Method for visualizing and marking a face of a tunnel based on a photosensitive material and a laser mapping

Abstract

The application discloses a method for visualizing and marking a working face blast hole based on a photosensitive material and laser mapping, relates to the technical field of auxiliary positioning for underground engineering construction, and comprises the following steps: in a blasting construction environment, collecting real-time changes of current signals, voltage signals and control instruction signals of a laser control system, constructing an electromagnetic pulse interference dynamic monitoring model, extracting time-frequency characteristics of electromagnetic disturbance, and generating an interference intensity distribution map for identifying electromagnetic interference sources and their distribution. The method realizes real-time identification of electromagnetic interference intensity and sources, combines laser trajectory offset analysis and stability evaluation, dynamically adjusts scanning parameters to match the characteristics of the photosensitive material, and constructs a closed-loop optimization mechanism through development quality and positioning error feedback, so as to guarantee marking accuracy and operation safety.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of auxiliary positioning for underground engineering construction, and particularly relates to a method for visualizing marking of a tunnel face blasthole based on photosensitive material and laser mapping. BACKGROUND

[0002] The "visualized marking of a tunnel face blasthole based on photosensitive material and laser mapping" refers to a technical means for marking the position of a designed blasthole (a drill hole for charging and blasting) on a tunnel or mine tunnel face (i.e. the rock surface of the front of the excavation operation) in a high-precision and visualized manner by using photosensitive material capable of responding to specific light and combining with a controllable laser projection system. The basic principle is: a photosensitive coating is uniformly covered on the surface of the tunnel face rock mass, and the laser mapping system converts the coordinates of the blasthole position into a laser trajectory according to the blasting design drawing, and scans point by point on the photosensitive surface, and triggers the change of color, reflectivity or fluorescence characteristics of the photosensitive material through laser irradiation, thereby forming a clear and visible blasthole marking pattern on the rock surface. Compared with the traditional manual line drawing or template positioning method, the method can significantly improve the accuracy, construction efficiency and night operability of blasthole layout, and is particularly suitable for underground engineering construction scenes in low light environments.

[0003] The prior art has the following disadvantages:

[0004] In the continuous blasting construction environment of a tunnel or mine, frequent high-intensity blasting operations on site release a large amount of transient high-energy shock waves and electromagnetic radiation signals, forming a strong high-energy electromagnetic pulse interference field. Since the control mainboard and servo positioning components in the existing laser marking system are usually deployed in the front end operation area of the tunnel face, their anti-interference ability is limited, and they lack shielding and filtering design for high-energy electromagnetic environment, so they are easily affected by the pulse interference generated during the blasting process, resulting in abnormal behaviors such as non-planned jumping, angle deviation or transient trajectory drift of the laser when executing the projection instruction. The abnormal laser path triggered by the interference will form multiple overlapping, blurred or position deviated marking tracks on the photosensitive material surface, which will be manifested as non-design "ghost" marks. Such pseudo marks do not have engineering effectiveness, but their visual features are often difficult to distinguish from real marks, which can easily mislead construction personnel to make wrong drilling and blasthole layout operations, and then cause serious mispositioning of blasting points, resulting in damage to the structure of the tunnel face, decrease in rock mass stability and even induce major safety accidents.

[0005] The above information disclosed in the background section is only used to strengthen the understanding of the background of the present disclosure, and therefore it can include information that does not constitute prior art known to those of ordinary skill in the art. SUMMARY

[0006] The invention aims to provide a face of working face borehole visualization marking method based on photosensitive material and laser mapping to solve the problems in the background art.

[0007] To achieve the above-mentioned purpose, the invention provides the following technical solution: a face of working face borehole visualization marking method based on photosensitive material and laser mapping, comprising the following steps:

[0008] S1, in the blasting construction environment, the real-time changes of the current signal, voltage signal and control instruction signal of the laser control system are collected, an electromagnetic pulse interference dynamic monitoring model is constructed, the time-frequency characteristics of electromagnetic disturbance are extracted, and an interference intensity distribution map is generated for identifying the electromagnetic interference source and its distribution;

[0009] S2, based on the interference intensity distribution map, the instruction offset trajectory of the laser control system is extracted, the jump amplitude and duration are calculated, and the interference risk level is output for evaluating the stable state of the control system;

[0010] S3, according to the interference risk level, the laser projection path is reconstructed in real time, by comparing the historical trajectory with the current trajectory, the direction and position offset of the laser beam are corrected, and the projection trajectory is aligned with the preset coordinates;

[0011] S4, on the basis of trajectory reconstruction, path stability evaluation is performed, trajectory consistency analysis is performed between frames, and trajectory credibility index is output to verify the reconstruction effect;

[0012] S5, based on the trajectory credibility index, the laser scanning speed and power density parameters are dynamically adjusted to realize the matching of the laser output characteristics and the photosensitive material response characteristics, and the marking clarity and positioning accuracy are improved;

[0013] S6, the developing quality and positioning error of the laser marking pattern are input as feedback information into the interference dynamic monitoring model, the interference identification parameters and control compensation strategy are updated in real time, and a closed-loop mechanism of analysis, identification and regulation is constructed.

[0014] Preferably, step S1 comprises:

[0015] The three-channel acquisition device is connected to the direct current power supply loop, the servo driver output loop and the laser scanning instruction signal path of the laser control device respectively, the sampling accuracy is higher than 16 bits, and the sampling frequency is 20kHz;

[0016] After collecting the change data of the current signal, voltage signal and control instruction signal, fast Fourier transform, short-time Fourier transform and wavelet packet decomposition are performed respectively to extract the maximum spectral amplitude, main frequency shift rate, pulse peak energy and duration characteristics;

[0017] According to the time-frequency characteristics of the three types of signals, a two-dimensional interference intensity distribution map is constructed, in which the horizontal axis is the signal path sequence, the vertical axis is the blasting time window, and the color coding represents the interference energy density.

[0018] According to the interference amplitude and duration of each path in the map, a risk value is calculated and an interference level is divided, which is used for subsequent laser trajectory correction and operation window scheduling control.

[0019] Preferably, step S2 comprises:

[0020] Based on the interference intensity distribution map, a control instruction trajectory is extracted, and the spatial offset and jump speed of each trajectory point are calculated;

[0021] The central difference method is used to extract the trajectory speed change rate, and the signal noise is removed by three-order median filtering to extract the real trajectory jump behavior;

[0022] A comprehensive index function of anti-interference performance is constructed, which integrates the offset amplitude, jump rate and continuous abnormal duration according to the weight, and outputs the anti-interference risk coefficient;

[0023] According to the anti-interference risk coefficient, the risk level is divided, higher than 0.75 to stop the task, between 0.45 and 0.75 to execute trajectory reconstruction, and lower than 0.45 to maintain the current task and continue to monitor.

[0024] Preferably, the specific steps of constructing the comprehensive index function of anti-interference performance are as follows:

[0025] The spatial offset amplitude of each control point in the laser control instruction trajectory is extracted, and the maximum instantaneous offset value is calculated as the offset amplitude reference index;

[0026] The velocity change rate of the trajectory point is processed by the central difference method, and the maximum angular velocity change rate is extracted as the jump rate reference index;

[0027] The time length of the continuous abnormal section in the trajectory is detected, and the jump duration is calculated as the time dimension index;

[0028] The offset amplitude, jump rate and duration are respectively assigned weights of 0.5, 0.3 and 0.2, and a normalized anti-interference risk coefficient is constructed by linear weighting, which is used as the basis for evaluating the stability level of the control system.

