Unmanned aerial vehicle-mounted microwave phase difference underground pipeline detection device and method

Abstract

The invention relates to an unmanned aerial vehicle-mounted microwave phase difference underground pipeline detection device and method. The device comprises a microwave phase difference detection system and an unmanned aerial vehicle system, and the microwave phase difference detection system is fixedly installed below an unmanned aerial vehicle rack and comprises a microwave emission source module used for generating microwave signals; the antenna array is formed by arranging five yagi antennas at equal intervals, the antenna in the middle is a microwave transmitting antenna, the antennas which are connected with the microwave transmitting source module and are symmetrically arranged on the two sides are microwave receiving antennas; and the phase difference measurement modules are respectively arranged on two sides of the antenna array and are used for measuring and calculating the phase difference between the microwave signals received by the two receiving antennas. The device depends on an unmanned aerial vehicle system, the position, depth and trend of the underground pipeline can be accurately calculated in combination with the position information of the unmanned aerial vehicle, technical support is provided for an intelligent underground pipe network, and the monitoring and maintenance capability of urban infrastructures can be improved.

Description

Technical Field

[0001] This application relates to the technical field of underground pipeline detection, and particularly to an underground pipeline detection device and method based on airborne microwave phase difference of an unmanned aerial vehicle (UAV). Background Art

[0002] In modern urban construction, utility tunnels have become an important part of urban infrastructure, carrying various pipelines including water supply and drainage, power supply, gas, and communication. According to different materials, pipelines can be divided into types such as steel pipes, concrete pipes, and plastic pipes, and each type of pipeline has its own characteristics in terms of bearing capacity, corrosion resistance, and service life. Against the backdrop of the accelerating urbanization process and the renewal of old infrastructure, the detection and maintenance of underground pipe networks are becoming increasingly important. Especially during the process of urban renewal and expansion, many underground pipelines were built a long time ago and lack complete historical data, making it difficult to trace their locations, states, and health conditions.

[0003] Common methods for underground pipe network detection include ground penetrating radar (GPR). GPR can detect metal and non-metal pipelines through the principle of electromagnetic wave reflection. Through echo imaging, GPR can provide data such as the location information, depth, and shape of underground pipelines, and has good spatial resolution. Traditional GPR devices are mostly cart-mounted or vehicle-mounted and are generally applicable to the detection of various underground pipelines.

[0004] In recent years, UAV technology has developed rapidly and has been widely used in various industries, providing new solutions for underground pipe network detection. Existing UAV platforms usually have a certain load capacity and flight stability, which can meet the requirements of conventional tasks. However, when a ground penetrating radar (GPR) is carried on a UAV for underground pipeline detection, due to the heavy weight and high power consumption of the GPR device, it increases the burden on the UAV, shortens the flight duration, and limits the continuity and coverage of the detection task. Summary of the Invention

[0005] 1. Problems to be Solved Based on this, it is necessary to provide an underground pipeline detection device and method based on airborne microwave phase difference of a UAV that can be lightweight and low-power for the above technical problems.

[0006] 2. Technical Solutions In a first aspect, this application provides an underground pipeline detection device based on airborne microwave phase difference of a UAV. The device includes: a UAV platform, a phase difference detection module, and a two-dimensional linear antenna array module; The UAV platform is used to carry the phase difference detection module and the two-dimensional linear antenna array module; The phase difference detection module is used to stimulate the two-dimensional linear antenna array module to generate the required microwave signal and complete the processing of the received microwave signal. The phase difference detection module is set on the rack base of the UAV platform; The two-dimensional linear antenna array module is used to transmit and receive microwave signals. An angle control module is provided on the unfolded plate of the phase difference detection module. The two-dimensional linear antenna array module is connected to the phase difference detection module through the angle control module. The two-dimensional linear antenna array module includes five miniaturized directional antennas, which are arranged at equal intervals. The four miniaturized directional antennas symmetrically arranged on both sides are microwave receiving antennas for receiving echo signals from the ground. The miniaturized directional antenna arranged in the middle is a microwave transmitting antenna for transmitting microwave signals.

[0007] In one embodiment, the phase difference detection module includes: a radio frequency front and rear terminal submodule, a phase difference solver submodule, an IO control submodule and a power supply submodule; The RF front and rear terminal modules are used to stimulate the microwave transmitting antenna to generate a microwave signal of a required frequency and to collect and amplify the microwave signal received by the microwave receiving antenna, and transmit the signal to the phase difference solver module; The phase difference solver module is used to receive the microwave signal after amplification and filtering, and perform phase acquisition and phase difference calculation; The IO control submodule is used to complete the signal output and positioning of the radio frequency radiation source, as well as the control of other submodules and the interaction with the UAV platform data interface; The power supply submodule is used to provide secondary power supply of different voltages required by each submodule.

