Pavement flatness measurement module and detection device

Abstract

The utility model provides a road surface evenness measuring module and a detecting device, the road surface evenness measuring module is installed on a road roller and completes measurement in the working process of the road roller, and the road surface evenness measuring module comprises a laser, a laser light source, a laser light source, a signal processing module and a signal processing module, the laser light source projects linear laser rays to a road surface to be measured, and light spots are formed on the road surface to be measured; the image acquisition component and the laser device are mounted in a coplanar manner, and the image acquisition component acquires light spots projected on the road surface by the laser device to obtain a laser stripe two-dimensional image; the three-axis vibration sensor is used for monitoring the three-axis offset of the road surface flatness measurement module caused by the vibration of the steel wheel of the road roller and the pitch angle of the road roller; the anti-vibration support is mounted on the road roller and used for fixing the laser, the image acquisition component and the three-axis vibration sensor, and the anti-vibration support is provided with a damping structure. According to the utility model, real-time and accurate flatness measurement of a road section after rolling can be realized without vibration interference of the road roller.

Description

Technical Field

[0001] The utility model relates to the technical field of road quality measurement, and specifically, to a road surface flatness measurement module and a detection device. Background Technique

[0002] The road surface flatness is one of the key indicators for evaluating road quality, which reflects the amplitude and frequency of the height changes on the road surface. Generally, the flatness is characterized by measuring the elevation changes of the road longitudinal section. The quality of road flatness is closely related to the safety and comfort of passing vehicles. A road surface with poor flatness will increase vehicle fuel consumption, exacerbate mechanical wear, affect vehicle life, and seriously affect the passing experience of passengers. A road surface with better flatness has less resistance and impact on driving, high safety, smooth vehicle driving, and significantly increases the passing speed. In order to ensure traffic efficiency, driving safety, and passing experience, the accurate measurement of road surface flatness is very crucial.

[0003] During the production and paving process of the road surface, the roller needs to repeatedly compact the asphalt through the vibration of the steel wheel to achieve road surface flatness. Often, it is necessary to increase the number of rollers and the number of rolling times to ensure the relative flatness of the road surface. This method cannot accurately control the operation effect. Therefore, quality problems still occur during the road acceptance stage, resulting in rework, reducing the project efficiency, and causing a large amount of losses.

[0004] Currently, commonly used road surface flatness measurement devices such as three-meter straightedges, continuous flatness meters, bump integrators, and laser profilers cannot be used to detect during the road production process. In order to improve the quality of road construction, avoid rework problems, and improve production efficiency, a device that can measure the road surface flatness information in real time during the road production and construction process and provide guidance for construction has become an urgent need in the industry.

[0005] In the prior art, for example, Chinese Utility Model Patent CN116240777A discloses a road surface flatness evaluation device and method. A line laser and a 3D camera are both installed at the rear end of the roller through a camera bracket, and this solution realizes continuous evaluation of the entire road section. However, for the road surface flatness evaluation device adopted in this patent, it is very difficult to ensure the stability of the measurement module during the process of realizing real-time detection of the road surface flatness, and it cannot solve the measurement errors caused by the vibration of the roller itself during operation. In addition, it is also impossible to obtain the three-dimensional point cloud information of the complete road surface well by using the above device, which has a certain impact on the subsequent flatness evaluation. Content of the Utility Model

[0006] Aiming at the defects in the prior art, the purpose of the utility model is to provide a road surface flatness measurement module and a detection device, which can realize real-time detection of the road surface flatness during the road construction process and ensure high flatness of the road surface during the production stage.

[0007] In one aspect of the present utility model, a road surface flatness measurement module is provided. The road surface flatness measurement module is installed on a road roller and completes measurement during the operation of the road roller. It includes:

[0008] A laser, which projects a linear laser beam onto the road surface to be measured, forming a light spot on the road surface to be measured;

[0009] An image acquisition component, which is installed coplanarly with the laser. The image acquisition component acquires the light spot projected by the laser on the road surface to obtain a two-dimensional laser stripe image;

[0010] A three-axis vibration sensor, which monitors the three-axis offset brought to the road surface flatness measurement module by the vibration of the steel wheel of the road roller and the pitching angle of the road roller;

[0011] An anti-vibration bracket, which is installed on the road roller and is used to fix the laser, the image acquisition component and the three-axis vibration sensor. The anti-vibration bracket is provided with a shock-absorbing structure to ensure the stability of the laser, the image acquisition component and the three-axis vibration sensor.

