is recorded for attitude compensation.

[0112] The positioning probe assembly is connected to the control terminal via a pressure-resistant and waterproof connector and the accompanying cable link. The pressure-resistant and waterproof connector preferably features a double-seal structure and an anti-loosening structure, and employs corrosion-resistant and pressure-resistant sealing materials and structures, drawing on the reliable connection characteristics of commonly used deep-sea materials and connectors, as well as other auxiliary equipment. The deployment and retrieval of the traction cable are accomplished by the ship's hydrological and geological survey winch or by adopting its deployment control methods to achieve stable tension control and accompanying cable length management, reducing damage to the link and connectors from transient tension.

[0113] It should be noted that the implementation method of step S3 will be described in detail in this embodiment: the mutual calibration process and the meaning of the parameters are as follows:

[0114] The mutual calibration process is used to establish consistency parameters between the coil unit excitation and the receiving link. The mutual calibration process includes at least: applying calibration excitation to the ground reference coil array and acquiring the calibration response to obtain a calibration parameter set. Specifically, during the calibration period, coil units are selected as calibration transmitting coils in a preset order. The coil driving component applies the calibration excitation, the triaxial receiving coil group acquires the calibration response and uploads it to the control terminal, and the control terminal calculates the calibration parameters and writes them into the calibration parameter set. The calibration excitation can be a single-frequency sinusoidal signal, and a time-slot method is used to excite each unit sequentially to avoid crosstalk. Figure 2 (Illustration)

[0115] The calibration parameters must include at least the amplitude calibration factor, which is denoted as . The formula for its calculation is:

[0116]

[0117] in, The measured calibration response amplitude during the calibration period. This is the preset reference amplitude.

[0118] For ease of understanding, the following example is given in this embodiment:

[0119] Example 1: , ,but:

[0120]

[0121] Example 2: , ,but:

[0122]

[0123] The amplitude calibration coefficient can be used to standardize the differences in coil unit gain, drive link gain, and receiver gain, providing a basis for subsequent feature library matching.

[0124] It should be noted that the implementation method of step S4 will be described in detail in this embodiment: positioning excitation encoding, time alignment and multi-source data acquisition, as follows:

[0125] Upon entering the pullback positioning phase, the coil drive component applies positioning excitation to the ground reference coil array according to the preset coding sequence. The positioning excitation can adopt the method of "time slot coding + frequency set", that is, each positioning cycle contains several time slots, each time slot excites a coil unit or a subset of coils, and one or more frequency points are used in the time slot to enhance the identifiability and anti-interference.

[0126] To ensure effective fusion, the control terminal and the positioning probe assembly establish a unified time reference. The control terminal can periodically send time synchronization frames, and the positioning probe assembly corrects local clock drift and adds timestamps to the data. The excitation time slots of the coil drive assembly are also scheduled by the control terminal and timestamps are recorded, aligning the excitation with electromagnetic sampling. The sampling periods for inertial measurement, dual-mileage wheel, and tension acquisition are preferably consistent with the fusion period (e.g., 0.1s or 0.05s). Electromagnetic sampling can be completed within each time slot and synthesized into an electromagnetic feature vector output at the end of the period.

[0127] For ease of understanding, the following example is given in this embodiment:

[0128] With a pullback speed of 0.25 m / s and a sampling period of 0.1 s, the displacement per period is approximately 0.025 m. With a sliding window length of 10, the window coverage is approximately 1.0 s, corresponding to a displacement of approximately 0.25 m, thus achieving a balance between real-time performance and robustness.

[0129] It should be noted that the implementation method of step S5 will be described in detail in this embodiment: feature construction, feature library establishment, and matching cost function, as follows:

[0130] Construction of normalized electromagnetic eigenvectors:

[0131] The triaxial receiver coil group outputs the triaxial electromagnetic response amplitude. , , First, calculate the normalized scaling factor:

[0132]

[0133] Then calculate the normalized electromagnetic eigenvectors:

[0134]

[0135] Normalization makes the features focus more on the relative relationships of the three axes, reducing the impact of amplitude variations.

