High-cold tunnel snow-prevention shed lighting regulation method based on external visible conditions

Abstract

The application discloses a high-cold tunnel snow-preventing shed lighting regulation and control method based on external visible conditions, relates to the technical field of tunnel lighting control, and comprises the following steps: in order to realize snow-preventing shed lighting regulation and control, four types of optical environment parameters, i.e., external light intensity, visibility, snow reflectivity and solar altitude, are acquired, illumination change information corresponding to each parameter is uniformly mapped into a same time sequence in time sequence, and an external illumination change curve is generated. The application realizes dynamic synchronization and smooth transition of lighting brightness by establishing a time corresponding relationship between external illumination change and snow-preventing shed lighting brightness response. Brightness flicker is eliminated by early triggering and step-by-step regulation, and adaptive regulation is realized in combination with rolling correction, so that the snow-preventing shed lighting can be continuously stable under complex illumination conditions, and driving visual comfort and driving safety are improved.

Description

Technical Field

[0001] This invention relates to the field of tunnel lighting control technology, specifically to a method for controlling the lighting of snow shelters in high-altitude, cold-weather tunnels based on external visibility conditions. Background Technology

[0002] Lighting control for snow shelters in high-altitude, cold-weather tunnels, based on external visibility conditions, refers to a lighting control method that dynamically matches the brightness, distribution, and rhythm of lighting changes within the snow shelter during its operation. This method continuously senses external environmental brightness, visibility, snow reflection intensity, and diurnal variation characteristics to determine changes in external visual conditions in real time. Based on this, it synchronously adjusts the artificial lighting inside the shelter, ensuring a continuous and stable transition in visual brightness between the inside and outside of the snow shelter. This avoids visual adaptation difficulties for drivers caused by sudden changes in brightness or excessive contrast. Under typical high-altitude, cold-weather conditions such as snowfall, increased snow reflection, or rapid switching between strong and weak light, the lighting control process uses external visibility conditions as a reference point to dynamically correct the output level and distribution rhythm of the lighting inside the shelter, thereby maintaining visual continuity and driving safety when vehicles enter the snow shelter.

[0003] The existing technology has the following shortcomings:

[0004] In existing technologies, tunnel snow canopy lighting systems in high-altitude and cold regions typically rely on external brightness sensors to monitor ambient light intensity in real time and automatically adjust the illuminance inside the canopy through feedback. However, around sunset, the frequency band composition and intensity of light reflected from the snow surface change drastically, with spectral energy shifting rapidly within a short period. Existing lighting control feedback mechanisms suffer from response delays, causing periodic fluctuations in the system's output light intensity. These fluctuations manifest spatially as a periodic flickering phenomenon of alternating light and dark, forming a dynamic light domain change resembling a breathing rhythm. When vehicles travel at high speeds through such areas, the driver's visual system must constantly adapt to light and dark conditions in a short time, easily leading to visual fatigue and disorientation. If the flickering period is close to the vehicle's movement frequency, it can also cause visual positioning loss, making it impossible for the driver to accurately judge the tunnel's depth and the direction of entrances and exits, posing a significant driving safety hazard.

[0005] The information disclosed in the background section is only intended to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0006] The purpose of this invention is to provide a method for controlling the lighting of snow shelters in high-altitude, cold-weather tunnels based on external visibility conditions, so as to solve the problems mentioned in the background art.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a method for controlling the lighting of snow shelters in high-altitude, cold-weather tunnels based on external visibility conditions, comprising the following steps:

[0008] To achieve lighting control for snow shelters, four types of optical environment parameters are acquired: external light intensity, visibility, snow reflectivity, and solar altitude. The light change information corresponding to each parameter is mapped to the same time series in chronological order to generate an external light change curve for snow shelter lighting control.

[0009] Based on the analysis of the brightness response data of the snow shelter lighting system according to the external light change curve, the rate of change of external light is calculated, the time interval of the rate of change of external light exceeding the preset threshold is extracted, and the time period of lighting flicker risk is generated.

[0010] During periods of high risk of lighting flicker, the external light change curve and the snow shelter lighting brightness response curve are compared over time to identify sections where the two curves are inconsistent in their brightness change trends. These inconsistent sections are marked as lighting adjustment conflict points, and a list of lighting adjustment conflicts is generated.

[0011] The timing sequence of lighting control is adjusted according to the list of lighting adjustment conflicts. An illuminance adjustment command is set to be triggered in advance before the time interval corresponding to each lighting adjustment conflict point. The illuminance adjustment process is divided into multiple time-interval step-by-step adjustment stages to smooth illuminance changes.

[0012] Based on the lighting output results after time sequence adjustment, the gradual amplitude and rate of change of illuminance are set, the time correspondence between the external light change curve and the snow shelter lighting brightness response curve is continuously updated, and the lighting control time sequence is rolled to ensure that the changes in snow shelter lighting brightness and external light change are synchronized and transition continuously.

[0013] Preferably, the steps for generating the external light change curve are as follows:

[0014] For the external optical environment of the snow shelter, real-time change information of four types of optical environment parameters, namely, external light intensity, visibility, snow reflectivity and solar altitude, is obtained to reflect the characteristics of light change throughout the day, as well as air transparency, snow surface reflectivity and solar illumination angle.

[0015] After acquiring the four types of optical environment parameters, the external light intensity, visibility, snow reflectivity and solar altitude are uniformly aligned in the time dimension to establish a unified time reference. The change information of each parameter is rearranged according to the same time interval to form a continuous time series.

[0016] After completing the time reference alignment, the variation range of the four types of optical environment parameters was standardized, and the parameters were made comparable in the time dimension through proportional adjustment and physical quantity conversion.

[0017] The unified sequences of changes in external light intensity, visibility, snow reflectivity, and solar altitude are continuously connected in chronological order to generate an external light variation curve for controlling the lighting of snow shelters.

[0018] Preferably, in the process of generating the external light intensity variation curve, the time change record of external light intensity is used as the time line, and the changes in visibility, snow reflectivity and solar altitude are interpolated and adjusted in time so that each time point corresponds to the observation results of the four types of optical environment parameters, thereby ensuring the continuity of the external light intensity variation curve in the time dimension and the integrity of the data correspondence.

[0019] Preferably, the steps for generating the lighting flicker risk period are as follows:

[0020] After generating the external light change curve for snow shelter lighting control, the change trend of the external light change curve within a continuous time range is analyzed in segments, and the light intensity change amplitude and direction of each time period are extracted to identify the light rise interval, fall interval and fluctuation interval.

[0021] After completing the segmented analysis of the external light change trend, the brightness response data of the internal lighting of the snow shelter was obtained, and a time correspondence was established within the same time range so that each time point contains a synchronous record of the external light intensity and the brightness of the snow shelter lighting.

[0022] After obtaining the external light change curve and the brightness response data of the snow shelter lighting, the rate of change of external light is calculated, and the time periods of sudden increase and decrease in the rate of change of external light are identified through time scaling.

[0023] After completing the analysis of the rate of change of external light, a preset threshold is set to distinguish between stable and drastic light change states. The time intervals in which the rate of change of external light exceeds the preset threshold are arranged continuously to generate the lighting flicker risk period.

[0024] Preferably, the steps for generating the illumination adjustment conflict list are as follows:

[0025] After identifying the period of lighting flicker risk, the time interval of the external light change curve and the brightness response curve of the snow shelter lighting are divided and synchronized. Taking the start time of the lighting flicker risk period as the reference point, the lighting flicker risk period is divided into continuous sampling segments and a brightness change sequence under a unified time axis is established.

[0026] After aligning the time axis, the directional analysis and amplitude comparison of the brightness change trends of the external light change curve and the snow shelter lighting brightness response curve are performed. The light change direction, snow shelter brightness change direction and change amplitude differences of each sampling point are recorded to form a brightness trend comparison sequence.

