JP7424731B2 - Deflection measurement method, deflection measurement system, and deflection measurement program - Google Patents

Description

Application of Article 30, Paragraph 2 of the Patent Act ・October 14, 2021, collection of papers and case reports from the 34th Japan Road Conference (paper number: 3030) ・October 14, 2021, 34th Japan Road Conference Collection of papers and case reports from the Japan Road Conference (paper number: 3031) ・October 14, 2021, collection of papers and case reports from the 34th Japan Road Conference (paper number: 3033) ・October 2021 14th, collection of papers and case reports from the 34th Japan Road Conference (paper number: 3034)

The present invention relates to a deflection measurement method, a deflection measurement system, and a deflection measurement program.

Pavements are subject to changes such as cavities and uneven settlement in the roadbed, roadbed, and road body due to damage to the roadbed and roadbed due to repeated loads caused by vehicle running, accidental effects such as earthquake motion, and the influence of groundwater. Conditions may occur. Therefore, it is necessary to understand not only damage such as rutting and cracks, but also to measure the bearing capacity of the pavement to understand these deformations and maintain the health of the pavement. For this reason, there has been a need for a pavement health evaluation method that non-destructively measures the bearing capacity of pavement.

As a non-destructive measuring device used to evaluate the soundness of pavement, a falling weight deflectometer (FWD) is widely used. However, since FWD needs to be measured in a stationary state, traffic regulations are required and measurement takes time. Therefore, evaluating the overall soundness of pavement over a wide area involves a huge amount of time and cost. Furthermore, since continuous measurement is difficult, there is a risk that local deformations may be overlooked.

In view of these circumstances, Patent Document 1 discloses a dynamic deflection measuring device (MWD) that can non-destructively measure the deflection speed of pavement while driving a loading vehicle (hereinafter also simply referred to as a "vehicle"). :Moving Wheel Deflectometer (hereinafter simply referred to as "MWD") has been proposed. MWD can measure the deflection that occurs continuously on the vehicle running surface as a speed signal, and can efficiently evaluate the soundness of the pavement. The speed derived from the movement of the vehicle is included. Therefore, it is necessary to remove the speed derived from the movement of the vehicle from the measured values.

JP2016-23537A

The deflection measuring method described in Patent Document 1 mentioned above attempts to remove the speed derived from the movement of the vehicle from the measured value. Speeds derived from vehicle movement include variable speeds resulting from vertical movement of the vehicle and variable speeds resulting from changes in the elevation angle of the vehicle, etc., but Patent Document 1 clearly takes into consideration variable speeds resulting from the elevation angle of the vehicle. It has not been. Further, since the deflection measuring method described in Patent Document 1 uses wavelet analysis as an analysis method, there is a possibility that a part of the deflection velocity is removed from the measured value. For this reason, there has been a need for a method to more accurately calculate the maximum amount of pavement deflection.

The present invention has been made in view of these circumstances, and by effectively removing the speed derived from the movement of the vehicle from the measured values, the physical quantity related to the deflection speed is extracted, and the calculated maximum deflection amount is calculated. The purpose of the present invention is to provide a deflection measurement method, a deflection measurement system, and a deflection measurement program that enable improved accuracy.

(1) In order to achieve the above object, the present invention takes the following measures. In other words, it is a deflection measurement method that dynamically measures the deflection of the vehicle running surface where deflection may occur, and the method uses an elevation angle variation meter that detects variations in the vehicle elevation angle in the vehicle traveling direction, and a relative relationship between the vehicle running surface including the deflection speed. A sensor pedestal to which a plurality of Doppler vibrometers for detecting speed is rigidly connected causes the rigidly connected loading vehicle to travel; a step of obtaining a measured value from a vibration meter; a step of removing a speed fluctuation resulting from vertical movement of the vehicle from the measured value by taking a difference between the measured values obtained from the plurality of Doppler vibrometers; The variable speed resulting from the elevation angle fluctuation of the vehicle is removed using the value from which the speed fluctuation resulting from the vertical movement of the vehicle has been removed and the angular velocity based on the fluctuation of the vehicle elevation angle in the vehicle traveling direction obtained from the elevation angle fluctuation meter. and a step of calculating the maximum deflection amount from a physical quantity related to the deflection speed from which the variable speed resulting from vertical movement of the vehicle and the variable speed resulting from elevation angle fluctuation of the vehicle are removed.

In this way, in the present invention, the fluctuation velocity resulting from the vertical movement of the vehicle is removed by taking the difference between the measured values obtained from a plurality of Doppler vibrometers, so the measured values obtained from the Doppler vibrometers are From this, only the variable speed resulting from the vertical movement of the vehicle is removed, and the accuracy of the calculated maximum deflection amount can be improved. In addition, the maximum deflection amount is calculated using a value that removes not only the speed fluctuation resulting from the vertical movement of the vehicle but also the fluctuation speed resulting from the fluctuation in the elevation angle of the vehicle. It is possible to further improve the accuracy of the calculated maximum deflection amount compared to the case where removal of the varying speed is not considered.

(2) In the deflection measuring method of the present invention, in the step of calculating the maximum deflection amount, w is the deflection amount, V is the traveling speed of the cargo vehicle, x is the distance, and t is the time;
When dw/dt is the deflection speed, a is the maximum amount of deflection, b is the coefficient related to the shape of deflection, and d is the position where the maximum deflection occurs, calculate the maximum amount of deflection using the following formulas (F1) and (F2). It is characterized by calculating a.

In this way, since a Gaussian function similar to the deflection shape of the vehicle running surface is used, the maximum deflection amount can be calculated from the measured value obtained from the Doppler vibration meter. Furthermore, since the maximum deflection amount is calculated from the value from which the speed derived from the movement of the vehicle has been removed, it is possible to improve the accuracy of the calculated maximum deflection amount.

(3) In the deflection measuring method of the present invention, in the step of calculating the maximum deflection amount, w is the deflection amount, V is the traveling speed of the cargo vehicle, x is the distance, and t is the time;
When dw/dt is the deflection speed, a is the maximum amount of deflection, b is the coefficient related to the shape of deflection, and d is the position where the maximum deflection occurs, calculate the maximum amount of deflection using the following formulas (F3) and (F4). It is characterized by calculating a.

In this way, since a function similar to the deflection shape of the vehicle running surface is used, the maximum deflection amount can be calculated from the measured value obtained from the Doppler vibration meter. Furthermore, since the maximum deflection amount is calculated from the value from which the speed derived from the movement of the vehicle has been removed, it is possible to improve the accuracy of the calculated maximum deflection amount.

(4) The deflection measurement system of the present invention is a deflection measurement system that dynamically measures the deflection of a vehicle running surface where deflection may occur, and includes a sensor mount that is rigidly connected to a loading vehicle, and a sensor mount that is rigidly connected to the sensor mount. a plurality of Doppler vibrometers that are rigidly connected to the sensor pedestal and detect a relative speed with respect to the vehicle running surface including a deflection speed; By taking the difference between the measured values obtained from the Doppler vibrometer of Using the angular velocity based on the variation of the vehicle elevation angle in the vehicle traveling direction obtained from the elevation angle variation meter, the variation speed originating from the elevation angle variation of the vehicle is removed, and the variation speed originating from the vertical movement of the vehicle and the vehicle progress are removed. a calculation unit that calculates a maximum deflection amount from a physical quantity related to a deflection velocity from which a variation velocity resulting from elevation angle variation of the vehicle in the direction has been removed, and the plurality of Doppler vibrometers are configured to It is characterized in that it is provided at a position that detects the relative velocity with respect to the vehicle running surface, including the deflection velocity, at least one of the front side and the rear side with respect to the vehicle traveling direction.

