Device for detecting void ratio of drainage asphalt pavement

Abstract

The utility model discloses a drainage asphalt pavement void ratio detection device which comprises a device shell, the device shell is of a barrel-shaped structure with an opening in the lower end, the opening lower end of the device shell is connected with the upper surface of a detected pavement in a sealed mode, and a supporting plate is arranged in the middle of the interior of the device shell. A fixing device is arranged between the center of the upper surface of the supporting plate and the top face in the device shell and is of a Chinese character'zhong '-shaped structure, and the center of the supporting plate and the top face of the device shell are each provided with an opening identical to the interior of the fixing device, so that gas at the lower end in the device shell penetrates through the interior of the fixing device and is exhausted from the upper end. The method does not need to perform coring excavation on the detected pavement, does not damage the pavement structure, has no influence on the quality of the detected pavement, can greatly improve the detection speed of the void ratio of the drainage asphalt pavement, and provides lossless, accurate and efficient data support for pavement detection maintenance or repair decision.

Description

Technical Field

[0001] This utility model relates to the field of asphalt pavement drainage testing technology, specifically a device for testing the porosity of drainage asphalt pavement. Background Technology

[0002] OGFC (Open-Graded Friction Course) is a special type of drainage asphalt concrete pavement structure characterized by the use of larger-diameter aggregates in the surface layer to increase drainage performance and reduce road noise. Porosity testing is one of the important indicators for evaluating the quality of OGFC pavements. Porosity refers to the proportion of voids between asphalt concrete aggregates in the total volume of the pavement. By testing the porosity, the compactness and durability of the pavement can be assessed, and it can help determine whether maintenance or repair work is needed.

[0003] Currently, methods for detecting the porosity of pavement layers mainly fall into two categories: density-based and physical index-based. Density-based methods include core drilling, nuclear density metering, and nuclear-free density metering, which determine porosity by measuring pavement density or density-related indicators. These methods are highly accurate, but the need for core excavation and laboratory testing leads to low work efficiency. Physical index-based methods mainly include the permeability coefficient method, which indirectly determines porosity by measuring relevant pavement physical indicators. However, the permeability coefficient method is time-consuming and cumbersome to operate. To further rapidly, comprehensively, and accurately evaluate the quality of OGFC pavements, it is necessary to develop a permeable asphalt pavement porosity detection device. Utility Model Content

[0004] The technical problem to be solved by this utility model is to overcome the existing defects and provide a device for detecting the void ratio of permeable asphalt pavement. This device does not require core excavation of the pavement to be tested, does not damage the pavement structure, and has no impact on the quality of the pavement. It can greatly improve the detection speed of the void ratio of permeable asphalt pavement and provide non-destructive, accurate and efficient data support for pavement inspection, maintenance or repair decisions. It can effectively solve the problems in the background art.

[0005] To achieve the above objectives, this utility model provides the following technical solution: a device for detecting the porosity of a drainage asphalt pavement, comprising a device housing, the device housing being a barrel-shaped structure with an open bottom, the lower end of the opening of the device housing being sealed to the upper surface of the pavement to be tested, a support plate being provided in the middle of the interior of the device housing, a fixing device being provided between the center of the upper surface of the support plate and the top surface of the interior of the device housing, the fixing device being a U-shaped structure, the center of the support plate and the top surface of the device housing respectively being provided with the same opening as the interior of the fixing device, thereby allowing the gas at the lower end of the interior of the device housing to pass through the interior of the fixing device and be discharged from the upper end, an axial flow fan for blowing air to the outside of the device housing being provided at the upper end of the interior of the fixing device, a wind speed sensor for detecting the speed of gas being discharged from the device housing being fixed in the middle of the interior of the fixing device by a bracket, a signal sensor for detecting wind pressure and temperature being provided at the upper opening of the device housing, and a display and control terminal for controlling the device being provided on the upper surface of the device housing, while a battery for providing power to the device is provided on the upper surface of the support plate;