[0008] In a second aspect, the present application also provides a method for detecting underground pipelines using microwave phase difference onboard an unmanned aerial vehicle. The method includes: The drone cruises autonomously along the preset route in the preset test area; The two-dimensional linear antenna array module continuously transmits and receives microwave signals vertically downward. The phase difference detection module collects and processes the phase difference signals in real time and determines whether there is a pipeline under the ground. When there is a pipeline under the ground, the drone hovers above the suspected point and rotates horizontally until the extension direction of the pipeline is determined; The drone flies back and forth a short distance perpendicular to the pipeline direction and determines the pipeline diameter based on the voltage peak; The tilt angle of the two-dimensional linear antenna array module is controlled to measure the pipeline depth based on the triangulation positioning method.

[0009] In one embodiment, determining whether there is a pipeline under the ground includes: Get the voltage value of the phase difference output corresponding to the target position; When the voltage value output by the phase difference is greater than the preset voltage threshold, set the target position as a suspected point.

[0010] In one embodiment, determining the pipeline extension direction includes: Controlling the drone to rotate and obtaining the voltage value output by the phase difference corresponding to the microwave receiving antenna; When the voltage values output by the phase differences corresponding to different microwave receiving antennas are greater than the preset voltage threshold, determine that the pipeline extension direction matches the arrangement direction of the two-dimensional linear antenna array module.

[0011] In one embodiment, the method further includes: The drone autonomously flies within the target area according to the set zigzag flight path; The phase detection module continuously operates and synchronously records the drone position and the phase difference signal to form a spatial data set; Construct a three-dimensional data matrix based on the spatial data set and draw a two-dimensional heat map; Calculate the pipeline diameter based on the two-dimensional heat map and the linear double-peak phase difference distribution area and calculate the pipeline burial depth information based on the geometric positioning method.

[0012] In a third aspect, the present application also provides an underground pipeline detection system for airborne microwave phase difference. The system includes: An autonomous cruise setting module for the drone to autonomously cruise in a preset area to be measured according to a preset flight path; A suspected pipeline judgment module for the two-dimensional linear antenna array module to continuously transmit and receive microwave signals vertically downward, the phase difference detection module to collect and process the phase difference signal in real time, and to judge whether there is a pipeline underground; A pipeline extension judgment module for when there is a pipeline underground, the drone hovers above the suspected point and rotates horizontally until the pipeline extension direction is determined; A pipeline diameter judgment module for the drone to fly back and forth a short distance in a direction perpendicular to the pipeline direction and determine the pipeline diameter according to the voltage peak value; A pipeline depth judgment module for controlling the tilt angle of the two-dimensional linear antenna array module and measuring the pipeline depth according to the triangulation method.

[0013] In a fourth aspect, the present application also provides a computer system. The computer system includes a memory and a processor. The memory stores a computer program. When the processor executes the computer program, the following steps are implemented: The drone autonomously cruises in a preset area to be measured according to a preset flight path; The two-dimensional linear antenna array module continuously transmits and receives microwave signals vertically downward, the phase difference detection module collects and processes the phase difference signal in real time, and judges whether there is a pipeline underground; When there are pipelines underground, the UAV hovers above the suspected point and rotates horizontally until the extension direction of the pipeline is determined; The UAV flies back and forth a short distance in a direction perpendicular to the pipeline direction, and determines the pipeline diameter according to the voltage peak value; Control the tilt angle of the two-dimensional linear antenna array module, and measure the pipeline depth according to the triangulation method.

[0014] In a fifth aspect, the present application also provides a computer-readable storage medium. The computer-readable storage medium has a computer program stored thereon, and when the computer program is executed by a processor, the following steps are implemented: The UAV autonomously cruises in a preset area to be measured according to a preset route; The two-dimensional linear antenna array module continuously emits and receives microwave signals vertically downward, the phase difference detection module collects and processes the phase difference signals in real time, and determines whether there are pipelines underground; When there are pipelines underground, the UAV hovers above the suspected point and rotates horizontally until the extension direction of the pipeline is determined; The UAV flies back and forth a short distance in a direction perpendicular to the pipeline direction, and determines the pipeline diameter according to the voltage peak value; Control the tilt angle of the two-dimensional linear antenna array module, and measure the pipeline depth according to the triangulation method.

[0015] In a sixth aspect, the present application also provides a computer program product. The computer program product includes a computer program, and when the computer program is executed by a processor, the following steps are implemented: The UAV autonomously cruises in a preset area to be measured according to a preset route; The two-dimensional linear antenna array module continuously emits and receives microwave signals vertically downward, the phase difference detection module collects and processes the phase difference signals in real time, and determines whether there are pipelines underground; When there are pipelines underground, the UAV hovers above the suspected point and rotates horizontally until the extension direction of the pipeline is determined; The UAV flies back and forth a short distance in a direction perpendicular to the pipeline direction, and determines the pipeline diameter according to the voltage peak value; Control the tilt angle of the two-dimensional linear antenna array module, and measure the pipeline depth according to the triangulation method.

