A cable defect detection method combining electromagnetic induction and dynamic signal analysis

Abstract

The application provides a cable defect detection method combining electromagnetic induction and dynamic signal analysis, comprising the following steps: acquiring the running speed of the inspection device in real time through an encoder, dynamically switching the excitation signal frequency, and adapting to the detection requirements of different depth defects; S2, applying pulse excitation to the detection mechanism with a three-coil axisymmetric layout, exciting cable eddy current, and receiving defect voltage signals through a differential coil; S3, analyzing the fluctuation mode of the differential signal, combining the amplitude change and the recovery time to locate the defect and calculate the geometric characteristics; S4, according to the correlation of speed and time, storing the defect coordinates to the microprocessor; S5, based on the simulation optimization model, quantitatively evaluating the number of broken strands, defect depth and severity grade. The device realizes 360° non-blind area detection of the cable and high-precision evaluation of the broken strand depth through the three-coil axisymmetric electromagnetic induction detection technology, combined with the speed-adaptive dynamic excitation frequency adjustment and the differential signal recognition of the defect position.

Description

Technical Field

[0001] This invention relates to the field of cable testing technology, and more particularly to a cable defect detection method that combines electromagnetic induction and dynamic signal analysis. Background Technology

[0002] With the rapid increase in the mileage of overhead cables in my country, traditional manual inspection methods can no longer meet the demands of high-intensity and high-precision line inspection. Currently, mainstream non-destructive testing technologies (such as infrared thermal imaging, ultrasonic testing, and lidar) generally suffer from low detection efficiency, poor environmental adaptability, and insufficient ability to identify deep defects. Although electromagnetic detection technology has been partially applied abroad, related research in China started relatively late. Existing technologies still rely on complex mechanical structures to achieve detection functions. While existing electromagnetic detection robots can partially replace manual labor, their core defect detection technology still faces significant bottlenecks. Traditional single / dual coil sensors, due to their asymmetrical layout, generate a circumferential blind zone of ≥120°, making it impossible to identify deep defects such as broken strands and internal cracks in cables. Furthermore, existing electromagnetic detection devices use fixed excitation frequencies, resulting in insufficient resolution of deep defects at low speeds and signal aliasing at high speeds due to insufficient sampling rates, making it difficult to capture rapidly moving defects. In addition, the unreasonable design of existing coil spacing leads to severe coupling interference, and the selection of conductor diameter does not balance parasitic resistance and noise sensitivity, resulting in a signal-to-noise ratio generally below 15dB. Of particular concern is the lack of precision in quantifying defects in existing methods: single sensor signals lack complementary verification mechanisms, cannot suppress environmental noise through multi-source data fusion, and defect judgment relies on empirical thresholds. Furthermore, no quantitative evaluation model based on electromagnetic field simulation has been established, resulting in a misjudgment rate of over 20% for key parameters such as the number of broken strands and crack depth.

[0003] Therefore, there is an urgent need to develop a cable defect detection method that can achieve 360° blind-zone-free circumferential detection of cables, simultaneously improve the sensitivity of deep defects and the ability to capture dynamic defects, and construct an anti-interference, high-precision defect quantification model. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a cable defect detection method that combines electromagnetic induction and dynamic signal analysis. The device utilizes electromagnetic induction detection technology with a three-coil axisymmetric layout, combined with speed-adaptive dynamic excitation frequency adjustment and differential signal identification of defect locations, to achieve 360° blind-zone-free circumferential cable detection and high-precision assessment of strand breakage depth.

[0005] To achieve the above objectives, the present invention provides a cable defect detection method combining electromagnetic induction and dynamic signal analysis, comprising the following steps;

[0006] S1. The walking speed of the inspection device is obtained in real time through the encoder, and the frequency of the electromagnetic excitation signal is dynamically adjusted. At low speed, a low-frequency signal is used to extend the sampling time and enhance the deep defect detection capability. At high speed, a high-frequency signal is switched to improve the sampling rate and capture information on rapidly moving defects.

[0007] S2. Apply a pulse excitation signal to the detection coil with a three-coil axisymmetric layout to excite eddy currents on the surface and inside the cable, and receive the voltage signal caused by the defect through the differential coil;

[0008] S3. Analyze the fluctuation pattern of the differential signal and identify defect features: When the differential signal exhibits a continuous fluctuation of "increase-decrease-increase", it is determined to be the location of the defect, and the geometric features of the defect are calculated based on the signal amplitude change and the response time.

