A device for quickly detecting the height difference of misaligned blocks of cement concrete pavement

Abstract

The application discloses a kind of cement concrete pavement slab misalignment high difference rapid detection device, with such characteristics, comprising: detection vehicle;Camera module is used to collect road surface image data, and is arranged on detection vehicle;Laser ranging module is installed in the chassis of detection vehicle, and laser ranging module at least includes acceleration sensor and laser ranging sensor, acceleration sensor is used to collect vehicle vibration data, and laser ranging sensor is used to collect road surface elevation data;And positioning module at least includes photoelectric encoder, photoelectric encoder is fixed on the rear wheel of detection vehicle median axis, for measuring the driving length of detection vehicle.The principle is to draw the relative elevation curve of 0.2m range road surface longitudinal section before and after joint by laser ranging sensor and acceleration sensor, automatically identify and calculate the joint height difference of cement concrete pavement by detection algorithm, quantitatively describe the misalignment severity of the section, and quickly locate, facilitate timely maintenance, to improve the driving comfort of road.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of road detection, in particular to a cement concrete pavement slab misalignment height difference rapid detection device. BACKGROUND

[0002] Cement concrete material has the characteristics of rigidity, strong load diffusion capacity, and good stability, and was widely used in road construction in the 1990s. The cement concrete pavement constructed at that time has been close to the end of the designed service life, and pavement diseases occur frequently. Misalignment of slab joints is one of the more prominent diseases. Misalignment can cause vehicle bumping and affect driving comfort. With the development of society and the gradual improvement of people's demand for travel quality, it is an important task in the field of road traffic management to eliminate the impact of misalignment disease on existing cement concrete pavement.

[0003] Currently, the commonly used method for misalignment height difference detection is to measure manually with a ruler under the condition of closed traffic, which is not only inefficient but also affects traffic operation. Some methods use vehicle-mounted vibration sensors to measure vehicle amplitude to evaluate misalignment, but this method can only evaluate the severity of different misalignments, cannot measure misalignment height difference, and cannot distinguish whether the abnormal vibration of the vehicle is caused by misalignment. SUMMARY

[0004] The present application is made to solve the above problems, and aims to provide a cement concrete pavement slab misalignment height difference rapid detection device.

[0005] The present application provides a cement concrete pavement slab misalignment height difference rapid detection device, which has the following characteristics: a detection vehicle; a camera module for collecting road surface image data, arranged on the detection vehicle; a laser ranging module installed on the chassis of the detection vehicle, the laser ranging module comprising at least an acceleration sensor and a laser ranging sensor, the acceleration sensor being used to collect vehicle vibration data, and the laser ranging sensor being used to collect road surface elevation data; and a positioning module comprising at least an optical encoder fixed on the rear wheel centerline of the detection vehicle, used to measure the driving length of the detection vehicle.

[0006] In the cement concrete pavement slab misalignment height difference rapid detection device provided by the present application, the camera module can further comprise a foreground camera unit and a background camera unit, the foreground camera unit being arranged in front of the detection vehicle, and the background camera unit being arranged behind the detection vehicle.

[0007] In the cement concrete pavement slab staggered platform height difference rapid detection device provided by the application, the foreground camera unit can further have the following features: the foreground camera unit comprises a right-angle camera and a front-angle camera. The front-angle camera is horizontally arranged on the front of the detection vehicle and faces forward. The right-angle camera is arranged on the front of the detection vehicle and is located above the front-angle camera, and the camera is obliquely downward and forms a 45° angle with the forward direction of the detection vehicle. The rear camera unit comprises a rear high-definition camera, a first metal protection box and a bracket. The bracket is in the shape of a Chinese character "7" and is arranged at the tail of the detection vehicle. The first metal protection box is arranged at the tail of the bracket, the bottom is designed to be openable, and a square hole is reserved at the bottom. The rear high-definition camera is arranged in the first metal protection box, and the camera faces vertically downward to the ground.

