Ultra-wideband radar echo signal extraction method, system and equipment for detecting external insulation defects of power system, and medium

Abstract

The invention belongs to the technical field of external insulation equipment detection, and discloses an ultra-wideband radar echo signal extraction method, system and equipment for external insulation defect detection of a power system and a medium, so as to solve the problem that a signal processing algorithm in the prior art has obvious insufficiency in the aspect of suppressing fine differences between clutters and amplification signals. The method comprises the following steps: generating relative rotation motion around the symmetry axis of a tested external insulation device between a radar antenna and the tested external insulation device, and transmitting ultra-wideband electromagnetic pulses to the tested external insulation device through a transmitting antenna at intervals of a preset angle in the rotation process, original echo signals in different relative directions are obtained through a receiving antenna; carrying out time domain average processing on all the original echo signals in different relative directions, and calculating to obtain an average signal representing the overall contour reflection of the external insulation equipment; and subtracting the average signal from the original echo signal in each detection direction to obtain a defect echo signal in the corresponding detection direction.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of external insulation equipment detection, and particularly relates to an ultra-wideband radar echo signal extraction method, system, device and medium for external insulation defect detection of a power system. BACKGROUND

[0002] Many studies have shown that in many target detection scenarios using ultra-wideband impulse radar, there is a prominent problem: the radar reflection signal strength of other objects often exceeds that of the target. For example, the studies of Chen Jie (Chen Jie. Ultra-wideband radar signal processing and imaging method research[D]. Graduate School of the Chinese Academy of Sciences (Institute of Electronics), 2007.) and Jin Tian (Jin Tian. Ultra-wideband SAR shallow buried target imaging and detection theory and technology research[D]. University of Defense Science and Technology, 2007.) pointed out that when a ground penetrating radar detects underground pipelines, the ground surface reflection signal strength is large; the studies of Li Xiangping (Li Xiangping, Wang Mingze, Du Bo, et al. Multi-domain joint clutter suppression algorithm based on robust principal component analysis[J]. Journal of Electronics & Information, 2022, 44(04): 1303-1310.) and Zhu Jilun (Zhu Jilun, Qian Hengyuan, Xu Peihang. Wall-penetrating radar clutter suppression algorithm based on left-singular vector entropy analysis[J]. Information Technology and Informationization, 2024, (08): 17-22.) also showed that when a wall-penetrating radar detects target activities behind the wall, the wall reflection signal strength is also relatively significant. These relatively strong non-target reflection signals can seriously interfere with the imaging effect of the target object, leading to a decline in imaging quality and affecting the accurate identification and judgment of the target, which is the primary defect of the prior art in practical application.

[0003] In typical detection scenarios such as ground penetration and wall penetration, ultra-wideband impulse radar transmits time-domain narrow pulse signals, and there is usually a large distance between the target and other objects, so the target reflection signal and the non-target reflection signal are relatively easy to distinguish in the time domain. However, external insulation equipment of a power system has its particularity, with relatively small size and even smaller defect size. This causes the radar reflection signal of the external insulation defect to overlap with the overall profile reflection signal of the external insulation equipment in the time domain, making it difficult to extract the defect signal by simply using a time-domain windowing method. The prior art lacks effective signal extraction means for this special case, and cannot accurately separate the defect signal, thereby limiting the detection capability of the external insulation equipment defect, which is another defect of the prior art in this specific field.

[0004] In addition, due to the size limitation of the external insulation device, the interface of the object reflecting the radar signal presents a three-dimensional curved surface feature at each radar detection angle, which is completely different from the approximately planar case in ground penetration, wall penetration and other scenarios. When the radar detects along a straight line or in an array form, there is a difference in the time delay of the signal reflected by the object, which further increases the difficulty of extracting the defect signal. The prior art fails to fully consider the time delay difference problem caused by the three-dimensional curved surface reflection, lacks effective solutions, and cannot accurately obtain the defect signal in a complex detection environment, affecting the accuracy and reliability of the detection.

