A method and system for simulating vibrational excitation for power transmission towers

Abstract

The application discloses a kind of simulation vibration excitation method and system for power transmission tower, belong to electric power engineering and structural health monitoring field, its method includes: obtaining tower finite element model;Deploy flexible exciter array, the array includes permanent magnet adsorption exciter unit and tunable resonance coupling layer;Determine target vibration mode, set mixed excitation parameter set;Perform target mode decoupling cooperative control, produce collaborative drive signal and excite tower;Real-time monitoring dynamic response data and carry out closed-loop control;Finally extract damage identification feature to assess structural safety.The application adopts flexible exciter array, acoustic wave-mechanical hybrid excitation and mode decoupling cooperative control technology, can realize the accurate excitation of specific vibration mode of power transmission tower, solve the problem that traditional excitation device is difficult to simulate low-frequency long-period vibration, improve the simulation fidelity of vibration excitation and the sensitivity of structural damage identification.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of power engineering and structural health monitoring, and in particular to a method and system for simulating vibration excitation of a power transmission tower. BACKGROUND

[0002] A power transmission tower is a key load-bearing structure in a power system, which is exposed to complex natural environments such as wind, rain, icing, and temperature changes for a long time, and is prone to damage such as bolt loosening, component fatigue, and material corrosion, which poses a potential threat to the safe and stable operation of the power grid. Therefore, regular structural health monitoring of the power transmission tower is crucial to ensure the safety of the power grid. As a global and non-destructive detection technology, vibration analysis assesses the overall health status by analyzing dynamic characteristic parameters such as natural frequency, mode shape, and damping ratio, and is an important means in the field of structural health monitoring.

[0003] Existing vibration testing methods for power transmission towers mainly include environmental excitation and artificial excitation. Among them, artificial excitation method applies known excitation to obtain the vibration response of the structure, so as to perform more accurate modal analysis. Common excitation devices include large inertia or electromagnetic exciters installed on the tower body, or manual hammering, rope release, even rocket excitation, etc., which apply single-point or a few-point excitation at specific positions on the tower body to excite the vibration of the structure.

[0004] However, the existing artificial excitation method has many shortcomings. Large exciter devices are heavy, difficult to install and deploy on site, and costly; the transient impact methods such as hammering and rocket excitation have a wide distribution of excitation energy in the frequency domain, making it difficult to concentrate energy to effectively excite the specific low-frequency dominant vibration mode of the tower, and the repeatability is poor. In addition, the environmental excitation method is not sensitive to high-order modes and early minor damage due to unknown and weak excitation sources, resulting in low signal-to-noise ratio of the response signal, making it difficult to accurately identify modal parameters that can reflect structural damage. SUMMARY

[0005] To solve the above problems, the present application provides a method and system for simulating vibration excitation of a power transmission tower, which adopts a flexible exciter array deployed on the surface of the tower, and through mixed excitation parameter setting and target mode decoupling cooperative control, can realize efficient and pure excitation and accurate closed-loop control of the target vibration mode, thereby improving the accuracy and reliability of structural damage identification.

[0006] The above object can be achieved by the following scheme:

[0007] A method for simulating vibration excitation of a power transmission tower, comprising: obtaining structural parameters and initial vibration response data of the power transmission tower, and generating a calibrated tower finite element model; based on the tower finite element model, planning and deploying a flexible exciter array on the surface of the power transmission tower to complete exciter array configuration, wherein the flexible exciter array comprises a plurality of exciter units fixed by permanent magnets, and each exciter unit is provided with a tunable resonance coupling layer at the bottom; obtaining test requirements to determine a target vibration mode, and setting mixed excitation parameters based on the tower finite element model and the target vibration mode to generate an excitation parameter set, wherein the target vibration mode is a specific vibration form reflecting the dynamic characteristics of the power transmission tower, and the mixed excitation parameters include resonance coupling layer tuning parameters for low-frequency vibration and exciter driving parameters for high-frequency vibration; performing target mode decoupling cooperative control according to the excitation parameter set, calculating an independent driving signal of each exciter unit through a mode control algorithm to make the exciter units cooperatively excite the target vibration mode and generate a cooperative driving signal, wherein the target mode decoupling cooperative control is to eliminate the vibration coupling effect between the exciter units; exciting the power transmission tower based on the cooperative driving signal, and monitoring dynamic response data in real time, and comparing the dynamic response data with expected responses of the target vibration mode to generate response deviation data; dynamically adjusting the excitation parameter set based on the response deviation data to realize closed-loop control; extracting damage identification features based on the dynamic response data to evaluate the structural safety of the power transmission tower, wherein the damage identification features are modal parameters for evaluating structural integrity.

[0008] Optionally, the obtaining structural parameters and initial vibration response data of the power transmission tower, and generating a calibrated tower finite element model comprises: collecting vibration signals in a natural state through sensors arranged on the power transmission tower to obtain initial vibration response data; obtaining structural parameters in combination with obtained design data of the power transmission tower; and establishing a preliminary finite element model based on the initial vibration response data and the structural parameters, and generating a calibrated tower finite element model by iterative checking of model simulation results and the initial vibration response data.

[0009] Optionally, based on the tower finite element model, planning and deploying a flexible exciter array on the surface of the power transmission tower to complete exciter array configuration comprises: performing modal analysis on the tower finite element model to determine vibration nodal point positions of the target vibration mode, and generating a deployment position plan; fixing the exciter units on the surface of the power transmission tower by permanent magnet adsorption according to the deployment position plan; and performing a function test on the installed exciter units to ensure that the array connection and communication are normal, and completing the exciter array configuration.

[0010] Optionally, the setting the excitation parameters, generating the excitation parameter set comprises: for the low frequency component of the target vibration mode, calculating and setting the resonance frequency of the tunable resonant coupling layer to generate a resonance coupling parameter; for the high frequency source providing excitation energy for the low frequency resonance of the target vibration mode, setting the driving frequency, amplitude and phase of the exciter unit to generate an exciter driving parameter; and combining the resonance coupling parameter and the exciter driving parameter to form the excitation parameter set.