[0027] After obtaining the brightness trend comparison sequence, identify the time segments where the two curves are inconsistent in brightness change trends, record the start and end time, duration and brightness difference of each inconsistent segment, and establish a brightness difference time distribution map.

[0028] The starting time point of each segment with inconsistent brightness change trends is marked as the lighting adjustment conflict point, and a lighting adjustment conflict list is generated according to the time sequence to guide the subsequent time adjustment of the snow shelter lighting control.

[0029] Preferably, when generating the list of lighting adjustment conflicts, the occurrence time, duration of the corresponding inconsistent section, peak brightness difference, rate of change of external light, and direction of change of brightness of the snow shelter lighting are recorded for each lighting adjustment conflict point. The conflict distribution is formed by arranging them in chronological order to determine the delay, advance, and fluctuation range of the lighting brightness response, so as to support the targeted optimization and adjustment of the subsequent lighting control time sequence.

[0030] Preferably, the lighting control time sequence is adjusted according to the lighting adjustment conflict list, and an illuminance adjustment command is set to be triggered in advance before the time interval corresponding to each lighting adjustment conflict point. The illuminance adjustment process is divided into step-by-step adjustment stages with continuous time intervals as follows:

[0031] After obtaining the list of light regulation conflicts, each light regulation conflict point in the list is analyzed to determine the time location and scope of influence of the light regulation conflict point. The conflict influence interval is delineated according to the characteristics of external light change, forming a continuous conflict interval sequence on the time axis.

[0032] After determining the light adjustment conflict points and their affected ranges, an illuminance adjustment command is set to be triggered in advance before the time interval corresponding to each light adjustment conflict point. Based on the start time of the light adjustment conflict point, the brightness of the snow shelter lighting is increased or decreased according to the direction of change of external light.

[0033] After setting the advance trigger illuminance adjustment command, the illuminance adjustment process is divided into multiple step-by-step adjustment stages with consecutive time intervals. Each step-by-step stage performs an illuminance fine-tuning operation to keep the illuminance change smooth and progressive over time.

[0034] After the step-by-step adjustment phase is completed, the timing sequence of lighting control is continuously updated. By adjusting the step-by-step adjustment time interval and direction, dynamic synchronization between changes in the brightness of the snow shelter lighting and changes in external light is achieved.

[0035] Preferably, based on the lighting output results after time-sequence adjustment, the gradual amplitude and rate of change of illuminance are set, the time correspondence between the external light change curve and the snow shelter lighting brightness response curve is continuously updated, and the lighting control time sequence is adjusted through a rolling correction method as follows:

[0036] After adjusting the lighting time sequence and obtaining new lighting output results, time series analysis was performed on the lighting output data. The illuminance change curve was divided into continuous sampling intervals, and the brightness value, rate of change and duration of the snow shelter lighting were extracted to determine the illuminance change pattern.

[0037] After clarifying the characteristics of the changes in the lighting output of the snow shelter, the gradual amplitude and rate of change of illuminance are set according to the trend of changes in external light. The direction and rate of change of external light are determined by comparing the time axis, so that the lighting brightness response keeps continuously corresponding to the external light.

[0038] After setting the illuminance change parameters, continuously update the time correspondence between the external light change curve and the snow shelter lighting brightness response curve, and correct the time deviation based on real-time light data to keep the illuminance change rhythm consistent.

[0039] Based on continuously updating the time correspondence, the lighting control time sequence is dynamically optimized by rolling correction. Through continuous time window monitoring and adjustment, the changes in the brightness of the snow shelter lighting are kept synchronized with the changes in external light in real time and with a smooth transition.

[0040] The technical effects and advantages provided by the present invention in the above technical solution are as follows:

[0041] This invention establishes a time-correlation relationship between the external light intensity curve and the brightness response of the snow shelter's lighting, enabling the internal lighting of the snow shelter to dynamically follow and continuously match changes in external light intensity. By triggering illuminance adjustment commands in advance during periods of rapid change in external light intensity and employing a step-by-step adjustment method to smooth the illuminance transition, the lighting system can complete its brightness response before sudden changes in external light intensity, fundamentally eliminating periodic brightness fluctuations and flickering. This method effectively improves the continuity of brightness transition between the inside and outside of the shelter, allowing drivers to maintain stable visual perception during high-speed driving, reducing visual fatigue and the risk of disorientation, and enhancing the safety and comfort of the snow shelter's traffic environment.

[0042] This invention enables adaptive lighting control by continuously and dynamically correcting the timing sequence of lighting adjustments. It automatically adjusts the amplitude and rate of change in illuminance based on the rate and direction of changes in external light. This method achieves real-time dynamic coordination of lighting brightness, ensuring that the snow canopy lighting remains synchronized with external visibility conditions under varying weather conditions, snow reflection intensity, and solar altitude. Through continuous correction and smooth control, illuminance changes are more stable and natural, avoiding sudden changes in light that could stimulate the driver's visual system and effectively ensuring visual continuity and driving safety during tunnel entry and exit. Attached Figure Description

[0043] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0044] Figure 1 This is a flowchart of the method for controlling the lighting of snow shelters in high-altitude, cold-weather tunnels based on external visibility conditions, according to the present invention. Detailed Implementation

[0045] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, they are provided so that the description of this disclosure will be more complete and fully convey the concept of the exemplary embodiments to those skilled in the art.

[0046] This invention provides, for example Figure 1 The lighting control method for snow shelters in high-altitude, cold-weather tunnels based on external visibility conditions, as shown, includes the following steps:

[0047] To achieve lighting control for snow shelters, four types of optical environment parameters are acquired: external light intensity, visibility, snow reflectivity, and solar altitude. The light change information corresponding to each parameter is mapped to the same time series in chronological order to generate an external light change curve for snow shelter lighting control.

[0048] To achieve controlled lighting for snow shelters, continuous observation and dynamic information integration of the external optical environment are conducted. This process involves uniformly time-series processing of four types of optical environment parameters: external light intensity, visibility, snow reflectivity, and solar altitude. This generates an external light variation curve for controlling the snow shelter lighting, providing a foundation for subsequent lighting brightness response analysis and time-series control. The specific implementation process is as follows:

[0049] To assess the characteristics of the external optical environment of the snow shelter, real-time changes in ambient light intensity, visibility, snow reflectivity, and solar altitude were acquired. Ambient light intensity characterizes the overall illuminance level of natural light, composed of skylight, direct sunlight, and light reflected from the snow surface. To reflect the characteristics of light variation throughout the day, continuous data collection is required, including the low light phase in the early morning, the high light phase at midday, and the low light phase at sunset. Visibility data reflects the attenuation of light propagation by suspended particulate matter, water vapor, ice crystals, or snow particles in the air; its changes directly affect light penetration and the visual clarity outside the snow shelter. Snow reflectivity reflects the proportion of incident light reflected by the snow layer on the ground or slope; its value is influenced by snow thickness, particle size, humidity, and surface cleanliness. Solar altitude characterizes the change in the sun's angle relative to the horizon; tracking the sun's altitude angle at different times of the day reflects the trends of day-night transition and changes in the direction of sunlight. By continuously recording the above four optical environment parameters, a multi-dimensional data set reflecting the external lighting conditions can be formed, providing accurate raw information on external lighting for the control of snow shelter lighting.

[0050] After acquiring data on ambient light intensity, visibility, snow reflectivity, and solar altitude, it is necessary to align these four optical environmental parameters across time. Since the acquisition time intervals, data update rates, and response delays of each parameter differ, directly using the raw data for analysis would lead to temporal shifts, affecting the continuity of ambient light variation trends. Therefore, a unified time reference is established on the timeline, rearranging the data recording points for the four optical environmental parameters according to the same time intervals, ensuring that each time point contains the corresponding values ​​for all four parameters. Specifically, the change in ambient light intensity is used as the main timeline, and based on this, the data on changes in visibility, snow reflectivity, and solar altitude are interpolated and adjusted over time, ensuring that each parameter has corresponding observation results at the same time point. By unifying the time reference, deviations caused by different parameter sampling frequencies and delays can be eliminated, maintaining consistency of the four optical environmental parameters across time and providing a precise temporal basis for subsequent integration of illumination variation trends.