[0029] Preferably, step S3 comprises:

[0030] Determine whether the interference risk level is greater than or equal to 0.45, if it is satisfied, the historical projection trajectory recorded in the same working surface area in the last blasting cycle is called as the standard trajectory;

[0031] Collecting current laser scanning trajectory data and comparing with historical trajectory point by point according to time number, extracting lateral and longitudinal offset values of each point and generating trajectory error distribution table;

[0032] Using weighted least squares method to fit the offset points, constructing correction vector according to offset amplitude and geometric structure importance and replacing the coordinate and angle parameters in the original control instruction;

[0033] The corrected trajectory is virtually marked in a reduced power mode, and whether the pattern satisfies the offset of not more than ±2mm is judged according to the image collected by the image sensor. If it is satisfied, the formal marking is executed.

[0034] Preferably, step S4 comprises:

[0035] Using a high-frame-rate image acquisition device to record the projection process of the laser beam on the photosensitive material surface at a frequency of more than 60 frames per second, and obtaining a sequence of spatial trajectory images within a continuous time frame;

[0036] Performing edge extraction and vectorization processing on the image sequence to obtain a set of spatial coordinate points of the laser trajectory in each frame, and calculating the spatial displacement and direction change of the trajectory points between adjacent frames;

[0037] Using a sliding time window method to analyze the trajectory offset characteristics between consecutive frames, calculating the path coincidence rate, maximum jump amplitude, direction fluctuation range and curvature change standard deviation;

[0038] After normalizing the obtained parameters, the weighted sum is calculated according to the weight, and the trajectory reliability index is output. If the trajectory reliability index is higher than 0.85, it is determined that the trajectory reconstruction is effective and enters the formal projection process.

[0039] Preferably, step S5 comprises:

[0040] According to the grade to which the trajectory reliability index belongs, the corresponding scanning speed and power density combination parameters are selected;

[0041] Using the control instruction to adjust the motor drive pulse frequency to set the scanning speed, and synchronously adjusting the laser current output value to set the power density;

[0042] Performing pattern projection and collecting developed pattern image through image acquisition device, analyzing edge definition, positioning error and path coincidence rate index;

[0043] Judging whether the developed index meets the set standard. If it is satisfied, it enters the formal marking process. If it is not satisfied, the corrected trajectory reliability index and parameter mapping relationship are fed back and the parameters are fine-tuned.

[0044] Preferably, step S6 comprises:

[0045] Collect image data and extract pattern boundary, corner point coordinate and gray scale distribution information, obtain developing quality index and positioning error index;

[0046] The developing quality index and the positioning error index are normalized and combined into a composite feedback variable;

[0047] The electromagnetic interference identification sensitivity threshold, the track jump identification tolerance and the control compensation strategy parameters are updated according to the composite feedback variable;

[0048] The updated control parameters are applied to the next round of laser marking task and closed loop execution is performed, and the interference space distribution estimation graph is periodically reconstructed to improve the subsequent identification accuracy.

[0049] In the above technical solution, the technical effects and advantages provided by the present application are as follows:

[0050] The present application can accurately identify and quantify the intensity and source of electromagnetic pulse interference in the blasting construction environment, and can also guide the high-precision reconstruction of the subsequent projection trajectory through real-time extraction and risk assessment of the laser control instruction offset trajectory. Further combined with trajectory stability analysis and credibility index output, the scanning speed and power density are dynamically adjusted to make the laser output behavior and the developing reaction characteristics of photosensitive materials form the best match, so that clear and accurate marking patterns can still be obtained under complex interference background. Finally, by taking the actual developing quality and position error of the marking pattern as a feedback variable, the interference monitoring model is introduced for parameter self-learning and identification strategy iteration, forming an intelligent closed loop of "identification - correction - verification - optimization", effectively avoiding the drilling misjudgment and blasting accidents caused by "ghost" marking, and greatly improving the automation degree, safety and construction efficiency of the working face eyelet operation. BRIEF DESCRIPTION OF DRAWINGS

[0051] In order to more clearly illustrate the technical solutions in the embodiments or prior art, the drawings needed in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments described in the present application, and other drawings can also be obtained by those skilled in the art based on these drawings.

[0052] Figure 1 The method flowchart of the present application based on photosensitive material and laser mapping working face visualized marking method. DETAILED DESCRIPTION

[0053] Example implementations will now be described more fully with reference to the accompanying drawings. Example implementations may, however, be implemented in many different forms and should not be construed as limited to the examples set forth herein; rather, these example implementations are provided so that this disclosure will be thorough and complete, and will fully convey the inventive aspects to those skilled in the art. Like reference numerals may refer to like elements throughout.

[0054] The application provides a method for visualizing a working face borehole based on a photosensitive material and laser mapping, as shown in the specification. Figure 1 The method comprises the following steps:

[0055] S1, in the blasting construction environment, a dynamic monitoring model of electromagnetic pulse interference is constructed, the real-time change trend of the current signal, voltage signal and control instruction signal inside the laser control system is collected, the time-frequency characteristics of electromagnetic disturbance at the blasting moment are extracted, and an interference intensity distribution map is generated to identify the position of the electromagnetic interference source and the interference intensity distribution.

[0056] In order to deal with the problem of frequent high-intensity electromagnetic interference in the blasting construction environment and ensure the stability and precision of laser marking, a dynamic monitoring mechanism for analyzing and identifying the blasting electromagnetic disturbance behavior is constructed. The real-time characteristic change of current, voltage and control instruction signal is taken as the core detection object, relying on the steps of continuous data collection, interference extraction, atlas modeling and risk quantification, the positioning identification of the electromagnetic interference source at the blasting moment and the quantitative evaluation of the disturbance intensity are realized, and accurate interference criteria are provided for laser trajectory reconstruction and subsequent closed-loop control.

[0057] In practical application, a set of three-channel high-speed acquisition devices are used to access three key parts of the laser control device: one is the direct current power supply loop of the power input end, which is used to detect the voltage surge behavior caused by electromagnetic pulse; the second is the current output loop connected with the servo driver, which is used to capture the abnormal change of load current caused by electromagnetic interference; the third is the laser scanning instruction signal path sent by the main control board, which is used to identify the change mode of pulse misplacement, amplitude jump or period drift of logic control instruction under electromagnetic interference. The three-channel acquisition devices all use analog-to-digital conversion chips with sampling accuracy higher than 16 bits, and the sampling frequency is set to 20 kHz, which ensures the synchronous capture of high-frequency disturbance components caused by blasting within microseconds, and cooperates with independent clock source to realize sampling time alignment, improving the integrity and comparability of interference data.

[0058] After obtaining the above three types of original signal data, they are immediately input into the data analysis process for joint signal processing, and the fast Fourier transform (FFT) is used to perform spectrum reconstruction on each type of signal to identify the energy aggregation characteristics in the specific frequency band excited during blasting. At the same time, the short-time Fourier transform (STFT) is used to extract the instantaneous frequency change of the signal in different time windows, and the secondary wavelet packet transform is used to decompose the high-frequency pulse sequence embedded in the signal to reveal the disturbance trend hidden behind voltage jitter, current surge and control signal instability. In this process, the maximum spectral amplitude, main frequency migration rate, pulse peak energy and duration index contained in each acquisition path are calculated respectively to form a set of time-frequency characteristic parameters for subsequent interference atlas generation.

