Method for constructing a tunnel sunshade based on a tunnel entrance dimming model

Abstract

The present application relates to the field of tunnel light adjustment, and particularly relates to a method for constructing a tunnel sunshade based on a tunnel entrance light adjustment model, comprising: collecting illumination test data of a plurality of target tunnels; performing human eye recognition reaction time tests on a plurality of target testers based on the illumination test data and a SCANeR driving system; obtaining a correlation relationship between the reaction time and the maximum environmental illumination corresponding to a test vehicle speed; obtaining a relationship between an initial illumination value and an illumination difference; constructing a light adjustment model; and sequentially completing the calculation of a safety illumination difference under the initial illumination, the calculation of the light transmittance of each section of the sunshade, and the calculation of the design length of each section of the sunshade based on the light adjustment model. The present application is based on five types of regions in China classified according to solar radiation, and systematically collects typical illumination characteristic data, is suitable for the design of a tunnel entrance light adjustment model in a nationwide range, and can provide key safety threshold and range references for the engineering design of a tunnel entrance sunshade and other active light adjustment facilities.

Description

Technical Field

[0001] This invention relates to the field of tunnel lighting, and more particularly to a method for constructing a tunnel sunshade based on a tunnel entrance lighting model. Background Technology

[0002] With the development of my country's economy, the demand for transportation is gradually increasing, and the volume of tunnel operation is also increasing. With the variability of traffic volume and environmental factors such as severe weather, especially the impact of severe environments such as ice, snow, rain, fog, and abnormal light on the increasingly large domestic road network, the black hole effect generated when entering the tunnel has a great impact on driving safety.

[0003] When transitioning from the normal driving environment to the unique environment of a tunnel, the abrupt change in visual environment can significantly impact a driver's vision. Especially on a clear day, the transition from natural highway lighting to the artificial lighting at the tunnel entrance creates a stark contrast in light conditions. This difference can lead to visual lag, causing temporary visual impairment and seriously jeopardizing driver safety. The dangers and severity of the "black hole" phenomenon at tunnel entrances to driving safety were recognized as early as the 1960s, making the improvement of the lighting environment at tunnel entrances an important research direction. Furthermore, through numerous dynamic viewpoint driving experiments, and by proposing the "maximum transient pupil area per unit area" (MTPA) as a visual load evaluation index, the improvement range of the illuminance transition zone under different speed limits and visual environments was determined. A series of measures to mitigate the "black hole" or "white hole" effect at tunnel entrances and exits were also proposed. The excessive illuminance difference between the inside and outside of the tunnel entrance is the main cause of the "black hole effect," thus affecting driver safety at the tunnel entrance. Existing research lacks in-depth and practical consideration of factors such as the direction, distance, light-reducing structures, and different locations of the tunnel entrance. Summary of the Invention

[0004] Therefore, this invention provides a method for constructing a tunnel sunshade based on a tunnel entrance dimming model, in order to improve the accuracy of the dimming model and broaden its application scope.

[0005] To achieve the above objectives, the present invention provides a method for constructing a tunnel sunshade based on a tunnel entrance dimming model, comprising:

[0006] Step S1: In response to the preset illuminance conditions, collect illuminance test data for several target tunnels. For a single target tunnel, the measurement points include at least the normal ambient illuminance, the illuminance outside the entrance, the average illuminance at the entrance, the illuminance while driving inside the tunnel, the average illuminance at the exit, and the illuminance outside the exit.

[0007] Step S2: Based on the illuminance test data and the SCANeR driving system, conduct human eye recognition reaction time tests on several target test subjects to obtain black hole effect test data and white hole effect test data under maximum illuminance-reaction time at several test vehicle speeds; the test vehicle speeds include 60km / h, 80km / h and 100km / h;

[0008] Step S3: After performing nonlinear curve fitting analysis on the black hole effect test data and white hole effect test data respectively, obtain the correlation formula between the reaction time of the corresponding test vehicle speed and the maximum ambient illuminance:

[0009] ,

[0010] In the formula: T is the driver's reaction time; x0 is the maximum illuminance; y0, a1, a2, t1, and t2 are different constants under different conditions;

[0011] Step S4: Perform a test on the safe illuminance gradient within the preset illuminance range to obtain an illuminance gradient fitting curve that satisfies the safe reaction time, and obtain the relationship between the initial illuminance value and the illuminance difference:

[0012] ,

[0013] In the formula: y is the illuminance difference, x is the initial illuminance value, and y3, a3 and t3 are different constants;

[0014] Step S5, construct the dimming model according to the following formula:

[0015] ,

[0016] In the formula: y is the illuminance difference; x is the initial illuminance value;

[0017] Step S6: Based on the dimming model, calculate the safe illuminance difference under the initial illuminance, calculate the light transmittance of each section of the sunshade, and calculate the design length of each section of the sunshade.

[0018] Further, in step S2, the human eye recognition reaction time test includes:

[0019] Step S201: Set the target contrast to 0.15;

[0020] Step S202: Install an LED light above the front side of the driver's position in the SCANeR system driving simulation device. The maximum illuminance of the LED light is 120,000 lx.