[0011] Optionally, the executing the target mode decoupling cooperative control, calculating the independent driving signal of each exciter unit through a modal control algorithm to make the exciter units cooperatively excite the target vibration mode, and generating the cooperative driving signal comprises: inputting the excitation parameter set and the target vibration mode into a dynamics inverse model based on a tower finite element model; calculating the driving signal component required to be applied to each exciter unit for exciting the target vibration mode through the dynamics inverse model; and synchronously coordinating the driving signal component to ensure the phase and amplitude of the output of each unit are cooperative, and combining the driving signal component into the cooperative driving signal.

[0012] Optionally, the real-time monitoring of the dynamic response data, comparing the dynamic response data with the expected response of the target vibration mode, and generating response deviation data comprises: collecting the multi-channel vibration signals of the power transmission tower under the excitation of the cooperative driving signal in real time through a sensor network to form the dynamic response data; calculating the expected theoretical response of each sensor position based on the target vibration mode to form an expected response data set; and comparing the dynamic response data with the expected response data set in real time, quantifying the deviation, and generating the response deviation data.

[0013] Optionally, the dynamic adjustment of the excitation parameter set based on the response deviation data to achieve closed-loop control comprises: inputting the response deviation data into an adaptive control algorithm to determine whether the deviation exceeds a control threshold; if the deviation exceeds the control threshold, the adaptive control algorithm calculates an adjustment amount for correcting the current excitation parameters; applying the adjustment amount to the current excitation parameter set to generate an updated excitation parameter set, and continuing the excitation process.

[0014] Optionally, the extraction of damage identification features based on the dynamic response data and the evaluation of the structural safety of the power transmission tower comprises: performing modal parameter identification on the dynamic response data to calculate the real-time natural frequency and damping ratio of the power transmission tower; comparing the real-time natural frequency and damping ratio with the baseline values in the healthy state to extract the variation as the damage identification features; and inputting the damage identification features into a pre-trained evaluation model to output the structural safety evaluation result of the power transmission tower.

[0015] Optionally, the method further comprises: based on the structure safety evaluation result, feeding back adjustment of focusing the target vibration mode on the suspected damage area; updating the damage state of the tower finite element model according to the structure safety evaluation result; and repeatedly performing the excitation and evaluation process based on the adjusted target vibration mode and the updated tower finite element model to realize accurate positioning of the damage.

[0016] Based on the same inventive concept, the application also provides a simulated vibration excitation system for a power transmission tower, comprising: a data acquisition and finite element modeling module for acquiring structural parameters and initial vibration response data of the power transmission tower and generating a calibrated tower finite element model; a flexible array excitation module for planning and deploying a flexible exciter array on the surface of the power transmission tower based on the tower finite element model, and completing exciter array configuration, wherein the flexible exciter array comprises a plurality of exciter units fixed by permanent magnets, and each exciter unit is provided with a tunable resonance coupling layer at the bottom; an excitation parameter generation module for acquiring test requirements to determine a target vibration mode, and setting mixed excitation parameters based on the tower finite element model and the target vibration mode to generate an excitation parameter set, wherein the target vibration mode is a specific vibration mode reflecting the dynamic characteristics of the power transmission tower, and the mixed excitation parameters include resonance coupling layer tuning parameters for low-frequency vibration and exciter driving parameters for high-frequency vibration; a mode decoupling cooperative control module for performing target mode decoupling cooperative control according to the excitation parameter set, calculating an independent driving signal of each exciter unit through a mode control algorithm, and making the exciter units cooperatively excite the target vibration mode to generate a cooperative driving signal, wherein the target mode decoupling cooperative control is to eliminate the vibration coupling effect between the exciter units; a dynamic response monitoring module for exciting the power transmission tower based on the cooperative driving signal and monitoring dynamic response data in real time, and comparing the dynamic response data with the expected response of the target vibration mode to generate response deviation data; a closed-loop feedback adjustment module for dynamically adjusting the excitation parameter set based on the response deviation data to realize closed-loop control; and a structure damage evaluation module for extracting damage identification features based on the dynamic response data and evaluating the structural safety of the power transmission tower, wherein the damage identification features are modal parameters for evaluating the structural integrity.

[0017] Compared with the prior art, the application has the following advantages:

[0018] 1. The application deploys a flexible exciter array with a tunable resonance coupling layer on the surface of the power transmission tower, sets mixed excitation parameters including resonance coupling layer tuning parameters and exciter driving parameters, efficiently couples high-frequency excitation energy to the low-frequency target vibration mode of the tower, effectively solves the problem that small exciter is difficult to effectively excite large structures, and improves the excitation efficiency and mode purity.

[0019] 2、The application realizes accurate closed-loop control of the entire excitation process by monitoring dynamic response data in real time and comparing with the expected response of the target mode, generating response deviation data, and dynamically adjusting the excitation parameter set based on the deviation data, which can compensate for vibration deviation caused by model errors, environmental interference or structural nonlinearities in real time, ensuring high-fidelity reproduction of actual vibration to target vibration mode, and improving the accuracy and stability of the entire test process.

[0020] 3、Based on the high signal-to-noise ratio dynamic response data obtained under precise controlled excitation, the extracted modal parameters are more sensitive and reliable as damage identification features, improving the identification ability of early structural damage, and combining with the pre-trained evaluation model, realizing the automation and intelligent evaluation of the safety of the tower structure, providing an objective and scientific basis for the operation and maintenance decision of the transmission tower.

[0021] Other features and advantages of the present application will be set forth in the following description, and in part will become apparent to those skilled in the art from the description, or can be learned by practice of the application. The objects and other advantages of the present application can be realized and achieved by the structures indicated in the specification, claims and drawings. BRIEF DESCRIPTION OF DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or prior art description will be briefly introduced below. Obviously, the drawings in the following description are some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without creative labor.