[0008] In the cement concrete pavement slab staggered platform height difference rapid detection device provided by the application, the laser ranging module can further have the following features: the laser ranging module comprises a first rigid beam, a second rigid beam, a third rigid beam, two second metal protection boxes, two acceleration sensors and two laser ranging sensors. The first rigid beam and the second rigid beam are arranged at the left and right wheel positions of the chassis of the detection vehicle respectively, and are arranged in the same straight line as the forward direction of the detection vehicle. The third rigid beam is arranged at the front of the chassis of the detection vehicle, and is perpendicular to the first rigid beam and the second rigid beam. The front ends of the first rigid beam and the second rigid beam are fixedly connected with the third rigid beam. The two second metal protection boxes are fixedly arranged at the two ends of the third rigid beam respectively, and the bottom of the second metal protection box is designed to be openable and a square hole is reserved at the bottom. An acceleration sensor and a laser ranging sensor are arranged in each second metal protection box.

[0009] In the cement concrete pavement slab staggered platform height difference rapid detection device provided by the application, the photoelectric encoder can further have the following features: the photoelectric encoder records the number of rotations of the wheels of the detection vehicle, and calculates the driving length of the detection vehicle according to the wheel circumference of the detection vehicle.

[0010] In the cement concrete pavement slab staggered platform height difference rapid detection device provided by the application, the device can further have the following features: a power module is arranged for supplying power to the camera module, the laser ranging module and the positioning module; and a data line is arranged. The power module is connected with the camera module, the laser ranging module and the positioning module through the data line.

[0011] In the cement concrete pavement slab staggered platform height difference rapid detection device provided by the application, the device can further have the following features: a central computer is arranged in the detection vehicle and is connected with the camera module, the laser ranging module and the positioning module through the data line, and is used for controlling the work of each module and collecting, processing and analyzing data.

[0012] In the cement concrete pavement slab block misalignment height difference rapid detection device provided by the application, the working process of the central computer can further have the following characteristics: step 1, according to the image data generated by the camera module and the driving mileage data recorded synchronously by the positioning module, the center stake number of each collected image is marked to obtain a marking result; step 2, based on the marking result, the collected color image is converted into a 256-color gray scale image, and a vertical direction projection is performed on the image to obtain a gray scale value of the image; step 3, based on the gray scale value, a Kirsch edge calculation method is used to calculate the difference value of the image from 8 different directions, the maximum value obtained by the calculation is taken as the edge strength, and the direction of the maximum value is taken as the edge direction; step 4, based on the edge strength and the edge direction, a maximum entropy image segmentation algorithm is used to solve the threshold T of each frame of picture segmentation, the binary processing of the gray scale image is completed, and the lines in the gray scale image are recognized; step 5, the lines in the gray scale image are connected by using the Hough transformation to realize the rapid positioning of the slab joint in the image, the coordinates of the slab joint in the road are further determined in combination with the coordinates of the image itself, and the concrete slab joint stake number is obtained; and step 6, the misalignment height detection is performed on the 0.2 m before and after the concrete slab joint stake number.

[0013] In the cement concrete pavement slab block misalignment height difference rapid detection device provided by the application, the working process of the central computer can further have the following characteristics: in step 4, the solving formula of the threshold T is as follows:

[0014]

[0015]

[0016]

[0017]

[0018] In the formula, p i is the probability of the gray scale value i in the gray scale image, P Bi is the probability density between the gray scale values 0-T, P Fi is the probability density between the gray scale values T+1-255, and P T is the probability between the gray scale values 0-T.

[0019] In the cement concrete pavement slab block misalignment height difference rapid detection device provided by the application, the working process of the central computer can further have the following characteristics: in step 6, the steps of the misalignment height detection are as follows: step 6-1, the acceleration measured by the acceleration sensor in the range of 0.2 m before and after the concrete slab joint stake number is filtered to filter out the high-frequency components of the acceleration data, so as to obtain a new acceleration signal a = [a1, a2, a3…a n-1 , and step 6-2, the new acceleration signal is differentiated to obtain a new acceleration signal a = [a1, a2, a3…an ];Step 6-2, extracting the laser measured road elevation data of each 0.2m before and after the concrete pavement slab block joint, the laser measured road elevation data h = [h1, h2, h3…h n-1 , h n ];Step 6-3, calculating the road relative elevation data H = [H1, H2, H3…H n-1 , H n ] based on the road elevation data, assuming that the contact surface of the wheel and the road is the height 0 point, and the road relative elevation data of each measuring point is as follows:

[0020] H = h - ∫∫0 t adt

[0021] In the formula, t = 1 / f, and f is the sampling frequency of the laser range finder and the acceleration sensor. The joint heave difference is the range of the relative elevation within each 0.2m before and after the joint, and the calculation formula is:

[0022] ΔH = max(H) - min(H).