[0021] Step S203: Set the external illuminance of the LED lights in the tunnel to 120,000 lx, set the internal illuminance in the tunnel to 2,000 lx to 600 lx, and set the safe reaction time for the driver to 1.2s to 1.5s;

[0022] Step S204: Select test subjects to conduct driving simulation tests to complete the human eye recognition reaction time test. Among them, the test with human eye recognition reaction time less than 100ms is retested, and the test data with human eye recognition reaction time greater than 4000ms is discarded.

[0023] Further, in step S6,

[0024] In response to the safe illuminance difference being greater than 2500 lx, the illuminance difference is recorded and substituted into the dimming model to obtain the safe illuminance difference again;

[0025] In response to a safe illuminance difference of less than or equal to 2500 lx, the illuminance difference is recorded and the light transmittance of the corresponding section of the shade is calculated.

[0026] Further, in step S6, the light transmittance of each section of the sunshade is calculated according to the following formula:

[0027] τ1=R / K, where τ1 is the light transmittance of the first section of the sunshade, R is the target reduction rate, and K is the geometric effective light transmittance coefficient of the first section of the sunshade;

[0028] τ2=I2 / (I 2,in ×K2), where τ2 is the light transmittance of the second section of the shade canopy, and I2 is the illuminance of the second section of the shade canopy after reduction; I 2,in K1 represents the incident light intensity of the second section of the sunshade; K2 represents the geometric effective light transmittance coefficient of the second section of the sunshade.

[0029] τn= I n / (I n,in ×K n ), where τn is the light transmittance of the nth segment of the shade, I n I represents the reduced illuminance of the nth segment of the sunshade; n,in K represents the incident light intensity of the nth segment of the sunshade. n Let be the geometric effective light transmittance coefficient of the nth segment of the sunshade;

[0030] For a single sunshade, K=K2=K n .

[0031] Furthermore, the design length of each section of the sunshade is calculated according to the following formula:

[0032] L n ={ }×V,

[0033] Among them, L n Let n be the design length of the nth segment of the sunshade. R n is the target reduction rate of the nth segment of the sunshade. R 1 represents the target reduction rate of the first section of the sunshade, and V represents the most unfavorable speed limit in the highway tunnel, V=100km / h.

[0034] Furthermore, it also includes:

[0035] Step S7: Obtain the illumination parameters of the preset area across the country, and divide the preset area into Class I to Class V areas according to the total annual solar radiation and the noon illumination on a sunny summer day.

[0036] Step S8: Based on the dimming model, design reference data for regions from Class I to Class V are completed sequentially; the design reference data includes the light transmittance of each section of the sunshade and the design length of each section of the sunshade.

[0037] Compared with existing technologies, the advantages of this invention are as follows: Based on five categories of regions across the country classified by solar radiation, this invention systematically collects typical illuminance characteristic data and proposes a set of reference design schemes for tunnel entrance dimming models applicable nationwide. Building upon existing research, it expands the scope of indoor dimming models and incorporates high-precision SCANeR vehicle control driving simulation equipment to determine the differences in reaction time for drivers encountering the "black hole effect" and "white hole effect" at different external environmental illuminance levels at vehicle speeds of 60km / h, 80km / h, and 100km / h.

[0038] Furthermore, this invention explores and determines the critical illuminance range for drivers to safely enter tunnels under the most unfavorable operating conditions, dominated by the "black hole effect," providing more detailed theoretical support for the subsequent establishment of a dimming model for tunnel entrances and exits.

[0039] Furthermore, the model and formulas of this invention can provide key safety thresholds and range references for the engineering design of tunnel entrance sunshades and other active dimming facilities nationwide. Its core value lies in effectively mitigating the adverse effects of drastic changes in light environment at tunnel entrances and exits on the driver's visual adaptation process, thereby significantly weakening or even eliminating the negative impacts of the "black hole effect" and "white hole effect." This provides quantitative support for the structural design of tunnel entrance sunshades, effectively controlling the light adaptation time within safe thresholds and ensuring driver safety when entering and exiting tunnels. Attached Figure Description

[0040] Figure 1 This is a flowchart illustrating the method for constructing a tunnel sunshade based on a tunnel entrance dimming model, as described in an embodiment of the present invention.

[0041] Figure 2This is a schematic diagram illustrating the construction of a driving simulation scenario for testing human eye recognition reaction time according to an embodiment of the present invention;

[0042] Figure 3 This is a fitted curve of the "black hole effect" at a vehicle speed of 100km / h according to an embodiment of the present invention;

[0043] Figure 4 This is a fitted curve of the "white hole effect" at a vehicle speed of 100km / h according to an embodiment of the present invention;

[0044] Figure 5 This is a graph showing the safe illuminance gradient fitting curve according to an embodiment of the present invention;

[0045] Figure 6 This is a flowchart for calculating the safe illuminance difference under the initial illuminance in an embodiment of the present invention. Detailed Implementation

[0046] To make the objectives and advantages of the present invention clearer, the present invention will be further described below with reference to embodiments; it should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention.

[0047] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0048] Please see Figure 1 An embodiment of the present invention provides a method for constructing a tunnel sunshade based on a tunnel entrance dimming model, comprising:

[0049] Step S1: In response to the preset illuminance conditions, collect illuminance test data for several target tunnels. For a single target tunnel, the measurement points include at least the normal ambient illuminance, the illuminance outside the entrance, the average illuminance at the entrance, the illuminance while driving inside the tunnel, the average illuminance at the exit, and the illuminance outside the exit.