[0051] After aligning the time references, to ensure the comparability of the four optical environment parameters—external light intensity, visibility, snow reflectivity, and solar altitude—it is necessary to standardize their numerical ranges. Because these four parameters have different physical dimensions, units, and value ranges, direct superposition analysis can lead to one parameter's variation dominating the overall trend while ignoring the influence of other parameters. To avoid this bias, the variation sequence of each parameter needs to be proportionally adjusted so that its variation trend within the same time range reflects its contribution to the external light conditions in a relative quantity. For example, the variation curve of external light intensity is mapped to a fixed interval through scaling to maintain the relative trend of overall light variation; the variation of visibility is represented as a change in light attenuation rate using the conversion relationship of light transmittance; the variation of snow reflectivity is converted into a light enhancement rate based on the degree of influence of snow layer brightness; and the variation of solar altitude is normalized using the correction relationship between the solar angle and incident light intensity. By standardizing the four optical environment parameters, their dimensional significance on the same time axis can be ensured without altering their original variation patterns. This facilitates the comprehensive superposition of these parameters to generate curves that reflect the true dynamics of illumination. This process guarantees the overall consistency of external illumination trends, ensuring that changes in each parameter have a corresponding impact on the overall illumination performance.

[0052] After standardization, the normalized sequences of external light intensity, visibility variation, snow reflectivity variation, and solar altitude variation are continuously connected in chronological order. With time as the horizontal axis and the overall light variation as the vertical axis, a complete external light variation curve is formed. This continuous connection does not mean simply splicing curves corresponding to different parameters end-to-end. Instead, it means synchronously combining the normalized results of each optical environment parameter at each time point under a unified time reference and arranging them in chronological order to form continuous time-series data.

[0053] Specifically, after establishing a unified timeline, the entire day is divided into several consecutive time sampling points. At each time sampling point, normalized values ​​of four optical environment parameters—external light intensity, visibility, snow reflectivity, and solar altitude—are acquired. Using the time sampling of external light intensity as the main timeline, at the same time point, the interpolated and aligned changes in visibility, snow reflectivity, and solar altitude are mapped one-to-one with the normalized value of external light intensity, forming a synchronous data set containing the four parameters. By arranging the data sets corresponding to each time sampling point sequentially in chronological order, continuous connection of the parameter change information is achieved, thereby constructing a continuous time series reflecting the changes in external light conditions over time.

[0054] Based on this, to obtain the comprehensive change in illumination for snow shelter lighting control, it is necessary to perform comprehensive calculations on the four normalized parameters at each time sampling point to obtain the comprehensive illumination value at that time point. In one embodiment, a weighted superposition method can be used to comprehensively process the parameters. That is, at each time point, the normalized external light intensity, visibility change value, snow reflectivity change value, and solar altitude change value are multiplied by their respective weighting coefficients and then summed to obtain the comprehensive illumination value at that time point. The weighting coefficients can be preset or calibrated according to the illumination characteristics of high-altitude and cold regions or historical operating data. In another preferred embodiment, the normalized parameters can also be comprehensively calculated using a function synthesis method based on the characteristics of light propagation and reflection. For example, visibility change can be used as a light attenuation factor, snow reflectivity change as a light enhancement factor, and solar altitude change as an incident angle correction factor, which are then used together with the normalized value of external light intensity to calculate the comprehensive illumination value.

[0055] By calculating the comprehensive illumination values ​​at continuous time sampling points and connecting these values ​​sequentially along the x-axis (time) and y-axis (comprehensive illumination value), a complete external illumination variation curve is formed. This curve continuously reflects the comprehensive changes in external illumination at different times, accurately representing the combined impact of external illumination intensity, visibility, snow reflectivity, and solar altitude changes on the lighting environment. This serves as the foundational input for subsequent analysis of the snow shelter's lighting brightness response, calculation of the rate of change in external illumination, and optimization of lighting control timing. The curve reflects the dynamic characteristics of external illumination under different weather conditions and throughout the day. As the solar altitude gradually increases, the curve shows a gradual increase in overall brightness; as the sun approaches the horizon, the curve declines, indicating a gradual weakening of illumination; when snow reflectivity increases, the curve exhibits local brightness peaks during the corresponding time period; and when visibility decreases, the brightness distribution of the curve decays within a short period. Through continuous recording and connection, a complete time-series curve can be formed, accurately reflecting the comprehensive changes in external illumination. This curve not only includes the direct trend of natural light intensity changes, but also comprehensively reflects the impact of visibility changes on light propagation paths, the contribution of snow reflection characteristics to light enhancement, and the coupling effect of solar altitude changes on light direction and intensity. By integrating these multi-dimensional features over time, the external light variation curve can serve as the core basis for controlling the lighting of snow shelters, providing continuous, complete, and traceable external visual condition input for subsequent lighting brightness response analysis, light fluctuation risk identification, and illuminance time adjustment.

[0056] Based on the analysis of the brightness response data of the snow shelter lighting system according to the external light change curve, the rate of change of external light is calculated, the time interval of the rate of change of external light exceeding the preset threshold is extracted, and the time period of lighting flicker risk is generated.

[0057] After generating the ambient light variation curve for snow shelter lighting control, it is necessary to jointly analyze the ambient light variation curve and the brightness response data of the snow shelter lighting to identify periods of rapid ambient light change and generate periods of lighting flicker risk, providing a basis for optimizing the timing of subsequent illuminance adjustments. The specific steps are as follows:

[0058] After obtaining the external light intensity variation curve, the trend of this curve over a continuous time range is analyzed in segments to determine the direction and magnitude of change in external light intensity in different time periods. Specifically, using the time axis of the external light intensity variation curve as a reference, the entire day's light intensity variation is divided into multiple adjacent time periods, and the amplitude and direction of light intensity variation in each time period are extracted segment by segment. The variation of external light intensity is mainly affected by the combined influence of solar altitude, cloud thickness, air transparency, and the reflectivity of snow cover in the natural environment. During periods when the sun is at its highest, the external light intensity variation curve typically shows an increasing trend in brightness; during periods when the sun is gradually setting, the curve shows a decreasing trend in brightness; when clouds are dense or visibility decreases, the curve shows light attenuation in local areas; when snow reflection is enhanced or sunlight briefly penetrates the cloud layer, the curve shows a peak of light intensity enhancement. By identifying these trends segment by segment along the time axis, the distribution of the rising, falling, and fluctuating ranges of external light intensity can be obtained, providing a basis for subsequent calculation of the rate of change. The key to this process is to ensure the continuity of the external light change curve, so that the light change information of each time period can be completely preserved without time gaps or data jumps.

[0059] To achieve a correlation analysis between changes in external light intensity and the lighting brightness response of the snow shelter, it is necessary to collect lighting brightness response data inside the snow shelter within the same time frame. The lighting brightness response curve of the snow shelter represents the actual response result of the internal lighting brightness over time when the snow shelter lighting system adjusts to changes in external light intensity according to lighting control commands during operation.

[0060] In practical implementation, illuminance sensors are installed along the driving direction inside the snow shelter to continuously sample the illuminance values ​​of the illuminated areas inside the snow shelter; alternatively, the actual output illuminance parameters of each lighting fixture are directly acquired through the snow shelter lighting control system as response data for the internal lighting brightness of the snow shelter. The aforementioned illuminance sensors or lighting control systems can be implemented using conventional brightness detection and data acquisition methods in this field.