In this way, in the present invention, the fluctuation velocity resulting from the vertical movement of the vehicle is removed by taking the difference between the measured values obtained from multiple Doppler vibrometers. Only the variable speed resulting from the vertical movement of the vehicle is removed, and the accuracy of the calculated maximum deflection amount can be improved. In addition, the maximum deflection amount is calculated using a value that removes not only the speed fluctuation resulting from the vertical movement of the vehicle but also the fluctuation speed resulting from the fluctuation in the elevation angle of the vehicle. It is possible to further improve the accuracy of the calculated maximum deflection amount compared to the case where the removal of the varying speed is not considered.

(5) In the deflection measurement system of the present invention, at least one of the plurality of Doppler vibrometers is located at a position to detect the relative speed of the wheel with respect to the vehicle running surface, including the deflection speed in front of the wheel with respect to the vehicle traveling direction. The remaining one or more are provided at positions for detecting the relative speed of the wheel with respect to the vehicle running surface, including the rearward deflection speed of the wheel with respect to the vehicle traveling direction.

In this way, since a plurality of Doppler vibration meters are installed at least one each in front and rear of the wheels, it is possible to calculate the result of vertical movement of the vehicle by taking the difference between the measured values obtained from the Doppler vibration meters. When the fluctuating speed is removed, the difference in the deflection speed increases, so it becomes possible to accurately calculate the maximum deflection amount.

(6) In the deflection measurement system of the present invention, the elevation angle variation meter is any one of a gyro sensor, a displacement meter, and an inclinometer. In this way, the elevation angle variation meter can measure the variation in the vehicle elevation angle of the loaded vehicle from any one of the gyro sensor, displacement meter, and inclinometer. In addition, if the elevation angle variation meter is a gyro sensor, it can directly measure the angular velocity of the loading vehicle, reducing the calculation effort compared to displacement meters and inclinometers, which require calculating the angular velocity from the measured value. can do.

(7) The deflection measurement program of the present invention includes: a sensor pedestal rigidly connected to a loading vehicle; an elevation angle variation meter rigidly connected to the sensor pedestal and configured to detect fluctuations in the elevation angle of the vehicle in the vehicle traveling direction; and the sensor pedestal A deflection measuring device that includes a plurality of Doppler vibrometers that are rigidly connected to the vehicle and detects the relative velocity with the vehicle running surface, including the deflection speed, dynamically measures the deflection of the vehicle running surface where deflection may occur. A deflection measurement program that calculates the maximum amount of deflection using the measured value obtained by the deflection measuring device, the program includes a process of obtaining the measured value from the deflection measuring device, and calculating a difference between the measured values obtained from the plurality of Doppler vibrometers. A process of removing the speed fluctuation resulting from the vertical movement of the vehicle from the measured value, and a value from which the speed fluctuation resulting from the vertical movement of the vehicle is removed and the vehicle traveling direction obtained from the elevation angle fluctuation meter. A process of removing a varying speed resulting from a fluctuation in the elevation angle of the vehicle using an angular velocity based on a fluctuation in the elevation angle of the vehicle; The present invention is characterized in that it includes a process of calculating a maximum deflection amount from a physical quantity related to a deflection speed.

In this way, in the present invention, the fluctuation velocity resulting from the vertical movement of the vehicle is removed by taking the difference between the measured values obtained from multiple Doppler vibrometers. Only the variable speed resulting from the vertical movement of the vehicle is removed, and the accuracy of the calculated maximum deflection amount can be improved. In addition, the maximum deflection amount is calculated using a value that removes not only the speed fluctuation resulting from the vertical movement of the vehicle but also the fluctuation speed resulting from the fluctuation in the elevation angle of the vehicle. It is possible to further improve the accuracy of the calculated maximum deflection amount compared to the case where the removal of the varying speed is not considered.

(8) In the deflection measurement program of the present invention, the process of calculating the maximum deflection amount is performed by setting w to the deflection amount, V to the running speed of the cargo vehicle, and x to the distance;
When t is time, dw/dt is the deflection speed, a is the maximum deflection amount, b is the coefficient related to the deflection shape, and d is the position where the maximum deflection occurs, the following formulas (F5) and (F6) are It is characterized in that the maximum deflection amount a is calculated using

In this way, since a Gaussian function similar to the deflection shape of the vehicle running surface is used, the maximum deflection amount can be calculated from the measured value obtained from the Doppler vibration meter. Furthermore, since the maximum deflection amount is calculated from the value from which the speed derived from the movement of the vehicle has been removed, it is possible to improve the accuracy of the calculated maximum deflection amount.

(9) In the deflection measurement program of the present invention, in the process of calculating the maximum deflection amount, w is the deflection amount, V is the traveling speed of the loading vehicle, and x is the distance;
When t is time, dw/dt is the deflection speed, a is the maximum deflection amount, b is the coefficient related to the deflection shape, and d is the position where the maximum deflection occurs, the following formulas (F7) and (F8) are The feature is that the maximum deflection amount a is calculated using

In this way, since a function similar to the deflection shape of the vehicle running surface is used, the maximum deflection amount can be calculated from the measured value obtained from the Doppler vibration meter. Furthermore, since the maximum deflection amount is calculated from the value from which the speed derived from the movement of the vehicle has been removed, it is possible to improve the accuracy of the calculated maximum deflection amount.

According to the present invention, it is possible to improve the accuracy of the calculated maximum deflection amount.

FIG. 3 is an explanatory diagram schematically illustrating a deflection curve and a maximum deflection amount. FIG. 3 is an explanatory diagram schematically illustrating an installation angle. FIG. 2 is an explanatory diagram schematically illustrating a vehicle elevation angle. This is a graph showing the relationship between traveling speed and the position of maximum deflection (excerpted from Kunito Matsui et al., “Current status of traveling road surface deflection measurement test equipment and efforts in Japan”, Civil Engineering Technical Document 52-12, 2013). It is a graph showing the curve shape of Numerical formula (1) and Numerical formula (19). FIG. 1 is a schematic diagram showing the configuration of a deflection measuring device according to the present embodiment. It is a schematic diagram which showed an example of the modification of the deflection measuring device based on this embodiment. It is a schematic diagram which showed an example of the modification of the deflection measuring device based on this embodiment. It is a schematic diagram which showed an example of the modification of the elevation angle variation meter in the deflection measuring device based on this embodiment. FIG. 1 is a block diagram showing a schematic configuration of a deflection measurement system according to the present embodiment. It is a flow chart showing the flow of a deflection measuring method in this embodiment. It is a graph showing an example of a relational expression between the difference in vertical strain and the load on a wheel according to the present embodiment. 5 is a graph showing changes in vehicle elevation angle with respect to travel distance in Example 1. FIG. 5 is a graph showing the variation of sin θ with respect to the variation of the vehicle elevation angle in Example 1. FIG. 5 is a graph showing the variation of cos θ with respect to the variation of the vehicle elevation angle in Example 1. FIG. 3 is a graph showing the velocity difference and angular velocity of the Doppler vibrometer in Example 2. 3 is a graph showing the velocity difference and angular velocity of the Doppler vibrometer in Example 3. 3 is a graph showing the maximum deflection amount a in Example 4 and Comparative Example 1. 3 is a graph showing the maximum deflection amount a in Example 5 and Comparative Example 1. 3 is a graph showing the maximum deflection amount a in Example 6 and Comparative Example 1. 3 is a graph showing the maximum deflection amount a in Example 7 and Comparative Example 1. 3 is a graph showing the maximum deflection amount a in Example 4, Example 8, and Comparative Example 1. 12 is a graph showing the maximum deflection amount a in Example 9, Example 10, and Comparative Example 1. 3 is a graph showing the maximum deflection amount a in Example 4 and Comparative Example 1. 3 is a graph showing the maximum deflection amount a in Comparative Example 1 and Comparative Example 2. 3 is a scatter diagram showing the correlation between Example 4 and Comparative Example 1. FIG. 3 is a scatter diagram showing the correlation between Comparative Example 1 and Comparative Example 2. FIG. 12 is a graph showing the measurement results of the maximum deflection amount a in Example 4 and Example 5. 12 is a graph showing the measurement results of the maximum deflection amount a in Example 11 and Example 12. 12 is a graph showing the measurement results of running speed in Example 11 and Example 12. 12 is a graph showing the measurement results of the maximum deflection amount a in Example 13 and Comparative Example 3. 12 is a graph showing the measurement results of the maximum deflection amount a in Example 14 and Comparative Example 4. 12 is a graph showing the measurement results of the maximum deflection amount a in Example 15 and Comparative Example 5. 12 is a graph showing the measurement results of the maximum deflection amount a in Example 4 and Example 16.