[0009] S4. Combining speed information and defect location data, the microprocessor records and stores the defect coordinates and signal parameters.

[0010] S5. Based on the preset simulation optimization model, quantitative analysis is performed on the amplitude, phase and waveform characteristics of the differential signal to assess the severity of the defect, including the number of broken strands and the depth of the defect.

[0011] Furthermore, in the three-coil axisymmetric layout, the three detection coils are symmetrically distributed at 120° equiangular angles with the cable as the axis, and the spacing between adjacent coils is 1 / 4 of the excitation signal wavelength, which is used to eliminate detection blind spots and realize 360° full circumferential electric field complementary detection.

[0012] Furthermore, in step S2, a detection coil is wound with a wire of 1 mm in diameter to balance parasitic resistance and noise immunity, and external interference is suppressed by multi-coil signal fusion.

[0013] The present invention also provides an electromagnetic composite detection device, comprising: a three-coil detection mechanism, a control center, and a drive mechanism; wherein,

[0014] The three-coil detection mechanism is arranged in an axisymmetric isoangular layout, including independently detachable detection coils and a hollowed-out housing model;

[0015] The control center includes a signal receiver, a brushless motor driver board, and a microprocessor, which are used to dynamically adjust the excitation frequency and perform signal analysis.

[0016] The drive mechanism includes a silicone wheel driven by a brushless motor and a driven wheel. The radius of the groove opening of the driven wheel is larger than the diameter of the cable, and a retaining edge is provided on the outside to constrain the direction of travel.

[0017] Furthermore, the driven wheel and the silicone wheel are assembled into a coaxial structure through the wheel drive housing, and the wheel drive housing is connected to symmetrically distributed electric push rods through a damping hinge to realize the synchronous extension and retraction and angle adaptive adjustment of the pressing mechanism.

[0018] Furthermore, the electric push rod controls its extension length via a remote control signal, causing the drive mechanism to press cables of different sizes together.

[0019] Furthermore, the control center includes a signal conversion chip, which converts the forward and reverse signals output by the remote control into speed control commands for the brushless motor, and synchronizes defect location data and speed information in real time.

[0020] Furthermore, the hollowed-out housing model is compatible with ultrasonic sensors and supports the expansion installation of multimodal detection modules.

[0021] Furthermore, the detection mechanism and the drive mechanism are symmetrically distributed around the cable, and three symmetrical containment models are configured at the tail to balance the mass distribution of the device and reduce the overturning moment.

[0022] By adopting the above technical solution, the present invention has the following advantages compared with the prior art:

[0023] 1. The present invention provides a cable defect detection method that combines electromagnetic induction and dynamic signal analysis. By using a three-coil axisymmetric layout, with 120° equiangular distribution and a spacing of 1 / 4 of the excitation signal wavelength, a complementary spatial electric field is formed, eliminating the circumferential blind zone of traditional single / double coil detection systems, realizing 360° full coverage detection of cables, reducing the defect identification blind zone to 0°, and significantly improving the detection rate of deep defects such as broken strands and cracks.

[0024] 2. The present invention provides a cable defect detection method that combines electromagnetic induction and dynamic signal analysis. Based on the real-time speed feedback of the motor encoder, the excitation frequency is dynamically switched to simultaneously improve the penetration capability of deep defects and the efficiency of rapid defect capture. Combined with the simulation optimization model, the amplitude, phase and waveform characteristics of the differential signal are quantitatively analyzed to reduce the evaluation error rate of the number of broken strands and the depth of defects.

[0025] 3. The present invention provides a cable defect detection method that combines electromagnetic induction and dynamic signal analysis. It adopts a hollowed-out housing model to support the independent disassembly and rapid replacement of the detection coil, avoiding equipment downtime due to a single fault. It is compatible with the symmetrical installation design of multi-modal sensors such as ultrasonic sensors, which expands the detection function and adapts to the diverse detection needs under complex working conditions.

[0026] Based on the above reasons, this invention can be widely promoted in the field of cable testing technology. Attached Figure Description

[0027] 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 some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a flowchart of a cable defect detection method combining electromagnetic induction and dynamic signal analysis as described in this invention;

[0029] Figure 2 This is a diagram showing the arrangement of three coils in a cable defect detection method combining electromagnetic induction and dynamic signal analysis as described in this invention.