[0050] Step S2: Based on the illuminance test data and the SCANeR driving system, conduct human eye recognition reaction time tests on several target test subjects to obtain black hole effect test data and white hole effect test data under maximum illuminance-reaction time at several test vehicle speeds; the test vehicle speeds include 60km / h, 80km / h and 100km / h;

[0051] Step S3: After performing nonlinear curve fitting analysis on the black hole effect test data and white hole effect test data respectively, obtain the correlation formula between the reaction time of the corresponding test vehicle speed and the maximum ambient illuminance:

[0052] ,

[0053] In the formula: T is the driver's reaction time; x0 is the maximum illuminance; y0, a1, a2, t1, and t2 are different constants under different conditions;

[0054] When the vehicle speed is 60km / h under the black hole effect, y0=557904.51064, a1=-0.56323±0.21886, t1=-0.56323±0.21886, a2=-557903.38406, t2=1.89853E10;

[0055] When the vehicle speed was 80 km / h under the black hole effect, y0 = -0.26844 ± 3.052, a1 = -0.68921 ± 0.21345, t1 = 6014.23619 ± 3537.88947, a2 = 1.66115 ± 2.78681, t2 = -77639.19364 ± 85869.25058;

[0056] When the vehicle speed was 100km / h under the black hole effect, y0=-0.26844±3.052, a1=-10.60038, t1=519440.81943±1.50192E9, a2=-13.48273, t2=493200.63321±5.23166E8;

[0057] When the vehicle speed was 60 km / h under the white hole effect, y0 = 1.27278 ± 0.23123, a1 = -0.76333 ± 0.13485, t1 = 9971.58197 ± 3906.44417, a2 = 0.01495 ± 0.06343, t2 = -19275.63839 ± 23049.04984;

[0058] When the vehicle speed was 80 km / h under the white hole effect, y0=59894.73047, a1=-0.56333 ± 0.1005, t1=5505.82189 ± 2299.32933, a2=-59893.71505, t2=-6.48781E9;

[0059] When the vehicle speed was 100km / h under the white hole effect, y0=1.20591 ± 0.08272, a1=-0.78957 ±0.06434, t1=10051.42936 ± 2625.40806, a2=0.001 ± 0.00277, t2=-9689.37394 ±4291.78322;

[0060] Step S4: Perform a test on the safe illuminance gradient within the preset illuminance range to obtain an illuminance gradient fitting curve that satisfies the safe reaction time, and obtain the relationship between the initial illuminance value and the illuminance difference:

[0061] ,

[0062] In the formula: y is the illuminance difference, x is the initial illuminance value, and y3, a3, and t3 are different constants; a3 = -114651.93116 ± 914.60018; t3 = 110199.86696 ± 1410.20437; y3 = 114395.41022 ± 968.49966;

[0063] Step S5, construct the dimming model according to the following formula:

[0064] ,

[0065] In the formula: y is the illuminance difference; x is the initial illuminance value;

[0066] Step S6: Based on the dimming model, calculate the safe illuminance difference under the initial illuminance, calculate the light transmittance of each section of the sunshade, and calculate the design length of each section of the sunshade.

[0067] Specifically, in step S1, the following tunnels in Jinan City are selected: Shifangyushan Tunnel (west to east, with a shaded entrance and a light-transmitting sunshade at the exit); Shifangyushan Tunnel (east to west, with a sunshade at the entrance); Laohudongshan Tunnel (west to east, with a shaded entrance); Laohudongshan Tunnel (east to west, with a sunshade at the entrance); Wangyue Road Tunnel (north to south, with sunshades at both entrances and exits, but no shade); Wangyue Road Tunnel (south to north, with sunshades at both entrances and exits, but a shaded entrance). The preset illuminance condition is to measure the illuminance at noon on a clear day. All tunnel entrances are included in the above categories. By measuring the illuminance values ​​at different distances inside and outside the tunnel entrances at noon, the influence of direction on the difference in illuminance inside and outside the tunnel entrance is refined, and an illuminance test data table is obtained.

[0068] Table 1 Illuminance Test Data

[0069]

[0070] Table 1, based on the illuminance test data, shows that the orientation of the sunshade has little impact on the illuminance value inside the tunnel. Therefore, it can be determined that the greater the illuminance difference, the more pronounced the "black hole effect" becomes to the human eye. Through actual data measurement, it can be concluded that the design illuminance value for the middle section of tunnels in my country is between 20-200 lx, while the illuminance value near the tunnel entrance where the black hole effect occurs can be designed between 200-600 lx.

[0071] Specifically, in step S2, the human eye recognition reaction time test includes:

[0072] Step S201: Set the target contrast to 0.15;

[0073] Step S202: Install an LED light above the front side of the driver's position in the SCANeR system driving simulation device. The maximum illuminance of the LED light is 120,000 lx.

[0074] Step S203: Set the external illuminance of the LED lights in the tunnel to 120,000 lx, set the internal illuminance in the tunnel to 2,000 lx to 600 lx, and set the safe reaction time for the driver to 1.2s to 1.5s;

[0075] Step S204: Select test subjects to conduct driving simulation tests to complete the human eye recognition reaction time test. Among them, the test with human eye recognition reaction time less than 100ms is retested, and the test data with human eye recognition reaction time greater than 4000ms is discarded.