[0016] 3. Beneficial effects With the above device relying on the UAV system, the present application can adapt to complex terrains and large-scale survey requirements, and can accurately calculate the position, depth and orientation of underground pipelines in combination with the position information of the UAV. It is applicable to application scenarios such as urban pipe network census, river sewage pipeline detection, and water supply pipeline inspection. The present invention provides technical support for intelligent underground pipe networks and helps to improve the monitoring and maintenance capabilities of urban infrastructure. Description of the drawings

[0017] Figure 1 Schematic diagram of the structure of an underground pipeline detection device with airborne microwave phase difference in an embodiment; Figure 2 Schematic diagram of the structure of a two-dimensional linear antenna array module in an embodiment; Figure 3 Schematic diagram of the structure of a phase difference detection module in an embodiment; Figure 4 Response diagram of real-time conversion of the phase difference between microwave signals into corresponding analog voltage signals in an embodiment; Figure 5 Flowchart of a method for detecting underground pipelines with airborne microwave phase difference in an embodiment; Figure 6 Schematic calculation diagram of the triangulation method in an embodiment; Figure 7 Flowchart of a method for detecting underground pipelines with airborne microwave phase difference in another embodiment; Figure 8 Block diagram of the structure of an underground pipeline detection device with airborne microwave phase difference in an embodiment; Figure 9 Internal structure diagram of a computer system in an embodiment. Detailed implementation manners

[0018] In order to make the objectives, technical solutions and advantages of the present application clearer and more understandable, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0019] As Figure 1 , Figure 2 and Figure 3 shown, an underground pipeline detection device with airborne microwave phase difference specifically includes: an unmanned aerial vehicle (UAV) platform, a phase difference detection module, and a two-dimensional linear antenna array module.

[0020] The UAV platform is used to carry the phase difference detection module and the two-dimensional linear antenna array module; The phase difference detection module is used to excite the two-dimensional linear antenna array module to generate the required microwave signals and complete the processing of the received microwave signals. The phase difference detection module is arranged on the frame base of the UAV platform; The two-dimensional linear antenna array module is used to transmit and receive microwave signals. An angle control module is provided on the unfolded plate of the phase difference detection module. The two-dimensional linear antenna array module is connected to the phase difference detection module through the angle control module. The two-dimensional linear antenna array module includes five miniaturized directional antennas, which are arranged at equal intervals. The four miniaturized directional antennas symmetrically arranged on both sides are microwave receiving antennas for receiving echo signals from the ground. The miniaturized directional antenna arranged in the middle is a microwave transmitting antenna for transmitting microwave signals.

[0021] The UAV platform consists of a carrier structure, flight control system, positioning module, power system, power supply system, and data transmission system. The carrier structure includes the UAV frame, which is specially equipped with an angle control mechanism to support the fixed and rotating two-dimensional linear antenna array module, ensuring its stability and functionality during flight. The flight control system is used to control the UAV's attitude and flight trajectory, supporting autonomous cruising and hovering operations. The positioning module is used to obtain the UAV's position information, flight altitude, and heading angle to achieve spatial positioning of detection data. The power system is used to provide flight power to ensure that the UAV operates according to the mission trajectory. The power supply system is used to provide a stable power supply for the UAV platform and microwave phase difference detection module. The data transmission system is used to achieve wireless transmission of flight status information and detection data.

[0022] It is worth mentioning that the phase difference detection module and the two-dimensional linear antenna array module are fixedly installed on the ground of the UAV platform frame; the phase difference detection module is fixed on the base of the UAV platform frame; the two-dimensional linear antenna array module is fixed on the unfolding plate of the phase difference detection module using an angle control mechanism; the two-dimensional linear antenna array module is used to transmit and receive microwave signals, and the phase difference detection module is used to excite the two-dimensional linear antenna array module to generate the required microwave signals and complete the processing of the received microwave signals; the UAV platform is used to carry the phase difference detection module and the two-dimensional linear antenna array module to realize rapid automatic detection of underground pipelines.

[0023] The drone-mounted microwave phase-difference underground pipeline detection device, based on a drone system, is adaptable to complex terrain and large-scale surveys. Combined with the drone's location information, it can accurately calculate the location, depth, and direction of underground pipelines. It is suitable for applications such as urban pipe network surveys, river sewage pipeline inspections, and water supply pipeline inspections. This invention provides technical support for intelligent underground pipe networks and helps improve the monitoring and maintenance capabilities of urban infrastructure.

[0024] In one embodiment, Figure 3 As shown, the phase difference detection module includes: RF front and rear terminal submodule, phase difference solver submodule, IO control submodule and power supply submodule; The RF front and rear terminal module is used to excite the microwave transmitting antenna to generate microwave signals of the required frequency, collect and amplify the microwave signals received from the microwave receiving antenna, and transmit the signals to the phase difference resolver module; The phase difference resolver module is used to receive the microwave signals after amplification and filtering, and perform phase acquisition and phase difference calculation; The IO control sub-module is used to complete the signal output and positioning of the RF radiation source, the control of other sub-modules, and the interaction with the data interface of the UAV platform; The power supply sub-module is used to complete the secondary power supply of unequal voltages required by each sub-module.