[0012] Optionally, the road surface flatness measurement module is installed at the center position of the rear end of the road roller and above the steel wheel, and the anti-vibration bracket is installed at the center position of the rear end of the road roller.

[0013] Optionally, the image acquisition component is arranged above the laser and forms an angle with it.

[0014] Optionally, the laser is a line structured light laser. The linear light spot projected by the line structured light laser on the road surface is perpendicular to the rolling direction of the road roller, and the length of the linear light spot covers the rolling range, realizing the scanning of the road surface profile in the driving direction of the road roller.

[0015] Optionally, the image acquisition component is provided with an infrared band filter identical to the line structure laser, and the infrared band filter is placed inside the image acquisition component. Further, the image acquisition component uses an industrial camera, and the industrial camera includes an image sensor, a camera circuit board and a lens, and the lens uses a fish-eye lens. Preferably, the infrared band filter is arranged behind the lens of the industrial camera and in front of the image sensor, and the light will first pass through the lens and then reach the image sensor through the infrared band filter.

[0016] Optionally, the shock-absorbing structure is a shock absorber and shock-absorbing rubber. Among them, the shock absorbers are arranged in an array, and each shock absorber fixes the road roller and the road surface flatness measurement module through a connecting piece, and the shock-absorbing rubber is arranged between the shock absorber and the road roller and the road surface flatness measurement module.

[0017] Optionally, the three-axis vibration sensor includes an accelerometer and an inclinometer, and is installed on the road roller; the three-axis vibration sensor is a sensor for obtaining three-axis millimeter-level displacement, and the three-axis vibration sensor has an angular resolution of <0.01°.

[0018] In a second aspect of the present invention, there is provided a road surface flatness detection device, including: a road surface flatness measurement module installed on a road roller, and a differential positioning module disposed on the body of the road roller.

[0019] Optionally, the flatness detection device further includes a processing terminal. The output ends of the image acquisition component and the three-axis vibration sensor in the road surface flatness measurement module are both connected to the processing terminal, and the output end of the processing terminal is connected to a display module.

[0020] Compared with the prior art, the present invention has at least one of the following beneficial effects:

[0021] The road surface flatness measurement module provided by the present invention, in which a laser, an image acquisition component, a three-axis vibration sensor, and an anti-vibration bracket form a stable structured light road surface flatness measurement module, and the road surface flatness measurement module is installed on a road roller, realizing real-time and accurate flatness measurement of the rolled section without being disturbed by the vibration of the road roller.

[0022] The road surface flatness detection device provided by the present invention projects a laser line onto the ground, and the image acquisition component scans the road surface completely as the road roller moves forward, and can obtain a complete three-dimensional point cloud of the road surface, with high data density, coverage, integrity, authenticity, and accuracy.

[0023] The road surface flatness detection device provided by the present invention realizes real-time and accurate flatness measurement of the rolled section without being disturbed by the vibration of the road roller, and at the same time obtains a complete three-dimensional topography of the road surface and visualizes it, providing real-time reference for the road surface compaction status for construction personnel, and facilitating timely and accurate recompaction and correction.

[0024] The road surface flatness detection device provided by the present invention can further optimize the measurement distance to 1.5 m while ensuring the measurement accuracy, away from the high-temperature road surface, and can be well applied to the detection of flatness during the road surface compaction process, further ensuring the stability of the work. Description of the Drawings

[0025] By reading the detailed description of the non-limiting embodiments with reference to the following drawings, other features, purposes, and advantages of the present invention will become more obvious:

[0026] Figure 1 It is a schematic structural diagram of a road surface flatness measurement module according to an embodiment of the present invention;

[0027] Figure 2 Schematic diagram of the overall working layout of the road surface flatness measurement module in an embodiment of the present utility model;

[0028] Figure 3 Partial enlarged schematic diagram of the anti-vibration bracket in an embodiment of the present utility model;

[0029] Figure 4 Module structure diagram of the road surface flatness detection device in an embodiment of the present utility model.

