High-precision aiming method of laser foreign matter removing device

Abstract

The invention discloses a high-precision aiming method of a laser foreign matter removal device, which belongs to the technical field of laser removal and comprises the following steps of: aiming at a foreign matter shaking characteristic caused by vibration of a power transmission line, dividing target motion into two conditions through a Welch power spectrum estimation algorithm shaking amplitude; predicting the miss distance of the next sampling point of the target through a Kalman filtering algorithm; generating a high-frequency interpolation point between the current sampling point and the prediction point through a cubic spline interpolation algorithm; for small-amplitude high-frequency shaking, the fine tracking system independently controls the fast reflecting mirror to perform fine adjustment; for large-amplitude low-frequency shaking, a coarse tracking system controls a motor to capture a target firstly, and a fine tracking system carries out residual compensation. According to the method, the target aiming precision of the laser foreign matter device under the condition that the foreign matter shakes is improved, and the laser foreign matter removing efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of laser cleaning, and particularly to a high-precision aiming method for a laser foreign object cleaning device. Background Art

[0002] During the operation of transmission lines, they are often faced with various natural and human factors. Among them, hanging foreign objects (such as kite strings, plastic films, balloons, tree branches, etc.) are one of the common potential hazards. These foreign objects may cause line short circuits, tripping, equipment damage, and even large-scale power outages, seriously affecting the stable operation of the power system and power supply reliability.

[0003] Currently, the removal of foreign objects on transmission lines mainly relies on manual inspections, tower climbing operations, tools such as insulating rods, hanging baskets, tow ropes, and the assistance of unmanned aerial vehicles (UAVs). However, tower climbing operations by humans are risky and require power outages. Tools such as insulating rods are complex to operate and have low efficiency. UAVs have limited load capacity and poor stability. In contrast, the laser foreign object remote cleaning technology has significant advantages: it can accurately ablate foreign objects, improve the obstacle removal efficiency; it does not require manual tower climbing, reducing safety risks; automated operations reduce labor input; and it can adapt to complex environments.

[0004] Due to its efficient and safe characteristics, the laser cleaning technology has gradually become the main means for removing foreign objects on transmission lines. However, under windy weather conditions, the cable and the foreign objects wound on it will vibrate and sway, causing the laser aiming system to easily miss the target, seriously affecting the ablation effect. The servo control system of existing laser cleaning equipment has problems such as low tracking accuracy and slow response speed when tracking dynamic targets, and it is difficult to meet the requirements of high-precision aiming. Therefore, there is an urgent need for a technical solution that can effectively cope with cable vibration, foreign object swaying, and improve tracking accuracy and response speed. Summary of the Invention

[0005] Aiming at the problems of easy target miss, low tracking accuracy, and slow response speed of existing laser cleaning equipment under windy weather conditions, the present invention provides a high-precision aiming method for a laser foreign object cleaning device.

[0006] To solve the above technical problems, the technical solution adopted by the present invention is as follows: A high-precision aiming method for a laser foreign object removal device. The laser foreign object removal device includes a laser emitter, a beam controller, a target detection and positioning system, and a compound axis aiming system; the laser emitter is responsible for emitting high-energy laser beams to ablate foreign objects on the transmission line; the beam controller is used to adjust the direction and focus of the laser beam and then emit it through a fast steering mirror to ensure that the laser beam acts precisely on the target; the target detection and positioning system detects the position of the foreign object in real time through a vision sensor and outputs the off-target amount data; the compound axis aiming system realizes the tracking and aiming of a jittering target and consists of a coarse tracking system and a fine tracking system. The coarse tracking system uses a motor as the actuator, and the fine tracking system uses a fast steering mirror as the actuator; the high-precision aiming method includes the following steps:

[0007] Step 1: Input the off-target amount data calculated by the target detection and positioning system.

[0008] Step 2: Perform frequency analysis through the Welch power spectrum estimation algorithm.

[0009] Step 3: Predict the off-target amount of the target at the next sampling point through the Kalman filtering algorithm.

[0010] Step 4: Generate high-frequency interpolation points between the current sampling point and the predicted point through the cubic spline interpolation algorithm to obtain the off-target amount with high-frequency compensation.

[0011] Step 5: According to the frequency analysis result, coordinately control the coarse tracking system and the fine tracking system to complete the aiming task.

[0012] An electronic device includes a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the program, the steps of the above method are implemented.

[0013] A computer-readable storage medium stores a computer program, and when the program is executed by a processor, the steps of the above method are implemented.

[0014] A computer program product includes a computer program, and when the computer program is executed by a processor, the steps of the above method are implemented.

[0015] Compared with the prior art, the significant advantages of the present invention are as follows:

[0016] The present invention proposes a high-precision aiming method suitable for laser foreign object removal tasks. By dividing the target vibration frequency into high-frequency and low-frequency components, dynamic allocation of the coarse and fine control paths is achieved, breaking through the limitations of the response bandwidth of traditional systems.

