A real-time monitoring device and method for retroreflective coefficient

Abstract

A retroreflective coefficient real-time monitoring device and method, a base is equipped with a pose adjuster, the pose adjuster is equipped with light source module, retroreflective light receiving optical device respectively, the pose adjuster is used for adjusting the spatial pose of light source module and retroreflective light receiving optical device, makes the outgoing light spot of light source module fall in the retroreflective light receiving optical device of the retroreflective light of the measured surface of reflecting facility formation; The output end of the photometric data acquisition module of retroreflective light receiving optical device is connected with optical analysis display component; Photometric data acquisition module is composed of parallel binocular vision imaging detector and illumination detector, binocular vision imaging detector collects microsecond level high speed brightness at the measured surface of reflecting facility, and the vertical illumination value of the measured surface of reflecting facility is collected by illumination detector; Optical analysis display component processes the data collected by photometric data acquisition module through built-in retroreflective coefficient calculation formula, and obtains retroreflective coefficient measurement result.

Description

Technical Field

[0001] This invention belongs to the technical field of testing or analyzing materials by measuring their chemical or physical properties, and specifically relates to a device and method for real-time monitoring of retroreflection coefficient. Background Technology

[0002] Retroreflective materials are crucial for road traffic safety (such as signs, markings, raised pavement markers, and warning vests), and the accurate measurement of their core performance indicator—the retroreflection coefficient—is fundamental to ensuring road traffic safety. The retroreflection coefficient is an optical physical quantity that measures the ability of a retroreflective material to redirect light back towards the source under illumination. It is an internationally recognized key indicator of the performance of reflective safety facilities. Research shows that the retroreflection coefficient directly determines the visibility of traffic safety facilities at night or in low-light conditions. The higher the retroreflection coefficient, the brighter and clearer the signs and markings are under vehicle headlights, allowing drivers to spot and identify them earlier, thus significantly improving road safety. Therefore, transportation departments in various countries use it as a mandatory standard for product quality testing and facility maintenance assessment.

[0003] The technical indicators for evaluating the retroreflective performance of different types of road traffic reflective safety facilities (retroreflective signs, retroreflective markings, and raised pavement markers) vary. According to the relevant provisions of the National Metrological Technical Specification JJF 1976-2020 "Calibration Specification for Retroreflective Standards," the retroreflective values ​​of road retroreflective signs, retroreflective markings, and raised pavement markers are respectively expressed using the retroreflection coefficient Rreflection. A Retroreflection luminance coefficient R L and luminous intensity coefficient R I To evaluate this, there are currently two main methods for measuring retroreflectivity: one is static high-precision measurement in a laboratory, but this requires sending the sample to a specialized laboratory for testing, which is technically demanding and inefficient, failing to meet the needs of on-site and online road measurements; the other is portable on-site testing, but limited by digital image processing technology, such devices are mostly single-point, static measurements with limited accuracy, making it difficult to achieve large-scale, continuous road network condition surveys and real-time monitoring. Therefore, developing a high-precision, portable real-time retroreflectivity monitoring device to achieve high-precision continuous evaluation of the performance of reflective facilities across the entire road network is of significant importance for ensuring road traffic safety. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a real-time retroreflection coefficient monitoring device that is compact in structure, small in size, and accurate in measurement.

[0005] The technical solution adopted to solve the above technical problems is: a retroreflection coefficient real-time monitoring device, wherein a pose adjuster is provided on the base, and a light source module and a retroreflection light receiving optical device are respectively installed on the pose adjuster. The pose adjuster is used to adjust the spatial attitude of the light source module and the retroreflection light receiving optical device so that the light spot emitted by the light source module falls on the surface to be tested of the reflective facility, and the retroreflected light formed on the surface to be tested of the reflective facility enters the retroreflection light receiving optical device.

[0006] The retroreflective light receiving optical device is an optical resolution display component connected to the output end of the photometric data acquisition module.

[0007] The photometric data acquisition module consists of a binocular vision imaging detector and an illuminance detector connected in parallel. The binocular vision imaging detector is used to acquire the microsecond-level high-speed brightness of the light emitted from the light source illuminating the surface to be measured of the reflective facility. The illuminance detector is used to acquire the vertical illuminance value of the light source module at the surface to be measured of the reflective facility.

[0008] The optical analysis and display component processes the data acquired by the photometric data acquisition module using the built-in retroreflection coefficient calculation formula to obtain and display the retroreflection coefficient measurement result.

[0009] As a preferred technical solution, the base is a fixed platform or a mobile platform.

[0010] As a preferred technical solution, the binocular vision imaging detector includes a transient detection module and a calibration and verification module. The transient detection module is used to detect changes in brightness in the area to be measured at the microsecond level, and the calibration and verification module is used to provide reference brightness data for the transient detection module and perform verification.

[0011] As a preferred technical solution, the transient detection module includes an imaging optical unit, a pixel array unit, a brightness change detection unit, a threshold determination unit, a polarity determination unit, a timestamp generation unit, an address encoding unit, and a data output unit;

[0012] The imaging optical unit is used to image the scene under test onto the pixel array unit;

[0013] The pixel array unit contains multiple independent pixel channels, each pixel channel being used to convert the received optical signal into a voltage signal and output it.

[0014] The brightness change detection unit is used to compare the current voltage signal of each pixel channel with the voltage signal at the previous moment and output the voltage change amount.

[0015] The threshold determination unit is used to compare the voltage change of each pixel channel with a preset threshold to determine whether the triggering condition is met. When the voltage change is ≥ the positive preset threshold or the voltage change is ≤ the negative preset threshold, it is determined to be a valid event.

[0016] The polarity determination unit determines the polarity p of the brightness change based on valid events. If the voltage change is greater than or equal to a positive preset threshold, the brightness increases and the polarity is positive. If the voltage change is less than or equal to a negative preset threshold, the brightness decreases and the polarity is negative.

[0017] The timestamp generation unit is used to record the occurrence time t for each valid event;

[0018] The address encoding unit is used to output the pixel position coordinates (x, y) for each valid event;

[0019] The data output unit is used to output the event data η=(x, y, t, p) representing the brightness change process of each pixel channel to the optical resolution display component.

[0020] As a preferred technical solution, the posture adjuster has a base with a column, a height-adjustable mounting plate on the column, two multi-joint connecting arms on the mounting plate, and mounting heads at the ends of the multi-joint connecting arms.

[0021] As a preferred technical solution, the output terminal of the optical resolution display component is also connected to an early warning module, which is used to generate an alarm when the measurement result exceeds the safety threshold.

[0022] The present invention also provides a method for monitoring the retroreflection coefficient using a real-time retroreflection coefficient monitoring device, characterized by comprising the following steps:

[0023] Step 1. Determine the evaluation index of retroreflection coefficient for different types of reflective facilities according to the national metrological technical specification "Calibration Specification for Retroreflective Standards";

[0024] Step 2. Analyze and evaluate the indicators to determine the basic measurement parameters for real-time monitoring of retroreflection coefficient based on the luminance method;

[0025] Step 3. Adjust the spatial orientation of the light source module and the photometric data acquisition module to ensure that the incident angle, observation angle, and viewing angle meet the requirements of the "Calibration Specification for Retroreflective Standard".

[0026] Step 4. Obtain the brightness data and effective light-receiving area parameters reflected back to the observer's eyes by the binocular vision imaging detector in the photometric data acquisition module; obtain the vertical illuminance values ​​of the light source module at different types of road traffic reflective safety facilities by the illuminance detector in the photometric data acquisition module.

[0027] Step 5. The optical analysis display component outputs the retroreflection coefficient measurement value in real time based on the retroreflection coefficient calculation formula in the "Retroreflection Standard Calibration Specification". If the measurement value exceeds the safety threshold, the warning module will issue an alarm.