[0061] When collecting data on the brightness response of the interior lighting of the snow shelter, the sampling time reference is consistent with the time reference used for the external light change curve. That is, the brightness of the interior lighting of the snow shelter is recorded under the same time coordinate, ensuring that at each sampling time point, both the external light change data and the snow shelter lighting brightness data corresponding to that time point can be obtained. The sampling period can be set according to the response characteristics of the lighting control system and the rate of change of external light to ensure the continuity of the brightness change process and the time resolution.

[0062] The collected data on the internal lighting brightness of the snow shelter were arranged chronologically to form a continuous time series. This series was then plotted with time on the horizontal axis and lighting brightness on the vertical axis, resulting in a snow shelter lighting brightness response curve that reflects the actual response of the snow shelter lighting system to changes in external light intensity. This curve accurately reflects the brightness change trend of the snow shelter lighting under the control strategy, including brightness increases, decreases, and stable changes.

[0063] By aligning and comparing the brightness response curve of the snow shelter lighting with the external light change curve on a unified time axis, we can analyze whether there are time delays, mismatched change rates, or brightness fluctuations in the response of the snow shelter lighting brightness to changes in external light. This provides a reliable data foundation for subsequent identification of lighting flicker risk periods, determination of lighting adjustment conflict points, and adjustment of the lighting control time sequence. This brightness response data reflects the actual brightness adjustment results of the snow shelter lighting as external light changes. Since snow shelter lighting is significantly affected by temperature when operating in high-altitude and cold regions, the light source start-up speed, brightness rise rate, and lighting control signal transmission delay can all lead to response lags. Therefore, when collecting lighting brightness response data, the time sampling should be consistent with the external light change curve to ensure that both have the same time resolution. In specific implementation, sampling points that perfectly match the time labels of the external light change curve are selected, and the brightness values ​​of the internal lighting of the snow shelter are arranged in chronological order to form a continuous response sequence. This time-correlation mechanism allows for the synchronous recording of external light intensity and internal lighting brightness within the snow shelter at every point in time, providing a continuous data foundation for subsequent calculations of the rate of change in external light intensity and analysis of brightness response characteristics. In this way, the dynamic differences between the snow shelter's lighting brightness and changes in external light intensity can be visually observed, revealing any delays, over-adjustments, or failures in the lighting brightness response to keep pace with changes in external light intensity.

[0064] After obtaining the external light intensity variation curve and the illumination response data of the snow shelter, it is necessary to calculate and analyze the rate of change of external light intensity to determine the severity of the change. The rate of change of external light intensity represents the speed at which light intensity changes per unit time, and its magnitude directly reflects the speed of change in the lighting environment. In high-altitude and cold regions, changes in external light intensity exhibit sudden and periodic characteristics. For example, when the sun's altitude rises or falls rapidly, light intensity changes significantly in a short period of time; when thick clouds suddenly break or reflection intensifies after snowfall stops, light intensity also experiences short-term, dramatic fluctuations. To fully understand these characteristics, it is necessary to conduct continuous analysis of adjacent time points in the external light intensity variation curve. By comparing the trends of adjacent light intensity changes in the time series, the speed and direction of light intensity changes can be intuitively determined. In practice, light intensity changes are divided into three types: a continuously rising region, a continuously falling region, and a fluctuating region. The amplitude of change in each segment is then proportionalized over time, allowing the speed of light intensity changes to be quantified in a continuous manner over time. After segmenting the continuous time range of the external light change curve, it is necessary to perform time scaling on the light change amplitude within each segment in order to accurately reflect the speed of external light change.

[0065] Specifically, for any segment of illumination change, the total amplitude of the external illumination change within that segment and the corresponding duration are first determined. The total amplitude of illumination change characterizes the overall change in light intensity within the segment, while the duration characterizes the length of the change process on the time axis. Subsequently, the total amplitude of illumination change is proportional to the duration of the segment. By calculating the ratio of the total amplitude of illumination change to the duration, the amount of illumination change per unit time is obtained, which is taken as the rate of change of external illumination for that segment.

[0066] By performing the aforementioned time-proportioning process, light change segments of different durations can be uniformly converted into a change description based on unit time, thereby eliminating the influence of segment length differences on the judgment of light change and making the intensity of light change in each segment comparable on a time scale. Based on this external light change rate, segments with relatively gentle external light changes and segments with sudden increases or decreases in the rate of external light change can be accurately identified, providing a quantitative basis for subsequent judgments on whether light changes exceed preset thresholds and for further generating risk periods of lighting flicker. Through this processing method, time periods with sudden increases in the rate of external light change can be identified, i.e., the period when external light intensity rapidly jumps from low to high, and time periods with sudden decreases in the rate of external light change, i.e., the period when light intensity rapidly decreases from high to low. These time periods usually correspond to stages of unstable light changes and are also potential risk areas for brightness flicker in snow shelter lighting control.

[0067] After analyzing the rate of change in external light intensity, to identify time intervals where the rate of change exceeds safe limits, a preset threshold needs to be set to distinguish between stable and drastic light intensity changes. This threshold is determined comprehensively based on the typical light intensity change characteristics of high-altitude and cold regions and the ability to adjust the lighting brightness of snow shelters. In practice, firstly, based on historical monitoring data or real-time data, the rate of change of external light intensity in high-altitude and cold regions over a continuous time range is statistically analyzed to obtain typical distribution characteristics of the rate of change. This rate of change distribution reflects the normal range of light intensity changes in high-altitude and cold regions over different time periods, as well as sudden changes caused by factors such as rapid changes in solar altitude, changes in cloud cover, or increased snow reflection, thus providing a basis for identifying drastic changes in external light intensity.

[0068] Simultaneously, parameters of the snow shelter lighting system's brightness adjustment capability under current operating conditions are obtained, including the light source start-up response time, the maximum achievable rate of increase or decrease in illuminance, and the transmission delay of the lighting control signal. These parameters collectively define the range of brightness changes that the snow shelter lighting can stably achieve per unit time, reflecting the actual response capability of the lighting system to changes in external light.

[0069] Based on this, the rate of change in external light intensity is compared and analyzed with the brightness adjustment capability of the snow shelter lighting system. When the rate of change in external light intensity exceeds the stable brightness change rate that the snow shelter lighting system can achieve per unit time, or approaches a preset proportion of that brightness change rate, the corresponding rate of change in external light intensity is determined as the threshold for identifying periods of lighting flicker risk. This threshold setting effectively distinguishes between stable and drastic changes in external light intensity, ensuring that the identified time interval accurately reflects potential risk periods where the snow shelter lighting may struggle to maintain synchronized response.

[0070] By setting the thresholds as described above, when the rate of change in external light exceeds the threshold, it indicates that the external light is changing rapidly within a short period of time, and there is a risk of lag or uneven transition in the brightness response of the snow shelter lighting. Therefore, the corresponding time interval is identified as a period of lighting flicker risk. This comprehensive method of determining the thresholds provides a clear technical basis and feasibility for identifying lighting flicker risks, and provides reliable triggering conditions for optimizing the subsequent illuminance adjustment time sequence.

[0071] By comparing the rate of change in ambient light with this threshold, the time intervals in which the rate of change in ambient light exceeds the preset threshold can be clearly defined. Each time interval represents a stage in which ambient light undergoes drastic changes in a short period of time, such as the brightness decrease caused by rapid changes in the sun's altitude angle before and after sunset, or the brightness surge caused by increased snow reflection after a blizzard dissipates. Within these time intervals, the rate of change in ambient light is too rapid, making it difficult to adjust the brightness response of the snow shelter lighting in a timely manner, which easily leads to brightness fluctuations. To facilitate the subsequent execution of snow shelter lighting control, these time intervals in which the rate of change in ambient light exceeds the threshold need to be arranged continuously in chronological order to form lighting flicker risk periods. The lighting flicker risk periods record the temporal information of the excessively rapid rate of change in ambient light, providing a time reference for early response to subsequent illuminance adjustments. In this way, the risk of sudden changes in light can be identified and actively avoided in advance during the snow shelter lighting control process, making the brightness adjustment of the snow shelter lighting more stable and smooth, and avoiding visual adaptation delays for drivers when passing through snow shelters due to sudden brightness changes.