[0017] The information loss caused by the sampling interval is effectively compensated by Kalman filter prediction and cubic spline interpolation, improving the time resolution and tracking accuracy of the system;

[0018] The proposed high-precision aiming method finally achieves a dynamic aiming accuracy at the micro-radian level, effectively improving the laser ablation efficiency and cleaning success rate. Brief Description of the Drawings

[0019] Figure 1 It is a flowchart of the high-precision aiming method of the present invention.

[0020] Figure 2 It is a graph of the real-time frequency judgment result of the target vibration.

[0021] Figure 3 It is a graph comparing the miss distances before and after the sampling and holding effect compensation.

[0022] Figure 4 It is a graph of the simulation verification results of the high-precision aiming method, where (a) is the tracking error in the high-frequency tracking mode (5 Hz, 0.1 mrad vibration), and (b) is the tracking error in the low-frequency tracking mode (1 Hz, 3 mrad vibration). Detailed Embodiment

[0023] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly described below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0024] The present invention proposes a high-precision aiming method based on a laser foreign object removal device. The overall structure of the laser foreign object removal device includes four core parts: a laser emitter, a beam controller, a target detection and positioning system, and a compound axis aiming system. Among them, the laser emitter is responsible for emitting high-energy laser beams for ablating foreign objects on the power transmission line; the beam controller is used to adjust the direction and focus of the laser beam and then emit it through a fast steering mirror to ensure that the laser beam acts precisely on the target; the target detection and positioning system uses a vision sensor to detect the position of the foreign object in real time and output the miss distance data; the compound axis aiming system realizes the tracking and aiming of the jittering target and is composed of a coarse tracking system and a fine tracking system. The coarse tracking system uses a torque motor with a rotation angle of ±90° and a positioning accuracy of ≤5 mrad as the actuator, which can rotate significantly; the fine tracking system uses a fast steering mirror with a response bandwidth of ≥300 Hz and a resolution of ≤1 urad as the actuator.

[0025] Combined with Figure 1 , the high-precision aiming method of the above laser foreign object removal device includes the following steps:

[0026] Step 1: Input the miss distance data calculated by the target detection and positioning system,

[0027] Step 2: Perform frequency analysis through the Welch power spectrum estimation algorithm;

[0028] Step 3: Predict the miss distance of the target at the next sampling point through the Kalman filtering algorithm;

[0029] Step 4: Generate high-frequency interpolation points between the current sampling point and the predicted point through the cubic spline interpolation algorithm to obtain the miss distance with high-frequency compensation;

[0030] Step 5: According to the frequency analysis results, cooperate to control the coarse tracking system and the fine tracking system to complete the aiming task.

[0031] Furthermore, the specific steps for Step 2 are as follows:

[0032] Step 2.1: Preprocess the input miss distance signal, window the signal using a Hanning window with a 2-second sliding window, and remove the DC component;

[0033] Step 2.2: Perform a fast Fourier transform (FFT) on the preprocessed miss distance signal to calculate the power spectral density;

[0034] Step 2.3: Extract the dominant vibration frequency component of the current miss distance signal by detecting the peak of the power spectrum;

[0035] Step 2.4: Set 3 Hz as the classification threshold according to the analysis of the vibration characteristics of the transmission line and actual engineering experience: when the dominant frequency ≥ 3 Hz, it is determined as high-frequency vibration; when the dominant frequency < 3 Hz, it is determined as low-frequency vibration, as Figure 2 shown.

[0036] Furthermore, for Step 2.1, the matching of the sliding window length and the sampling frequency satisfies: where, T window represents the time length of the sliding window (unit: second); N represents the number of sampling points in each sliding window; f s represents the sampling frequency of the system (unit: Hz).

[0037] Furthermore, for Step 3, based on the motion analysis of the foreign object on the transmission line following the vibration of the cable, a kinematic model of the foreign object on the wire is established, and its motion equation can be expressed as The state transition matrix is calculated through the matrix exponential function F = e AΔt ; where, x represents the miss displacement of the foreign object in the target direction; ω represents the vibration angular frequency, unit is rad / s; A is the state matrix of the system; Δt represents the sampling period of the system, unit is second; F is the state transition matrix.

[0038]

[0039] Further, for step four, according to the determination result of the target vibration frequency, for low-frequency vibration, the interpolation factor is set to 3; for high-frequency vibration, the interpolation factor is set to 10.

[0040] For the setting of the interpolation factor, it is specifically based on the dynamic response capabilities of the coarse and fine tracking systems.

[0041] As Figure 3 shown, through spline interpolation, higher-frequency interpolation points generated between filter updates make the predicted miss distance more delicate and smooth, reducing the average difference between the miss distance at the interpolation points and the true trajectory.

[0042] Further, the cooperative control strategy for step five is as follows:

[0043] High-frequency tracking mode: When the dominant frequency ≥ 3 Hz, it is independently closed-loop controlled by the fine tracking system;

[0044] Low-frequency tracking mode: When the dominant frequency < 3 Hz, the following cooperative process is executed:

[0045] The coarse tracking system intervenes first to stabilize the target within the fine tracking field of view;

[0046] The fine tracking system is synchronously activated for error fine-tuning.