[0136] Example: , , ,but:

[0137]

[0138]

[0139] Methods for establishing an electromagnetic feature library:

[0140] An electromagnetic feature library is established along the designed route, with discrete location point tables, and the distance between the discrete points can be 1m to 5m. The electromagnetic feature library can be formed through: pre-construction sampling (collecting responses and recording feature vectors at known coordinate points), simulation model-based library construction (calculating and predicting features based on coil geometry and soil electrical parameters), hybrid library construction, and online small-scale updates (using the simulation library as initial values ​​and combining mutual calibration for consistent updates). To ensure consistency, the electromagnetic feature library can be updated to be consistent with the table based on amplitude calibration coefficients, so that the predicted features in the library table and the features measured in the field are on the same calibration scale.

[0141] Matching cost function and estimated location:

[0142] Matching cost function:

[0143]

[0144] in For the location variable to be estimated, For the first Feature vectors for each sampling period For the electromagnetic feature library at location The predicted feature vector at that location, This is the length of the sliding window. Estimated position. In order to make The positional variable that reaches its minimum value.

[0145] For ease of understanding, the following example is given in this embodiment:

[0146] In candidate position The above calculation yields , , ,but If we take and Then the matching residual scalar:

[0147]

[0148] It should be noted that the implementation method of step S6 will be described in detail in this embodiment: the mileage / slippage / tension related process is as follows:

[0149] Dual-mileage wheel and slippage correction:

[0150] Dual-mileage wheel assembly outputs two mileage increments. , Construction slippage correction factor:

[0151]

[0152] And the corrected mileage increment is obtained:

[0153]

[0154] in This serves as a reference incremental threshold.

[0155] For ease of understanding, the following example is given in this embodiment:

[0156] , , ,but:

[0157]

[0158] Figure 7 It indicated and The relationship is as follows: the greater the difference, the smaller the correction factor, and the lower the reliability of the mileage.

[0159] Tension compensation:

[0160] Tension acquisition component acquires pullback tension Compensated mileage increment

[0161]

[0162] in This is the tension compensation coefficient. This is the reference tension.

[0163] For ease of understanding, the following example is given in this embodiment:

[0164] , , , ,but:

[0165]

[0166] Figure 8 The relationship between tension and compensation factor is illustrated: as tension increases, the compensation factor decreases, making the recursion more conservative.

[0167] Inertial odometry recursion:

[0168] The inertial measurement unit outputs attitude change and acceleration information. The control terminal can then recursively update the data by combining it with the compensated mileage increments to obtain the inertial mileage positioning result in the local construction coordinate system, which is then used as one of the fusion inputs. This embodiment emphasizes slippage correction and tension compensation for the mileage input, as well as subsequent fusion constraints and verification mechanisms, thereby improving the anti-cumulative error capability during long-distance towing.

[0169] It should be noted that the implementation method of step S7 will be described in detail in this embodiment: residuals, weights, and curves, as follows:

[0170] The matching residual scalar is defined as:

[0171]

[0172] Electromagnetic residual weights:

[0173]

[0174] Figure 5 Indication Follow An increase followed by a decrease indicates that the dependence on the electromagnetic matching result is automatically reduced when the matching degenerates.

[0175] For ease of understanding, the following example will be given in this embodiment:

[0176] like ,but:

[0177]

[0178] like ,but:

[0179]

[0180] The fusion optimization can output the fusion positioning results by using a weighted error minimization method within a window, and simultaneously output them for trajectory recording and deviation evaluation.

[0181] It should be noted that the implementation method of step S8 will be described in detail in this embodiment: triggering and hysteresis, as follows:

[0182] when The trigger changes the "method of applying positioning excitation according to the preset coding sequence," including switching the excitation frequency set, adjusting the time slot length, and switching the coil unit subset. To avoid frequent switching, a continuity criterion and a hysteresis criterion can be used: continuity... Sub-threshold triggering, continuous Second lower Restore default settings.

[0183] For ease of understanding, the following example is given in this embodiment:

[0184] Pick , , , , the residual sequence If the threshold is exceeded three times consecutively, a switching mechanism is triggered; if the threshold is subsequently lowered five times consecutively, the default setting is restored. Switching actions may include increasing the proportion of high-frequency components in the frequency set, extending the time slot length, or using a subset of neighboring three-unit excitation.

