A method and apparatus for detecting the thickness of asphalt paving

Abstract

The application relates to a bitumen paving thickness detection method and device, which comprises the following steps: obtaining initial equivalent velocities of signals from a sending end to a top surface of a bitumen layer and a bottom surface of the bitumen layer respectively through CMP velocity inversion and performing environment correction to obtain corrected equivalent velocities of the signals in the bitumen layer; calculating actual equivalent dielectric constants of the bitumen layer according to volume fractions of each component of the bitumen layer and calculating a priori equivalent velocities of the signals in the bitumen layer; performing weighted fusion on the corrected equivalent velocities of the signals in the bitumen layer and the a priori equivalent velocities to obtain final equivalent velocities of the signals in the bitumen layer; obtaining round-trip durations of the signals from the sending end to a bottom surface of an ice layer and from the sending end to the bottom surface of the bitumen layer to calculate a round-trip duration of the signals in the bitumen layer; and calculating an actual thickness of the bitumen layer.

Description

Technical Field

[0001] This invention relates to the field of asphalt thickness detection technology, specifically to a method and equipment for detecting asphalt paving thickness. Background Technology

[0002] The accuracy of existing asphalt paving thickness detection based on vehicle-mounted GPR is easily affected by multiple factors in low-temperature permafrost environments: First, frost, thin ice, or localized icing on the road surface leads to the superposition of multiple interfaces of air / ice / asphalt, making it difficult to identify the echo from the transmitting end to the top surface of the asphalt layer and causing deviations in the round-trip time; Second, low temperature and cold and humid conditions cause changes in the actual equivalent dielectric constant of the asphalt layer, and the mismatch between the fixed dielectric constant and the signal velocity assumption leads to distortion in the estimation of signal propagation speed. Summary of the Invention

[0003] The purpose of this invention is to provide a method and equipment for detecting the thickness of asphalt paving, which can significantly improve the accuracy and stability of measuring the actual thickness of asphalt layers in low-temperature frozen soil environments, reduce the error caused by frost interference, and achieve continuous and reliable thickness detection results.

[0004] To achieve the above objectives, according to a first aspect of the present invention, a method for detecting asphalt paving thickness is provided, comprising the following steps:

[0005] Sending and receiving electromagnetic wave signals to and from the asphalt pavement;

[0006] The initial equivalent velocities of the signal from the transmitter to the top and bottom surfaces of the asphalt layer are obtained through CMP velocity inversion, and then environmental corrections are applied to obtain the corrected equivalent velocities of the signal within the asphalt layer. ;

[0007] The actual equivalent dielectric constant of the asphalt layer is calculated based on the volume fraction of each component. And based on the actual equivalent dielectric constant of the asphalt layer Calculate the a priori equivalent velocity of the signal in the asphalt layer ;

[0008] Corrected equivalent velocity of the signal in the asphalt layer and a priori equivalent speed Weighted fusion is performed to obtain the final equivalent velocity of the signal in the asphalt layer. ;

[0009] The round-trip time of the signal from the transmitting end to the bottom of the ice layer and from the transmitting end to the bottom of the asphalt layer is obtained in order to calculate the round-trip time of the signal in the asphalt layer. ;

[0010] Based on the final equivalent velocity of the signal in the asphalt layer and the round-trip time of the signal in the asphalt layer Calculate the actual thickness h of the asphalt layer.

[0011] Optionally, the initial equivalent velocity of the signal from the transmitting end to the top and bottom surfaces of the asphalt layer is obtained through CMP velocity inversion, and then environmental correction is applied to obtain the corrected equivalent velocity of the signal in the asphalt layer. It includes the following steps:

[0012] The initial equivalent velocity of the signal from the transmitting end to the top surface of the asphalt layer was obtained by scanning the CMP velocity spectrum, correcting for normal time difference, and superimposing scores. Round trip time And the initial equivalent velocity of the signal from the transmitting end to the bottom of the asphalt layer. Round trip time ;

[0013] Asphalt pavement temperature and ambient relative humidity are obtained to calculate environmental weights. ;

[0014] According to environmental weight The initial equivalent velocities of the signal from the transmitting end to the top and bottom surfaces of the asphalt layer are corrected to obtain the corrected equivalent velocities of the signal from the transmitting end to the top and bottom surfaces of the asphalt layer, respectively. and ;

[0015] Based on the corrected equivalent velocity from the transmitting end to the top and bottom surfaces of the asphalt layer respectively. and The corrected equivalent velocity of the signal in the asphalt layer was calculated. .

