Pipe depth measuring device and method

Abstract

The application discloses a pipeline buried depth measuring device and method, which comprises a non-contact distance measuring sensor, a portable intelligent terminal and a data communication module. The application combines the portable intelligent terminal with the non-contact distance measuring sensor, and calibrates the posture of the non-contact distance measuring sensor through the posture detection function of the portable intelligent terminal, so that the non-contact distance measuring sensor keeps a vertical downward horizontal posture during the measurement, thereby reducing the measurement error caused by the inaccurate measurement angle. Meanwhile, during the mobile measurement, the non-contact distance measuring sensor keeps the measurement reference surface stable as much as possible, thereby avoiding the measurement error caused by the change of the equipment height. In addition, the portable intelligent terminal performs stage division based on the mutation point identification and abnormal value elimination based on the statistical characteristics on the collected distance sequence, so as to reduce the influence of the measurement noise on the result, thereby improving the accuracy and reliability of the measurement result.

Description

Technical Field

[0001] This invention relates to the field of depth measurement technology, specifically to a device and method for measuring the burial depth of a pipeline. Background Technology

[0002] With the continuous expansion of urban underground pipeline networks, including gas pipelines, drainage pipelines, and communication pipelines, the quality inspection and safety supervision of underground pipeline construction have become particularly important. Pipeline burial depth is one of the important indicators for evaluating the quality of underground pipeline laying, and its measurement results are directly related to the safety of pipeline operation and the subsequent maintenance work.

[0003] Currently, commonly used methods for measuring pipeline burial depth during engineering construction include manual measurement, total station measurement, and leveling. Manual measurement requires personnel to enter the trench, resulting in low efficiency, poor result stability, and significant safety hazards. While total station measurement offers high accuracy, its results are highly dependent on instrument setup and measurement angles, and are easily affected by uneven ground. Furthermore, the equipment used is expensive, the operation is complex, and it requires highly skilled operators, making it difficult to achieve rapid and convenient measurements. Leveling typically requires a level instrument and measuring rod to obtain elevation differences through multiple measurements to calculate pipeline burial depth. Its process is cumbersome, involves many steps, and demands a smooth measurement environment and standardized operating procedures, similarly failing to meet the needs of rapid measurement and flexible deployment on construction sites.

[0004] In summary, existing methods for measuring pipeline burial depth suffer from low efficiency, poor stability, high cost, and complex procedures, failing to meet the demands for rapid measurement and flexible deployment at construction sites. Furthermore, current technologies generally lack effective control and real-time calibration of the measuring equipment's attitude, making it difficult to ensure the distance measurement direction remains perpendicular to the ground, thus affecting the accuracy of the measurement results. They also lack effective mechanisms for handling random errors in the distance measurement data, resulting in insufficient stability and reliability of the measurement results. Summary of the Invention

[0005] This invention provides a device and method for measuring pipeline burial depth, aiming to overcome the shortcomings of existing pipeline burial depth measurement methods, such as low measurement efficiency, poor stability, high measurement cost, complex measurement process, and insufficient accuracy and reliability of measurement results.

[0006] In a first aspect, embodiments of the present invention provide a pipe burial depth measuring device, comprising:

[0007] A non-contact ranging sensor is used to measure the distance between itself and the target surface in a non-contact manner, and continuously collects the distance at a preset sampling frequency to form a distance sequence;

[0008] A portable smart terminal is provided with an attitude detection unit and a data processing unit; the attitude detection unit is used to acquire the attitude information of the non-contact ranging sensor and determine whether the non-contact ranging sensor meets the horizontal measurement conditions based on the attitude information; the data processing unit also receives the distance sequence and performs stage division based on mutation point identification and outlier removal based on statistical characteristics on the distance sequence to calculate the pipeline burial depth value.

[0009] The data communication module is used to establish data communication between the non-contact ranging sensor and the portable smart terminal.

[0010] As a preferred embodiment of the present invention, the non-contact ranging sensor includes a laser time-of-flight ranging module, a laser triangulation ranging module, an infrared ranging module, or an ultrasonic ranging module.

[0011] As a preferred embodiment of the present invention, the portable smart terminal includes a smartphone, tablet computer, PDA, or portable computing device with attitude detection function.

[0012] In a preferred embodiment of the present invention, the attitude detection unit acquires the attitude information of the non-contact ranging sensor and acquires the comprehensive tilt angle of the non-contact ranging sensor based on the attitude information.

[0013] When the overall tilt angle is less than or equal to a preset attitude threshold, the data processing unit determines that the non-contact ranging sensor meets the horizontal measurement conditions, and outputs an attitude adjustment prompt when the overall tilt angle is greater than the preset attitude threshold.