[0005] In terms of waveform, the external insulation device usually has an axisymmetric structure, the structure in each direction is basically consistent, and the defect size is relatively small compared to the whole external insulation device. According to the research of Wang Xi et al. (Wang Xi, Li Haichao, Chang Guiqing. Single-channel circular track SAR three-dimensional imaging processing based on joint sparse constraint [J]. Modern Radar, 2022, 44(12): 55-62. DOI:10.16592 / j.cnki.1004-7859.2022.12.008.), the echo waveforms in different directions obtained by using the circular track synthetic aperture radar method are similar in the whole, only with slight differences. In the commonly used signal processing method, although the frequency domain Fourier transform related algorithm can process the overall spectrum of the signal, it is difficult to distinguish the slight differences between different signals. Moreover, in addition to the target echo, there are other echoes such as direct coupling waves of the transmitting and receiving antennas and reflected waves of metal objects in the radar echo. For insulators and other small objects mainly composed of insulating materials and surrounded by metal devices, the target echo is easily submerged in clutter.

[0006] In summary, the signal processing algorithm in the prior art has obvious deficiencies in suppressing clutter and amplifying slight differences between signals, and cannot effectively extract the target echo signal submerged in clutter, which cannot meet the demand for accurate detection of defects in external insulation devices. SUMMARY

[0007] Based on the above-mentioned shortcomings and deficiencies in the prior art, one of the purposes of the present application is to at least solve one or more of the above-mentioned problems in the prior art, in other words, one of the purposes of the present application is to provide an ultra-wideband radar echo signal extraction method, system, device and medium for external insulation defect detection of a power system to meet one or more of the above-mentioned needs, so as to significantly improve the suppression ability of clutter, accurately amplify the slight differences between signals, thereby efficiently and accurately extracting the target echo signal submerged in clutter, and realizing high-precision and high-reliability detection of defects in external insulation devices of a power system.

[0008] In order to achieve the above-mentioned purposes, the present application adopts the following technical solutions.

[0009] In a first aspect, the present application provides a method for extracting ultra-wideband radar echo signals for power system external insulation defect detection, comprising the following steps: S1, generating relative rotational motion between a radar antenna and a measured external insulation device around the symmetry axis of the measured external insulation device, and during the rotation, transmitting an ultra-wideband electromagnetic pulse to the measured external insulation device at a preset angle interval through the transmitting antenna, and obtaining the original echo signal at different relative positions through the receiving antenna; S2, performing time-domain average processing on all original echo signals at different relative positions obtained in step S1 to calculate an average signal representing the overall profile reflection of the external insulation device; S3, subtracting the original echo signal at each detection position in step S1 from the average signal calculated in step S2 to obtain a defect echo signal at the corresponding detection position.

[0010] As a preferred scheme, the relative rotational motion in step S1 is realized by circular track synthetic aperture radar, specifically: the transmitting antenna and the receiving antenna are controlled to rotate around the symmetry axis of the measured external insulation device, and the maximum radiation directions of the transmitting antenna and the receiving antenna are kept aligned with the measured external insulation device.

[0011] As a preferred scheme, an inverse synthetic aperture radar mode is used instead of the circular track synthetic aperture radar, specifically: the measured external insulation device is controlled to rotate around its own symmetry axis, and the maximum radiation directions of the stationary transmitting antenna and the receiving antenna are kept aligned with the measured external insulation device.

[0012] As a preferred scheme, the original echo signal includes a clutter signal generated by the overall profile reflection of the measured external insulation device, a target signal generated by the internal defect reflection of the measured external insulation device, and a noise signal; in step S2, the time-domain average processing is based on: modeling the clutter signal as a fixed signal that does not change with the detection position, and estimating it by calculating the arithmetic mean of all original echo signals.

[0013] In a second aspect, the present application provides an ultra-wideband radar echo signal extraction system for power system external insulation defect detection, which is used to realize the ultra-wideband radar echo signal extraction method as described in the first aspect, comprising an ultra-wideband radar module, a motion control module, and a signal processing module: the ultra-wideband radar module comprises a transmitting antenna and a receiving antenna; the transmitting antenna is used to transmit an ultra-wideband electromagnetic pulse according to preset parameters; the receiving antenna is used to receive the original echo signal reflected from the measured external insulation device and transmit the original echo signal to the signal processing module; the motion control module is used to drive the relative rotational motion between the radar antenna and the measured external insulation device around the symmetry axis of the measured external insulation device; the signal processing module is used to receive the original echo signal and perform time-domain average processing to calculate a defect echo signal.

