A method for inspecting bulges in asphalt pavement

Abstract

This invention discloses a method for inspecting bulges on asphalt pavements. By adding an acceleration sensor to detect the vertical acceleration of the inspection vehicle, the height and volume of the bulge can be calculated by combining the measured value with parameters such as vehicle speed. The bulge level is determined by comparing it with a preset threshold, and then the maintenance method is determined. This invention can reduce costs, be used for routine inspections, and is not affected by climate.

Description

Technical Field

[0001] This invention relates to the field of road maintenance technology, specifically to a method for inspecting bulges on asphalt pavements. Background Technology

[0002] Swelling defects are caused by the horizontal and vertical displacement of surface aggregates during the use of asphalt pavement, resulting in large-scale surface deformation. This has a significant impact on the stability and comfort of high-speed vehicles. It is characterized by a large affected area, a wide range of impacts, heavy maintenance and repair work, and a tendency to expand and accumulate.

[0003] Currently, existing automated devices using two-dimensional vision processing and linear laser scanning utilize road surface image feature extraction to identify and classify road defects, primarily for potholes and cracks. However, video acquisition methods are significantly affected by weather conditions, easily leading to uneven imaging, shadows, and a lack of longitudinal elevation information, making it difficult to accurately reflect the true extent of the defects. Laser scanning-based detection has a limited single-scan range, requires excessive time for a single inspection, and is costly to operate. Current detection instruments mainly include the inspection vehicle developed by the Australian Scientific and Industrial Research Organisation (CSIRO), the Automatic Road Analyzer platform (ARAN) developed by Fugro NV in the Netherlands, and inspection vehicles developed by Romdas, Pavemetrics, Wuhan Wuda Zhuoyue Technology Co., Ltd., and Zhonggong Gaoke. These are all non-destructive contact measurements based on three-dimensional point cloud laser scanning. Due to their high cost, they are generally used for annual inspections and are difficult to widely implement. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a method for inspecting bulges in asphalt pavements.

[0005] This invention is achieved through the following technical solution:

[0006] A method for inspecting bulges in asphalt pavement.

[0007] Step 1: Drive the test vehicle to the starting point of the test section, turn on the on-board computer, and check whether the on-board computer, acceleration sensor and GPS are in good working order. The acceleration sensor is set on the chassis of the test vehicle along a linear array.

[0008] Step Two: Start the vehicle and drive back and forth on the test section, one lane at a time. When encountering changes in vertical acceleration, the onboard computer automatically starts recording data, including vehicle speed, coordinates, time, and acceleration values ​​collected by each acceleration sensor, as well as the sampling frequency. The sampling period is the reciprocal of the sampling frequency;

[0009] Step 3: Based on the data obtained in Step 2, calculate the maximum bump height of the vertical profile along the forward direction where each accelerometer is located. The formula is as follows: Where H is the maximum crowding height. The average acceleration when driving through the crowd, The average speed at which a vehicle passes through a congestion is given by denoted as T, and the time taken to pass through the congestion is given by denoted as T.

[0010] Step 4: According to the formula Find the crowd height at a given point, where h is the crowd height at that point. In the formula The acute angle between the vehicle and the ground. For instantaneous acceleration, Instantaneous vehicle speed The sampling time interval;

[0011] Step 5: Based on h obtained in each sampling period, obtain the relationship between the pack height and time, and then obtain the shape equation H(t) of the pack along the forward direction. The number of shape equations obtained is equal to the number of accelerometers.

[0012] Step Six: According to the formula The volume of a congestion in a single lane is obtained, where c is the distance between two adjacent accelerometers, n is the number of accelerometers, and T is the time taken to pass through the congestion; then, according to the formula... The volume of a certain congestion packet is obtained, where m is the number of lanes;

[0013] Step 7: Compare the obtained maximum packet height and packet volume with the preset thresholds.

[0014] Preferably, the acceleration sensor is a non-contact acceleration sensor, which is connected to the vehicle computer via a transmission line.

[0015] Preferably, the on-board computer binds the bulge volume, bulge height, and coordinates, and stores them in the on-board computer's database. When the detection vehicle passes the same location again, it automatically calculates the bulge volume and bulge height.

[0016] Preferably, the same road segment should be tested three times in both directions. The range of the three test results should not exceed 10% of the average value. If the range exceeds 10% of the average value, the test should be repeated.

[0017] The beneficial effects of this invention are as follows: This invention uses the centrifugal acceleration value generated when a vehicle passes through the valley peak area to deduce and estimate the valley height and volume of the valley based on the principle of inertia. This helps road maintenance departments to determine the degree of valley damage in a timely manner and accurately grasp the spatial scale of the damage, thereby scientifically formulating maintenance strategies and carrying out timely and effective maintenance work such as planing.