[0185] It should be noted that the implementation method of step S9 will be described in detail in this embodiment:

[0186] Electronic identifiers, preferably radio frequency (RF) identifiers, are installed at at least some of the pipe section connections of the power pipeline. After the RF reading module reads the RF identifier, a verification point event is triggered. The control terminal writes the fusion positioning result at that moment into the fusion process as a verification point. Based on the reference segment length between two adjacent verification points, the "mileage increment sequence corresponding to the mileage measurement data" within that segment is allocated and corrected.

[0187] Let the reference segment lengths of two adjacent RFID tags be... The mileage increment sequence after compensation within the segment is as follows ,but:

[0188]

[0189]

[0190]

[0191] Figure 6 The diagram illustrates the trend of cumulative mileage curve changes before and after segment correction, with the corrected segment end more closely matching the reference segment length.

[0192] It should be noted that, for ease of understanding, the following example will be given in this embodiment:

[0193] , ,but:

[0194]

[0195] Each of the sections Multiplying by approximately 1.038 and then recursively applying this method can correct the intra-segment error distribution and suppress cumulative drift.

[0196] It should be noted that the positioning quality indicators and threshold control will be described in detail in this embodiment:

[0197] Position uncertainty is defined as ,in , , The estimated standard deviations of the fused positioning results in the X, Y, and Z directions can be obtained from sliding window residual statistics or error propagation. (The threshold is exceeded.) Output verification or shutdown commands in real time.

[0198] For ease of understanding, the following example will be given in this embodiment:

[0199] , , ,but:

[0200]

[0201] If interference section statistics , , ,but:

[0202]

[0203] This can trigger a review strategy.

[0204] It should be noted that the comparative experiments and results will be described in detail in this embodiment:

[0205] To verify the scheme in this embodiment, a field comparison was conducted on a test route approximately 300m long. The comparison scheme employed a conventional process of "inertial measurement + odometer / velocity redundancy + fusion filtering," while this embodiment used a process of "ground reference coil array positioning excitation + mutual calibration + electromagnetic feature library matching + inertial odometer recursion + sliding window fusion optimization + residual-triggered adaptive excitation + RF verification point segmented correction." The true positioning value was obtained through excavation measurements at several sampling points and as-built verification measurements. Figure 4 A schematic curve illustrating the variation of horizontal error with distance is provided.

[0206] Example Table 1 of Field Comparison Test Results

[0207] Combination Figure 4 As can be seen, the error of the comparative scheme has a more obvious trend of accumulation with distance, while this embodiment, by introducing an externally identifiable reference, residual adaptive and segmented correction, exhibits better resistance to cumulative error and trajectory usability under experimental conditions.

[0208] Table 1 presents the statistical results of positioning errors for the proposed scheme and the comparative scheme under the same test route and similar construction conditions. This serves to visually reflect the positioning accuracy levels of the two schemes under different working conditions. In Table 1, "Condition A" represents the section with relatively stable pullback load, and "Condition B" represents the section with fluctuating load and prone to slippage. "Horizontal error" characterizes the deviation of the fused positioning result in the plane direction (XY plane), and "depth error" characterizes the deviation of the fused positioning result in the Z direction (depth direction). The true reference values ​​for these errors are obtained from excavation measurements and as-built verification measurements.

[0209] In Table 1, "Mean Horizontal Error" reflects the average level of the overall error; "P95 Horizontal Error" represents the 95th percentile (i.e., 95% of the errors in the entire statistical sample do not exceed this value), used to characterize the upper bound of the error level at most times; "Maximum Horizontal Error" reflects the peak error under the most unfavorable conditions; and "Mean Depth Error" reflects the average level of the Z-axis deviation. By combining the mean, P95, and maximum values, we can simultaneously observe the three dimensions of "normal accuracy," "stability," and "extreme fluctuations."

[0210] As shown in Table 1, under both operating conditions A and B, the proposed solution generally outperforms the comparative solution in terms of "mean horizontal error, horizontal error P95, maximum horizontal error, and mean depth error," with a particularly significant improvement under operating condition B (load fluctuation / slippage). This indicates that when sections with fluctuating mileage / speed information and more easily accumulated inertial drift occur, the proposed solution, by introducing identifiable reference information provided by a ground reference coil array and combining feature library matching and sliding window fusion optimization, while simultaneously performing slippage correction and tension compensation on the mileage increment, can statistically reduce errors and suppress error peaks, thereby improving the usability of the positioning trajectory results.