[0014] Secondly, embodiments of the present invention provide a method for measuring the burial depth of a pipeline, comprising:

[0015] The attitude information of the non-contact ranging sensor is acquired, and the non-contact ranging sensor is calibrated based on the attitude information to maintain the vertically downward horizontal attitude of the non-contact ranging sensor and maintain the stability of the measurement reference plane.

[0016] The non-contact ranging sensor is controlled to move continuously in one direction along a preset measurement path between the top of the unexcavated ground surface and the top of the pipeline, and the height change of the non-contact ranging sensor during the movement is less than a preset height threshold; the non-contact ranging sensor is controlled to continuously collect the distance between itself and the target surface at preset time intervals during the movement to form a distance sequence.

[0017] The distance sequence is divided into stages, abrupt changes are identified in the distance sequence, and transitional data in the distance sequence is removed based on the abrupt changes, thus dividing the distance sequence into the surface measurement stage distance sequence and the pipeline top measurement stage distance sequence.

[0018] Outlier removal and mean calculation are performed on the distance sequences of the surface measurement stage and the distance sequences of the pipeline top measurement stage, respectively, to obtain stable distance values ​​for the surface measurement stage and stable distance values ​​for the pipeline top measurement stage.

[0019] The difference between the stable distance measurement value during the surface measurement stage and the stable distance measurement value during the pipeline top measurement stage is calculated and used as the pipeline burial depth value.

[0020] In a preferred embodiment of the present invention, the step of acquiring the attitude information of the non-contact ranging sensor and calibrating the non-contact ranging sensor based on the attitude information specifically includes:

[0021] The attitude detection unit set in the portable smart terminal acquires the attitude information of the non-contact ranging sensor in real time, and obtains the comprehensive tilt angle of the non-contact ranging sensor based on the attitude information.

[0022] When the overall tilt angle is less than or equal to a preset attitude threshold, an alert signal is output to confirm that the non-contact ranging sensor meets the vertical downward horizontal measurement condition; when the overall tilt angle is greater than the preset attitude threshold, an attitude adjustment alert signal is output.

[0023] As a preferred embodiment of the present invention, identifying abrupt change points in the distance sequence specifically includes:

[0024] Determine the local mean calculation window length and transition data removal width of the distance sequence;

[0025] Traverse the candidate segmentation positions of the distance sequence, and after removing data with a width equal to the width of the transition data, take the candidate segmentation position as the center and calculate the mean difference of the local data before and after each candidate segmentation position within the local mean calculation window.

[0026] The candidate segmentation position with the largest mean difference is selected as the mutation point.

[0027] As a preferred embodiment of the present invention, the step of removing transitional data from the distance sequence based on the mutation point specifically includes:

[0028] Centered on the mutation point, data with a width equal to the width of the transition data are removed, thereby dividing the distance sequence of the surface measurement stage and the distance sequence of the pipeline top measurement stage.

[0029] As a preferred embodiment of the present invention, the outlier removal and mean calculation of the distance sequence of the surface measurement stage and the distance sequence of the pipeline top measurement stage specifically includes:

[0030] Calculate the median and absolute deviation of the median for the distance sequence of the surface measurement stage and the distance sequence of the distance sequence of the pipeline top measurement stage, respectively;

[0031] Based on the absolute deviation of the median, an outlier removal threshold is set, and distance data in each sequence whose absolute deviation of the distance value relative to its stage median is greater than the outlier removal threshold are removed, thus obtaining the effective distance dataset for the surface measurement stage and the effective distance dataset for the pipeline top measurement stage, respectively.

[0032] Calculate the robust mean of the effective distance dataset for the surface measurement stage and the effective distance dataset for the pipeline top measurement stage to obtain the stable distance values ​​for the surface measurement stage and the stable distance values ​​for the pipeline top measurement stage, respectively.

[0033] In a preferred embodiment of the present invention, the control of the non-contact ranging sensor to move continuously in one direction along a preset measurement path between the unexcavated ground surface and the top of the pipeline specifically includes:

[0034] Keep the detection beam of the non-contact ranging sensor vertically downward and maintain a constant moving speed, and control the non-contact ranging sensor to move continuously in one direction along a preset measurement path between the top of the unexcavated ground surface and the top of the pipeline.

[0035] During the movement, the non-contact ranging sensor is controlled to continuously collect the distance between itself and the target surface at a preset sampling frequency, and the timestamp corresponding to each distance data is recorded to form a distance sequence.