[0076] Specifically, visual acuity usually refers to visual acuity, that is, the human eye's ability to distinguish the clarity of a target, typically measured by visual angle. Sheellen proposed a scale for testing human visual acuity based on a 1-minute visual angle standard, using the standard position of the 1-minute visual angle as the basic visual target. Building on Sheellen's theory, Landolt further researched and combined Sheellen's theory with practice, creating the Landolt ring. He determined that the test subject could clearly identify the corresponding details by judging the direction of the opening, using this as the visual target for testing human visual acuity. This test uses the Landolt ring as the visual target to simulate obstacles, testing the driver's perception and recognition of obstacles under different conditions. Besides the size of the visual target, contrast also has a significant impact on the human eye's visual response. Generally, the higher the contrast, the clearer and more prominent the target, making it easier to identify. Conversely, a low contrast makes the target appear close to the background brightness, appearing dim and difficult to identify. The contrast threshold is usually defined as the contrast at which the test subject just barely spots the target. In summary, the visual target contrast was set to 0.15 in this experiment, which meets the requirements for most visual observation situations.

[0077] Please see Figure 2 The invention embodiment shows a schematic diagram of the driving simulation scenario setup for human eye recognition reaction time testing. This test uses the SCANeR driving simulation device to drive at different speeds, and uses two external LED lights to simulate the maximum actual illuminance. According to the illuminance instrument test, the illuminance value of the two LED lights is about 120,000 lx when the controller is set to 100%, which can simulate the illuminance of sunlight at noon in summer mentioned above. It has been verified that the purpose of simulating the black hole effect can be achieved by using a dimming controller to make sudden changes in light.

[0078] In step S203, the highest illuminance value for this test is set at approximately 120,000 lx, and the illuminance inside the tunnel is set between 200 and 600 lx. According to the *Traffic Engineering Handbook*, the safe reaction time for drivers is determined to be 1.2 to 1.5 seconds. Based on this safe reaction time, the minimum illuminance value required to reduce from 120,000 lx to meet the safe reaction time requirement can be determined. Similarly, other illuminance gradients that meet the safe reaction time requirement can be derived. As analyzed above, the black hole effect and white hole effect mainly occur at the tunnel entrance. Combining the measured illuminance at the entrances and exits of several tunnels in the Jinan area mentioned earlier, a main illuminance range of 2000–60000 lx can be set to simulate the illuminance at the tunnel entrance, and a main illuminance range of 200–600 lx can be set to simulate the illuminance at the tunnel entrance.

[0079] In step S204, based on the physiological structure of the human eye, externally emitted light can form an image on the retina and finally reach the cerebral cortex to form vision. Studies on the stability of human visual perception show that the eyeball gradually becomes spherical after birth, and this change is possible until the age of 20. However, by age 20, the change generally stops, and the lens in the eyeball is extremely thin before age 20, making changes more likely. After age 20, the lens gradually stabilizes. Furthermore, experienced drivers are more adaptable to complex road conditions, while drivers aged 20-30 generally have less driving experience and weaker reaction time to sudden road situations. Considering the worst-case scenario, 10 participants aged 20-30 with no eye diseases and corrected visual acuity of 0.8 or higher, and 5 participants aged 30-50 were selected for driving simulation testing.

[0080] Specifically, in step S2, test data on the black hole effect and white hole effect under maximum illuminance-reaction time at several test vehicle speeds are acquired. The test vehicle speeds include 60 km / h, 80 km / h, and 100 km / h. Specifically, the reaction time of the "black hole effect" is measured when the illuminance decreases from 60,000 lx to 2,000 lx at test speeds of 60 km / h, 80 km / h, and 100 km / h, while the reaction time of the "white hole effect" is measured when the illuminance increases from 250 lx to 60,000 lx-2,000 lx. After removing values ​​with large errors, 10 sets of experiments are conducted for each test subject to simulate 18 illuminance change ranges and the corresponding "black hole effect" (from dark to bright) and "white hole effect" (from bright to dark) for each illuminance change range. Under simulated conditions of varying vehicle speeds, the human eye's reaction time to changes in ambient light intensity shows a positive correlation with these changes. Specifically, as maximum illuminance increases, the adaptation time of the human eye lengthens. Experimental results indicate that within the same illuminance variation range, the "black hole effect" significantly impacts human eye reaction time more than the "white hole effect." Further analysis shows that under the "white hole effect" conditions, vehicle speed has a relatively limited impact on human eye reaction time, and changes in ambient illuminance have a relatively small impact on human eye reaction time. Referring to relevant research on tunnel safety thresholds in the *Traffic Engineering Handbook*, the driver's safe reaction time should be controlled within the range of 1.2–1.5 seconds. Test data shows that under the "white hole effect" conditions, the driver's reaction time basically meets this safety threshold requirement, indicating that its impact on driving safety is relatively small. Under the "black hole effect" conditions, as maximum illuminance increases, the human eye's adaptation time to the ambient light intensity shows a significant increasing trend, with an impact far greater than that of the "white hole effect," increasing reaction time by 35%–48% under the same illuminance change.