[0072] During periods of high risk of lighting flicker, the external light change curve and the snow shelter lighting brightness response curve are compared over time to identify sections where the two curves are inconsistent in their brightness change trends. These inconsistent sections are marked as lighting adjustment conflict points, and a list of lighting adjustment conflicts is generated.

[0073] After identifying the periods of risk for lighting flicker, a precise time-axis comparison needs to be performed on the external light change curve and the snow shelter lighting brightness response curve within those periods to determine the differences in brightness change trends between the two curves. By continuously identifying the areas of difference, inconsistent segments are determined and marked as lighting adjustment conflict points. A lighting adjustment conflict list is then generated to guide subsequent time-based optimization and smoothing of lighting control. The specific steps are as follows:

[0074] After identifying the period of potential lighting flicker risk, it is necessary to divide the time intervals and synchronize the external light intensity change curve and the snow shelter lighting brightness response curve within that period. Since the external light intensity change curve reflects the continuous changes in the natural light environment, while the snow shelter lighting brightness response curve reflects the dynamic adjustment process of artificial lighting under control strategies, the two often exhibit response lag and asynchronous change rates. To achieve accurate comparison, the two curves need to be time-sampled and matched using the same time reference. In practice, using the start time of the potential lighting flicker risk period as a reference point, the period is divided into continuous sampling segments at fixed time intervals. Each sampling segment includes both the external light intensity value and the snow shelter lighting brightness value. Within each sampling segment, brightness data at the same time point is extracted from both curves, and a one-to-one correspondence is established, thus forming a brightness change sequence under a unified time axis. This method eliminates time offsets caused by different sampling intervals, signal delays, or response inertia, ensuring precise time synchronization between the external light intensity change curve and the snow shelter lighting brightness response curve within the potential lighting flicker risk period, providing a continuous and corresponding time series basis for subsequent trend analysis.

[0075] After aligning the time axis, the directional and amplitude comparisons of the brightness change trends of the external light change curve and the snow shelter lighting brightness response curve during the period of lighting flicker risk are performed. The brightness change trend describes the direction and rate of change of light over a continuous period, including three types: upward trend, downward trend, and stable trend. To determine the consistency of the two curves in their brightness change trends, it is necessary to analyze the direction of brightness change between adjacent sampling points along the time axis. When the external light change curve shows an increase in brightness over a certain period, while the snow shelter lighting brightness response curve shows a decrease in brightness over the same period, it indicates an inverse difference in the direction of change between the two curves. Similarly, when the external light change curve shows a decrease in brightness while the snow shelter lighting brightness continues to increase, this also constitutes an inconsistency in trends. Furthermore, when the two curves have the same direction of change but a large difference in the amplitude of brightness change—that is, the rate of change of external light is faster than the rate of change of the snow shelter brightness response, or the change of snow shelter brightness precedes the change of external light—it will also lead to a visual asynchrony in brightness. During this process, it is necessary to record the direction of change in external light intensity, the direction of change in brightness of the snow shelter lighting, and the difference in the magnitude of change between the two corresponding to each sampling point, forming a brightness trend comparison sequence. This sequence reflects the degree of coordination between the changes of the two curves during the period of lighting flicker risk and is the core basis for subsequent identification of inconsistent sections.

[0076] After obtaining the brightness trend comparison sequence, it is necessary to identify time segments where the brightness change trends of the external illumination change curve and the snow shelter lighting brightness response curve are inconsistent. To achieve this, continuous time sampling points within the lighting flicker risk period need to be analyzed segment by segment. When the external illumination change curve and the snow shelter lighting brightness response curve begin to show opposite directions of change or a continuously increasing difference in the magnitude of change at a certain time point, this time point is recorded as the start time of the inconsistent brightness change trend segment; when the two curves return to the same direction of change or the difference in the magnitude of change returns to within a preset range, this time point is recorded as the end time of the inconsistent segment. By continuously scanning the entire lighting flicker risk period, several inconsistent brightness change trend segments can be obtained. Each inconsistent segment corresponds to the dynamic mismatch state between the external illumination change and the snow shelter lighting response. To accurately describe the characteristics of the inconsistent segments, the duration, start and end times, maximum brightness difference, and deviation of the direction of change of each inconsistent segment need to be recorded. These records allow us to establish a time-varying spectrum of the difference between changes in external light intensity and the brightness response of the snow shelter lighting, clarifying the temporal distribution patterns and intensity of asynchronous phenomena.

[0077] After identifying and recording all inconsistent brightness variation trends, the starting time of each inconsistent segment needs to be marked as a lighting adjustment conflict point, and a lighting adjustment conflict list needs to be generated in chronological order. The lighting adjustment conflict point represents the moment when the snow shelter lighting control begins to decouple from changes in external light, and is a key node in the lighting control sequence that requires priority adjustment. When generating the lighting adjustment conflict list, each conflict point needs to be clearly identified, recording its occurrence time, the duration of the corresponding inconsistent segment, the peak brightness difference, the rate of change in external light, and the direction of change in the snow shelter lighting brightness. By chronologically sorting all the lighting adjustment conflict points, a complete lighting adjustment conflict list can be formed, reflecting the distribution characteristics of the asynchronous nature of snow shelter lighting control and changes in external light during periods of lighting flicker risk. The list of lighting adjustment conflicts provides a basis for subsequent lighting control. By analyzing the distribution pattern of lighting adjustment conflict points, the specific time periods in which the brightness response of the snow shelter lighting is delayed, advanced, or fluctuates can be identified. In the subsequent time sequence adjustment process, the lighting control strategy can be optimized in a targeted manner to make the brightness change inside the snow shelter smoother and reduce the visual discomfort caused by sudden changes in external light.

[0078] The timing sequence of lighting control is adjusted according to the list of lighting adjustment conflicts. An illuminance adjustment command is set to be triggered in advance before the time interval corresponding to each lighting adjustment conflict point. The illuminance adjustment process is divided into multiple time-interval step-by-step adjustment stages to smooth illuminance changes.

[0079] After obtaining the list of lighting conflict points, to ensure that the internal lighting brightness of the snow shelter continuously matches changes in external light over time, the timing sequence of lighting control needs to be adjusted according to the list. By triggering illuminance adjustment commands in advance before each lighting conflict point and dividing the illuminance change process into multiple consecutive time-step stages, a smooth transition of illuminance changes is achieved, making the lighting control process more stable and predictable. The specific steps are as follows:

[0080] After obtaining the list of lighting adjustment conflicts, each conflict point in the list is analyzed item by item to clarify its temporal location and scope of influence. The list records the occurrence time, duration, brightness difference magnitude, direction of external light change, and direction of the snow shelter lighting brightness response for each conflict point. By analyzing this information, the start and end positions of the conflict points on the timeline can be determined. To ensure the accuracy of the time sequence adjustment, the conflict influence interval needs to be defined based on the characteristics of external light change before and after the conflict point. This influence interval typically includes consecutive time periods in both directions before and after the conflict point, and its length depends on the rate of change of external light and the response delay time of the snow shelter lighting. By defining the influence interval for each conflict point, a continuous sequence of conflict intervals can be formed on the timeline for subsequent time sequence adjustments. At this point, each conflict interval corresponds to a lighting period that requires an earlier response or a later adjustment. By analyzing the list of lighting adjustment conflicts and establishing the conflict time distribution, a precise starting point and target range can be provided for the timing adjustment of lighting control, ensuring that subsequent lighting adjustment operations are implemented within the correct time window.