[0028] As a preferred technical solution, the reflective device in step 1 is a road retroreflective sign, using a retroreflection coefficient R. A As an evaluation indicator

[0029]

[0030] In the formula, The brightness of the road retroreflective sign reflected back to the observer's eye. The vertical illuminance of the light source module at the reference center of the road retroreflective sign surface to be measured;

[0031] In step 2, the basic measurement parameter is: the brightness of the road retroreflective sign reflected back to the observer's eye. Vertical illuminance of the light source module at the reference center of the road retroreflective sign surface to be measured. ;

[0032] In step 3, the incident angle is the angle between the optical axis of the light source module and the normal to the center of the area to be measured of the road retroreflection sign. The observation angle is the angle between the center normal of the transient detection module and the optical axis of the light source module. ;

[0033] The specific operation of step 4 is as follows:

[0034] Step 4.1. Start the preheating of the light source module. After preheating, the illuminance detector measures the illuminance value perpendicular to the optical axis at a distance l0 from the light-emitting surface of the light source module. The diameter of the light spot at 10 locations was measured using a ruler. ;

[0035] Step 4.2. Illuminate the surface of the road retroreflective sign with the light emitted from the light source module to form the light spot area of ​​the retroreflective sign to be tested;

[0036] Step 4.3. Set the brightness change criterion parameters for each pixel in the transient detection module. Set the aperture, exposure time, and frame rate of the calibration and verification module;

[0037] Step 4.4. Adjust the attitude of the binocular vision imaging detector so that the light spot is clearly imaged at the center of the field of view of the transient detection module and the calibration verification module, and record the distance l between the light spot and the light-emitting surface of the light source module at this time. A ;

[0038] Step 4.5. Extract the spot area within the field of view of the calibration and verification module using an image segmentation algorithm. Calculate the brightness value of each pixel in the spot area based on the grayscale value of each pixel and the response curve function obtained from laboratory calibration. Take the average value as the initial brightness value L. 0，A ;

[0039] Step 4.6. Extract the light spot region within the field of view of the transient detection module using an image segmentation algorithm. Take the average value of the voltage values ​​of each pixel in the light spot region as the initial voltage value V. 0，A Using the initial brightness value L 0，A For the initial voltage value V 0，A Perform the assignment and calibration;

[0040] Step 4.7. Based on the imaging size of the light spot on the transient detection module, count the number of pixels m along the minor axis. A The minor axis length D(l) of the light spot within the field of view of the transient detection module is obtained according to the following formula. A ),

[0041]

[0042] In the formula, e is the pixel equivalent of the transient detection module;

[0043] The vertical illuminance at the reference center of the light spot for:

[0044]

[0045] Step 4.8. Each pixel in the transient detection module independently monitors the retroreflection marker spot area in real time. When a pixel detects a brightness change exceeding the threshold M, it outputs event data η = (x, y, t, p) to the optical resolution display component and updates the reference signal of that pixel. The threshold M is equal to the basic amount of voltage change detected by the pixel channel, M = k is the gain coefficient of the transient detection module;

[0046] Step 4.9. The optical resolution display component counts the data stream feedback from each pixel in the spot area every g seconds. The frame rate f of the calibration verification module is an integer multiple of the time interval g. The average voltage V of each pixel in the spot area at the z-th statistical time is... z，A for:

[0047]

[0048] In the formula, For the light spot area Each pixel channel; This represents the total number of pixel channels in the light spot area. For the first The pixel channel The feedback data; q is the first data point within g seconds. The total number of feedback data per pixel channel; For the first Each pixel channel detects the basic voltage change;

[0049] The average brightness value L of the light spot area at the z-th statistical time point z，A for:

[0050]

[0051] Step 4.10. The calibration and verification module periodically measures the average brightness at a low frame rate f. If the two measurements are inconsistent, the value of the calibration and verification module is used as the standard for correction to achieve self-calibration.

[0052] In step 5, the specific operation of the optical resolution display component in outputting the retroreflection coefficient measurement value in real time based on the retroreflection coefficient calculation formula in the "Retroreflection Standard Calibration Specification" is as follows:

[0053] The average brightness value L of the retroreflection marker spot area to be measured at the z-th statistical time obtained in step 4 is used. z，A Vertical illuminance at the reference center of the light spot Substituting into the formula for the retroreflection coefficient, we obtain the retroreflection coefficient R at the z-th statistical time. z，A .

[0054] As a preferred technical solution, the reflective device in step 1 is a retroreflective marker, using a retroreflective brightness coefficient R. L As an evaluation indicator

[0055]

[0056] In the formula, The brightness of the retroreflective marker reflected back to the observer's eye. From the perspective of The vertical illuminance of the light source module at the reference center of the retroreflective surface to be measured;

[0057] In step 2, the basic measurement parameter is: the brightness of the retroreflective marker reflected back to the observer's eye. The vertical illuminance of the light source module at the reference center of the retroreflective surface to be measured. Perspective ;

[0058] In step 3, the incident angle is the angle between the optical axis of the light source module and the normal to the center of the area to be measured by the retroreflection marker. The observation angle is the angle between the center normal of the transient detection module and the optical axis of the light source module. perspective ;

[0059] The specific operation of step 4 is as follows:

[0060] Step 4.1. Start the preheating of the light source module. After preheating, the illuminance detector measures the illuminance value perpendicular to the optical axis at a distance l0 from the light-emitting surface of the light source module. The diameter of the light spot at 10 locations was measured using a ruler. ;

[0061] Step 4.2. Illuminate the surface of the retroreflective marking with the light emitted from the light source module to form a light spot area of ​​the retroreflective marking to be tested;

[0062] Step 4.3. Set the brightness change criterion parameters for each pixel in the transient detection module. Set the aperture, exposure time, and frame rate of the calibration and verification module;

[0063] Step 4.4. Adjust the attitude of the binocular vision imaging detector so that the light spot is clearly imaged at the center of the field of view of the transient detection module and the calibration verification module, and record the distance l between the light spot and the light-emitting surface of the light source module at this time. L ;

[0064] Step 4.5. Extract the spot area within the field of view of the calibration and verification module using an image segmentation algorithm. Calculate the brightness value of each pixel in the spot area based on the grayscale value of each pixel and the response curve function obtained from laboratory calibration. Take the average value as the initial brightness value L. 0，L ;

[0065] Step 4.6. Extract the light spot region within the field of view of the transient detection module using an image segmentation algorithm. Take the average value of the voltage values ​​of each pixel in the light spot region as the initial voltage value V. 0，L Using the initial brightness value L 0，L For the initial voltage value V 0，L Perform the assignment and calibration;

[0066] Step 4.7. Based on the imaging size of the light spot on the transient detection module, count the number of pixels m along the minor axis. L The minor axis length D(l) of the light spot within the field of view of the transient detection module is obtained according to the following formula. L ),

[0067]

[0068] In the formula, e is the pixel equivalent of the transient detection module;

[0069] The vertical illuminance at the reference center of the light spot for:

[0070]

[0071] Step 4.8. Each pixel in the transient detection module independently monitors the retroreflective marker spot area in real time. When a pixel detects a brightness change exceeding the threshold M, it outputs event data η = (x, y, t, p) to the optical resolution display component and updates the reference signal of that pixel. The threshold M is equal to the basic value of the voltage change detected by the pixel channel, M = k is the gain coefficient of the transient detection module;

[0072] Step 4.9. The optical resolution display component counts the data stream feedback from each pixel in the spot area every g seconds. The frame rate f of the calibration verification module is an integer multiple of the time interval g. The average voltage of each pixel in the spot area at the z-th statistical time is... for:

[0073]

[0074] In the formula, For the light spot area Each pixel channel; This represents the total number of pixel channels in the light spot area. For the first The pixel channel The feedback data; q is the first data point within g seconds. The total number of feedback data per pixel channel; For the first Each pixel channel detects the fundamental amount of voltage change;

[0075] The average brightness value L of the light spot area at the z-th statistical time point z，L for:

[0076]

[0077] Step 4.10. The calibration and verification module periodically measures the average brightness at a low frame rate f. If the two measurements are inconsistent, the value of the calibration and verification module is used as the standard for correction to achieve self-calibration.