[0006] Furthermore, the display and control terminal consists of a coordinate positioning chip, a control processing unit, a 4G communication module, an LCD module, and a storage module. The LCD module enables human-machine interaction, transmitting control signals to the control processing unit to allow the operator to control the detection equipment. When the operator selects to start the detection, the LCD module sends a start signal to the control processing unit. The control processing unit collects and processes this signal, then sends a start signal to the axial flow fan to control its operation. The control processing unit receives wind speed signals from the signal sensor and wind speed sensor, determines the operating time of the axial flow fan through an algorithm, and uses a fixing device... Once the air velocity in the channel reaches equilibrium, a stop signal is sent to the axial flow fan. Simultaneously, the control processing unit calculates the road surface porosity by analyzing the wind speed, wind pressure, and temperature signals at equilibrium. It also collects and processes the coordinate information sent by the coordinate positioning chip and sends it to the 4G communication module. The 4G communication module processes the signal and transmits it to the client terminal via the 4G wireless network for viewing. The storage module stores the road surface porosity data, allowing users to easily view historical data through the LCD module. Historical data can also be exported via the USB interface for quick and easy downloading to external storage.

[0007] Furthermore, a rubber sealing ring is provided on the lower outer side of the device housing, and the lower end of the cross-section of the rubber sealing ring has a wavy structure.

[0008] Furthermore, a handle is bolted to the upper surface of the device housing, and the handle is an inverted U-shaped structure.

[0009] Furthermore, the wind speed sensor includes a connecting shell connected to a fixing device via a mounting bracket. The connecting shell has a rotating shaft rotatably connected in the middle. The upper end of the rotating shaft is provided with a rotating outer shell. Blades are evenly distributed on the outer side of the rotating outer shell. A detection protrusion is provided in the middle of the outer side of the rotating shaft. The connecting shell has a detection element for detecting the detection protrusion inside.

[0010] Furthermore, the signal sensors include a wind pressure sensor and a temperature sensor. The wind pressure sensor and temperature sensor detect wind pressure and temperature, and transmit the wind pressure signal and temperature signal to the display and control terminal. The wind speed sensor detects wind speed information and transmits the wind speed signal to the display and control terminal. The display and control terminal processes and calculates the detected information, and the calculation method is as follows:

[0011] When the exhaust fan starts working:

[0012] When this condition is met, V i =V n ,

[0013] At this point, the porosity is:

[0014]

[0015] Where V n In this context, 'n' represents the detection sampling sequence, which increments by 1 every 500ms, and V... i The signal represents the air speed in equilibrium, with units of m / s. k3, k2, and k1 represent the regression coefficients for air speeds on asphalt pavements with different drainage properties. P represents the air pressure signal in equilibrium, with units of Pa and kJ. P k P1 and k P0 , respectively, represent the regression coefficients of air pressure for different types of drainage asphalt pavements, T represents the equilibrium air temperature signal in °C, k1 represents the regression coefficient of air temperature, and ε represents the porosity of the drainage asphalt pavement in %.

[0016] Compared with the prior art, the beneficial effects of this utility model are as follows: This drainage asphalt pavement porosity detection device has the following advantages:

[0017] 1. The drainage asphalt pavement porosity testing device of this utility model does not require core excavation of the test pavement, does not damage the pavement structure, and has no impact on the quality of the test pavement.

[0018] 2. This utility model can greatly improve the detection speed of porosity of drainage asphalt pavement, providing non-destructive, accurate and efficient data support for pavement inspection, maintenance or repair decisions.

[0019] 3. This utility model has a simple structure. The handle makes it easier to pick up the device. The wavy rubber sealing ring on the lower surface forms multiple seals between the lower surface of the device shell and the road surface being tested, thereby improving the sealing effect between the device shell and the road surface and making the test more accurate.

[0020] 3. When the axial flow fan is working, the airflow at the lower end of the device housing is drawn out. When the airflow passes through the wind speed sensor, the airflow drives the blades and the rotating housing to rotate. The rotating housing drives the rotating shaft to rotate, and the rotating shaft drives the detection protrusion to rotate. The detection protrusion is detected by the detection element, thereby detecting the wind speed through which the airflow passes. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of this utility model;

[0022] Figure 2 This is a schematic diagram of the front structure of this utility model;

[0023] Figure 3 This is a schematic cross-sectional view of the present invention.

