Method for scanning detection by using low-frequency electromagnetic resonance

Abstract

The invention discloses a method for carrying out scanning detection by utilizing low-frequency electromagnetic resonance, which comprises the following steps of: propagating an electromagnetic beam formed by condensing a geomagnetic field along a straight line, generating resonance scattering when the electromagnetic beam encounters a substance interface in the propagation process, and realizing positioning detection according to scattering boundary magnetic anomaly caused by the resonance scattering. According to the invention, the probes of different specifications can be used to realize detection of the depth of 0.1-300 m, and drilling verification is carried out for many times in the detection of underground roadways and goaf; for detection of tiny flaws of cultural relics and engineering structures, holes with the size of 1 cm and the like can be described through the amplification probe, and cracks with the width smaller than 1 cm can be accurately positioned; horizontal scanning detection of objects including cultural relics on the ground is realized, and the internal structure of the detected object is accurately scanned; the inherent low-frequency resonance electromagnetic wave of the object is utilized, the material type, the attribute shape and the material of the hidden object can be determined, all-directional detection can be carried out, and self-recheck verification can be realized.

Description

Technical Field

[0001] This invention relates to the field of geomagnetic detection technology, and in particular to a method for scanning detection using low-frequency electromagnetic resonance. Background Technology

[0002] In engineering exploration, the detection of underground concealed works is a primary focus and challenge for various detection equipment and technologies. However, for non-destructive testing of the internal structures of above-ground objects, including buildings and cultural relics, the available methods and technologies are limited. Existing radar and flaw detectors cannot achieve deep and accurate detection of surface objects. Similarly, existing geophysical methods such as high-density electrical resistivity tomography, micro-motion, and transient electromagnetic methods cannot accurately detect deep underground objects, even within their effective detection range, often only detecting localized anomalies. Currently, engineering exploration cannot achieve scanning detection methods similar to CT scans or MRI.

[0003] Currently, there is no mature and complete technology for non-destructive testing of ground structures and cultural relics. Concrete flaw detection instruments are limited to concrete structures and lack specific methods for soil, rock, and other materials. Ultrasonic detection and radar suffer from severe signal attenuation due to wavelength factors, limiting their detection depth (radar to 3-5 meters, ultrasonic waves even shallower). Commonly used methods for underground detection, such as high-density electrical resistivity tomography, micro-motion, and transient electromagnetic methods, cannot accurately describe the internal structure of structures, and are unable to detect internal cavities and cracks. Electromagnetic and surface wave combined detection technologies and cosmic ray muon imaging technologies have been tested in the detection of ground cultural relics, but their accuracy has limited their widespread application. Overall, there is still no mature technology for non-destructive testing of ground structures and cultural relics. Furthermore, commonly used radar equipment is unsuitable for high-altitude, wall-mounted operations due to its weight.

[0004] Compared to detecting above-ground structures, the methods for detecting concealed underground objects are relatively diverse, but technical bottlenecks still exist, mainly concerning detection depth and accuracy. For objects deeper than 5 meters, current detection methods—radar, various electrical methods, magnetic methods, acoustic waves, and even sonar—cannot achieve accurate detection. The main reason is the severe attenuation of artificially emitted detection waves underground, and the significant electromagnetic interference at the detection site. Currently, the problems of signal attenuation and interference cannot be technically solved.

[0005] To scan and detect objects on or below ground, the problem of fine detection must first be solved. Only by improving the detection accuracy to the centimeter level can the object be scanned. Secondly, the problem of horizontal detection must be solved. Only by achieving horizontal detection of objects on the ground can the problem of omnidirectional scanning be solved. Summary of the Invention

[0006] This invention provides a low-frequency electromagnetic wave resonant scanning detection technology, which solves the aforementioned industry problems and accurately realizes horizontal and vertical scanning detection, achieving resonant scanning detection of objects above and below ground similar to CT technology.

[0007] The method for scanning detection using low-frequency electromagnetic resonance includes the following steps: The electromagnetic beam formed by the condensation of the Earth's magnetic field propagates in a straight line. When the electromagnetic beam encounters a material interface during propagation, it generates resonant scattering. The location detection is achieved by using the magnetic anomaly at the scattering boundary caused by the resonant scattering.

[0008] Alternatively, a scanning detection method using low-frequency electromagnetic resonance can be used, including the following steps: using a horizontal probe to concentrate the geomagnetic field into a beam, the formed electromagnetic beam propagates in a straight line, and when it encounters a material interface, it generates resonant scattering. The resonant scattering causes magnetic anomalies at the scattering boundary, and the location detection is achieved by detecting the position of the magnetic anomaly.

