Hollow concrete pole detection method and system based on multi-sensor time series analysis and wave velocity self-calibration
By employing multi-sensor time-series analysis and wave velocity self-calibration, the problem of accurate non-destructive testing of underground and internal defects in hollow concrete poles was solved, achieving efficient and safe pole testing and providing accurate defect location and assessment.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SICHUAN CENTRAL INSPECTION TECHNOLOGY INC
- Filing Date
- 2026-05-19
- Publication Date
- 2026-07-07
AI Technical Summary
Existing detection methods cannot efficiently and accurately detect underground and internal defects in hollow concrete poles, and there are also safety risks and insufficient detection accuracy issues.
By employing a multi-sensor time-series analysis and wave velocity self-calibration method, sensors are placed on the exposed section of the pole to excite impact elastic waves. The wave velocity self-calibration algorithm and multi-source signal time-series analysis technology are used to establish a precise quantitative relationship between the wave velocity of the pole and the location of defects, thereby achieving non-destructive testing.
It enables intelligent quantitative detection of underground and internal defects in utility poles, improving detection accuracy and efficiency, reducing false alarm and false alarm rates, providing reliable digital data, and offering direct support for the safety assessment and maintenance of utility poles.
Smart Images
Figure CN122345656A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of hollow concrete pole testing technology, and in particular to a method and system for testing hollow concrete poles based on multi-sensor time-series analysis and wave velocity self-calibration. Background Technology
[0002] In the power and telecommunications sectors, hollow concrete utility poles (or utility poles) are crucial infrastructure. Exposed to the natural environment for extended periods, they are susceptible to damage from wind and rain, external impacts, soil erosion, and aging. This can lead to problems such as cracks, voids, and concrete deterioration, particularly in the underground sections, seriously threatening the safe operation of the power grid.
[0003] Currently, pole inspection mainly relies on manual visual inspection, which cannot detect underground parts and internal defects, resulting in poor reliability and low efficiency. Some technologies attempt to use excavation methods for inspection, but these are costly, environmentally damaging, and disruptive to power supply. In recent years, some non-destructive testing technologies have been introduced into this field, such as low-strain reflection wave testing and ultrasonic testing. However, these methods all have certain limitations. For example, low-strain reflection wave testing is difficult to effectively identify reflection signals from the pole base and internal defects, and a single sensor cannot automatically calibrate the wave velocity, making the detection accuracy highly dependent on experience. Ultrasonic testing requires high surface flatness, making it unsuitable for rapid, large-scale on-site screening, and it suffers severe attenuation and limited detection depth for non-metallic materials.
[0004] Therefore, there is an urgent need in this field for a non-destructive testing method and system for hollow concrete poles that is excavation-free, highly efficient, accurate, and adaptable to wave velocities of different materials, so as to achieve a reliable assessment of the underground part and internal defects of the poles.
[0005] The information disclosed in this background section is intended only to enhance the understanding of the overall background of the invention and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention
[0006] The purpose of this invention is to provide a technical solution that can solve the problems of low efficiency of existing detection methods, safety risks of utility poles, and inability to accurately locate underground and internal defects.
[0007] This detection technology uses a dedicated vibration device and a multi-sensor array to simultaneously test different locations on the pole. By employing a wave velocity self-calibration algorithm and multi-source signal time-series analysis technology, it establishes a precise quantitative relationship between the pole's wave velocity, the "eight"-shaped characteristics of dual-channel incident waves and dual-channel reflected waves, and the location of internal defects. This provides a novel intelligent solution for rapidly, accurately, and non-destructively assessing the internal health and underground hidden defects of hollow concrete utility poles on-site, representing a significant breakthrough in ensuring the safety and preventative maintenance of power infrastructure.