[0081] Understandably, the human eye recognition reaction time test was conducted in ScaneR's dedicated laboratory. Based on the ScaneR driving system, two 400W LEDs were placed next to the driving simulation equipment. After testing with an illuminance meter, when the controller was set to 100%, the brightness of the two lights approached 130,000 lx, essentially simulating the most unfavorable external lighting conditions. Therefore, two external LEDs were used to simulate the external light environment, and software synchronization was achieved through two dimming controllers under 400W to adjust the external light environment for driving the vehicle. First, the ScaneR vehicle control driving simulation equipment was run to set up a straight road, with various surrounding scenery added. Driving simulations were then conducted based on this constructed road. First, simulate driving on a straight road. A Randall beacon is projected onto the screen of the ScaneR system. At the same time, two external 300W LED lights are used to simulate the external light environment. After the driver adapts, the sky is set to suddenly darken on ScaneR, and the light brightness is reduced to make the ambient light close to that of a tunnel. This continues until the driver readjusts and recognizes the direction of the beacon and steps on the brake. ScaneR then tests the driver's reaction time.

[0082] Specifically, in step S3, nonlinear curve fitting analysis is performed on the black hole effect test data and the white hole effect test data, respectively. The nonlinear curve fitting analysis is performed using Origin software. The fitting process aims to accurately characterize the function model of the driver's reaction time as a function of key indicators of the light environment, such as maximum illuminance.

[0083] When driving at 60 km / h under the black hole effect, the above model was fitted and its significance was tested using Origin software. The results showed that the model's coefficient of determination (R²) was as high as 0.98077. This result indicates that the model has a high goodness of fit, strong explanatory power for the data, and a high degree of agreement with the experimental data, fully demonstrating a significant statistical positive correlation between driver reaction time and maximum illuminance, showing a strong positive association between the two. Further analysis shows that the model has good applicability and reliability in the range of maximum illuminance from 2000 lx to 60000 lx.

[0084] When the driving speed is 80 km / h under the black hole effect, the coefficient of determination R² is 0.99087, indicating that the model has a very strong explanatory power for the data and an excellent fit. This result clearly reveals a strong positive correlation between maximum illuminance and driver reaction time.

[0085] Please see Figure 3The "black hole effect" fitting curve of this embodiment of the invention at a vehicle speed of 100 km / h shows that when the vehicle speed is 100 km / h under the black hole effect, the model's coefficient of determination R² is 0.9771, demonstrating excellent fitting effect and strong explanatory power, accurately reflecting the driver's reaction time with maximum illuminance at this specific vehicle speed. Data analysis further confirms that within the maximum illuminance range of 2000 lux to 60000 lux, there is a significant positive statistical correlation between the driver's reaction time and the maximum illuminance. The model exhibits good applicability and reliability within this illuminance range.

[0086] A comprehensive analysis of the fitting results of the driver's reaction time versus maximum illuminance curves under the "black hole effect" conditions at simulated vehicle speeds of 60 km / h, 80 km / h, and 100 km / h using Origin software shows that the correlation formula between reaction time and maximum ambient illuminance at the corresponding test vehicle speeds effectively characterizes the positive correlation between the two. The goodness of fit at different vehicle speeds confirms that this formula has good consistency with the positive correlation law that driver reaction time increases with increasing maximum illuminance. Further evaluation shows that it exhibits good applicability and robust predictive ability within an illuminance range of 2000 lx to 60000 lx. Analysis of the fitting results of the correlation formula between reaction time and maximum ambient illuminance at the corresponding test vehicle speeds indicates that the reaction time of the "black hole effect" shows a trend of increasing with increasing initial illuminance. Furthermore, experimental data reveals that the reaction time of this effect also shows a corresponding increase with increasing speed.

[0087] When the driving speed is 60 km / h under the white hole effect, the model's determination coefficient R² is 0.98045;

[0088] When the driving speed is 80 km / h under the white hole effect, the model's determination coefficient R² is 0.97063;

[0089] Please see Figure 4 The figure shows the fitting curve of the "white hole effect" when the vehicle speed is 100km / h in an embodiment of the present invention. When the vehicle speed is 100km / h under the white hole effect, the coefficient of determination R² of the model is 0.98295, showing excellent fitting effect and strong explanatory power. It can accurately reflect the law of driver reaction time changing with maximum illuminance at this specific vehicle speed.

[0090] Under simulated vehicle speeds of 60 km / h, 80 km / h, and 100 km / h, a fitting analysis was conducted on the relationship between driver reaction time and maximum illuminance at the tunnel entrance, targeting "black hole effect" and "white hole effect" scenarios. The results show that within the illuminance range of 2000 lx to 60000 lx, the driver reaction time and maximum illuminance follow a descriptive relationship. The coefficients of determination (R²) obtained from the Origin software fitting are all greater than 0.95, indicating a significant positive correlation between the two. The fitting results at different vehicle speeds consistently confirm that the correlation formula between reaction time and maximum ambient illuminance at the corresponding test vehicle speeds can effectively characterize the positive correlation characteristic of driver reaction time increasing with increasing maximum illuminance. After parameter optimization, the goodness of fit under each vehicle speed condition shows that the formula has good consistency with this positive correlation law.