[0014] As a preferred solution, the motion control module performs a circular synthetic aperture radar operation: controls the transmitting antenna and the receiving antenna to rotate around the symmetry axis of the measured external insulation device, and keeps the maximum radiation direction of the transmitting antenna and the receiving antenna aligned with the measured external insulation device.

[0015] As a preferred solution, the motion control module performs an inverse synthetic aperture radar operation: controls the measured external insulation device to rotate around its own symmetry axis, and keeps the maximum radiation direction of the stationary transmitting antenna and the receiving antenna aligned with the measured external insulation device.

[0016] As a preferred solution, the signal processing module performs time domain averaging processing based on modeling the clutter signal generated by the overall profile reflection of the measured external insulation device as a fixed signal that does not change with the detection azimuth, and estimating it by calculating the arithmetic mean of the original echo signals at all detection azimuths.

[0017] In a third aspect, the present application provides an electronic device, which comprises a memory, a processor and a computer program, and the computer program, when executed by the processor, implements the ultra-wideband radar echo signal extraction method according to the first aspect.

[0018] In a fourth aspect, the present application provides a computer readable storage medium, which stores a computer program, and the computer program, when executed by a processor, implements the ultra-wideband radar echo signal extraction method according to the first aspect.

[0019] Compared with the prior art, the present application has the following beneficial effects: 1. In the defect detection mode, the present application selects the CSAR mode for defect detection. This mode can ensure that there is no relative time delay in the outer profile reflection signal of the measured target at each detection azimuth, thereby greatly facilitating the subsequent signal processing work.

[0020] 2. In the signal processing method, the present application uses the mean suppression method to deeply process the original signal. This method ingeniously regards the outer profile reflection signal as clutter, and removes it from the original signal through specific calculation and operation. This processing method is not only simple and easy to implement, but also can efficiently and accurately obtain the defect signal, greatly improving the accuracy and reliability of defect detection, and providing high-quality data support for subsequent defect analysis and processing.

[0021] Further or more detailed beneficial effects will be described in the specific embodiments in the specific implementation. BRIEF DESCRIPTION OF DRAWINGS

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the 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.

[0023] Figure 1 This is a flowchart illustrating the ultra-wideband radar echo signal extraction method described in Embodiment 1 of the present invention.

[0024] Figure 2 This is a schematic diagram illustrating the principle of acquiring the original echo signal based on CSAR in Embodiment 1 of the present invention.

[0025] Figure 3 This is a schematic diagram illustrating the principle of obtaining the original echo signal based on inverse CSAR in Embodiment 1 of the present invention.

[0026] Figure 4 This is a schematic diagram of the ultra-wideband radar echo signal extraction system described in Embodiment 2 of the present invention.

[0027] Figure 5 This is a structural diagram of the electronic device described in Embodiment 3 of the present invention.

[0028] Figure 6 This is a schematic diagram of the simulation experiment of Embodiment 5 of the present invention.

[0029] Figure 7 This is a schematic diagram of the detection process in the simulation experiment of Embodiment 5 of the present invention.

[0030] Figure 8 This is a schematic diagram of the original reflected signal obtained from the simulation experiment in Embodiment 5 of the present invention.

[0031] Figure 9 This is a schematic diagram of the reflected signal after mean suppression processing in the simulation experiment of Embodiment 5 of the present invention.

[0032] Figure 10 This is an image of the original reflected signal obtained from the simulation experiment in Embodiment 5 of the present invention.

[0033] Figure 11 This is an image of the reflection signal after mean suppression processing in the simulation experiment of Embodiment 5 of the present invention.

[0034] Icon labels: 500. Electronic devices; 501. Processor; 502. Communication bus; 503. User interface; 504. Network interface; 505. Memory. Detailed Implementation

[0035] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0036] In the following description, several embodiments of the present invention are provided. Different embodiments can be substituted or combined. Therefore, the present invention can also be considered to include all possible combinations of the same and / or different embodiments described. Thus, if one embodiment includes features A, B, and C, and another embodiment includes features B and D, then the present invention should also be considered to include embodiments containing one or more other possible combinations of A, B, C, and D, even if such embodiments are not explicitly described in the following text.