[0036] The pipeline burial depth measurement device and method provided in this invention combine a portable smart terminal with a non-contact ranging sensor. The attitude detection function of the portable smart terminal calibrates the attitude of the non-contact ranging sensor, ensuring it maintains a vertically downward horizontal orientation during measurement, thereby reducing measurement errors caused by inaccurate measurement angles. Simultaneously, during the measurement process where the non-contact ranging sensor moves continuously in one direction along a preset measurement path between the unexcavated ground surface and the top of the pipeline, the attitude detection function of the portable smart terminal helps maintain the stability of the measurement reference plane, thus avoiding measurement errors caused by changes in device height. Furthermore, the portable smart terminal performs stage division based on abrupt change point identification and outlier removal based on statistical characteristics on the distance sequence collected by the non-contact ranging sensor to reduce the impact of measurement noise on the results, thereby improving the accuracy and reliability of the measurement results.

[0037] This invention enables rapid measurement of pipeline burial depth through a simple structure and steps without the use of complex measuring instruments. It has the advantages of simple structure, low equipment cost, high measurement efficiency, and accurate and stable measurement results. It is suitable for scenarios such as detecting the burial depth of exposed pipelines during pipeline construction. Attached Figure Description

[0038] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0039] Figure 1 This is a schematic diagram of a pipe burial depth measuring device provided in an embodiment of the present invention;

[0040] Figure 2 A schematic flowchart of a pipeline burial depth measurement method provided in an embodiment of the present invention;

[0041] Figure 3 This is another schematic diagram of a pipeline burial depth measurement method provided by an embodiment of the present invention;

[0042] Figure 4 This is a schematic diagram illustrating the specific operation of the non-contact ranging sensor provided in this embodiment of the invention, which is moved horizontally from above the unexcavated ground surface to above the top of the pipeline. Detailed Implementation

[0043] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0044] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0045] Figure 1 This is a schematic diagram of a pipeline burial depth measuring device provided in an embodiment of the present invention. Without using complex measuring instruments, it achieves rapid measurement of pipeline burial depth through a simple structure, and is suitable for on-site measurement in pipeline excavation inspection, trench construction verification, and underground pipeline maintenance. (Refer to...) Figure 1As shown, the pipeline burial depth measuring device provided in this embodiment of the invention mainly includes a non-contact ranging sensor, a portable smart terminal, and a data communication module.

[0046] In this embodiment, a non-contact ranging sensor is used to measure the distance between itself and the target surface in a non-contact manner, and continuously collects the distance at a preset sampling frequency to form a distance sequence.

[0047] The target surface includes the unexcavated ground surface, the top surface of the pipeline, and the transition area surface between the unexcavated ground surface and the top surface of the pipeline. The transition area surface mainly includes the edge of the excavated trench and other areas.

[0048] Furthermore, the surface measurement stage is the stage where the non-contact ranging sensor measures above the unexcavated surface, the pipeline top measurement stage is the stage where the non-contact ranging sensor measures above the top surface of the pipeline, and the moving measurement stage is the stage where the non-contact ranging sensor moves and measures above the surface of the transition area.

[0049] Non-contact ranging sensors include laser time-of-flight ranging modules, laser triangulation ranging modules, infrared ranging modules, or ultrasonic ranging modules. This embodiment uses a laser time-of-flight ranging module. The light source on this module can be selected in different wavelengths based on the reflection conditions of the measurement site, the measurement distance, and anti-interference requirements. These are primarily visible light or near-infrared wavelengths, such as 650nm, 850nm, 905nm, 940nm, or 1550nm. Different wavelengths are used to adapt to the reflection characteristics of different target surfaces. Visible light facilitates measurement point alignment, while near-infrared wavelengths improve ranging stability and site adaptability. Those skilled in the art can select the appropriate light source wavelength based on measurement requirements.

[0050] Non-contact ranging sensors transmit photoelectric signals to the ground and receive reflected signals reflected from the target surface. They calculate the distance between the sensor and the target surface using the round-trip time of the photoelectric signal and continuously collect the distance data at a preset sampling frequency (e.g., once per second) to form a distance sequence.

[0051] The data communication module is used to establish data communication between the non-contact ranging sensor and the portable smart terminal. The data communication module preferably uses a wired communication method with UART to USB protocol conversion, but it can also be connected to an external Bluetooth communication module, WiFi communication module, or other wired / wireless communication modules to achieve flexible configuration, depending on actual needs. The distance sequence collected by the non-contact ranging sensor is transmitted to the portable smart terminal through the data communication module for data processing, and finally the pipeline burial depth is calculated.

[0052] The portable smart terminal is the core processing unit of this device. It has a built-in attitude detection unit and a data processing unit, enabling attitude detection and possessing strong data processing capabilities. The attitude detection unit acquires the attitude information of the non-contact ranging sensor, and the data processing unit determines whether the sensor meets the horizontal measurement requirements based on this information. The operator then uses this attitude information to calibrate the sensor's horizontal attitude. The data processing unit also receives the distance sequence collected by the non-contact ranging sensor, performs stage division based on abrupt change point identification, and outlier removal based on statistical characteristics, ultimately calculating the pipeline burial depth.

