CN109969070B - Method for measuring and calculating traffic safety glare threshold of vehicle headlamp - Google Patents

Abstract

The invention discloses a method for measuring and calculating a traffic safety glare threshold value of a vehicle headlamp, which is characterized in that the influence degree of the headlamp glare on the safety vision of a driver is represented by the vertical illuminance generated by a light source of the vehicle headlamp at the eye position of the driver; the method comprises the following steps: 1) setting a background environment; 2) measuring headlamp light source characteristic data; 3) setting the relative position of the headlamp and the sight of a driver; 4) setting a safe visual perception glare grade scale; 5) the driver target object visually recognizes and measures the vertical illumination at the eye position of the driver; 6) resetting the relative position and angle of the headlamp and the sight line of the driver, and repeating the step 5); 7) and giving out a glare threshold value according to the obtained data processing result and the traffic safety glare three-dimensional influence area. The method provided by the invention is used for calculating the traffic safety glare of the vehicle headlamp on a road without illumination at night, and the light source characteristics, background environment factors, relative position factors and the safety visual recognition requirements of a driver of the vehicle headlamp are considered, so that a good basis is provided for the road anti-glare facility.

Description

A method for calculating the traffic safety glare threshold of vehicle headlights

technical field

The invention relates to the technical field of highway glare, in particular to a method for calculating a traffic safety glare threshold value of a road headlamp without illumination for driving at night.

Background technique

The height of the anti-glare facilities on the expressway is unreasonable, which directly affects the safety and comfort of driving at night. The height of the anti-glare facility is too high, although it has a good anti-glare effect, but the lateral field of view is insufficient, the space is very oppressive, and it is not economical; , it will cause the driver to have vision loss or even lose visual recognition in a short period of time, or cause traffic accidents due to stress. At this stage, the anti-glare technology is only simply designed based on the driver's visual height, the height of the lights, and the width of the driving lane on the straight road section.

At present, there are few researches on the traffic safety glare of vehicle headlights at home and abroad, most of which are based on the achievements in the field of road lighting glare, and there is no research on the characteristics of the headlight source and the safety visual recognition needs of drivers. The factors influencing the establishment of the glare threshold are not considered comprehensively, and there is no calculation method for the three-dimensional affected area of glare and the glare threshold.

SUMMARY OF THE INVENTION

The purpose of the present invention is to solve the defects of the existing anti-glare facility setting technology, and provide a reliable and easy-to-operate method for calculating the traffic safety glare threshold of road vehicle headlights without illumination at night, which involves the characteristics of light sources, headlights and The relative position of the driver's line of sight, background environmental factors, and the driver's safety visual recognition requirements are used to characterize the degree of influence of the headlight glare by the vertical illuminance at the driver's human eye, and a glare threshold measurement system is established.

The present invention provides a method for calculating the traffic safety glare threshold of vehicle headlights, comprising the following steps:

Step 1: Configure the background environment.

Step 2: Measure the characteristic data of the vehicle headlight source;

The characteristic data of the headlamp light source includes color temperature, maximum light intensity, and iso-illuminance curve.

Step 3: Set the relative position of the headlight and the driver's sight;

Adjust the relative position of the headlights and the driver, and obtain the conditions of the vehicle when driving on various linear sections such as concave vertical curves, convex vertical curves, flat curves, straight lines, and combined horizontal and vertical lines, and analyze the relationship between relative position and angle factors. The effect of glare;

The relative position of the headlamp and the driver includes the angle, longitudinal distance, lateral distance, and vertical distance between the headlamp and the driver's line of sight.

Step 4: Set the safety visual recognition glare level scale;

Combined with the physiological stress response of the driver's safety visual recognition by different degrees of influence of glare during driving, glare is divided into two levels: glare level 1 - interference glare, and glare level 2 - allowable glare.