[0008] To achieve the above objectives, the present invention provides the following solution: A method for detecting hollow concrete poles based on multi-sensor time-series analysis and wave velocity self-calibration includes the following steps: Step 1: Arrange at least two sensors along the axial direction on the exposed section of the pole, namely a near-ground sensor and a far-ground sensor; Step 2: Excite an impact elastic wave at the impact point above the far-ground sensor, and simultaneously collect the time-domain signals received by the near-ground sensor and the far-ground sensor; Step 3: Calculate the take-off time difference between the elastic wave and the near-ground sensor and the far-ground sensor. Based on the take-off time difference and the known distance between the two sensors, calculate the actual propagation speed of the elastic wave in the pole. Step 4: Based on the actual propagation speed, analyze the characteristics of the reflected wavelet in the time-domain signal to determine whether there are defects inside the pole and to determine the location of the defects; The reflected wavelet characteristics include: in the signals of the near-ground sensor and the far-ground sensor, the timing of the reflected wavelet occurrence follows the rule of near first and far last, and the waveform phase changes.
[0009] Optionally, the near-first-far-later pattern is identified using a figure-eight determination algorithm, the algorithm comprising: Identify reflected sub-waves in the waveforms of the near-ground sensor and the far-ground sensor; Determine whether the arrival time T_S1 of the reflected wavelet in the near-ground sensor waveform is earlier than the arrival time T_S2 in the far-ground sensor waveform; if so, determine that the reflected wavelet satisfies the figure-eight timing criterion.
[0010] Optionally, the figure-eight determination algorithm further includes phase consistency judgment: determining whether the reflected wavelet exhibits the same phase change characteristics in the waveforms of the near-ground sensor and the far-ground sensor; wherein, the phase change characteristics include being in phase with the initial jump signal, out of phase, or having a phase shift of a fixed angle.
[0011] Optionally, a reflected wavelet that simultaneously satisfies the figure-eight timing criterion and the phase consistency condition is determined to be a valid reflected signal from the bottom of the rod or an internal defect.
[0012] Optionally, in the wave velocity self-calibration step, multiple signal acquisitions are performed, and the average value of the calculated multiple time differences is taken before calculating the wave velocity.
[0013] The detection method for hollow concrete poles based on multi-sensor time-series analysis and wave velocity self-calibration is operated according to the following steps: a. On the part of the utility pole to be tested above the ground, at least two sensor measuring points (near ground measuring point and far ground measuring point) and one excitation point are precisely arranged along the pole axis; b. Use a special excitation device to generate impact elastic waves at the excitation point, and use two sensors to synchronously collect the elastic wave signals propagating in the rod; c. Extract the take-off time of the elastic wave arriving at the two sensors of the dual channel, calculate the average time difference, and combine it with the known sensor spacing to independently calibrate the true propagation speed of the elastic wave in the pole on site; d. Based on the calibrated wave velocity, the timing characteristics and phase reversal phenomenon of the pole bottom reflection signal in the waveforms of the two sensors are analyzed to form a unique "eight"-shaped judgment criterion, which can accurately identify the position of the pole bottom; e. Based on the calibrated wave velocity and the "figure-eight" criterion, it intelligently identifies abnormal reflected waves in the waveform that are in phase with the take-off signal and have enhanced energy, and accurately locates the position of internal defects in the pole.
[0014] A detection system for hollow concrete poles based on multi-sensor time-series analysis and wave velocity self-calibration includes: Vibration excitation device, used to generate impact elastic waves at the excitation point on the surface of the pole; The sensor array includes at least two sensors for near-ground and far-ground measuring points fixed to the surface of the pole, and synchronously acquires vibration signals; The signal acquisition and analysis instrument is used to receive and store the signals from the sensor and perform wave velocity self-calibration calculation; The data processing unit has a built-in judgment algorithm for automatically identifying valid reflected signals and calculating the location of defects; The display unit is used to display the detection waveform, analysis process, and results.
[0015] Optionally, the excitation device includes a metal striking block that can be fixed to the rod and a handheld hammer.
[0016] Optionally, the system also includes a tablet computer, which is wirelessly connected to the signal acquisition and analysis host for display, control, and data analysis.
