Laser show safety regulation method and system based on digital twinning

Abstract

This invention relates to the field of laser control technology and discloses a method and system for safe control of laser performances based on digital twins. The method includes: constructing a digital twin model that is synchronized in real time with the physical laser performance site; performing real-time safety situation awareness based on this model, and generating a real-time safety index by calculating and weighting four-dimensional risk factors: energy density, pattern dynamics, equipment status, and environmental interference; classifying and judging according to the real-time safety index; if the risk level is medium, implementing a virtual electronic channel active constraint strategy; if the safety threshold is reached, implementing an emergency stop strategy; and returning to the monitoring step after triggering the response to form a closed-loop control. This invention represents a progress from passive response to proactive pre-control, ensuring absolute personal safety while maintaining the artistic continuity of the performance, and is suitable for high-power, high-complexity laser performance scenarios.

Description

Technical Field

[0001] This invention relates to the field of laser control technology, specifically a method for safe control of laser performances based on digital twins. Background Technology

[0002] Laser shows are a stage and outdoor audiovisual performance that uses a controlled laser beam as its core, generating light spots, lines, or complex scanning trajectories through high-speed scanners to display dynamic patterns and color effects. Despite their strong visual impact and expressiveness, laser beams are inherently high-energy light radiation, posing significant safety risks. If a laser beam or its scattered or reflected light directly or indirectly shines into the eyes or skin, it may cause retinal burns, vision damage, or skin burns. In complex venues, the interaction between the laser beam and reflective objects, temporary structures, or reflective objects carried by the audience may lead to unpredictable dangerous paths. Therefore, the safety control and management of laser shows is particularly important.

[0003] Current laser shows rely heavily on static thresholds or simple hardware interlocks to ensure the safety of people and venues. Static thresholds are difficult to balance the continuity of the performance under high-power complex patterns with safety under extreme environmental disturbances, and are prone to false triggering during the artistic climax or insufficient response to sudden disturbances. They also mostly use independent sensors to detect and trigger the blocking, lacking a comprehensive assessment of the complexity of the performance pattern, scanning dynamics and environmental disturbances. Summary of the Invention

[0004] In response to the problems in related technologies, this invention provides a laser performance safety control method based on digital twins to overcome the aforementioned technical problems in existing related technologies.

[0005] To solve the aforementioned technical problem, the present invention is achieved through the following technical solution:

[0006] On the one hand, this invention provides a method for safe control of laser performances based on digital twins, specifically including the following steps:

[0007] Step 1: Establish a virtual model in the digital environment that is synchronized with the live laser show and use a unified time reference to map the execution data, status data and environmental data to the virtual model in real time;

[0008] Step 2: Calculate energy risk factors, pattern dynamic risk factors, equipment status risk factors, and environmental disturbance factors based on the virtual model, and then weight and fuse them according to preset weights to obtain a real-time safety index.

[0009] Step 3: Based on the real-time security index, trigger the virtual channel constraint strategy within the preset security range or trigger the emergency stop strategy when the index falls below the lower threshold.

[0010] Step four: After any emergency response, return to step two to form a closed-loop monitoring and control system.

[0011] Preferably, the execution data includes the actual output power of the actual laser emitter, the actual deflection angle of the galvanometer, and the command position of the galvanometer; the status data includes the cavity temperature of the laser emitter and the motor temperature of the galvanometer; and the environmental data includes the wind speed, wind direction, and ambient temperature at the performance site.

[0012] Preferably, energy risk factors are calculated based on virtual models:

[0013] The beam propagation distance is obtained by adding the fixed optical path length from the laser exit to the current scanning position to the distance from the current position of the beam to the nearest boundary of the audience area. Assuming the beam is an ideal Gaussian beam, the beam radius when it reaches the boundary of the audience area is calculated based on the beam propagation distance, the initial spot diameter at the laser exit, and the beam divergence angle. Then, the spot area of ​​the beam is calculated based on the spot radius. The irradiance when the beam reaches the boundary of the audience area is obtained by dividing the actual output power of the laser by the spot area.

[0014] The maximum acceptable irradiance for the human eye under different conditions is obtained. The real-time exposure irradiance is compared with the maximum permissible irradiance, and a safety margin coefficient is introduced. The energy risk factor is obtained by calculating and analyzing the normalized ratio.