Step 5: Visual recognition of the driver's target and measurement of the vertical illuminance at the driver's eye position;

Place a small target on the road 110m in front of the driver's visual position. The small target has a gray cube with a surface reflection coefficient of 0.2 and a side length of 20cm;

Perform visual recognition of the target to obtain the maximum light intensity point, the reference line, and the "interference-tolerance" reference point. The visual recognition steps include:

1) Adjust the center line of the headlamp to a horizontal position, and the light beam falls naturally;

2) The driver adapts to the background environment for 10 minutes;

3) Select a longitudinal section, and the driver looks straight ahead and moves up and down under this longitudinal distance, finds the height with the strongest glare and records it, and the horizontal line where this height is located is the reference line;

4) The driver moves to the right at the height of the reference line, and the moving distance is recorded as the horizontal distance; according to the safety visual recognition glare level scale, determine the boundary point of glare level 1 and glare level 2, record it as the "interference-tolerance" reference point, measure And record the vertical illuminance data at the human eye position at this point;

5) According to the horizontal distance of the "interference-tolerance" reference point, determine the iso-illuminance curve where the reference point is located in this longitudinal section;

6) The driver determines the position of each point in the "interference-tolerable" glare level near the iso-illuminance curve, measures and records the vertical illuminance data at the human eye position at each point, and connects the points to obtain the "interference-tolerable" glare level dividing line ;

7) Repeat the steps 3) to 6) for visual recognition by resetting the longitudinal section;

8) To reset the relative position, repeat the steps 3) to 7) for visual recognition.

Step 6: Obtain the glare threshold;

Process and analyze the collected visual recognition data under the "interference-tolerable" glare level to obtain the "interference-tolerable" glare plane influence area of each longitudinal section; by processing the glare plane influence area data of different longitudinal sections, A three-dimensional influence area of glare at relative positions is obtained; using the same data processing method, the three-dimensional influence area of glare at different relative positions is obtained;

The measured illuminance data of the "interference-tolerable" glare grade boundary line are processed and analyzed to obtain the glare thresholds of vehicle headlamps with different longitudinal distances.

The background environment described in step 1 is an unilluminated road driving environment at night.

The angle is the angle between the main optical axis of the headlamp and the driver's line of sight; the longitudinal distance (longitudinal distance) is the straight line distance between the headlamp and the driver along the direction of the main optical axis, and the cross section where the longitudinal distance is located is the vertical distance. Distance section; for the same longitudinal section, the distance moved in the horizontal direction from the maximum light intensity point is the horizontal distance (horizontal distance); for the same longitudinal section, the distance moved in the vertical direction from the maximum light intensity point is the vertical distance (vertical distance).

The angle between the headlight and the driver's line of sight described in step 3 is that the headlight is turned upward by 2° to 8°, downward by 2° to 8°, and turned left by 3° to 12°.

The physiological stress response of the driver when the driver is affected by the glare in step 4 refers to that the driver's eyes are lowered or the ability to observe objects and details is lost when the driver is affected by the glare.

The maximum point of light intensity described in step 5 is the point where the driver's eyes are located in a longitudinal section when the driver is most affected by glare;

The "interference-tolerance" reference point is the position of the junction point between the interference glare and the allowable glare level on the reference line.

The "disability-interference" reference point and the "interference-tolerance" reference point in step 5 are the points on the baseline where the visual recognition and perception of the disability glare and the interference glare, and the interference glare and the allowable glare meet.

The area included in the "interference-tolerable" glare grade boundary line in step 5 6) is the area affected by the interference glare.

The "interference-tolerance" glare plane influence area described in step 6 adopts the accumulated 85% of the drivers to accept the glare influence of this point as the reference point, and finds the glare plane influence area of the longitudinal section based on the reference point;

The three-dimensional glare-affected area refers to the area where the driver's safety visual recognition requirement is affected by the glare of the vehicle headlight when the driver's sight line is within the three-dimensional area.

Compared with the prior art, the present invention has the following obvious advantages and beneficial effects:

The invention provides a method for calculating the traffic safety glare threshold value of vehicle headlights, which determines the main influencing factors of the traffic safety glare of the headlights by analyzing the generation mechanism of the driver's glare caused by the headlight source of the opposite vehicle on the unilluminated road at night; Drivers have psychological stress response when they are affected by glare, and a glare level scale for safety visual recognition of facing headlights is proposed. Combined with the characteristics of the light source, the relative position of the headlamp and the driver's line of sight, and the background environmental factors, the driver's driving safety visual recognition requirements are used, and the vertical illuminance at the driver's eye position is used to measure the degree of influence of the headlamp glare. Through the processing and analysis of a large number of sample data, the three-dimensional influence area and glare threshold of glare under different relative positions are obtained.

Because the three-dimensional impact area of glare determines the area where the driver's safety visual recognition needs are affected by the glare of the vehicle headlights, the glare threshold is accurately given, which provides a good basis for the setting of road anti-glare facilities.