[0053] Portable smart terminals include smartphones, tablets, PDAs (Personal Digital Assistants), or portable computing devices with attitude detection capabilities. This embodiment uses a smartphone, which is small, portable, and widely integrates attitude detection sensors while possessing strong data processing capabilities.

[0054] The attitude detection unit includes a level or other inertial measurement unit (IMU) that can acquire attitude information of the non-contact ranging sensor, such as pitch angle, roll angle, angular velocity, etc., and then obtain the overall tilt angle of the non-contact ranging sensor based on this attitude information.

[0055] The data processing unit determines that the non-contact ranging sensor meets the horizontal measurement conditions when the overall tilt angle is less than or equal to a preset attitude threshold, and outputs an attitude adjustment prompt when the overall tilt angle is greater than the preset attitude threshold. Thus, with calibration by the attitude detection unit on a portable smart terminal, the operator can ensure that the non-contact ranging sensor maintains a vertically downward horizontal attitude and keeps the measurement reference plane stable during the unidirectional continuous movement of the sensor along a preset measurement path between the unexcavated ground surface and the top of the pipeline, and continuously collects the distance between the sensor and the target surface at preset time intervals.

[0056] This device combines a portable smart terminal with a non-contact ranging sensor to create a simple, portable, and highly efficient measurement system. During measurement, the non-contact ranging sensor is initially positioned above the unexcavated ground surface or the top of the pipeline. The portable smart terminal performs attitude calibration on the sensor. After calibration, the distance between the sensor and the unexcavated ground surface or the top of the pipeline is acquired. The sensor is then continuously moved unidirectionally along a preset measurement path between the unexcavated ground surface and the top of the pipeline. During this movement, attitude calibration is performed in real-time via the portable smart terminal, and the distance is continuously collected at a preset sampling frequency to form a distance sequence. The portable smart terminal receives this distance sequence through a data communication module and performs stage division based on abrupt change point identification and outlier removal based on statistical characteristics. Finally, the pipeline burial depth is calculated.

[0057] Reference Figure 2 and Figure 3 As shown, this embodiment of the invention provides a method for measuring the burial depth of a pipeline, which is based on the pipeline burial depth measurement described in the above embodiment, and mainly includes the following steps:

[0058] Step 201: Obtain the attitude information of the non-contact ranging sensor and calibrate the non-contact ranging sensor based on the attitude information.

[0059] In this step, during measurement, the non-contact ranging sensor is first placed on the unexcavated ground surface or above the top of the pipeline. The attitude detection unit in the portable smart terminal acquires the attitude information of the non-contact ranging sensor in real time, and obtains the comprehensive tilt angle of the non-contact ranging sensor based on the attitude information.

[0060] During this process, the comprehensive tilt angle and level calibration indicator icons are displayed in real time on the display interface of the portable smart terminal for easy viewing by the operator.

[0061] When the combined tilt angle Less than or equal to the preset attitude threshold When the portable smart terminal outputs a prompt signal, it confirms that the non-contact ranging sensor meets the vertical downward horizontal measurement condition; when the combined tilt angle Greater than the preset attitude threshold When this happens, the portable smart terminal outputs a posture adjustment prompt signal, and the operator needs to readjust the position of the non-contact ranging sensor.

[0062] This step ensures that the non-contact ranging sensor maintains a vertically downward horizontal orientation throughout the measurement process and keeps the measurement reference plane stable, thereby reducing measurement errors caused by inaccurate measurement angles and changes in equipment height, and ensuring the accuracy and reliability of the measurement results.

[0063] Step 202: Control the non-contact ranging sensor to move continuously in one direction along a preset measurement path between the top of the unexcavated ground surface and the top of the pipeline, and during the movement, the height change of the non-contact ranging sensor is less than a preset height threshold; control the non-contact ranging sensor to continuously collect the distance between itself and the target surface at preset time intervals during the movement, forming a distance sequence.

[0064] In this step, after placing the non-contact ranging sensor on the unexcavated ground surface or above the top of the pipeline and calibrating its horizontal attitude, the sensor is activated for measurement. It should be noted that in this embodiment, the measurement path of the non-contact ranging sensor can be from above the unexcavated ground surface to above the top of the pipeline, or vice versa. The operator can preset the measurement path according to actual measurement needs. In this embodiment, for ease of explanation of the specific operating steps, the following description will only use the measurement path of the non-contact ranging sensor moving from above the unexcavated ground surface to above the top of the pipeline as an example.

[0065] Specific reference Figure 4 As shown, the non-contact ranging sensor is controlled to slowly move from above the unexcavated ground surface along the ground surface direction to above the top of the pipe, and continuously collects the distance between itself and the target surface at preset time intervals during the movement. Preferably, the height change of the non-contact ranging sensor during the movement is less than a preset height threshold, so that it moves while maintaining a basically constant relative height.