[0025] In one embodiment, as Figure 2 shown, the two-dimensional linear antenna array module includes five miniaturized directional antennas, which are installed on the rotatable expansion board of the phase difference detection module according to the linear design to form a two-dimensional linear antenna array, realizing the transmission and reception of microwave signals. Specifically, the two-dimensional linear antenna array is composed of five equally spaced miniaturized Yagi antennas. The middle antenna is the microwave transmitting antenna, which is connected to the RF front and rear terminal module and is used to transmit 2.4 GHz microwave signals. The four antennas symmetrically arranged on both sides are microwave receiving antennas, which are used to receive the echo signals from the ground; the array spacing is 1 / 2 of the wavelength λ of the transmitted microwave signal, that is, 62.5 mm.

[0026] Furthermore, the phase difference detection module arranges each sub-module using a miniaturized and integrated design concept to make it compact and achieve area minimization. The phase difference detection module can excite the microwave transmitting antenna in the two-dimensional linear antenna array module to generate the required microwave signals, and can also realize the collection, amplification and processing of the microwave signals from the two-dimensional linear antenna array module, and real-time acquisition of the position signals provided by the UAV platform, so that the collected microwave signals and the geographical location can be synchronized and updated.

[0027] In one embodiment, as Figure 2As shown in the figure, the miniaturized directional antenna in the two-dimensional linear antenna array module adopts a directional microstrip patch Yagi antenna with good gain and easy integration. The antenna is in the shape of an isosceles trapezoid. The Yagi antenna is designed for the 2.35 - 2.55 GHz frequency band. Its physical size is compact. The length of the antenna board is about 100 mm and the width is about 50 mm, which is suitable for being carried by a lightweight unmanned aerial vehicle (UAV). The antennas numbered 11, 12, 13, 14, and 15 are installed along the baselines L1, L2, L3, and L4 to form the azimuth dimension baselines. The baseline L5 is the elevation dimension baseline. The pointing direction of the deployment board where the two-dimensional linear antenna array module is located is the pointing direction of the isosceles trapezoid antenna, that is, the long base is facing the short base. The two-dimensional linear antenna array module is installed under the UAV and is connected to the phase difference detection module through an angle control mechanism. The rotation of the deployment board where the two-dimensional linear antenna array module is located can be realized through the IO control sub-module. In the standby state, the deployment board points vertically to the ground, and the plane of the deployment board is perpendicular to the flight direction of the UAV.

[0028] In one embodiment, the two-dimensional linear antenna array selects a linear array composed of five Yagi antennas, and the whole is arranged in a symmetric structure. The operating frequency range of each antenna matches the output frequency of the RF front and rear terminal sub-module to ensure good directivity and broadband reception ability. The five antennas are installed along the transverse direction of the UAV, and the center spacing between the antennas is set to 1 / 2 of the microwave wavelength at the selected frequency to optimize the phase difference measurement accuracy. In this embodiment, the center spacing of the antennas is about 62.5 mm. Considering the antenna mounting brackets and wiring space, the total transverse width occupied by the entire two-dimensional linear antenna array is about 370 mm.

[0029] As Figure 3 shown in the figure, the RF front and rear terminal sub-module in the phase difference detection module adopts a voltage-controlled oscillator (VCO). The VCO adjusts its output frequency through an external control voltage to meet the requirements of different detection environments and ensure the stability and controllability of the microwave signal. The output signal of the VCO is amplified in power and then radiated to the underground structure through a microwave transmitting antenna. At the same time, the RF front and rear terminal sub-module collects the microwave signal received by the microwave receiving antenna, amplifies and filters it, and then sends it to the phase difference resolver module for processing.

[0030] Furthermore, as Figure 4As shown, the phase difference solution operator module in the phase difference detection module receives the microwave signal after amplification and filtering, and performs phase acquisition and phase difference calculation. Specifically, the phase difference solution operator module includes two phase difference measurement units, which are arranged at both ends of the module and connected to two microwave receiving antennas in the two-dimensional linear antenna array on the corresponding side, respectively, for measuring and calculating the phase difference between the microwave signals received by the two receiving antennas; in this application example, the phase difference measurement unit preferably uses the AD8302 phase detection chip as the core measurement component to achieve high-precision extraction of the phase difference between the receiving antenna signals. The AD8302 has the function of converting the phase difference between the input microwave signals into a corresponding analog voltage signal in real time, and the output voltage linearly responds to the change of the phase difference, which is convenient for subsequent circuit recognition and processing.

[0031] It is worth mentioning that the voltage signal is digitized by the analog-to-digital conversion unit (ADC) in the IO control sub-module and synchronously transmitted to the microcontroller (MCU) for real-time analysis and storage. The IO control sub-module has a timestamp synchronization function to ensure that the phase difference signal, the UAV attitude information, and the position information are recorded and compared under the same time reference to improve data consistency and measurement accuracy. The processed phase difference data, combined with the UAV's position information, flight altitude, antenna rotation angle, and timestamp, is transmitted to the ground receiving terminal through wireless communication. The ground receiving terminal performs synchronous calculations on the received data based on the built-in analysis algorithm to determine the position, burial depth, and orientation of the underground pipeline. The detection results are presented in the data processing system of the ground receiving terminal and are available for the operator to make decisions or further analyze.