Description of drawings

Further objects, functions and advantages of the present invention will be elucidated by the following description of embodiments of the present invention with reference to the accompanying drawings, wherein:

Fig. 1 is the flow chart of the preferred embodiment of the method for measuring the traffic safety glare of the headlamp according to the present invention;

Figure 2 is a schematic diagram of the relative spectral power distribution of the headlamp;

Figure 3 is a schematic diagram of an iso-illuminance curve of a headlamp;

Fig. 4 is a schematic diagram of visual recognition of small objects;

Figure 5 is a schematic view of cross-sectional view at different longitudinal distances;

Figure 6 is a schematic view of a longitudinal section

Figure 7 is a schematic diagram of the area affected by the horizontal 10m glare plane;

Figure 8 is a schematic diagram of the area affected by the 4°7m glare plane;

9 is a schematic diagram of a three-dimensional influence area of horizontal angle glare;

Detailed ways

In order to enable those skilled in the art to better understand the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only the Some, but not all, embodiments are disclosed. Based on the embodiments in the invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

Fig. 1 shows a flow chart of a preferred embodiment of the method for measuring the traffic safety glare of a headlamp according to the present invention. In combination with the characteristics of the headlamp source, the relative position of the headlamp and the driver's line of sight, and background environmental factors, the driver's safety vision According to the recognition requirements, the vertical illuminance at the driver's eye position is used to represent the degree of influence of the traffic safety glare of the headlights. The following steps are used to complete the establishment of the glare threshold measurement system:

Step 1: Configure a background environment, where the background environment is an unilluminated road driving environment at night.

When the vehicle is driving at night on an unilluminated road, the driver only relies on the beam of the headlight to observe the road conditions and the linear direction ahead. The light source of the headlight forms a strong brightness contrast with the dark environment at night, which is the period when the glare of the headlight is frequent. .

Step 2: Measure the characteristic data of the vehicle headlamp light source, where the characteristic data of the headlamp light source include color temperature, maximum light intensity, luminous flux, relative spectral power distribution, and iso-illuminance curve. The characteristics of the light source itself, such as brightness, color temperature, and spectrum, determine the degree of glare's influence on the human eye. The glare is mostly caused by the brightness of the light source. The larger the surface area of the light source, the greater the brightness of the light source, and the stronger the glare; blue cone light The apparent efficiency function has an obvious linear correlation with the uncomfortable glare level. The higher the color temperature, the more blue light, which is more likely to make the observer feel uncomfortable. The relative spectral power distribution diagram and the isoilluminance curve are shown in Figures 2 and 3.

Step 3: Set the relative position of the headlight and the driver's line of sight, including the angle, vertical distance, horizontal distance, and vertical distance between the main optical axis of the headlight and the driver's line of sight. With the change of the line shape, the angle between the human eye sight and the main optical axis of the glare source also changes; the difference in distance leads to the difference in the brightness of the light beam entering the human eye; The driving lane also affects the driver's visual recognition. These are physical quantities that reflect the relative position of the glare source and the eyes. The closer the light source is to the eye and the smaller the angle between the main optical axis and the line of sight, the stronger the glare. By changing the relative position, it simulates the driving situation of vehicles on special linear road sections such as flat curves, straight lines, concave vertical curves, convex vertical curves, and combined horizontal and vertical sections, and analyzes the influence of relative position and angle factors on glare.

The angle between the headlight and the driver's line of sight is that the headlight is turned upward by 2°, 4°, 6°, and 8°, turned downward by 2°, 4°, 6°, and 8°, and turned left by 3°. °, 6°, 9°, 12°; the longitudinal distance values are 3m, 5m, 7m, 10m, 12m, 15m, 30m, 50m, 70m, 100m, 120m.

Step 4: Set the safety visual recognition glare level scale. Avoiding glare is a necessary condition to meet the driver's safe visual recognition of driving. When the glare is stimulated, a physiological stress response will occur, which will make the driver reduce or lose the ability to observe objects and details. ; Combining the individual differences in visual recognition experiments and the understanding of the meaning of glare, glare is divided into two levels: glare level 1 - interference glare, glare level 2 - allowable glare.

Place a small target on the road 110m in front of the driver's visual recognition position. The visual recognition target is a 20cm*20cm*20cm gray cube (low contrast) recommended by the International Lighting Association, the surface reflection coefficient is 0.2, and the color is similar to the background road ,As shown in Figure 4.