[0023] Figure 1 is a flowchart of a simulation vibration excitation method for a transmission tower according to an embodiment of the present application.

[0024] Figure 2 is a finite element model checking error comparison chart of a tower according to an embodiment of the present application.

[0025] Figure 3 is a target modal response deviation closed-loop control effect chart according to an embodiment of the present application.

[0026] Figure 4 is a structural schematic diagram of a simulation vibration excitation system for a transmission tower according to an embodiment of the present application. DETAILED DESCRIPTION

[0027] In order to make the purposes, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0028] With reference to Figure 1 An embodiment of the present application provides a method for simulating vibration excitation of a power transmission tower. The method adopts a flexible exciter array, an acoustic-mechanical hybrid excitation and a modal decoupling cooperative control technology, can realize efficient and pure excitation and accurate closed-loop control of specific vibration modes of the power transmission tower, solves the problem that a traditional excitation device is difficult to simulate low-frequency and long-period vibration, and improves the simulation fidelity of vibration excitation and the accuracy and reliability of structural damage identification.

[0029] The method specifically includes the following steps.

[0030] Obtaining structural parameters and initial vibration response data of the power transmission tower, and generating a calibrated tower finite element model;

[0031] Based on the tower finite element model, a flexible exciter array is planned and deployed on the surface of the power transmission tower to complete exciter array configuration. The flexible exciter array includes a plurality of exciter units fixed by permanent magnets, and each exciter unit is provided with a tunable resonance coupling layer at the bottom.

[0032] Obtaining test requirements to determine a target vibration mode, and setting hybrid excitation parameters based on the tower finite element model and the target vibration mode to generate an excitation parameter set. The target vibration mode is a specific vibration form reflecting the dynamic characteristics of the power transmission tower, and the hybrid excitation parameters include resonance coupling layer tuning parameters for low-frequency vibration and exciter driving parameters for high-frequency vibration.

[0033] According to the excitation parameter set, target modal decoupling cooperative control is performed. A modal control algorithm is used to calculate an independent driving signal of each exciter unit, so that the exciter units cooperatively excite the target vibration mode to generate a cooperative driving signal. The target modal decoupling cooperative control is used to eliminate the vibration coupling effect between the exciter units.

[0034] Based on the cooperative driving signal, the power transmission tower is excited, and dynamic response data is monitored in real time. The dynamic response data is compared with expected response of the target vibration mode to generate response deviation data.

[0035] Based on the response deviation data, the excitation parameter set is dynamically adjusted to realize closed-loop control.

[0036] extract damage identification features based on the dynamic response data, and evaluate the structural safety of the power transmission tower, wherein the damage identification features are modal parameters used for evaluating structural integrity.

[0037] Specifically, a high-fidelity tower finite element model is constructed as a digital foundation by combining the actual vibration data of the power transmission tower with the design parameters. Based on this model, an innovative hybrid excitation strategy is used to apply controllable vibrations by deploying an array of flexible exciters fixed by permanent magnets on the surface of the tower. The core of this strategy is the tunable resonant coupling layer at the bottom of each exciter unit, which is tuned to resonate with the target low-frequency vibration mode of the power transmission tower, while the exciter itself is driven at a high frequency with high efficiency. Through this coupling layer, the energy is efficiently converted into low-frequency resonance of the structure. In order to accurately reproduce a single, pure target vibration mode and eliminate mutual interference between each excitation point, a target mode decoupling cooperative control algorithm is used to calculate the independent driving signals required for each exciter unit, enabling the entire array to work cooperatively. At the same time, by monitoring the actual vibration response of the structure in real time and comparing it with the expected response of the target mode, a deviation signal is formed, and closed-loop feedback control is realized to dynamically adjust the excitation parameters to eliminate the deviation. Finally, the inherent modal parameters of the structure are extracted from this high-purity controlled vibration response data as damage identification features, thereby evaluating the structural safety of the power transmission tower.

[0038] Optionally, the obtaining of the structural parameters and initial vibration response data of the power transmission tower and the generation of the calibrated tower finite element model comprise:

[0039] The initial vibration response data is obtained by deploying sensors on the power transmission tower to collect vibration signals in the natural state;

[0040] Specifically, by pre-deploying a sensor array, such as an acceleration sensor or a strain gauge, at key structural locations on the power transmission tower, vibration signals of the power transmission tower under natural environmental excitations such as wind load and ground microseismicity are collected. These long-term collected, weak vibration signals constitute the initial vibration response data containing the real dynamic information of the structure.

[0041] The structural parameters are obtained by combining the obtained design data of the power transmission tower;

[0042] Specifically, by consulting the design drawings, completion materials, and material performance reports of the power transmission tower, detailed structural parameters are obtained, including but not limited to the geometric dimensions of each component of the tower body, the elastic modulus, Poisson's ratio, and density of the material, as well as the stiffness characteristics of the connection nodes and the constraint conditions of the foundation.

[0043] A preliminary finite element model is established based on the initial vibration response data and structural parameters, and is iteratively checked by comparing the model simulation results with the initial vibration response data to generate a calibrated tower finite element model.

[0044] Specifically, a preliminary finite element model is constructed according to the obtained structural parameters by using a commercial finite element analysis software. The preliminary model is only a theoretical digital representation and has differences from the actual structure. In order to eliminate such differences, model calibration is needed. The calibration process processes the collected initial vibration response data, and identifies the modal parameters such as natural frequencies and vibration modes of the actual power transmission tower by modal analysis technology. The measured modal parameters are compared with the modal parameters obtained by simulation calculation of the preliminary finite element model, and a target function is established to quantify the error between them, such as an error function which can be expressed as:

[0045] ;

[0046] wherein, represents the natural frequencies of each order calculated by the finite element model, represents the measured natural frequencies of the corresponding order identified by the initial vibration response data. By repeatedly iterating and correcting the key structural parameters in the finite element model, such as material elastic modulus, node connection stiffness or foundation constraint stiffness, etc., until the value of the target function converges to within a preset minimum threshold. The iteration optimization process is essentially to make the dynamic behavior of the model infinitely approach the dynamic behavior of the real structure. Finally, when the model simulation results are highly consistent with the initial vibration response data, the obtained model is the calibrated tower finite element model, which provides a high-fidelity digital basis for subsequent exciter array deployment planning and excitation control. The checking results of the relative error of different modal order frequencies are shown in Figure 2 , which demonstrates the effectiveness of the model calibration process.