[0030] Figure 3 This is a schematic diagram of the combined closed loop of the three-coil detection device and the driving device in the cable defect detection method combining electromagnetic induction and dynamic signal analysis described in this invention.

[0031] Figure 4 This is a schematic diagram showing the combination of a three-coil detection device and a driving device in a cable defect detection method that combines electromagnetic induction and dynamic signal analysis, as described in this invention.

[0032] In the diagram: 1. Detection coil housing; 2. Three-coil detection mechanism; 3. Integrated frame; 4. Electric push rod; 5. Wheel drive housing; 6. Driven wheel; 7. Driven wheel axle; 8. Damping hinge. Detailed Implementation

[0033] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0034] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0036] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following drawings denote similar items; therefore, once an item is defined in one drawing, it need not be further discussed in subsequent drawings.

[0037] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this invention. The directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0038] For ease of description, spatial relative terms such as "above," "over," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation besides the orientation of the device as described in the figures. For example, if the device in the figures is inverted, a device described as "above" or "above" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0039] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0040] Example 1

[0041] like Figures 1 to 3 As shown, the present invention provides a cable defect detection method combining electromagnetic induction and dynamic signal analysis, comprising the following steps;

[0042] S1. The walking speed of the inspection device is obtained in real time through the encoder, and the frequency of the electromagnetic excitation signal is dynamically adjusted. At low speed, a low-frequency signal is used to extend the sampling time and enhance the deep defect detection capability. At high speed, a high-frequency signal is switched to improve the sampling rate and capture information on rapidly moving defects.

[0043] S2. Apply a pulse excitation signal to the detection coil with a three-coil axisymmetric layout to excite eddy currents on the surface and inside the cable, and receive the voltage signal caused by the defect through the differential coil;

[0044] S3. Analyze the fluctuation pattern of the differential signal and identify defect features: When the differential signal exhibits a continuous fluctuation of "increase-decrease-increase", it is determined to be the location of the defect, and the geometric features of the defect are calculated based on the signal amplitude change and the response time.

[0045] S4. Combining speed information and defect location data, the microprocessor records and stores the defect coordinates and signal parameters.

[0046] S5. Based on the preset simulation optimization model, quantitative analysis is performed on the amplitude, phase and waveform characteristics of the differential signal to assess the severity of the defect, including the number of broken strands and the depth of the defect.

[0047] Specifically, S1 dynamically adjusts the frequency of the electromagnetic excitation signal, activates the inspection device, and uses an encoder to collect the device's travel speed along the cable in real time, dynamically switching the excitation frequency according to the speed: where,

[0048] Low-speed mode: Use a low-frequency excitation signal (e.g., 1kHz) and extend the sampling time to 10ms to enhance the detection capability of deep defects in cables;

[0049] High-speed mode: Switch to high-frequency excitation signal (e.g., 10kHz), shorten the sampling time to 2ms, and increase the sampling rate to capture fast-moving shallow defects;

[0050] The speed range of the low-speed state is 0 to 1 m / s, and the speed of the high-speed state is >1 m / s.

[0051] The frequency switching logic is controlled in real time by a microprocessor to ensure that the excitation signal matches the travel speed.

[0052] Specifically, S2 applies pulse excitation and receives differential signals, applies pulse excitation signals to the three-coil detection mechanism, and excites eddy currents to be generated on and inside the cable surface. The amplitude of the pulse excitation signal is 5V and the pulse width is 100ns.

[0053] The voltage signal caused by the defect is received through a differential coil: where,

[0054] The three coils capture electromagnetic field changes in different directions, and due to the axisymmetric layout, the signals of each coil complement each other and cover the entire circumference of the cable.

[0055] It adopts a coil design with a wire diameter of 1 mm to balance parasitic resistance and noise immunity, and eliminates external interference through multi-coil signal fusion.

[0056] The raw voltage signal is recorded in real time and transmitted to the microprocessor for preprocessing.

[0057] Specifically, S3 analyzes the fluctuation patterns of differential signals, performs time-domain analysis on the preprocessed differential signals, and identifies characteristic waveforms;

[0058] When the signal exhibits a continuous fluctuation of "increase-decrease-increase", it is determined to be the location of a defect.

[0059] The amplitude change ΔV and the recovery time T are calculated using geometric features, where...

[0060] The amplitude change ΔV is the difference between the calculated peak and valley values, reflecting the defect size. Setting ΔV = 0.25V indicates a defect with a depth ≥ 1mm. The amplitude change ΔV increases exponentially with the depth.