[0211] It should be noted that, in this embodiment, the selection of coil unit structure and construction protection details will be further explained:

[0212] The coil unit of the ground reference coil array preferably includes a coil frame, windings, insulation layer, outer sheath, and waterproof junction box. The coil frame can be made of insulating material, the windings can be impregnated and cured, the outer sheath is wear-resistant, water-resistant, and oil-resistant, and the junction box contains waterproof terminal blocks, stress-relieving clips, and sealing rings, and is externally marked with a number plate and direction indicator. The coil drive assembly can record the output current and voltage for each excitation and alert for abnormalities to detect open circuits / short circuits / poor contacts. Field protection can be implemented by setting up barriers or relocating the coil and recording the offset.

[0213] Example Table 2 of Coil Unit Layout and Verification Record

[0214] Table 2 is an example table of the deployment and verification record of the ground reference coil array. It is used to illustrate that in this embodiment, the deployment information, connection relationship and verification results of the coil units are recorded and managed in a structured manner at the construction site, so as to ensure the feasibility and traceability of subsequent mutual calibration, positioning excitation and feature library matching.

[0215] In Table 2, "Coil Unit Number" is used to establish a unique correspondence between coil units and drive channels in the control terminal; "Mileage" reflects the position of the coil unit in the designed route direction; "Local Coordinates x and y" are the coordinates of the coil center point under the ground coordinate reference, used for electromagnetic feature library indexing, trajectory output, and deviation evaluation; "Attitude (Pitch / Roll)" is used to record the tilt of the coil unit plane relative to the horizontal plane, facilitating the inclusion of attitude influence when creating or updating the library table; "Drive Channel Number" is used to ensure that the coil drive component can be correctly selected according to the preset coding sequence; "Cable Length" is used for on-site cable management and anomaly troubleshooting; "Insulation Test" reflects the insulation status of the coil and cable, used to reduce the risk of leakage and measurement anomalies; "Remarks" are used to record on-site feature points and layout instructions, facilitating verification and maintenance.

[0216] The recording and verification mechanism in Table 2 enables engineering traceability of the "deployment-connection-parameter-computation" link, avoiding mutual calibration failures or long-term large matching residuals caused by deployment errors, wiring errors, or insulation abnormalities, thereby supporting the stable operation of the scheme in actual engineering.

[0217] Example Table 3 of Positioning Excitation Encoding Timing Configuration

[0218] Table 3 is an example of the timing configuration for positioning excitation encoding, illustrating how the coil drive component is parameterized during the positioning phase using a structure of "positioning cycle—time slot—excitation method—frequency set—coil unit / subset". In Table 3, "positioning cycle, number of time slots, and time slot length" collectively determine the number of excitations and available samples that can be completed per unit time; "excitation method" includes forms such as unit polling or subset polling, used to balance coverage and distinguishability; "frequency set" is used to improve electromagnetic response differentiation under different soil electrical properties and interference backgrounds; "coil unit / subset" specifies the coil object to be excited in each time slot.

[0219] Table 3 provides three typical configuration examples: the first is the conventional unit polling mode, the second is the subset polling mode, and the third is the interference segment enhancement mode. Using the configuration methods shown in Table 3, the control terminal can switch the frequency set, adjust the time slot length, or switch the coil subset when the matching residual exceeds the threshold, thereby achieving "adaptive positioning excitation triggered by the matching residual," and ensuring that this adaptive process has a clear engineering parameter basis and is reproducible.

[0220] It should be noted that this embodiment will explain the coarse-to-fine search and interpolation for solving the electromagnetic feature library:

[0221] The step size for discrete location points in the electromagnetic feature library can be 1–5 m. If the estimated location falls between discrete points, linear interpolation or spline interpolation can be performed on the predicted feature vector. The matching solution can be coarse-to-fine: first, search with a step size of 2 m to obtain coarse candidates, then refine within the neighborhood with a step size of 0.2 m. Example: the minimum coarse candidate value is 38 m, and after refinement... and calculate , , Entering the fusion phase.