[0030] In the figure:

[0031] Road surface flatness test module 1, differential positioning module 2, processing terminal 3;

[0032] Image acquisition component 101, laser 102, three-axis vibration sensor 103, anti-vibration bracket 104. Specific implementation manners

[0033] The present utility model will be described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present utility model, but do not limit the present utility model in any form. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present utility model, several modifications and improvements can still be made. These all belong to the protection scope of the present utility model.

[0034] Referring to Figure 1 As shown, in an embodiment of the present utility model, a road surface flatness measurement module 1 is provided. Specifically, the module includes: an image acquisition component 101, a laser 102, a three-axis vibration sensor 103, and an anti-vibration bracket 104, wherein: the laser 102 projects a light spot onto the road surface to be measured; the image acquisition component 101 is installed coplanarly with the laser 102 to acquire an image of the light spot projected by the laser 102 on the road surface to obtain a two-dimensional laser stripe image; the three-axis vibration sensor 103 monitors the three-axis offset amount and the pitch angle of the roller brought to the road surface flatness measurement module 1 by the vibration of the roller steel wheel; the anti-vibration bracket 104 is installed on the roller and is used to fix the laser 102, the image acquisition component 101, and the three-axis vibration sensor 103. The anti-vibration bracket 104 is provided with a shock-absorbing structure to ensure the stability of the laser 102, the image acquisition component 101, and the three-axis vibration sensor 103.

[0035] In the above embodiment of the present utility model, referring to Figure 2As shown in the figure, the road surface flatness measurement module 1 is installed on the roller. Specifically, it can be installed at the rear end of the roller. The laser 102 projects a light spot onto the road surface to be measured (such as an asphalt road surface). The image acquisition component 101 acquires the light spot, and the obtained image, together with the three-axis offset obtained by the three-axis vibration sensor 103 and the pitch angle of the roller, can form accurate three-dimensional data. In the embodiment of the present invention, the measurement is completed during the working process of the roller, and while being free from the vibration interference of the roller, it realizes real-time and accurate flatness measurement of the rolled section. Since the real-time detection is carried out during the construction, it can provide the construction personnel with a reference for the real-time road surface compaction condition, facilitating timely and accurate recompaction and correction, ensuring the road surface flatness quality during the construction stage, realizing process detection, and avoiding quality rework problems.

[0036] In order to enable the image acquisition component 101 to obtain better images, the laser 102 can adopt a line structured light laser 102. In some embodiments, the line structured light laser 102 can adopt an infrared specific band (such as 808nm - 940nm) with weak outdoor sunlight monochromatic radiation force to weaken the interference of sunlight on line laser imaging, thereby making the image quality higher. At the same time, the one-dimensional line light spot projected by the line structured light laser 102 on the road surface is perpendicular to the rolling direction of the roller, and its length can cover the rolling range, realizing the road surface profile scanning in the driving direction of the roller.

[0037] The laser 102 projects a "one" - shaped laser line on the road surface. When the laser line hits an uneven object to be measured, the originally straight laser line will appear to be bent and deformed. The camera will take pictures of the road surface containing the laser line at a certain frame rate. When the one - dimensional laser line irradiates on the uneven road surface, it is imaged in the camera as a continuously undulating laser line. These undulations are the three - dimensional stereo information of the road surface contained in the line stripes.

[0038] Refer to Figure 1 As shown in the figure, in the above - mentioned embodiment, the image acquisition component 101 can be a camera or other image acquisition components. The image acquisition component 101 is arranged above the laser 102 and forms an angle with it. In some embodiments, the image acquisition component 101 can adopt an industrial camera. Among them, the field of view of the industrial camera can cover the complete line light spot projected by the line structure laser 102 on the road surface, and the specific angle between it and the laser 102 is the optimal angle optimized through calibration. In this embodiment, the two - dimensional laser stripe image of the road surface can be obtained through the image acquisition component 101. In one embodiment, the industrial camera adopts a special lens, such as a fish - eye lens, which has a large field of view and can ensure that the complete "one" - shaped laser line is imaged. Using an ordinary lens at this distance can only image 2 / 3 of the laser line, with a smaller measurement range, which will cause inconvenience in subsequent stitching of the complete road surface three - dimensional topography data or complex processing.