[0024] Figure 4 This is a schematic diagram of the wind speed sensor structure of this utility model;

[0025] Figure 5 This is a schematic diagram of the rubber sealing ring structure of this utility model;

[0026] Figure 6 This is a schematic diagram of the airflow direction structure of this utility model;

[0027] Figure 7 This is a schematic diagram of the working process structure of the display and control terminal of this utility model;

[0028] Figure 8 This is a schematic diagram of the signal detection process structure of the detection device of this utility model;

[0029] Figure 9 This is a schematic diagram of the detection process structure of this utility model.

[0030] In the diagram: 1. Detected road surface, 2. Rubber sealing ring, 3. Device housing, 4. Battery, 5. Wind speed sensor, 51. Blade, 52. Connecting shell, 53. Rotating shell, 54. Rotating shaft, 55. Detection protrusion, 56. Detection component, 6. Axial flow fan, 7. Signal sensor, 8. Handle, 9. Fixing device, 10. Support plate, 11. Display and control terminal. Detailed Implementation

[0031] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0032] Please see Figure 1-9 This utility model provides a technical solution: a device for detecting the porosity of a drainage asphalt pavement, including a device housing 3, which is a barrel-shaped structure with an open bottom. The lower end of the opening of the device housing 3 is sealed to the upper surface of the pavement 1 being tested. A support plate 10 is provided in the middle of the interior of the device housing 3. A fixing device 9 is provided between the center of the upper surface of the support plate 10 and the top surface of the interior of the device housing 3. The fixing device 9 is a U-shaped structure. The center of the support plate 10 and the top surface of the device housing 3 are respectively provided with the same opening as the interior of the fixing device 9, thereby allowing the gas at the lower end of the interior of the device housing 3 to pass through the interior of the fixing device 9 and be discharged from the upper end. An axial flow fan 6 is provided at the upper end of the interior of the fixing device 9 to blow air to the outside of the device housing 3. A wind speed sensor 5 for detecting the speed of gas discharge from the device housing 3 is fixed in the middle of the interior of the fixing device 9 by a bracket. A signal sensor 7 for detecting wind pressure and temperature is provided at the upper opening of the device housing 3. A display and control terminal 11 for controlling the device is provided on the upper surface of the device housing 3, and a battery 4 for providing power to the device is provided on the upper surface of the support plate 10.

[0033] The display and control terminal 11 consists of a coordinate positioning chip, a control processing unit, a 4G communication module, an LCD module, and a storage module. The LCD module enables human-machine interaction, transmitting control signals to the control processing unit to allow the operator to control the detection equipment. When the operator selects to start the detection, the LCD module sends a start signal to the control processing unit. The control processing unit collects and processes this signal, then sends a start signal to the axial flow fan 6 to control its operation. The control processing unit receives wind speed signals from the signal sensor 7 and the wind speed sensor 5, determines the operating time of the axial flow fan 6 through an algorithm, and then uses the fixing device 9 to... Once the air velocity in the channel reaches equilibrium, a stop signal is sent to the axial flow fan 6. Simultaneously, the control processing unit calculates the road surface porosity by analyzing the wind speed, wind pressure, and temperature signals at equilibrium. It also collects and processes the coordinate information sent by the coordinate positioning chip and sends it to the 4G communication module. The 4G communication module processes the signal and sends it to the client terminal via the 4G wireless network for viewing. The storage module stores the road surface porosity data, allowing users to easily view historical data through the LCD module. Historical data can also be exported via the USB interface, allowing for quick and easy downloading of data to external storage.

[0034] A rubber sealing ring 2 is provided on the lower outer side of the device housing 3. The lower end of the cross section of the rubber sealing ring 2 has a wavy structure. The wavy structure of the rubber sealing ring 2 on the lower surface makes multiple seals between the lower surface of the device housing 3 and the road surface 1 to be tested, thereby making the connection and sealing effect between the device housing 3 and the road surface 1 better.