[0017] Compared with the prior art, the present invention has the following beneficial effects: (1) For the first time, intelligent quantitative detection of hidden defects in underground utility poles has been achieved: This invention overcomes the limitations of previous visual inspections that could not detect underground parts and the significant impact of wave velocity errors on traditional reflected wave methods. Through an innovative "wave velocity self-calibration" algorithm and a "figure-eight" time sequence analysis criterion, it can accurately quantify and locate defects in poles buried deep underground (the location error can be controlled within 5%), providing direct and reliable digital evidence for the safety assessment and precise maintenance of utility poles.
[0018] (2) A multi-feature fusion intelligent judgment model was established: This invention does not rely on a single signal feature, but creatively integrates multiple feature parameters such as wave velocity (V), reflected signal timing difference (Δt), and waveform phase change to construct an intrinsic and logically rigorous intelligent analysis model. This model greatly enhances anti-interference capability and the reliability of defect identification, effectively reducing false alarm rate and false negative rate.
[0019] (3) It provides a set of efficient and secure integrated solutions: This invention integrates complex non-destructive testing technology into a portable system. The testing process requires no excavation or climbing, and can be carried out only on the ground. The single-point testing time is short, which greatly improves the testing efficiency and completely eliminates the risks of working at height. It is suitable for rapid testing and management of utility poles. Attached Figure Description
[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments 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.
[0021] Figure 1 This is a schematic diagram of the detection object provided in an embodiment of the present invention.
[0022] Figure 2 This is a schematic diagram of the measurement point layout provided in an embodiment of the present invention.
[0023] Figure 3 This is a schematic diagram of the detection waveform provided in an embodiment of the present invention. Detailed Implementation
[0024] 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. 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.
[0025] The purpose of this invention is to provide a non-destructive testing method and system for hollow concrete poles that is excavation-free, highly efficient, accurate, and adaptable to wave velocities of different materials.
[0026] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.
[0027] Example 1: This implementation provides a method and system for detecting hollow concrete poles based on multi-sensor time-series analysis and wave velocity self-calibration, aiming to solve the industry problem that existing technologies cannot efficiently, accurately, and non-destructively detect underground parts and internal defects of utility poles.
[0028] The core of this technology lies in discovering and utilizing the quantifiable temporal differences and phase characteristics of the reflected signals from the pole base and defects received at different sensor locations when the impact elastic wave propagates along the axial direction of the utility pole. These temporal differences, together with the actual wave velocity of the pole body automatically calibrated through sensor spacing, constitute sensitive characteristic indicators for defect identification. By employing a "wave velocity self-calibration" algorithm and a "figure-eight" temporal judgment criterion to fuse and analyze multi-source signals, an analytical model capable of accurately retrieving the location of internal defects and the depth of the pole base is established.
[0029] The method is characterized by operating according to the following steps: S1: Measurement point layout and area definition: On the portion of the utility pole to be tested above ground, define at least two sensor installation points along the pole's axial direction: a near-ground measuring point (point 1) and a far-ground measuring point (point 0). The near-ground measuring point is located in an area 20cm to 50cm above the ground, and the far-ground measuring point is located within an axial range of 0.5m to 1.0m from the near-ground measuring point. Define an excitation point (point 3) 30cm to 50cm above the far-ground measuring point.
[0030] S2: Equipment Installation and Signal Activation: Paste and fix a special signal excitation metal block at the excitation point (point 3); apply a coupling agent and install sensors at the near-ground measurement point (point 1) and the far-ground measurement point (point 0); use a special knocking tool to vertically knock the excitation block to generate impact elastic waves; synchronously collect the stress wave signals propagating in the pole body through two sensors; repeat the above knocking and collection process no less than 5 times to obtain multiple sets of effective data.