[0039] In addition, in order to obtain a high-quality two-dimensional laser stripe image, based on the line structure laser 102, in a preferred embodiment, the industrial camera is provided with an infrared band filter identical to the line structure laser 102. The infrared band filter is placed inside the industrial camera to increase the imaging contrast of the line laser spot and enhance the anti-sunlight interference ability. The infrared filter should be consistent with the wavelength band of the laser, which is also 808 nm to 940 nm. The specific values of both should be the same to achieve the best imaging. The value of this wavelength band in the monochromatic radiant power of sunlight is relatively low, thereby weakening the influence of sunlight on laser imaging. The distance and the included angle between the industrial camera 101 and the line structure laser 102 are confirmed after calibration and optimization. For example, by continuously changing the included angle for reconstruction experiments, the angle corresponding to the best result is the optimal angle.

[0040] Generally speaking, an industrial camera mainly includes an image sensor, a camera circuit board, and a lens. Among them, the image sensor is the core component of the industrial camera, and usually a CMOS or CCD sensor is adopted. The camera circuit board includes an image sensor control chip, A / D conversion, USB or GigE interfaces, etc. The lens is responsible for focusing the light reflected by the object onto the image sensor. The infrared band filter is set behind the industrial camera lens and in front of the image sensor, that is, between the two. The light will first pass through the lens, then through the filter, and then reach the image sensor. The conventional method of installing the filter is to install it on the lens, but the installation method in this embodiment can collimate the light to a certain extent, resulting in a better imaging effect.

[0041] In the prior art, although there are also measurement modules for road surface flatness, many devices only use a measurement in an ideal state and do not consider the influence and error caused by the movement of the actual roller during operation on the measurement module. To solve this problem, referring to Figure 1 、 Figure 2 As shown, in the embodiment of the present invention, the road surface flatness measurement module is installed at the center position of the rear end of the roller and above the steel wheel, and the anti-vibration bracket 104 is installed at the center position of the rear end of the roller. In the present invention, the anti-vibration bracket 104 is used to install the entire measurement module, which can reduce the influence brought by the working movement of the roller itself, making the measurement result more accurate. Through this installation method, the road surface flatness measurement module can optimize the measurement distance to 1.5 m while ensuring the measurement accuracy, away from the high-temperature road surface, and can be well applied to detecting the flatness during the road surface compaction process, thereby ensuring the stability of the road surface flatness measurement module when working in a harsh environment.

[0042] In some embodiments, the anti-vibration bracket 104 adopts a shock absorber 1041 and a shock-absorbing rubber 1042, and absorbs the impact generated by the vibration of the roller steel wheel through a wire shock-absorbing structure and the shock-absorbing rubber, reducing the influence of vibration on the sensors on the bracket. The shock absorber 1041 can be arranged in an array. In one embodiment, such asFigure 3 As shown, it is a partially enlarged schematic diagram of the anti-vibration support. The black part is the wire shock absorber 1041, and each shock absorber 1041 has 8 strands of wire ropes and 2 fixing planes. The gray part is the shock-absorbing rubber 1042. Figure 3 This is a side view. Only a single row of shock absorbers can be seen. In fact, there can be multiple rows of wire shock absorbers. For example, two rows can be adopted, that is, 4x2 shock absorbers are arranged and fixed. The shock absorbers fix the roller and the flatness detection module through screws. At the same time, the shock-absorbing rubber 1042 is filled between the shock absorbers and the roller and the flatness detection module to further absorb vibration (the screw heads are embedded in the fixing planes of each shock absorber).