[Principle for calculating maximum deflection amount]
With reference to FIGS. 1 to 4, the principle of the speed derived from the movement of the loading vehicle included in the measurement value of the Doppler vibration meter and the method of calculating the maximum deflection amount taking this into consideration will be explained. FIG. 1 is an explanatory diagram schematically explaining the deflection curve and the maximum deflection amount, FIG. 2A is an explanatory diagram schematically explaining the installation angle of the Doppler vibration meter, and FIG. 2B is an explanatory diagram schematically explaining the vehicle elevation angle. FIG. Further, FIG. 3 is a graph showing the relationship between the traveling speed and the maximum deflection occurrence position, and FIG. 4 is a graph showing the curve shape of the equation (1) and the equation (19).

In this embodiment, a local coordinate system whose origin is directly below the wheel 1 is defined. In this local coordinate system, the x-axis is the vehicle traveling direction TD, which is the direction in which the loading vehicle 10 travels, the y-axis is the extension direction of the axle 1a, and the z-axis is the loading direction LD in which the load is applied to the vehicle running surface Vs. , the vehicle traveling direction TD is the negative direction of the x-axis, and the loading direction LD is the positive direction of the z-axis.

FIG. 1 is a cross-sectional view of the vehicle running surface Vs on which a load is applied by the wheels 1 when the loading vehicle 10 is running. The vehicle running surface Vs draws a concave deflection curve w due to the wheels 1.

When the loading vehicle 10 is stopped, the vertex Po of the deflection curve w is located on the vertical line Ax passing through the center of the axle 1a. In the present invention, since the deflection is measured dynamically, the apex Po of the deflection curve w is located behind the vertical line Ax passing through the center of the axle 1a. At this time, the distance between the origin of the local coordinate system and the vertex Po of the deflection curve w is defined as the maximum deflection occurrence position d. The maximum deflection occurrence position d is based on the material ``Kunito Matsui et al., ``Current situation of traveling type road surface deflection measurement test equipment and efforts in Japan'', Civil Engineering Technical Data 55-12, 2013''.

The deflection curve w is determined by equation (1), where a is the maximum deflection amount, b is the coefficient related to the deflection shape, d is the maximum deflection occurrence position, x is the distance, and V is the traveling speed. Further, the deflection speed dw/dt is determined by equation (2).

FIG. 2A is a schematic diagram schematically showing a Doppler vibration meter LDV provided around the wheel 1 of the loading vehicle 10. In this embodiment, a case will be described in which one deflection measuring device 100 is provided with a total of three Doppler vibration meters LDV1 to LDV3, one in front of the wheel 1 and two in the rear.

The three Doppler vibrometers LDV1 to 3 are referred to as a first Doppler vibrometer LDV1, a second Doppler vibrometer LDV2, and a third Doppler vibrometer LDV3 in order from the front in the vehicle traveling direction TD. Further, a wheel 1 is arranged between the first Doppler vibration meter LDV1 and the second Doppler vibration meter LDV2.

Each of the Doppler vibrometers LDV1-3 irradiates the vehicle running surface Vs with laser light from the irradiation ports IP1-3. Here, in the Doppler vibrometer LDV1, the installation angle θ _LDV1 is the angle between the laser beam shown by the two-dot chain line and the vertical line SP passing through the laser irradiation port IP1, as shown in FIG. 2A. In the Doppler vibrometer LDV1, the optical path length r1 of the laser beam can be expressed by Expression (3), and the value dr1/dt obtained by differentiating the optical path length r1 with respect to time t is expressed by Expression (4). Similarly to r1, r2 is expressed by equations (5) and (6), and r3 is expressed by equations (7) and (8).

At this time, the optical path length is r1, the measurement time is t, and the distance from the irradiation port IP1 of the Doppler vibrometer LDV1 to the intersection I is Lx. Further, the installation height is h, the vehicle elevation angle is θ _M , and the installation angle is θ _LDV1 . Similarly, variables are defined for r2 and r3.

The installation height h is the height at which the Doppler vibrometer is installed when the vehicle elevation angle θ _M is 0°, and the line SL passing through the irradiation ports IP1-3 of the Doppler vibrometers LDV1-3 and the deflection This refers to the distance between the vehicle running surface Vs and the vehicle running surface Vs on which no occurrence occurs. Intersection I is a line extending along the x-axis through the irradiation ports IP1-3 of Doppler vibration meters 1-3 when the vehicle elevation angle θ _M is 0°, and a line extending along the z-axis through the center of rotation M. It is the point of intersection with the extending line.

As shown in FIG. 2B, the vehicle elevation angle θ _M is the angle formed between the vehicle running surface Vs and the loading vehicle 10, and the angle between the line SL passing through the irradiation ports IP1-3 of the Doppler vibration meters LDV1-3 and the vehicle This refers to the angle between the vehicle and the running surface Vs. Note that the vehicle elevation angle θ _M assumes that the direction of the arrow shown in FIG. 2B is positive. The vehicle elevation angle θ _M changes when the loading vehicle 10 travels.

Using the above equations (1) to (4), the measured value u ₁ obtained from the Doppler vibrometer LDV1 can be expressed by the following equation (9). Note that the fluctuation speed resulting from the vertical movement of the loading vehicle 10 is assumed to be Vz. Furthermore, as shown in equation (9), the measured value _u1 includes values other than the deflection speed dw/dt of the vehicle running surface Vs.

Further, when there are three Doppler vibrometers provided in the deflection measuring device 100, the measured values u1 _{to u3} obtained from each Doppler vibrometer LDV1 to LDV3 are as shown in the following equation (10). Note that _L12 is the distance between the irradiation port IP1 of the first Doppler vibrometer and the irradiation port IP2 of the second Doppler vibrometer, and _L23 is the distance between the irradiation port IP2 of the second Doppler vibrometer and the third This is the distance between the irradiation ports IP3 of the Doppler vibrometer. That is, the measured value u ₂ obtained from the Doppler vibrometer LDV2 can be expressed by replacing Lx with (Lx+L ₁₂ ) and replacing θ _LDV1 with θ _LDV2 , as described above. The measured value u ₃ obtained from the Doppler vibrometer LDV3 can be expressed by replacing Lx with (Lx+L ₁₂ +L ₂₃ ) and replacing θ _LDV1 with θ _LDV3 , as described above.