[0015] Preferably, the pattern dynamic risk factor is calculated based on a virtual model:

[0016] Extract the control point data set to construct the desired motion trajectory of the virtual beam path; the control point data set includes a timestamp, X-axis command position, Y-axis command position, and laser modulation signal for each control point; perform real-time analysis on the currently executed performance pattern segment, extract the instantaneous scanning speed, path curvature, and scanning acceleration, and calculate the pattern dynamic risk factor using a formula.

[0017] Preferably, the equipment status risk factor is calculated based on a virtual model:

[0018] The equipment status risk consists of thermal load risk and tracking accuracy risk. The thermal load corresponding to the laser cavity temperature and galvanometer motor temperature is obtained by substituting them into the normalized ratio formula, and the largest of them is selected as the thermal load risk factor. The current position of the beam is extracted, and the distance between it and the expected position in the expected motion trajectory of the virtual beam path is calculated to obtain the real-time error. The tracking error is quantified by the normalized ratio formula to directly reflect the dynamic response performance of the equipment, and the tracking accuracy factor is obtained.

[0019] According to the actual emphasis weight, a weight is assigned to the heat load risk factor and the tracking accuracy factor respectively. Then, the load risk factor and the tracking accuracy factor are linearly weighted and fused to obtain the equipment status risk factor based on the assigned weight.

[0020] Preferably, the calculation of environmental disturbance factors based on the virtual model includes: estimating the wind-induced angular offset by the current wind speed and the angle between the wind direction and the structure-sensitive direction, and then calculating the environmental disturbance factor by using the offset through a normalized ratio formula.

[0021] Preferred virtual channel constraints:

[0022] Based on the current beam position and direction of motion, a virtual electronic channel is dynamically generated in virtual space. The virtual electronic channel is a three-dimensional cone-shaped region centered on the current beam position and with the beam propagation direction as its axis, with a cone angle α=θ. beam ·k channel , where k channel θ is the channel relaxation factor. beam The nominal safety envelope angle is obtained by summing the beam divergence angle, the tracking error reduction angle, the wind-induced angular offset, and the fixed safety margin angle. The tracking error reduction angle is obtained by dividing the real-time tracking error by the fixed optical path length from the laser exit to the current position of the beam.

[0023] The boundary of the virtual electronic channel is defined as an absolutely forbidden safety boundary. The predicted beam path is obtained by extrapolating the velocity vector of the beam at the current position to the trajectory of a fixed future time. It is then determined whether the predicted beam path will exceed the range of the virtual electronic channel. If it is predicted that the beam will exceed the boundary of the virtual channel, a virtual channel warning is generated and active avoidance control is immediately initiated.

[0024] The active avoidance control includes: sending a correction command to the galvanometer to adjust the beam direction and keep it in the center of the channel, and simultaneously sending a power limiting command to the laser controller to limit the output power to the current value Q1; where Q1 is a percentage, Q1∈(0,100%); if the virtual channel warning is triggered for three consecutive control cycles, the actual laser output power is automatically gradually reduced to Q2 until the risk is eliminated; where Q2 is a percentage, Q2∈(20%,80%).

[0025] Preferred emergency stop strategy:

[0026] Immediately send a power attenuation command to the laser emitter, controlling the laser to linearly attenuate its output power to a safe level within a fixed time period. The specific safe level of the output power is determined according to the Class 1 emission limit achievable for the corresponding laser wavelength λ in the IEC 60825-1 standard. Simultaneously, send a safe position command to the galvanometer, controlling the galvanometer to guide the beam towards a preset safe absorption trap within a limited time. The safe absorption trap is a completely enclosed area in the physical space with no audience and a high absorption rate. After the power attenuation is complete and the beam has been guided to a safe direction, send an emergency stop status signal to the backstage laser performance control staff.

[0027] On the other hand, the present invention provides a laser performance safety control system based on digital twins, specifically including:

[0028] The digital modeling module creates a virtual model in the digital environment that is synchronized with the live laser show and uses a unified time reference to map execution data, status data and environmental data to the virtual model in real time.

[0029] The real-time monitoring module calculates energy risk factors, pattern dynamic risk factors, equipment status risk factors, and environmental disturbance factors based on a virtual model, and then weights and fuses them according to preset weights to obtain a real-time safety index.

[0030] The safety control module triggers a virtual channel constraint strategy within a preset safety range based on the real-time safety index, or triggers an emergency stop strategy when the value falls below the lower threshold. After any emergency response, it returns to the real-time monitoring module to form a closed-loop monitoring and control system.