[0066] In a preferred embodiment of the present invention, the step of controlling the non-contact ranging sensor to move continuously in one direction along a preset measurement path between the top of the unexcavated ground surface and the top of the pipeline specifically includes the following steps:

[0067] Keep the detection beam of the non-contact ranging sensor vertically downward and maintain a constant moving speed, and control the non-contact ranging sensor to move continuously in one direction along the preset measurement path between the top of the unexcavated ground surface and the top of the pipeline.

[0068] During the movement, the non-contact ranging sensor is controlled to continuously collect the distance between itself and the target surface at a preset sampling frequency, and the timestamp corresponding to each distance data is recorded to form a distance sequence.

[0069] In this embodiment, a laser time-of-flight ranging module is used as an example for detailed description. Those skilled in the art can choose other types of non-contact ranging sensors for measurement. The following operation method is also applicable to other non-contact ranging sensors.

[0070] The laser time-of-flight ranging module emits laser pulses towards the unexcavated ground surface and receives the reflected signals. It calculates the distance between the laser and the unexcavated surface based on the laser's round-trip time, continuously collecting distance data multiple times at preset time intervals (e.g., 1 second). The first... The initial laser ranging value for the second sampling is:

[0071]

[0072] In the formula, Indicates the first The original laser ranging value obtained from the second sampling Represents the speed of light. Indicates the first The round-trip time of a laser pulse from transmission to reception.

[0073] When the laser time-of-flight ranging module is kept basically horizontal and the laser ranging direction is basically vertical, the laser ranging value can be directly used as the vertical distance. However, if a slight tilt of the laser time-of-flight ranging module is considered, then... The vertical distance corresponding to the second sampling can be expressed as:

[0074]

[0075] in, For the first The vertical distance corresponding to the next sample. For the first The overall tilt angle at the time of the second sampling.

[0076] To ensure the accuracy of the measurement results, the distance between the surface and the unexcavated surface needs to be collected multiple times at preset time intervals during this surface measurement phase, forming a distance sequence for the surface measurement phase:

[0077]

[0078] in, Indicates the first stage of surface measurement The vertical distance obtained from the second sampling. This represents the number of sampling points during the surface measurement phase.

[0079] After completing the surface distance measurement, the laser time-of-flight ranging module is slowly moved horizontally from above the unexcavated surface to above the top of the pipeline. During the movement, the attitude detection unit of the portable smart terminal remains active, monitoring the attitude of the laser time-of-flight ranging module in real time.

[0080] To ensure that the surface measurement phase and the pipeline top measurement phase are at the same horizontal reference, the attitude change of the laser time-of-flight ranging module should be controlled to meet the following requirements during the movement:

[0081]

[0082] in, Indicates the first step during the movement. The overall tilt angle at the second sampling point The reference dip angle represents the stage of surface measurement. This indicates the allowed attitude change threshold.

[0083] During the movement, the laser time-of-flight ranging module can continuously collect distance data. However, because the measurement target gradually changes from the ground surface to the edge of the trench, the inside of the trench, or the top of the pipe, the data during this stage usually exhibits abrupt changes or transitional fluctuations. To avoid this data affecting the calculation results, subsequent data processing steps will remove the transitional data during the movement phase.

[0084] Once the laser time-of-flight ranging module moves horizontally above the top area of ​​the pipe, the laser ranging direction is aligned with the top of the pipe. Similarly, to ensure measurement accuracy, the laser time-of-flight ranging module continues to collect distance data multiple times at the same preset time intervals as during the surface measurement phase, and transmits the results to a portable smart terminal. During continuous measurements at the top of the pipe, a distance sequence for the pipe top measurement phase is formed:

[0085]

[0086] in, Indicates the measurement stage at the top of the pipe. The vertical distance obtained from the second sampling. This indicates the number of sampling points during the measurement phase at the top of the pipeline.

[0087] Since the top of the pipeline is located below the ground surface, the distance from the laser time-of-flight ranging module to the top of the pipeline is calculated while maintaining the same horizontal reference. Greater than the distance from the laser time-of-flight ranging module to the ground surface. .

[0088] Through the above operations, as the non-contact ranging sensor moves from above the unexcavated ground surface to above the top of the pipeline, it continuously collects the distance between itself and the target surface, forming a distance sequence:

[0089]

[0090] in, This represents the total number of sampling points. For the first Distance data.

[0091] This distance sequence includes the distance sequence for the surface measurement phase and the distance sequence for the top of the pipeline measurement phase.

[0092] Step 203: Divide the distance sequence into stages, identify abrupt change points in the distance sequence, remove transitional data in the distance sequence based on abrupt change points, and divide the distance sequence into the surface measurement stage distance sequence and the pipeline top measurement stage distance sequence.