Table 1 is the safety visual recognition glare level scale

Step 5: Visual recognition of the driver's target and measurement of the vertical illuminance at the driver's eye position. Change the angle between the headlight and the driver, and visually recognize the longitudinal section at different longitudinal distances, as shown in Figure 5. In different horizontal and vertical distances of the same vertical section, the affected area of the interference glare is searched by visual recognition. The affected area is the area included in the "interference-tolerance" boundary line. The boundary line is composed of a boundary point and a reference point. The "interference-tolerance" reference point is the point with the largest horizontal distance on the boundary line. The distance is also the vertical distance of the point with the maximum light intensity. A vertical distance section is visually recognized as shown in Figure 6 below. It is known from the iso-illuminance curve that the farther the same section is from the main optical axis, the slower the illuminance decreases. In order to avoid the small change of illuminance in the section with a long longitudinal distance, which will cause the driver's visual recognition difference to be too large and affect the accuracy, it is decided to determine the position of the horizontal "interference-tolerance" reference point and illuminance information, the position of other points on the dividing line Look for it near the iso-illuminance curve where the reference point is located, and the driver adjusts and confirms the visual perception at this position.

The visual recognition steps include: 1) adjusting the center line of the headlight fixture to a horizontal position, and the light beam falls naturally; 2) the driver adapts to the background environment for 10 minutes; 3) selects a longitudinal section, where the driver is vertically Look straight ahead and move up and down from the distance, find the height with the strongest glare and record it. The horizontal line where this height is located is the reference line; 4) The driver moves to the right at the height of the reference line, and the moving distance is recorded as the horizontal distance; The glare level scale determines the demarcation point between glare level 1 and glare level 2, and records it as the "interference-tolerance" reference point, and measures and records the vertical illuminance data at the human eye position at this point; 5) According to the "interference-tolerance" reference point Horizontal distance, determine the iso-illuminance curve where the reference point is located in the vertical distance section; 6) The driver determines the position of each point in the "interference-tolerable" glare level near the iso-illuminance curve, and measures and records the position of the human eye at each point. For vertical illuminance data, connect each point to get the “interference-tolerance” glare level dividing line; 7) reset the vertical section and repeat 3) to 6) visual recognition steps; 8) reset the relative position and repeat 3) to 7) visual recognition steps;

Step 6: Obtain the glare threshold; process and analyze the collected visual recognition data, and use the cumulative 85% of the drivers to accept the glare effect of this point as the "interference-tolerance" reference point. A "interference-tolerable" glare plane influence area of a longitudinal section, as shown in Figures 7 and 8; by processing the data of the glare plane influence area of different longitudinal sections, the standard "interference-tolerable" glare level of a 10m longitudinal section is obtained Demarcation line, based on this demarcation line, calculate the glare demarcation line from 1m to 120m at the horizontal angle, and obtain the three-dimensional influence area of glare; use the same data processing method to obtain the three-dimensional influence area of glare at different relative positions;

The measured illuminance data are processed and analyzed, according to the inverse square theorem of illuminance, and combined with the linear relationship with the light intensity at the light source, the glare thresholds of different longitudinal sections are obtained.

Table 2 is the horizontal angle glare threshold

Table 3 shows the glare thresholds for different angles of the 5m longitudinal section

Through the method of this embodiment, the relationship between the degree of glare influence and the relative position, the characteristics of the headlight source, and the background environment is established. The threshold value provides an effective and reasonable guide standard for the setting method of highway anti-dazzle facilities to meet the needs of drivers' safety and comfort visual recognition.

Claims (8)