[0016] Optionally, the signal is corrected for the equivalent velocity in the asphalt layer. It can be obtained through the following formula:

[0017] .

[0018] Optionally, the environmental weights It can be obtained through the following formula:

[0019] ;

[0020] Where T is the asphalt pavement temperature and RH is the ambient relative humidity. Temperature scale;

[0021] The corrected equivalent speeds of the signal from the transmitting end to the top and bottom surfaces of the asphalt layer, respectively. and It can be obtained through the following formula:

[0022] ;

[0023] in, The corrected equivalent speed of the signal from the transmitting end to the target interface. This is the initial equivalent velocity of the signal from the transmitting end to the target interface.

[0024] Optionally, the prior equivalent velocity of the signal in the asphalt layer It can be obtained through the following formula:

[0025] ;

[0026] ;

[0027] Where c is the speed of light. , , , These represent the volume fractions of aggregate, air, ice, and unfrozen water in the asphalt layer, respectively. , , , , respectively, are the dielectric constants of aggregate, air, ice, and unfrozen water in the asphalt layer.

[0028] Optionally, the volume fractions of aggregate, air, ice, and unfrozen water in the asphalt layer are obtained using the following formula:

[0029] ;

[0030] ;

[0031] ;

[0032] ;

[0033] in, S represents the porosity of the asphalt layer, and S represents the pore water saturation. This represents the volume fraction of total water in the asphalt layer. , and These are the calibration constants for the project.

[0034] Optionally, the final equivalent velocity of the signal in the asphalt layer It can be obtained through the following formula:

[0035] ;

[0036] in, The fusion weights are the corrected equivalent velocities of the signal in the asphalt layer. The fusion weight is the prior equivalent velocity of the signal in the asphalt layer.

[0037] Optionally, the actual thickness h of the asphalt layer is obtained by the following formula;

[0038] .

[0039] According to a second aspect of the present invention, an asphalt paving thickness detection device is provided for performing the asphalt paving thickness detection method, the detection device comprising:

[0040] Mobile mechanism;

[0041] A multi-offset GPR array, positioned below the moving mechanism, is used to transmit and receive electromagnetic wave signals to the asphalt pavement;

[0042] A laser altimeter, arranged in parallel with the multi-offset GPR array, is used for zero-point compensation of time variations in ground elevation.

[0043] A temperature and humidity sensor is installed at the front of the moving mechanism and close to the asphalt road surface to detect the temperature of the asphalt road surface and the relative humidity of the environment.

[0044] Differential GPS and IMU are mounted on top of the mobile mechanism for position and attitude registration;

[0045] The control system is located within the moving mechanism and is electrically connected to the multi-offset GPR array, the laser altimeter, the temperature and humidity sensor, and the differential GPS and IMU, respectively.

[0046] The beneficial effects of this invention are as follows: by using CMP velocity inversion and combining it with environmental correction, the adaptability of the corrected equivalent velocity of the signal in the asphalt layer to low temperature and cold and humid conditions is improved. The actual equivalent dielectric constant is calculated based on the volume fraction of each component in the asphalt layer, and the a priori equivalent velocity of the signal in the asphalt layer is obtained. Then, the corrected equivalent velocity and the a priori equivalent velocity are weighted and fused to obtain a more accurate final equivalent velocity of the signal in the asphalt layer. At the same time, the round-trip time of the signal from the transmitting end to the bottom of the ice layer and to the bottom of the asphalt layer is obtained to calculate the round-trip time of the signal in the asphalt layer, thereby reducing the error transmission caused by the influence of ice and frost on the asphalt surface and improving the overall accuracy of measuring the actual thickness of the asphalt layer in low temperature and frozen soil environment.