[0222] It should be noted that the selection, calibration, and interpretation of slippage and tension compensation parameters will be explained in this embodiment:

[0223] Reference Incremental Threshold It affects the sensitivity to slipping. Figure 7 Displayed hour, Increase Reduce. Example: ,but ; ,but The tension compensation coefficient can be obtained by fitting the calibration section. Figure 8 This indicates that the compensation factor decreases as tension increases, thus preventing excessive displacement propagation in high-load sections.

[0224] It should be noted that, in this embodiment, the continuity criteria and hysteresis of residual-triggered adaptive excitation will be explained:

[0225] To avoid boundary jitter, continuous [method / approach] can be used. Sub-threshold triggering, continuous Second lower Restore default settings. Example: , , , The residual sequence, as described above, can trigger a switch and recover after the residuals stabilize and decrease.

[0226] It should be noted that, in this embodiment, the deployment density of radio frequency verification points, fault tolerance, and reset strategies will be further explained:

[0227] Radio frequency (RF) markers can be installed at each pipe section connection or every two or three pipe sections, with interference sections encrypted. If a read fails, a fault tolerance window can be set to retry; if it still fails, the checkpoint is skipped without affecting other checkpoints. Checkpoints are not only used for segmentation error allocation correction but also for fusion state reset: checkpoints constantly use the fusion positioning result as an anchor point to shorten the recursive drift link.

[0228] It should be noted that this embodiment will provide ablation comparison tests, as shown in Tables 4 and 5:

[0229] Example of parameter settings (unified configuration for ablation tests) Table 4

[0230] Table 4 provides examples of key parameter settings used in the ablation test to ensure the comparability of comparison results for different scheme numbers. Table 4 includes parameters such as sampling period, sliding window length, residual threshold, position uncertainty threshold, reference increment threshold, reference tension, tension compensation coefficient, and RF calibration point spacing. These parameters correspond to the operating conditions of modules such as "electromagnetic matching and fusion", "slippage correction", "tension compensation", "adaptive excitation triggering", and "RF segmentation correction" in this embodiment.

[0231] By fixing the parameters shown in Table 4 during the ablation test, the result deviation caused by "parameter differences" can be eliminated, making the error differences of different schemes in Table 5 more reflective of the contribution of each module to the positioning effect.

[0232] Example of ablation comparison results (Condition B: Load fluctuation / slippage zone, unit: m) Table 5

[0233] Table 5 shows an example of ablation comparison results, which is used to illustrate the changing trend of positioning error indicators when key modules are gradually added under the same working conditions (the example in Table 5 is working condition B: load fluctuation / easy slippage section), thereby reflecting the supporting role of each module in the creative contribution point.

[0234] In Table 5, Scheme S0 is a comparative scheme (without introducing the electromagnetic reference matching link, tension compensation, adaptive excitation, and RF segmentation correction modules of this embodiment); Scheme S1 introduces electromagnetic reference and fusion optimization on this basis (corresponding to ground reference coil array positioning excitation, electromagnetic feature construction and feature library matching, and fusion output); Scheme S2 adds tension compensation on the basis of S1 (reflecting the return tension entering the mileage compensation link); Scheme S3 adds adaptive excitation on the basis of S2 (matching residual exceeding the threshold triggers frequency switching / time slot switching / subset switching); Scheme S4 ​​adds RF segmentation correction on the basis of S3 (using RF markers as verification points and performing error allocation correction on the mileage increment sequence within the segment).

[0235] Table 5 shows the "mean horizontal error, horizontal error P95, and maximum value," which represent normal accuracy, upper bound of stability, and extreme peak value, respectively. As can be seen from Table 5, the error indicators show a gradual downward trend as key modules are gradually added, indicating that these modules are not simply superimposed, but rather make measurable contributions to suppressing cumulative errors and reducing peak error values ​​under load fluctuations and slippage conditions. Specifically, the tension compensation module further reduces errors in slippage sections, the adaptive excitation module improves the recognizability of subsequent sampling when matching degrades, and the RF segment correction module constrains long-segment cumulative errors, further reducing the maximum error value and thus improving the engineering usability of the trajectory results.