[0047] Optionally, based on the tower finite element model, a flexible exciter array is planned and deployed on the surface of the power transmission tower to complete the exciter array configuration, including:

[0048] modal analysis is performed on the tower finite element model to determine the vibration saddle point position of the target vibration mode, and a deployment position planning is generated;

[0049] Specifically, a thorough dynamic characteristic analysis is conducted using a calibrated finite element model of the transmission tower. Modal analysis is performed on the model within the finite element software environment to solve the eigenvalue problem of the structure's undamped free vibration. The analysis calculates a series of natural frequencies of the transmission tower and their corresponding vibration modes, i.e., mode shapes. Each mode shape describes the relative displacement distribution of all points on the structure when it vibrates at a specific natural frequency. After selecting one or more target vibration modes according to the experimental requirements, the corresponding mode shape vectors are analyzed in detail. The vibration midpoint, as a key physical location in a mode shape, refers to the point where the vibration displacement amplitude reaches its maximum under a specific mode. By visualizing the mode shapes through post-processing or directly retrieving the maximum value in the mode shape vector, the specific spatial coordinates of the vibration midpoint of each target vibration mode on the tower can be accurately located. Compiling these coordinate points generates a detailed deployment location planning map.

[0050] According to the deployment location plan, the exciter unit is fixed to the surface of the transmission tower by means of permanent magnet adsorption;

[0051] Specifically, based on this deployment plan, on-site staff transported each individual vibrator unit to its designated location on the transmission tower. Each vibrator unit has a high-strength permanent magnet integrated at its bottom, allowing it to be directly attracted and firmly fixed to the surface of the steel structure components of the tower without drilling or welding, achieving rapid and non-destructive installation.

[0052] Perform functional tests on the installed exciter unit to ensure that the array connection and communication are normal, and complete the exciter array configuration.

[0053] Specifically, after all exciter units are deployed as planned, a final functional test is conducted. This test includes checking the communication links between all units and the central control system to ensure they are working properly, verifying the stability of the power supply, and sending a simple test command to each unit to confirm its normal response. This ensures the entire flexible exciter array operates in good working order, thus completing the exciter array configuration.

[0054] Optionally, setting the hybrid excitation parameters and generating the excitation parameter set includes:

[0055] For the low-frequency components of the target vibration mode, the resonant frequency of the tunable resonant coupling layer is calculated and set, and resonant coupling parameters are generated.

[0056] Specifically, one or more specific target vibration modes are identified from the experimental requirements to serve as the excitation objects. These target vibration modes and their corresponding natural frequencies are obtained by analyzing a calibrated finite element model of the tower. A hybrid excitation strategy is adopted, which combines low-frequency resonance with high-frequency drive. For the low-frequency components of the target vibration modes, i.e., their inherent vibration frequencies, the parameters of the tunable resonant coupling layer at the bottom of each exciter unit need to be set. This coupling layer can be regarded as an adjustable second-order vibration system, whose own resonant frequency... Its equivalent stiffness can be adjusted and equivalent quality To change, the relationship can be represented as:

[0057] ;

[0058] in, The resonant frequency of the resonant coupling layer. For its adjustable equivalent stiffness, Its equivalent quality. Through calculation, each coupling layer... By adjusting the coupling layer to perfectly match the natural frequency of the target vibration mode, the coupling layer can resonate with the tower structure during subsequent excitation, greatly improving energy transfer efficiency. This series of adjustment parameters together constitutes the resonant coupling parameters.

[0059] For the target vibration mode being a high-frequency source that provides excitation energy for low-frequency resonance, the driving frequency, amplitude, and phase of the exciter unit are set to generate the exciter driving parameters;

[0060] Specifically, for the high-frequency source providing the core driving energy for this low-frequency resonance—the exciter unit itself—driving parameters need to be set. This includes selecting a driving frequency that is much higher than the target modal frequency and located within the exciter's efficient operating range, and setting the driving amplitude and driving phase of each exciter unit according to the mode shape vector of the target vibration mode. The driving amplitude determines the magnitude of the input energy, while the setting of the driving phase ensures that the synergistic effect of all exciter units in the array can effectively synthesize the shape of the target vibration mode, avoiding energy dissipation. These settings for driving frequency, amplitude, and phase constitute the exciter driving parameters.

[0061] The resonant coupling parameters and the exciter driving parameters are combined to form an excitation parameter set.

[0062] Specifically, the resonant coupling parameters calculated for all exciter units will be combined with the exciter drive parameters to form a complete, multi-dimensional set of excitation parameters, providing precise input commands for subsequent coordinated control.

[0063] Optionally, the execution of target mode decoupling cooperative control, which calculates the independent drive signal for each exciter unit through a modal control algorithm, enables the exciter units to cooperatively excite the target vibration mode and generate a cooperative drive signal, includes:

[0064] The excitation parameter set and target vibration modes are input into the inverse dynamic model based on the tower finite element model;

[0065] Specifically, a dynamic inverse model is established based on a calibrated finite element model of the tower. The excitation parameter set and the selected target vibration mode are provided as inputs to this dynamic inverse model.

[0066] The driving signal component required to be applied to each exciter unit to excite the target vibration mode is calculated using the inverse dynamic model.