[0009] Alternatively, a scanning detection method using low-frequency electromagnetic resonance includes the following steps: using a horizontal probe to concentrate the Earth's magnetic field into a beam, the resulting electromagnetic beam propagates in a straight line, and generates resonant scattering when it encounters different material interfaces. By applying the resonant frequencies of different materials, the material being detected is induced to resonate and generate resonant scattering, thereby determining the type and properties of the material being detected.

[0010] Furthermore, a horizontal probe is used to concentrate the geomagnetic field at the detection point and form a horizontal electromagnetic beam.

[0011] Furthermore, when the electromagnetic beam encounters the interface of different magnetoresistive materials on the propagation path, it will generate low-frequency electromagnetic wave resonant scattering. The different low-frequency electromagnetic wave resonant scattering patterns are conical and cause magnetic anomalies at the scattering boundary. The magnetic anomalies can be detected by cutting magnetic field lines.

[0012] Furthermore, the method of detecting magnetic anomalies by cutting magnetic field lines involves using the angle of low-frequency electromagnetic wave resonant scattering by a horizontal probe. By applying control, the following equation is obtained: Wherein, L is the distance from the horizontal probe to the anomaly point during detection, and H is the depth of the calculated interface.

[0013] Furthermore, the angle of resonant scattering of low-frequency electromagnetic waves by a horizontal probe is utilized. To control and make , or .

[0014] Furthermore, different material interfaces have different resonant frequencies.

[0015] Furthermore, when using a horizontal probe for scanning detection, the horizontal probe is placed on the surface of the object to be detected, and a scanning point is formed at a spacing of 5cm-100cm for scanning. The interface depth of each scanning point is calculated. The interface detected by each detection point consists of multiple layers. Then, based on the interface depth of each detection point, the structural shape inside the object surface is outlined, and the material type between each interface layer is determined based on the material frequency signal characteristics of the material.

[0016] This application utilizes probes of different specifications to achieve depths ranging from 0.1 to 300 meters, and has been verified through multiple drilling operations in underground tunnels and mined-out areas. For detecting minute flaws in cultural relics and engineering structures, the magnified probe can describe cavities as small as 1 cm and accurately locate cracks less than 1 cm wide. It enables horizontal scanning detection of above-ground objects, including cultural relics, accurately revealing the internal structure of the detected objects. Utilizing the inherent low-frequency resonant electromagnetic waves of objects, it can determine the material type, properties, shape, and all-around material detection of concealed objects, and achieve self-verification. Attached Figure Description

[0017] 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.

[0018] Figure 1 This is a schematic diagram illustrating the principle of horizontal depth detection provided by the present invention; Figure 2 This is a schematic diagram of the horizontal probe structure provided by the present invention. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0020] The principles of electromagnetic beam formation, resonant scattering, and depth calculation models are explained in this application as follows.

[0021] Electromagnetic beam formation principle: The Earth's magnetic field can be approximated as homogeneous and static in space. According to relevant theories, it can be concentrated into a beam due to the condensation effect and propagate in a straight line in the form of an electromagnetic beam. This is the foundation of the entire technology. The powerful horizontal probe forms a horizontal electromagnetic beam at the detection point based on this characteristic of the Earth's magnetic field, enabling the electromagnetic beam to serve as a detection medium, propagate in space, and interact with the object being measured.

[0022] Resonant scattering principle: When an electromagnetic beam encounters an interface of different magnetoresistance materials along its propagation path, low-frequency electromagnetic wave resonant scattering occurs. From an electromagnetic perspective, the difference in magnetoresistance between different materials leads to changes in electromagnetic properties, interfering with the propagation of electromagnetic waves at the interface. According to the resonance principle, resonance occurs when the external excitation frequency is close to or equal to the natural frequency of the material or system. At this time, the energy of the electromagnetic beam interacts with the material, producing strong scattering, and the scattering is cone-shaped, generating magnetic anomalies at the scattering boundary.

[0023] Reference Figure 1 Deep computational model: When an electromagnetic beam encounters the interface between different objects, it will generate low-frequency electromagnetic wave resonant scattering. The shape of the resonant scattering is cone-shaped according to actual tests. It causes magnetic anomalies at the scattering boundary, which can be detected by cutting magnetic field lines.

[0024] Due to the angle of low-frequency electromagnetic wave resonant scattering It can be controlled by a guide probe, and 45° or 22.5° are typically selected for vertical ground detection. During detection, the distance L from the probe to the anomaly point is measured and then calculated using trigonometric functions. The depth H of the interface is calculated. In horizontal scanning detection, the following is generally selected: ,or The horizontally enhanced probe can magnify defects within the structure of an object by two to four times, thereby improving the accuracy of the detection.