[0078] In step 5, the specific operation of the optical resolution display component in outputting the retroreflection coefficient measurement value in real time based on the retroreflection coefficient calculation formula in the "Retroreflection Standard Calibration Specification" is as follows:

[0079] The parameters obtained in step 4 are the average brightness value L of the retroreflective marking spot area to be measured at the z-th statistical time. z，L Vertical illuminance at the reference center of the light spot Substituting into the formula for the retroreflection coefficient, we obtain the retroreflection coefficient R at the z-th statistical time. z，L .

[0080] As a preferred technical solution, the reflective device in step 1 is a raised pavement marker, employing a luminous intensity coefficient... As an evaluation indicator

[0081]

[0082] In the formula, S is the effective light-receiving area of ​​the surface of the raised pavement marker to be tested. The brightness reflected back to the observer's eye from the protruding road sign. The vertical illuminance of the light source module at the reference center of the surface to be measured on the protruding road sign;

[0083] In step 2, the basic measurement parameter is: the brightness of the reflection of the raised road sign back to the observer's eye. Vertical illuminance of the light source module at the reference center of the surface to be measured on the raised road sign Perspective ;

[0084] In step 3, the incident angle is the angle between the optical axis of the light source module and the normal to the center of the area to be measured of the protruding landmark. The observation angle is the angle between the center normal of the transient detection module and the optical axis of the light source module. perspective ;

[0085] The specific operation of step 4 is as follows:

[0086] Step 4.1. Start the preheating of the light source module. After preheating, the illuminance detector measures the illuminance value perpendicular to the optical axis at a distance l0 from the light-emitting surface of the light source module. The diameter of the light spot at 10 locations was measured using a ruler. ;

[0087] Step 4.2. Illuminate the surface of the raised pavement with the light emitted from the light source module to form a light spot area of ​​the raised pavement to be tested;

[0088] Step 4.3. Set the brightness change criterion parameters for each pixel in the transient detection module. Set the aperture, exposure time, and frame rate of the calibration and verification module;

[0089] Step 4.4. Adjust the attitude of the binocular vision imaging detector so that the light spot is clearly imaged at the center of the field of view of the transient detection module and the calibration verification module, and record the distance l between the light spot and the light-emitting surface of the light source module at this time. I ;

[0090] Step 4.5. Extract the spot area within the field of view of the calibration and verification module using an image segmentation algorithm. Calculate the brightness value of each pixel in the spot area based on the grayscale value of each pixel and the response curve function obtained from laboratory calibration. Take the average value as the initial brightness value L. 0，I ;

[0091] Step 4.6. Extract the light spot region within the field of view of the transient detection module using an image segmentation algorithm. Take the average value of the voltage values ​​of each pixel in the light spot region as the initial voltage value V. 0，I Using the initial brightness value L 0，I For the initial voltage value V 0，I Perform the assignment and calibration;

[0092] Step 4.7. Based on the imaging size of the light spot on the transient detection module, count the number of pixels m along the minor axis. I and the number of pixels n along the major axis I The minor axis length D(l) of the light spot within the field of view of the transient detection module is obtained according to the following formula. I ),

[0093]

[0094] In the formula, e is the pixel equivalent of the transient detection module;

[0095] The vertical illuminance at the reference center of the light spot for:

[0096]

[0097] The effective light-receiving area S of the surface to be tested on the raised pavement marker is:

[0098]

[0099] Step 4.8. Each pixel of the transient detection module independently monitors the light spot area of ​​the protruding road sign under test in real time. When a pixel detects a brightness change exceeding the threshold M, it outputs event data η = (x, y, t, p) to the optical resolution display component and updates the reference signal of that pixel. The threshold M is equal to the basic amount of voltage change detected by the pixel channel, M = k is the gain coefficient of the transient detection module;

[0100] Step 4.9. The optical resolution display component counts the data stream feedback from each pixel in the spot area every g seconds. The frame rate f of the calibration verification module is an integer multiple of the time interval g. The average voltage of each pixel in the spot area at the z-th statistical time is... for:

[0101]

[0102] In the formula, For the light spot area Each pixel channel; This represents the total number of pixel channels in the light spot area. For the first The pixel channel The feedback data; q is the first data point within g seconds. The total number of feedback data per pixel channel; For the first Each pixel channel detects the fundamental amount of voltage change;

[0103] The average brightness value L of the light spot area at the z-th statistical time point z，I for:

[0104]

[0105] Step 4.10. The calibration and verification module periodically measures the average brightness at a low frame rate f. If the two measurements are inconsistent, the value of the calibration and verification module is used as the standard for correction to achieve self-calibration.

[0106] In step 5, the specific operation of the optical resolution display component in outputting the retroreflection coefficient measurement value in real time based on the retroreflection coefficient calculation formula in the "Retroreflection Standard Calibration Specification" is as follows:

[0107] The average brightness value L of the area of ​​the protruding road sign light spot to be tested at the z-th statistical time obtained in step 4 is used. z，I , Effective light-receiving area S of the surface to be tested on the raised pavement marker, Vertical illuminance at the reference center of the light spot Substituting into the formula for the retroreflection coefficient, we obtain the retroreflection coefficient R at the z-th statistical time. z，I .

[0108] The beneficial effects of this invention are as follows:

[0109] This invention employs a transient detection module as the brightness detection unit, with each pixel channel working independently and responding at the microsecond level. It asynchronously outputs brightness change data in an event-driven manner, breaking through the bottleneck of traditional frame-type image sensors that are limited by a fixed frame rate and can only perform single-point, static, frame-by-frame measurements. It can continuously, in real time, and dynamically capture the retroreflection brightness changes of road reflective facilities, meeting the needs of road network status surveys and real-time monitoring.

[0110] In this invention, each pixel only performs threshold determination and output for the amount of brightness change, which effectively expands the dynamic response range of the system and takes into account both real-time measurement and high dynamic range measurement of brightness in the measurement of retroreflection parameters of road reflective facilities. It solves the problem that traditional measuring devices are prone to saturation distortion in strong retroreflection scenarios when vehicle lights illuminate reflective facilities at night.

[0111] The binocular vision imaging detector of this invention includes a calibration and verification module that periodically acquires an absolute brightness reference at a low frame rate, and performs real-time comparison and correction of the event accumulation results of the transient detection module. This self-calibration mechanism effectively suppresses temperature drift, pixel response non-uniformity, and long-term accumulated errors, ensuring that the system can maintain high accuracy and high stability for long-term continuous measurement even in complex field environments.

[0112] This invention flexibly adjusts the spatial orientation of the light source module and the photometric data acquisition module through a pose adjuster, and, in conjunction with the differentiated calculation formula built into the optical analysis display component, is applicable to the evaluation of the retroreflective performance of three main types of road traffic reflective safety facilities: road retroreflective signs, retroreflective markings, and raised pavement markers, significantly improving the versatility and economy of the equipment. Attached Figure Description

[0113] Figure 1 This is a schematic diagram of the structure of the real-time retroreflection coefficient monitoring device of Embodiment 1 of the present invention.

[0114] Figure 2 This is a block diagram of the electrical principle of the transient detection module.

[0115] Figure 3 This is a flowchart of the event triggering and output process for the transient detection module.

[0116] Figure 4 This is the optical path diagram for measuring the retroreflection brightness coefficient of the retroreflection caliper in Embodiment 2 of the present invention.

[0117] Figure 5 This is the optical path diagram for measuring the luminous intensity coefficient of the raised pavement in Embodiment 3 of the present invention.