[0061] The recovery time is the time it takes for the peak value to decay back to the baseline. It is related to the defect shape; for example, T < 5 ms indicates a sharp crack, and T > 10 ms indicates a gradually changing indentation.

[0062] By combining the data from the three coils for cross-validation, false detections are eliminated. For example, if a single coil is interfered with, the data from the other two coils are still valid.

[0063] Specifically, S4 records the defect location and parameters, obtains the absolute position of the current inspection device through the encoder, sets the distance from the starting point to X meters, and calculates the defect coordinates by combining the travel speed v and the detection time t.

[0064] Defect location: X = v × t;

[0065] The defect coordinates, ΔV, T, and the original signal waveform are stored in the microprocessor.

[0066] Specifically, S5 quantitatively assesses the severity of defects by calling a pre-set simulation optimization model and inputting ΔV, T, and waveform characteristic parameters based on finite element simulation and experimental calibration data.

[0067] Number of broken strands: Based on the relationship model between ΔV and cable cross-sectional area loss rate, the number of broken strands is determined. It is set that ΔV = 0.2 corresponds to 1 broken strand.

[0068] Defect depth: The depth is determined by the relationship curve between T and decay rate. T = 1 ms corresponds to a depth of 0.5 mm.

[0069] Output the evaluation results and label the levels, where:

[0070] Severity level: ΔV≥0.8V or defect depth≥3mm or number of broken strands≥5 or recovery timeT<4ms. High amplitude / depth defects or sharp cracks with fast response may lead to cable structure breakage or short circuit risk, and immediate shutdown and maintenance are required.

[0071] Medium level: 0.5ΔV≤ΔV<0.8V or 1.5mm≤defect depth<3mm or 2≤number of broken strands<5 or 4ms≤T<8ms, moderate damage, which may affect long-term operational stability and requires planned maintenance and continuous monitoring;

[0072] Minor level: ΔV<0.5V or defect depth<1.5mm or number of broken strands<2 or T≥8ms, shallow or gradually changing defects, which do not pose a significant threat to current operation and can be recorded and periodically re-inspected.

[0073] The test results are transmitted to the ground terminal in real time via a wireless module for verification by maintenance personnel.

[0074] Example 2

[0075] The present invention also provides an electromagnetic composite detection device, comprising: a three-coil detection mechanism 2, a control center, and a drive mechanism; wherein,

[0076] The three-coil detection mechanism 2 is set inside the detection coil housing 1 and is arranged in an axisymmetric equiangular layout, including a detection coil that can be detached independently and a hollowed-out housing model;

[0077] The control center, including a signal receiver, a brushless motor driver board, and a microprocessor, is used to dynamically adjust the excitation frequency and perform signal analysis.

[0078] The driving mechanism includes a silicone wheel driven by a brushless motor and a driven wheel 6. The radius of the groove opening of the driven wheel 6 is larger than the diameter of the cable, and a retaining edge is provided on the outside to constrain the direction of travel.

[0079] The simplified design of the silicone wheel being directly connected to the output shaft of the brushless motor via a flange reduces transmission loss and improves drive efficiency. At the same time, the guide of the driven wheel with 6 grooves and the constraint of the guard edge ensure that the inspection device moves accurately along the cable direction. The control center integrates remote speed regulation and clamping force feedback functions to realize remote operation and adaptive clamping, reducing the difficulty of manual intervention.

[0080] The radius of the groove opening in the middle of the driven wheel 6 is larger than the diameter of the cable, and a retaining edge is provided on the outside. It is fixed to the wheel drive housing 5 by the driven wheel shaft 7 and the bearing. The driven wheel 6 and the silicone wheel are assembled into a coaxial structure through the wheel drive housing 5.

[0081] The electric push rods 4 are symmetrically fixed between the integrated outer frame 3 and the wheel drive housing 5 via damping hinges 8, realizing synchronous extension and retraction of the clamping mechanism and adaptive angle adjustment; the electric push rods 4 control the extension and retraction length via remote control signal, so that the drive mechanism clamps cables of different sizes, and the symmetrically distributed electric push rods 4 extend and retract synchronously to adapt to different cable sizes.

[0082] Furthermore, the control center also includes a signal conversion chip, which converts the forward and reverse signals output by the remote control into speed control commands for the brushless motor, and synchronizes defect location data and speed information in real time.