[0035] A handle 8 is bolted to the upper surface of the device housing 3. The handle 8 is an inverted U-shaped structure, which makes it easier to pick up the device.

[0036] The wind speed sensor 5 includes a connecting shell 52 connected to a fixing device 9 via a mounting bracket. A rotating shaft 54 ​​is rotatably connected inside the connecting shell 52. A rotating outer shell 53 is located at the upper end of the rotating shaft 54. Blades 51 are evenly distributed on the outer side of the rotating outer shell 53. A detection protrusion 55 is located in the middle of the outer side of the rotating shaft 54. A detection element 56 for detecting the detection protrusion 55 is located inside the connecting shell 52. When the axial flow fan 6 operates, it draws airflow from the lower end of the device's outer shell 3. When the airflow passes through the wind speed sensor 5, it drives the blades 51 and the rotating outer shell 53 to rotate. The rotating outer shell 53 drives the rotating shaft 54 ​​to rotate, which in turn drives the detection protrusion 55 to rotate. The detection element 56 detects the detection protrusion 55, thereby detecting the wind speed through which the airflow passes. This device for detecting the porosity of permeable asphalt pavement eliminates the need for core excavation of the pavement, does not damage the pavement structure, and has no impact on the quality of the pavement. It significantly improves the detection speed of the porosity of permeable asphalt pavement, providing non-destructive, accurate, and efficient data support for pavement inspection, maintenance, or repair decisions.

[0037] Signal sensor 7 includes a wind pressure sensor and a temperature sensor, which detect wind pressure and temperature, and transmit the wind pressure signal and temperature signal to the display and control terminal 11. Wind speed sensor 5 detects wind speed information and transmits the wind speed signal to the display and control terminal 11.

[0038] The device is made easier to pick up by using the handle 8. The device is then placed on the surface of the test road 1 to be tested. The rubber sealing ring 2 with its wavy structure on the lower surface forms multiple seals between the lower surface of the device housing 3 and the test road 1, thus improving the sealing effect between the device housing 3 and the test road 1. Then, the axial flow fan 6 works to draw the gas at the lower end of the device housing 3 into a negative pressure, while the external gas enters the lower end of the device housing 3 through the test road 1. When the airflow passes through the wind speed sensor 5, the airflow drives the blades 51 and the rotating housing 53 to rotate. The rotating housing 53 drives the rotating shaft 54 ​​to rotate, and the rotating shaft 54 ​​drives the detection protrusion 55 to rotate. The detection element 56 detects the detection protrusion 55 to detect the wind speed of the airflow. The wind pressure and temperature are detected by the wind pressure sensor and temperature sensor on the signal sensor 7. The wind pressure signal and temperature signal are then transmitted to the display and control terminal 11. The wind speed sensor 5 detects the wind speed information and transmits the wind speed signal to the display and control terminal 11.

[0039] The LCD module on the display and control terminal 11 sends a start signal to the control processing unit. The control processing unit collects and processes the signal, and then sends a start signal to the axial flow fan 6 to control the axial flow fan 6 to work. The control processing unit receives wind speed signals from the signal sensor 7 and the wind speed sensor 5. It determines through an algorithm that when the axial flow fan 6 is working, the air speed in the channel of the fixing device 9 reaches a balanced state, and then sends a stop signal to the axial flow fan 6. At the same time, the control processing unit calculates the road surface porosity by analyzing the wind speed, wind pressure, and temperature signals in the balanced state. It also collects and processes the coordinate information sent by the coordinate positioning chip and sends it to the 4G communication module. The 4G communication module processes the signal and sends it to the client terminal for viewing via the 4G wireless network. The storage module stores the road surface porosity data, allowing users to view historical data through the LCD module. Historical data can also be exported via the USB transmission interface, making it easy and quick to download data to external storage.

[0040] The calculation formula for display and control terminal 11 is as follows:

[0041] When the exhaust fan starts working;

[0042] When this condition is true, V = Vn.