[0118] The components include: 1. Road retroreflective sign; 2. Road surface; 3. Light source module; 4. Base; 5. Posture adjuster; 5. Base 501; 502. Column; 503. Mounting plate; 504. Multi-joint connecting arm; 505. Mounting head; 6. Calibration and verification module; 7. Early warning module; 8. Optical resolution display component; 9. Transient detection module; 10. Illuminance detector; 11. Retroreflective marking; 12. Raised pavement marker. Detailed Implementation

[0119] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments, but the present invention is not limited to the following embodiments.

[0120] Example 1

[0121] In this embodiment, road retroreflective sign 1 is used as the reflective facility to be tested.

[0122] exist Figure 1 In this invention, a real-time retroreflection coefficient monitoring device is provided. A pose adjuster 5 is installed on a base 4, which is a tripod. A light source module 3 and a retroreflection light receiving optical device are respectively installed on the pose adjuster 5. The pose adjuster 5 is used to adjust the spatial attitude of the light source module 3 and the retroreflection light receiving optical device so that the light spot emitted by the light source module 3 falls on the road retroreflection sign 1 to be measured. The retroreflected light formed on the road retroreflection sign 1 to be measured enters the retroreflection light receiving optical device.

[0123] The pose adjuster 5 in this embodiment includes a base 501, a column 502, a mounting plate 503, a multi-joint connecting arm 504, and a mounting head 505. The column 502 is mounted on the base 501, and the height-adjustable mounting plate 503 is provided on the column 502. Two multi-joint connecting arms 504 are provided on the mounting plate 503. The multi-joint connecting arms 504 are commercially available products, and the mounting head 505 is installed at the end of each multi-joint connecting arm 504. The mounting head 505 is connected to the light source module 3 and the retroreflective light receiving optical device via threaded fasteners.

[0124] In this embodiment, the retroreflective light receiving optics consists of an optical resolution display component 8 connected to the output of the photometric data acquisition module. The photometric data acquisition module comprises a binocular vision imaging detector and an illuminance detector 10 connected in parallel. The binocular vision imaging detector is used to acquire the microsecond-level high-speed brightness of the light emitted from the light source illuminating the surface of the reflective facility to be measured. The illuminance detector 10 is used to acquire the vertical illuminance value of the light source module 3 at the surface of the reflective facility to be measured. The optical resolution display component 8 processes the data acquired by the photometric data acquisition module using the built-in retroreflection coefficient calculation formula of the road retroreflection sign 1 to obtain and display the retroreflection coefficient measurement result.

[0125] The binocular vision imaging detector in this embodiment includes a transient detection module 9 and a calibration and verification module 6. The transient detection module 9 is used to detect changes in brightness in the area to be measured at the microsecond level, and the calibration and verification module 6 is used to provide reference brightness data for the transient detection module 9 and to perform verification.

[0126] exist Figure 2 , 3 In this embodiment, the transient detection module 9 includes an imaging optical unit, a pixel array unit, a brightness change detection unit, a threshold determination unit, a polarity determination unit, a timestamp generation unit, an address encoding unit, and a data output unit. The imaging optical unit is used to image the scene under test onto the pixel array unit. The pixel array unit contains multiple independent pixel channels, each of which converts the received light signal into a voltage signal and outputs it. The brightness change detection unit is used to compare the current voltage signal of each pixel channel with the voltage signal of the previous moment and output the voltage change. The threshold determination unit is used to compare the voltage change of each pixel channel with a preset threshold. For comparison, k is the gain coefficient of the transient detection module 9, used to determine whether the trigger condition has been met. When the voltage change is greater than or equal to the positive preset threshold... Or the voltage change is ≤ the negative preset threshold The event is determined to be a valid event; the polarity determination unit, based on the valid event, determines the polarity p of the brightness change, and the voltage change is greater than or equal to a positive preset threshold. Increased brightness indicates positive polarity, and voltage change ≤ negative preset threshold. The brightness decreases to negative polarity; the timestamp generation unit is used to record the occurrence time t for each valid event; the address encoding unit is used to assign pixel output position coordinates (x, y) for each valid event; and the data output unit is used to output the event data η = (x, y, t, p) representing the brightness change process of each pixel channel to the optical resolution display component 8.

[0127] In this embodiment, the output terminal of the optical resolution display component 8 is also connected to a warning module 7, which is used to generate an alarm when the measurement result exceeds the safety threshold.

[0128] The retroreflection coefficient monitoring method of the retroreflection coefficient real-time monitoring device of this embodiment is characterized by including the following steps:

[0129] Step 1. According to the national metrological technical specification "Calibration Specification for Retroreflective Standards", the retroreflection coefficient R is used. A As an evaluation indicator

[0130]

[0131] In the formula, The brightness reflected back to the observer's eye by road retroreflective sign 1. The vertical illuminance of light source module 3 at the reference center of the surface to be measured on road retroreflective sign 1;

[0132] Step 2. Analyze and evaluate the basic measurement parameters for real-time monitoring of retroreflection coefficient based on the luminance method: the luminance of the road retroreflection sign 1 reflected back to the observer's eye. Vertical illuminance of light source module 3 at the reference center of the surface to be measured on road retroreflective sign 1 ;

[0133] Step 3. By adjusting the spatial orientation of the light source module 3 and the photometric data acquisition module, ensure that the incident angle, observation angle, and viewing angle meet the requirements of the "Calibration Specification for Retroreflective Standards". The incident angle is the angle between the optical axis of the light source module 3 and the normal to the center of the area to be measured for the road retroreflective sign 1. The observation angle is the angle between the center normal of the transient detection module 9 and the optical axis of the light source module 3. ;

[0134] Step 4. Obtain the brightness data and effective light-receiving area parameters of the road retroreflection sign 1 reflected back to the observer's eye through the binocular vision imaging detector in the photometric data acquisition module. Simultaneously, obtain the vertical illuminance value of the light source module at the road retroreflection sign 1 through the illuminance detector in the photometric data acquisition module. The specific operation is as follows:

[0135] Step 4.1. Start the preheating of the light source module 3. After the preheating is completed, the illuminance detector 10 measures the illuminance value perpendicular to the optical axis at a distance l0 from the light-emitting surface of the light source module 3. The diameter of the light spot at 10 locations was measured using a ruler. ;

[0136] Step 4.2. Illuminate the surface of the road retroreflective sign 1 with the light emitted from the light source module 3 to form the light spot area of ​​the retroreflective sign to be tested;

[0137] Step 4.3. Set the brightness change criterion parameters for each pixel in the transient detection module 9. Set the aperture, exposure time, and frame rate of the calibration and verification module 6;

[0138] Step 4.4. Adjust the attitude of the binocular vision imaging detector so that the light spot is clearly imaged at the center of the field of view of the transient detection module 9 and the calibration and verification module 6, and record the distance l between the light spot and the light-emitting surface of the light source module at this time. A ;

[0139] Step 4.5. Extract the light spot region within the field of view of the calibration and verification module 6 using an image segmentation algorithm. Calculate the brightness value of each pixel in the light spot region based on the grayscale value of each pixel and the response curve function obtained from laboratory calibration. Take the average value as the initial brightness value L. 0，A ;

[0140] Step 4.6. Use an image segmentation algorithm to extract the light spot region within the field of view of the transient detection module 9. Based on the voltage values ​​of each pixel in the light spot region, take the average value as the initial voltage value V. 0，A Using the initial brightness value L 0，A For the initial voltage value V 0，A Perform the assignment and calibration;

[0141] Step 4.7. Based on the imaging size of the light spot on the transient detection module 9, count the number of pixels m along the minor axis. A The minor axis length D(l) of the light spot within the field of view of the transient detection module 9 is obtained according to the following formula. A ),

[0142]

[0143] In the formula, e is the equivalent of 9 pixels for the transient detection module;

[0144] The vertical illuminance at the reference center of the light spot for:

[0145]

[0146] Step 4.8. The transient detection module 9 independently monitors the retroreflection marker spot area in real time for each pixel. When a pixel detects a brightness change exceeding the threshold M, it outputs event data η = (x, y, t, p) to the optical resolution display component 8 and updates the reference signal of that pixel. The threshold M is equal to the basic amount of voltage change detected by the pixel channel, M = k is the gain coefficient of the transient detection module 9;

[0147] Step 4.9. The optical resolution display component 8 counts the data stream feedback from each pixel in the spot area every g seconds. The frame rate f of the calibration and verification module 6 is an integer multiple of the time interval g. The average voltage V of each pixel in the spot area at the z-th statistical moment is... z，A for:

[0148]

[0149] In the formula, For the light spot area Each pixel channel; This represents the total number of pixel channels in the light spot area. For the first The pixel channel The feedback data; q is the first data point within g seconds. The total number of feedback data per pixel channel; For the first Each pixel channel detects the fundamental amount of voltage change;

[0150] The average brightness value L of the light spot area at the z-th statistical time point z，A for:

[0151]

[0152] Step 4.10. The calibration and verification module 6 periodically measures the average brightness at a lower frame rate f. If the two measurements are inconsistent, the value of the calibration and verification module 6 is used as the standard for correction to achieve self-calibration.