[0031] The present invention has the following beneficial effects:

[0032] 1. By establishing a unified time benchmark and adopting a time protocol to ensure the time synchronization of execution data, status data, and environmental data, the actual execution data, status data, and environmental data are mapped to a digital virtual model. By constructing a digital twin model that is highly synchronized with the physical laser performance site and establishing real-time acquisition and synchronous mapping of multi-source heterogeneous data, the digital mapping and two-way synchronization of all elements of the laser performance are realized.

[0033] 2. Based on the synchronized digital twin, risks are quantified from four dimensions: optical energy density, pattern dynamics, equipment status, and environmental disturbances, and then fused into a single real-time safety index with configurable weights. This feature enables a comprehensive, comparable, and dynamic quantitative assessment of the safety status of laser performances. It breaks through the limitations of traditional static threshold judgments and can identify risk sources such as energy concentration, galvanometer out-of-sync, or sudden environmental changes in advance, providing a reliable basis for refined and graded intervention.

[0034] 3. A three-level response is implemented within a given safety range. The three levels of response include: no intervention, virtual channel constraint, and emergency stop. The virtual channel constraint dynamically generates a three-dimensional conical electronic channel with the current beam position and propagation direction as the axis and performs trajectory correction and power limiting. The emergency stop involves linearly decaying the power within a short period of time and guiding the beam to the safety absorption trap, which is then released after manual reset. The three-level response is based on the risk gradient and implements gradual intervention from soft constraints to forced shutdown. The technical effect is that it can maintain the continuity of the performance with minimal intrusion under medium risk and maximize the safety of the audience and equipment with an extremely short response time under extreme risk. The on-site execution data after each emergency response is continuously transmitted back and mapped to the digital twin, and the risk calculation and decision-making steps are executed cyclically to form an uninterrupted closed-loop control.

[0035] Of course, any product implementing this invention does not necessarily need to achieve all of the advantages described above at the same time. Attached Figure Description

[0036] To more clearly illustrate the technical solutions of the embodiments of the invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the invention. For those skilled in the art, the drawings can be obtained from these drawings without creative effort.

[0037] Figure 1 This is a schematic diagram of the method flow of the present invention;

[0038] Figure 2 This is a schematic diagram of the structural connection of the present invention. Detailed Implementation

[0039] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0040] This invention provides a method and system for safe control of laser performances based on digital twins, which will be described below in conjunction with... Figure 1 and Figure 2 The specific implementation method is described in detail. This embodiment takes a laser performance site as a specific application scenario. By constructing a digital twin model that is synchronized with the physical laser performance system in real time, and by real-time security situation awareness and trend prediction, a hierarchical and adaptive security control strategy is realized.

[0041] like Figure 1 As shown, the laser performance safety control method based on digital twins includes:

[0042] Step one involves establishing a virtual model synchronized with the live laser show in a digital environment, ensuring bidirectional synchronization of data flow between the virtual and physical spaces; specifically including:

[0043] Based on precise surveying data of the performance venue, a 3D scene model is constructed in the virtual environment, including the laser emitter's position and orientation, scanning area boundaries, audience area boundaries, stage equipment area, building facades, and potential reflective surfaces. All safety-related areas are labeled as virtual geometries with specific attributes, with the audience area boundary marked as a primary safety boundary prohibiting beam intrusion, and the stage equipment area marked as a secondary safety boundary. Virtual lasers in the virtual environment are assigned parameter attributes consistent with physical equipment, including wavelength, rated output power, beam divergence angle, initial beam diameter, and modulation response time. Similarly, virtual galvanometers are assigned dynamic parameters, including maximum scanning angle range, maximum angular velocity, frequency response characteristic curve, tracking error calibration value, and thermal drift coefficient. Standard format performance files are imported and parsed into a time-series set of control point data, where each control point includes a timestamp, X-axis command position, Y-axis command position, and laser modulation signal. This data set constitutes the desired motion trajectory of the virtual beam path.

[0044] The system monitors the real laser emitter, galvanometer, and performance environment in real time to collect execution data, status data, and environmental data, and updates them to the digital virtual model in real time. Execution data includes the actual output power of the real laser emitter, the actual deflection angle of the galvanometer, and the galvanometer command position (X-axis command position and Y-axis command position). Status data includes the cavity temperature of the laser emitter and the motor temperature of the galvanometer. Environmental data includes the wind speed, wind direction, and ambient temperature at the performance site.