[0023] Effects of the application

[0024] According to the cement concrete pavement slab block heave difference rapid detection device, the device comprises a detection vehicle, a camera module for collecting road image data, a laser ranging module installed on the chassis of the detection vehicle, the laser ranging module comprising at least an acceleration sensor and a laser ranging sensor, the acceleration sensor being used to collect vehicle vibration data, and the laser ranging sensor being used to collect road elevation data, and a positioning module comprising at least an optical encoder fixed on the rear wheel center line of the detection vehicle and used to measure the driving length of the detection vehicle.

[0025] Therefore, according to the cement concrete pavement slab block heave difference rapid detection device, the acceleration sensor and the laser ranging sensor are combined for use, so that the road longitudinal section elevation change can be measured under the condition of eliminating the self-vibration of the vehicle, and the road longitudinal section elevation difference can be accurately obtained.

[0026] In addition, the optical encoder can be used to locate the position of the starting point of the vehicle in real time, and a high-definition camera can be used to shoot the road picture, and the intelligent recognition algorithm can be used to effectively identify and locate the joint position coordinates of the cement concrete pavement slab block, so that other influencing factors can be eliminated, and only the elevation difference of the joint position of the cement slab block can be output. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 is the overall schematic diagram of the cement concrete pavement slab block heave difference rapid detection device in the embodiment of the application;

[0028] Figure 2 is a schematic view of the foreground camera unit in an embodiment of the present application; and

[0029] Figure 3 is a top view of the laser ranging module in an embodiment of the present application. DETAILED DESCRIPTION

[0030] In order to make the technical means, creative features, purposes and effects of the present application easy to understand, the following embodiments will be described in detail with reference to the accompanying drawings.

[0031] The present embodiment provides a cement concrete pavement slab staggered bench high difference rapid detection device 100.

[0032] Figure 1 is a schematic view of the overall cement concrete pavement slab staggered bench high difference rapid detection device in an embodiment of the present application.

[0033] As shown in Figure 1 , the cement concrete pavement slab staggered bench high difference rapid detection device 100 in the present embodiment includes a detection vehicle 10, a camera module 20, a laser ranging module 30, a positioning module 40, a power supply module (not shown in the figure), a data line 50 and a central computer 60.

[0034] The camera module 20 is used to collect road surface image data and is arranged on the detection vehicle 10. The camera module 20 includes a foreground camera unit 21 and a background camera unit 22. The foreground camera unit 21 is arranged in front of the detection vehicle 10, and the background camera unit 22 is arranged behind the detection vehicle 10.

[0035] Figure 2 is a schematic view of the foreground camera unit 21 in an embodiment of the present application.

[0036] As shown in Figure 1 and Figure 2 , the foreground camera unit 21 includes a right angle camera 211 and a front camera 212. The front camera 212 is horizontally arranged on the front of the detection vehicle 10, and the camera head is directed straight ahead. The right angle camera 211 is arranged on the front of the detection vehicle 10 and is located above the front camera 212, and the camera head is obliquely downward and forms a 45° angle with the forward direction of the detection vehicle 10.

[0037] The background camera unit 22 includes a rear high-definition camera 221, a first metal protection box 222 and a bracket 223. The bracket 223 is in the shape of a "7" and is arranged at the tail of the vehicle. The first metal protection box 222 is arranged at the tail of the bracket 223, the bottom is designed to be openable, and a square hole is reserved at the bottom. The rear high-definition camera 221 is arranged inside the first metal protection box 222, and the camera head is vertically downward towards the ground.

[0038] Figure 3 is a top view of the laser ranging module in the embodiment of the present application.

[0039] As shown in Figure 1 and Figure 3 The laser ranging module 30 is installed on the chassis of the detection vehicle 10. The laser ranging module 30 includes a first rigid crossbeam 31, a second rigid crossbeam 32, a third rigid crossbeam 33, two second metal protective boxes 34, two acceleration sensors 35, and two laser ranging sensors 36. The acceleration sensors 35 are used to collect vehicle vibration data, and the laser ranging sensors 36 are used to collect road elevation data.