[0037] The following description provides examples and does not limit the scope, applicability, or examples set forth in the claims. Changes may be made to the function and arrangement of the described elements without departing from the scope of the invention. Various processes or components may be appropriately omitted, substituted, or added to the various examples. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. Furthermore, features described with respect to some examples may be combined into other examples.

[0038] To facilitate a better understanding of the embodiments of the present invention, its application scenarios will be explained before providing a detailed explanation of the specific implementation methods.

[0039] The ultra-wideband radar echo signal extraction method described in the embodiments of this specification is applied to the defect detection process of external insulation equipment in power systems. In these scenarios, the application of the ultra-wideband radar echo signal extraction method aims to accurately and efficiently separate the defect signal of the external insulation equipment from the complex radar echo signal, providing a reliable basis for subsequent accurate assessment of the health status of the external insulation equipment, timely detection of potential defects, and thus ensuring the safe and stable operation of the power system.

[0040] The following is a brief explanation of the external insulation defect detection, ultra-wideband radar echo signal extraction, time-domain averaging, circular synthetic aperture radar, and inverse synthetic aperture radar involved in several embodiments of this specification: External insulation defect detection is a testing technique for external insulation equipment (such as insulators and bushings) in power systems. Because external insulation equipment is exposed to the natural environment for extended periods, it is affected by various factors such as dirt, moisture, and mechanical stress, which can lead to defects such as decreased insulation performance, surface cracks, and internal air gaps. If these defects are not detected and addressed promptly, they may cause insulation breakdown, short circuits, and other faults, seriously threatening the safe operation of the power system. External insulation defect detection utilizes various technical means, such as electrical measurement, optical inspection, ultrasonic testing, and ultra-wideband radar detection as described in this manual, to discover defects in external insulation equipment and implement appropriate maintenance measures.

[0041] Ultra-wideband radar echo signal extraction: Ultra-wideband radar features an extremely wide transmission bandwidth, providing high-resolution detection capabilities. When detecting externally insulated equipment, the ultra-wideband radar emits electromagnetic pulses towards the equipment and receives the echo signals reflected back. However, these echo signals contain not only reflection information from defects in the external insulation equipment but also reflection signals from the equipment's outer contour and other background clutter. Ultra-wideband radar echo signal extraction involves using a series of signal processing techniques to separate the signal components related only to defects from the complex raw echo signals, enabling accurate analysis and location of defects later. In the embodiments of this specification, methods such as mean suppression are used to treat the outer contour reflection signals as clutter and remove them, thereby achieving effective extraction of defect echo signals.

[0042] Time-domain averaging is a commonly used signal processing method. Its basic principle is to average signals over multiple periods or at multiple moments. In the ultra-wideband radar echo signal extraction method described in this specification, time-domain averaging is used to process the original echo signals of external insulation equipment acquired from different relative orientations. Since the outer contour reflection signal of the external insulation equipment has a certain stability and repeatability in different orientations, while the defect reflection signal is random, by performing time-domain averaging on the original echo signals under all different relative orientations, randomly varying defect signals and other noise interference can be weakened or eliminated, highlighting the stable characteristics of the overall contour reflection signal of the external insulation equipment. This allows for the calculation of an average signal representing the overall contour reflection of the external insulation equipment, providing a reference for subsequent defect signal extraction.

[0043] Circular-track synthetic aperture radar (CSAR) is a special type of synthetic aperture radar operating mode. In this mode, the radar antenna and the target undergo relative rotation around the target's axis of symmetry. During this rotation, the radar emits ultra-wideband electromagnetic pulses at preset intervals and angles towards the target, and receives echo signals from different relative azimuths. CSAR has a unique advantage: it ensures that there is no relative time delay between the reflected signals of the target's outer contour at various detection azimuths. This makes subsequent signal processing simpler and more efficient, as it eliminates the need to consider complex operations such as signal alignment and correction due to time delays. This helps improve the accuracy and efficiency of signal processing, thereby obtaining more accurate information about the target, and is particularly suitable for detecting relatively regular-shaped targets such as externally insulated equipment.