[0067] Specifically, the traditional forward dynamics model predicts the vibration response of a structure based on the applied excitation force, while the inverse dynamics model does the opposite. Based on the desired vibration response—that is, the vibration mode shape, frequency, and amplitude of the target vibration mode—it works backwards to determine what excitation force needs to be applied at a specific location to achieve this response. This process is described by the structure's dynamic equations:

[0068] ;

[0069] in, It is the driving force vector acting on the location of the exciter unit that needs to be calculated. , and These are the mass matrix, damping matrix, and stiffness matrix extracted from the finite element model of the tower, respectively. The expected displacement response vector, first and second derivatives, are defined by the target vibration mode. and These are the desired velocity and acceleration response vectors, respectively. These desired responses are calculated based on the target frequency and amplitude set in the excitation parameter set, combined with the mode shape vector of the target vibration mode. By solving this equation, the inverse dynamic model can calculate the ideal drive signal components required to be applied to each exciter unit in the array to accurately reproduce the target vibration mode. These components naturally contain the accurate amplitude and phase relationships required to achieve modal decoupling.

[0070] The driving signal components are synchronized and coordinated to ensure that the phase and amplitude of the output of each unit are coordinated and combined into a coordinated driving signal.

[0071] Specifically, all the calculated independent drive signal components are synchronized and coordinated. A high-precision clock signal ensures that the signals of all channels are strictly aligned at output. These parallel signal streams are then integrated into a set of multi-channel collaborative drive signals, which are directly used to drive the flexible exciter array.

[0072] Optionally, the real-time monitoring of dynamic response data, and the comparison of the dynamic response data with the expected response of the target vibration mode to generate response deviation data, includes:

[0073] The sensor network is used to collect multi-channel vibration signals of the transmission tower under the excitation of the coordinated drive signal in real time, and to form dynamic response data.

[0074] Specifically, this relies on a sensor network deployed at key locations on the transmission tower structure. This network, connected to data acquisition, captures the tower's vibration in real time under the excitation of a coordinated drive signal. The analog signals from each sensor are converted into digital signals at a high sampling rate, forming a multi-channel dynamic response data stream. This data accurately reflects the actual vibration state of the transmission tower under the current excitation.

[0075] Based on the target vibration mode, the expected theoretical response at each sensor location is calculated to form an expected response dataset;

[0076] Specifically, based on the determined target vibration modes, theoretical calculations are performed to determine the expected response. This applies to any sensor measurement point. The expected theoretical response under the target vibration mode The calculation formula is:

[0077] ;

[0078] in, It is the target vibration amplitude of this mode, a constant set according to the test requirements. It is the component of the mode shape vector of the target vibration mode at the measuring point i. This value is obtained directly from the modal analysis results of the calibrated tower finite element model. It is the natural frequency of the target vibration mode, which is also determined by model analysis or experimental requirements. Represents time, This is the initial phase. By applying this formula to each sensor location, it is possible to generate a dataset of expected responses that is synchronized in time and structurally corresponding to the real-time dynamic response data.

[0079] The dynamic response data is compared with the expected response dataset in real time to quantify the deviation and generate response deviation data.

[0080] Specifically, in a continuous loop, the real-time acquired dynamic response data is compared point by point with the synchronously generated expected response dataset. The difference between the two is usually quantified by a simple subtraction operation, thereby generating response deviation data. :

[0081] ;

[0082] in, This is the dynamic response data measured in real time by the sensor at measuring point i. This series of deviation data dynamically reflects the degree of distortion between the actual vibration and the target vibration, and is output to the closed-loop feedback adjustment module in real time.

[0083] Optionally, dynamically adjusting the excitation parameter set based on the response deviation data to achieve closed-loop control includes:

[0084] The response deviation data is input into the adaptive control algorithm to determine whether the deviation exceeds the control threshold.

[0085] Specifically, the real-time generated response deviation data is used as the core input and fed into a preset adaptive control algorithm. The algorithm first judges the magnitude of the input response deviation data and compares it with a pre-set control threshold. The control threshold defines an acceptable error range; if the deviation is less than the threshold, the current excitation effect is considered good, and no adjustment is needed.

[0086] If the control threshold is exceeded, the adaptive control algorithm calculates the adjustment amount used to correct the current excitation parameters;

[0087] Specifically, if the response deviation data exceeds the control threshold, it indicates that the actual vibration has deviated from the target vibration mode, at which point the adaptive control algorithm is activated. The algorithm calculates the adjustment amount used to correct the current excitation parameters based on the magnitude, trend, and historical accumulation of the response deviation data. For example, a proportional-integral-derivative controller can be used as the adaptive control algorithm here, and the output adjustment amount... Represented as

[0088] ;

[0089] in, It is the calculated adjustment vector, which corresponds to the modifications that need to be made to the set of excitation parameters. It is the input response deviation data vector. , , These are the pre-tuned proportional, integral, and derivative gain coefficients, which determine the strength of the controller's response to current error, cumulative error, and future error trends.

[0090] The adjustment amount is applied to the current set of excitation parameters to generate an updated set of excitation parameters, and the excitation process continues.

[0091] Specifically, adjustment amount The current set of excitation parameters is applied, for example, through vector addition or multiplication correction, to generate an updated set of excitation parameters. This new set of parameters is then immediately used for the generation and output of the excitation signal at the next moment. The entire process forms a continuous feedback, calculation, and correction closed loop, dynamically pulling the vibration response of the transmission tower back to the expected target trajectory. Figure 3 As shown, the closed-loop control effect on the deviation of the target vibration modal response during the excitation process is demonstrated, and the deviation signal is rapidly suppressed under the action of the adaptive control algorithm.

[0092] Optionally, the structural safety of transmission towers can be assessed by extracting damage identification features based on dynamic response data, including:

[0093] Modal parameter identification is performed on the dynamic response data to calculate the real-time natural frequency and damping ratio of the transmission tower;

[0094] Specifically, in-depth analysis is conducted using dynamic response data obtained under precise excitation. The acquired high signal-to-noise ratio dynamic response data is input into modal parameter identification algorithms, such as frequency domain decomposition or random subspace methods. These algorithms, through mathematical transformation and processing of multi-channel vibration signals, can accurately calculate the real-time natural frequency and damping ratio of the transmission tower under the current excitation state. These modal parameters are intrinsic indicators reflecting the overall dynamic characteristics of the structure and are extremely sensitive to changes in the structure's physical properties.