As described above, the measured values u _{1 to 3 obtained from the Doppler vibration meters LDV 1 to 3} include values other than the deflection speed dw/dt of the vehicle running surface Vs. Specifically, it includes a variable speed resulting from a change in the vehicle elevation angle θ _M , a variable speed Vz resulting from vertical movement of the vehicle, and a running speed V. The fluctuation speed derived from the fluctuation of the vehicle elevation angle θ _M is the speed at which the loading vehicle 10 fluctuates in the vehicle elevation angle direction. The fluctuating speed Vz derived from the vertical movement of the vehicle is the speed at which the loading vehicle 10 fluctuates in the vertical direction. The traveling speed V is the speed resulting from the movement of the loading vehicle 10 moving straight in the vehicle traveling direction TD. That is, the fluctuation speed derived from the fluctuation of the vehicle elevation angle θ _M , the fluctuation speed Vz derived from the vertical movement of the vehicle, and the speed derived from the running speed V are all speeds based on the movement of the loading vehicle 10, This is not caused by the deflection of the vehicle running surface Vs. From this, it can be said that the fluctuating speed resulting from the fluctuation of the vehicle elevation angle θ _M , the fluctuating speed Vz resulting from the vertical movement of the vehicle, and the traveling speed V need to be removed from the measured values u _{1 to 3} .

Next, the principle of calculating the maximum deflection amount a after removing the varying speed resulting from the fluctuation of the vehicle elevation angle θ _M , the fluctuating speed Vz resulting from the vertical movement of the vehicle, and the traveling speed V will be explained. First, by taking the difference between the measured values u _{1 to 3 obtained from each of the Doppler vibrometers LDV 1 to 3,} the varying speed Vz resulting from the vertical movement of the vehicle is removed. The following formulas (11) and (12) are calculated from the measurement value u1 obtained from the first Doppler vibrometer LDV1 located at the forefront in the vehicle traveling direction TD, and from the measurement value _u1 obtained from the other Doppler vibrometers LDV2 and LDV3. The equations for subtracting the measured values u ₂ and u ₃ are shown.

Furthermore, since the value of cos θ does not change much in accordance with changes in angle θ, cos θ _M , cos θ _LDV1 , and cos θ _LDV2 may be calculated as 1.0. Furthermore, sin θ _LDV1 ·sin θ _M , sin θ _LDV2 ·sin θ _M , and sin ² θ _M are also considerably small values, and since their influence on the calculated amount of deflection is small, they may be calculated as 0.0.

Here, the difference in the deflection speed dw/dt of the vehicle running surface Vs is expressed using equation (2) as the following equation (13), and expressed using equation (11) as equation (14). Here, x1 and x2 are the laser beam irradiation positions on the x-axis of the Doppler vibrometers LDV1 and LDV2 in the local coordinate system whose origin is directly below the wheel in FIG. 2A.

Since Equation (13) and Equation (14) are connected by an equal sign, they are transformed into Equation (15) below to calculate the maximum deflection amount a.

Furthermore, when _the measured value u 3 of the third Doppler vibrometer LDV3 is used instead of the measured value u ₂ of the second Doppler vibrometer LDV2, the following equation (16) is obtained. Here, x3 is the laser beam irradiation position on the x-axis of the Doppler vibrometer LDV3 in the local coordinate system whose origin is directly below the wheel in FIG. 2A.

When formula (15) and formula (16) are connected with an equal sign, the following formula (17) is obtained. From this equation, the coefficient b regarding the deflection shape can be determined.

At this time, the maximum deflection occurrence position d can be calculated from an approximate expression calculated based on the graph shown in FIG. 3, for example. Figure 3 is a graph showing the relationship between the traveling speed V and the maximum deflection occurrence position d (Kunito Matsui et al., “Current situation of traveling type road surface deflection measuring test equipment and efforts in Japan”, Civil engineering technical data 55-12). , 2013). An example of the approximate expression in this case is the following expression (18).

The maximum deflection amount a is calculated by substituting the calculated coefficient b regarding the deflection shape and the maximum deflection occurrence position d into Equation (15) or Equation (16).

Although the method for calculating the maximum deflection a using a Gaussian function has been described above, the function used to calculate the maximum deflection a may be any curve that approximates the shape of the deflection curve w, for example, using the formula It may be a function shown in (19). As shown in FIG. 4, Equation (19) is a function that draws a curve that approximates a Gaussian function.

In addition, in the case of two Doppler vibrometers, by substituting the coefficient b related to the deflection shape assumed from past measurement results and the maximum deflection occurrence position d into formula (15) or formula (16), The maximum deflection amount a is calculated.

As mentioned above, as a result of intensive research, the present inventors found that among the measured values obtained from the Doppler vibration meter, there are two types of speeds that are derived from the movement of the loading vehicle: a variable speed that is derived from the vertical movement of the vehicle, and a variable speed that is derived from the vertical movement of the vehicle. First, we discovered that the fluctuation speed derived from the elevation angle fluctuation and the traveling speed are included. The present inventors removed the fluctuation speed resulting from the vertical movement of the vehicle by taking the difference between the measured values obtained from multiple Doppler vibrometers, and removed the fluctuation speed resulting from the elevation angle fluctuation of the vehicle. is removed using the angular velocity based on the elevation angle variation obtained from the elevation angle variation meter, and the velocity originating from the running speed is removed using the installation angle of the Doppler vibration meter, and the variation originating from the vertical movement of the vehicle is removed. The present invention has been achieved by discovering a method for calculating the maximum amount of deflection from physical quantities related to the deflection speed excluding the speed, the varying speed resulting from the elevation angle fluctuation of the vehicle, and the traveling speed.

[Configuration of deflection measuring device]
An embodiment that embodies the deflection measuring device, deflection measuring system, and deflection measuring method of this embodiment will be described with reference to FIGS. 5 to 11. In the following, a case will be described in which a Gaussian function is used to calculate the maximum deflection amount, but as described above, the calculation may be performed using a function other than the Gaussian function.

First, the deflection measuring device will be explained with reference to FIGS. 5 to 8. The deflection measuring device 100 dynamically measures the deflection of the vehicle running surface Vs where deflection may occur. The vehicle running surface Vs refers to a running surface on which a vehicle can run and on which it is effective to measure deflection as a target for evaluating soundness. Examples include paved roads, railway rails, and building floors.

FIG. 5 is a partially enlarged view schematically showing the sensor mount 20 and the deflection measuring device 100 around the wheel 1. As shown in FIG. 5, the deflection measuring device 100 includes a sensor mount 20 rigidly connected to the vehicle body 2 of the loading vehicle 10, and an elevation angle variation meter that is rigidly connected to the sensor mount 20 and detects fluctuations in the vehicle elevation angle θ _M. 21, and a plurality of Doppler vibrometers LDV1 to LDV3 which are rigidly connected to the sensor frame 20 and detect relative speeds with respect to the vehicle running surface, including the deflection speed of the vehicle running surface Vs, as measured values. Rigid connection refers to joining members together without shaking, and includes methods such as fastening with bolts and nuts, fitting, welding, and gluing.

The loading vehicle 10 may be a medium-sized vehicle as long as it has wheels 1 that can rigidly connect the sensor frame 20 to the vehicle body 2 and apply a load to the vehicle running surface Vs. At this time, the direction in which the wheels 1 apply a load to the vehicle running surface Vs is defined as the loading direction LD. The loading vehicle 10 does not necessarily need to have a power source itself, and may be a towed device as shown in FIG. 6 . In this case, the loading vehicle 10 may be driven using another vehicle as a power source, or may be driven manually.

As described above, the sensor mount 20 to which the elevation angle variation meter 21 and the Doppler vibration meter LDV are rigidly connected is rigidly connected to the vehicle body 2. Although the shape of the sensor mount 20 is not particularly limited, it is necessary to rigidly connect and integrate sensors such as the elevation angle variation meter 21 and the Doppler vibration meter LDV so that the sensor and the sensor mount 20 move in the same manner. It is necessary to use high-quality materials to create a structure that does not deform. An example is iron.