[0032] In one embodiment, the power supply sub-module is the secondary power supply unit of the phase difference detection module, providing the required stable voltage and current for the phase difference detection module to ensure the normal operation of each component. The voltage of this module comes from the main power supply of the UAV platform, including a voltage conversion circuit and a power management unit, which can provide multiple regulated outputs according to the requirements of different components. Among them, the RF front and rear terminal sub-module and the phase difference measurement module require a high-stability DC power supply to ensure the signal quality of microwave transmission and the accuracy of phase measurement; the IO control sub-module relies on regulated power supply to ensure the reliability of data transmission and processing.

[0033] In one embodiment, the carrier structure in the UAV platform also includes an angle control mechanism for securing and connecting the deployment plate of the two-dimensional linear antenna array module to the UAV platform, while providing adjustable rotation capability to optimize the detection direction of the microwave signal. The angle control mechanism is controlled by a servo mechanism, and the initial position of its rotation axis is defined as perpendicular to the ground (0°), which can be precisely adjusted within a range of ±45°. By dynamically adjusting the angle, the two-dimensional linear antenna array can be incident on the underground target area at different inclination angles, thereby enhancing the signal coverage range of underground pipelines and optimizing detection accuracy. In addition, this rotation design facilitates the application of triangulation positioning method. By measuring phase difference data at different angles, the buried depth information of the pipeline can be further calculated and derived, thereby improving the spatial positioning capability of the detection device to meet the needs of different detection environments.

[0034] Furthermore, the flight control system includes a terrain following module, which can adjust the flight altitude of the UAV in real time according to the undulations of the ground, ensure that the antenna is always in the optimal working position, and improve the accuracy of signal acquisition. The GPS positioning module provides high-precision positioning data to ensure the stable flight of the UAV and record the flight path, altitude and heading angle, providing accurate location information for subsequent data analysis. The power system drives the UAV to fly, realize functions such as take-off and landing, hovering, steering and cruising, and provide stable platform support. The power supply system provides stable power to the microwave phase difference detection device and various modules of the UAV, and has voltage stabilization, overcurrent and short-circuit protection functions to ensure stable and safe operation of the system. The data transmission system is used to wirelessly transmit flight data and detection information, transmit real-time data and flight status to the ground station, and receive mission instructions to achieve remote control.

[0035] like Figure 5 As shown, in a preferred embodiment of the present invention, a method for detecting underground pipelines based on a microwave phase difference detection module mounted on an unmanned aerial vehicle is proposed, which is suitable for quickly identifying information such as the location, direction, diameter, and burial depth of underground pipelines. The method includes the following steps: S1: The drone cruises autonomously along the preset route in the preset test area; S2: The two-dimensional linear antenna array module continuously transmits and receives microwave signals vertically downward. The phase difference detection module collects and processes the phase difference signals in real time and determines whether there is a pipeline under the ground. S3: When there is a pipeline underground, the drone hovers above the suspected location and rotates horizontally until the pipeline extension direction is determined; S4: The drone flies back and forth for a short distance perpendicular to the pipeline direction, and determines the pipeline diameter based on the voltage peak. S5: Control the tilt angle of the two-dimensional linear antenna array module and measure the pipeline depth based on the triangulation positioning method.

[0036] Among them, before the UAV autonomously cruises along the set route in the designated area to be measured, it is necessary to delimit the area to be detected according to the mission requirements. For example, a piece of open space beside a riverbank is selected as the target area. The operator sets the detection area of the UAV through the designed UAV control interface and sets the route parameters, including flight path, flight height, speed, etc., so that the UAV has the ability of autonomous cruise.

[0037] It is worth mentioning that the method for judging whether there is a pipeline underground is as follows: when the UAV flies uniformly along the riverbank direction according to the set route, under normal background conditions, the voltage value corresponding to the phase difference output remains between about 0.15 V and 0.20 V. When the voltage value output by any group of phase difference measurement modules is higher than the set threshold (such as 0.2 V), the system determines that there may be an underground reflection target at this place. At this time, the signal indicator light at one end lights up, and the current GPS position is immediately recorded as the suspected pipeline point position, and then step S2 is entered; if the output voltage value does not exceed the threshold, step S2 is continued to be executed; Furthermore, when the UAV hovers above the suspected point, the flight control system makes the fuselage rotate horizontally around the vertical axis and ensures that the signal indicator light at one end is always on; when the voltage signals exceeding the threshold (i.e., the phase difference peak value) are output by both the left and right receiving antennas at the same time, it is determined that the arrangement direction of the current two-dimensional linear antenna array is consistent with the direction of the underground pipeline. At this time, the signal indicator lights at both ends light up, so as to identify the direction of the pipeline; the maximum horizontal rotation angle of the UAV is 180°. If the signal indicator light at the other end does not light up during this process, the UAV returns to the starting position and enters step S2. If there is, it enters step S4; Specifically, in the preferred embodiment of the present invention, the basic principle of detecting pipelines according to the phase difference detection is as follows: the two-dimensional linear antenna array module adopts a symmetric balanced array composed of five Yagi antennas. The array includes a central transmitting antenna and two pairs of receiving antennas on both sides of it. The radiation directions of all antennas point to the same direction. During the operation, the transmitting antenna emits microwave signals with a frequency of 2.4 GHz. When these signals encounter the edge of an underground target object (such as a pipeline), reflection and diffraction phenomena will occur, and part of the signals will return and be captured by the receiving antennas. Due to the spatial position difference between the receiving antennas, the received signals will show a phase difference. By measuring and analyzing these phase differences, the position and characteristics of the target object can be determined. The present invention sets a predetermined phase difference threshold. When the phase difference between the receiving antenna pairs reaches this threshold, the existence of the target object can be determined. In particular, when the phase differences between the two pairs of receiving antenna pairs are equal and reach the threshold, it can be determined that there is an underground pipeline at this place.