[0081] After identifying the points of conflict in illumination adjustment and their affected ranges, it is necessary to set an advance-triggered illuminance adjustment command before the time interval corresponding to each conflict point. The core purpose of advance triggering is to ensure that the response of the snow shelter lighting precedes the arrival of sudden changes in external light, thereby compensating for the brightness asynchrony caused by light source inertia, control signal transmission delay, and environmental feedback lag. In specific implementation, the illuminance adjustment start time is set according to a predetermined advance time interval, based on the start time of the illumination conflict point. The setting of the advance time interval needs to comprehensively consider the rate of change of external light, the response time of the snow shelter light source, and the direction of light change. The advance time interval is used to ensure that the brightness adjustment action of the snow shelter lighting occurs before the sudden change in external light, thereby offsetting the brightness asynchrony caused by light source response inertia and control delay. Therefore, the advance time interval is determined by comprehensively considering the rate of change of external light, the response time of the snow shelter light source, and the direction of light change.

[0082] Specifically, the response time of the snow shelter light source characterizes the time required for the snow shelter lighting system to go from receiving an illuminance adjustment command to the actual brightness change and reaching a stable state. This response time includes the control signal transmission delay, the light source start-up time, and the brightness stabilization time, and is an inherent characteristic of the snow shelter lighting system. The advance time interval uses this light source response time as the base time value to ensure that the lighting adjustment has a basic lead time.

[0083] Based on this, the advance time interval is adjusted according to the rate of change of external light intensity. The rate of change of external light intensity reflects how quickly the intensity of external light changes per unit time. When the rate of change of external light intensity is large, and the light intensity increases or decreases rapidly in a short period of time, in order to avoid sudden changes in brightness due to response lag in the snow shelter lighting, the advance time interval needs to be appropriately increased based on the light source response time. When the rate of change of external light intensity is small, and the light intensity changes relatively slowly, the advance time interval can be close to or equal to the light source response time to avoid premature adjustments that would result in unnatural lighting changes.

[0084] Simultaneously, the advance time interval is directionally adjusted based on the direction of change in external light. When the direction of change in external light is a rapid decrease in brightness, the advance time interval is relatively increased to prevent insufficient illumination or visual blackening inside the snow shelter, allowing the snow shelter lighting to start the brightness enhancement process earlier. When the direction of change in external light is a rapid increase in brightness, the advance time interval is relatively decreased to avoid excessively high illumination inside the snow shelter and the resulting contrast between light and dark, making the brightness reduction process more gradual.

[0085] Therefore, the advance time interval is determined by using the response time of the snow shelter's light source as a base value, adjusting the amplitude according to the rate of change in external light intensity, and making directional corrections based on the direction of light change. Those skilled in the art can reasonably set the advance time interval based on the response characteristics of the snow shelter lighting system and changes in external light intensity, thereby achieving a smooth transition and time synchronization of brightness changes during the snow shelter lighting control process. When external light intensity shows a rapid increase in brightness within the conflict zone, the advance-triggered illuminance adjustment command should control the snow shelter lighting to gradually reduce its intensity to prevent internal illuminance from exceeding external brightness and causing a significant contrast between light and dark. When the direction of external light intensity change is a rapid decrease in brightness, the advance-triggered illuminance adjustment command should control the snow shelter lighting to gradually increase its intensity to compensate for the visual blackening risk caused by the decrease in external brightness. The advance triggering time is generally selected within a continuous time period before the light adjustment conflict point occurs, allowing the illuminance adjustment process to proceed smoothly before a sudden change in external light intensity. Through the advance triggering mechanism, the snow shelter lighting can proactively respond before the light change produces a strong visual impact, establishing a time-forward relationship between external light changes and internal illuminance adjustments.

[0086] After triggering the illuminance adjustment command in advance, to avoid visual abrupt changes caused by rapid illuminance variations, the illuminance adjustment process needs to be divided into multiple consecutive step-by-step adjustment stages with consecutive time intervals. Each step-by-step adjustment stage is temporally adjacent and maintains a smooth progression in illuminance change. To achieve gradual illuminance change, the entire time period from the start of the illuminance adjustment to the arrival of the target illuminance should be divided into several sub-stages of equal length, with each sub-stage performing a fine-tuning operation. The magnitude of the illuminance adjustment should be allocated according to the rate of change in ambient light. When ambient light changes drastically, the number of step-by-step adjustment stages should be relatively large to ensure more subtle illuminance changes; when ambient light changes slowly, the number of step-by-step stages can be reduced accordingly to maintain the naturalness of the adjustment process. Within each step-by-step adjustment stage, the magnitude of the illuminance adjustment remains consistent or varies slightly, so that the lighting brightness change curve presents a smooth gradient on the time axis. When the brightness of the snow shelter lighting needs to be increased, the illuminance value in each step is slightly higher than the previous step; conversely, when the brightness needs to be decreased, the illuminance value in each step is slightly lower than the previous step. This step-by-step adjustment ensures that the change in illuminance is not an instantaneous jump but a continuous progression, thereby reducing the instantaneous burden on the driver's visual system and ensuring a natural transition in brightness between the inside and outside of the snow shelter. The execution time of the step-by-step adjustment should cover the entire conflict-affected area, ensuring that the illuminance inside the snow shelter can be smoothly adjusted before the change in external lighting is complete.

[0087] After the step-by-step adjustment phase is completed, the timing sequence of lighting control needs to be continuously updated to ensure that changes in the brightness of the snow shelter lighting are dynamically synchronized with changes in external light intensity over time. After adjusting the lighting control timing sequence according to the light adjustment conflict list, and executing the pre-triggered illuminance adjustment commands and step-by-step illuminance adjustment operations, the snow shelter lighting system establishes corresponding illuminance output states at each time point. These illuminance output states reflect the actual brightness response of the snow shelter lighting over time under the aforementioned timing sequence adjustment and smooth step-by-step adjustment. The above illuminance output states record the changes in the brightness of the snow shelter lighting over a continuous time axis in a time series format, constituting the lighting output results.

[0088] The lighting output results are derived from the actual execution results of the snow shelter lighting control system in response to the pre-triggered illuminance adjustment command and the step-by-step adjustment phase. These results include the illuminance values, illuminance change direction, and rate of change of the snow shelter lighting at different time points. Analyzing these lighting output results provides a clear picture of the snow shelter lighting's response to changes in external light during the previous stage of control, offering fundamental data support for further optimization of subsequent illuminance change parameters.

[0089] Based on the lighting output results after time-sequence adjustment, the gradual amplitude and rate of change of illuminance are set, and the time correspondence between the external light change curve and the snow shelter lighting brightness response curve is continuously updated. The lighting control time sequence is then continuously corrected to ensure that the changes in snow shelter lighting brightness and external light change are synchronized and transition continuously. Since changes in external light in high-altitude and cold regions are influenced by factors such as cloud density, snow reflection, solar altitude, and visibility, their rhythm is uncertain. Therefore, the time sequence adjustment should have real-time correction capabilities. During implementation, the lighting adjustment time interval and trigger time are fine-tuned by continuously observing the changing trends of the external light change curve and the internal lighting brightness curve of the snow shelter. When the rate of change of external light accelerates, the time interval between adjacent step-by-step adjustment stages is shortened to make the snow shelter lighting adjustment more sensitive; when the rate of change of external light slows down, the time interval between step-by-step adjustment stages is extended to keep the illuminance change of the snow shelter gradual. If the direction of change of external light is reversed during the adjustment process, such as from brightness increase to brightness decrease, the adjustment direction is immediately redefined, and the execution sequence of the step-by-step adjustment stages is recalculated. This continuous rolling time correction method ensures that the adjustment process of the snow shelter lighting always follows the real-time changes in the rhythm of external light, thereby achieving continuous illuminance output. This process ensures that the brightness of the snow shelter lighting remains synchronized with the external light throughout the entire operation cycle of the high-altitude tunnel, and will not cause sudden jumps in illuminance due to sudden changes in external light or feedback delays.