[0045] Establishing a unified time benchmark and employing a time protocol to ensure the time synchronization of execution data, status data, and environmental data, then mapping the real-world execution data, status data, and environmental data to a digital virtual model; constructing a high-fidelity synchronized digital twin model with the physical laser performance venue, and establishing real-time acquisition and synchronous mapping of multi-source heterogeneous data, achieving digital mapping and two-way synchronization between the virtual and real worlds for all elements of the laser performance; further, by establishing a unified time benchmark and employing a precise time protocol to ensure the synchronous mapping of execution data, status data, and environmental data, solving the registration problem of multi-source heterogeneous data in time and space, enabling the digital twin to reflect the real state of the physical entity in real time and accurately, providing a complete, accurate, and synchronized data foundation for all subsequent safety analysis and control, which is the fundamental prerequisite for the entire solution to achieve the leap from passive response to proactive prevention and control.

[0046] Step two involves performing real-time security situation awareness based on the synchronized data twin, calculating and outputting the real-time security coefficient; the specific process is as follows:

[0047] S2-1, When the laser beam propagates in the far field, its spot diameter increases linearly with the propagation distance. In this embodiment, assuming the beam is an ideal Gaussian beam, the spot radius when it reaches the boundary of the audience area is r(t): Where d0 refers to the initial spot diameter at the laser exit, calculated in meters; θ is the beam divergence angle; d(t) is the beam propagation distance, i.e., the total path length of the beam from the laser exit to the boundary of the audience area, which is equal to the fixed optical path length from the laser exit to the current scanning position plus the distance from the current position of the beam to the nearest boundary of the audience area, calculated in meters; t is the laser irradiation time index, in the formula... This represents the radius increment caused by the beam divergence angle; then, the beam spot area A(t) is calculated based on the spot radius r(t), using the following formula: Assuming that the power attenuation of the laser beam along its entire propagation path is negligible due to minimal air absorption, the irradiance at the boundary of the viewer's area when the beam reaches the actual output power of the laser is divided by the beam area. This irradiance is calculated using the following formula: Where P(t) is the actual output power of the laser, calculated in watts; irradiance E(t) is the actual power per unit area that the eyes or skin of the audience can receive when the beam just happens to sweep across the boundary of the audience area, i.e., the exposure irradiance; the greater the exposure irradiance, the greater the safety risk; it should be noted that the main threat of laser to personal safety lies in whether the irradiance per unit area exceeds the safety tolerance of the human body or eyes when the beam propagates to the boundary of the audience area. If it does, the beam will cause harm to the eyes and body of the audience. Therefore, it is necessary to calculate the actual irradiance of the laser beam when it reaches the boundary of the audience area, rather than the irradiance of the beam at the current position;

[0048] According to the international laser safety standard IEC60825-1, the maximum permissible irradiance for the human eye under different conditions is obtained. For continuous wave lasers, the calculation of the maximum irradiance is related to the wavelength and irradiation time. Typically, the human eye's blink reflex time of 0.25 seconds is taken as the worst-case scenario. In this embodiment of continuous wave laser, the formula for calculating the maximum permissible irradiance is: Where Δt is the exposure time, which in this embodiment uses the human eye avoidance reaction time, and is set to 0.25 seconds; C4 is the wavelength correction factor, which varies for different visible light bands. For example, the wavelength correction factor C4 for the 400-700nm visible light band is 1, and the correction factor C4 for the 700-1050nm band is 1. λ refers to a laser wavelength in the near-infrared band from 700nm to 1050nm.

[0049] The real-time exposure irradiance E(t) is compared with the safety limit (maximum permissible irradiance), and a safety margin coefficient is introduced. The energy risk factor is obtained by calculating and analyzing the normalized ratio; the calculation formula is: , where k safe Basic safety margin factor, dimensionless, k safe >1; In this embodiment, it is set to 2.0; The basic safety margin coefficient means that the maximum allowable safety threshold is k of Emax. safe The purpose of setting it to a factor greater than 1 is to compensate for model errors, sensor measurement errors, and to provide an additional safety buffer to prevent the Emax critical value from being reached due to instantaneous fluctuations. According to the calculation process of the energy risk factor, its value ranges between [0,1]. The larger the value, the greater the energy-related risk of the beam.