[0038] After identifying the pipeline's orientation, the drone flies a short distance back and forth perpendicular to the pipeline, recording changes in the phase difference signal along the flight path. When two distinct peaks (P1 and P2) are detected in the phase difference signal, the system determines that these peaks correspond to the pipeline's edges. The horizontal distance between the two points is the pipeline's outer diameter, and the midpoint is the pipeline's center.

[0039] like Figure 6 As shown in the figure, the triangulation positioning method for measuring pipeline depth is as follows: after determining the pipeline point and direction, the current position P3 is recorded, and then the UAV adjusts the two-dimensional linear antenna array to a 45° inclination angle with the heading through the angle control device, and slowly retreats in the direction perpendicular to the pipeline; when the double-peak phase difference signal is detected again, the system confirms that it has passed through the reflection area of the same pipeline again, records the current position P4, and the flight distance is Therefore, according to the triangular geometric relationship, the flight retreat distance D and the antenna incident angle are converted together to calculate the buried depth of the pipeline, where h is the height of the drone from the ground.

[0040] In a preferred embodiment of the present invention, a second method for extracting underground pipeline position, direction, diameter and buried depth information using a drone equipped with a phase difference detection module is provided. Figure 7 It is characterized in that it includes the following steps: S1: The UAV flies autonomously within the target area according to the set zigzag route; S2: The phase detection module continuously works to synchronously record the drone's position and phase difference signals to form a spatial data set; S3: Based on the recorded data, a three-dimensional data matrix is constructed and a two-dimensional heat map is drawn; S4: Based on the two-dimensional thermal map, the linear bimodal phase difference distribution area is the pipeline position and its direction. The distance between them can be analyzed to determine the pipeline diameter, and then the geometric positioning method can be used to calculate the pipeline burial depth information.

[0041] Specifically, before autonomous navigation, the drone first defines the area to be explored based on the mission requirements, such as a clearing near a riverbank. This area is then input into the drone's control system through the mission planning system, and flight parameters, including zigzag route planning, altitude, and speed, are set to ensure full coverage of the area.

[0042] It is worth mentioning that when the drone autonomously flies within the target area along the set zigzag flight path, the phase difference detection module continuously operates, recording the voltage output values of each channel every 5 cm, and simultaneously recording the current GPS coordinates and flight altitude of the drone to form a spatial data set corresponding to voltage - position. The data sampling points are dense to ensure high - precision coverage. Then, based on the recorded data, a three - dimensional data matrix is constructed, where the voltage value serves as the Z - axis, and the X and Y coordinates are the planar position coordinates of the actual flight trajectory points of the drone. A two - dimensional heat map or a three - dimensional surface map is drawn using color gradient to visualize the voltage change trend. The color increases from blue to red, where blue represents a small phase difference (background state), and red indicates an abnormal phase difference mutation, which is usually associated with the reflection points of underground structures.

[0043] Specifically, in the figure, a high - intensity response area (i.e., the red and its surrounding areas) is identified. This area indicates that there may be a reflective structure underground. If the hot spot area shows a continuous linear distribution, it can be further determined as a suspected underground pipeline route; if a bimodal phase difference distribution appears, the pipe diameter can be analyzed by judging the distance between the two peaks; finally, the geometric positioning method can be used to estimate the buried depth information of the pipeline.

[0044] It should be understood that although the steps in the flowcharts involved in the above - mentioned embodiments are shown in sequence according to the arrows, these steps do not necessarily execute in the order indicated by the arrows. Unless there is a clear description in this article, the execution of these steps has no strict order limit, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above - mentioned embodiments may include multiple steps or multiple stages. These steps or stages do not necessarily execute at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be executed alternately or in turn with at least a part of other steps or steps or stages in other steps.

[0045] Based on the same inventive concept, the embodiments of the present application also provide an underground pipeline detection device for the airborne microwave phase difference for implementing the underground pipeline detection method of the airborne microwave phase difference involved above. The solution provided by this device to solve the problem is similar to the solution recorded in the above - mentioned method. Therefore, the specific limitations in one or more embodiments of the underground pipeline detection device for the airborne microwave phase difference provided below can refer to the limitations on the underground pipeline detection method of the airborne microwave phase difference in the above text, and will not be repeated here.