[0091] Please see Figure 5 Specifically, it refers to the safety illuminance gradient fitting curve of the embodiment of the present invention. In step S4, the driver's safe reaction time should be at least within the range of 1.2 to 1.5 seconds. The actual driving safety recognition time of the driver is about 1.2 seconds. However, in the indoor test, due to the early knowledge of the appearance of obstacles, the search time is reduced, and there is no interference from the external environment, the reaction time is shorter. According to the regulations of traffic engineering, this time should be within 0.7 seconds, including 0.4 seconds of perception reaction time and 0.3 seconds of braking effect time. That is, if the direction of the target is identified within 0.7 seconds, it is considered that the change in the light environment will not affect the driver's visual reaction. The analysis of the process of establishing the driver's reaction time and the maximum illuminance function model shows that the "black hole effect" has a much greater impact on the human eye than the "white hole effect," and the simulated speed of 100 km / h has a greater impact on the human eye than the simulated vehicle speeds of 80 km / h and 60 km / h. Based on the above, a driver reaction time test was conducted at a speed of 100 km / h under the "black hole effect" to obtain an illuminance gradient fitting curve that satisfies the safe reaction time. Curve fitting results using Origin software show that the initial illuminance value L... b With illuminance difference L c The coefficient of determination (R²) of the relationship between the initial illuminance value and the illuminance difference is as high as 0.99994, indicating a very strong positive correlation between illuminance and the target parameter. Given its excellent goodness of fit, the relationship between the initial illuminance value and the illuminance difference can be used as the core dimming model relationship for the illuminance gradient design of the shade canopy, and illuminance can be verified.

[0092] Please see Figure 6 This is a flowchart illustrating the calculation of the safe illuminance difference under the initial illuminance according to an embodiment of the present invention. Specifically, in step S6,

[0093] In response to the safe illuminance difference being greater than 2500 lx, the illuminance difference is recorded and substituted into the dimming model to obtain the safe illuminance difference again;

[0094] In response to the safe illuminance difference being less than or equal to 2500 lx, the illuminance difference is recorded and the light transmittance of the corresponding section of the shade is calculated;

[0095] When the sunshade is eventually reduced to 2500 lx or below, the changes in the ambient temperature when entering the tunnel will not affect the driver's driving safety.

[0096] Specifically, in step S6, regarding the light transmittance of each section of the sunshade, where,

[0097] The light transmittance of the first and subsequent sections of the shade canopy is calculated using the following formula:

[0098] τ1=R / K, where τ1 is the light transmittance of the first section of the sunshade, R is the target reduction rate, R=I1 / I0, and K is the geometric effective light transmittance coefficient of the first section of the sunshade;

[0099] τ2=I2 / (I 2,in ×K2), where τ2 is the light transmittance of the second section of the shade canopy, and I2 is the illuminance of the second section of the shade canopy after reduction; I 2,in K2 represents the incident light intensity of the second section of the sunshade; K2 is the geometric effective light transmittance coefficient of the second section of the sunshade.

[0100] τn= I n / (I n,in ×K n ), where τn is the light transmittance of the nth segment of the shade, I n I represents the reduced illuminance of the nth segment of the sunshade; n,in K represents the incident light intensity of the nth segment of the sunshade. n The geometric effective light transmittance coefficient of the nth segment of the sunshade;

[0101] Among them, I n,in =I n-1 ×F (n-1),n +I0×(1-F (n-1),n )×R env +I0×D sky ;

[0102] Where F is the forward viewing angle coefficient, and its value ranges from 0.7 to 0.9; R env For environmental reflectance, light-colored paving: 0.3-0.5, concrete / asphalt: 0.1-0.2, lawn: 0.1-0.15, recommended design value: 0.2; D sky The ratio of diffused light from the sky is 0.1-0.15 for clear skies at midday in summer, with a recommended design value of 0.12.

[0103] For a single sunshade, K=K2=K n ;

[0104] Among them, if the sunshade is a plane awning with the best tilt angle, i.e. the benchmark model, K≈0.95~0.99, and the middle value is taken as 0.97;

[0105] If the awning is a zigzag awning, the included angle is 180°: K ≈ 1.0; the included angle is 170°: K ≈ 0.85~0.95; and the included angle is 160°: K ≈ 0.75~0.85.

[0106] If the sunshade is a gently sloping, wave-shaped sunshade, K≈0.90~0.98, take the average value of 0.94.

[0107] Specifically, the design length of each section of the sunshade is calculated according to the following formula:

[0108] L n ={ }×V

[0109] Among them, L n Let n be the design length of the nth segment of the sunshade. R n is the target reduction rate of the nth segment of the sunshade. R 1 represents the target reduction rate of the first section of the sunshade, and V represents the most unfavorable speed limit in the highway tunnel, V=100km / h.

[0110] Specifically, it also includes:

[0111] Step S7: Obtain the illumination parameters of the preset area across the country, and divide the preset area into Class I to Class V areas according to the total annual solar radiation and the noon illumination on a sunny summer day.

[0112] Step S8: Based on the dimming model, design reference data for regions from Class I to Class V are completed sequentially; the design reference data includes the light transmittance of each section of the sunshade and the design length of each section of the sunshade.