[0031] S3: Wave velocity self-calibration calculation: Process the multiple sets of signals collected, accurately extract the starting times t1 and t2 when the elastic wave arrives at the near-ground sensor and the far-ground sensor; calculate the time difference Δt = t2 - t1 between the two starting times in each set of signals; obtain the average value ΔT of the time differences of all effective signals; calculate the true propagation velocity V = L / ΔT of the elastic wave in the telegraph pole according to the known distance L between the sensors and the average time difference ΔT.
[0032] S4: Identification and verification of the bottom reflection of the pole: Based on the calibrated wave velocity V, analyze the reflection sub-wave characteristics in the waveform after average processing, and accurately identify the bottom reflection signal of the pole through the "eight-shaped" determination algorithm: (1) Synchronously search for significant reflection sub-waves in the waveforms of the two sensors within the expected bottom reflection time window; (2) Perform the "eight-shaped" timing determination: The arrival time T_S1 of the reflection sub-wave in the waveform of the near-ground sensor must be earlier than the arrival time T_S2 in the waveform of the far-ground sensor (T_S1 < T_S2); (3) Perform the "eight-shaped" phase determination: The reflection sub-wave should exhibit the same phase change characteristics (phase inversion relative to the starting signal) in the waveforms of the two sensors; (4) Determine the reflection sub-wave that simultaneously satisfies the timing condition and the phase condition as the effective bottom reflection signal of the pole.
[0033] S5: Intelligent identification and location of defects: Based on the calibrated wave velocity V and the "eight-shaped" determination criterion, intelligently identify internal defects: (1) Within the time period before the bottom reflection of the pole, search for abnormal reflection sub-waves with the same phase (or opposite phase) as the starting signal and significantly enhanced energy; (2) Perform the same "eight-shaped" determination (timing determination T_S1 < T_S2 and phase consistency determination) on each candidate abnormal sub-wave; (3) Determine the abnormal sub-wave that satisfies all determination conditions as the defect reflection signal and record its arrival time T'; (4) Calculate the accurate position of the defect according to the formula L' = V × T' / 2 S6: Result output and storage: The system automatically generates a structured inspection report containing information such as bar wave velocity, bar base depth, defect location, and defect quantity, and stores the raw data and analysis results together.
[0034] The system is characterized by comprising the following components: (1) Vibration device: including a special metal striking block that can be glued to the rod and a hand-held force hammer, used to generate standardized impact elastic waves at the excitation point; (2) Sensor array: at least two high-precision accelerometers are used to be fixed at near-ground measuring points and far-ground measuring points respectively to synchronously collect the vibration signal of the pole; (3) Signal acquisition and analysis instrument: Portable host, used to receive, amplify, filter and acquire sensor signals at high speed, and perform wave velocity self-calibration calculation; (4) Data processing unit: It has the "eight" shaped judgment algorithm built in, including a timing judgment module and a phase analysis module, which are used to automatically identify effective reflection signals and calculate the defect location; (5) Display and human-computer interaction unit: used to display waveform signals, analysis process and detection results in real time, and supports parameter setting and data management.
[0035] This technical solution achieves accurate, efficient, and non-destructive detection of internal defects in hollow concrete utility poles through multi-sensor collaborative operation and intelligent algorithm analysis, providing reliable technical support for the safe operation and maintenance of power infrastructure.
[0036] This embodiment provides an intelligent non-destructive testing method and system for internal defects in hollow concrete utility poles based on multi-sensor wave velocity self-calibration and time-series analysis. It successfully solves the industry problems of low efficiency, safety risks, and inability to accurately locate underground and internal defects in existing testing methods. Compared with existing technologies, this invention has the following significant advantages: (1) Intelligent and precise location detection of hidden defects has been achieved: This invention, for the first time, integrates and analyzes on-site self-calibrated wave velocity (V), multi-sensor timing difference (Δt), and reflected wave phase characteristics through rigorous physical models and algorithms, establishing a high-precision defect location model (with location errors controllable within 5%). It overcomes the limitations of traditional visual inspection, which cannot detect underground portions, and the significant influence of wave velocity errors and experience on the single-sensor reflected wave method. It can directly output precise defect locations and pole base depth values, providing direct and reliable digital data for pole safety assessment and precise maintenance.