[0040] The first rigid crossbeam 31 and the second rigid crossbeam 32 are respectively arranged at the left and right wheel positions of the chassis of the detection vehicle 10, and are in the same straight line as the forward direction of the detection vehicle 10. The third rigid crossbeam 33 is arranged at the front of the chassis of the detection vehicle 10, and is perpendicular to the first rigid crossbeam 31 and the second rigid crossbeam 32. The front ends of the first rigid crossbeam 31 and the second rigid crossbeam 32 are fixedly connected to the third rigid crossbeam 33.

[0041] The two second metal protective boxes 34 are respectively fixed at the two ends of the third rigid crossbeam 33. The bottom of the second metal protective box 34 is designed to be openable, and a square hole is reserved at the bottom. An acceleration sensor 35 and a laser ranging sensor 36 are placed in each second metal protective box 34.

[0042] The positioning module 40 includes an optical encoder 41 fixed on the rear wheel center axis of the detection vehicle 10, which is used to measure the driving length of the detection vehicle 10. The optical encoder 41 measures the driving length of the detection vehicle 10 by recording the number of revolutions of the wheels of the detection vehicle 10 and calculating the circumference of the wheels of the detection vehicle 10.

[0043] The power supply module is used to supply power to the camera module 20, the laser ranging module 30, and the positioning module 40. The power supply module is connected to the camera module 20, the laser ranging module 30, and the positioning module 40 through the data line 50.

[0044] The central computer 60 is located inside the detection vehicle 10 and is connected to the camera module 20, the laser ranging module 30, and the positioning module 40 through the data line 50 for communication. The central computer 60 is used to control the work of each module and collect, process, and analyze data.

[0045] The working process of the central computer 60 is as follows:

[0046] Step S1, according to the image data generated by the camera module 20 and the mileage data recorded synchronously by the positioning module 40, the center stake number of each collected image is marked to obtain a marking result.

[0047] Step S2, based on the marking result, the collected color image is converted into a 256-color gray scale image, and a vertical direction projection is performed on the image to obtain a gray scale value of the image.

[0048] Step S3, based on the gray scale value, a Kirsch edge calculation method is used to calculate a difference value from 8 different directions for the image, and the maximum value obtained by the calculation is taken as an edge strength, and the direction of the maximum value is taken as an edge direction.

[0049] Step S4, based on the edge strength and the edge direction, a maximum entropy image segmentation algorithm is used to solve a segmentation threshold T of each frame of picture, and a binary processing of the gray scale image is completed to identify a line in the gray scale image.

[0050] The solving formula of the threshold T is as follows:

[0051]

[0052]

[0053]

[0054]

[0055] In the formula, p i is a probability of the gray scale value i in the gray scale image, P Bi is a probability density between the gray scale values 0-T, P Fi is a probability density between the gray scale values T+1-255, and P T is a probability between the gray scale values 0-T.

[0056] Step S5, the lines in the gray scale image are connected by using a Hough transformation to realize a fast positioning of the slab joints in the image, and the coordinates of the slab joints in the road are further determined in combination with the coordinates of the image itself to obtain a concrete slab joint stake number.

[0057] Step S6, a misaligned height detection is performed on each 0.2m before and after the concrete slab joint stake number.

[0058] The steps of the misaligned height detection are as follows:

[0059] Step S6-1, the acceleration measured by the acceleration sensor 35 in each 0.2m before and after the concrete slab joint stake number is filtered to filter out the high frequency components of the acceleration data, so as to obtain a new acceleration signal a = [a1, a2, a3…a n-1a n ]。

[0060] Step S6-2, extract the concrete pavement slab pile number joint before and after each 0.2m laser measured road elevation data, laser measured road elevation data h = [h1, h2, h3…h n-1 , h n ]。

[0061] Step S6-3, based on the road elevation data to calculate the relative elevation data H = [H1, H2, H3…H n-1 , H n ], the wheel and the road surface as the height of 0 points, each measuring point road relative elevation data as follows:

[0062]

[0063] In the formula, t = 1 / f, f is the laser range finder and acceleration sensor 35 sampling frequency. Joint step difference is the difference between the relative elevation within 0.2m before and after the joint, the calculation formula is:

[0064] ΔH = max(H) - min(H).