[0153] Step 5. The optical resolution display component 8 displays the average brightness value L of the retroreflection marker spot area to be measured at the z-th statistical time, obtained in Step 4. z，A Vertical illuminance at the reference center of the light spot Substituting into the formula in step 1, we obtain the retroreflection coefficient R at the z-th statistical time. z，A retroreflection coefficient R z，A The warning module 7 issued an alarm when the safety threshold was exceeded.

[0154] Example 2

[0155] like Figure 4 In this embodiment, retroreflective marker 11 is used as the reflective device to be tested.

[0156] This embodiment of a retroreflection coefficient real-time monitoring device includes a pose adjuster 5 mounted on a base 4, which is a moving vehicle. The pose adjuster 5 is equipped with a light source module 3 and a retroreflection light receiving optics. The pose adjuster 5 is used to adjust the spatial attitude of the light source module 3 and the retroreflection light receiving optics so that the light spot emitted by the light source module 3 falls on the surface to be measured by the retroreflection mark 11, and the retroreflected light formed on the surface to be measured by the retroreflection mark 11 enters the retroreflection light receiving optics.

[0157] The pose adjuster 5 and the light source module 3 are the same as in Example 1.

[0158] The retroreflection light receiving optical device is connected to the output end of the photometric data acquisition module, and an optical resolution display component 8 is also connected to the output end of the optical resolution display component 8. The warning prompt module 7 and the photometric data acquisition module are the same as in Embodiment 1. The optical resolution display component 7 has a built-in formula for calculating the retroreflection coefficient of the retroreflection mark, which is used to process the data acquired by the photometric data acquisition module, obtain the retroreflection coefficient measurement result, and display it.

[0159] The retroreflection coefficient monitoring method of the real-time retroreflection coefficient monitoring device in this embodiment includes the following steps:

[0160] Step 1. According to the national metrological technical specification "Calibration Specification for Retroreflective Standard Instruments", the retroreflective brightness coefficient R is used. L As an evaluation indicator

[0161]

[0162] In the formula, The brightness of the retroreflective marker reflected back to the observer's eye. From the perspective of The vertical illuminance of light source module 3 at the reference center of the retroreflective caliper surface to be measured;

[0163] Step 2. Analyze and evaluate the basic measurement parameters for real-time monitoring of retroreflection coefficient based on the luminance method: the luminance L reflected back to the observer's eye by the retroreflection mark, and the vertical illuminance of the light source module 3 at the reference center of the surface to be measured on the retroreflection mark. Perspective ;

[0164] Step 3. Adjust the spatial orientation of the light source module 3 and the photometric data acquisition module to ensure that the incident angle, observation angle, and viewing angle meet the requirements of the "Calibration Specification for Retroreflective Standards". The incident angle is the angle between the optical axis of the light source module 3 and the normal to the center of the area to be measured on the retroreflective marker 11. The observation angle is the angle between the center normal of the transient detection module 9 and the optical axis of the light source module 3. perspective ;

[0165] Step 4. Obtain the brightness data and effective light-receiving area parameters reflected back to the observer's eye from the retroreflection mark 11 using the binocular vision imaging detector in the photometric data acquisition module. Simultaneously, obtain the vertical illuminance value of the light source module 3 at the retroreflection mark 11 using the illuminance detector 10 in the photometric data acquisition module. The specific operation is as follows:

[0166] Step 4.1. Start the preheating of the light source module 3. After preheating, the illuminance detector 10 measures the illuminance value perpendicular to the optical axis at a known distance l0. Measure the diameter of the light spot using a ruler. ;

[0167] Step 4.2. Illuminate the surface of the retroreflective marker with the light emitted from the light source module 3 to form the retroreflective marker spot area to be tested;

[0168] Step 4.3. Set the brightness change criterion parameters for each pixel in the transient detection module 9. Set the aperture, exposure time, and frame rate of the calibration and verification module 6;

[0169] Step 4.4. Adjust the attitude of the binocular vision imaging detector so that the light spot is clearly imaged at the center of the field of view of the transient detection module 9 and the calibration and verification module 6, and record the distance l between the light spot and the light-emitting surface of the light source module at this time. L ;

[0170] Step 4.5. Extract the light spot region within the field of view of the calibration and verification module 6 using an image segmentation algorithm. Calculate the brightness value of each pixel in the light spot region based on the grayscale value of each pixel and the response curve function obtained from laboratory calibration. Take the average value as the initial brightness value. 0，L ;

[0171] Step 4.6. Use an image segmentation algorithm to extract the light spot region within the field of view of the transient detection module 9. Based on the voltage values ​​of each pixel in the light spot region, take the average value as the initial voltage value V. 0，L Using the initial brightness value l 0，L For the initial voltage value V 0，L Perform the assignment and calibration;

[0172] Step 4.7. Based on the imaging size of the light spot on the transient detection module 9, count the number of pixels m along the minor axis. L The minor axis length D(l) of the light spot within the field of view of the transient detection module 9 is obtained according to the following formula. L ),

[0173]

[0174] The vertical illuminance at the reference center of the light spot for:

[0175]

[0176] Step 4.8. The transient detection module 9 independently monitors the retroreflective marker spot area in real time for each pixel. When a pixel detects a brightness change exceeding the threshold M, it outputs event data η = (x, y, t, p) to the optical resolution display component 8 and updates the reference signal of that pixel. The threshold M is equal to the basic amount of voltage change detected by the pixel channel, M = k is the gain coefficient of the transient detection module 9;

[0177] Step 4.9. The optical resolution display component 8 counts the data stream feedback from each pixel in the spot area every g seconds. The frame rate f of the calibration and verification module 6 is an integer multiple of the time interval g. The average voltage V of each pixel in the spot area at the z-th statistical moment is... z，A for:

[0178]

[0179] In the formula, For the light spot area Each pixel channel; This represents the total number of pixel channels in the light spot area. For the first The pixel channel The feedback data; q is the first data point within g seconds. The total number of feedback data per pixel channel; For the first Each pixel channel detects the fundamental amount of voltage change;

[0180] The average brightness value L of the light spot area at the z-th statistical time point z，L for:

[0181]

[0182] Step 4.10. The calibration and verification module 6 periodically measures the average brightness at a lower frame rate f. If the two measurements are inconsistent, the value of the calibration and verification module 6 is used as the standard for correction to achieve self-calibration.

[0183] Step 5. The optical analysis and display component 8 displays the average brightness value L of the retroreflective mark spot area to be measured at the z-th statistical time, obtained in Step 4. z，L Vertical illuminance E at the reference center of the light spot ⊥L Substituting into the formula in step 1, we obtain the retroreflection coefficient R at the z-th statistical time. z，L retroreflection coefficient R z，L The warning module 7 issued an alarm when the safety threshold was exceeded.