[0046] In one embodiment, as Figure 8As shown, a sub - surface pipeline detection system for an unmanned aerial vehicle (UAV) - borne microwave phase difference is provided, including: an autonomous cruise setting module, a suspected pipeline judgment module, a pipeline extension judgment module, a pipeline diameter judgment module, and a pipeline depth judgment module, where: The autonomous cruise setting module is used for the UAV to autonomously cruise along a preset flight path in a preset area to be measured; The suspected pipeline judgment module is used for the two - dimensional linear antenna array module to continuously transmit and receive microwave signals vertically downward, and the phase difference detection module to collect and process the phase difference signals in real - time, and judge whether there is a pipeline underground; The pipeline extension judgment module is used for when there is a pipeline underground, the UAV hovers above the suspected point and rotates horizontally until the pipeline extension direction is determined; The pipeline diameter judgment module is used for the UAV to fly back and forth a short distance along a direction perpendicular to the pipeline direction, and determine the pipeline diameter according to the voltage peak value; The pipeline depth judgment module is used for controlling the tilt angle of the two - dimensional linear antenna array module and measuring the pipeline depth according to the triangulation method.

[0047] In one embodiment, the suspected pipeline judgment module is further used for: obtaining the voltage value output by the phase difference corresponding to the target position; when the voltage value output by the phase difference is greater than a preset voltage threshold, setting the target position as a suspected point.

[0048] In one embodiment, the pipeline extension judgment module is further used for: controlling the UAV to rotate and obtaining the voltage value output by the phase difference corresponding to the microwave receiving antenna; when the voltage values output by the phase differences corresponding to different microwave receiving antennas are greater than a preset voltage threshold, determining that the pipeline extension direction matches the arrangement direction of the two - dimensional linear antenna array module.

[0049] In one embodiment, the autonomous cruise setting module is further used for: the UAV to autonomously fly in the target area according to a set zig - zag flight path; the phase detection module to continuously work and synchronously record the UAV position and phase difference signals to form a spatial data set; constructing a three - dimensional data matrix based on the spatial data set and drawing a two - dimensional heat map; calculating the pipeline diameter based on the two - dimensional heat map and the linear double - peak phase difference distribution area and calculating the pipeline buried depth information based on the geometric positioning method.

[0050] Each module in the above - mentioned sub - surface pipeline detection method for UAV - borne microwave phase difference can be implemented in whole or in part by software, hardware, and their combination. The above - mentioned modules can be embedded in the processor in the computer system in hardware form or be independent of it, or be stored in the memory in the computer system in software form, so that the processor can call and execute the operations corresponding to the above - mentioned modules.

[0051] In one embodiment, a computer system is provided. This computer system can be a server, and its internal structure diagram can be asFigure 9 As shown in the figure. The computer system includes a processor, a memory, and a network interface connected by a system bus. Among them, the processor of the computer system is used to provide computing and control capabilities. The memory of the computer system includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, computer programs, and a database. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage medium. The database of the computer system is used to store data. The network interface of the computer system is used to communicate with external terminals through a network connection. When the computer program is executed by the processor, it implements a method for detecting underground pipelines with airborne microwave phase difference.

[0052] In one embodiment, a computer system is provided. The computer system can be a terminal, and its internal structure diagram can be as Figure 9 shown in the figure. The computer system includes a processor, a memory, a communication interface, a display screen, and an input device connected by a system bus. Among them, the processor of the computer system is used to provide computing and control capabilities. The memory of the computer system includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage medium. The communication interface of the computer system is used to communicate with external terminals in a wired or wireless manner. The wireless manner can be achieved through WIFI, a mobile cellular network, NFC (Near Field Communication), or other technologies. When the computer program is executed by the processor, it implements a method for detecting underground pipelines with airborne microwave phase difference.

[0053] Those skilled in the art can understand that Figure 9 the structure shown in the figure is only a block diagram of some structures related to the solution of the present application, and does not constitute a limitation on the computer system to which the solution of the present application is applied. The specific computer system may include more or fewer components than those shown in the figure, or combine some components, or have different component arrangements.

[0054] In one embodiment, a computer system is provided, including a memory and a processor. A computer program is stored in the memory, and when the processor executes the computer program, it implements the steps in the above method embodiments.

[0055] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by the processor, it implements the steps in the above method embodiments.

[0056] In one embodiment, a computer program product is provided, including a computer program. When the computer program is executed by the processor, it implements the steps in the above method embodiments.

[0057] It should be noted that the user information (including but not limited to user system information, user personal information, etc.) and data (including but not limited to data for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties.

[0058] Those of ordinary skill in the art can understand that all or part of the processes in the methods of the above embodiments can be completed by instructing relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above methods. Among them, any reference to a memory, database, or other medium used in the embodiments provided in this application can include at least one of non-volatile and volatile memories. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetoresistive random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc. The databases involved in the embodiments provided in this application can include at least one of relational databases and non-relational databases. Non-relational databases can include distributed databases based on blockchain, etc., and are not limited thereto. The processors involved in the embodiments provided in this application can be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, data processing logics based on quantum computing, etc., and are not limited thereto.

[0059] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered to be within the scope described in this specification.

[0060] The above-described embodiments merely represent several implementation manners of the present application. The description thereof is relatively specific and detailed, but it should not be construed as a limitation to the patent scope of the present application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all fall within the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the appended claims.