[0093] In this step, the data processing unit of a portable smart terminal automatically analyzes the continuously collected distance sequences from the previous steps, identifying abrupt changes between the surface measurement stage and the pipeline top measurement stage. Based on these abrupt changes, transitional data from the moving measurement stage between the two stages is removed, thus dividing the distance sequence into a surface measurement stage distance sequence and a pipeline top measurement stage distance sequence. The surface measurement stage distance sequence is formed by continuously collecting distances between a non-contact ranging sensor and the unexcavated surface, while the pipeline top measurement stage distance sequence is formed by continuously collecting distances between a non-contact ranging sensor and the top of the pipeline. It should be noted that the data in both sequences are the result of removing transitional data from the moving measurement stage, centered on the abrupt change point.

[0094] In a preferred embodiment of the present invention, the step of identifying abrupt change points in the distance sequence specifically includes the following steps:

[0095] Determine the local mean calculation window length and transition data removal width for the distance sequence;

[0096] Traverse the candidate segmentation positions of the distance sequence, and with the candidate segmentation position as the center, remove the data with a width equal to the transitional data. After removing the data with a width equal to the transitional data, calculate the mean difference of the local data before and after each candidate segmentation position within the local mean calculation window.

[0097] The candidate segmentation position with the largest mean difference is selected as the mutation point.

[0098] Specifically, based on the total number of sampling points First, determine the local mean calculation window length, the transition data removal width (the width of data to be removed near the mutation point), and the minimum stage data volume (the minimum amount of data to be retained in each measurement stage).

[0099] Among them, the local mean calculation window length for:

[0100]

[0101] Transition data removal width for:

[0102]

[0103] Minimum stage data volume for:

[0104]

[0105] Because the distance measuring object changes when the non-contact ranging sensor moves from above the ground to above the top of the pipe, obvious abrupt changes often occur in the continuous distance sequence. The data processing unit finds the abrupt change points by comparing the difference in local means before and after removing transitional data at the candidate segmentation position, centered on the candidate segmentation position.

[0106] For candidate segmentation positions Calculate the mean of the front local mean calculation window after removing transitional data:

[0107]

[0108] Then calculate the mean of the back local mean calculation window after removing transitional data:

[0109]

[0110] The intermediate interval g is used to avoid transitional data during the moving measurement phase, and half of the transitional data is removed before and after the candidate segmentation position.

[0111] Therefore, candidate segmentation positions The difference between the mean values ​​of the anterior and posterior local mean calculation windows is:

[0112]

[0113] The data processing unit traverses all candidate segmentation positions within the effective search range and selects the point with the largest difference between the mean values ​​of the front and rear local mean calculation windows as the mutation point:

[0114]

[0115] in, These are the detected candidate segmentation locations.

[0116] Furthermore, identify the mutation point. Subsequently, in order to avoid the influence of transitional data generated during the non-contact distance measurement phase on the burial depth calculation, a certain width of data needs to be removed from the distance sequence centered on the point of change.

[0117] In a preferred embodiment of the present invention, removing transitional data from the distance sequence based on abrupt change points specifically includes:

[0118] Centered on the mutation point, data with a width of transitional data are removed, thereby dividing the distance sequence of the surface measurement stage and the distance sequence of the pipeline top measurement stage.

[0119] Specifically, the effective dataset for the surface measurement phase is:

[0120]

[0121] The valid dataset for the top-of-pipe measurement phase is as follows:

[0122]

[0123] in, Corresponding to the distance sequence data of the surface measurement phase, The distance sequence data corresponding to the measurement stage at the top of the pipeline.

[0124] When the amount of data retained in a certain stage is insufficient, a forced proportional segmentation method will be adopted, using the first 40% of the data as the distance sequence data for the surface measurement stage and the last 40% of the data as the distance sequence data for the pipeline top measurement stage.

[0125]

[0126]

[0127] Step 204: Perform outlier removal and mean calculation on the distance sequences of the surface measurement stage and the pipeline top measurement stage, respectively, to obtain the stable distance measurement values ​​of the surface measurement stage and the stable distance measurement values ​​of the pipeline top measurement stage.

[0128] In this step, after removing transitional data, the distance series is divided into the surface measurement stage distance series and the pipeline top measurement stage distance series. Outlier removal is then performed on both stages. After outlier removal, robust means are calculated for the remaining valid data in the distance series of these two stages.

[0129] In a preferred embodiment of the present invention, the steps of outlier removal and mean calculation for the distance sequences of the surface measurement stage and the distance sequences of the pipeline top measurement stage specifically include the following steps:

[0130] Calculate the median and absolute deviation of the median for the distance sequence of the surface measurement stage and the distance sequence of the pipeline top measurement stage, respectively;

[0131] An outlier removal threshold is set based on the absolute deviation of the median. Distance data in each sequence whose absolute deviation of the distance value relative to its stage median is greater than the outlier removal threshold are removed, resulting in valid distance datasets for the surface measurement stage and the pipeline top measurement stage, respectively.