[0037] (2) The detection mechanism and algorithm are highly innovative: The invention creatively proposes a "wave velocity self-calibration" method and a "figure-eight" timing judgment criterion, accurately capturing the key spatiotemporal characteristics of stress wave propagation in the pole and reflection from the pole base / defect. This technical solution originates from the physical mechanism of wave propagation, is logically rigorous, and can automatically and objectively identify reflected signals. It represents an intelligent leap in pole inspection from "experience-based judgment" to "model-driven, data-verified" methods, exhibiting strong anti-interference capabilities and high reliability.
[0038] (3) Extremely high detection efficiency, completely non-destructive and safe: The entire inspection process does not damage the pole structure, requires no excavation or climbing, and a single inspection takes only a few minutes, far superior to destructive methods such as excavation inspection and traditional manual climbing patrols. Furthermore, this method utilizes mechanical waves for inspection, requiring operators to work only on the ground, completely eliminating the safety risks associated with working at heights and excavation, and significantly improving inspection efficiency and personnel safety.
[0039] (4) The system has a high degree of integration, good reliability, and strong adaptability: The technical solution has been thoroughly verified through field testing. The provided testing system is highly integrated, easy to operate, and exhibits good repeatability and consistency in the analysis results. Furthermore, the method is based on the fundamental physical properties of the pole, and its analysis model is well-adapted to concrete poles from different manufacturers and of different ages. It can automatically adapt to the material properties of different poles simply by performing a "wave velocity self-calibration" step, demonstrating great potential for future application.
[0040] In summary, this invention provides an efficient, accurate, non-destructive, and safe intelligent overall solution for solving the problem of non-destructive testing of the internal condition of hollow concrete utility poles. It is of great significance for ensuring the safe operation of the power grid, promoting preventive maintenance, and reducing life cycle costs. It has significant technical and economic benefits and broad application prospects.
[0041] Example 2: This embodiment presents an intelligent non-destructive testing method for internal defects in hollow concrete utility poles based on multi-sensor wave velocity self-calibration and time-series analysis. The method was applied in a practical setting along a roadside in a certain area to verify its effectiveness and accuracy in non-destructive testing of utility poles. The test object is as follows: Figure 1 During the inspection, the utility pole, located approximately 1.2 meters above the ground, had a diameter of 23 cm and no overhead power cables. Visually, approximately 10.5 meters of the pole was visible above ground, while the designed total length of the pole was 12 meters.
[0042] Detection targets and methods: Measuring point 1 is positioned 0.2m above the ground. Measuring point 0 is positioned above measuring point 1, 0.8m away from measuring point 1. Measuring point 2 is positioned above measuring point 0. The line connecting measuring points 0, 1, and 2 is parallel to the direction of the utility pole. Measuring point 2 is 0.3m away from measuring point 0. Measuring points 0 and 1 serve as signal receiving points, and measuring point 2 serves as a fixing point for the metal block. The measuring point arrangement is as follows. Figure 2 Please refer to the test waveform diagram. Figure 3 .
[0043] Detection process and data processing: Impact elastic wave testing equipment was used to excite and acquire signals from the utility pole. The typical waveforms acquired were analyzed (see...). Figure 3 The initial wave take-off time of the utility pole is extracted, and the elastic wave velocity of the utility pole is calculated by combining the distance between measuring point 0 and measuring point 1. The bottom reflection time of the utility pole is then determined by combining the phase characteristics.
[0044] Results and validation: Testing revealed a significant reflected wave from the pole's base. No obvious in-phase reinforcement signal was found between the reflected wave and the initial vibration wave signal, indicating no significant defects were found in the underground portion. Analysis and calculations determined the pole's wave velocity to be 4.257 km / s, with a buried length of 1.575 m.