[0059] Based on the above multi-source signal processing results, the interference strength is matrixed according to the time dimension and the path dimension to generate a two-dimensional interference strength distribution map. The horizontal axis of the map represents three signal paths (i.e. power supply path, driving path and command path), the vertical axis represents the blasting period divided in milliseconds, and the matrix unit value is the interference strength on the corresponding period and path, which is based on the comprehensive energy density calculated by the aforementioned characteristic parameters. The interference strength matrix is visualized using color coding, and the thermal color scale from dark blue to red is used to express the interference energy level trend, thereby generating a high-resolution interference thermal map that can intuitively reflect the electromagnetic disturbance diffusion path, intensity distribution and spectral concentration area, assisting analysts in identifying the disturbance starting point, impact path and scope.

[0060] After the interference thermal map is constructed, the maximum and average values of the interference indicators of each path before and after blasting are extracted based on the map data, the interference amplitude of each path is normalized, and the interference risk value is calculated based on the frequency and duration of the interference. Taking the risk value as the core indicator, set multiple interference level thresholds, for example, interference value exceeding 0.8 is high risk, 0.5 to 0.8 is medium risk, and less than 0.5 is low risk, and this risk level is used as the criterion for control strategy switching and obstacle avoidance warning. The risk level result not only inputs into the subsequent trajectory correction and control adjustment process, but also can be used by the on-site operation scheduling personnel to set the time window for laser marking operation, avoiding the interference peak interval to execute critical instructions, thereby improving the success rate and accuracy of marking.

[0061] The role of this step is to provide a high-time-efficiency and high-precision interference perception mechanism for the laser marking system of the working face, to solve the problems of unpredictable, instantaneous burst and complex propagation path of electromagnetic interference in the blasting construction environment. In tunnel or mine operations, blasting behavior can produce a large number of high-energy shock waves and strong electromagnetic pulse signals, which can easily couple into the laser control system through wire, power supply or space induction, interfere with its control instructions, power supply and driving signals, and then cause the laser to jump, misfire or mark path drift. Traditional laser marking systems lack pre-perception ability and real-time response mechanism for such electromagnetic interference, resulting in frequent false marking or trajectory ghosting, which seriously affects the accuracy of hole layout and construction safety.

[0062] The step extracts the typical characteristic parameters of the blasting interference in time domain and frequency domain by synchronously collecting the transient changes of the current, voltage and control instruction signals of the key circuit nodes of the laser control system, and constructs a quantifiable and visualized interference intensity distribution diagram for identifying the propagation path, starting position and influence intensity of the interference source. This processing not only provides necessary basis for subsequent trajectory correction and control compensation, but also is a prerequisite for realizing system closed-loop control, adaptive adjustment and precise projection. Therefore, the implementation of this step is the core of establishing the anti-interference ability of the entire visualized marking system, is a key link for guaranteeing the precision of laser projection and the effectiveness of marking, and plays a decisive role in improving the robustness and stability of the system.

[0063] S2, based on the interference intensity distribution diagram, extracting the control instruction offset trajectory of the laser control system under the action of electromagnetic interference, calculating the trajectory jump amplitude and jump duration, and outputting the interference risk level reflecting the anti-interference performance of the control system, for evaluating the stable state of the current laser control system;

[0064] To ensure the operation stability of the laser control device in a complex blasting environment and realize dynamic evaluation of its anti-interference performance, it is necessary to further analyze the control instruction response trajectory based on the electromagnetic interference intensity distribution diagram, quantify the trajectory offset behavior under the influence of interference, and finally output the interference risk level. This process includes the following steps in sequence: instruction trajectory extraction, trajectory offset calculation, jump behavior quantification and anti-interference level output, forming a complete control stability evaluation path.

[0065] In the generated electromagnetic interference intensity distribution diagram, the time interval in which the interference peak value appears is identified, and a time period of 1.5 seconds before and after this interval is taken as an analysis window, and all projection control instructions in this time period are continuously extracted from the laser control device. The extracted instruction content includes the set value of the laser scanning direction angle, the spatial coordinates of the scanning starting point and ending point, the angular velocity adjustment instruction and the light beam activation state instruction. Each instruction is attached with a nanosecond-level time stamp to ensure its accurate alignment on the time axis. On this basis, the laser scanning path is reconstructed according to the instruction trigger sequence, and the complete control instruction trajectory is represented in two-dimensional coordinate form. This trajectory is used for subsequent error calculation with the design reference trajectory, and must be strictly mapped through coordinate synchronization comparison to ensure one-to-one correspondence of the points, without missing or overlapping points.

[0066] The actual control instruction trajectory extracted above is compared with the preset design trajectory point by point, and the spatial offset of each scanning control point is calculated. Specifically, it includes the lateral offset distance in the X direction, the longitudinal offset distance in the Y direction, and the comprehensive offset amplitude in the two-dimensional plane. Further combined with the time interval of the continuous control points, the speed change rate of the trajectory jump, the trajectory curvature change slope and the angle difference between adjacent control points during the execution of the laser beam are calculated. These calculations use the central difference method to numerically derive the coordinate changes to obtain the time evolution characteristics of the jump trend. At the same time, in order to avoid false jump responses caused by signal jitter, a third-order median filter is used to filter the trajectory data, retain the sudden jump points, and eliminate random noise points, so as to ensure that the results truly reflect the physical trajectory abnormalities caused by electromagnetic disturbance.

[0067] The central difference method is a method of approximating the derivative at a certain time by taking the difference between the two adjacent points before and after that time. It assumes that the function changes in a symmetrical manner near that point, so it uses symmetric differences to avoid the bias caused by forward or backward differences. When used to analyze the laser control instruction trajectory, its role is to identify the change trend of the trajectory points in the time sequence. By differentiating the position before and after each trajectory point by the time interval, the instantaneous speed vector at that point can be obtained, reflecting the dynamic change degree of the laser scanning motion at that time. Further, the speed vector change of the continuous time points is differentiated, and the speed change rate can be extracted to reveal whether the trajectory has a sudden change. This method can accurately capture the non-continuous response behavior caused by electromagnetic interference, and by quantifying the amplitude and occurrence time of the jump, it realizes the logical judgment of the stability of the trajectory and the response ability of the control system.

[0068] According to the data of the above three dimensions of offset amplitude, jump rate and interference duration, a comprehensive index function of anti-interference performance is constructed. The function is constructed by linear weighted summation, with the offset amplitude accounting for 0.5 of the weight, the jump rate accounting for 0.3 of the weight, and the trajectory duration accounting for 0.2 of the weight. The sum of the three is normalized to an anti-interference risk coefficient between 0 and 1. The value of the offset amplitude is derived from the maximum instantaneous spatial offset value, the jump rate is extracted according to the maximum change rate of the angular velocity, and the duration is based on the time accumulation of the continuous abnormal segment. The final output anti-interference risk coefficient can comprehensively reflect the stability level of the current laser control device under electromagnetic disturbance, and is the key basis for judging whether to start the subsequent trajectory correction mechanism or control strategy switching.

[0069] The anti-interference performance comprehensive index function is a function logic structure for quantitatively evaluating the running stability of the laser control device under the action of electromagnetic interference. Its core function is to integrate and normalize the scattered interference effect characteristics such as offset amplitude, jump rate and interference duration through unified rules to output a single evaluation result reflecting the overall anti-interference ability in the presence of multiple interference influence dimensions. The result is usually used to determine whether the current system is in a safe and controllable state, whether it needs to start deviation correction, correction or interrupt operation. The function is not fixed to a certain form, and can draw lessons from fuzzy logic function, linear weighted function, maximum and minimum reduction method or expert scoring-based empirical model, the key is to establish clear weight and threshold rules, so that different dimensional interference factors can logically explain the system stability level. In this method, the introduction of the function realizes the transformation from qualitative perception to quantitative judgment, which is the logical premise and core basis for subsequent control decision, grade classification and safety linkage response.