[0132] Calculate the robust mean of the effective distance datasets for the surface measurement stage and the pipeline top measurement stage to obtain the stable distance values ​​for the surface measurement stage and the pipeline top measurement stage, respectively.

[0133] In this embodiment, a distance sequence dataset at any stage is used as an example:

[0134]

[0135] in, This represents the number of distance data points in the distance sequence. For the first Distance data.

[0136] First, calculate the median of the distance sequence for that stage:

[0137]

[0138] Then calculate the absolute deviation of each distance data point relative to the stage median:

[0139]

[0140] Then, the median of the absolute deviation is calculated as a robust scalar parameter for MAD:

[0141]

[0142] When a certain distance data is greater than the outlier removal threshold, it satisfies the condition. When this happens, the data is identified as abnormal and removed. In this embodiment, an outlier removal threshold is set. Set as It is 2.5 times that of the actual situation. Those skilled in the art can set other appropriate thresholds according to the actual situation.

[0143] After removing outliers, a robust mean is calculated for the remaining valid data. Let the distance to the valid dataset at any stage after removing outliers be:

[0144]

[0145] The stable ranging value for this stage is:

[0146]

[0147] Among them, | | represents the number of valid data points in the valid dataset at this stage.

[0148] Based on the above calculation process, for the surface measurement stage, the stable distance measurement value for the surface measurement stage is obtained:

[0149]

[0150] For the measurement phase at the top of the pipeline, the stable distance measurement value for this phase is obtained:

[0151]

[0152] in, For the effective dataset of distances in the surface measurement phase, | | represents the number of valid data points in the effective distance dataset during the surface measurement phase. This is a valid dataset for measuring distances at the top of the pipe. This represents the number of valid data points in the effective dataset during the measurement phase at the top of the pipeline.

[0153] Step 205: Calculate the difference between the stable distance measurement value during the surface measurement stage and the stable distance measurement value during the top of the pipeline measurement stage, and use it as the pipeline burial depth value.

[0154] In this step, after calculating the stable distance measurement values ​​for the surface measurement stage and the pipeline top measurement stage respectively through the above steps, and assuming the non-contact distance sensor maintains the same horizontal reference, the burial depth of the pipeline top relative to the ground surface is the difference between the stable distance measurement values ​​of the two stages:

[0155]

[0156] Finally, the portable smart terminal stores or exports the calculated pipeline burial depth results for subsequent project verification.

[0157] In summary, the pipeline burial depth measurement device and method described in this embodiment have the following effective effects:

[0158] (1) The present invention uses a non-contact ranging sensor for measurement, especially the laser time-of-flight ranging module, which makes the entire measuring device simple in structure, small in size, low in cost, easy to carry, and able to meet the needs of rapid detection at the construction site.

[0159] (2) The present invention utilizes the attitude detection unit built into the portable smart terminal to realize the attitude detection of the device, making the distance measurement process more convenient and reducing the dependence on external auxiliary equipment.

[0160] (3) By combining the posture detection unit built into the portable smart terminal, the present invention can manually monitor and calibrate the posture of the two-stage measurement process, so as to keep the measuring device at the same horizontal reference during the two-stage measurement process, thereby effectively reducing the measurement error caused by the change of equipment height.

[0161] (4) The present invention uses differential distance measurement to calculate the burial depth of the pipeline, which can reduce the impact of system error on the measurement results and thus improve the accuracy of the burial depth calculation.

[0162] (5) The present invention improves the reliability of the overall measurement results by sampling and filtering the ranging data multiple times.

[0163] In the above embodiments of the present invention, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0164] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A device for measuring the burial depth of a pipeline, characterized in that, It includes: A non-contact ranging sensor is used to measure the distance between itself and the target surface in a non-contact manner, and continuously collects the distance at a preset sampling frequency to form a distance sequence; A portable smart terminal is provided with an attitude detection unit and a data processing unit; the attitude detection unit is used to acquire the attitude information of the non-contact ranging sensor; the data processing unit determines whether the non-contact ranging sensor meets the horizontal measurement conditions based on the attitude information; the data processing unit also receives the distance sequence and performs stage division based on mutation point identification and outlier removal based on statistical characteristics on the distance sequence to calculate the pipeline burial depth value. The data communication module is used to establish data communication between the non-contact ranging sensor and the portable smart terminal.

2. The apparatus according to claim 1, characterized in that, The non-contact ranging sensor includes a laser time-of-flight ranging module, a laser triangulation ranging module, an infrared ranging module, or an ultrasonic ranging module.