[0047] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, the preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0048] Figure 1This is a schematic flowchart illustrating an embodiment of an asphalt paving thickness detection method according to the present invention;

[0049] Figure 2 for Figure 1 A schematic flowchart of step S20. Detailed Implementation

[0050] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0051] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0052] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances. Furthermore, the technical features involved in the different embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0053] Please see Figure 1 A preferred embodiment of this application illustrates a method for detecting asphalt paving thickness, comprising the following steps:

[0054] Step S10: Send and receive electromagnetic wave signals to and from the asphalt pavement;

[0055] Step S20: Obtain the initial equivalent velocity of the signal from the transmitting end to the top and bottom surfaces of the asphalt layer through CMP velocity inversion, and perform environmental correction to obtain the corrected equivalent velocity of the signal in the asphalt layer. ;

[0056] Step S30: Calculate the actual equivalent dielectric constant of the asphalt layer based on the volume fraction of each component. And based on the actual equivalent dielectric constant of the asphalt layer Calculate the a priori equivalent velocity of the signal in the asphalt layer ;

[0057] Step S40: Correct the equivalent velocity of the signal in the asphalt layer and a priori equivalent speed Weighted fusion is performed to obtain the final equivalent velocity of the signal in the asphalt layer. ;

[0058] Step S50: Obtain the round-trip time of the signal from the transmitting end to the bottom of the ice layer and from the transmitting end to the bottom of the asphalt layer, so as to calculate the round-trip time of the signal in the asphalt layer. ;

[0059] Step S60: Based on the final equivalent velocity of the signal in the asphalt layer and the round-trip time of the signal in the asphalt layer Calculate the actual thickness h of the asphalt layer.

[0060] According to the scheme of the present invention, the adaptability of the corrected equivalent velocity of the signal in the asphalt layer to low temperature and cold and humid conditions is improved by CMP velocity inversion and environmental correction. The actual equivalent dielectric constant is calculated based on the volume fraction of each component in the asphalt layer to obtain the a priori equivalent velocity of the signal in the asphalt layer. Then, the corrected equivalent velocity and the a priori equivalent velocity are weighted and fused to obtain a more accurate final equivalent velocity of the signal in the asphalt layer. At the same time, the round-trip time of the signal from the transmitting end to the bottom of the ice layer and to the bottom of the asphalt layer is obtained to calculate the round-trip time of the signal in the asphalt layer, thereby reducing the error propagation caused by the influence of ice and frost on the asphalt surface and improving the overall accuracy of measuring the actual thickness of the asphalt layer in low temperature and frozen soil environment.

[0061] The following detailed description uses specific examples:

[0062] Specifically, please see Figure 2 Step S20 includes the following steps:

[0063] Step S201: By scanning the CMP velocity spectrum, correcting for normal time difference, and performing superposition scoring, the initial equivalent velocity of the signal from the transmitting end to the top surface of the asphalt layer is obtained. Round trip time And the initial equivalent velocity of the signal from the transmitting end to the bottom of the asphalt layer. Round trip time ;

[0064] Step S202: Obtain asphalt pavement temperature and ambient relative humidity to calculate environmental weights. ;

[0065] Step S203: Based on environmental weights The initial equivalent velocities of the signal from the transmitting end to the top and bottom surfaces of the asphalt layer are corrected to obtain the corrected equivalent velocities of the signal from the transmitting end to the top and bottom surfaces of the asphalt layer, respectively. and ;

[0066] Step S204: Based on the corrected equivalent velocity from the transmitting end to the top and bottom surfaces of the asphalt layer respectively. and The corrected equivalent velocity of the signal in the asphalt layer was calculated. .