[0043] In order to obtain the three-axis offset of the road surface flatness measurement module and the pitch angle of the roller, in some embodiments, the three-axis vibration sensor 103 has an angular resolution of <0.01°. The three-axis vibration sensor 103 measures the millimeter-level displacement of the x, y, and z axes, and uses the <0.01° angular resolution of the three-axis vibration sensor 103 to monitor in real time the angular changes generated by the pitch of the flatness detection module at the end of the roller, especially to monitor the three-axis offset and the pitch angle of the roller caused by the vibration of the roller steel wheel to the flatness measurement. In specific applications, the three-axis vibration sensor includes an accelerometer and an inclinometer, and can measure the vibration direction, amplitude, displacement, speed, and the change of the angle at the installation location. For example, the three-axis vibration sensor can be a commercially available three-axis vibration sensor, which includes an accelerometer and an inclinometer inside, and can directly measure the vibration speed, displacement, amplitude, frequency, and angle in the xyz axis directions when installed on the roller. Exemplarily, the vibration frequency of the roller is 30Hz - 60Hz, and the upper limit of the vibration measurement of the three-axis vibration sensor is 100Hz, which can measure and record the three-axis offset and the corresponding moment of each vibration. Subsequently, as long as the laser three-dimensional data corresponding to this moment is found, the offset correction can be performed on it.

[0044] Refer to Figure 4 As shown, in another embodiment of the present invention, a road surface flatness detection device is further provided, which includes a road surface flatness measurement module 1 and a differential positioning module 2. The road surface flatness measurement module 1 is installed on the roller, and the differential positioning module 2 is arranged on the roller body. Among them, in the road surface flatness measurement module 1, the three-axis vibration sensor monitors the three-axis offset and the pitch angle of the roller steel wheel vibration to the measurement system. The differential positioning module 2 determines the coordinates, speed, and direction of the roller in real time through the principle of differential positioning. These information can be transmitted to subsequent processing.

[0045] In a preferred embodiment, the road surface flatness detection device may further include a processing terminal. The output ends of the road surface flatness measurement module 1 and the differential positioning module 2 are both connected to the processing terminal, and the processing terminal is used to process the data obtained by the road surface flatness measurement module 1 and the differential positioning module 2, so as to output the final comprehensive road surface flatness index and the road surface three-dimensional data.

[0046] In some embodiments, the differential positioning module 2 can achieve centimeter-level measurement accuracy, and can calculate the coordinates, speed and direction of the roller in real time, and serve as the data splicing basis for the three-dimensional reconstruction of the road surface. The differential positioning module 2 can be implemented by using commercially available products, such as a GPS differential positioning module.

[0047] In the above embodiment, the triaxial vibration sensor 103 can measure the millimeter-level displacement in the x, y, and z axes, output it to the processing terminal, correct the point cloud data measured by the road surface flatness measurement module in real time, and use the triaxial vibration sensor 103 to monitor the angle change generated by the pitch of the flatness detection module at the end of the roller with an angular resolution of <0.01°, and also feedback it to the processing terminal as the data calibration basis.

[0048] In the above embodiment, the road surface flatness measurement module 1 can adopt Figure 1 , 2 the road surface flatness measurement module shown, which will not be elaborated here.

[0049] In the road surface flatness detection device of the embodiment of the present invention, the road surface flatness measurement module is installed at the center position of the rear end of the roller and above the steel wheel. With the anti-vibration bracket 104 and the triaxial vibration sensor 103, the influence of the steel wheel vibration and the vehicle end pitch angle is eliminated, and the flatness information of the rolled section is measured in real time. The processing terminal 3 can be located in the cab of the roller, display the three-dimensional topography of the road surface and the corresponding flatness information, provide accurate guidance on the road surface compaction condition for the construction personnel, and timely re-roll and correct the sections with unqualified flatness.

[0050] In the embodiment of the present invention, the processing terminal 3 is a terminal with certain data processing capabilities, which can be a computer, a smart phone, etc. Based on the above detection device, the processing terminal 3 adopts the laser triangulation principle, reconstructs the three-dimensional topography of the road surface in real time according to the two-dimensional laser stripe image collected by the image acquisition component in the road surface flatness measurement module 1, and at the same time calibrates the three-dimensional data according to the triaxial offset and pitch angle change feedback by the inertial measurement unit, splices the data according to the coordinates, speed and direction data of the roller measured by the differential positioning module 2 to obtain the complete three-dimensional topography of the road surface, and finally performs cross-section and longitudinal-section analysis to obtain the comprehensive road surface flatness index and display it on the screen together with the road surface three-dimensional data.