The Doppler vibrometers LDV1 to LDV3 use laser light to measure the relative speed of the vehicle running surface Vs located below, including the deflection speed, with respect to the vehicle running surface. As shown in FIG. 2A, the Doppler vibration meter LDV1 located in front of the wheel 1 detects the relative speed with the vehicle running surface, including the downward deflection speed, and the Doppler vibration meters LDV2 and 3 located in the rear detect the velocity relative to the vehicle running surface, including the downward deflection speed. , it is desirable to install it at a position that detects the relative velocity with respect to the vehicle running surface, including the upward deflection velocity.

It is sufficient to have a plurality of Doppler vibrometers LDV, and it is even better to have three or more Doppler vibrometers LDV, and the greater the number of Doppler vibrometers LDV, the higher the accuracy of the calculated maximum deflection amount a. On the other hand, the smaller the number of Doppler vibrometers LDV, the more the amount of calculation required to calculate the maximum deflection amount a can be reduced.

Regarding the mounting position and number of Doppler vibration meters LDV, as shown in FIG. It is desirable to be present. Since at least one Doppler vibration meter LDV is provided at each of the front and rear sides of the wheel 1, the difference between the measured values u obtained from the Doppler vibration meter LDV can be calculated to determine the result of the vertical movement of the vehicle. The value becomes larger after removing the influence of fluctuation speed.

Further, the Doppler vibration meters LDV1 to LDV3 may be provided only at the rear of the wheel 1, as shown in FIG. 7, or may be provided only at the front. In short, it is only necessary that the wheel 1 of the loading vehicle 10 be provided at a position where the relative speed with respect to the vehicle running surface, including the deflection speed of the vehicle running surface Vs, can be detected in front or behind with respect to the vehicle traveling direction TD. .

The elevation angle variation meter 21 is, for example, a gyro sensor, a displacement meter, or an inclinometer. The elevation angle variation meter 21 only needs to be able to measure the variation in the vehicle elevation angle θ _M , that is, the variation in the elevation angle θ _M of the loading vehicle 10 in the vehicle elevation angle direction.

In addition, when the elevation angle variation meter 21 is a gyro sensor or an inclinometer, it is sufficient that one is provided in the sensor mount 20. On the other hand, when the elevation angle variation meter 21 is a displacement meter, it is necessary to provide it in front and behind the deflection measuring device 100.

When the elevation angle variation meter 21 is a displacement meter or an inclinometer, it is necessary to calculate the angular velocity G from the following formula (21). At this time, θ _d12 is the angle between the pedestal 20 and the vehicle running surface Vs. Note that θ _d12 assumes that the direction of the arrow shown in FIG. 8 is positive.

Equation (21) is based on Equation (22) below, which can be derived from FIG. FIG. 8 shows a deflection measuring device 100 in which the elevation angle variation meter 21 is a displacement meter. In FIG. 8, the Doppler vibration meter LDV, speed meter 22, strain meter 25, etc. are omitted. As shown in FIG. 8, the distance from the bottom of the displacement meter 21 located at the front of the vehicle 10 to the vehicle running surface Vs is defined as _hd1 , and the distance from the bottom of the displacement meter 21 located at the rear to the vehicle running surface Vs is defined as hd1. h _d2 , and the distance between the displacement meters 21 in the x-axis direction is L _d12 .

Note that, as shown in FIG. 5, the deflection measuring device 100 may further include a speed meter 22 and two or more strain gauges 25. The speedometer 22 measures the traveling speed V of the loading vehicle 10. The strain gauges 25 are provided to measure the load applied to the vehicle running surface Vs, and are mounted so as to face each other in the vertical direction centering on the axle 1a of the wheel 1 that applies the load to the vehicle running surface Vs.

[Deflection measurement system configuration]
As shown in FIG. 9, the deflection measurement system 500 calculates the maximum deflection amount a of the vehicle running surface Vs based on the measurement data measured by the deflection measurement device 100 described above.

As shown in FIG. 9, the deflection measurement system 500 includes a deflection measurement device 100, a deflection calculation device 200, and a display section 300. The deflection measuring device 100 collects data required to calculate the maximum deflection amount a, and outputs the data to the deflection calculating device 200.

The deflection calculation device 200 calculates the maximum deflection amount a from the measurement data output from the deflection measurement device 100. As shown in FIG. 9, the deflection calculation device 200 includes a signal processing section 201, a storage section 202, a calculation section 203, and an operation section 204. Note that measurement data may be input to the deflection calculation device 200 from one or more deflection measurement devices 100.

The signal processing unit 201 converts the analog signal output from the deflection measuring device 100 into a digital signal.

The storage unit 202 is composed of a flash memory or the like, and stores programs and data necessary for processing by the calculation unit 203. The storage unit 202 stores the value of the digital signal converted by the signal processing unit 201 in association with the measurement date and time. It also stores data related to calculation of the maximum deflection amount by the calculation unit.

The calculation unit 203 includes a CPU and a RAM, and calculates the maximum deflection amount a from the value of the digital signal converted by the signal processing unit 201 based on the program and data stored in the storage unit 202.

The operation unit 204 is, for example, a keyboard, a touch panel, a mouse, or the like. Using the operation unit 204, the user can arbitrarily change parameters, calculation formulas, etc. used when calculating the maximum deflection amount a.

The display unit 300 displays information including the maximum deflection amount a calculated by the deflection calculation device 200. The display unit 300 may be a monitor, a tablet, or the like as long as it can visually output the information output from the deflection calculation device 200. The display unit 300 receives information from the deflection calculation device 200 via wired or wireless communication.

[Measurement method of maximum deflection]
Next, with reference to FIG. 10, an example of a method for measuring the maximum amount of deflection will be described. FIG. 10 is a flowchart showing a method for measuring the maximum amount of deflection according to the present invention.

First, the loading vehicle 10 is driven and the deflection of the vehicle running surface Vs is dynamically measured (step S1). At this time, the traveling speed V of the loading vehicle 10 may be constant or may be indefinite. If the running speed is indefinite, the running speed V needs to be measured by the speedometer 22. This allows measurements to be taken without disturbing the flow of traffic on roads in service.

At this time, measurements required for setting correction coefficients for various measured values may be performed. Specifically, measurements may be performed to calculate correction coefficients k12 and k13 regarding the elevation angle variation meter. The method of setting the correction coefficient regarding the elevation angle variation meter 21 will be described in detail below.

First, while the vehicle equipped with the deflection measuring device 100 is stopped, the vehicle is moved in the elevation direction assuming a variation in the vehicle elevation angle θ _M during driving, and only the elevation angle θ _M of the vehicle is varied, and each Doppler Measure the measured values u _{1 to 3 of the vibration meters 1 to 3} and the angular velocity G. When the elevation angle variation meter 21 is a displacement meter or an inclinometer, the angular velocity G is calculated from the measured value as described above. Then, correction coefficients k12 and k13 regarding the elevation angle variation meter are calculated using the following equations (23) and (24). Note that the amplitude value may be one amplitude or both amplitudes.
k12=amplitude value of u1-u2/amplitude value of angular velocity G...(23)
k13=amplitude value of u1-u3/amplitude value of angular velocity G...(24)

Next, the deflection calculation device 200 acquires measurement data from the deflection measurement device 100 (step S2). At this time, the value of the analog signal is converted into a digital signal.