[0044] Inverse synthetic aperture radar (CSAR) operates on the opposite principle to synthetic aperture radar (SAR). In SAR, the radar platform moves, and echo signals from different locations are processed to synthesize a larger equivalent antenna aperture, thereby improving radar resolution. In contrast, inverse synthetic aperture radar operates with the target moving while the radar remains relatively stationary. It processes the echo signals from the target at different times to achieve imaging and identification of the moving target. In the context of this specification, inverse CSAR can be viewed as a method of processing and analyzing CSAR detection data in reverse. Starting from the echo signal data acquired by CSAR, it uses specific algorithms and models to conduct a deeper analysis and exploration of the motion characteristics, internal structure, and defect features of the tested external insulation equipment. This allows it to discover information that might be overlooked in conventional CSAR processing, further enriching and improving the understanding and detection methods for defects in external insulation equipment.

[0045] Example 1: like Figure 1 As shown in the figure, this embodiment provides a method for extracting ultra-wideband radar echo signals for detecting external insulation defects in power systems. The specific steps are as follows: Step S1 involves generating a relative rotational motion between the radar antenna and the external insulation device under test around the axis of symmetry of the external insulation device under test. During the rotation, ultra-wideband electromagnetic pulses are transmitted to the external insulation device under test through the transmitting antenna at preset angle intervals, and the original echo signals at different relative orientations are obtained through the receiving antenna.

[0046] Step S2 involves performing time-domain averaging on the original echo signals obtained in step S1 under all different relative orientations to calculate the average signal representing the overall contour reflection of the external insulation device. It is understood that... Step S3 involves subtracting the original echo signal obtained in step S1 at each detection azimuth from the average signal calculated in step S2 to obtain the defect echo signal at the corresponding detection azimuth.

[0047] Specifically, the raw echo signal can be acquired using CSAR. The transmitting and receiving antennas rotate around the axis of symmetry of the object under test with a certain radius, while maintaining their maximum radiation direction aligned with the object. The transmitting antenna emits ultra-wideband electromagnetic pulse signals towards the object at intervals of a certain rotation angle, and the receiving antenna receives the reflected signal from the object and stores the data. Figure 2 As shown. Continuously rotate at least one revolution to obtain reflected signals from different detection azimuths. If the rotation angle interval is large, multiple revolutions can be performed. Due to relative motion, the detection signal is the same whether the radar antenna rotates relative to the stationary object being measured or the object itself rotates while the radar is stationary. Therefore, the latter can also be used to obtain the reflected signal, known as the "inverse synthetic aperture radar method." In this method, the object being measured rotates around its axis of symmetry with a certain radius, keeping the maximum radiation direction of the stationary transmitting and receiving antenna aligned with the object. After the object rotates a certain angle, the transmitting antenna emits an ultra-wideband electromagnetic pulse signal, and the receiving antenna receives the reflected signal from the object and saves the data, such as... Figure 3 As shown.

[0048] Understandably, because the defects are very small relative to the overall external insulation equipment, the echo waveforms obtained using the CSAR method in different directions only differ slightly. Since the regular insulation structures such as the outer skirts of the insulator are located at similar positions and have similar amplitudes on the received waveforms from various detection directions, the mean suppression method can treat the echo signals generated by these regular insulation structures as clutter and filter them out, highlighting the echo signals of internal defects, thereby amplifying the subtle differences between signals.

[0049] The received signal of an ultra-wideband pulse radar can be expressed as: (1) In equation (1), This indicates the received signal (also known as the original echo signal). This indicates the target reflected signal (also known as the target signal, which is generated by the reflection of internal defects in the external insulation equipment being tested). This indicates clutter signals (generated by reflections from the overall outline of the externally insulated equipment under test). This represents additive noise (also known as noise signal). k Indicates the first k Received waveform data at each detection azimuth. n Indicates the first n One sampling point, L Indicates the number of radar detection azimuths.

[0050] Since the environment surrounding the external insulation equipment generally does not change much, this embodiment assumes that the noise is a fixed signal, that is: (2) Since the clutter signal is unknown, this embodiment estimates the clutter signal from the received data based on the minimum mean square error: (3) In equation (3), 2 This represents the mean square error.