[0051] Specifically, in a specific embodiment, when the road surface flatness detection device is working specifically: after the roller is started, the road surface flatness detection device as a whole is automatically powered on and starts to operate stably. When the road rolling operation starts, the driver can control the flatness detection module 1 to start detection through the processing terminal 3. When the road rolling operation ends, the flatness detection module 1 is also controlled to stop detection through the processing terminal 3. During this period, the operator can judge the sections that still do not meet the standards after rolling by observing the three-dimensional information and flatness index of the road surface displayed on the processing terminal 3, and accurately re-roll according to the information. When the processing terminal 3 shows that the flatness of the rolled sections meets the standards, the operation can be ended.

[0052] The structure and working principle of the road surface roughness measurement module 1 are as follows: Figure 1 , 2 As shown, the flatness detection module 1 includes an industrial camera 101, a linear structure laser 102, a three-axis vibration sensor 103 and an anti-vibration bracket 104. When the road surface flatness measurement module receives a start acquisition instruction from the processing terminal 3, the industrial camera 101, the linear structure laser 102 and the three-axis vibration sensor 103 automatically start working, the linear structure laser 102 projects a straight line laser on the road surface, the industrial camera 101 performs imaging acquisition on the line spot, and transmits the obtained image data to the processing terminal 3, while the three-axis vibration sensor 103 records the three-axis displacement data and the device pitch angle data when the current frame is collected, and also transmits them to the processing terminal 3 for processing, so as to calculate and generate accurate results to eliminate the influence of vibration.

[0053] The detection principle of the detection device including the processing terminal 3 of the utility model is as follows:

[0054] In the road surface flatness measurement module, the laser 102 projects a straight laser line on the asphalt road surface. The laser line, which should be a straight line, will show different degrees of bending deformation due to the undulation of the road surface. When the industrial camera images the laser line at different angles from the laser, the deformation degree of the captured laser line spot in the image can be represented by the change in the position of the laser line pixel. According to the laser triangulation method, knowing the pixel coordinates of the laser line in the two-dimensional image can obtain the spatial three-dimensional coordinates of each point on the road surface hit by the laser line. Therefore, the road surface laser line image collected by the industrial camera can reconstruct a road surface cross-section curve (three-dimensional) composed of countless three-dimensional points on the road surface. However, due to the vibration of the roller, the road surface flatness measurement module will have different degrees of offset in the x, y, and z directions (mainly the z axis), and the pitch angle will change with the ups and downs of the vehicle body. In the embodiment of the utility model, the detection device performs point cloud position correction on this cross-sectional curve based on the three-axis offset and pitch angle at the time of collecting the line laser image measured by the three-axis vibration sensor (industrial camera collection and inertial unit measurement can be controlled to be triggered simultaneously), so as to obtain the correct cross-sectional curve, thereby ensuring the accuracy of the measurement data.

[0055] As the roller advances and the industrial camera captures images at a frame rate, multiple road cross-section curves can be continuously reconstructed along the traveling direction. These cross-section curves (formed by point clouds) are spliced according to the coordinate changes of the roller feedback by the differential positioning module, that is: confirm the spacing between each cross-section curve. The positioning accuracy of the differential positioning module is centimeter-level. The differential positioning, camera capture, and triaxial vibration sensor detection are all triggered simultaneously, and finally, a complete three-dimensional road surface (formed by countless point clouds) is spliced.

[0056] After obtaining the complete three-dimensional road surface, any point cloud can be selected for analysis. Specifically, in one embodiment, the processing operation of the processing terminal 3 is as follows: First, the three-dimensional road surface is evenly divided into N segments longitudinally, and each segment of the three-dimensional road surface is further longitudinally sliced N times to obtain N longitudinal section curves. The power spectral density PSD and the international roughness index IRI are calculated for these N longitudinal section curves and averaged (the calculation formulas of PSD and IRI are existing), and the average roughness index of the N segments of the road surface is obtained and displayed on the screen. The operator can perform precise recompression according to the content displayed on the screen. N is a natural number greater than 2, such as 100.