The deflection calculation device 200 uses the installation angles θ _{LDV1 to 3} of each Doppler vibrometer to correct the influence of the installation angles θ LDV1 to 3 on the measured values u _{1 to 3} obtained from the Doppler vibrometers _{LDV1 to 3} . Good too. At this time, the speed component superimposed by the traveling speed V may be removed at the same time. The deflection calculation device 200 calculates correction values WV1 to WV3 of the measured values _{u1 to 3} using the following equation (25). Thereby, the traveling speed V can be removed.
WV1=u1-V・sin( _θLDV1 )
WV2=u2-V・sin( _θLDV2 )
WV3=u3-V・sin( _θLDV3 )...(25)

Next, the deflection calculation device 200 removes the fluctuation speed derived from the vertical movement of the vehicle from the measured value u by taking the difference between the measured values u acquired from the Doppler vibration meter LDV, and The variable speed resulting from the elevation angle variation of the vehicle is removed using the value from which the variation speed has been removed and the angular velocity based on the vehicle elevation angle variation obtained from the elevation angle variation meter (step S3).

That is, the correction value of the measurement value u ₁ obtained from the first Doppler vibrometer LDV1 is set as WV1, the correction value of the measurement value u 2 obtained from the second Doppler vibrometer LDV2 is set as WV2, and the correction value of the measurement value u ₁ obtained from the second Doppler vibrometer LDV2 is set as WV2. When the correction value of the measured value _u3 obtained from the vibration meter LDV3 is WV3, the correction coefficients regarding the elevation angle variation meter are k12 and k13, and the angular velocity measured by the gyro sensor is GYRO, the first Doppler vibration meter LDV1 SIG12, which is a value obtained by removing the fluctuation speed derived from the elevation angle fluctuation of the vehicle, is calculated from the difference between the measured value u ₁ of the second Doppler vibrometer LDV2 and the measured value u ₂ of the second Doppler vibrometer LDV2, SIG13, which is a value obtained by removing the fluctuation speed resulting from the elevation angle fluctuation of the vehicle, is calculated from the difference between the measurement value u ₁ of the vibration meter LDV1 and the measurement value u ₃ of the third Doppler vibration meter LDV3 from equation (27). As a result, from the measured values u _{1 to 3 obtained from the Doppler vibrometers LDV 1 to 3} , the traveling speed, the fluctuation speed resulting from the vertical movement of the vehicle, and the fluctuation speed resulting from the elevation angle fluctuation of the vehicle are removed.
SIG12=WV1-WV2-k12・GYRO...(26)
SIG13=WV1-WV3-k13・GYRO...(27)

Next, the maximum deflection occurrence position d is determined (step S4). As described above, the maximum deflection occurrence position d may be calculated from equation (18), which is an approximate equation.

Next, the deflection calculation device 200 calculates a coefficient b regarding the deflection shape using the following equation (28) (step S5). Here, x1 to x3 are the laser beam irradiation positions on the x-axis of the Doppler vibrometers LDV1 to 3 in the local coordinate system whose origin is directly below the wheel in FIG. 2A.

Next, the deflection calculation device 200 calculates the maximum deflection amount a using the following formula (29) (step S6). The calculated maximum deflection amount a is recorded in the storage unit 202 in association with the measurement date and time.

It is sufficient to have a plurality of Doppler vibrometers LDV, and it is even better to have three or more Doppler vibrometers LDV, and the greater the number of Doppler vibrometers LDV, the higher the accuracy of the calculated maximum deflection amount a. On the other hand, the smaller the number of Doppler vibrometers LDV, the more the amount of calculation required to calculate the maximum deflection amount a can be reduced.

Note that in the case of two Doppler vibrometers, the maximum deflection amount a is calculated using equation (29), assuming a coefficient b regarding the deflection shape based on past measurement results.

The deflection calculation device 200 may perform load correction on the maximum deflection amount a (step S7). Load correction is to correct the load applied to the vehicle running surface Vs to an arbitrary value. By multiplying the maximum deflection amount a by the correction coefficient kw, it is possible to correct the maximum deflection amount a when the load applied to the vehicle running surface Vs is an arbitrary value. For the correction coefficient kw, let E be an arbitrary load value, let α be the slope, let β be the intercept, let ε1 be the strain measured by the strain gauge 25 located above the axle 1a, and let the strain gauge 25 located below the axle 1a be the correction coefficient kw. When the strain measured in 25 is set to ε2, it is calculated by the following equation (30). Thereby, the load applied to the vehicle running surface Vs can be corrected to an arbitrary load value E, and the deflection of the vehicle running surface Vs can be easily evaluated. Moreover, comparison with data measured by other deflection measuring devices 100 with different loads applied to the vehicle running surface Vs is facilitated.
kw=E/(α(ε1−ε2)+β)…(30)

Note that the slope α and the intercept β are the slope and intercept of the linear function shown in FIG. FIG. 11 is a graph showing an example of a relational expression in which the y-axis is the load of the wheel 1 and the x-axis is the vertical strain difference ε1−ε2. Since the slope α and the intercept β vary depending on the loading vehicle 10, when changing the loading vehicle 10, it is necessary to newly find a relational expression between the load on the wheels 1 and the vertical strain difference ε1−ε2. There is.

The relational expression between the load on the wheel 1 and the vertical strain difference ε1−ε2 is obtained by measuring the strain multiple times under conditions where the load on the wheel 1 is different. Specifically, a vehicle weight scale is installed on a flat ground, the loading vehicle 10 is moved so that the wheel 1 is positioned above the installed vehicle weight scale, and the wheel 1 on which the strain gauge 25 is installed is moved. The load acting on the wheel 1 is varied by jacking up a nearby frame, etc., and the load on the wheel 1 and the strain on the upper and lower sides of the axle 1a are measured. While changing the load generated on the wheel 1 by jacking up or the like, the load on the wheel 1 and the strain on the upper and lower sides of the axle 1a are measured multiple times in the same manner. Obtain the slope α and intercept β of the regression line from the measurement results.

The deflection calculation device 200 may apply a median filter to data in which the calculated maximum deflection amount a and measurement time are associated. At this time, the filter length is determined in consideration of the distance of the vehicle running surface Vs to be evaluated, the sampling rate, the running speed V, etc. For example, if you want to evaluate the maximum deflection a of the vehicle running surface Vs in an evaluation section length of 5 m with respect to measurement data measured under the conditions that the traveling speed V is 20 km/h and the sampling rate is 2000 Hz, the filter length should be 1500 to 2000. desirable.

The deflection calculation device 200 may perform temperature correction on the maximum deflection amount a (step S8). Temperature correction means that when the surface to be measured is an asphalt mixture layer, the amount of deflection of the asphalt mixture layer differs depending on the temperature at the time of measurement. This is a correction. As a method for temperature correction, for example, the temperature of the asphalt mixture layer at the time of measurement and the layer of the asphalt mixture layer are There are methods of correcting based on thickness.

Next, the deflection calculation device 200 outputs data (step S9). The deflection calculation device 200 outputs data including the calculated maximum deflection amount a to the display unit 300. The display unit 300 displays data output from the deflection calculation device 200.

The maximum amount of deflection calculated in this way is compared to the case where the maximum amount of deflection a is calculated without taking into account the speed of fluctuation resulting from vertical movement of the vehicle and the speed of fluctuation resulting from elevation angle fluctuation of the vehicle. The accuracy of calculation has been improved, making it possible to accurately grasp the deflection of the vehicle running surface.

(Example 1)
First, the inventors investigated the range in which the sum of the installation angle of the Doppler vibrometer LDV and the vehicle elevation angle (θ _LDV + θ _M ) fluctuates, and the relationship between sin (θ _{LDV +} θ _M ) and cos (θ _{LDV +} θ _M ). The impact was verified. The Doppler vibrometer LDV was installed so that the installation angle θ _LDV was about 2.0°.