[0050] S2-2, the patterns in laser performances are formed by high-speed scanning of galvanometers. When performing complex patterns such as high-speed sharp angle turns, dense filling, or high-frequency reciprocating scans, the galvanometers are subjected to extremely high acceleration and torque loads, which can cause the actual position of the galvanometers to lag behind the commanded position. This results in the beam path deviating from the expected position, increasing tracking errors, and the scanning frequency approaching the natural frequency of the galvanometer's mechanical structure, causing abnormal vibrations and mechanical resonance. At sharp angle turns, the galvanometers may repeatedly return and descend after passing the target position due to inertia, causing overshoot and oscillations. These anomalies can cause the actual beam path to deviate from the designed path, potentially leading to accidental entry into the target area or excessive energy concentration. Therefore, it is essential to accurately measure the dynamics of the pattern itself.

[0051] The control point data set is extracted to construct the desired motion trajectory of the virtual beam path. Each control point data set includes a timestamp, X-axis command position, Y-axis command position, and laser modulation signal. Real-time analysis is performed on the currently executed performance pattern segment, extracting the instantaneous scanning velocity, path curvature, and scanning acceleration, denoted as V(t), q(t), and a(t), respectively. The scanning acceleration is obtained by performing a short-time Fourier transform on the galvanometer position command. The formula is used to... The pattern dynamic risk factor is calculated, where Vmax is the maximum safe scanning speed of the galvanometer, qmax is the maximum allowable curvature, amax is the acceleration limit, and w1, w2, and w3 are the weighting factors for the instantaneous velocity, curvature, and acceleration terms, respectively, satisfying w1+w2+w3=1; in this embodiment, w1, w2, and w3 are taken as 0.4, 0.4, and 0.2, respectively.

[0052] S2-3, Under prolonged high-load operation, the laser and galvanometer temperatures of laser performance equipment rise, leading to thermal deformation of optical components, beam drift, and shortened lifespan, resulting in heat accumulation. The servo system experiences thermal fatigue or wear, causing decreased dynamic response performance and increased tracking errors. Insufficient cooling system flow or clogged filters reduce heat dissipation capacity. Equipment status risk reflects the impact of the equipment's own health on safety and requires comprehensive assessment of both thermal load and tracking accuracy. Equipment status risk consists of thermal load risk and tracking accuracy risk. The thermal load corresponding to the laser cavity temperature and galvanometer motor temperature is obtained by substituting them into the normalized ratio formula, and the largest value is selected as the thermal load risk factor. The normalized ratio formula is: Where T and Tmax are the laser cavity temperature and the maximum allowable temperature of the laser, respectively, or the galvanometer motor temperature and the maximum allowable temperature of the galvanometer; k therm The thermal safety margin factor is set to 0.9 to allow for a temperature rise margin. In this embodiment, it is set to 0.9. The closer the laser cavity temperature and the maximum allowable temperature of the laser are to the limit, the higher the risk of equipment performance degradation, which may cause thermal drift or damage.

[0053] The current position of the light beam is extracted, and the distance between it and the corresponding expected position in the expected motion trajectory of the virtual light beam is calculated to obtain the real-time error. Similarly, the tracking error is quantified using a normalized ratio formula to directly reflect the dynamic response performance of the device, thus obtaining the tracking accuracy factor. The calculation formula is as follows: , where k track The tracking error safety margin coefficient is set to 0.8 in this embodiment; ε(t) is the real-time tracking error of the current position of the beam, and εmax is the maximum allowable tracking error; according to the actual emphasis weight, a weight is assigned to the heat load risk factor and the tracking accuracy factor respectively, and then the load risk factor and the tracking accuracy factor are linearly weighted and fused according to the assigned weight to obtain the equipment status risk factor;

[0054] S2-4, Environmental factors can interfere with the precise pointing of the laser beam and the stable operation of the equipment. Strong winds acting on the supporting structure cause low-frequency swaying of the beam direction; wind pressure is proportional to the square of wind speed, causing the supporting structure to generate overturning moment and vibration, which can be determined by the formula... Estimate the wind-induced angular offset to obtain the offset Δθ; where K is the structural wind load coefficient; V wind (t) represents the current wind speed, and φ(t) represents the angle between the wind direction and the structure's sensitive direction, which is calculated based on the wind direction sensor and the orientation of the supporting structure; then, it is normalized using the ratio formula. Calculate the environmental disturbance factor, where k windThe wind load safety margin factor is set to 0.7 in this embodiment, taking into account the dynamic amplification effect of wind load; θmax is the allowable angular offset tolerance, which is calculated based on the distance to the audience area boundary.