[0065] The detection steps of the cement concrete pavement slab step difference rapid detection device 100 in the embodiment are:

[0066] Step one: when the central computer 60 opens the detection mode, the photoelectric encoder 41 installed on the rear wheel of the detection vehicle 10 is initialized to 0, and at the same time, the laser ranging sensor 36, the acceleration sensor 35 installed on the front part of the detection vehicle 10, and the right angle camera 211, the front angle camera 212 and the rear high-definition camera 221 installed on the front and rear positions of the detection vehicle 10 are started.

[0067] Step two: when the detection vehicle 10 starts to move forward, the detection vehicle 10 travel distance is obtained by the photoelectric encoder 41, and the laser ranging sensor 36 and the acceleration sensor 35 collect data once every 0.5cm; high-definition camera collects image data once every 2m.

[0068] Step three: the collected acceleration signal is input into the central computer 60 with the laser ranging sensor 36 signal and the pile number signal for processing, the acceleration signal is filtered to remove noise, and the laser ranging sensor 36 signal is subtracted by twice integration to eliminate the influence of vehicle driving process, and the pile number information is corresponded to obtain the longitudinal section relative elevation of the detection section.

[0069] Step four: the central computer 60 calculates the maximum and minimum difference of the obtained road longitudinal section relative elevation, and outputs the jumping position and the difference.

[0070] Effects of the Embodiment

[0071] According to the cement concrete pavement slab dislocation height difference rapid detection device provided by the embodiment, the acceleration sensor and the laser ranging sensor are combined to measure the elevation change of the pavement longitudinal section under the condition of eliminating the influence of the vehicle self-vibration, and the pavement longitudinal section height difference is accurately obtained.

[0072] Therefore, according to the cement concrete pavement slab dislocation height difference rapid detection device provided by the embodiment, the acceleration sensor and the laser ranging sensor are combined to measure the elevation change of the pavement longitudinal section under the condition of eliminating the influence of the vehicle self-vibration, and the pavement longitudinal section height difference is accurately obtained.

[0073] In addition, the photoelectric conversion encoder can be used to locate the position of the vehicle starting point in real time, and the high-definition camera can be used to shoot the pavement picture, and the intelligent recognition algorithm can be used to effectively identify and locate the position coordinates of the cement concrete pavement slab joint, so that other influencing factors can be eliminated, and only the height difference of the cement slab joint position can be output.

[0074] The above embodiment is a preferred case of the present application and does not limit the protection scope of the present application.

Claims

1. A rapid detection device for the height difference of misaligned cement concrete pavement slabs, characterized in that, include: Inspection vehicle; A camera module, used to collect road surface image data, is installed on the inspection vehicle; A laser ranging module is installed on the chassis of the inspection vehicle. The laser ranging module includes at least an acceleration sensor and a laser ranging sensor. The acceleration sensor is used to collect vehicle vibration data, and the laser ranging sensor is used to collect road surface elevation data. as well as The positioning module includes at least a photoelectric encoder, which is fixed on the rear wheel centerline of the inspection vehicle and is used to measure the travel length of the inspection vehicle. A central computer, located inside the inspection vehicle, is connected to the camera module, the laser ranging module, and the positioning module via data cables. It controls the operation of each module and collects, processes, and analyzes data. The laser ranging module includes a first rigid beam, a second rigid beam, a third rigid beam, two second protective metal boxes, two accelerometers, and two laser ranging sensors. The first and second rigid crossbeams are respectively positioned at the left and right wheel locations of the testing vehicle chassis, with their directions aligned with the forward direction of the testing vehicle. The third rigid crossbeam is positioned at the front of the testing vehicle chassis, with its direction perpendicular to the first and second rigid crossbeams, and the front ends of the first and second rigid crossbeams are fixedly connected to the third rigid crossbeam. The two second protective metal boxes are respectively fixed to both ends of the third rigid crossbeam. The bottom of the second protective metal box is designed to be openable, and a square hole is reserved at the bottom. Each of the second protective metal boxes contains one of the accelerometer sensors and one of the laser rangefinder sensors. The working process of the central computer is as follows: Step 1: Based on the image data generated by the camera module and the driving mileage data synchronously recorded by the positioning module, mark the center station number of each acquired image to obtain the marking result; Step 2: Based on the marking results, the acquired color image is converted into a 256-color grayscale image, and the image is projected vertically to obtain the grayscale value of the image. Step 3: Based on the grayscale value, the Kirsch edge calculation method is used to calculate the difference value of the image from 8 different directions. The maximum value is taken as the edge intensity, and the direction of the maximum value is taken as the edge direction. Step 4: Based on the edge intensity and the edge direction, use the maximum entropy image segmentation algorithm to solve the segmentation threshold T for each frame of the image, complete the binarization process of the grayscale image, and identify the lines in the grayscale image. Step 5: Use Hough transform to connect the lines in the grayscale image to quickly locate the slab joint in the image. Combine the image's own coordinates to further determine the coordinates of the slab joint in the road and obtain the concrete slab joint station number. Step 6: Detect the misalignment height 0.2m before and after the pile number of the concrete slab joint.