[0070] According to the anti-interference risk coefficient, the interference risk grading standard is set, and the system running state is divided into three levels: when the risk coefficient is greater than or equal to 0.75, it is determined as high risk level, the laser marking task is immediately suspended, the system enters the protection mode, and the fault report is generated for manual analysis; when the risk coefficient is between 0.45 and 0.75, it is determined as medium risk level, the system switches to the trajectory reconstruction process, the real-time path correction algorithm is enabled, and the stability warning information is displayed on the operation interface; when the risk coefficient is less than 0.45, it is determined as low risk level, the system maintains the current marking task and continuously monitors the interference state change.

[0071] The real-time path correction algorithm refers to an algorithm method that continuously and dynamically calculates and immediately adjusts the control instruction based on the deviation between the current trajectory and the target trajectory during laser projection, to ensure that the laser beam always runs accurately according to the preset path. In this invention, the function of this algorithm is to immediately identify the position and direction of trajectory deviation after the laser control device is interfered by electromagnetic interference, and to accurately compensate the laser emission angle, position coordinate or scanning sequence by generating a correction amount in real time, so as to avoid the pattern distortion, marking position deviation or ghosting phenomenon on the photosensitive material caused by path drift, and ensure that the final marking pattern is highly consistent with the design drawing.

[0072] The algorithm can be based on the existing dynamic time warping algorithm, Kalman filter or sliding window least square fitting algorithm. For example, the Kalman filter can fuse the error between the current trajectory point and the predicted trajectory point, continuously update the estimated state in the sampling period, realize smooth correction, and is suitable for trajectory registration in non-uniform scanning state. In general, the real-time path correction algorithm is the key supporting technology of the application to ensure the accuracy of laser projection trajectory and stable operation of the system.

[0073] The purpose of this step is to further push the influence of electromagnetic interference from the perception level to the behavior analysis and system state evaluation level, aiming to accurately identify the abnormal control behavior of the laser control device under the action of blasting interference, and to systematically judge the running stability through quantitative indicators. In the actual blasting environment, electromagnetic pulses not only affect the power supply and signal path inside the laser device, but also cause the control command to jump, delay or distort at the logic control level, which leads to the deviation of the laser beam from the designed trajectory and forms a false mark. Only by the interference intensity distribution map can the interference source and its spatial diffusion characteristics be identified, but it is difficult to directly judge the specific influence degree of the interference on the system behavior. Therefore, this step compares the execution trajectory of the control command under the interference condition with the preset designed trajectory, identifies the specific time, direction and amplitude of the deviation, and further calculates the duration and change rate of the jump, thereby establishing a dynamic behavior-oriented interference response quantification mechanism. On this basis, by constructing an anti-interference performance comprehensive index function, multiple interference performance dimensions are summarized, and a unified interference risk level is output to represent the current stable state of the control system. The level can not only be used to judge whether to trigger the trajectory reconstruction and parameter adjustment process, but also can guide the operation personnel to take peak avoidance operation or interruption operation strategy when the risk level is high, which is the key link to realize the safe operation and intelligent response of the laser marking system.

[0074] S3, according to the interference risk level, real-time trajectory reconstruction of the laser projection path is performed, by comparing and analyzing the historical laser projection trajectory and the current disturbed laser trajectory, the direction deviation and position drift error of the laser beam are corrected, and it is ensured that the projection trajectory of the laser beam on the photosensitive material surface is consistent with the preset designed coordinate;

[0075] To ensure the accuracy of laser projection in the presence of blasting electromagnetic interference, the actual scanning path of the laser beam must be reconstructed in real time based on the identified interference risk level, so as to compensate for the directional deviation and spatial drift error caused by control command disturbance, and ensure that the final projection pattern formed on the photosensitive material surface is completely consistent with the design drawing coordinates. The trajectory reconstruction process includes the steps of historical trajectory calling, current trajectory difference extraction, offset error calculation and path reconstruction verification.

[0076] After the interference risk level is output, it is determined whether the trajectory reconstruction condition is met. If the interference risk level is greater than or equal to the set threshold value 0.45, the trajectory reconstruction process is started immediately. After the process is started, the complete historical trajectory data recorded in the same working face area, the same blasting sequence number and the laser equipment number in the last blasting cycle is called from the non-volatile memory of the laser control device. The historical trajectory data is stored in the form of two-dimensional point set, including the X-axis coordinate, Y-axis coordinate, scanning sequence number, corresponding scanning angle (unit: degree) and laser power level (unit: milliwatt) of each projection point. All data has been synchronized calibrated according to the absolute timestamp, and the coordinates have been precision calibrated in millimeters. The historical trajectory enters the subsequent comparison calculation stage as the "standard trajectory".

[0077] The trajectory reconstruction process refers to a series of targeted data processing and control command updating operations performed after the laser control device is affected by blasting electromagnetic interference, in order to restore the normal projection path of the laser beam and eliminate trajectory jump and drift error. Its main function is to use the difference information between historical stable projection data and current abnormal trajectory to optimize the original control command in real time through calculation of correction vector when it is detected that the current laser scanning trajectory deviates from the design trajectory, and generate a new trajectory consistent with the design coordinates, so as to ensure that the pattern formed on the photosensitive material surface has geometric accuracy and spatial consistency. The specific process includes the following steps:

[0078] Extract the historical stable projection trajectory matching the current construction position and time node as the reference path, and ensure the alignment of the data on the time axis and the coordinate system;

[0079] Collect the current laser actual scanning path, compare the current trajectory with the historical trajectory point by point through time number, and identify the offset points and drift areas;

[0080] Based on the comparison result, a correction vector is constructed, and the control angle and coordinate value are accurately adjusted using a weighted fitting method to generate a corrected projection path;

[0081] The path is sent to the control device to perform a preliminary low-power scan, and the correction result is verified by image recognition comparison to determine whether it meets the preset accuracy requirements. If it does, the formal marking process is started, otherwise the parameter is iteratively fine-tuned. The trajectory reconstruction process plays a key role in the entire laser marking system, compensating and self-recovering, and is the key mechanism to ensure that the system still has high-precision projection capabilities in a strong interference environment.

[0082] Real-time acquisition of actual scanning trajectory data of the laser beam under the current disturbed state. The data comes from three sources: first, a high-resolution angle encoder installed on the galvanometer shaft, used to obtain scanning angle feedback; second, the actual drive instruction record output by the control device, used to capture target coordinates; third, the boundary contour points of the displayed pattern on the projection surface obtained by the image acquisition device, as a verification reference. By matching the current trajectory data with the historical trajectory in chronological order, the spatial offset value in the horizontal (X direction) and vertical (Y direction) is calculated at each scanning point, with an accuracy of 0.1 mm. At the same time, the time position and offset direction of each offset point are recorded to form a trajectory error distribution table. The trajectory error data is aggregated by spatial position to identify the continuity, abruptness and trend changes between the offset point groups for subsequent error correction function modeling.