[0095] The real-time natural frequency and damping ratio are compared with the baseline value under healthy conditions, and the change is extracted as a damage identification feature.

[0096] Specifically, the identified real-time natural frequencies and damping ratios are compared with a pre-established benchmark value. This benchmark value is typically the modal parameters measured and identified using the same method when the transmission tower is confirmed to be in a healthy state. By calculating the relative change between the real-time values ​​and the benchmark value, damage identification features that indicate changes in structural state can be extracted. The frequency change rate of the i-th mode... Represented as:

[0097] ;

[0098] in, It is the reference natural frequency of the i-th mode under healthy conditions. This represents the natural frequency of the i-th modal currently identified in real time. Similarly, the rate of change of the damping ratio can be calculated. These changes constitute the damage identification feature vector used for damage assessment.

[0099] The damage identification features are input into a pre-trained evaluation model, which outputs the structural safety assessment results of the transmission tower.

[0100] Specifically, the damage identification feature vector, which contains variations in multiple modal parameters, is input into a pre-trained evaluation model. This evaluation model is a classifier or regressor built using machine learning algorithms such as expert systems, neural networks, or support vector machines. It has been trained and learned using a large amount of data on healthy and damaged towers of varying degrees. After receiving the damage identification features, the model directly outputs quantitative or qualitative safety assessment results for the transmission tower structure based on its internally established complex mapping relationships. These results may include levels such as "safe," "caution," or "hazard," or specific damage probabilities, locations, and degrees.

[0101] Optionally, the method further includes:

[0102] Based on the structural safety assessment results, the target vibration modes are adjusted to focus on the suspected damage area.

[0103] Specifically, based on the information about suspected damage areas provided by the structural safety assessment results, the excitation strategy is adjusted accordingly. Specifically, the process returns to the calibrated finite element model of the tower to analyze vibration modes with high strain energy density or significant vibrational displacement within the suspected damage area. These are typically higher-order, more localized vibration modes, and they are more sensitive to changes in local stiffness. One or more of these modes are selected as new, adjusted target vibration modes, with the aim of more concentratedly projecting excitation energy onto the suspected damage area to amplify the impact of damage on the dynamic response.

[0104] The finite element model of the tower is updated to simulate the damage state based on the structural safety assessment results.

[0105] Specifically, based on the inferences about the type and extent of damage from the preliminary assessment results, the finite element model of the tower is modified to update the model to simulate the damage state. For example, if a bolt is suspected to be loose, the stiffness parameter of the corresponding connection element in the model is reduced; if a crack is suspected in the component, it is simulated by reducing the element cross-section or lowering the material's elastic modulus. This results in an updated finite element model of the tower that incorporates hypothetical damage.

[0106] Based on the adjusted target vibration modes and the updated tower finite element model, the excitation and evaluation process is repeated to achieve precise damage localization.

[0107] Specifically, based on the adjusted target vibration mode and the updated tower finite element model, the excitation and evaluation process is repeated in its entirety, including regenerating the excitation parameter set, implementing coordinated excitation control, collecting dynamic response data, and conducting a new round of modal parameter identification and safety assessment. By comparing the actual modal parameter changes obtained from this excitation test with the modal parameter changes predicted by the updated tower finite element model, the accuracy of the damage hypothesis can be verified. If the two match, it proves that the judgment of the damage location and extent is correct; if they do not match, the damage simulation parameters in the finite element model are further adjusted, and the excitation and evaluation cycle is repeated until the simulation results of the model highly match the experimental results, thereby completing the precise location and quantification of the damage.

[0108] Based on the same inventive concept, such as Figure 4 As shown, the present invention also provides a simulated vibration excitation system for transmission towers, the system comprising:

[0109] The data acquisition and finite element modeling module is used to acquire the structural parameters and initial vibration response data of the transmission tower and generate a calibrated finite element model of the tower.

[0110] The flexible array excitation module is used to plan and deploy a flexible exciter array on the surface of the transmission tower based on the finite element model of the tower, and complete the configuration of the exciter array. The flexible exciter array includes multiple exciter units fixed by permanent magnets, and each exciter unit is provided with a tunable resonant coupling layer at the bottom.

[0111] The excitation parameter generation module is used to obtain test requirements to determine the target vibration mode, and based on the tower finite element model and the target vibration mode, set hybrid excitation parameters to generate an excitation parameter set. The target vibration mode is a specific vibration pattern that reflects the dynamic characteristics of the transmission tower. The hybrid excitation parameters include resonant coupling layer tuning parameters for low-frequency vibration and exciter drive parameters for high-frequency vibration.

[0112] The modal decoupling cooperative control module is used to execute target modal decoupling cooperative control according to the excitation parameter set. It calculates the independent drive signal of each exciter unit through the modal control algorithm, so that the exciter units can cooperatively excite the target vibration mode and generate a cooperative drive signal. The target modal decoupling cooperative control is to eliminate the vibration coupling effect between the exciter units.

[0113] The dynamic response monitoring module is used to excite the transmission tower based on the cooperative drive signal and monitor the dynamic response data in real time. At the same time, it compares the dynamic response data with the expected response of the target vibration mode to generate response deviation data.

[0114] The closed-loop feedback adjustment module is used to dynamically adjust the excitation parameter set based on the response deviation data to achieve closed-loop control;

[0115] The structural damage assessment module is used to extract damage identification features based on the dynamic response data and assess the structural safety of the transmission tower, wherein the damage identification features are modal parameters used to assess structural integrity.

[0116] To verify the feasibility of this invention in practice, it was applied to the structural health assessment of an in-service 220kV transmission tower. Transmission towers operate in complex environments for extended periods, requiring precise assessment of their structural safety. Traditional manual inspections are inefficient and struggle to detect early, minor damage, while passive monitoring methods based on natural environmental excitation suffer from low signal-to-noise ratios and unreliable assessment results. This invention is applied to this tower to achieve active, controllable vibration excitation and high-precision damage assessment.