[0067] In step S201, after the electromagnetic wave signal is transmitted and received, the multi-offset channels are first organized into a CMP gather according to their common midpoint. Then, a CMP velocity spectrum scan is performed. A set of candidate velocities is selected, and normal time difference correction is performed on each candidate velocity to straighten each offset channel. The straightened offset channels are then superimposed and scored to form a velocity-time score map. Within a pre-defined time window at the top surface of the asphalt layer, the score peak point is found, and its time coordinate is the round-trip time of the signal from the transmitting end to the top surface of the asphalt layer. Its velocity coordinates represent the initial equivalent velocity of the signal from the transmitting end to the top surface of the asphalt layer. Within the time window at the bottom of the asphalt layer, the round-trip time of the signal from the transmitting end to the bottom of the asphalt layer is obtained using the same method. The initial equivalent velocity of the signal from the transmitting end to the bottom of the asphalt layer CMP speed inversion is a conventional technique and will not be described in detail here.

[0068] Specifically, this environmental weight It can be obtained through the following formula:

[0069] (1);

[0070] Where T is the asphalt pavement temperature and RH is the ambient relative humidity. It is a temperature scale.

[0071] This formula describes the degree of disturbance from cold and humid environments by multiplying the temperature (T) and humidity (RH) below zero degrees Celsius, and normalizes it using a temperature scale. When T is greater than or equal to 0 degrees Celsius, the environmental weight is set to... The value is 0, in which case no additional correction is applied; the environmental weight increases as the environment becomes colder and more humid. In this embodiment, the temperature scale is set to 10°C.

[0072] The corrected equivalent velocity of the signal from the transmitting end to the top and bottom surfaces of the asphalt layer, respectively. and It can be obtained through the following formula:

[0073] (2);

[0074] in, The corrected equivalent speed of the signal from the transmitting end to the target interface. This represents the initial equivalent velocity of the signal from the transmitting end to the target interface. This formula linearly transforms the environmental weight into an attenuation coefficient for the initial equivalent velocity. As the environmental weight increases, it proportionally suppresses excessively fast velocity estimation caused by frost or unfrozen water, thereby reducing the amplification of errors in the calculation of asphalt layer thickness.

[0075] Furthermore, when the proportion of near-surface frost or unfrozen water changes, the measured round-trip time of the far offset is... It will deviate from the Round-trip time of the signal from the transmitting end to the target interface with zero offset The established theoretical hyperbola leads to systematic bias. Therefore, to suppress the systematic influence of travel-time curvature mismatch at large offsets in the solution of asphalt layer thickness under low-temperature frozen soil conditions, it is necessary to correct the equivalent velocity... The deflection curvature index C is introduced as a curvature correction factor. At this point, the equivalent velocity is corrected. It can be obtained through the following formula:

[0076] (3);

[0077] The offset curvature index C is obtained by the following formula:

[0078] (4);

[0079] Where far is the set of far offset channels selected from large to small offset distance. Usually, 2-3 channels with good signal-to-noise ratio at large offset distances are selected as the set of far offset channels. The offset of the i-th far offset track in the set is obtained by installation and calibration of the multi-offset GPR array; The measured round-trip time of the i-th far offset track is obtained by automatically picking it up within the time window of the target interface; This represents the number of far-off track lines. It should be noted that when calculating the far-off curvature index C from the transmitting end to the top surface of the asphalt layer, Pick , Pick When calculating the far-off curvature index C of the signal from the transmitting end to the bottom surface of the asphalt layer, Pick , Pick .

[0080] The corrected equivalent speed of the signal from the transmitting end to the target interface is calculated. Then, the corrected equivalent velocity of this signal in the asphalt layer. It can be obtained through the following formula:

[0081] (5).

[0082] Specifically, the a priori equivalent velocity of the signal in the asphalt layer It can be obtained through the following formula:

[0083] (6);

[0084] (7);

[0085] Where c is the speed of light. , , , These represent the volume fractions of aggregate, air, ice, and unfrozen water in the asphalt layer, respectively. , , , These represent the dielectric constants of aggregate, air, ice, and unfrozen water in the asphalt layer, respectively. The dielectric constant of aggregate can be determined through core sample dielectric testing. It should be noted that the dielectric constant of unfrozen water is much higher than that of ice and air. The volume fractions of unfrozen water and ice also change with temperature variations. A more accurate actual equivalent dielectric constant of the asphalt layer is obtained by breaking down the total water volume fraction in the asphalt layer into unfrozen water and ice volume fractions, and then combining this with the product of the volume fractions of other components (aggregate and air) and their corresponding dielectric constants. .