[0083] The difference between the current trajectory and the historical trajectory is taken as input to carry out trajectory reconstruction calculation. Specifically, based on the weighted least squares fitting method, an optimal correction vector is constructed for each offset projection point. The direction of each correction vector is determined by the corresponding historical trajectory point pointing to the current disturbed trajectory point, and the size is calculated based on the offset amplitude and the importance of the point's structural position in the overall trajectory, with priority given to key corner points, edge points and geometric turning points. To avoid local over-correction during trajectory reconstruction, especially in areas with sharp curvature changes, an angle change threshold of plus or minus 3 degrees is set to limit the range of single-point direction adjustment. After fitting, the angle and coordinate values of the correction vector are directly replaced by the projection parameters in the original control instructions to form a set of adjusted new trajectory control data, which is written into the execution buffer to overwrite the original disturbed trajectory for the laser emission device to follow the next path and project the pattern. This process ensures the continuity and geometric accuracy of the trajectory, providing an accurate data basis for subsequent development verification and formal marking.

[0084] The fitting process of the weighted least squares method is a mathematical method used to improve the fitting accuracy when there are errors in the data points with different magnitudes or different levels of reliability. In the trajectory reconstruction process, the fitting process compares the current disturbed laser trajectory with the historical stable trajectory point by point, assigns different calculation weights according to the offset magnitude of each scanning point and the importance of its position, and then constructs an optimal correction path to ensure that the final generated trajectory is highly consistent with the design graph coordinates. The specific fitting process is as follows: First, form a coordinate pair difference between each disturbed trajectory point and its corresponding historical trajectory point, construct an offset vector, and set weights according to the size of the offset magnitude or the structural importance of the point in the overall graph (such as edge points, corner points, path turning points). The larger the weight value, the more critical the point is to correct. Second, input all offset points and their weights into the fitting algorithm to solve the best correction path by minimizing the weighted residual sum of squares, i.e. to make the corrected trajectory points as close as possible to the original design trajectory as a whole. Finally, the fitting result is used to update the angle offset in the control command and the scanning coordinates, thereby outputting a disturbed trajectory path after interference compensation. This method is more flexible and accurate than the ordinary least squares method, especially suitable for scenarios where the scanning path is unstable due to electromagnetic interference, and can significantly improve the geometric reduction degree and positioning accuracy of the reconstructed pattern.

[0085] Apply the reconstructed trajectory instructions to the laser projection process, initially execute a virtual marking process with the power reduced to 60% of the rated value, and collect the developed pattern formed by the front-end image sensor. After edge extraction processing, the image is compared with the reference boundary of the design drawing in terms of coordinates to verify the spatial consistency between the corner points, edge center points, and the marked reference points. If all key points are within ±2mm of the offset, it is determined that the reconstructed path is valid, the laser power is restored to the original set value, and the formal marking process begins; if the offset exceeds the threshold, the error analysis and vector fitting process of the second stage is re-entered, the correction parameters are updated, and the projection verification is performed again.

[0086] The role of this step is to restore the accuracy and stability of the laser beam projection path in time under the influence of electromagnetic interference, ensuring that the pattern finally formed on the photosensitive material surface can strictly correspond to the preset design coordinates, avoiding marking errors caused by trajectory drift or deviation. In the blasting construction environment, the laser control device is easily affected by electromagnetic pulse interference, causing the laser beam to jump in angle or distort the path when performing projection tasks, resulting in position offset or even ghost marking. This deviated trajectory not only destroys the geometric accuracy of the projected pattern, but also seriously misleads subsequent drilling operations based on the marking. Therefore, after the system detects a medium or higher interference risk level, the trajectory reconstruction process must be started immediately to compare the actual scanning path of the current laser beam with the standard trajectory generated under non-interference conditions in the historical record. By analyzing the differences in spatial coordinates of each scanning point, the offset direction, error magnitude and distribution area are identified, and a correction vector is constructed to adjust the projection angle and coordinate parameters in the control command in real time. The new trajectory data generated after reconstruction will replace the original disturbed command and be sent to the laser emission control end to ensure that the laser beam scans according to the corrected path. After performing low-power simulation projection verification, the system further judges whether the projected pattern meets the spatial accuracy requirements through image comparison. If the verification is passed, it enters the formal marking phase. Through the execution of this step, the laser marking process has the ability to self-correct and self-recover under strong interference conditions, which is the key link for the entire marking system to achieve stable operation, high-precision output and error suppression.

[0087] S4, on the basis of trajectory reconstruction, perform laser path stability evaluation, analyze the displacement change of laser trajectory between consecutive frames, calculate the trajectory consistency index, and output the trajectory reliability index for verifying the trajectory reconstruction effect;

[0088] To further verify whether the projection path after trajectory reconstruction has stability and repeatability, laser path stability evaluation needs to be performed on the basis of trajectory reconstruction. This evaluation process analyzes the changes in the spatial trajectory formed by the laser beam within consecutive time frames to determine whether it has unstable behaviors such as jumping, jittering, drifting, etc., and calculates the trajectory consistency index, finally outputting a trajectory reliability index for evaluating the reconstruction effect. The specific steps are as follows:

[0089] After the laser trajectory reconstruction is completed and the preliminary correction path is executed, the laser beam completes a pattern projection process in a medium-speed scanning manner, and forms a developed pattern on the photosensitive material surface. At this time, through the high-frame-rate image acquisition device arranged in front of the working face, the entire laser scanning process is photographed at a sampling frequency of not less than 60 frames per second, and the actual motion trajectory of the laser beam in space is captured in the continuous frames. The collected images need to have sub-pixel level resolution to ensure the accuracy of the subsequent path edge extraction and corner positioning operations. The shooting time lasts throughout the projection period, from the beginning of the laser beam to draw the first control point to the completion of all boundary closure.

[0090] The collected image sequence is input to the trajectory comparison process in chronological order, and the laser trajectory lines in each frame image are edge extracted and vectorized reconstructed. The specific method is to extract the center line position of the beam trajectory in each frame, and convert it into a sequence set composed of spatial coordinate points. Then, taking the time sequence as the reference, the spatial position change between the corresponding trajectory points in adjacent two frames is recorded as the difference data, and a trajectory jump curve graph is generated. For each jump point, the spatial displacement amplitude and the direction offset angle are calculated, the position and duration of the mutation behavior are marked, and a trajectory jump data set is formed to provide a basis for subsequent consistency judgment.

[0091] After obtaining the complete trajectory jump data, the trajectory consistency calculation is performed. The sliding time window method is adopted to statistically analyze the trajectory displacement of continuous frames, and the average offset value, the maximum jump amplitude, the direction fluctuation range and the path coincidence rate in the window are calculated. The path coincidence rate is defined as the degree of overlap of the trajectory points in space between the continuous frames, expressed in percentage, and the higher the value, the more stable the trajectory. In addition, the path smoothness index, i.e. the standard deviation of the curvature change of the trajectory per unit time, is also calculated to determine whether there is high-frequency jitter. The above indicators comprehensively reflect the stability of the current laser trajectory, and provide parameter basis for generating the trajectory reliability index.

[0092] According to the calculation results, the trajectory reliability index is constructed. The index is based on a weighted evaluation mechanism, which normalizes the path coincidence rate, the maximum jump amplitude, the curvature smoothness and the average direction offset, and gives them corresponding weights. The path coincidence rate has the largest weight to reflect the importance of trajectory repeatability. Finally, an real value between 0 and 1 is output as the trajectory reliability index, and the value closer to 1 represents higher stability and more reliable reconstruction effect. If the index is higher than the set threshold (such as 0.85), it is confirmed that the trajectory reconstruction effect is good, and the formal projection stage can be entered; if the index is lower than the threshold, the path fine tuning process is triggered, and the control instructions are optimized again to improve the trajectory stability.