[0117] To verify the effectiveness of the invention, a complete three-day test was conducted on the 220kV transmission tower. The test process covered the entire process from finite element model calibration, exciter array deployment, target modal excitation, closed-loop control to the final structural safety assessment, and key data at each stage were recorded. The experimental objective was to accurately excite the first two bending vibration modes of the tower and assess its structural health based on these modes.

[0118] In this embodiment, the invention first collects 24-hour initial vibration response data of the tower under natural wind load using accelerometers pre-installed on the tower body. Combining the structural parameters obtained from the tower's design drawings and as-built documentation, a preliminary finite element model is established. By comparing the modal parameters calculated from the model simulation with the measured data, the equivalent stiffness of the connection nodes in the model is iteratively corrected, ultimately generating a calibrated finite element model of the tower. The errors between the natural frequencies of each order of the calibrated model and the measured values ​​are all less than 2%, laying the foundation for subsequent precise excitation.

[0119] Modal analysis was performed based on the calibrated finite element model, determining the vibration midpoints of the first and second order bending vibration modes, located at heights of 18 meters and 38 meters on the tower, respectively. Following this plan, a flexible exciter array containing 16 exciter units was non-destructively installed at the designated locations using permanent magnets. The first order bending mode was excited to the test target at a frequency of 1.18 Hz. Hybrid excitation parameters were set: the resonant frequency of the tunable resonant coupling layer at the bottom of all exciter units was tuned to 1.18 Hz; simultaneously, the driving frequency of the exciter units was set to 120 Hz, and the driving amplitude and phase of each unit were calculated based on the target mode shape vector, forming a complete set of excitation parameters.

[0120] During the excitation process, target mode decoupling and cooperative control were implemented, and multi-channel cooperative drive signals were generated through dynamic inverse model calculation based on the finite element model. At the initial stage of excitation, a deviation between the actual vibration response and the expected response of the target mode was detected due to a sudden crosswind disturbance. Closed-loop feedback regulation input this response deviation data into the adaptive PID control algorithm to calculate the adjustment amount of the excitation parameters. The excitation amplitude and phase were dynamically fine-tuned; for example, the drive amplitude of the windward exciter was increased by 4%. After approximately 5 seconds of adjustment, the response deviation was successfully suppressed to within 2%, ensuring high fidelity of the vibration excitation.

[0121] Under stable and controlled excitation, 15 minutes of high signal-to-noise ratio dynamic response data were collected, and simulated mode parameter identification was performed. The identification results showed that the real-time natural frequency of the first bending mode of the tower was 1.16 Hz. Comparing this data with the baseline value under healthy tower conditions, the frequency was calculated to have decreased by approximately 1.69%. This frequency change was used as a core damage identification feature and input into a pre-trained structural safety assessment model. After comprehensive analysis, the assessment model output an assessment result of "Caution," indicating that the damage may have originated from a slight loosening of the tower base connecting bolts. Based on this result, the maintenance team conducted a focused inspection of the tower base, identified and tightened several loose bolts, effectively eliminating potential safety hazards.

[0122] It should be noted that the electrical connections between the various units described above do not necessarily represent direct or indirect connections. Any indirect connection method can be applied to the embodiments of the present invention as long as it achieves the purpose of the present invention. The above descriptions are merely exemplary embodiments of the present invention and should not be construed as limiting the scope of the present invention.

[0123] All 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 other embodiments of this invention upon considering the specification and the disclosure of practical truth. This application is intended to cover any variations, uses, or adaptations of this invention that follow the general principles of this invention and include common knowledge or conventional techniques in the art not described herein.

Claims

1. A method for simulating vibration excitation for transmission towers, characterized in that, The method includes: Obtain the structural parameters and initial vibration response data of the transmission tower, and generate a calibrated finite element model of the tower; Based on the finite element model of the tower, a flexible exciter array is planned and deployed on the surface of the transmission tower to complete the configuration of the exciter array. The flexible exciter array includes multiple exciter units fixed by permanent magnets, and each exciter unit has a tunable resonant coupling layer at the bottom. The test requirements are obtained to determine the target vibration mode. Based on the finite element model of the tower and the target vibration mode, hybrid excitation parameters are set to generate an excitation parameter set. The target vibration mode is a specific vibration pattern reflecting the dynamic characteristics of the transmission tower. The hybrid excitation parameters include resonant coupling layer tuning parameters for low-frequency vibration and exciter drive parameters for high-frequency vibration. Setting the hybrid excitation parameters and generating the excitation parameter set includes: calculating and setting the resonant frequency of the tunable resonant coupling layer for the low-frequency component of the target vibration mode to generate resonant coupling parameters; setting the drive frequency, amplitude, and phase of the exciter unit for the high-frequency source that provides excitation energy for the low-frequency resonance of the target vibration mode to generate exciter drive parameters; and combining the resonant coupling parameters and the exciter drive parameters to form the excitation parameter set. Based on the excitation parameter set, target mode decoupling cooperative control is executed. The independent driving signal of each exciter unit is calculated through the modal control algorithm, so that the exciter units can cooperatively excite the target vibration mode and generate a cooperative driving signal. The target mode decoupling cooperative control is to eliminate the vibration coupling effect between exciter units. The transmission tower is excited based on the aforementioned collaborative drive signal, and the dynamic response data is monitored in real time. At the same time, the dynamic response data is compared with the expected response of the target vibration mode to generate response deviation data. Closed-loop control is achieved by dynamically adjusting the excitation parameter set based on the response deviation data. Damage identification features are extracted based on the dynamic response data to assess the structural safety of the transmission tower, wherein the damage identification features are modal parameters used to assess structural integrity.