[0090] Based on the lighting output results after time sequence adjustment, the gradual amplitude and rate of change of illuminance are set, the time correspondence between the external light change curve and the snow shelter lighting brightness response curve is continuously updated, and the lighting control time sequence is rolled to ensure that the changes in snow shelter lighting brightness and external light change are synchronized and transition continuously.

[0091] After adjusting the lighting time sequence and smoothing the step-by-step illuminance adjustment, to further ensure that the internal lighting brightness of the snow shelter remains continuously synchronized with changes in external light and achieves a continuous transition over time, it is necessary to further refine the control of the illuminance change process based on the lighting output results adjusted in the previous stage. This is achieved by setting the gradual amplitude and rate of increase / decrease of illuminance changes, and continuously updating the time correspondence between the two in conjunction with the trend of external light changes. The lighting control time sequence is dynamically optimized using a rolling correction method, ensuring that changes in the snow shelter's lighting brightness remain consistent with changes in external light over time. The specific steps are as follows:

[0092] After adjusting the lighting time sequence and obtaining new lighting output results, a detailed time series analysis is needed to determine the actual variation pattern of the brightness inside the snow shelter's lighting in different time periods. The lighting output results record the trend of illuminance changes over time, including three types: brightness increase phase, stable phase, and decrease phase. To achieve smooth control of illuminance changes, the lighting output data needs to be extracted segment by segment, dividing the illuminance change curve into continuous sampling intervals on the time axis. Within each sampling interval, the brightness value, rate of change, and duration of the snow shelter lighting are recorded. These data can intuitively reflect the brightness adjustment status of the snow shelter lighting within a specific time period. For example, in the sampling interval near the entrance of the snow shelter, the lighting output usually shows an increasing trend; in the lighting area of ​​the middle section of the shelter, the illuminance change tends to be stable; in the exit section of the snow shelter, the illuminance generally gradually decreases as the external brightness increases. Through this segmented analysis method, the illuminance change pattern of the snow shelter's internal lighting in different time periods can be obtained, thus providing basic data for determining the amplitude and rate of change of illuminance. This analysis process ensures that lighting control can accurately identify its own brightness adjustment status under different external light conditions, providing a clear reference for subsequent dynamic adjustments.

[0093] After clarifying the actual variation characteristics of the snow shelter lighting output, it is necessary to set the gradation amplitude and rise / fall rate of illuminance change according to the trend of external light changes. The illuminance gradation amplitude reflects the amount of brightness change of the snow shelter lighting per unit time, while the rise / fall rate reflects the speed of illuminance change over time. Both together determine the smoothness and responsiveness of the lighting control. During implementation, the external light change curve and the snow shelter lighting output curve are compared point by point on the time axis to determine the direction and rate of change of external light. When external light increases rapidly in a short period of time, to prevent the brightness inside the snow shelter from lagging and causing a contrast between light and dark, the illuminance gradation amplitude should be reduced and the illuminance fall rate increased to quickly reduce the brightness of the snow shelter lighting. When external light decreases rapidly, to avoid visual dark adaptation difficulties inside the snow shelter, the illuminance gradation amplitude should be appropriately increased and the illuminance rise rate decreased to ensure a smooth increase in brightness. If the external light changes slowly, both the illuminance gradation amplitude and rise / fall rate should be kept at small values ​​to make the change process of the snow shelter lighting more natural. In this way, the response speed of lighting control can be matched with the rate of change of external light, ensuring that illuminance adjustment can react quickly without abrupt changes. Each setting of illuminance gradient parameters is based on the real-time state of the trend of external light change, thus ensuring that the brightness change of the snow shelter lighting always maintains a continuous temporal correspondence with the external light.

[0094] After setting the gradual amplitude and rate of change of illuminance, it is necessary to continuously update the time correspondence between the external light change curve and the snow shelter lighting brightness response curve. Because external light conditions in high-altitude and cold regions are affected by changes in solar angle, cloud cover, snow surface reflection, and atmospheric transparency, the external light change curve will continuously shift over time. If the time correspondence remains fixed, the snow shelter lighting brightness response will gradually deviate from the actual changes in external light. To avoid this time drift, new external light data needs to be continuously collected during the lighting control operation, and the outdated parts of the original curve need to be replaced with real-time data to form the latest external light change curve. Subsequently, the updated external light change curve and the current snow shelter lighting brightness response curve are analyzed for time correspondence, calculating the brightness difference and direction of change at each time point. When a time deviation is found between the two curves, i.e., the external light change is earlier or later than the snow shelter lighting response, the lighting control time parameters need to be fine-tuned. Specifically, when the peak brightness of the external light intensity curve appears before the lighting response curve, the trigger time for controlling the snow shelter lighting should be advanced; when the peak brightness of the external light intensity appears after the lighting response curve, the trigger time for lighting adjustment should be appropriately delayed. Through continuous updating of this time correspondence, it can be ensured that the snow shelter lighting response remains synchronized with the external light intensity, keeping the rhythm of illuminance changes consistent with the rhythm of changes in the external environment, and preventing illuminance imbalance caused by time drift.

[0095] Based on continuously updating the time correspondence, the timing sequence of lighting control needs to be dynamically optimized using a rolling correction method to ensure that changes in the brightness of the snow shelter lighting are synchronized in real time with changes in external light. Rolling correction is a continuous process of adjusting the timing sequence. Its core lies in continuously monitoring the trend of changes in external light during lighting control operation and dynamically optimizing the triggering timing of lighting adjustment commands based on new time deviation information. In specific implementation, the time axis is divided into continuous rolling windows, each covering a certain time range, using the lighting control time series as a benchmark. At the end of each rolling window, the system compares the difference between the current external light change curve and the snow shelter lighting brightness response curve, and readjusts the lighting control plan for the next time window based on the deviation. When the rate of change in external light accelerates, the duration of adjacent time windows is shortened to increase the adjustment frequency; when the rate of change in external light decreases, the length of the time window is extended to ensure a smooth change in illuminance. When there is a sudden change in external light, such as a sudden movement of clouds due to strong winds or a sudden increase in surface reflection, the rolling correction action is immediately triggered to rearrange the illuminance adjustment sequence, enabling the snow shelter lighting brightness to quickly match the new light change state. Through continuous execution of rolling corrections, the temporal correspondence between the brightness response of the snow shelter's lighting and changes in external light is updated in real time, ensuring a continuous, smooth, and uninterrupted synchronous trend in illuminance changes over time. Ultimately, this achieves temporal consistency and visual continuity between changes in the brightness of the snow shelter's internal lighting and changes in external light, providing drivers with a stable and comfortable lighting transition environment.

[0096] This invention establishes a time-correlation relationship between the external light intensity curve and the brightness response of the snow shelter's lighting, enabling the internal lighting of the snow shelter to dynamically follow and continuously match changes in external light intensity. By triggering illuminance adjustment commands in advance during periods of rapid change in external light intensity and employing a step-by-step adjustment method to smooth the illuminance transition, the lighting system can complete its brightness response before sudden changes in external light intensity, fundamentally eliminating periodic brightness fluctuations and flickering. This method effectively improves the continuity of brightness transition between the inside and outside of the shelter, allowing drivers to maintain stable visual perception during high-speed driving, reducing visual fatigue and the risk of disorientation, and enhancing the safety and comfort of the snow shelter's traffic environment.

[0097] This invention enables adaptive lighting control by continuously and dynamically correcting the timing sequence of lighting adjustments. It automatically adjusts the amplitude and rate of change in illuminance based on the rate and direction of changes in external light. This method achieves real-time dynamic coordination of lighting brightness, ensuring that the snow canopy lighting remains synchronized with external visibility conditions under varying weather conditions, snow reflection intensity, and solar altitude. Through continuous correction and smooth control, illuminance changes are more stable and natural, avoiding sudden changes in light that could stimulate the driver's visual system and effectively ensuring visual continuity and driving safety during tunnel entry and exit.