[0093] The role of this step is to verify the dynamic stability of the reconstructed laser scanning path, to ensure that after completing the interference compensation and path repair, the laser beam can still maintain high consistency, high repeatability and high spatial accuracy in the actual operation process, so as to ensure that the mark pattern formed on the photosensitive material surface meets the engineering application requirements. After being affected by the electromagnetic interference of blasting, even if the laser control instruction has been corrected by trajectory reconstruction, due to the residual electrical noise, mechanical response lag of the laser head or weak disturbance of the driving instruction, the trajectory may still appear slight deviation, local jump or discontinuity of the trajectory segment in the projection process. These small unstable factors may appear as edge blur, pattern drift or corner misplacement in continuous frame images, which may still lead to mark misjudgment and drilling deviation if not identified and evaluated. Therefore, this step records the trajectory change process of the laser beam in the entire scanning period by setting a high frame rate image acquisition device, and extracts key indicators such as the deviation amplitude, jump rate and coincidence degree of the laser path in each time slice by comparing the spatial positions of the trajectory points between frames, and then calculates the trajectory consistency index. This index is used to reflect the stability of the laser trajectory in continuous time, and is a direct criterion for judging whether the trajectory reconstruction is effective and whether it can enter the formal marking link. Finally, by weighting and integrating multiple stability parameters, a quantitative trajectory reliability index is output, which provides an objective projection quality judgment basis for the system. This index is not only used to evaluate the reliability of the current trajectory, but also can be used as a reference variable for subsequent control strategy adaptive adjustment, which is a key link to realize intelligent and precise control of the laser marking closed loop.

[0094] S5, based on the trajectory reliability index, dynamically adjusting the scanning speed parameter and the laser power density parameter of the laser control system, so that the laser output characteristics and the photosensitive material response characteristics are matched, thereby improving the pattern clarity and spatial positioning accuracy of the laser marking;

[0095] In order to further improve the development quality and spatial accuracy of the projection pattern after trajectory reconstruction, the scanning speed parameter and the laser power density parameter of the laser control device need to be adjusted in real time according to the change result of the trajectory reliability index, so that the output characteristics of the laser beam and the photochemical response characteristics of the photosensitive material are dynamically matched. This process not only optimizes the action relationship between laser energy and material reaction, but also makes the projection pattern have clear boundaries, high contrast and coordinate consistency under different stable states. The specific steps are as follows:

[0096] After the trajectory reconstruction is completed and the path stability assessment is finished, the trajectory credibility index is obtained, which ranges from 0 to 1, representing the spatial consistency between the actual running trajectory of the laser beam and the reconstructed target trajectory. Three credibility level thresholds are set: greater than or equal to 0.90 is high credibility level, indicating that the trajectory is highly stable; between 0.75 and 0.90 is medium credibility level, indicating that the trajectory has small jumps but is overall coherent; less than 0.75 is low credibility level, indicating that the trajectory has obvious instability factors. According to the level, it is determined whether the current laser projection process needs to be adjusted and the adjustment strategy direction (speed up or power down or speed down and power up) to be adopted.

[0097] Enter the parameter matching phase, call the scanning speed and laser power density combination scheme corresponding to each credibility level. These parameters are constructed into a mapping table through pre-response curve testing of the development reaction of photosensitive materials under different energy densities. In the high credibility level, the scanning speed is 300 mm / s and the laser power density is 20 mW / mm2, emphasizing efficiency first; in the medium credibility level, the speed is 200 mm / s and the power density is 25 mW / mm2, considering reaction stability and clarity; in the low credibility level, the low speed is 120 mm / s and the high energy output is 30 mW / mm2, ensuring that even if the trajectory fluctuates slightly, the pattern can form a complete development structure. These parameter settings are matched through three sets of verified calibration data sets to ensure that each set of settings can form an optimal coupling with the color development curve range of the photosensitive coating.

[0098] The selected parameter combination is converted into control instructions in real time and sent to the driving execution link in the laser control device. Specifically, it includes: by modifying the motor drive pulse frequency setting value, the scanning speed is accurately adjusted; by adjusting the laser current output control value, the power density is dynamically changed. During the instruction loading process, to prevent control waveform jitter, a 150 ms instruction switching delay is set to ensure that the previous instruction is completely executed. Then, a full-width pattern projection is performed with the updated parameter combination, and an actual development pattern is formed on the photosensitive material surface to provide an analysis sample for the image verification link.

[0099] The image acquisition device installed on the working face is used to take a full picture of the pattern formed by the projection of the wheel, and the pattern edge line, corner point coordinates and line segment integrity index are extracted by combining digital image processing algorithm. The system compares the geometric characteristics of the collected pattern with the target contour in the design drawing at the coordinate level, analyzes the edge definition (measured by pixel gradient intensity), key point positioning error (calculated in millimeters) and pattern overall contour closure (expressed as path coincidence rate percentage). If all indicators meet the set standard (such as edge gradient greater than 0.8, key point error less than ±2mm, path coincidence rate greater than 95%), it is determined that the current parameter setting is effective, and the system enters the formal marking process. If one of the indicators does not meet the standard, the system automatically feeds back the current track reliability index and the actual developing error value to the control logic, modifies the parameter mapping relationship, and enters the next round of parameter fine-tuning and verification process.

[0100] The image acquisition device is a key component for realizing track stability evaluation and pattern developing verification, and its selection should be determined comprehensively considering factors such as construction environment characteristics, image precision requirements and projection surface spatial layout. In the application of working face laser marking, the image acquisition device can be specifically selected from the following types: first, high frame rate industrial camera, suitable for capturing dynamic information of track changes during laser scanning, frame rate not less than 60 frames per second, resolution better than 1920x1080 pixels; second, high-resolution line array camera, suitable for fine pattern edge recognition, especially suitable for static image acquisition of large-format projection area; third, laser three-dimensional contour camera, which can be used for capturing and compensating the geometric distortion of the marked pattern on the non-flat working face; fourth, image acquisition device with infrared filter function, which can enhance the photosensitive ability of the laser beam in the weak developing state and improve the imaging contrast of the low reflectivity photosensitive material surface.

[0101] The installation position of the image acquisition device should be scientifically laid out according to the geometric form of the working face, the projection angle, the light beam diffusion path and the site shielding condition. Generally, it is recommended to install the image acquisition device in the upward diagonal direction above the laser projection device, with an elevation angle of 30 to 45 degrees, a distance from the projection area not less than 1.5 meters and a maximum distance of 3 meters, to ensure that the acquisition angle covers the entire projection pattern area and avoids dead angles or shielding. At the same time, it is necessary to avoid the main traffic area of the working face personnel to reduce human interference and vibration influence. For curved, irregular or multi-level rock surface structure, multiple image acquisition devices can be set up to form a joint viewing angle to realize multi-angle pattern reconstruction and coordinate fusion, thereby improving the spatial consistency of image analysis and the projection verification precision.