[0057] Exemplarily, the roller starts to advance and roll, the laser line is projected on the asphalt road surface after rolling, and the industrial camera starts to automatically and continuously capture images. The industrial camera, triaxial vibration sensor, and differential positioning component are all triggered to work simultaneously, that is, when the industrial camera captures a line laser image, the triaxial vibration sensor records the triaxial displacement and the vehicle body pitch angle caused by the vibration at that time, and the differential positioning records the position of the roller at that time. The laser line image, triaxial displacement, pitch angle, and differential positioning coordinates at the same moment can be grouped as a set of data. These data are transmitted to the processing terminal 3. The processing terminal 3 calculates an accurate road cross-section curve according to the laser triangulation method and combines the triaxial displacement and pitch angle of the vibration at that time. Then, it continues to process the next set of transmitted data and splices the cross-section curves of each group according to the change of the differential positioning coordinate value (which can be achieved by existing technologies). When the roller stops advancing and is ready to reverse and recompress, the road surface flatness measurement module obtains a complete three-dimensional data of the rolled asphalt road surface. The processing terminal 3 evenly divides the three-dimensional road surface into 100 segments longitudinally, and each segment of the three-dimensional road surface is further longitudinally sliced 100 times to obtain 100 longitudinal section curves. The power spectral density PSD and the international roughness index IRI are calculated for these 100 longitudinal section curves and averaged (the calculation can use existing technologies), and the average roughness index of the 100 segments of the road surface is obtained and displayed on the screen. The operator can perform precise recompression according to the content displayed on the screen.

[0058] In the road surface evenness detection device in the above embodiments of the present utility model, based on the road surface evenness measurement module 1, it can realize real-time and accurate evenness measurement of the rolled section while being free from the vibration interference of the roller, and at the same time obtain the complete three-dimensional road surface topography and visualize it, providing real-time reference for the road surface compaction condition for construction personnel, facilitating timely and accurate recompaction correction. Further, through the processing terminal 3 to realize data visualization, it can also guide production construction, ensure a high evenness index at the road production stage, improve construction quality, greatly reduce the probability of rework, and at the same time provide data traceability for road digitization.

[0059] It can be understood that the influence of the regular vibration during the operation of the roller on the measurement can be jointly eliminated by the triaxial vibration sensor 103 and the anti-vibration bracket 104. The anti-vibration bracket 104 is internally provided with a wire shock-absorbing structure and shock-absorbing rubber, which can ensure the relative stability of the road surface evenness measurement module 1. The triaxial vibration sensor 103 can accurately measure the triaxial offset of the roller to the road surface evenness measurement module 1 and feedback it to the terminal 3 to correct each frame of the reconstructed three-dimensional road surface information, achieving the effect of eliminating the vibration influence. The processing terminal 3 uses the relative position information of the calibrated industrial camera 101 and the line structure laser 102, and uses the laser triangulation method to perform three-dimensional reconstruction on each frame of the line spot image returned by the road surface evenness measurement module 1, combines the triaxial offset measured by the triaxial vibration sensor 103 to correct each frame result, obtains accurate single-frame three-dimensional road surface data, and stitches each frame result according to the driving speed read by the differential positioning module 2 for the real-time positioning of the roller, generates complete three-dimensional road surface data, and at the same time performs transverse and longitudinal section analysis on the three-dimensional data to calculate the corresponding evenness index.