1. a method for calculating a vehicle headlight traffic safety glare threshold, characterized in that it comprises the following steps: Step 1: Configure the background environment; The background environment is an unilluminated road driving environment at night; Step 2: Measure the characteristic data of the vehicle headlight source; The characteristic data of the headlamp light source includes color temperature, maximum light intensity, and iso-illuminance curve; Step 3: Set the relative position of the headlight and the driver's sight; Adjust the relative position of the headlight and the driver to obtain the vehicle driving conditions on various linear sections of concave vertical curve, convex vertical curve, flat curve, straight line, and combined horizontal and vertical lines, and analyze the relative position and angle factors on glare Impact; The relative position of the headlamp and the driver includes the angle, longitudinal distance, lateral distance, and vertical distance between the headlamp and the driver's line of sight; Step 4: Set the safety visual recognition glare level scale; Combined with the physiological stress response of the driver's safety visual recognition by different degrees of influence of glare during driving, glare is divided into two levels: glare level 1 - interference glare, glare level 2 - allowable glare; Step 5: Visual recognition of the driver's target and measurement of the vertical illuminance at the driver's eye position; Place a small target on the road 110m in front of the driver's visual recognition position, perform visual recognition of the target, and obtain the maximum light intensity point, reference line, and interference-allowance reference point. The visual recognition steps include: 1) Adjust the center line of the headlamp to a horizontal position, and the light beam falls naturally; 2) The driver adapts to the background environment for more than 10 minutes; 3) Select a longitudinal section, and the driver looks straight ahead and moves up and down under this longitudinal distance, finds the height with the strongest glare and records it, and the horizontal line where this height is located is the reference line; 4) The driver moves to the right at the height of the reference line, and the moving distance is recorded as the horizontal distance; according to the safety visual recognition glare level scale, determine the boundary point of glare level 1 and glare level 2, record it as the interference-allowance reference point, measure and record Interference - vertical illuminance data at the human eye position of the allowable reference point; 5) According to the horizontal distance of the interference-allowable reference point, determine the isoilluminance curve where the reference point is located in this vertical distance section; 6) The driver determines the position of each point in the interference-allowable glare level within the range of 0-30cm near each point on the iso-illuminance curve, measures and records the vertical illuminance data at the human eye position at each point, and connects the points to obtain interference-allowable. Glare grade dividing line; 7) Repeat the steps 3) to 6) for visual recognition by resetting the longitudinal section; 8) Re-set the relative position and repeat 3) to 7) visual recognition steps; Step 6: Obtain the glare threshold; The collected interference-allowable glare visual recognition data under the level of glare are processed and analyzed to obtain the interference-allowable glare plane influence area of each longitudinal section; The three-dimensional influence area of glare at relative positions; the same data processing method is used to obtain the three-dimensional influence area of glare at different relative positions; The illuminance data of the measured interference-allowable glare level dividing line are processed and analyzed to obtain the glare thresholds of different longitudinal sections of vehicle headlamps. 2. The method for measuring a vehicle headlamp traffic safety glare threshold according to claim 1, wherein: The angle is the angle between the main optical axis of the headlamp and the driver's line of sight; the longitudinal distance is the straight line distance between the headlamp and the driver along the direction of the main optical axis, and the transverse section where the longitudinal distance is located is the longitudinal section; the same For longitudinal section, the distance moved in the horizontal direction from the point of maximum light intensity is the horizontal distance; for the same longitudinal section, the distance moved in the vertical direction from the point of maximum light intensity is the vertical distance. 3. The method for calculating a vehicle headlight traffic safety glare threshold according to claim 1, wherein: The angle between the headlight and the driver's line of sight described in step 3 is that the headlight is turned upward by 2° to 8°, downward by 2° to 8°, and turned left by 3° to 12°. 4. The method for calculating a vehicle headlamp traffic safety glare threshold according to claim 1, wherein: The physiological stress response of the driver when the driver is affected by the glare in step 4 refers to that the driver's eyes are lowered or the ability to observe objects and details is lost when the driver is affected by the glare. 5. The method for calculating a vehicle headlamp traffic safety glare threshold according to claim 1, wherein: The small target in step 5 is a gray cube with a surface reflection coefficient of 0.2, and a side length of 20 cm. 6. The method for calculating a vehicle headlamp traffic safety glare threshold according to claim 1, wherein: The maximum point of light intensity described in step 5 is the point where the driver's eyes are located in a longitudinal section when the driver is most affected by glare; The interference-tolerable reference point is the position of the junction point between the interference glare and the allowable glare level on the reference line. 7. The method for calculating a vehicle headlamp traffic safety glare threshold according to claim 1, wherein: The area included in the boundary line of the interference-allowable glare level in step 5 6) is the affected area of the interference glare. 8. The method for calculating a vehicle headlamp traffic safety glare threshold according to claim 1, wherein: The interference-allowable glare plane influence area described in step 6 adopts the point at which 85% of the drivers can accept the glare influence as the reference point, and finds the glare plane influence area corresponding to the longitudinal section based on the reference point; The glare three-dimensional affected area refers to the area where the driver's safety visual recognition needs are affected by the glare of the vehicle headlights when the driver's line of sight is in the three-dimensional area.

Images