[0043] At this point, the porosity is:

[0044]

[0045] Where V n V represents the wind speed signal from the sensor at the start of detection. n In this context, 'n' represents the detection sampling sequence, which increments by 1 every 500ms; 'V' represents the equilibrium air velocity signal in m / s; 'P' represents the equilibrium air pressure signal in Pa; 'T' represents the equilibrium air temperature signal in ℃; and 'ε' represents the porosity in %.

[0046] When processing wind pressure, temperature, and wind speed signals, the validity of the output data from each sensor cannot be determined. Therefore, the output data must be judged before fusion calculation. The authenticity of the data is judged based on the relationship between the measurement data of each sensor and by making full use of prior knowledge.

[0047] Temperature is measured using N sensors, where X1, X2…XN represent the physical values ​​output by the N sensors, and p(x1), p(x2),…p(xN) represent the probability density functions of X1, X2…XN, all following a normal distribution; x1, x2…xN represent samples of X1, X2…XN; then the confidence distance is...

[0048]

[0049] Equation {1} represents the confidence distance of a pair, and similarly, Equation {2} represents the confidence distance of a pair; where

[0050]

[0051] According to the above formula, dij reflects the degree to which the data output by sensor i supports the data output by sensor j; similarly, the confidence distance matrix can be calculated using this method as follows:

[0052]

[0053] After obtaining the confidence distance matrix, a relation matrix needs to be established to determine the support level and validity of the sensor output data. Combining the concept of membership degree in fuzzy mathematics, thresholds δ1 and δ2 are introduced. When the confidence distance meets the requirements, it indicates that the output value of temperature sensor i supports the output value of temperature sensor j; otherwise, it indicates that the output value of temperature sensor i does not support the output value of temperature sensor j, as shown in equation (5).

[0054]

[0055] Since all N sensors measure the same temperature, theoretically the values ​​should be the same. However, due to sensor accuracy and errors, the measured values ​​will have some differences. The higher the degree of support among the N sensors, the closer the sensor is to the true value. Therefore, values ​​with a high degree of support are selected for fusion calculation to further improve accuracy.

[0056] Obtain the relation matrix ψ

[0057]

[0058] Due to the continuous changes in operating conditions and the variations in various parameters within the sensor itself, the uncertainty of the measured temperature value increases over time. Therefore, Bayesian estimation fusion needs to describe the changes in this uncertain dynamic. The m valid data points selected from the relation matrix are represented as (x1, x2, x3…xm), and the conditional probability density function of the measured parameter can be derived from the following formula:

[0059]

[0060] In the formula: μ is the measured parameter, which follows a normal distribution N(μ0, σ0), and Xi also follows a normal distribution N(μ, σk). Therefore, we can obtain...

[0061]

[0062] In the formula:

[0063]

[0064] Substituting equations (10) and (11) into equation (9), it is easy to obtain p(μ|x1, x2, x3...x m It also follows a normal distribution, assumed to follow N(μN, σ). N )Right now:

[0065]

[0066] Combining equations (9) and (11), we can obtain the following result:

[0067]

[0068] The above-described application of the Bayesian estimation algorithm is used to diagnose faults in the tested sensor. The specific steps can be summarized as follows:

[0069] First, acquire the values ​​of each sensor; second, perform Bayesian estimation and data fusion on the data from each sensor; third, set the difference between the sensor under test and the fusion result; fourth, calculate the difference between the sensor under test and the fusion result, and consider it a fault if the difference exceeds the value; based on the above steps, faults can be determined for each sensor under test.

[0070] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention.

Claims

1. A device for detecting the porosity of drainage asphalt pavement, comprising a housing (3), characterized in that: The outer shell (3) of the device is a barrel-shaped structure with an opening at the bottom. The lower end of the opening of the outer shell (3) is sealed to the upper surface of the road surface (1) being tested. A support plate (10) is provided in the middle of the interior of the outer shell (3). A fixing device (9) is provided between the center of the upper surface of the support plate (10) and the top surface of the interior of the outer shell (3). The fixing device (9) is a U-shaped structure. The center of the support plate (10) and the top surface of the outer shell (3) are respectively provided with the same opening as the interior of the fixing device (9), thereby allowing the gas at the lower end of the interior of the outer shell (3) to pass through. The gas is discharged from the top inside the fixed device (9). An axial flow fan (6) is installed at the top inside the fixed device (9) to blow air to the outside of the device housing (3). A wind speed sensor (5) is fixed in the middle inside the fixed device (9) by a bracket to detect the speed of the gas being discharged from the device housing (3). A signal sensor (7) for detecting wind pressure and temperature is installed at the opening at the top of the device housing (3). A display and control terminal (11) for controlling the device is installed on the upper surface of the device housing (3). A battery (4) for providing power to the device is installed on the upper surface of the support plate (10).