[0051] The clutter signal estimated by equation (3) is: (4) If the target reflected signal is small and the noise is assumed to be zero-mean noise: (5) The clutter estimate is: (6) From equations (2)-(6), it can be seen that clutter can be represented by the average value of all detection directions, and the target echo signal can be expressed as: (7) When detecting internal defects in external insulation equipment, the above formula shows that the tiny signal caused by the internal defects... The impact on clutter estimation error is small; for external clutter interference, which is mainly reflected by isolated targets such as metal objects and occupies a relatively small space, the deviation in clutter estimation is small. Therefore, the mean value method can be used to suppress the influence of external insulation structure on waveform, thereby improving the imaging capability of internal defects.

[0052] Example 2: like Figure 4 As shown, this embodiment provides an ultra-wideband radar echo signal extraction system for detecting external insulation defects in power systems. It implements the ultra-wideband radar echo signal extraction method described in Embodiment 1, and includes an ultra-wideband radar module, a motion control module, and a signal processing module. The ultra-wideband radar module includes a transmitting antenna and a receiving antenna. The transmitting antenna transmits ultra-wideband electromagnetic pulses according to preset parameters, and the receiving antenna receives the raw echo signal reflected from the external insulation device under test and transmits the raw echo signal to the signal processing module. The motion control module drives the relative rotational movement between the radar antenna and the external insulation device under test around the axis of symmetry of the external insulation device. The signal processing module receives the raw echo signal and performs time-domain averaging to calculate the defect echo signal.

[0053] Specifically, the motion control module performs circular trace synthetic aperture radar operation: controlling the transmitting antenna and the receiving antenna to rotate around the axis of symmetry of the external insulation device under test, and keeping the maximum radiation direction of the transmitting antenna and the receiving antenna aligned with the external insulation device under test.

[0054] Specifically, the motion control module performs inverse synthetic aperture radar operation: controlling the tested external insulation device to rotate around its own axis of symmetry, and keeping the maximum radiation direction of the stationary transmitting antenna and receiving antenna aligned with the tested external insulation device.

[0055] Specifically, the signal processing module performs time-domain averaging based on the following: the clutter signal generated by the reflection of the overall outline of the external insulation device under test is modeled as a fixed signal that does not change with the detection orientation, and the signal is estimated by calculating the arithmetic mean of the original echo signals under all detection orientations.

[0056] Example 3: like Figure 5 As shown, this embodiment provides an electronic device, which may include: at least one processor, at least one network interface, a user interface, a memory, and at least one communication bus.

[0057] The communication bus can be used to enable communication between the various components mentioned above.

[0058] The user interface may include buttons, and optional user interfaces may also include standard wired interfaces and wireless interfaces.

[0059] The network interface may include, but is not limited to, Bluetooth modules, NFC modules, Wi-Fi modules, etc.

[0060] The processor may include one or more processing cores. It connects various parts of the electronic device via various interfaces and lines, executing instructions, programs, code sets, or instruction sets stored in memory, and accessing data stored in memory to perform various functions and process data. Optionally, the processor can be implemented using at least one hardware form of DSP, FPGA, or PLA. The processor may integrate one or more of the following: CPU, GPU, and modem. The CPU primarily handles the operating system, user interface, and applications; the GPU is responsible for rendering and drawing the content required for display; and the modem handles wireless communication. It is understood that the modem may also be implemented as a separate chip without being integrated into the processor.

[0061] The memory may include RAM or ROM. Optionally, the memory may include a non-transitory computer-readable medium. The memory can be used to store instructions, programs, code, code sets, or instruction sets. The memory may include a program storage area and a data storage area, wherein the program storage area may store instructions for implementing an operating system, instructions for at least one function (such as touch function, sound playback function, image playback function, etc.), instructions for implementing the above-described method embodiments, etc.; the data storage area may store data involved in the above-described method embodiments, etc. Optionally, the memory may also be at least one storage device located remotely from the aforementioned processor. The memory, as a computer storage medium, may include an operating system, a network communication module, a user interface module, and an extraction application program. The processor can be used to call the extraction application program stored in the memory and execute the steps of the ultra-wideband radar echo signal extraction method mentioned in the foregoing embodiments.

[0062] Example 4: This embodiment provides a computer-readable storage medium storing instructions that, when executed on a computer or processor, cause the computer or processor to perform the above-described instructions. Figure 1 One or more steps in the illustrated embodiment. If the constituent modules of the above-described electronic device are implemented as software functional units and sold or used as independent products, they can be stored in the computer-readable storage medium.