3. The apparatus according to claim 1, characterized in that, The portable smart terminal includes smartphones, tablets, PDAs, or portable computing devices with attitude detection capabilities.

4. The apparatus according to claim 1, characterized in that, The attitude detection unit acquires the attitude information of the non-contact ranging sensor and obtains the comprehensive tilt angle of the non-contact ranging sensor based on the attitude information. When the overall tilt angle is less than or equal to a preset attitude threshold, the data processing unit determines that the non-contact ranging sensor meets the horizontal measurement conditions, and outputs an attitude adjustment prompt when the overall tilt angle is greater than the preset attitude threshold.

5. A method for measuring the burial depth of a pipeline, characterized in that, It includes: The attitude information of the non-contact ranging sensor is acquired, and the non-contact ranging sensor is calibrated based on the attitude information to maintain the vertically downward horizontal attitude of the non-contact ranging sensor and maintain the stability of the measurement reference plane. The non-contact ranging sensor is controlled to move continuously in one direction along a preset measurement path between the top of the unexcavated ground surface and the top of the pipeline, and the height change of the non-contact ranging sensor during the movement is less than a preset height threshold; the non-contact ranging sensor is controlled to continuously collect the distance between itself and the target surface at preset time intervals during the movement to form a distance sequence. The distance sequence is divided into stages, abrupt changes are identified in the distance sequence, and transitional data in the distance sequence is removed based on the abrupt changes, thus dividing the distance sequence into the surface measurement stage distance sequence and the pipeline top measurement stage distance sequence. Outlier removal and mean calculation are performed on the distance sequences of the surface measurement stage and the distance sequences of the pipeline top measurement stage, respectively, to obtain stable distance values ​​for the surface measurement stage and stable distance values ​​for the pipeline top measurement stage. The difference between the stable distance measurement value during the surface measurement stage and the stable distance measurement value during the pipeline top measurement stage is calculated and used as the pipeline burial depth value.

6. The method according to claim 5, characterized in that, The process of acquiring the attitude information of the non-contact ranging sensor and calibrating the non-contact ranging sensor based on the attitude information specifically includes: The attitude detection unit set in the portable smart terminal acquires the attitude information of the non-contact ranging sensor in real time, and obtains the comprehensive tilt angle of the non-contact ranging sensor based on the attitude information. When the overall tilt angle is less than or equal to a preset attitude threshold, an alert signal is output to confirm that the non-contact ranging sensor meets the vertical downward horizontal measurement condition; when the overall tilt angle is greater than the preset attitude threshold, an attitude adjustment alert signal is output.

7. The method according to claim 5, characterized in that, The identification of mutation points in the distance sequence specifically includes: Determine the local mean calculation window length and transition data removal width of the distance sequence; Traverse the candidate segmentation positions of the distance sequence, and after removing data with a width equal to the width of the transition data, take the candidate segmentation position as the center and calculate the mean difference of the local data before and after each candidate segmentation position within the local mean calculation window. The candidate segmentation position with the largest mean difference is selected as the mutation point.

8. The method according to claim 7, characterized in that, The step of removing transitional data from the distance sequence based on the mutation point specifically includes: Centered on the mutation point, data with a width equal to the width of the transition data are removed, thereby dividing the distance sequence of the surface measurement stage and the distance sequence of the pipeline top measurement stage.

9. The method according to claim 5, characterized in that, The process of outlier removal and mean calculation for the distance sequences of the surface measurement stage and the distance sequences of the pipeline top measurement stage specifically includes: Calculate the median and absolute deviation of the median for the distance sequence of the surface measurement stage and the distance sequence of the distance sequence of the pipeline top measurement stage, respectively; Based on the absolute deviation of the median, an outlier removal threshold is set, and distance data in each sequence whose absolute deviation of the distance value relative to its stage median is greater than the outlier removal threshold are removed, thus obtaining the effective distance dataset for the surface measurement stage and the effective distance dataset for the pipeline top measurement stage, respectively. Calculate the robust mean of the effective distance dataset for the surface measurement stage and the effective distance dataset for the pipeline top measurement stage to obtain the stable distance values ​​for the surface measurement stage and the stable distance values ​​for the pipeline top measurement stage, respectively.

10. The method according to claim 5, characterized in that, The control of the non-contact ranging sensor to move continuously in one direction along a preset measurement path between the top of the unexcavated ground surface and the top of the pipeline specifically includes: Keep the detection beam of the non-contact ranging sensor vertically downward and maintain a constant moving speed, and control the non-contact ranging sensor to move continuously in one direction along a preset measurement path between the top of the unexcavated ground surface and the top of the pipeline. During the movement, the non-contact ranging sensor is controlled to continuously collect the distance between itself and the target surface at a preset sampling frequency, and the timestamp corresponding to each distance data is recorded to form a distance sequence.

Images