[0113] In step S7, the solar radiation, light intensity, and illuminance in different regions of China are affected by multiple factors, such as altitude, climate conditions, and latitude and longitude. Illuminance varies considerably, making it difficult to directly derive the distribution pattern. However, by combining the solar radiation distribution across China with measurements of illuminance in some typical cities, the maximum illuminance at noon in each region can be calculated using relevant data from the "Detailed Rules for Lighting Design of Highway Tunnels." my country can be divided into five categories based on solar radiation. Category I regions are those with the richest solar energy resources, with an annual total solar radiation of 6680-8400 MJ / m², equivalent to a daily radiation of 5.1-6.4 kWh / m². These regions include northern Ningxia, northern Gansu, eastern Xinjiang, western Qinghai, and western Tibet. The western part of Tibet has the richest solar energy resources, reaching a maximum of 2333 kWh / m² (daily radiation of 6.4 kWh / m²). Category II regions are those with relatively abundant solar energy resources, with an annual total solar radiation of 5850-6680 MJ / m², equivalent to 4.5-5.1 kWh / m² of daily radiation. These regions include northwestern Hebei, northern Shanxi, southern Inner Mongolia, southern Ningxia, central Gansu, eastern Qinghai, southeastern Tibet, and southern Xinjiang. Category III regions are those with moderate solar energy resources, with an annual total solar radiation of 5000-5850 MJ / m², equivalent to 3.8-4.5 kWh / m² of daily radiation. The four categories of regions with poor solar energy resources mainly include Shandong, Henan, southeastern Hebei, southern Shanxi, northern Xinjiang, Jilin, Liaoning, Yunnan, northern Shaanxi, southeastern Gansu, southern Guangdong, southern Fujian, northern Jiangsu, northern Anhui, and southwestern Taiwan. These include Hunan, Hubei, Guangxi, Jiangxi, Zhejiang, northern Fujian, northern Guangdong, southern Shaanxi, northern Jiangsu, southern Anhui, Heilongjiang, and northeastern Taiwan. The five categories of regions, mainly including Sichuan and Guizhou provinces, have the least solar energy resources in my country, with an annual total solar radiation of 3350-4200 MJ / m², equivalent to only 2.5-3.2 kWh / m² of daily radiation. Since the "black hole effect" and "white hole effect" are mainly related to the large difference in illuminance caused by excessive changes in light, we can mainly consider the impact of summer noon illuminance and tunnel illuminance in representative cities in these five types of regions on driving safety. Table 2 shows the summer noon illuminance of representative cities in regions one through five.

[0114] Table 2. Summer noon illuminance of representative cities in regions classified from Category I to Category V.

[0115]

[0116] At midday in summer, the strongest illuminance in most parts of China ranges from 80,000 to 154,000 lx. Since Class I regions in my country are primarily located in western Tibet and western Qinghai, characterized by flat plateau terrain, sparse populations, and limited transportation infrastructure (few tunnels), a Class II region illuminance value of 1.32 × 10⁻⁶ lx at midday on a sunny summer day can be considered. 5 lx is designed as a sunshade for the highest illuminance.

[0117] Design reference data for Class I areas: The illuminance at midday on a clear day in summer in Shigatse, Tibet, should be 1.54 × 10⁻⁶. 5 Around lx, actual measurement data shows that under the same illuminance difference, a smaller initial illuminance has a greater impact on the driver's reaction time. For example, the impact of an illuminance decrease from 120,000 lx to 80,000 lx on human vision is less than the impact of an illuminance decrease from 80,000 lx to 40,000 lx. The driver's reaction time is longer when the illuminance decreases from 60,000 lx to 2,000 lx than when it decreases from 120,000 lx to 6,200 lx. Because indoor tests cannot achieve 1.54 × 10⁻⁶ lx... 5 lx, where the illuminance difference that maximizes the fitting relationship is taken as 1.54 × 10. 5 The first gradient of lx reduction.

[0118] Substituting the initial illuminance x = 100000 lx into the dimming model, we obtain the maximum illuminance difference that satisfies visual adaptation safety as 67347 lx. Therefore, the illuminance difference of 67347 lx can be taken as the ambient illuminance of 1.54 × 10⁻⁶ lx. 5 The first illuminance gradient after reduction is calculated to be 86653 lx, and the light transmittance of the first section of the shade is calculated to be 60%. Substituting x=86653 lx into the dimming model and performing step-by-step calculations according to the process, it can be obtained that when the external illuminance is 1.54×10 5 The safe illuminance gradient model at lx is shown in Table 3.

[0119] Table 3 Reference Table for Dimming Model Design in Category I Areas

[0120]

[0121] Design reference data for Category II areas: The illuminance at noon on a sunny summer day in Urumqi, Xinjiang, is 1.32 × 10⁻⁶. 5 The illuminance is around lx, which is greater than the maximum simulated indoor illuminance. As mentioned above, the safe illuminance difference of 67347 lx when the initial illuminance x=100000 lx is taken as the first gradient of the environmental illuminance reduction. After calculation, the illuminance after reduction is 64653 lx, which meets the applicable range of the relation. Please see Table 4 for details.

[0122] Table 4 Reference Table for Dimming Model Design in Category II Areas

[0123]

[0124] Design reference data for Category III areas: The illuminance at noon on a sunny summer day in Jinan, Shandong Province, is 1.21 × 10⁻⁶. 5 The illuminance is around lx, which is greater than the maximum simulated indoor illuminance. As mentioned above, the safe illuminance difference of 67347 lx when the initial illuminance x=100000 lx is taken as the first gradient of the environmental illuminance reduction. After calculation, the illuminance after reduction is 53653 lx, which meets the applicable range of the relation. Please see Table 5 for details.