[0102] The role of this step is to dynamically optimize the output parameters of the laser control system according to the real-time stability state of the laser projection trajectory, so that the laser beam is always in the best developing condition during the scanning process on the photosensitive material surface, thereby improving the clarity and spatial positioning accuracy of the marked pattern. In actual construction environment, the working face is often accompanied by factors such as vibration, dust, electromagnetic interference, etc. Even if the path geometry error is corrected after trajectory reconstruction, it may still cause problems such as blurred pattern boundary, uneven brightness or incomplete marking due to insufficient laser beam energy density, too fast scanning speed or photosensitive material response lag. Therefore, a control mechanism with real-time sensing and adaptive adjustment capability is needed, which takes the trajectory reliability index as an input variable to determine the laser control strategy according to its level. When the trajectory reliability is high, it indicates that the system is stable, at which time the scanning speed can be appropriately increased to improve the work efficiency, and the power density can be reduced to reduce the excessive exposure of the photosensitive material; when the trajectory reliability is low, the system automatically reduces the scanning speed, increases the laser power density, and prolongs the single-point exposure time to improve the photosensitive reaction activation degree, ensuring that even if the trajectory is slightly offset, the marked pattern can still be complete and clear. Through this closed-loop control method, the laser output characteristics can be flexibly adjusted according to the real-time trajectory quality, and the developing characteristics of the photosensitive material are highly matched, thereby significantly improving the marking consistency, pattern edge sharpness and spatial positioning accuracy under different stability conditions, which is the core technical link to realize high-robustness and high-quality laser marking.

[0103] S6, the developing quality index of the laser marked pattern formed on the surface of the photosensitive material and the positioning error of the actual projection position are input into the electromagnetic pulse interference dynamic monitoring model as feedback information, the interference recognition parameters and control compensation strategy are updated in real time, a closed-loop mechanism of interference analysis, trajectory recognition and control adjustment is constructed, and stable operation and high-precision marking effect of the laser marking system in a high-interference environment are realized.

[0104] To realize the continuous adaptation and precision maintenance of the system to the blasting electromagnetic interference, a closed-loop control mechanism with projection effectiveness as feedback basis needs to be further introduced after trajectory reconstruction and parameter adjustment. This mechanism takes the actual laser pattern formed on the surface of the photosensitive material as the core analysis object, and comprehensively extracts and quantizes the developing clarity and coordinate deviation as the direct basis for adjusting the recognition parameters and control compensation strategy, continuously corrects the system response mode, and constructs a feedback closed loop of "interference analysis-trajectory recognition-control adjustment". The specific steps are as follows:

[0105] After the completion of the laser marking task, a high-definition industrial camera set at 3 meters above the working face and at a 35-degree downward angle captures the full-width image of the photosensitive material surface. The selected image capture device is a 2 million-pixel global shutter camera, with a shutter time of 1 / 1000 seconds and a sampling frequency of 60 frames per second, ensuring that clear and motion-blur-free pattern images can be obtained under complex lighting conditions in the field. During the capture process, an active light supplement device is used to improve the visibility of the marking boundary. After the image data is transmitted to the processing terminal, edge detection (using the Canny operator), feature point extraction (using the Harris corner point algorithm), and pattern reconstruction operations are performed in sequence to obtain the boundary profile, polygon vertex coordinates, and gray scale distribution of each pixel region of the complete developed pattern.

[0106] The image processing results are input into the error analysis process to extract two types of indicators: the first is the development quality indicators, including edge sharpness (represented by the average pixel gradient), internal gray scale uniformity (measured by the standard deviation of gray scale), and contour closure degree (calculated by the percentage of boundary overlap); the second is the spatial positioning error indicators, which are obtained by comparing the coordinates of the pattern geometric center and each corner point with the coordinates of the same positions in the design drawing using the Euclidean distance calculation method, outputting the coordinate error in millimeters, and forming a projection deviation distribution map. All indicators are normalized to make the sharpness and coordinate error comparable, and a composite feedback variable between 0 and 1 is synthesized, with a value closer to 1 indicating a worse development effect and a larger projection error.

[0107] The composite feedback variable is used as the adjustment signal input into the electromagnetic interference recognition and control logic, and three types of core parameters are updated in real time: the electromagnetic interference recognition sensitivity threshold, which tightens the interference recognition trigger voltage fluctuation amplitude from ±3% to ±1.5%; the trajectory jump recognition tolerance, which reduces the allowed trajectory jump distance from 5 millimeters to 2 millimeters to enhance the path deviation detection accuracy; and the control compensation strategy parameters, including the laser scanning speed adjustment step (reduced from 50 millimeters per second to 20 millimeters per second) and the power density compensation amplitude (increased from 5 milliwatts per square millimeter to 10 milliwatts per square millimeter). All parameter updates use linear interpolation to ensure smooth adjustment without sudden changes and to avoid secondary disturbances to the system.

[0108] The updated control parameters are applied to the next round of laser marking tasks, and the current round of development and error analysis data are retained as historical references for subsequent trend evaluation and adaptive parameter adjustment. After every three rounds of closed-loop execution, the system reassigns the weights of the interference source influence factors in the electromagnetic interference model using the current total historical feedback variables as input, updates the interference space distribution estimation map, and makes the future recognition of the system in the same working face area more targeted and forward-looking.

[0109] The step is to establish a dynamic closed-loop control mechanism with laser marking results as the core feedback source. Through real-time analysis of the development quality and projection deviation, the results are fed back to the electromagnetic interference monitoring and control process, thereby realizing the adaptive optimization and high-precision stable operation of the system in the continuous blasting interference environment. In practical application, the tunnel or mine face is often in complex working conditions such as strong electromagnetic interference, high vibration and low light. Even after the pre-stage trajectory reconstruction and parameter adjustment, the laser control device may still deviate slightly or develop insufficiently due to environmental disturbance. Traditional laser projection systems often lack real measurement verification of the marking effect after outputting the command, resulting in the inability to identify or correct the wrong trajectory, affecting the accuracy of subsequent drilling operations. By taking the pattern formed on the photosensitive material surface as the "output feedback", extracting development quality indicators such as pattern edge sharpness, gray scale uniformity, and boundary closure, and comparing the spatial deviation of the corner points and center points in the design graph coordinates and the actual developed pattern, an evaluation model for quantifying the laser output precision can be constructed. Based on these evaluation results, the system dynamically adjusts the recognition threshold, interference response sensitivity, trajectory deviation judgment standard and control instruction correction rules in the electromagnetic interference monitoring model, so that the recognition logic and interference field change evolve synchronously, and the control strategy is updated in real time according to the trajectory stability, thereby forming a closed-loop control chain. This mechanism enables the system to have a "result-oriented" intelligent reaction capability. After each interference impact, the actual marking effect is used as the basis to correct the front-end recognition and judgment and the back-end control output, realize the continuous iteration of recognition, response and correction, and significantly improve the robustness, reliability and projection precision of the laser marking system in complex working conditions. It is a key technology link to realize intelligent and high-robustness operation.

[0110] Through the above-mentioned photosensitive material and laser mapping-based face hole visual marking method, an electromagnetic interference-resistant laser marking closed-loop control system can be effectively constructed to realize the whole-process response from electromagnetic interference perception, trajectory recognition and correction to adaptive adjustment of control parameters. This method not only can accurately identify and quantify the intensity and source of electromagnetic pulse interference in the blasting construction environment, but also can guide the high-precision reconstruction of the subsequent projection trajectory through real-time extraction and risk assessment of the laser control instruction deviation trajectory. Further combined with trajectory stability analysis and credibility index output, the scanning speed and power density are dynamically adjusted to form the best match between laser output behavior and photosensitive material development reaction characteristics, ensuring that clear and accurate marking patterns can still be obtained in a complex interference background. Finally, by taking the actual development quality and position error of the marking pattern as feedback variables, the interference monitoring model is introduced for parameter self-learning and recognition strategy iteration to form an intelligent closed loop of "recognition-correction-verification-optimization", effectively avoiding drilling misjudgment and blasting accidents caused by "ghost" marking, and greatly improving the automation, safety and construction efficiency of the face hole drilling operation.