2. The simulated vibration excitation method for transmission towers according to claim 1, characterized in that, The process of acquiring the structural parameters and initial vibration response data of the transmission tower and generating a calibrated finite element model of the tower includes: By deploying sensors on transmission towers, vibration signals under natural conditions are collected to obtain initial vibration response data; Based on the obtained design data of the transmission towers, the structural parameters were obtained; A preliminary finite element model is established based on the initial vibration response data and structural parameters. The model simulation results are then compared with the initial vibration response data for iterative verification, resulting in a calibrated tower finite element model.

3. The simulated vibration excitation method for transmission towers according to claim 1, characterized in that, Based on the finite element model of the transmission tower, a flexible exciter array is planned and deployed on the surface of the transmission tower. The configuration of the exciter array includes: Modal analysis is performed on the finite element model of the tower to determine the location of the vibration core of the target vibration mode and generate a deployment location plan. According to the deployment location plan, the exciter unit is fixed to the surface of the transmission tower by means of permanent magnet adsorption; Perform functional tests on the installed exciter unit to ensure that the array connection and communication are normal, and complete the exciter array configuration.

4. The simulated vibration excitation method for transmission towers according to claim 1, characterized in that, The execution of target mode decoupling cooperative control involves calculating the independent drive signal for each exciter unit using a modal control algorithm, enabling the exciter units to collaboratively excite the target vibration mode and generate a cooperative drive signal, including: The excitation parameter set and target vibration modes are input into the inverse dynamic model based on the tower finite element model; The driving signal component required to be applied to each exciter unit to excite the target vibration mode is calculated using the inverse dynamic model. The driving signal components are synchronized and coordinated to ensure that the phase and amplitude of the output of each unit are coordinated and combined into a coordinated driving signal.

5. The simulated vibration excitation method for transmission towers according to claim 1, characterized in that, The real-time monitoring of dynamic response data, and the comparison of the dynamic response data with the expected response of the target vibration mode to generate response deviation data, include: The sensor network is used to collect multi-channel vibration signals of the transmission tower under the excitation of the coordinated drive signal in real time, and to form dynamic response data. Based on the target vibration mode, the expected theoretical response at each sensor location is calculated to form an expected response dataset; The dynamic response data is compared with the expected response dataset in real time to quantify the deviation and generate response deviation data.

6. The simulated vibration excitation method for transmission towers according to claim 1, characterized in that, Dynamically adjusting the excitation parameter set based on the response deviation data to achieve closed-loop control includes: The response deviation data is input into the adaptive control algorithm to determine whether the deviation exceeds the control threshold. If the control threshold is exceeded, the adaptive control algorithm calculates the adjustment amount used to correct the current excitation parameters; The adjustment amount is applied to the current set of excitation parameters to generate an updated set of excitation parameters, and the excitation process continues.

7. The simulated vibration excitation method for transmission towers according to claim 1, characterized in that, Based on damage identification features extracted from dynamic response data, the structural safety of transmission towers is assessed, including: Modal parameter identification is performed on the dynamic response data to calculate the real-time natural frequency and damping ratio of the transmission tower; The real-time natural frequency and damping ratio are compared with the baseline value under healthy conditions, and the change is extracted as a damage identification feature. The damage identification features are input into a pre-trained evaluation model, which outputs the structural safety assessment results of the transmission tower.

8. The simulated vibration excitation method for transmission towers according to claim 7, characterized in that, The method further includes: Based on the structural safety assessment results, the target vibration modes are adjusted to focus on the suspected damage area. The finite element model of the tower is updated to simulate the damage state based on the structural safety assessment results. Based on the adjusted target vibration modes and the updated tower finite element model, the excitation and evaluation process is repeated to achieve precise damage localization.

9. A simulated vibration excitation system for transmission towers, characterized in that, The system is used for a simulated vibration excitation method for transmission towers as described in any one of claims 1-8, the system comprising: The data acquisition and finite element modeling module is used to acquire the structural parameters and initial vibration response data of the transmission tower and generate a calibrated finite element model of the tower. The flexible array excitation module is used to plan and deploy a flexible exciter array on the surface of the transmission tower based on the finite element model of the tower, and complete the configuration of the exciter array. The flexible exciter array includes multiple exciter units fixed by permanent magnets, and each exciter unit is provided with a tunable resonant coupling layer at the bottom. An excitation parameter generation module is used to acquire test requirements to determine the target vibration mode, and based on the tower finite element model and the target vibration mode, set hybrid excitation parameters to generate an excitation parameter set. The target vibration mode is a specific vibration pattern reflecting the dynamic characteristics of the transmission tower. The hybrid excitation parameters include resonant coupling layer tuning parameters for low-frequency vibration and exciter drive parameters for high-frequency vibration. Setting the hybrid excitation parameters and generating the excitation parameter set includes: calculating and setting the resonant frequency of the tunable resonant coupling layer for the low-frequency component of the target vibration mode to generate resonant coupling parameters; setting the drive frequency, amplitude, and phase of the exciter unit for the high-frequency source that provides excitation energy for the low-frequency resonance of the target vibration mode to generate exciter drive parameters; and combining the resonant coupling parameters and the exciter drive parameters to form the excitation parameter set. The modal decoupling cooperative control module is used to execute target modal decoupling cooperative control according to the excitation parameter set. It calculates the independent drive signal of each exciter unit through the modal control algorithm, so that the exciter units can cooperatively excite the target vibration mode and generate a cooperative drive signal. The target modal decoupling cooperative control is to eliminate the vibration coupling effect between the exciter units. The dynamic response monitoring module is used to excite the transmission tower based on the cooperative drive signal and monitor the dynamic response data in real time. At the same time, it compares the dynamic response data with the expected response of the target vibration mode to generate response deviation data. The closed-loop feedback adjustment module is used to dynamically adjust the excitation parameter set based on the response deviation data to achieve closed-loop control; The structural damage assessment module is used to extract damage identification features based on the dynamic response data and assess the structural safety of the transmission tower, wherein the damage identification features are modal parameters used to assess structural integrity.

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