[0236] It should be noted that, for reference Figure 1 As shown, this embodiment provides a trenchless power pipeline laying device for obtaining the underground trajectory of the pullback head and the power pipeline during directional drilling, borehole enlargement, and pullback laying of power pipelines. The device includes a directional drilling unit, a traction pullback unit, a pipe supply unit, a pullback head, and a control terminal. The traction pullback unit includes a pullback winch and a traction cable. The pullback winch drives the traction cable to pull the pullback head back the power pipeline. The pipe supply unit is used to guide, direct, and support the power pipeline to facilitate the pullback laying operation.

[0237] The tractor unit is equipped with a positioning probe assembly, which includes at least a triaxial receiving coil group, an inertial measurement unit, a mileage measurement unit, and a tension acquisition unit. The triaxial receiving coil group collects electromagnetic response signals generated by the excitation of the ground reference coil array; the inertial measurement unit collects inertial measurement data related to the tractor unit's attitude; the mileage measurement unit collects mileage measurement data during the tractor unit's return journey; and the tension acquisition unit collects tractor unit tension data during the return journey. The positioning probe assembly may also include a radio frequency (RF) reading module for reading RF markers located at the connection points of power pipeline sections to form verification point information. The positioning probe assembly is connected to the control terminal via a cable-fed link. This cable-fed link is preferably located inside the traction cable or laid parallel to the traction cable, and is electrically connected to the positioning probe assembly via a pressure-resistant and waterproof connector to adapt to mud, moisture, and pressure fluctuation environments and improve connection reliability.

[0238] The device also includes a ground reference coil array and a coil drive assembly. The ground reference coil array is deployed on the ground along the designed route of the power pipeline and consists of multiple coil units. The coil drive assembly is electrically connected to the ground reference coil array and is used to apply calibration and positioning excitations to the ground reference coil array according to a preset coded timing sequence, thereby providing identifiable reference information during construction. A control terminal is connected to both the coil drive assembly and the positioning probe assembly. The control terminal receives electromagnetic induction measurement data, inertial measurement data, mileage measurement data, and tension data output by the positioning probe assembly, and performs feature construction, matching operations, and sliding window fusion optimization based on the calibration parameter set and electromagnetic feature library. It outputs the fused positioning result of the tractor unit, deviation prompts or control commands, and positioning quality indicators.

[0239] In this embodiment, the laying and retrieval of the traction cable can be achieved using a winch-type cable laying and retrieval device. This device can draw upon the cable laying control methods used in ship hydrological and geological survey winches to achieve stable tension control. The pressure-resistant and waterproof connectors can utilize the corrosion-resistant, pressure-resistant, sealing, and reliable locking structures of auxiliary equipment such as deep-sea general-purpose materials and connectors to improve the device's applicability in trenchless construction environments. Through the above structural configuration, the device in this embodiment can complete reference excitation, data acquisition, matching, and fusion calculation during the back-hauling laying process, thereby obtaining the positioning trajectory of the trenchless laying of power pipelines and meeting the requirements for quality recording and risk warning during the construction process.

[0240] It should be noted that the embodiments of the present invention have better implementability and are not intended to limit the present invention in any way. Any person skilled in the art may use the above-disclosed technical content to change or modify it into equivalent effective embodiments. However, any modifications or equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A method for trenchless laying and positioning of power pipelines, characterized in that, include: S1, deploy a ground reference coil array on the ground along the designed route of the power pipeline to be laid, and establish a ground coordinate benchmark; S2, install the positioning probe assembly on the tractor unit and connect the tractor unit to the end of the power pipeline; wherein, the positioning probe assembly includes at least a triaxial receiving coil group, an inertial measurement assembly, a mileage measurement assembly, and a tension acquisition assembly; S3, before the start of back-to-base laying, a mutual calibration process is performed. The mutual calibration process includes at least: applying calibration excitation to the ground reference coil array and collecting calibration response to obtain a calibration parameter set. S4, during the back-laying process, the ground reference coil array is subjected to positioning excitation according to the preset coding sequence, and the positioning probe assembly synchronously collects electromagnetic induction measurement data, inertial measurement data, mileage measurement data and tension data; S5, Based on the calibration parameter set, feature construction is performed on the electromagnetic induction measurement data to obtain an electromagnetic feature vector, and the electromagnetic feature vector is matched with the electromagnetic feature library to obtain the electromagnetic positioning result; S6, Based on the inertial measurement data and the odometer measurement data, obtain the inertial odometer positioning result; S7, perform sliding window fusion optimization based on the electromagnetic positioning result and the inertial odometer positioning result, and output the fused positioning result of the tractor unit; S8, calculate the deviation based on the fused positioning result and the designed route, and output the deviation prompt or control command; S9, record the fusion positioning result and the positioning quality index corresponding to the fusion positioning result.