[0025] In actual exploration, depending on the type of underground material, different material resonant frequencies can be used for specific material exploration, that is, different object frequency (the inherent resonant electromagnetic frequency of the object) signal modes can be used for scanning.

[0026] For example, in the structural exploration of an ancient pagoda, three exploration modes were employed: a cavity mode, a Tang Dynasty brick mode, and a soil-fill mode. These modes utilized the electromagnetic waves generated by the material frequencies of the cavities, Tang Dynasty bricks, and plain soil, respectively, to induce their inherent resonant electromagnetic waves. This is because different objects possess different electromagnetic properties and inherent frequencies (the inherent frequencies of different materials vary considerably and can be measured using instruments). When the frequency of the applied electromagnetic excitation matches the inherent frequencies of these objects, a low-frequency resonance phenomenon occurs. By detecting the electromagnetic waves generated by this resonance or the resulting magnetic anomalies, the existence, location, and distribution of objects can be determined, such as confirming the presence of cavities, the distribution of Tang Dynasty bricks, and the soil-fill within the pagoda.

[0027] During scanning and detection, a horizontal probe is placed on the surface of the object to be detected. Depending on the accuracy requirements, scanning is performed at different intervals from 5cm to 100cm. The detection process for each scanning point is the same, and the depth of different interfaces needs to be calculated. The interfaces detected at each detection point can be multiple layers. Then, based on the data of each detection point, the structural shape within the object surface is outlined, and the material type between each interface is determined based on the material frequency signal characteristics (concrete, fill, voids, cracks, pipe diameter, wood, Tang bricks, rammed earth, etc.).

[0028] Due to the inherent characteristics of the Earth's magnetic field, guiding probes can easily concentrate the magnetic field into an electromagnetic beam underground. However, concentrating the Earth's magnetic field into a horizontal electromagnetic beam presents certain challenges. This invention, by employing a composite coil and composite material structure, enhances the probe's guiding function and successfully achieves the formation of a horizontal electromagnetic beam from the Earth's magnetic field. The horizontal probe's structure, from the inside out, consists of a first magnetic material cylinder 1, a first copper coil 2 surrounding the first magnetic material cylinder 1, a second magnetic material cylinder 3 surrounding the first copper coil 2, a second copper coil 4 surrounding the second magnetic material cylinder coil 3, and a glass outer cover 5 surrounding the second copper coil 4. Excitation leads are respectively provided for the first copper coil 2 and the second copper coil 4. By applying excitation to the first copper coil 2 and / or the second copper coil 4 through the excitation leads, the concentration effect becomes more pronounced.

[0029] Based on the aforementioned fundamental theory, this application proposes to use a horizontal probe to condense the geomagnetic field into a beam. The resulting electromagnetic beam propagates in a straight line and generates resonant scattering when it encounters different material interfaces. The resonant scattering causes magnetic anomalies at the scattering boundary, and the location detection is achieved by detecting the position of the magnetic anomaly.

[0030] The specific plan is as follows: The method for scanning detection using low-frequency electromagnetic resonance includes the following steps: The electromagnetic beam formed by the condensation of the Earth's magnetic field propagates in a straight line. When the electromagnetic beam encounters a material interface during propagation, it generates resonant scattering. The location detection is achieved by using the magnetic anomaly at the scattering boundary caused by the resonant scattering.

[0031] Alternatively, a scanning detection method using low-frequency electromagnetic resonance can be used, including the following steps: using a horizontal probe to concentrate the geomagnetic field into a beam, the formed electromagnetic beam propagates in a straight line, and when it encounters a material interface, it generates resonant scattering. The resonant scattering causes magnetic anomalies at the scattering boundary, and the location detection is achieved by detecting the position of the magnetic anomaly.

[0032] Alternatively, a scanning detection method using low-frequency electromagnetic resonance includes the following steps: using a horizontal probe to concentrate the Earth's magnetic field into a beam, the resulting electromagnetic beam propagates in a straight line, and generates resonant scattering when it encounters different material interfaces. By applying the resonant frequencies of different materials, the material being detected is induced to resonate and generate resonant scattering, thereby determining the type and properties of the material being detected.

[0033] Furthermore, a horizontal probe is used to concentrate the geomagnetic field at the detection point and form a horizontal electromagnetic beam.

[0034] Furthermore, when the electromagnetic beam encounters the interface of different magnetoresistive materials on the propagation path, it will generate low-frequency electromagnetic wave resonant scattering. The different low-frequency electromagnetic wave resonant scattering patterns are conical and cause magnetic anomalies at the scattering boundary. The magnetic anomalies can be detected by cutting magnetic field lines.