[0184] Example 3

[0185] like Figure 5 In this embodiment, the raised pavement marker 12 is used as the reflective device to be tested.

[0186] This embodiment of a retroreflection coefficient real-time monitoring device includes a pose adjuster 5 mounted on a base 4, which is a moving vehicle. The pose adjuster 5 is equipped with a light source module 3 and a retroreflection light receiving optics. The pose adjuster 5 is used to adjust the spatial attitude of the light source module 3 and the retroreflection light receiving optics so that the light spot emitted by the light source module 3 falls on the surface to be measured of the protruding road sign 12, and the retroreflected light formed on the surface to be measured of the protruding road sign 12 enters the retroreflection light receiving optics.

[0187] The pose adjuster 5 and the light source module 3 are the same as in Example 1.

[0188] The retroreflection light receiving optical device is connected to the output end of the photometric data acquisition module, and an optical resolution display component 8 is also connected to the output end of the optical resolution display component 8. The warning prompt module 7 and the photometric data acquisition module are the same as in Embodiment 1. The optical resolution display component 7 has a built-in formula for calculating the retroreflection coefficient of the protruding road sign, which is used to process the data collected by the photometric data acquisition module, obtain the retroreflection coefficient measurement result, and display it.

[0189] The retroreflection coefficient monitoring method of the real-time retroreflection coefficient monitoring device in this embodiment includes the following steps:

[0190] Step 1. According to the national metrological technical specification "Calibration Specification for Retroreflective Standards", the luminous intensity coefficient R is used. I As an evaluation indicator

[0191]

[0192] In the formula, S is the effective light-receiving area of ​​the surface to be tested on the raised pavement marker 12;

[0193] Step 2. Analyze and evaluate the basic measurement parameters for real-time monitoring of retroreflection coefficient based on the luminance method: the luminance reflected back to the observer's eye from the protruding road sign. Vertical illuminance of light source module 3 at the reference center of the surface to be measured on the raised pavement marker Perspective ;

[0194] Step 3. Adjust the spatial orientation of the light source module 3 and the photometric data acquisition module to ensure that the incident angle, observation angle, and viewing angle meet the requirements of the "Calibration Specification for Retroreflective Standards". The incident angle is the angle between the optical axis of the light source module 3 and the normal to the center of the area to be measured on the raised landmark. The observation angle is the angle between the center normal of the transient detection module 9 and the optical axis of the light source module 3. perspective ;

[0195] Step 4. Obtain the brightness data and effective light-receiving area parameters reflected back to the observer's eye from the raised road sign 12 using the binocular vision imaging detector in the photometric data acquisition module; simultaneously, obtain the vertical illuminance value of the light source module 3 at the raised road sign 12 using the illuminance detector 10 in the photometric data acquisition module. The specific operation is as follows:

[0196] Step 4.1. Start the preheating of the light source module 3. After the preheating is completed, the illuminance detector 10 measures the illuminance value perpendicular to the optical axis at a distance l0 from the light-emitting surface of the light source module 3. Measure the diameter of the light spot using a ruler. ;

[0197] Step 4.2. Illuminate the surface of the raised pavement with the light emitted from the light source module 3 to form a light spot area of ​​the raised pavement to be tested;

[0198] Step 4.3. Set the brightness change criterion parameters for each pixel in the transient detection module 9. Set the aperture, exposure time, and frame rate of the calibration and verification module 6;

[0199] Step 4.4. Adjust the attitude of the binocular vision imaging detector so that the light spot is clearly imaged at the center of the field of view of the transient detection module 9 and the calibration and verification module 6, and record the distance l at this time. I ;

[0200] Step 4.5. Extract the light spot region within the field of view of the calibration and verification module 6 using an image segmentation algorithm. Calculate the brightness value of each pixel in the light spot region based on the grayscale value of each pixel and the response curve function obtained from laboratory calibration. Take the average value as the initial brightness value L. 0，I ;

[0201] Step 4.6. Use an image segmentation algorithm to extract the light spot region within the field of view of the transient detection module 9. Based on the voltage values ​​of each pixel in the light spot region, take the average value as the initial voltage value V. 0，I Using the initial brightness value L 0，I For the initial voltage value V 0，I Perform the assignment and calibration;

[0202] Step 4.7. Based on the imaging size of the light spot on the transient detection module 9, count the number of pixels m along the minor axis. I and the number of pixels n along the major axis I The minor axis length D(l) of the light spot within the field of view of the transient detection module 9 is obtained according to the following formula. I ),

[0203]

[0204] The vertical illuminance E at the reference center of the light spot ⊥I for:

[0205]

[0206] The effective light-receiving area S of the surface to be tested on the raised pavement marker is:

[0207]

[0208] Step 4.8. The transient detection module 9 independently monitors the retroreflection marker spot area in real time for each pixel. When a pixel detects a brightness change exceeding the threshold M, it outputs event data η = (x, y, t, p) to the optical resolution display component 8 and updates the reference signal of that pixel. The threshold M is equal to the basic amount of voltage change detected by the pixel channel, M = k is the gain coefficient of the transient detection module 9;

[0209] Step 4.9. The optical resolution display component 8 counts the data stream feedback from each pixel in the spot area every g seconds. The frame rate f of the calibration and verification module 6 is an integer multiple of the time interval g. The average voltage V of each pixel in the spot area at the z-th statistical moment is... z，A for:

[0210]

[0211] In the formula, For the light spot area Each pixel channel; This represents the total number of pixel channels in the light spot area. For the first The pixel channel The feedback data; q is the first data point within g seconds. The total number of feedback data per pixel channel; For the first Each pixel channel detects the fundamental amount of voltage change;

[0212] The average brightness value L of the light spot area at the z-th statistical time point z，I for:

[0213]

[0214] Step 4.10. The calibration and verification module 6 periodically measures the average brightness at a lower frame rate f. If the two measurements are inconsistent, the value of the calibration and verification module 6 is used as the standard for correction to achieve self-calibration.

[0215] Step 5. The optical resolution display component 8 displays the average brightness value L of the area of ​​the protruding road sign light spot to be measured at the z-th statistical time, obtained in Step 4.z，I Vertical illuminance at the reference center of the light spot Substituting into the formula in step 1, we obtain the retroreflection coefficient R at the z-th statistical time. z，I retroreflection coefficient R z，I The warning module 7 issued an alarm when the safety threshold was exceeded.

Claims

1. A real-time monitoring device for retroreflection coefficient, characterized in that: A pose adjuster is provided on the base, and a light source module and a retroreflective light receiving optical device are respectively installed on the pose adjuster. The pose adjuster is used to adjust the spatial attitude of the light source module and the retroreflective light receiving optical device so that the light spot emitted by the light source module falls on the test surface of the reflective facility, and the retroreflective light formed on the test surface of the reflective facility enters the retroreflective light receiving optical device. The retroreflective light receiving optical device is an optical resolution display component connected to the output end of the photometric data acquisition module. The photometric data acquisition module consists of a binocular vision imaging detector and an illuminance detector connected in parallel. The binocular vision imaging detector is used to acquire the microsecond-level high-speed brightness of the light emitted from the light source illuminating the surface to be measured of the reflective facility. The illuminance detector is used to acquire the vertical illuminance value of the light source module at the surface to be measured of the reflective facility. The optical analysis and display component processes the data acquired by the photometric data acquisition module using the built-in retroreflection coefficient calculation formula to obtain and display the retroreflection coefficient measurement result.

2. The real-time retroreflection coefficient monitoring device according to claim 1, characterized in that: The base can be a fixed platform or a mobile platform.

3. The real-time retroreflection coefficient monitoring device according to claim 1, characterized in that: The binocular vision imaging detector includes a transient detection module and a calibration and verification module. The transient detection module is used to detect changes in brightness in the area under test at the microsecond level. The calibration and verification module is used to provide reference brightness data for the transient detection module and to perform verification.