2. The positioning method according to claim 1, characterized in that, The mutual calibration process includes: selecting coil units in the ground reference coil array as calibration transmitting coils in a preset order during the calibration period, and applying the calibration excitation to the calibration transmitting coils; the triaxial receiving coil group of the positioning probe assembly collects the corresponding calibration response to generate calibration parameters in the calibration parameter set for each coil unit.

3. The positioning method according to claim 2, characterized in that, The calibration parameters include amplitude calibration coefficients. The amplitude calibration coefficient Determined by the following formula: in, The calibration response amplitude acquired by the positioning probe assembly during the calibration period. This is the preset reference amplitude.

4. The positioning method according to claim 3, characterized in that, The feature construction includes: the triaxial electromagnetic response amplitude acquired within a single sampling period. , , Normalization is performed to obtain the normalized electromagnetic eigenvectors. ,satisfy: in, This is a normalized scaling factor.

5. The positioning method according to claim 4, characterized in that, The matching includes minimizing the matching cost function. To obtain the electromagnetic positioning result, and the electromagnetic positioning result includes the estimated position obtained by the matching. ,satisfy: in, For the location variable to be estimated, For the first Normalized electromagnetic eigenvectors for each sampling period, For the electromagnetic feature library at position The predicted feature vector at that location, This represents the number of sampling periods within the sliding window. Furthermore, the estimated location To make the matching cost function The positional variable that achieves its minimum value.

6. The positioning method according to claim 5, characterized in that, The electromagnetic feature library is a table established by creating discrete location points along the designed route, and the predicted feature vector Based on the amplitude calibration coefficient It is generated after updating the electromagnetic feature library.

7. The positioning method according to claim 5, characterized in that, The sliding window fusion optimization includes: based on the matching residual scalar Electromagnetic residual weights are assigned to the electromagnetic positioning results. The electromagnetic positioning results and the inertial odometry positioning results are fused within a sliding window, and the electromagnetic residual weights are... satisfy: Wherein, the matching residual scalar satisfy: in, For the matching cost function according to claim 5 at the estimated position The function value at that point, The number of sampling periods within the sliding window.

8. The positioning method according to claim 7, characterized in that, When the matching residual scalar Exceeding the threshold When the ground reference coil array applies the positioning excitation in a preset coding sequence, the method of application is changed. The change includes at least one or more of the following: switching the excitation frequency set, adjusting the excitation time slot length, or switching the coil unit subset participating in the excitation.

9. The positioning method according to claim 7, characterized in that, The power pipeline is formed by connecting multiple pipe sections, and electronic identification elements are set at at least some of the pipe section connections; when the positioning probe assembly identifies the electronic identification element, the fusion positioning result at the corresponding time is written as a verification point into the sliding window fusion optimization process.

10. A trenchless power pipeline laying device, characterized in that, include: The system includes a directional drilling unit, a traction and pullback unit, a pipe supply unit, a pullback head, and a control terminal; wherein, the traction and pullback unit includes a pullback winch and a traction cable, and the pullback winch is used to drive the traction cable to drive the pullback head to pull back the power pipeline. The tractor unit is equipped with a positioning probe assembly, which includes at least a triaxial receiving coil group, an inertial measurement assembly, a mileage measurement assembly, and a tension acquisition assembly. The device also includes a ground reference coil array and a coil driving component, wherein the coil driving component is used to apply calibration excitation and positioning excitation to the ground reference coil array according to a preset coding timing sequence; The control terminal is communicatively connected to the positioning probe assembly and the coil drive assembly, respectively, and the control terminal is configured to execute the positioning method according to any one of claims 1 to 9; Furthermore, the positioning probe assembly is electrically connected to the control terminal via a pressure-resistant and waterproof connector.

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