[0063] In the above embodiments, implementation can be achieved, in whole or in part, through software, hardware, firmware, or any combination thereof. When implemented in software, it can be implemented, in whole or in part, as a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this specification are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in or transmitted through a computer-readable storage medium. The computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, Digital Subscriber Line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium accessible to a computer or a data storage device such as a server or data center that integrates one or more available media. The available media may be magnetic media (e.g., floppy disks, hard disks, magnetic tapes), optical media (e.g., Digital Versatile Discs (DVDs)), or semiconductor media (e.g., Solid State Disks (SSDs)).

[0064] Those skilled in the art will understand that all or part of the processes in the method of Embodiment 1 described above can be implemented by a computer program instructing related hardware. This program can be stored in a computer-readable storage medium, and when executed, it can include the processes of the embodiments of the methods described above. The aforementioned storage medium includes various media capable of storing program code, such as ROM, RAM, magnetic disks, or optical disks. Unless otherwise specified, the technical features of this embodiment and the implementation scheme can be combined arbitrarily.

[0065] Example 5: To verify the effectiveness of the ultra-wideband radar echo signal extraction method for detecting external insulation defects in power systems described in this specification, this embodiment uses CST software (CST Studio Suite) for simulation experiments.

[0066] See Figure 6 In the simulation experiment, the object under test was a ceramic cylinder with a diameter of 160 mm, containing an internal defect: a circular cavity with a radius of 5 mm, located 48 mm from the axis. Both the transmitting and receiving antennas were ultra-wideband antennas, with the same usable bandwidth as the pulse source, ranging from 0.3 to 3 GHz.

[0067] During the detection process, the transmitting and receiving antennas rotate together around the axis of the object being measured. Throughout this motion, the radius of their motion and the distance between them remain constant, and their maximum radiation direction is always aligned with the center of the object being measured. (See also...) Figure 7 During the rotation of the transmitting antenna, electromagnetic pulses are emitted at equal intervals toward the object being measured, while the receiving probe is responsible for acquiring the reflected signals.

[0068] In this simulation, the transmitting antenna and receiving probe synchronously rotated around the object under test by a certain angle, acquiring a total of 18 sets of data. In each set of data, 6561 data points were recorded for each time-domain waveform, with a time window set to 15 ns. The original electric field signals received from different detection orientations are shown below. Figure 8 As shown. After processing the original electric field signals from different detection azimuths using the averaging method, the waveforms are as follows. Figure 9 As shown, the differences between the waveforms are significantly amplified, thereby obtaining the reflection information of the internal structure.

[0069] Subsequently, the object under test is imaged using the BP algorithm. The imaging results using the original reflected signal are as follows: Figure 10 As shown, the imaging result of the signal after processing with the mean suppression method is as follows: Figure 11 As shown in the figure. A comparison reveals that the original reflected signal imaging results only show the outer contour, with significant energy enhancement only at the internal axis, making it impossible to image the defect. However, the defect signal imaging results processed using the mean suppression method allow for a rough determination that the defect shape is circular, and the defect location is determined to be 44.7 mm from the axis, a deviation of 6.9% from the actual value, with no deviation in angular position.

[0070] Therefore, the ultra-wideband radar echo signal extraction method used in this embodiment can effectively extract defect signals, which is helpful for defect imaging. Based on the above experimental process and results, this embodiment verifies the effectiveness of the ultra-wideband radar echo signal extraction method for detecting external insulation defects in power systems described in this specification.

[0071] It should be noted that, for the sake of simplicity, the foregoing method embodiments are all described as a series of actions. However, those skilled in the art should understand that the present invention is not limited to the described order of actions, because according to the present invention, some steps can be performed in other orders or simultaneously. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions and modules involved are not necessarily essential to the present invention.

[0072] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0073] The above description is merely an exemplary embodiment of the present invention and should not be construed as limiting the scope of the invention. Any equivalent changes and modifications made in accordance with the teachings of this invention are still within the scope of this invention. Those skilled in the art will readily conceive of embodiments of the invention upon considering the specification and practicing the disclosure herein. This invention is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not described herein. The specification and embodiments are to be considered exemplary only, and the scope and spirit of the invention are defined by the claims.