2. The rapid detection device for misalignment height difference of cement concrete pavement slabs according to claim 1, characterized in that: in, The camera module includes a foreground camera unit and a background camera unit. The foreground camera is located at the front of the inspection vehicle, and the rear camera is located at the rear of the inspection vehicle.

3. The rapid detection device for misalignment height difference of cement concrete pavement slabs according to claim 2, characterized in that: in, The foreground camera unit includes a right-view camera and a front-view camera. The front-view camera is horizontally mounted on the front of the inspection vehicle, with the camera facing directly forward. The right-side camera is mounted on the front of the inspection vehicle, above the front-view camera, with the camera angled downwards at a 45° angle to the direction of travel of the inspection vehicle. The rear camera unit includes a rear high-definition camera, a first metal protective box, and a bracket. The bracket is shaped like a "7" and is located at the rear of the vehicle. The first metal protective box is located at the rear of the bracket, with an openable bottom and a pre-drilled square hole. The rear high-definition camera is installed inside the first metal protective box, with the camera pointing vertically downwards toward the ground.

4. The rapid detection device for misalignment height difference of cement concrete pavement slabs according to claim 1, characterized in that: in, The photoelectric encoder records the number of rotations of the wheels of the inspection vehicle and calculates the travel distance of the inspection vehicle based on the wheel circumference.

5. The rapid detection device for misalignment height difference of cement concrete pavement slabs according to claim 1, characterized in that, Also includes: A power supply module is used to supply power to the camera module, the laser ranging module, and the positioning module; as well as Data cable The power module is connected to the camera module, the laser ranging module, and the positioning module via the data cable.

6. The rapid detection device for misalignment height difference of cement concrete pavement slabs according to claim 1, characterized in that: in, In step 4, the formula for calculating the threshold T is as follows: In the formula, p i Let P be the probability of grayscale value i in a grayscale image. Bi P represents the probability density of grayscale values ​​between 0 and T. Fi P represents the probability density of grayscale values ​​between T+1 and 255. T This represents the probability of grayscale values ​​between 0 and T.

7. The rapid detection device for misalignment height difference of cement concrete pavement slabs according to claim 1, characterized in that: in, In step 6, the steps for detecting the misalignment height are as follows: Step 6-1: Filter the acceleration data measured by the accelerometer within a 0.2m range before and after the concrete slab joint station number, removing the high-frequency components to obtain a new acceleration signal a = [a1, a2, a3…a…]. n-1 ,a n ]; Step 6-2: Extract the pavement elevation data measured by laser at 0.2m before and after the joint of the concrete pavement slab. The pavement elevation data measured by laser is h = [h1, h2, h3…h n-1 h n ]; Step 6-3: Calculate the relative elevation data of the road surface H = [H1, H2, H3…H2] based on the road surface elevation data. n-1 H n Let the contact surface between the wheel and the road surface be the height 0 point. The relative elevation data of the road surface at each measuring point are as follows: In the formula, t = 1 / f, where f is the sampling frequency of the laser rangefinder and the accelerometer. The difference in elevation between the joints is the range of relative elevations within 0.2m before and after the joint, calculated using the following formula: ΔH = max(H) - min(H).

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