Claims

1. An underground pipeline detection device for airborne microwave phase difference, characterized in that, The device includes: a UAV platform, a phase difference detection module and a two-dimensional linear antenna array module; The UAV platform is used to carry a phase difference detection module and a two-dimensional linear antenna array module; The phase difference detection module is used to stimulate the two-dimensional linear antenna array module to generate the required microwave signal and complete the processing of the received microwave signal. The phase difference detection module is set on the rack base of the UAV platform; The two-dimensional linear antenna array module is used to transmit and receive microwave signals. An angle control module is provided on the unfolded plate of the phase difference detection module. The two-dimensional linear antenna array module is connected to the phase difference detection module through the angle control module. The two-dimensional linear antenna array module includes five miniaturized directional antennas, which are arranged at equal intervals. The four miniaturized directional antennas symmetrically arranged on both sides are microwave receiving antennas for receiving echo signals from the ground. The miniaturized directional antenna arranged in the middle is a microwave transmitting antenna for transmitting microwave signals.

2. The underground pipeline detection device for airborne microwave phase difference according to claim 1, characterized in that, The phase difference detection module includes: a radio frequency front and rear terminal submodule, a phase difference solver submodule, an IO control submodule and a power supply submodule; The RF front and rear terminal modules are used to stimulate the microwave transmitting antenna to generate a microwave signal of a required frequency and to collect and amplify the microwave signal received by the microwave receiving antenna, and transmit the signal to the phase difference solver module; The phase difference solver module is used to receive the microwave signal after amplification and filtering, and perform phase acquisition and phase difference calculation; The IO control submodule is used to complete the signal output and positioning of the radio frequency radiation source, as well as the control of other submodules and the interaction with the data interface of the UAV platform; The power supply submodule is used to provide secondary power supply of different voltages required by each submodule.

3. A method for detecting underground pipelines by using the microwave phase difference carried by an unmanned aerial vehicle, characterized in that, The method comprises: The drone cruises autonomously along the preset route in the preset test area; The two-dimensional linear antenna array module continuously transmits and receives microwave signals vertically downward. The phase difference detection module collects and processes the phase difference signals in real time and determines whether there is a pipeline under the ground. When there is a pipeline under the ground, the drone hovers above the suspected point and rotates horizontally until the extension direction of the pipeline is determined; The drone flies back and forth a short distance perpendicular to the pipeline direction and determines the pipeline diameter based on the voltage peak; The tilt angle of the two-dimensional linear antenna array module is controlled to measure the pipeline depth based on the triangulation positioning method.

4. The method for detecting underground pipelines by using the microwave phase difference of an airborne drone according to claim 3, characterized in that, The determining whether there is a pipeline under the ground includes: Get the voltage value of the phase difference output corresponding to the target position; When the voltage value of the phase difference output is greater than the preset voltage threshold, the target position is set as a suspected point position.

5. The method for detecting underground pipelines by using the microwave phase difference of an airborne drone according to claim 3, wherein, Determining the pipeline extension direction includes: Control the rotation of the drone and obtain the voltage value of the phase difference output corresponding to the microwave receiving antenna; When the voltage values output by the phase differences corresponding to different microwave receiving antennas are greater than a preset voltage threshold, it is determined that the pipeline extension direction matches the arrangement direction of the two-dimensional linear antenna array modules.

6. The underground pipeline detection method of the airborne microwave phase difference according to claim 5, characterized in that, The method further comprises: The drone flies autonomously within the target area according to a set zigzag route; The phase detection module continuously works and synchronously records the drone's position and phase difference signals to form a spatial data set; Construct a three-dimensional data matrix based on the spatial data set and draw a two-dimensional heat map; Calculate the pipeline diameter based on the two-dimensional heat map and the linear bimodal phase difference distribution area, and calculate the pipeline burial depth information based on the geometric positioning method.

7. An underground pipeline detection system for airborne microwave phase difference, characterized in that, The system includes: An autonomous cruise setting module for the UAV to autonomously cruise along a preset route in a preset area to be measured; A suspected pipeline judgment module for the two-dimensional linear antenna array module to continuously transmit and receive microwave signals vertically downward, and the phase difference detection module to collect and process the phase difference signals in real time and judge whether there is a pipeline underground; A pipeline extension judgment module for the UAV to hover above the suspected point and rotate horizontally until the pipeline extension direction is determined when there is a pipeline underground; A pipeline diameter judgment module for the UAV to fly back and forth a short distance along a direction perpendicular to the pipeline direction and determine the pipeline diameter according to the voltage peak value; A pipeline depth judgment module for controlling the tilt angle of the two-dimensional linear antenna array module and measuring the pipeline depth according to the triangulation method.

8. A computer system, including a memory and a processor, the memory storing a computer program, characterized in that, When the processor executes the computer program, the steps of the method according to any one of claims 1 to 6 are implemented.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, the steps of the method according to any one of claims 3 to 6 are implemented.

10. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by the processor, the steps of the method according to any one of claims 3 to 6 are implemented.

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