Claims

1. A method for extracting ultra-wideband radar echo signals for detecting external insulation defects in power systems, characterized in that, Including the following steps: S1. A relative rotational motion is generated between the radar antenna and the external insulation device under test around the axis of symmetry of the external insulation device under test. During the rotation, ultra-wideband electromagnetic pulses are emitted to the external insulation device under test through the transmitting antenna at preset angle intervals, and the original echo signals under different relative orientations are obtained through the receiving antenna. S2. Perform time-domain averaging on all the original echo signals obtained in step S1 under different relative orientations to calculate the average signal representing the overall contour reflection of the external insulation device. S3. Subtract the original echo signal obtained in step S1 at each detection azimuth from the average signal obtained in step S2 to obtain the defect echo signal at the corresponding detection azimuth.

2. The method for extracting ultra-wideband radar echo signals for detecting external insulation defects in power systems according to claim 1, characterized in that, The relative rotational motion in step S1 is achieved through circular trajectory synthetic aperture radar, specifically as follows: Control the transmitting antenna and the receiving antenna to rotate around the axis of symmetry of the external insulation device under test, and keep the maximum radiation direction of the transmitting antenna and the receiving antenna aligned with the external insulation device under test.

3. The method for extracting ultra-wideband radar echo signals for detecting external insulation defects in power systems according to claim 2, characterized in that, The circular-track synthetic aperture radar is replaced by an inverse synthetic aperture radar method, specifically: The maximum radiation direction of the transmitting antenna and the receiving antenna, which are kept stationary, is aligned with the external insulation device under test, while the device rotates around its own axis of symmetry.

4. The method for extracting ultra-wideband radar echo signals for detecting external insulation defects in power systems according to claim 3, characterized in that: The original echo signal includes clutter signals generated by reflections of the overall outline of the external insulation equipment under test, target signals generated by reflections of internal defects in the external insulation equipment under test, and noise signals; In step S2, the basis for the time-domain averaging process is: The clutter signal is modeled as a fixed signal that does not change with the detection azimuth and is estimated by calculating the arithmetic mean of all the original echo signals.

5. An ultra-wideband radar echo signal extraction system for detecting external insulation defects in power systems, characterized in that, To implement the ultra-wideband radar echo signal extraction method as described in claim 4, the method includes an ultra-wideband radar module, a motion control module, and a signal processing module: The ultra-wideband radar module includes a transmitting antenna and a receiving antenna; The transmitting antenna is used to transmit ultra-wideband electromagnetic pulses according to preset parameters; The receiving antenna is used to receive the original echo signal reflected back from the external insulation device under test, and to transmit the original echo signal to the signal processing module; The motion control module is used to drive the relative rotational motion between the radar antenna and the external insulation device under test around the axis of symmetry of the external insulation device under test. The signal processing module is used to receive the original echo signal and perform time-domain averaging to calculate the defect echo signal.

6. The ultra-wideband radar echo signal extraction system for detecting external insulation defects in power systems according to claim 5, characterized in that, The motion control module performs circular trajectory synthetic aperture radar operations: Control the transmitting antenna and the receiving antenna to rotate around the axis of symmetry of the external insulation device under test, and keep the maximum radiation direction of the transmitting antenna and the receiving antenna aligned with the external insulation device under test.

7. The ultra-wideband radar echo signal extraction system for detecting external insulation defects in power systems according to claim 5, characterized in that, The motion control module performs inverse synthetic aperture radar operations: The maximum radiation direction of the transmitting antenna and the receiving antenna, which are kept stationary, is aligned with the external insulation device under test, while the device rotates around its own axis of symmetry.

8. The ultra-wideband radar echo signal extraction system for detecting external insulation defects in power systems according to claim 5, characterized in that, The basis for the time-domain averaging process performed by the signal processing module is: The clutter signal generated by the reflection of the overall outline of the external insulation equipment under test is modeled as a fixed signal that does not change with the detection azimuth, and is estimated by calculating the arithmetic mean of the original echo signals under all detection azimuths.

9. A computer device, the computer device comprising a memory, a processor, and a computer program, characterized in that, When the computer program is executed by the processor, it implements the ultra-wideband radar echo signal extraction method as described in any one of claims 1 to 4.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the ultra-wideband radar echo signal extraction method as described in any one of claims 1 to 4.

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