[0086] The volume fractions of aggregate, air, ice, and unfrozen water in the asphalt layer are obtained using the following formula:

[0087] (8);

[0088] (9);

[0089] (10);

[0090] (11);

[0091] in, S represents the porosity of the asphalt layer, and S represents the pore water saturation. This represents the volume fraction of total water in the asphalt layer. , and These are calibration constants for the project. Among them, porosity... The volume-mass of the core samples was determined using the Archimedes method, and segmented constants or gradations based on road sections and operating conditions were established. The pore water saturation S is obtained by measuring the total water content through the core sample drying method and converting it to form a segmented constant or graded S value. , and By performing dielectric spectroscopy / time-domain reflectometry tests on representative asphalt materials at multiple temperature points, the temperature-unfrozen water ratio data were obtained and fitted.

[0092] After calculating the corrected equivalent velocity respectively Equivalent speed to prior knowledge Then, the final equivalent velocity of the signal in the asphalt layer. It can be obtained through the following formula:

[0093] (12);

[0094] in, The fusion weights are the corrected equivalent velocities of the signal in the asphalt layer. This represents the fusion weight of the signal's prior equivalent velocity in the asphalt layer. In this embodiment, based on engineering experience, For asphalt pavement with a temperature T less than 0℃ and RH greater than or equal to 50%, take 0.7; for T between -2℃ and 0℃ or T between 0℃ and 2℃ and RH greater than or equal to 70%, take 0.5; for all other cases, take 0.3. Then it is 1 and The difference.

[0095] Specifically, the actual thickness h of the asphalt layer is obtained by the following formula;

[0096] (13).

[0097] To obtain the final equivalent velocity of the signal in the asphalt layer Then, the round-trip time of the signal in the asphalt layer was calculated. The final actual thickness h of the asphalt layer is obtained.

[0098] This application also provides an asphalt paving thickness detection device for performing an asphalt paving thickness detection method. The device includes a moving mechanism, a multi-offset GPR array, a laser altimeter, a temperature and humidity sensor, a differential GPS and IMU, and a control system. The multi-offset GPR array is positioned below the moving mechanism and is used to transmit and receive electromagnetic wave signals to and from the asphalt pavement. The laser altimeter is positioned parallel to the multi-offset GPR array and is used for zero-point compensation of ground elevation changes. The temperature and humidity sensor is positioned at the front of the moving mechanism and close to the asphalt pavement to detect the asphalt pavement temperature and ambient relative humidity. The differential GPS and IMU are positioned at the top of the moving mechanism for position and attitude registration. The control system is located inside the moving mechanism and is electrically connected to the multi-offset GPR array, the laser altimeter, the temperature and humidity sensor, and the differential GPS and IMU.