As shown in Figure 12, the displacement meter measured the variation in the sum of the installation angle and elevation angle (θ _LDV + θ _M ) of the Doppler vibration meter LDV during the course of approximately 1400 m, and the result was 1.3° to 2.5°. It was found that it fluctuates between. In view of this, the fluctuations of sin θ and cos θ in the range of θ from 0.0° to 3.0° are shown graphically. FIG. 13 shows the variation in sin θ, and FIG. 14 shows the variation in cos θ. From the results shown in FIGS. 13 and 14, it was found that sin θ is easily affected by fluctuations in θ, whereas cos θ is not so affected by fluctuations in θ. From this, the variation in cos θ has almost no effect on the calculation of the maximum deflection amount a, so there is no problem in calculating with cos θ = 1.0.

(Examples 2 and 3)
Next, the present inventors considered whether or not the correction coefficients k12 and k13 regarding the elevation angle variation meter 21 are necessary.

In order to calculate the maximum deflection amount a in Examples 2 and 3, a first Doppler vibrometer LDV1 and a second Doppler vibrometer LDV2 were installed. Note that the installation angle θ _LDV1 of the first Doppler vibrometer was 2.31°, and the installation angle θ _LDV2 of the second Doppler vibrometer was 2.09°. Then, with the deflection measuring device 100 stopped, the vehicle was moved in the direction of the elevation angle of the vehicle, assuming a variation in the vehicle elevation angle θ _M during running. As shown in FIGS. 15 and 16, the measurement value u was measured by each Doppler vibrometer for 10 seconds, and the angular velocity G was measured by the gyro sensor.

In the second embodiment, the difference between the measured value u1 of the first Doppler vibrometer LDV1 and the measured value u2 of the second Doppler vibrometer LDV2 is defined as u1-u2, and the angular velocity G measured by the gyro sensor is This is a case where the correction coefficient k12 is not multiplied. FIG. 15 shows the velocity difference and the angular velocity before correction of such a Doppler vibrometer.

In the third embodiment, the difference between the measured value u1 of the first Doppler vibrometer LDV1 and the measured value u2 of the second Doppler vibrometer LDV2 is defined as u1-u2, and the difference is calculated with respect to the angular velocity measured by the gyro sensor. In this case, the angular velocity G is obtained by multiplying the correction coefficient k12 by the correction coefficient k12. The correction coefficient k12 was set to 0.438, and the correction coefficient k13 was set to 0.703. FIG. 16 is a graph showing the velocity difference and corrected angular velocity of such a Doppler vibrometer.

As mentioned above, FIG. 15 shows the results of Example 2, and FIG. 16 shows the results of Example 3. At this time, the left vertical axis is velocity (m/s), the right vertical axis is angular velocity (rad/s), and the horizontal axis is measurement time (s). Comparing FIG. 15 and FIG. 16, in FIG. 15, the phases match, but the values do not match. On the other hand, in FIG. 16, it can be seen that the difference between the measured value u1 of the first Doppler vibrometer LDV1 and the measured value u2 of the second Doppler vibrometer LDV2 and the angular velocity G match. From this, it can be seen that the correction coefficient k12 is necessary. Note that the same applies to the correction coefficient k13.

(Examples 4 to 7, Comparative Example 1)
Next, the present inventors compared the measurement results by FWD and the measurement results by the present invention. Furthermore, the effectiveness of removing speed fluctuations resulting from fluctuations in the elevation angle of the vehicle using the correction coefficients k12 and k13 was also verified.

In Example 4, as shown in FIG. 5, three Doppler vibrometers LDV1 to LDV3 and a gyro sensor 21 were installed in the deflection measuring device 100. At this time, the installation angle θ _LDV1 of the first Doppler vibrometer LDV1 is 2.31°, the installation angle θ _LDV2 of the second Doppler vibrometer LDV2 is 2.09°, and the third Doppler vibrometer LDV3 The installation angle _θLDV3 was 2.12°. Further, the measurement was performed at a running speed V of 20 km/h. Furthermore, when calculating the maximum deflection amount a, the variation speed resulting from the elevation angle variation of the vehicle was removed using correction coefficients k12 and k13. The correction coefficient k12 was set to 0.438, and the correction coefficient k13 was set to 0.703. Further, the sampling rate was 2000 Hz, the load after load correction was 49 kN, and the filter length of the median filter was 1600. In addition, the irradiation positions of the vehicle running surface by Doppler vibrometers 1 to 3 were set to -0.207 m, +0.205 m, and +0.615 m, respectively, with the point directly below the wheels being 0.000 m.

Example 5 is the same as Example 4 except that the running speed was 40 km/h.
Embodiment 6 is similar to Embodiment 4, except that when calculating the maximum deflection amount a, the variation speed resulting from the elevation angle variation of the vehicle is not removed using the correction coefficients k12 and k13.

In Example 7, the running speed is 40 km/h, and the variations in speed due to elevation angle fluctuations of the vehicle using correction coefficients k12 and k13 are not removed when calculating the maximum deflection amount a. It is the same as 4.

Moreover, as Comparative Example 1, measurement was performed by FWD. In Comparative Example 1, the load applied to the vehicle running surface Vs was 49 kN, and measurements were taken every 5 m.

FIGS. 17 to 20 are graphs showing the measurement results by FWD of Comparative Example 1 and the measurement results of each example. FIG. 17 shows the results of Example 4, and FIG. 18 shows the results of Example 5. FIG. 19 shows the results of Example 6, and FIG. 20 shows the results of Example 7. The vertical axis shows the calculated maximum deflection amount a, and the horizontal axis shows the travel distance.

As shown in FIGS. 17 and 18, it can be seen that Examples 4 and 5 show results that are almost the same as the results measured by FWD.

On the other hand, Examples 6 and 7, as shown in FIGS. 19 and 20, show a tendency similar to the FWD measurement results, but the maximum deflection amount a fluctuates sharply, and the vehicle running surface It is difficult to understand the deflection of Vs.

(Example 4, Examples 8 to 10, Comparative Example 1)
Next, the inventors verified the position where the Doppler vibration meter is installed and the influence of load correction.

Example 8 is the same as Example 4 except that no load correction was performed.
Embodiment 9 is the same as Embodiment 4, except that three Doppler vibration meters LDV are provided behind the axle 1a, as shown in FIG.
Example 10 is the same as Example 9 except that no load correction was performed.

In FIGS. 21 and 22, the results of Comparative Example 1 are shown by solid lines. In addition, in FIG. 21, the results of Example 4 are shown with a chain double-dashed line, the results of Example 8 are shown with a dotted line, and in FIG. 22, the results of Example 9 are shown with a chain double-dashed line, The results of Example 10 are shown by the dotted line. Note that the vertical axis in FIGS. 21 and 22 is the maximum deflection amount a, and the horizontal axis is the traveling distance.

In FIG. 21, the difference between the solid line showing Comparative Example 1, which is the FWD result, and the two-dot chain line and dotted line showing the results of Examples 4 and 8 is small, whereas in FIG. There is a big difference between From this, by installing at least one Doppler vibration meter in front and behind the wheel, it is possible to increase the difference in deflection speed originating from the vehicle running surface, and the results are almost the same as those measured by FWD. can be obtained.

In addition, in FIG. 21, when comparing the two-dot chain line showing Example 4 with load correction and the dotted line showing Example 8 without load correction, Example 4 has a higher maximum deflection amount a. Fluctuations and magnitudes are similar to those of Comparative Example 1. Therefore, by performing load correction, the accuracy of the calculated maximum deflection amount a can be improved, and the maximum deflection amount a of the vehicle running surface can be accurately evaluated.