[0125] Table 5. Reference Table for Lighting Model Design in Three Types of Regions

[0126]

[0127] Design reference data for Category IV regions: The illuminance at noon on a sunny summer day in Lu'an, Anhui Province, is 1.0 × 10⁻⁶. 5 The illuminance is around lx, which meets the indoor simulated illuminance range. Please see Table 6 for details.

[0128] Table 6 Reference Table for Lighting Model Design in Four Types of Regions

[0129]

[0130] The design reference data for the five types of areas is as follows: the illuminance of Chongqing City in a sunny summer at noon is about 80,000 lx, which meets the indoor simulated illuminance range. Please see Table 7 for details.

[0131] Table 7. Reference Table for Dimming Model Design in Five Types of Regions

[0132]

[0133] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of the present invention.

[0134] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for constructing a tunnel sunshade based on a tunnel entrance dimming model, characterized in that, include: Step S1: In response to the preset illuminance conditions, collect illuminance test data for several target tunnels. For a single target tunnel, the measurement points include at least the normal ambient illuminance, the illuminance outside the entrance, the average illuminance at the entrance, the illuminance while driving inside the tunnel, the average illuminance at the exit, and the illuminance outside the exit. Step S2: Based on the illuminance test data and the SCANeR driving system, conduct human eye recognition reaction time tests on several target test subjects to obtain black hole effect test data and white hole effect test data under maximum illuminance-reaction time at several test vehicle speeds; the test vehicle speeds include 60km / h, 80km / h and 100km / h; Step S3: After performing nonlinear curve fitting analysis on the black hole effect test data and white hole effect test data respectively, obtain the correlation formula between the reaction time of the corresponding test vehicle speed and the maximum ambient illuminance: ， In the formula: T is the driver's reaction time; x0 is the maximum illuminance; y0, a1, a2, t1, and t2 are different constants under different conditions; Step S4: Perform a test on the safe illuminance gradient within the preset illuminance range to obtain an illuminance gradient fitting curve that satisfies the safe reaction time, and obtain the relationship between the initial illuminance value and the illuminance difference: ， In the formula: y is the illuminance difference, x is the initial illuminance value, and y3, a3 and t3 are different constants; Step S5, construct the dimming model according to the following formula: ， In the formula: y is the illuminance difference; x is the initial illuminance value; Step S6: Based on the dimming model, calculate the safe illuminance difference under the initial illuminance, calculate the light transmittance of each section of the sunshade, and calculate the design length of each section of the sunshade in sequence. The light transmittance of each section of the sunshade is calculated using the following formula: τ1=R / K, where τ1 is the light transmittance of the first section of the sunshade, R is the target reduction rate, and K is the geometric effective light transmittance coefficient of the first section of the sunshade; τ2 = I2 / (I2,in ×K2), where τ2 is the light transmittance of the second section of the sunshade, I2 is the illuminance of the second section of the sunshade after reduction, I2,in is the incident light intensity of the second section of the sunshade, and K2 is the geometric effective light transmittance coefficient of the second section of the sunshade. τn = In / (In,in ×Kn), where τn is the light transmittance of the nth segment of the sunshade, In is the illuminance of the nth segment of the sunshade after reduction, In,in is the incident light intensity of the nth segment of the sunshade, and Kn is the geometric effective light transmittance coefficient of the nth segment of the sunshade. For a single sunshade, K=K2=Kn; The design length of each section of the sunshade is calculated according to the following formula: Ln={ }×V, Where Ln is the design length of the nth sunshade segment, Rn is the target reduction rate of the nth sunshade segment, R1 is the target reduction rate of the 1st sunshade segment, and V is the most unfavorable speed limit for the highway tunnel, V=100km / h.

2. The method for constructing a tunnel sunshade based on a tunnel entrance dimming model according to claim 1, characterized in that, In step S2, the human eye recognition reaction time test includes: Step S201: Set the target contrast to 0.15; Step S202: Install an LED light above the front side of the driver's position in the SCANeR system driving simulation device. The maximum illuminance of the LED light is 120,000 lx. Step S203: Set the external illuminance of the LED lights in the tunnel to 120,000 lx, set the internal illuminance in the tunnel to 2,000 lx to 600 lx, and set the safe reaction time for the driver to 1.2s to 1.5s; Step S204: Select test subjects to conduct driving simulation tests to complete the human eye recognition reaction time test. Among them, the test with human eye recognition reaction time less than 100ms is retested, and the test data with human eye recognition reaction time greater than 4000ms is discarded.

3. The method for constructing a tunnel sunshade based on a tunnel entrance dimming model according to claim 2, characterized in that, In step S6, In response to the safe illuminance difference being greater than 2500 lx, the illuminance difference is recorded and substituted into the dimming model to obtain the safe illuminance difference again; In response to a safe illuminance difference of less than or equal to 2500 lx, the illuminance difference is recorded and the light transmittance of the corresponding section of the shade is calculated.

4. The method for constructing a tunnel sunshade based on a tunnel entrance dimming model according to claim 3, characterized in that, Also includes: Step S7: Obtain the illumination parameters of the preset area across the country, and divide the preset area into Class I to Class V areas according to the total annual solar radiation and the noon illumination on a sunny summer day. Step S8: Based on the dimming model, design reference data for regions from Class I to Class V are completed sequentially; The design reference data includes the light transmittance of each section of the sunshade and the design length of each section of the sunshade.

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