[0099] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0100] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A method for detecting the thickness of asphalt paving, characterized in that, Includes the following steps: Sending and receiving electromagnetic wave signals to and from the asphalt pavement; The initial equivalent velocities of the signal from the transmitter to the top and bottom surfaces of the asphalt layer are obtained through CMP velocity inversion, and then environmental corrections are applied to obtain the corrected equivalent velocities of the signal within the asphalt layer. ; The actual equivalent dielectric constant of the asphalt layer is calculated based on the volume fraction of each component. And based on the actual equivalent dielectric constant of the asphalt layer Calculate the a priori equivalent velocity of the signal in the asphalt layer ; Corrected equivalent velocity of the signal in the asphalt layer and a priori equivalent speed Weighted fusion is performed to obtain the final equivalent velocity of the signal in the asphalt layer. ; The round-trip time of the signal from the transmitting end to the bottom of the ice layer and from the transmitting end to the bottom of the asphalt layer is obtained in order to calculate the round-trip time of the signal in the asphalt layer. ; Based on the final equivalent velocity of the signal in the asphalt layer and the round-trip time of the signal in the asphalt layer Calculate the actual thickness h of the asphalt layer; The initial equivalent velocity of the signal from the transmitting end to the top and bottom surfaces of the asphalt layer is obtained through CMP velocity inversion, and then environmental correction is applied to obtain the corrected equivalent velocity of the signal in the asphalt layer. It includes the following steps: The initial equivalent velocity of the signal from the transmitting end to the top surface of the asphalt layer was obtained by scanning the CMP velocity spectrum, correcting for normal time difference, and superimposing scores. Round trip time And the initial equivalent velocity of the signal from the transmitting end to the bottom of the asphalt layer. Round trip time ; Asphalt pavement temperature and ambient relative humidity are obtained to calculate environmental weights. ; According to environmental weight The initial equivalent velocities of the signal from the transmitting end to the top and bottom surfaces of the asphalt layer are corrected to obtain the corrected equivalent velocities of the signal from the transmitting end to the top and bottom surfaces of the asphalt layer, respectively. and ; Based on the corrected equivalent velocity from the transmitting end to the top and bottom surfaces of the asphalt layer respectively. and The corrected equivalent velocity of the signal in the asphalt layer was calculated. ; The corrected equivalent velocity of the signal in the asphalt layer It can be obtained through the following formula: ； The environmental weight It can be obtained through the following formula: ； Where T is the asphalt pavement temperature and RH is the ambient relative humidity. Temperature scale; The corrected equivalent speeds of the signal from the transmitting end to the top and bottom surfaces of the asphalt layer, respectively. and It can be obtained through the following formula: ； in, The corrected equivalent speed of the signal from the transmitting end to the target interface. The initial equivalent velocity of the signal from the transmitting end to the target interface; The prior equivalent velocity of the signal in the asphalt layer It can be obtained through the following formula: ； ； Where c is the speed of light. , , , These represent the volume fractions of aggregate, air, ice, and unfrozen water in the asphalt layer, respectively. , , , , respectively, are the dielectric constants of aggregate, air, ice, and unfrozen water in the asphalt layer; The final equivalent velocity of the signal in the asphalt layer It can be obtained through the following formula: ； in, The fusion weights are the corrected equivalent velocities of the signal in the asphalt layer. The fusion weights are the prior equivalent velocities of the signal in the asphalt layer; The actual thickness h of the asphalt layer is obtained by the following formula; 。 2. The method for detecting asphalt paving thickness according to claim 1, characterized in that, The volume fractions of aggregate, air, ice, and unfrozen water in the asphalt layer are obtained using the following formula: ； ； ； ； in, S represents the porosity of the asphalt layer, and S represents the pore water saturation. This represents the volume fraction of total water in the asphalt layer. , and For project calibration constants, , and By performing dielectric spectroscopy or time-domain reflectometry tests on representative asphalt materials at multiple temperature points, the temperature-to-unfrozen-water ratio data were obtained and fitted.

3. An asphalt paving thickness detection device, characterized in that, For performing the asphalt paving thickness detection method as described in any one of claims 1 to 2, the detection equipment includes: Mobile mechanism; A multi-offset GPR array, positioned below the moving mechanism, is used to transmit and receive electromagnetic wave signals to the asphalt pavement; A laser altimeter, arranged in parallel with the multi-offset GPR array, is used for zero-point compensation of time variations in ground elevation. A temperature and humidity sensor is installed at the front of the moving mechanism and close to the asphalt road surface to detect the temperature of the asphalt road surface and the relative humidity of the environment. Differential GPS and IMU are mounted on top of the mobile mechanism for position and attitude registration; The control system is located within the moving mechanism and is electrically connected to the multi-offset GPR array, the laser altimeter, the temperature and humidity sensor, and the differential GPS and IMU, respectively.

Images