[0055] S2-5 assigns a weight to each of the energy risk factor, pattern dynamics risk factor, equipment status risk factor, and environmental interference factor. Based on these weights, the energy risk factor, pattern dynamics risk factor, equipment status risk factor, and environmental interference factor are weighted and fused to obtain a real-time risk index. The sum of each weight is one, and the weights can be configured according to the performance type and venue safety level. In this embodiment, the default weight assignments are as follows: energy density risk has the highest weight, 0.5; pattern dynamics risk has a weight of 0.2; equipment status risk has a weight of 0.15; and environmental disturbance risk has a weight of 0.15. The real-time risk index is then subtracted from one to map the real-time risk index to a real-time safety index S(t). It should be noted that the value of S(t) ranges from [0,1]. A higher S(t) value indicates a safer laser performance, while a lower S(t) value indicates a higher risk. When S(t) = 1, it indicates that the system is in an ideal safety state.

[0056] Based on the synchronized digital twin, risks are quantified from four dimensions: optical energy density, pattern dynamics, equipment status, and environmental disturbances, and then fused into a single real-time safety index with configurable weights. This feature enables a comprehensive, comparable, and dynamic quantitative assessment of the safety status of laser performances. It breaks through the limitations of traditional static threshold judgments and can identify risk sources such as energy concentration, galvanometer out-of-sync, or environmental abrupt changes in advance, providing a reliable basis for refined and graded intervention.

[0057] Step 3: Based on the real-time safety index S(t), perform real-time safety assessment and trigger corresponding emergency strategies to achieve immediate safety protection for the laser show; the specific process is as follows:

[0058] A preset safety range is defined, which can be set by the user based on on-site assessments of the laser show's pattern difficulty and performance environment. In this embodiment, the safety range is set to [0.4, 0.8]. The lower threshold of 0.4 is the absolute safety baseline derived from international laser safety standards. When the real-time safety index falls below this value, it has approached or exceeded the safety limits of the human body and equipment, requiring an unconditional emergency shutdown. The upper threshold of 0.8 is based on statistical analysis of a large amount of historical performance data and represents the upper limit of normal dynamic fluctuations of the equipment. Above this value, the system enters a low-risk stable zone, requiring no intervention. The range [0.4, 0.8] serves as a medium-risk warning range, used when potential disturbances occur but have not yet reached the emergency threshold. Active pre-control measures are initiated when the value is reached, thereby avoiding accidental shutdowns due to normal fluctuations while ensuring absolute safety, and achieving a dynamic balance between safety and artistic continuity. If the real-time safety index is greater than the maximum value of the safety range, it means that there is no obvious safety risk to the laser show at present, so no intervention is triggered, and the next cycle is directly entered, that is, the process returns directly and executes step two. If the real-time safety index is within the safety range, it means that the performance is within the medium risk warning range, with potential disturbances or dynamic pressures but not yet reaching the emergency threshold, so the virtual channel constraint strategy is executed. If the real-time safety index is less than the minimum value of the safety range, it means that the real-time risk is approaching or exceeding the safety limit, so the emergency stop strategy is executed.

[0059] The virtual channel constraint strategy specifically includes: dynamically generating a virtual electronic channel in virtual space based on the current beam position and direction of motion. This channel is a three-dimensional conical region centered on the current beam position and with the beam propagation direction as its axis, with a cone angle α = θ. beam ·k channel , where k channel θ is the channel relaxation factor, ranging from 1.2 to 1.5. beamThe nominal safety envelope angle is obtained by summing the beam divergence angle, tracking error conversion angle, wind-induced angular offset, and fixed safety margin angle. The tracking error conversion angle is obtained by dividing the real-time tracking error ε(t) by the fixed optical path length from the laser exit to the current position of the beam. The boundary of the virtual electronic channel is defined as an absolutely forbidden safety boundary. The predicted beam path is obtained by extrapolating the beam velocity vector at the current position to the trajectory in the next 50ms. It is then determined whether the predicted beam path will exceed the range of the virtual electronic channel. If it is predicted that the beam will exceed the virtual channel boundary, a virtual channel warning is generated, and active avoidance control is immediately initiated. The specific active avoidance control includes: sending a correction command to the galvanometer to adjust the beam direction to keep it in the center area of ​​the channel, and sending a power limit command to the laser controller to limit the output power to 80% of the current value. If the virtual channel warning is triggered for three consecutive control cycles, the actual laser output power is automatically gradually reduced to 50% until the risk is eliminated. It should be noted that when the power limit is reduced in actual laser performances, the reduction range is usually between 20% and 80%.