[0035] Furthermore, the method of detecting magnetic anomalies by cutting magnetic field lines involves using the angle of low-frequency electromagnetic wave resonant scattering by a horizontal probe. By applying control, the following equation is obtained: Wherein, L is the distance from the horizontal probe to the anomaly point during detection, and H is the depth of the calculated interface.

[0036] Furthermore, the angle of resonant scattering of low-frequency electromagnetic waves by a horizontal probe is utilized. To control and make =2, or .

[0037] Furthermore, different material interfaces have different resonant frequencies.

[0038] Furthermore, when using a horizontal probe for scanning detection, the horizontal probe is placed on the surface of the object to be detected, and a scanning point is formed at a spacing of 1cm-100cm for scanning. The interface depth of each scanning point is calculated. The interface detected by each detection point consists of multiple layers. Then, based on the interface depth of each detection point, the structural shape inside the object surface is outlined, and the material type between each interface layer is determined based on the material frequency signal characteristics of the material.

[0039] This application utilizes probes of different specifications to achieve depths ranging from 0.1 to 300 meters, and has been verified through multiple drilling operations in underground tunnels and mined-out areas. For detecting minute flaws in cultural relics and engineering structures, the magnified probe can describe cavities as small as 1 cm and accurately locate cracks less than 1 cm wide. It enables horizontal scanning detection of above-ground objects, including cultural relics, accurately revealing the internal structure of the detected objects. Utilizing the inherent low-frequency resonant electromagnetic waves of objects, it can determine the material type, properties, shape, and all-around material detection of concealed objects, and achieve self-verification.

[0040] 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 method for scanning detection using low-frequency electromagnetic resonance, characterized in that, Includes the following steps: The electromagnetic beam formed by the condensation of the Earth's magnetic field propagates in a straight line. When the electromagnetic beam encounters a material interface during propagation, it generates resonant scattering. The location detection is achieved by using the magnetic anomaly at the scattering boundary caused by the resonant scattering.

2. A method for scanning detection using low-frequency electromagnetic resonance, characterized in that, The process includes the following steps: using a horizontal positioning and guiding probe to concentrate the geomagnetic field into a beam, the resulting electromagnetic beam propagates in a straight line, and when it encounters a material interface, it generates resonant scattering. The resonant scattering causes magnetic anomalies at the scattering boundary, and the positioning detection is achieved by detecting the location of the magnetic anomalies.

3. A method for scanning and detecting using low-frequency electromagnetic resonance, characterized in that, The process includes the following steps: using a horizontal probe to concentrate the Earth's magnetic field into a beam, the resulting electromagnetic beam propagates in a straight line, and resonates and scatters when it encounters interfaces between different materials.

4. The method for scanning detection using low-frequency electromagnetic resonance according to claim 1, 2, or 3, characterized in that, A horizontal probe is used to concentrate the geomagnetic field at the detection point and form a horizontal electromagnetic beam.

5. The method for scanning detection using low-frequency electromagnetic resonance according to claim 1, 2, or 3, characterized in that, When an electromagnetic beam encounters a material interface with different magnetoresistance materials along its propagation path, it will generate low-frequency electromagnetic wave resonant scattering. The different low-frequency electromagnetic wave resonant scattering patterns are conical and cause magnetic anomalies at the scattering boundary. Magnetic anomalies can be detected by cutting magnetic field lines.

6. The method for scanning detection using low-frequency electromagnetic resonance according to claim 5, characterized in that, The method for detecting magnetic anomalies by cutting magnetic field lines is as follows: Using the angle of scattering by a horizontal probe By applying control, the following equation is obtained: Wherein, L is the distance from the horizontal probe to the anomaly point during detection, and H is the depth of the calculated interface.

7. The method for scanning detection using low-frequency electromagnetic resonance according to claim 6, characterized in that, The angle of low-frequency electromagnetic wave resonant scattering using a horizontal probe Perform control and make =1 , or .

8. The method for scanning detection using low-frequency electromagnetic resonance according to claim 5, characterized in that, Different material interfaces have different resonant frequencies.

9. The method for scanning detection using low-frequency electromagnetic resonance according to claim 5, characterized in that, When using a horizontal probe for scanning, the horizontal probe is placed on the surface of the object to be detected, and a scanning point is formed at a spacing of 1cm to 100cm. The interface depth of each scanning point is calculated. The interface detected at each detection point consists of multiple layers. Then, based on the interface depth of each detection point, the structural shape inside the object surface is outlined, and the material type between each interface is determined based on the material frequency signal characteristics of the material.

Images