[0018] This invention does not require traffic closures during inspection, making it more efficient than manual inspection, less expensive than automated devices for two-dimensional vision processing and linear laser scanning, and unaffected by weather conditions, making it suitable for routine inspections. Attached Figure Description

[0019] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale.

[0020] Figure 1 This is a schematic diagram of the packet of the present invention.

[0021] Figure 2 This is a schematic diagram of the packet of the present invention.

[0022] Figure 3 for Figure 2 Enlarged view of point A.

[0023] Figure 4 The shape of the curve represents the direction of travel.

[0024] Figure 5 The shape of the curve represents the direction of travel.

[0025] Figure 6 The shape of the curve represents the direction of travel.

[0026] Figure 7 The shape of the curve represents the direction of travel.

[0027] Figure 8 The shape of the curve represents the direction of travel. Detailed Implementation

[0028] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0029] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0030] The present invention will now be described in detail with reference to the accompanying drawings: A method for inspecting bulges in asphalt pavement according to the present invention is as follows:

[0031] Step 1: Drive the test vehicle to the starting point of the test section, turn on the on-board computer, and check whether the on-board computer, acceleration sensor and GPS are working properly. The acceleration sensor is set in a linear array on the chassis of the test vehicle. There are 5 acceleration sensors, and the distance between each acceleration sensor is 30cm.

[0032] Step Two: Start the vehicle and drive back and forth on the test section, one lane at a time. When encountering changes in vertical acceleration, the onboard computer automatically starts recording data, including vehicle speed, coordinates, time, and acceleration values ​​collected by each acceleration sensor, as well as the sampling frequency. The sampling period is the reciprocal of the sampling frequency;

[0033] Step 3: Based on the data obtained in Step 2, calculate the maximum bump height of the vertical profile along the forward direction where each accelerometer is located. The formula is as follows: Where H is the maximum crowding height. The average acceleration when driving through the crowd, The average speed at which a vehicle passes through a congestion is given by denoted as T, and the time taken to pass through the congestion is given by denoted as T.

[0034] Step 4: According to the formula Find the crowd height at a given point, where h is the crowd height at that point. In the formula The acute angle between the vehicle and the ground. For instantaneous acceleration, Instantaneous vehicle speed Let be the sampling time interval; after substituting y, calculate h using definite integral.

[0035]

[0036]

[0037] Step 5: Based on h obtained in each sampling period, the relationship between the swarm height and time is obtained, and then the shape equation H(t) of the swarm along the forward direction is obtained. A total of 5 H(t) equations are obtained from 5 acceleration sensors.

[0038] Step Six: According to the formula The volume of a congestion in a single lane is obtained, where T is the time taken to pass through the congestion; then, according to the formula... The volume of a certain congestion packet is obtained, where m is the number of lanes;

[0039] Step 7: Compare the obtained maximum congestion height and congestion volume with preset thresholds. For example: Mild congestion: height less than 15mm, and processing range less than 2. Severe congestion: Height greater than 15mm, or processing area greater than 2 This allows us to determine the appropriate maintenance method.

[0040] Preferably, the acceleration sensor is a non-contact acceleration sensor, which is connected to the vehicle computer via a transmission line.

[0041] Preferably, the on-board computer binds the bulge volume, bulge height, and coordinates, and stores them in the on-board computer's database. When the detection vehicle passes the same location again, it automatically calculates the bulge volume and bulge height. The same road segment should be detected three times in a round trip. The range of the three detection results should not be greater than 10% of the average value. If the range is greater than 10% of the average value, the detection should be repeated.

[0042] Calculation of maximum crowding height: such as Figure 1 As shown, draw a vertical line at the maximum height of the swarm. Take a point on the lower part of this line below the ground. Connect this point to both the starting and ending points of the swarm, creating two line segments. The included angle between these two line segments is θ. Angle; the length of the line segment from this point to the start or end of the swarm is R. Here, it is assumed that the distance from this point to the start and end of the swarm is equal, thus obtaining formula (1) and formula (2):

[0043]

[0044] Substituting formula (1) into formula (2) yields: , will get Substitution The formula for the maximum crowding height is finally obtained. ,in For average acceleration, Let R be the average vehicle speed;

[0045] Micro-unit analysis:

[0046] like Figure 2 and Figure 3As shown, during the calculation, an arbitrary point is selected on the bulge packet, and this point is connected to the endpoint of the previous micro-unit to obtain a line segment. If this is the first calculation, the endpoint of the previous micro-unit is the point where the maximum bulge packet height is located. Then, a perpendicular line is drawn from the middle of this line segment, intersecting the bulge packet. The distance from the point where the perpendicular line intersects the bulge packet to the point where the perpendicular line intersects the line segment is x. A horizontal line is drawn at the selected point on the bulge packet, and the angle between the horizontal line and the aforementioned line segment is θ. horn, The angle is the acute angle between the vehicle and the ground; let y be the distance from the intersection of the perpendicular line and the road surface to the horizontal line, thus obtaining the following formula:

[0047]

[0048] Because in fact Therefore, substituting x into y yields... ;

[0049] We conducted an accuracy comparison between the detected and measured values ​​of bumps on a 2km test section of a road in Zoucheng City, Shandong Province. There were a total of 8 bumps, and the accuracy of height and area was greater than 97%, which meets the requirement of over 90% accuracy of automated detection and identification of road damage in the "Highway Technical Condition Assessment Standard". The area accuracy was slightly higher than the height accuracy. The detection data is as follows.

[0050]

[0051]

[0052] Taking the eighth crater as an example: average speed 40km / h (1)

[0054]

[0055] Input the above data into Excel to generate a curve showing the relationship between time and packet height, with time on the horizontal axis and packet height on the vertical axis.

[0056] Curve graph as Figure 4 As shown, the fitted shape equation along the forward direction is: R² represents the correlation coefficient, and the area is 4592. . (2)

[0058]

[0059] Curve graph as Figure 5 As shown, the shape equation is fitted along the forward direction: The area is 3886 . (3)

[0061]

[0062] Curve graph as Figure 6 As shown, the shape equation is fitted along the forward direction: The area is 3893 . (4)

[0064]

[0065] Curve graph as Figure 7 As shown, the shape equation is fitted along the forward direction: The area is 2148 . (5)

[0067]

[0068] Curve graph as Figure 8 As shown, the shape equation is fitted along the forward direction: The area is: 1483 .

[0069] In summary, the total volume of the packet is 16002 * 300 = 4800600. .

[0070] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention.

Claims

1. A method for inspecting bulges in asphalt pavement, characterized in that: Step 1: Drive the test vehicle to the starting point of the test section, turn on the on-board computer, and check whether the on-board computer, acceleration sensor and GPS are in good working order. The acceleration sensor is set on the chassis of the test vehicle along a linear array. Step Two: Start the vehicle and drive back and forth on the test section, one lane at a time. When encountering changes in vertical acceleration, the onboard computer automatically starts recording data, including vehicle speed, coordinates, time, and acceleration values ​​collected by each acceleration sensor, as well as the sampling frequency. The sampling period is the reciprocal of the sampling frequency; Step 3: Based on the data obtained in Step 2, calculate the maximum bump height of the vertical profile along the forward direction where each accelerometer is located. The formula is as follows: Where H is the maximum crowding height. The average acceleration when driving through the crowd, The average speed at which a vehicle passes through a congestion is given by denoted as T, and the time taken to pass through the congestion is given by denoted as T. Step 4: According to the formula Find the crowd height at a given point, where h is the crowd height at that point. In the formula The acute angle between the vehicle and the ground. For instantaneous acceleration, Instantaneous vehicle speed The sampling time interval; Step 5: Based on h obtained in each sampling period, obtain the relationship between the swarm height and time, and then obtain the shape equation H(t) of the swarm along the forward direction. The number of shape equations obtained is equal to the number of accelerometers. Step Six: According to the formula The volume of a congestion in a single lane is obtained, where c is the distance between two adjacent accelerometers, n is the number of accelerometers, and T is the time taken to pass through the congestion; then, according to the formula... The volume of a certain congestion packet is obtained, where m is the number of lanes; Step 7: Compare the obtained maximum packet height and packet volume with the preset thresholds.

2. The asphalt pavement bump inspection method as described in claim 1, characterized in that: The acceleration sensor is a non-contact acceleration sensor, which is connected to the vehicle's computer via a transmission line.

3. The method for inspecting asphalt pavement bumps as described in claim 1, characterized in that: The onboard computer binds the volume, height, and coordinates of the bulge to the data and stores it in the onboard computer's database. When the detection vehicle passes the same location again, it automatically calculates the volume and height of the bulge.

4. The method for inspecting asphalt pavement bumps as described in claim 1, characterized in that: The same road segment should be tested three times in both directions. The range of the three test results should not exceed 10% of the average value. If the range exceeds 10% of the average value, the test should be repeated.

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