[0060] The emergency stop strategy specifically includes: immediately sending a power attenuation command to the laser emitter, controlling the laser to linearly attenuate its output power to a safe level within 2ms. The specific safe level of output power is determined according to the Class 1 emission limit achievable for the corresponding laser wavelength λ in the IEC 60825-1 standard. For the visible light band (400-700nm), this limit is 0.39mW. Simultaneously, a safe position command is sent to the galvanometer, controlling the galvanometer to guide the beam to a preset safe absorption trap direction within 5ms. The safe absorption trap is a completely enclosed area in the physical space with no audience and a high absorption rate, usually pointing towards an unobstructed area in the sky or a dedicated beam termination device. After the power attenuation is completed and the beam has been guided to a safe direction, an emergency stop status signal is sent to the backstage laser show control staff. The emergency stop status remains in effect until the staff manually confirms and resets it, ensuring that the fault is handled manually.

[0061] Step four: After any level of emergency response in step three above, the system will automatically return to step two and continue to monitor the safety index in real time, forming a continuous closed-loop monitoring and control cycle. Steps two to four will be repeated in each control cycle to ensure that the safety control of the laser show is always in an active and dynamic safety control state.

[0062] Within a given safety range, a three-tiered response system is implemented, comprising: no intervention, virtual channel constraint, and emergency stop. Virtual channel constraint dynamically generates a three-dimensional conical electronic channel with the current beam position and propagation direction as its axes, performing trajectory correction and power limiting. Emergency stop involves linearly decaying the power within a short time and guiding the beam to a safety absorption trap, which is then released after manual reset. The three-tiered response is based on a risk gradient, implementing gradual intervention from soft constraints to forced shutdown. The technical effect is that it can maintain performance continuity with minimal intrusive adjustments under moderate risk, and maximize audience and equipment safety with extremely short response times under extreme risk. The on-site execution data after each emergency response is continuously transmitted back and mapped to a digital twin, cyclically executing risk calculation and decision-making steps to form a continuous closed-loop control.

[0063] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0064] The preferred embodiments of the invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention.

Claims

1. A laser performance safety control method based on digital twins, characterized in that, Includes the following steps: Step 1: Establish a virtual model in the digital environment that is synchronized with the live laser show and use a unified time reference to map the execution data, status data and environmental data to the virtual model in real time; Step 2: Calculate energy risk factors, pattern dynamic risk factors, equipment status risk factors, and environmental disturbance factors based on the virtual model, and then weight and fuse them according to preset weights to obtain a real-time safety index. Step 3: Based on the real-time security index, trigger the virtual channel constraint strategy within the preset security range or trigger the emergency stop strategy when the index falls below the lower threshold. Step four: After any emergency response, return to step two to form a closed-loop monitoring and control system.

2. The laser performance safety control method based on digital twins according to claim 1, characterized in that, The execution data includes the actual output power of the laser emitter, the actual deflection angle of the galvanometer, and the command position of the galvanometer; the status data includes the cavity temperature of the laser emitter and the motor temperature of the galvanometer; the environmental data includes the wind speed, wind direction, and ambient temperature at the performance site.

3. The laser performance safety control method based on digital twins according to claim 2, characterized in that, Calculation of energy risk factors based on virtual models: The beam propagation distance is obtained by adding the fixed optical path length from the laser exit to the current scanning position to the distance from the current position of the beam to the nearest boundary of the audience area. Assuming the beam is an ideal Gaussian beam, the beam radius when it reaches the boundary of the audience area is calculated based on the beam propagation distance, the initial spot diameter at the laser exit, and the beam divergence angle. Then, the spot area of ​​the beam is calculated based on the spot radius. The irradiance when the beam reaches the boundary of the audience area is obtained by dividing the actual output power of the laser by the spot area. The maximum acceptable irradiance for the human eye under different conditions is obtained. The real-time exposure irradiance is compared with the maximum permissible irradiance, and a safety margin coefficient is introduced. The energy risk factor is obtained by calculating and analyzing the normalized ratio.

4. The laser performance safety control method based on digital twins according to claim 3, characterized in that, Calculation of pattern dynamic risk factors based on virtual model: Extract the control point data set to construct the desired motion trajectory of the virtual beam path; the control point data set includes a timestamp, X-axis command position, Y-axis command position, and laser modulation signal for each control point; perform real-time analysis on the currently executed performance pattern segment, extract the instantaneous scanning speed, path curvature, and scanning acceleration, and calculate the pattern dynamic risk factor using a formula.