[0060] For example, when the roller starts the rolling operation on the section, the operator controls the road surface evenness measurement module 1 to start detection through the processing terminal 3. The industrial camera 101 continuously collects at a certain frame rate. The line spot projected by the line structure laser 102 on the rolled road surface is imaged and collected by the industrial camera 101 and transmitted to the processing terminal 3. The processing terminal 3 reconstructs the three-dimensional road surface data of this frame through the laser triangulation method, and corrects the result according to the triaxial offset and the pitch angle of the roller returned by the triaxial vibration sensor 103 when collecting the current frame, obtaining an accurate frame of three-dimensional road surface data. When reconstructing and correcting the three-dimensional data of the next frame, the processing terminal 3 reads the coordinates, speed and direction information of the roller of the differential positioning module 2 as the stitching basis between the two frames of three-dimensional data. Repeating this way, when the rolling operation on the section is completed, the operator controls the road surface evenness measurement module 1 to end the detection through the processing terminal 3. At the same time, the processing terminal 3 performs transverse and longitudinal section analysis on the three-dimensional data of this section to calculate the comprehensive evenness index and displays it on the screen together with the three-dimensional road surface data for the operator to refer to and decide on the recompaction operation.

[0061] The specific embodiments of the present utility model have been described above. It should be understood that the present utility model is not limited to the above specific embodiments, and those skilled in the art can make various deformations or modifications within the scope of the claims, which does not affect the essence of the present utility model. The above preferred features can be used in any combination without conflict.

Claims

1. A road surface flatness measurement module, which is installed on a road roller and completes the measurement during the operation of the road roller, characterized in that: include: A laser, projecting a straight laser line onto the road surface to be tested, forming a light spot on the road surface to be tested; An image acquisition component is installed coplanar with the laser, and the image acquisition component acquires the light spot projected by the laser on the road surface to obtain a two-dimensional image of the laser stripes; A three-axis vibration sensor is used to monitor the three-axis offset and the pitch angle of the roller caused by the vibration of the roller wheel to the road surface flatness measurement module; An anti-vibration bracket is installed on the roller and is used to fix the laser, image acquisition component and three-axis vibration sensor. The anti-vibration bracket is provided with a shock-absorbing structure to ensure the stability of the laser, image acquisition component and three-axis vibration sensor.

2. The road surface flatness measurement module according to claim 1, characterized in that: The road surface flatness measurement module is installed in the middle of the rear end of the roller and above the steel wheel; The anti-vibration bracket is installed at the center of the rear end of the roller; The image acquisition component is arranged above the laser and forms an angle with the laser.

3. The road surface flatness measurement module according to claim 1, characterized in that: The laser is a line structured light laser, which projects a line spot of light on the road surface perpendicular to the rolling direction of the roller, and the length of the line spot covers the rolling range, thereby realizing road surface scanning in the driving direction of the roller.

4. The road surface flatness measurement module according to claim 3, characterized in that: The image acquisition component is provided with an infrared band filter which is the same as that of the linear structure laser, and the infrared band filter is placed inside the image acquisition component.

5. The road surface flatness measurement module according to claim 4, characterized in that: The image acquisition component adopts an industrial camera, which includes an image sensor, a camera circuit board and a lens, and the lens adopts a fisheye lens.

6. The road surface flatness measurement module according to claim 5, characterized in that: The infrared band filter is arranged behind the lens of the industrial camera and in front of the image sensor. The light first passes through the lens and then reaches the image sensor through the infrared band filter.

7. The road surface flatness measurement module according to claim 1, characterized in that: The shock absorbing structure is a shock absorber and a shock absorbing rubber, wherein the shock absorber is arranged in an array, each of the shock absorbers fixes the roller and the road surface flatness measuring module through a connecting piece, and the shock absorbing rubber is arranged between the shock absorber and the roller and the road surface flatness measuring module.

8. The road surface flatness measurement module according to claim 1, characterized in that: The triaxial vibration sensor comprises an accelerometer and an inclinometer, and is mounted on the roller; The three-axis vibration sensor is a sensor for obtaining three-axis millimeter-level displacement, and the three-axis vibration sensor has an angular resolution of <0.01°.

9. A road surface flatness detection device, characterized in that: include: The road surface flatness measurement module according to any one of claims 1 to 8; The differential positioning module is arranged on the roller body.

10. The road surface flatness detection device according to claim 9, characterized in that: It also includes a processing terminal, the output ends of the image acquisition component and the three-axis vibration sensor in the road surface flatness measurement module are connected to the processing terminal, and the output end of the processing terminal is connected to the display module.

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