[0098] The foregoing has only described certain exemplary embodiments of the present invention by way of illustration. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the foregoing drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A method for regulating and controlling the lighting of a snow shed in an alpine tunnel based on the visual conditions of the outside world, characterized by, The method comprises the following steps: In order to realize the lighting regulation and control of the snow shed, four types of optical environment parameters including external light intensity, visibility, snow reflectivity and solar altitude are obtained, the light change information corresponding to each parameter is uniformly mapped into the same time sequence according to time sequence, and an external light change curve is generated; Based on the external light change curve, the brightness response data of the snow shed lighting system is analyzed, the external light change rate is calculated, the time interval in which the external light change rate exceeds the preset threshold is extracted, and a lighting flicker risk period is generated; In the lighting flicker risk period, the external light change curve and the snow shed lighting brightness response curve are compared in time axis, the inconsistent section of the two curves in the brightness change trend is determined, the inconsistent section is marked as a light regulation conflict point, and a light regulation conflict list is generated; According to the light regulation conflict list, the time sequence of the lighting control is adjusted, the advance triggering illumination adjustment instruction is set in the time interval corresponding to each light regulation conflict point, and the illumination adjustment process is divided into multiple time interval continuous step adjustment stages; Based on the time sequence adjusted lighting output result, the gradient amplitude and the lifting rate of the illumination change are set, the time corresponding relationship between the external light change curve and the snow shed lighting brightness response curve is continuously updated, and the lighting control time sequence is rolling corrected.

2. The high-altitude tunnel snowshed lighting regulation method based on visual conditions of the outside world according to claim 1, characterized in that, The generation steps of the external light change curve are as follows: For the external optical environment of the snow shed, the real-time change information of four types of optical environment parameters including external light intensity, visibility, snow reflectivity and solar altitude is obtained, which is used to reflect the whole day light change characteristics and the air transparency, snow surface reflection characteristics and solar irradiation angle; After obtaining the four types of optical environment parameters, the external light intensity, visibility, snow reflectivity and solar altitude are uniformly aligned in time dimension, a unified time reference is established, the change information of each parameter is rearranged according to the same time interval, and a continuous time sequence is formed; After completing the time reference alignment, the change value range of the four types of optical environment parameters is uniformly processed, and the comparability of each parameter in time dimension is realized through proportional adjustment and physical quantity conversion; The change sequence of the uniformized external light intensity, visibility, snow reflectivity and solar altitude is continuously connected according to time sequence, and the external light change curve is generated.

3. The high-altitude tunnel snowshed lighting regulation method based on visual conditions of the outside world according to claim 2, characterized in that, In the process of generating the external light change curve, the time change record of the external light intensity is taken as the time main line, the visibility change, the snow reflectivity change and the solar altitude change are adjusted in time, and each time point corresponds to the observation results of the four types of optical environment parameters.

4. The high-altitude tunnel snowshed lighting regulation method based on visual conditions of the outside world according to claim 2, characterized in that, The generation steps of the lighting flicker risk period are as follows: After the generation of the external light change curve for the lighting regulation and control of the snow shed, the change trend of the external light change curve in the continuous time range is analyzed, the light intensity change amplitude and change direction of each time period are extracted; After completing the external light change trend segmentation analysis, the brightness response data of the snow shed internal lighting is obtained, and the time corresponding relationship is established in the same time range, so that each time point contains the synchronous record of the external light intensity and the snow shed lighting brightness; After obtaining the external light change curve and the snow shed lighting brightness response data, the external light change rate is calculated, and the time period of sudden increase and sudden decrease of the external light change rate is identified through time scaling processing; After completing the analysis of the external light change rate, a preset threshold is set to divide the stable state and the severe change state of the light change, and the time intervals of the external light change rate exceeding the preset threshold are arranged continuously to generate the lighting flicker risk period.

5. The high-altitude tunnel snowshed lighting regulation method based on visual conditions of the outside world according to claim 4, characterized in that, The steps of generating the light adjustment conflict list are as follows: After identifying the lighting flicker risk period, the external light change curve and the snow shed lighting brightness response curve are divided into time intervals and synchronized in time, and the starting time of the lighting flicker risk period is taken as the reference point to divide the lighting flicker risk period into continuous sampling segments and establish the brightness change sequence under the unified time axis; After completing the time axis alignment, the brightness change trend of the external light change curve and the snow shed lighting brightness response curve is analyzed in direction and compared in amplitude, the light change direction, the snow shed brightness change direction and the change amplitude difference of each sampling point are recorded, and the brightness trend comparison sequence is formed; After obtaining the brightness trend comparison sequence, the time segments where the two curves are inconsistent in brightness change trend are identified, the start and end times, the duration and the brightness difference of each inconsistent segment are recorded, and the brightness difference time distribution map is established; The starting time point of each inconsistent segment of the brightness change trend is marked as a light adjustment conflict point, and a light adjustment conflict list is generated according to the time sequence.

6. The high-altitude tunnel snowshed lighting regulation method based on visual conditions of the outside world according to claim 5, characterized in that, When generating the light adjustment conflict list, the occurrence time, the duration of the corresponding inconsistent segment, the brightness difference peak, the external light change rate and the snow shed lighting brightness change direction of each light adjustment conflict point are recorded, and the complete conflict distribution is formed by arranging in time sequence.

7. The high-altitude tunnel snowshed lighting regulation method based on visual conditions of the outside world according to claim 5, characterized in that, According to the light adjustment conflict list, the lighting control time sequence is adjusted, the advance triggering illumination adjustment instruction is set before the time interval corresponding to each light adjustment conflict point, and the illumination adjustment process is divided into time interval continuous step adjustment stages as follows: After obtaining the light adjustment conflict list, each light adjustment conflict point in the list is analyzed to determine the time position and influence range of the light adjustment conflict point, and the conflict influence interval is determined according to the external light change characteristics to form a continuous conflict interval sequence on the time axis; After determining the light adjustment conflict point and its influence interval, an advance triggering illumination adjustment instruction is set before the time interval corresponding to each light adjustment conflict point, and the increase or decrease of the snow shed lighting brightness is controlled according to the direction of the external light change based on the starting time of the light adjustment conflict point; After completing the setting of the advance triggering illumination adjustment instruction, the illumination adjustment process is divided into multiple time interval continuous step adjustment stages, and each step adjustment stage performs an illumination fine adjustment operation to make the illumination change smooth and progressive in time; After the step adjustment stage is executed, the time sequence of the lighting control is continuously updated by adjusting the step adjustment time interval and direction.

8. The high-altitude tunnel snowshed lighting regulation method based on visual conditions of the outside world according to claim 1, characterized in that, Based on the time sequence adjusted lighting output result, the gradual change amplitude and the lifting rate of the illumination change are set, the time corresponding relationship between the external light change curve and the snow shed lighting brightness response curve is continuously updated, and the lighting control time sequence is adjusted through the rolling correction method as follows: After completing the lighting time sequence adjustment and obtaining the new lighting output result, the time series analysis is performed on the lighting output data, the illumination change curve is divided into continuous sampling intervals, and the snow shed lighting brightness value, the change rate and the duration are extracted; After the snow shed lighting output change characteristics are determined, the gradual change amplitude and the lifting rate of the illumination change are set according to the external light change trend, the external light change direction and the rate are determined through the time axis comparison, so that the lighting brightness response and the external light maintain continuous correspondence; After setting the illumination change parameters, the time corresponding relationship between the external light change curve and the snow shed lighting brightness response curve is continuously updated, the time deviation is corrected according to the real-time light data, and the illumination change rhythm is kept consistent; On the basis of continuously updating the time corresponding relationship, the lighting control time sequence is dynamically optimized in the rolling correction mode, the snow shed lighting brightness change and the external light change are kept in real-time synchronization and smooth transition through continuous time window monitoring and adjustment.

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