5. The laser performance safety control method based on digital twin according to claim 4, characterized in that, Calculate equipment status risk factors based on virtual models: The equipment status risk consists of thermal load risk and tracking accuracy risk. The thermal load corresponding to the laser cavity temperature and galvanometer motor temperature is obtained by substituting them into the normalized ratio formula, and the largest value is selected as the thermal load risk factor. Extract the current position of the beam and calculate the distance between it and the corresponding expected position in the expected motion trajectory of the virtual beam path to obtain the real-time error. Quantify the tracking error using a normalized ratio formula to directly reflect the dynamic response performance of the device and obtain the tracking accuracy factor. According to the actual emphasis weight, a weight is assigned to the heat load risk factor and the tracking accuracy factor respectively. Then, the load risk factor and the tracking accuracy factor are linearly weighted and fused to obtain the equipment status risk factor based on the assigned weight.

6. The laser performance safety control method based on digital twins according to claim 5, characterized in that, The calculation of environmental disturbance factors based on virtual models includes: estimating the wind-induced angular offset by using the current wind speed and the angle between the wind direction and the structure's sensitive direction, and then calculating the environmental disturbance factor by using the normalized ratio formula.

7. The laser performance safety control method based on digital twins according to claim 6, characterized in that, Virtual channel constraints: Based on the current beam position and direction of motion, a virtual electronic channel is dynamically generated in virtual space. The virtual electronic channel is a three-dimensional cone-shaped region centered on the current beam position and with the beam propagation direction as its axis, with a cone angle α=θ. beam ·k channel , where k channel θ is the channel relaxation factor. beam The nominal safety envelope angle is obtained by summing the beam divergence angle, the tracking error reduction angle, the wind-induced angular offset, and the fixed safety margin angle. The tracking error reduction angle is obtained by dividing the real-time tracking error by the fixed optical path length from the laser exit to the current position of the beam. The boundary of the virtual electronic channel is defined as an absolutely forbidden safety boundary. The predicted beam path is obtained by extrapolating the velocity vector of the beam at the current position to the trajectory of a fixed future time. It is then determined whether the predicted beam path will exceed the range of the virtual electronic channel. If it is predicted that the beam will exceed the boundary of the virtual channel, a virtual channel warning is generated and active avoidance control is immediately initiated. The active avoidance control includes: sending a correction command to the galvanometer to adjust the beam direction and keep it in the center of the channel, and simultaneously sending a power limiting command to the laser controller to limit the output power to the current value Q1; where Q1 is a percentage, Q1∈(0,100%); if the virtual channel warning is triggered for three consecutive control cycles, the actual laser output power is automatically gradually reduced to Q2 until the risk is eliminated; where Q2 is a percentage, Q2∈(20%,80%).

8. The laser performance safety control method based on digital twins according to claim 9, characterized in that, Emergency stop strategy: Immediately send a power attenuation command to the laser emitter, controlling the laser to linearly attenuate its output power to a safe level within a fixed time period. The specific safe level of the output power is determined according to the Class 1 emission limit achievable for the corresponding laser wavelength λ in the IEC 60825-1 standard. Simultaneously, send a safe position command to the galvanometer, controlling the galvanometer to guide the beam towards a preset safe absorption trap within a limited time. The safe absorption trap is a completely enclosed area in the physical space with no audience and a high absorption rate. After the power attenuation is complete and the beam has been guided to a safe direction, send an emergency stop status signal to the backstage laser performance control staff.

9. A laser performance safety control system based on digital twins, characterized in that... The laser performance safety control method based on digital twins as described in any one of claims 1-8 includes: The digital modeling module creates a virtual model in the digital environment that is synchronized with the live laser show and uses a unified time reference to map execution data, status data and environmental data to the virtual model in real time. The real-time monitoring module calculates energy risk factors, pattern dynamic risk factors, equipment status risk factors, and environmental disturbance factors based on a virtual model, and then weights and fuses them according to preset weights to obtain a real-time safety index. The safety control module triggers a virtual channel constraint strategy within a preset safety range based on the real-time safety index, or triggers an emergency stop strategy when the value falls below the lower threshold. After any emergency response, it returns to the real-time monitoring module to form a closed-loop monitoring and control system.

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