4. The real-time retroreflection coefficient monitoring device according to claim 3, characterized in that: The transient detection module includes an imaging optical unit, a pixel array unit, a brightness change detection unit, a threshold determination unit, a polarity determination unit, a timestamp generation unit, an address encoding unit, and a data output unit. The imaging optical unit is used to image the scene under test onto the pixel array unit; The pixel array unit contains multiple independent pixel channels, each pixel channel being used to convert the received optical signal into a voltage signal and output it. The brightness change detection unit is used to compare the current voltage signal of each pixel channel with the voltage signal at the previous moment and output the voltage change amount. The threshold determination unit is used to compare the voltage change of each pixel channel with a preset threshold to determine whether the triggering condition is met. When the voltage change is ≥ the positive preset threshold or the voltage change is ≤ the negative preset threshold, it is determined to be a valid event. The polarity determination unit determines the polarity p of the brightness change based on valid events. If the voltage change is greater than or equal to a positive preset threshold, the brightness increases and the polarity is positive. If the voltage change is less than or equal to a negative preset threshold, the brightness decreases and the polarity is negative. The timestamp generation unit is used to record the occurrence time t for each valid event; The address encoding unit is used to output the pixel position coordinates (x, y) for each valid event; The data output unit is used to output the event data η = (x, y, t, p) representing the brightness change process of each pixel channel to the optical resolution display component.

5. The real-time retroreflection coefficient monitoring device according to claim 1, characterized in that: The posture adjuster has a base with a column, a height-adjustable mounting plate on the column, and two multi-joint connecting arms on the mounting plate, with mounting heads at the ends of the multi-joint connecting arms.

6. The real-time retroreflection coefficient monitoring device according to any one of claims 1-5, characterized in that: The output terminal of the optical resolution display component is also connected to an early warning module, which is used to generate an alarm when the measurement result exceeds the safety threshold.

7. The retroreflection coefficient monitoring method of the real-time retroreflection coefficient monitoring device according to any one of claims 6, characterized in that, Includes the following steps: Step 1. Determine the evaluation index of retroreflection coefficient for different types of reflective facilities according to the national metrological technical specification "Calibration Specification for Retroreflective Standards"; Step 2. Analyze and evaluate the indicators to determine the basic measurement parameters for real-time monitoring of retroreflection coefficient based on the luminance method; Step 3. Adjust the spatial orientation of the light source module and the photometric data acquisition module to ensure that the incident angle, observation angle, and viewing angle meet the requirements of the "Calibration Specification for Retroreflective Standard". Step 4. Obtain the brightness data and effective light-receiving area parameters reflected back to the observer's eyes by the binocular vision imaging detector in the photometric data acquisition module; obtain the vertical illuminance values ​​of the light source module at different types of road traffic reflective safety facilities by the illuminance detector in the photometric data acquisition module. Step 5. The optical analysis display component outputs the retroreflection coefficient measurement value in real time based on the retroreflection coefficient calculation formula in the "Retroreflection Standard Calibration Specification". If the measurement value exceeds the safety threshold, the warning module will issue an alarm.

8. The retroreflection coefficient monitoring method of the real-time retroreflection coefficient monitoring device according to claim 7, characterized in that, The reflective device in step 1 is a road retroreflective sign, using a retroreflection coefficient R. A As an evaluation indicator In the formula, The brightness of the road retroreflective sign reflected back to the observer's eye. The vertical illuminance of the light source module at the reference center of the road retroreflective sign surface to be measured; In step 2, the basic measurement parameter is: the brightness of the road retroreflective sign reflected back to the observer's eye. Vertical illuminance of the light source module at the reference center of the road retroreflective sign surface to be measured. ; In step 3, the incident angle is the angle between the optical axis of the light source module and the normal to the center of the area to be measured of the road retroreflection sign. The observation angle is the angle between the center normal of the transient detection module and the optical axis of the light source module. ; The specific operation of step 4 is as follows: Step 4.

1. Start the preheating of the light source module. After preheating, the illuminance detector measures the illuminance value perpendicular to the optical axis at a distance l0 from the light-emitting surface of the light source module. The diameter of the light spot at 10 locations was measured using a ruler. ; Step 4.

2. Illuminate the surface of the road retroreflective sign with the light emitted from the light source module to form the light spot area of ​​the retroreflective sign to be tested; Step 4.

3. Set the brightness change criterion parameters for each pixel in the transient detection module. Set the aperture, exposure time, and frame rate of the calibration and verification module; Step 4.

4. Adjust the attitude of the binocular vision imaging detector so that the light spot is clearly imaged at the center of the field of view of the transient detection module and the calibration verification module, and record the distance l between the light spot and the light-emitting surface of the light source module at this time. A ; Step 4.

5. Extract the spot area within the field of view of the calibration and verification module using an image segmentation algorithm. Calculate the brightness value of each pixel in the spot area based on the grayscale value of each pixel and the response curve function obtained from laboratory calibration. Take the average value as the initial brightness value L. 0，A ; Step 4.

6. Extract the light spot region within the field of view of the transient detection module using an image segmentation algorithm. Take the average value of the voltage values ​​of each pixel in the light spot region as the initial voltage value V. 0，A Using the initial brightness value L 0，A For the initial voltage value V 0，A Perform the assignment and calibration; Step 4.

7. Based on the imaging size of the light spot on the transient detection module, count the number of pixels m along the minor axis. A The minor axis length D(l) of the light spot within the field of view of the transient detection module is obtained according to the following formula. A ), In the formula, e is the pixel equivalent of the transient detection module; The vertical illuminance at the reference center of the light spot for: Step 4.

8. Each pixel in the transient detection module independently monitors the retroreflection marker spot area in real time. When a pixel detects a brightness change exceeding the threshold M, it outputs event data η = (x, y, t, p) to the optical resolution display component and updates the reference signal of that pixel. The threshold M is equal to the basic amount of voltage change detected by the pixel channel, M = k is the gain coefficient of the transient detection module; Step 4.

9. The optical resolution display component counts the data stream feedback from each pixel in the spot area every g seconds. The frame rate f of the calibration verification module is an integer multiple of the time interval g. The average voltage V of each pixel in the spot area at the z-th statistical time is... z，A for: In the formula, For the light spot area Each pixel channel; This represents the total number of pixel channels in the light spot area. For the first The pixel channel The feedback data; q is the first data point within g seconds. The total number of feedback data per pixel channel; For the first Each pixel channel detects the basic voltage change; The average brightness value L of the light spot area at the z-th statistical time point z，A for: Step 4.

10. The calibration and verification module periodically measures the average brightness at a low frame rate f. If the two measurements are inconsistent, the value of the calibration and verification module is used as the standard for correction to achieve self-calibration. In step 5, the specific operation of the optical resolution display component in outputting the retroreflection coefficient measurement value in real time based on the retroreflection coefficient calculation formula in the "Retroreflection Standard Calibration Specification" is as follows: The average brightness value L of the retroreflection marker spot area to be measured at the z-th statistical time obtained in step 4 is used. z，A Vertical illuminance at the reference center of the light spot Substituting into the formula for the retroreflection coefficient, we obtain the retroreflection coefficient R at the z-th statistical time. z，A .

9. The retroreflection coefficient monitoring method of the real-time retroreflection coefficient monitoring device according to claim 7, characterized in that, The reflective device in step 1 is a retroreflective marker, using a retroreflective brightness coefficient R. L As an evaluation indicator In the formula, The brightness of the retroreflective marker reflected back to the observer's eye. From the perspective of The vertical illuminance of the light source module at the reference center of the retroreflective surface to be measured; In step 2, the basic measurement parameter is: the brightness of the retroreflective marker reflected back to the observer's eye. The vertical illuminance of the light source module at the reference center of the retroreflective surface to be measured. Perspective ; In step 3, the incident angle is the angle between the optical axis of the light source module and the normal to the center of the area to be measured by the retroreflection marker. The observation angle is the angle between the center normal of the transient detection module and the optical axis of the light source module. perspective ; The specific operation of step 4 is as follows: Step 4.