[0083] Furthermore, the hollowed-out containment model is compatible with ultrasonic sensors and supports the expansion installation of multimodal detection modules. Ultrasonic sensors can be installed in the hollowed-out containment model and connected to the control center through a unified interface to achieve electromagnetic-ultrasonic composite detection. At the same time, it supports independent disassembly and replacement of coils, reducing the time required for each coil maintenance.

[0084] Furthermore, the detection mechanism and the drive mechanism are symmetrically distributed around the cable, and three symmetrically arranged containment models are configured at the tail to balance the mass distribution of the device and reduce the overturning moment, effectively balancing the overall mass distribution of the device and eliminating the additional overturning moment caused by the asymmetrical structure.

[0085] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A cable defect detection method combining electromagnetic induction and dynamic signal analysis, characterized in that, Includes the following steps; S1. The walking speed of the inspection device is obtained in real time through the encoder, and the frequency of the electromagnetic excitation signal is dynamically adjusted. At low speed, a low-frequency signal is used to extend the sampling time and enhance the deep defect detection capability. At high speed, a high-frequency signal is switched to improve the sampling rate and capture information on rapidly moving defects. S2. Apply a pulse excitation signal to the detection coils arranged in a three-coil axisymmetric layout to excite eddy currents on and inside the cable surface, and receive the voltage signal caused by the defect through a differential coil; in the three-coil axisymmetric layout, the three detection coils are symmetrically distributed at 120° angles with the cable as the axis, and the distance between adjacent coils is 1 / 4 of the wavelength of the excitation signal, which is used to eliminate the detection blind zone and realize 360° full circumferential electric field complementary detection; S3. Analyze the fluctuation pattern of the differential signal and identify defect features: When the differential signal exhibits a continuous fluctuation of "increase-decrease-increase", it is determined to be the location of the defect, and the geometric features of the defect are calculated based on the signal amplitude change and the response time. S4. Combining speed information and defect location data, the microprocessor records and stores the defect coordinates and signal parameters. S5. Based on the preset simulation optimization model, quantitative analysis is performed on the amplitude, phase and waveform characteristics of the differential signal to assess the severity of the defect, including the number of broken strands and the depth of the defect.

2. The cable defect detection method combining electromagnetic induction and dynamic signal analysis according to claim 1, characterized in that, In step S2, a detection coil is wound with a wire of 1 mm in diameter to balance parasitic resistance and noise immunity, and external interference is suppressed by multi-coil signal fusion.

3. An electromagnetic composite detection device, applied to the cable defect detection method combining electromagnetic induction and dynamic signal analysis as described in any one of claims 1-2, characterized in that, include: The system comprises a three-coil detection mechanism, a control center, and a drive mechanism; among which... The three-coil detection mechanism is arranged in an axisymmetric isoangular layout, including independently detachable detection coils and a hollowed-out housing model; The control center includes a signal receiver, a brushless motor driver board, and a microprocessor, which are used to dynamically adjust the excitation frequency and perform signal analysis. The drive mechanism includes a silicone wheel driven by a brushless motor and a driven wheel. The radius of the groove opening of the driven wheel is larger than the diameter of the cable, and a retaining edge is provided on the outside to constrain the direction of travel.

4. The electromagnetic composite detection device according to claim 3, characterized in that, The driven wheel and the silicone wheel are assembled into a coaxial structure through the wheel drive housing, and the wheel drive housing is connected to symmetrically distributed electric push rods through a damping hinge to realize the synchronous extension and retraction and angle adaptive adjustment of the pressing mechanism.

5. The electromagnetic composite detection device according to claim 4, characterized in that, The electric push rod is controlled by a remote control signal to extend and retract, thereby enabling the drive mechanism to press cables of different sizes together.

6. The electromagnetic composite detection device according to claim 3, characterized in that, The control center includes a signal conversion chip, which converts the forward and reverse signals output by the remote control into speed control commands for the brushless motor, and synchronizes defect location data and speed information in real time.

7. The electromagnetic composite detection device according to claim 3, characterized in that, The hollowed-out housing model is compatible with ultrasonic sensors and supports the expansion installation of multimodal detection modules.

8. The electromagnetic composite detection device according to claim 3, characterized in that, The detection mechanism and the drive mechanism are symmetrically distributed around the cable, and three symmetrical containment models are configured at the tail to balance the mass distribution of the device and reduce the overturning moment.

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