[0111] The foregoing merely illustrates some exemplary embodiments of the application, and it will be appreciated that those skilled in the art will be able to devise various modifications without departing from the spirit and scope of the application. The appended drawings and description are illustrative only, and are not intended to be limiting.

Claims

1. A visual marking method for boreholes at the working face based on photosensitive materials and laser mapping, characterized in that, Includes the following steps: S1. In the blasting construction environment, the real-time changes of current signals, voltage signals and control command signals of the laser control system are collected to construct a dynamic monitoring model of electromagnetic pulse interference, extract the time-frequency characteristics of electromagnetic disturbances, and generate an interference intensity distribution map to identify electromagnetic interference sources and their distribution. S2, based on the interference intensity distribution map, extract the command offset trajectory of the laser control system, calculate the jump amplitude and duration, and output the interference risk level to evaluate the stability of the control system. S3, based on the interference risk level, performs real-time trajectory reconstruction of the laser projection path, and corrects the direction and position offset of the laser beam by comparing the historical trajectory with the current trajectory, so that the projection trajectory is aligned with the preset coordinates; S4, based on trajectory reconstruction, performs path stability assessment and outputs trajectory credibility index through inter-frame trajectory consistency analysis to verify the reconstruction effect; S5, based on the trajectory reliability index, dynamically adjusts the laser scanning speed and power density parameters to match the laser output characteristics with the development response characteristics of the photosensitive material, thereby improving the marking clarity and positioning accuracy; S6 uses the development quality and positioning error of the laser marking pattern as feedback information to input into the interference dynamic monitoring model, updates the interference identification parameters and control compensation strategies in real time, and constructs a closed-loop mechanism for analysis, identification and control.

2. The method for visual marking of boreholes at the working face based on photosensitive materials and laser mapping according to claim 1, characterized in that, Step S1 includes: The three-channel acquisition device is connected to the DC power supply circuit of the laser control device, the output circuit of the servo driver and the laser scanning command signal path respectively. The sampling accuracy is higher than 16 bits and the sampling frequency is 20kHz. After acquiring the change data of current signal, voltage signal and control command signal, fast Fourier transform, short-time Fourier transform and wavelet packet decomposition are performed respectively to extract the maximum spectral amplitude, main frequency shift rate, pulse peak energy and duration characteristics. A two-dimensional interference intensity distribution map is constructed based on the time-frequency characteristics of the three types of signals. The horizontal axis represents the signal path sequence, the vertical axis represents the blasting time window, and the color code represents the interference energy density. Based on the interference amplitude and duration of each path in the figure, the risk value is calculated and the interference level is classified for subsequent laser trajectory correction and operation window scheduling control.

3. The method for visual marking of boreholes at the working face based on photosensitive materials and laser mapping according to claim 1, characterized in that, Step S2 includes: The control command trajectory is extracted based on the interference intensity distribution map, and the spatial offset and jump speed of each trajectory point are calculated. The central difference method is used to extract the trajectory velocity change rate, and third-order median filtering is used to remove signal noise and extract the real trajectory jump behavior. Construct a comprehensive index function for anti-interference performance, integrate offset amplitude, jump rate and duration of continuous anomaly according to weight, and output the anti-interference risk coefficient. Risk levels are classified based on the anti-interference risk coefficient: if it is higher than 0.75, the task is terminated; if it is between 0.45 and 0.75, the trajectory is reconstructed; if it is lower than 0.45, the current task is maintained and monitoring continues.

4. The method for visual marking of boreholes at the working face based on photosensitive materials and laser mapping according to claim 3, characterized in that, The specific steps for constructing the comprehensive index function of anti-interference performance are as follows: Extract the spatial offset amplitude of each control point in the laser control command trajectory, and calculate the maximum instantaneous offset value as a reference index for offset amplitude; The velocity change rate of the trajectory points is processed by the central difference method, and the maximum angular velocity change rate is extracted as a reference index for the jump rate. The duration of consecutive abnormal segments in the detection trajectory is used as a time dimension indicator to calculate the duration of the jump. The offset magnitude, jump rate, and duration are assigned weights of 0.5, 0.3, and 0.2, respectively. A normalized anti-interference risk coefficient is constructed by linear weighting and used as the basis for evaluating the stability level of the control system.

5. The method for visual marking of boreholes at the working face based on photosensitive materials and laser mapping according to claim 1, characterized in that, Step S3 includes: Determine if the interference risk level is greater than or equal to 0.

45. If it is, call the historical projection trajectory recorded in the same face area of ​​the previous blasting cycle as the standard trajectory. Collect current laser scanning trajectory data and compare it with historical trajectories point by point according to time number, extract the lateral and longitudinal offset values ​​of each point and generate a trajectory error distribution table; The weighted least squares method is used to fit the offset point, and a correction vector is constructed based on the offset magnitude and the importance of the geometric structure to replace the coordinate and angle parameters in the original control command. The corrected trajectory is virtually marked with reduced power. The pattern is then judged based on the image acquired by the image sensor to determine whether the offset does not exceed ±2 mm. If it does, the formal marking is performed.

6. The method for visual marking of boreholes at the working face based on photosensitive materials and laser mapping according to claim 5, characterized in that, Step S4 includes: A high frame rate image acquisition device is used to record the projection process of a laser beam on the surface of a photosensitive material at a frequency of more than 60 frames per second, thereby obtaining a sequence of spatial trajectory images within a continuous time frame. Edge extraction and vectorization are performed on the image sequence to obtain the set of spatial coordinate points of the laser trajectory in each frame, and the spatial displacement and orientation change of the trajectory points between adjacent frames are calculated. The sliding time window method was used to analyze the trajectory offset characteristics between consecutive frames, and the path overlap rate, maximum jump amplitude, directional fluctuation range and standard deviation of curvature change were calculated. After normalizing the acquired parameters, the parameters are summed according to their weights to output the trajectory confidence index. If the trajectory confidence index is higher than 0.85, the trajectory reconstruction is deemed valid and the formal projection process begins.

7. The method for visual marking of boreholes at the working face based on photosensitive materials and laser mapping according to claim 6, characterized in that, Step S5 includes: Based on the level of the trajectory confidence index, select the corresponding combination of scanning speed and power density parameters; The scanning speed is set by adjusting the motor drive pulse frequency using control commands, and the laser current output value is simultaneously adjusted to set the power density. Perform pattern projection and acquire developed pattern images through an image acquisition device, and analyze the indicators of edge sharpness, positioning error and path overlap rate; Determine whether the development index meets the set standard. If it does, proceed to the formal marking process. If it does not, provide feedback to correct the trajectory confidence index and parameter mapping relationship and perform parameter fine-tuning.

8. The method for visual marking of boreholes at the working face based on photosensitive materials and laser mapping according to claim 1, characterized in that, Step S6 includes: Collect image data and extract pattern boundary, corner coordinates and grayscale distribution information to obtain development quality indicators and positioning error indicators; The development quality index and the positioning error index were normalized and synthesized into a composite feedback variable; The electromagnetic interference identification sensitivity threshold, trajectory jump identification tolerance, and control compensation strategy parameters are updated based on composite feedback variables. The updated control parameters are applied to the next round of laser marking tasks and executed in a closed loop. The interference spatial distribution estimation map is periodically reconstructed to improve the subsequent recognition accuracy.

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