[0047] As Figure 4 shown, through the cooperative control strategy of the compound axis, the tracking accuracy of micro-radians for the jittering target is achieved.

[0048] The above embodiments are only examples of the specific implementation manners of the present invention, which are used to help understand the technical solutions and core ideas of the present invention, and are not intended to limit the protection scope. Based on the technical principles disclosed in the present invention, all technical solutions obtained by those skilled in the art without creative efforts by adjusting parameters, replacing equivalent components, or changing the specific implementation process shall be regarded as falling within the protection scope of the claims of the present invention.

[0049] Although the present invention has been described in detail through the drawings and embodiments, those skilled in the art should understand that without departing from the spirit of the technical solutions of the present invention, the technical solutions formed by equivalent replacement, combined deformation, or adaptive adjustment of the technical features in the embodiments all fall within the protection scope defined by the claims of this patent.

Claims

1. A high-precision aiming method for a laser foreign object removal device, characterized in that, The laser foreign object removal device includes a laser emitter, a beam controller, a target detection and positioning system, and a compound axis aiming system; the laser emitter is responsible for emitting a high-energy laser beam to ablate foreign objects on the transmission line; the beam controller is used to adjust the direction and focus of the laser beam and emit it through a fast steering mirror to ensure that the laser beam acts precisely on the target; the target detection and positioning system detects the position of the foreign object in real time through a vision sensor and outputs the off-target amount data; the compound axis aiming system realizes the tracking and aiming of a jittering target and consists of a coarse tracking system and a fine tracking system. The coarse tracking system uses a motor as an actuator, and the fine tracking system uses a fast steering mirror as an actuator; The method includes the following steps: Step 1: Input the off-target amount data calculated by the target detection and positioning system; Step 2: Perform frequency analysis through the Welch power spectrum estimation algorithm; Step 3: Predict the off-target amount of the target at the next sampling point through the Kalman filtering algorithm; Step 4: Generate high-frequency interpolation points between the current sampling point and the predicted point through the cubic spline interpolation algorithm to obtain the off-target amount with high-frequency compensation; Step 5: According to the frequency analysis result, coordinately control the coarse tracking system and the fine tracking system to complete the aiming task.

2. The high-precision aiming method of the laser foreign object removal device according to claim 1, characterized in that, The specific implementation method of the said Step 2 is: Step 2.1: Preprocess the input off-target amount signal, window the signal with a Hanning window with a 2-second sliding window, and remove the DC component; Step 2.2: Perform a fast Fourier transform on the preprocessed off-target amount signal to calculate the power spectral density; Step 2.3: Extract the dominant vibration frequency component of the current off-target amount signal by detecting the peak of the power spectrum; Step 2.4: Set 3Hz as the classification threshold according to the analysis of the vibration characteristics of the transmission line and actual engineering experience: When the dominant frequency ≥ 3Hz, it is determined as high-frequency vibration; When the dominant frequency < 3Hz, it is determined as low-frequency vibration.

3. The high-precision aiming method of the laser foreign object removal device according to claim 2, characterized in that In step 2.1, the sliding window length and the sampling frequency satisfy: where T window represents the time length of the sliding window, N represents the number of sampling points in each sliding window, and f s represents the sampling frequency of the system.

4. The high-precision aiming method of the laser foreign object removal device according to claim 1, characterized in that, In the third step, according to the motion analysis of the foreign object on the transmission line following the vibration of the cable, a kinematic model of the foreign object on the conductor is established, and its motion equation is expressed as The state transition matrix is calculated through the matrix exponential function \(F = e^{}\) AΔt , where \(x\) represents the miss distance of the foreign object in the target direction; \(\omega\) represents the angular frequency of vibration, \(A\) is the state matrix of the system, \(\Delta t\) represents the sampling period of the system, and \(F\) is the state transition matrix.

5. The high-precision aiming method of the laser foreign object removal device according to claim 1, characterized in that In the said Step 4, according to the determination result of the target vibration frequency, for low-frequency vibration, the interpolation factor is set to 3; for high-frequency vibration, the interpolation factor is set to 10.

6. The high-precision aiming method of the laser foreign object removal device according to claim 1, characterized in that, The coordinated control strategy in the said Step 5 is: High-frequency tracking mode: When the dominant frequency ≥ 3Hz, it is independently closed-loop controlled by the fine tracking system; Low-frequency tracking mode: When the dominant frequency < 3Hz, perform the following process: The coarse tracking system intervenes first to stabilize the target within the field of view of the fine tracking; The fine tracking system is synchronously activated for error fine-tuning.

7. An electronic device, comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that, When the processor executes the said program, it realizes the steps of the method as described in any one of claims 1-6.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the said program is executed by the processor, it realizes the steps of the method as described in any one of claims 1-6.

9. A computer program product, comprising a computer program, characterized in that, When the said computer program is executed by the processor, it realizes the steps of the method as described in any one of claims 1-6.

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