1. Start the preheating of the light source module. After preheating, the illuminance detector measures the illuminance value perpendicular to the optical axis at a distance l0 from the light-emitting surface of the light source module. The diameter of the light spot at 10 locations was measured using a ruler. ; Step 4.

2. Illuminate the surface of the retroreflective marking with the light emitted from the light source module to form a light spot area of ​​the retroreflective marking to be tested; Step 4.

3. Set the brightness change criterion parameters for each pixel in the transient detection module. Set the aperture, exposure time, and frame rate of the calibration and verification module; Step 4.

4. Adjust the attitude of the binocular vision imaging detector so that the light spot is clearly imaged at the center of the field of view of the transient detection module and the calibration verification module, and record the distance l between the light spot and the light-emitting surface of the light source module at this time. L ; Step 4.

5. Extract the spot area within the field of view of the calibration and verification module using an image segmentation algorithm. Calculate the brightness value of each pixel in the spot area based on the grayscale value of each pixel and the response curve function obtained from laboratory calibration. Take the average value as the initial brightness value L. 0，L ; Step 4.

6. Extract the light spot region within the field of view of the transient detection module using an image segmentation algorithm. Take the average value of the voltage values ​​of each pixel in the light spot region as the initial voltage value V. 0，L Using the initial brightness value L 0，L For the initial voltage value V 0，L Perform the assignment and calibration; Step 4.

7. Based on the imaging size of the light spot on the transient detection module, count the number of pixels m along the minor axis. L The minor axis length D(l) of the light spot within the field of view of the transient detection module is obtained according to the following formula. L ), In the formula, e is the pixel equivalent of the transient detection module; The vertical illuminance at the reference center of the light spot for: Step 4.

8. Each pixel in the transient detection module independently monitors the retroreflective marker spot area in real time. When a pixel detects a brightness change exceeding the threshold M, it outputs event data η = (x, y, t, p) to the optical resolution display component and updates the reference signal of that pixel. The threshold M is equal to the basic value of the voltage change detected by the pixel channel, M = k is the gain coefficient of the transient detection module; Step 4.

9. The optical resolution display component counts the data stream feedback from each pixel in the spot area every g seconds. The frame rate f of the calibration verification module is an integer multiple of the time interval g. The average voltage of each pixel in the spot area at the z-th statistical time is... for: In the formula, For the light spot area Each pixel channel; This represents the total number of pixel channels in the light spot area. For the first The pixel channel The feedback data; q is the first data point within g seconds. The total number of feedback data per pixel channel; For the first Each pixel channel detects the basic voltage change; The average brightness value L of the light spot area at the z-th statistical time point z，L for: Step 4.

10. The calibration and verification module periodically measures the average brightness at a low frame rate f. If the two measurements are inconsistent, the value of the calibration and verification module is used as the standard for correction to achieve self-calibration. In step 5, the specific operation of the optical resolution display component in outputting the retroreflection coefficient measurement value in real time based on the retroreflection coefficient calculation formula in the "Retroreflection Standard Calibration Specification" is as follows: The parameters obtained in step 4 are the average brightness value L of the retroreflective marking spot area to be measured at the z-th statistical time. z，L Vertical illuminance at the reference center of the light spot Substituting into the formula for the retroreflection coefficient, we obtain the retroreflection coefficient R at the z-th statistical time. z，L .

10. The retroreflection coefficient monitoring method of the real-time retroreflection coefficient monitoring device according to claim 7, characterized in that, The reflective device in step 1 is a raised pavement marker, using a luminous intensity coefficient R. I As an evaluation indicator In the formula, S is the effective light-receiving area of ​​the surface of the raised pavement marker to be tested. The brightness reflected back to the observer's eye from the protruding road sign. The vertical illuminance of the light source module at the reference center of the surface to be measured on the protruding road sign; In step 2, the basic measurement parameter is: the brightness of the reflection of the raised road sign back to the observer's eye. Vertical illuminance of the light source module at the reference center of the surface to be measured on the raised road sign Perspective α I ; In step 3, the incident angle is the angle between the optical axis of the light source module and the normal to the center of the area to be measured of the protruding landmark. The observation angle is the angle between the center normal of the transient detection module and the optical axis of the light source module. perspective ; The specific operation of step 4 is as follows: Step 4.

1. Start the preheating of the light source module. After preheating, the illuminance detector measures the illuminance value perpendicular to the optical axis at a distance l0 from the light-emitting surface of the light source module. The diameter of the light spot at 10 locations was measured using a ruler. ; Step 4.

2. Illuminate the surface of the raised pavement with the light emitted from the light source module to form a light spot area of ​​the raised pavement to be tested; Step 4.

3. Set the brightness change criterion parameters for each pixel in the transient detection module. Set the aperture, exposure time, and frame rate of the calibration and verification module; Step 4.

4. Adjust the attitude of the binocular vision imaging detector so that the light spot is clearly imaged at the center of the field of view of the transient detection module and the calibration verification module, and record the distance l between the light spot and the light-emitting surface of the light source module at this time. I ; Step 4.

5. Extract the spot area within the field of view of the calibration and verification module using an image segmentation algorithm. Calculate the brightness value of each pixel in the spot area based on the grayscale value of each pixel and the response curve function obtained from laboratory calibration. Take the average value as the initial brightness value L. 0，I ; Step 4.

6. Extract the light spot region within the field of view of the transient detection module using an image segmentation algorithm. Take the average value of the voltage values ​​of each pixel in the light spot region as the initial voltage value V. 0，I Using the initial brightness value L 0，I For the initial voltage value V 0，I Perform the assignment and calibration; Step 4.

7. Based on the imaging size of the light spot on the transient detection module, count the number of pixels m along the minor axis. I and the number of pixels n along the major axis I The minor axis length D(l) of the light spot within the field of view of the transient detection module is obtained according to the following formula. I ), In the formula, e is the pixel equivalent of the transient detection module; The vertical illuminance at the reference center of the light spot for: The effective light-receiving area S of the surface to be tested on the raised pavement marker is: Step 4.

8. Each pixel of the transient detection module independently monitors the light spot area of ​​the protruding road sign under test in real time. When a pixel detects a brightness change exceeding the threshold M, it outputs event data η = (x, y, t, p) to the optical resolution display component and updates the reference signal of that pixel. The threshold M is equal to the basic amount of voltage change detected by the pixel channel, M = k is the gain coefficient of the transient detection module; Step 4.

9. The optical resolution display component counts the data stream feedback from each pixel in the spot area every g seconds. The frame rate f of the calibration verification module is an integer multiple of the time interval g. The average voltage of each pixel in the spot area at the z-th statistical time is... for: In the formula, For the light spot area Each pixel channel; This represents the total number of pixel channels in the light spot area. For the first Pixel channel number The feedback data; q is the first data point within g seconds. Total number of pixel channel feedback data; For the first Each pixel channel detects the basic voltage change; The average brightness value L of the light spot area at the z-th statistical time point z，I for: Step 4.

10. The calibration and verification module periodically measures the average brightness at a low frame rate f. If the two measurements are inconsistent, the value of the calibration and verification module is used as the standard for correction to achieve self-calibration. In step 5, the specific operation of the optical resolution display component in outputting the retroreflection coefficient measurement value in real time based on the retroreflection coefficient calculation formula in the "Retroreflection Standard Calibration Specification" is as follows: The average brightness value L of the area of ​​the protruding road sign light spot to be tested at the z-th statistical time obtained in step 4 is used. z，I , Effective light-receiving area S of the surface to be tested on the raised pavement marker, Vertical illuminance at the reference center of the light spot Substituting into the formula for the retroreflection coefficient, we obtain the retroreflection coefficient R at the z-th statistical time. z，I .

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