[0045] Application examples demonstrate that the non-destructive testing method provided by this invention can accurately determine the wave velocity of utility poles and analyze the burial depth of the pole through the obvious reflection signal at the pole base. The testing process is fast and accurate, providing a rapid and reliable method for inspecting utility poles. The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the systems disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the descriptions are relatively simple; relevant parts can be referred to the method section.
[0046] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. Furthermore, those skilled in the art will recognize that, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.
Claims
1. A method for detecting hollow concrete poles based on multi-sensor time-series analysis and wave velocity self-calibration, characterized in that, Includes the following steps: Step 1: Arrange at least two sensors along the axial direction on the exposed section of the pole, namely a near-ground sensor and a far-ground sensor; Step 2: Excite an impact elastic wave at the impact point above the far-ground sensor, and simultaneously collect the time-domain signals received by the near-ground sensor and the far-ground sensor; Step 3: Calculate the take-off time difference between the elastic wave and the near-ground sensor and the far-ground sensor. Based on the take-off time difference and the known distance between the two sensors, calculate the actual propagation speed of the elastic wave in the pole. Step 4: Based on the actual propagation speed, analyze the characteristics of the reflected wavelet in the time-domain signal to determine whether there are defects inside the pole and to determine the location of the defects; The reflected wavelet characteristics include: in the signals of the near-ground sensor and the far-ground sensor, the timing of the reflected wavelet occurrence follows the rule of near first and far last, and the waveform phase changes.
2. The method for detecting hollow concrete poles based on multi-sensor time-series analysis and wave velocity self-calibration according to claim 1, characterized in that, The near-first-far-later pattern is identified using a figure-eight determination algorithm, which includes: Identify reflected sub-waves in the waveforms of the near-ground sensor and the far-ground sensor; Determine whether the arrival time T_S1 of the reflected wavelet in the near-ground sensor waveform is earlier than the arrival time T_S2 in the far-ground sensor waveform; if so, determine that the reflected wavelet satisfies the figure-eight timing criterion.
3. The method for detecting hollow concrete poles based on multi-sensor time-series analysis and wave velocity self-calibration according to claim 2, characterized in that, The figure-eight determination algorithm further includes phase consistency determination: determining whether the reflected wavelet exhibits the same phase change characteristics in the waveforms of the near-ground sensor and the far-ground sensor; wherein, the phase change characteristics include being in phase with the initial jump signal, out of phase, or having a phase shift of a fixed angle.
4. The method for detecting hollow concrete poles based on multi-sensor time-series analysis and wave velocity self-calibration according to claim 3, characterized in that, A reflected wavelet that simultaneously satisfies the figure-eight timing criterion and the phase consistency condition is determined to be a valid reflected signal from the bottom of the rod or an internal defect.
5. The method for detecting hollow concrete poles based on multi-sensor time-series analysis and wave velocity self-calibration according to claim 1, characterized in that, In the wave velocity self-calibration step, multiple signal acquisitions are performed, and the average value of the calculated time differences is taken before the wave velocity is calculated.
6. A detection system for implementing the detection method for hollow concrete poles based on multi-sensor time-series analysis and wave velocity self-calibration as described in any one of claims 1-5, characterized in that, include: Vibration excitation device, used to generate impact elastic waves at the excitation point on the surface of the pole; The sensor array includes at least two sensors for near-ground and far-ground measuring points fixed to the surface of the pole, and synchronously acquires vibration signals; The signal acquisition and analysis instrument is used to receive and store the signals from the sensor and perform wave velocity self-calibration calculation; The data processing unit has a built-in judgment algorithm for automatically identifying valid reflected signals and calculating the location of defects; The display unit is used to display the detection waveform, analysis process, and results.
7. The detection system according to claim 6, characterized in that, The excitation device includes a metal striking block that can be fixed to the rod and a handheld hammer.
8. The detection system according to claim 6, characterized in that, The system also includes a tablet computer, which is wirelessly connected to the signal acquisition and analysis host for display, control, and data analysis.