2. The device for detecting the porosity of permeable asphalt pavement according to claim 1, characterized in that: The display and control terminal (11) consists of a coordinate positioning chip, a control processing unit, a 4G communication module, an LCD module, and a storage module. The LCD module enables human-machine interaction and transmits control signals to the control processing unit, enabling the operator to control the detection equipment. When the operator selects to start the detection, the LCD module sends a start signal to the control processing unit. The control processing unit collects and processes the signal, and then sends a start signal to the axial flow fan (6) to control the axial flow fan (6) to work. The control processing unit receives the wind speed signals sent by the signal sensor (7) and the wind speed sensor (5), determines the working time of the axial flow fan (6) through an algorithm, and then uses a fixed... When the air velocity in the channel of the positioning device (9) reaches a balanced state, a stop signal is sent to the axial flow fan (6). At the same time, the control processing unit calculates the road surface porosity by analyzing the wind speed signal, wind pressure signal, and temperature signal under the balanced state. It also collects and processes the coordinate information sent by the coordinate positioning chip and sends it to the 4G communication module. The 4G communication module processes the signal and sends it to the client terminal for viewing via the 4G wireless network. The storage module stores the road surface porosity data, which is convenient for users to view historical data through the LCD module. It can also export historical data through the USB transmission interface, making it easy and quick to download the data to the external storage.

3. The device for detecting the porosity of permeable asphalt pavement according to claim 1, characterized in that: The lower outer side of the outer casing (3) of the device is provided with a rubber sealing ring (2), and the lower end of the cross section of the rubber sealing ring (2) has a wavy structure.

4. The device for detecting the porosity of permeable asphalt pavement according to claim 1, characterized in that: The upper surface of the device housing (3) is bolted with a handle (8), which is an inverted U-shaped structure.

5. The device for detecting the porosity of permeable asphalt pavement according to claim 1, characterized in that: The wind speed sensor (5) includes a connecting shell (52) connected to a fixing device (9) via a mounting bracket. The connecting shell (52) has a rotating shaft (54) rotatably connected in the middle. The upper end of the rotating shaft (54) is provided with a rotating outer shell (53). The outer side of the rotating outer shell (53) is uniformly provided with blades (51). The outer side of the rotating shaft (54) is provided with a detection protrusion (55). The connecting shell (52) has a detection element (56) for detecting the detection protrusion (55).

6. The device for detecting the porosity of permeable asphalt pavement according to claim 1, characterized in that: The signal sensor (7) includes a wind pressure sensor and a temperature sensor. The wind pressure sensor and temperature sensor detect the wind pressure and temperature, and transmit the wind pressure signal and temperature signal to the display and control terminal (11). The wind speed sensor (5) detects the wind speed information and transmits the wind speed signal to the display and control terminal (11). The display and control terminal (11) processes and calculates the detected information. The calculation method is as follows: When the exhaust fan starts working: When the condition is met, V i =V n , At this point, the porosity is: Where V n In this context, 'n' represents the detection sampling sequence, which increments by 1 every 500ms, and V... i The signal represents the air speed in equilibrium, with units of m / s. k3, k2, and k1 represent the regression coefficients for air speeds on asphalt pavements with different drainage properties. P represents the air pressure signal in equilibrium, with units of Pa and kJ. P k P1 and k P0 , respectively, represent the regression coefficients of air pressure for different types of drainage asphalt pavements, T represents the equilibrium air temperature signal in °C, k1 represents the regression coefficient of air temperature, and ε represents the porosity of the drainage asphalt pavement in %.

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