(Example 4, Comparative Examples 1 and 2)
Next, the present inventors compared a method of measuring the maximum deflection amount a using a conventional dynamic deflection measuring device (Japanese Patent Application Laid-open No. 2016-23537) with the measuring method of the present invention. In addition, the accuracy of the maximum deflection amount a was evaluated by comparing the results measured by FWD and each result. The measurement method of the present invention was carried out under the same conditions as in Example 4. Measurement by FWD was performed under the same conditions as in Comparative Example 1.

Comparative Example 2 differs from Example 4 in that the maximum deflection amount a was calculated by wavelet analysis, which is a conventional technique (Japanese Patent Application Publication No. 2016-23537), and in the irradiation position of the vehicle running surface by Doppler vibrometers 1 to 3. . That is, the measurements were carried out under the same conditions as in Example 4, except that the irradiation positions of the vehicle running surface by Doppler vibrometers 1 to 3 were different. In addition, the wavelet coefficient (filter level) during wavelet inverse transformation was set to 12, and the irradiation positions of Doppler vibration meters 1 to 3 were set to +0.155 m, +0.357 m, and +0.560 m, respectively, with the point directly below the wheel being 0.000 m. .

23 and 24 are graphs showing the maximum deflection amount a. The vertical axis shows the maximum deflection amount a, and the horizontal axis shows the traveling distance. FIG. 23 is a graph comparing Example 4 and Comparative Example 1, and FIG. 24 is a graph comparing Comparative Example 1 and Comparative Example 2. In FIGS. 23 and 24, the measurement results of Example 4 and Comparative Example 2 are shown by solid lines, and the measurement results of Comparative Example 1 are shown by dotted lines.

25 and 26 are scatter diagrams showing the correlation with Comparative Example 1. The vertical axis in FIG. 25 indicates the maximum deflection amount a in Example 4, and the vertical axis in FIG. 26 indicates the maximum deflection amount a in Comparative Example 2. The horizontal axis in FIGS. 25 and 26 indicates the maximum deflection amount a of Comparative Example 1.

Furthermore, in FIGS. 25 and 26, the approximate straight line is shown as a dotted line. Furthermore, the equation of the approximate straight line and the coefficient of determination ^R2 are shown at the lower right. As shown in FIG. 25, the approximate straight line in Example 4 is y=1.0606x−0.2502, and the coefficient of determination R ² is 0.7582. As shown in FIG. 26, the approximate straight line in Comparative Example 2 is y=0.7981x+0.0871, and the coefficient of determination ^R2 is 0.4104.

As shown in FIG. 23, Example 4 has a small number of outliers and exhibits values close to those of Comparative Example 1. It can also be seen that the slope of the approximate straight line in FIG. 25 is close to 1.

On the other hand, Comparative Example 2 is different from Comparative Example 1, which is the FWD measurement result, because there are many variations in FIG. 24 and the slope of the approximate straight line and the value of the coefficient of determination ^R2 in FIG. It can be seen that the correlation is weaker than in Example 4. Further, from FIG. 26, it can be seen that the values of Comparative Example 2 are extremely different from those of Comparative Example 1.

From this, Example 4 has a stronger correlation with the FWD measurement results than Comparative Example 2. Therefore, compared to the conventional technology, the measurement method of the present invention dynamically measures the deflection of the vehicle running surface. However, it can be said that results close to those obtained when measuring with FWD can be obtained. In addition, in the wavelet analysis of Comparative Example 2, the calculation tends to be complicated because the speed derived from the movement of the vehicle is removed by the wavelet analysis, but in Example 4, the calculation is likely to be complicated by taking the difference between the measured values of the Doppler vibration meter, etc. Since the speed derived from the movement of the vehicle is removed, the amount of calculation required to calculate the maximum deflection amount a can be reduced.

Furthermore, in the fourth embodiment, if there is at least one piece of data measured at a certain time, the maximum deflection amount a can be calculated. On the other hand, in Comparative Example 2, continuous measurement data over a certain time period is required in order to remove the speed derived from the movement of the vehicle based on wavelet analysis. According to the fourth embodiment, the maximum deflection amount a can be calculated from the measurement data at one point at a certain measurement time, since the speed derived from the movement of the vehicle is removed by taking the difference between the measured values of the Doppler vibration meter, etc. Become.

(Example 4, Example 5, Example 11, Example 12)
Next, the inventors investigated the influence of fluctuations in running speed on the measurement of the maximum deflection amount a.

As an example in which the traveling speed was constant, measurements were each made twice under the same conditions as in Example 4 and Example 5. As an example in which the running speed is unstable, Example 11 where the running speed was varied in the range of 10 to 25 km/h and Example 12 where the running speed was varied in the range of 10 to 40 km/h were measured twice each. did. Note that Examples 11 and 12 have the same conditions as Example 4 except for the traveling speed.

27 shows the measurement results of the maximum deflection amount a of Example 4 and Example 5, FIG. 28A shows the measurement result of the maximum deflection amount a of Example 11 and Example 12, and FIG. 28B shows the measurement results of the running speed of Example 11 and Example 12.

Comparing FIG. 27 and FIG. 28A, the maximum deflection amount a shows almost the same value. From this, it was found that the presence or absence of a change in running speed has almost no effect on the value of the calculated maximum deflection amount a. Furthermore, in FIG. 27 or FIG. 28A, there was almost no difference between the first and second measurements, indicating that highly reproducible results were obtained. Furthermore, since there is almost no difference in the measurement results between Examples 4 and 5, which have different running speeds, and between Examples 11 and 12, it can be assumed that almost the same results can be obtained regardless of the running speed. I can say that. Furthermore, as shown in FIG. 28B, it was found that although there was a slight difference in the manner in which the traveling speed fluctuated in Examples 11 and 12, it had almost no effect on the value of the calculated maximum deflection amount a.

In other words, the magnitude of the traveling speed and the presence or absence of fluctuation have almost no influence on the measurement results, so even if the traveling speed is varied, the deflection of the vehicle traveling surface Vs can be measured. Therefore, deflection can be measured without traffic regulation, making it easy to measure deflection on an actual road.

(Examples 13 to 15, Comparative Examples 3 to 5)
Next, it was tested in different locations. As Examples 13 to 15, measurements were performed twice at various locations on actual roads in Tsukuba City. FIG. 29 shows the results of Example 13 (measurement point A) and Comparative Example 3, FIG. 30 shows the results of Example 14 (measurement point B) and Comparative Example 4, and FIG. 31 shows the results of Example 15. (Measurement point C) and the results of Comparative Example 5 are shown. Note that Comparative Examples 3 to 5 are the same as Comparative Example 1 except that the measurement locations are different.

In Examples 13 to 15, the maximum deflection amount a has almost the same value as Comparative Examples 3 to 5, which indicates that the maximum deflection amount a can be accurately measured even at different locations. confirmed.

(Example 4, Example 16)
Next, the present inventors verified whether the same results as the Gaussian function could be obtained even if a function other than the Gaussian function that approximated the shape of the deflection curve w was used to calculate the maximum amount of deflection.

Example 16 differs from Example 4 in that the maximum deflection amount a was calculated using Equation (19). FIG. 32 shows the measurement results of the maximum deflection amount a of Example 4 and Example 16. As shown in FIG. 32, it was confirmed that the values were almost the same even if the functions were different.

As explained above, according to the present embodiment, the fluctuation velocity resulting from the vertical movement of the vehicle is removed by taking the difference between the measured values obtained from a plurality of Doppler vibration meters. Only the fluctuation speed resulting from the vertical movement of the vehicle is removed from the measured values, and the accuracy of the calculated maximum deflection amount can be improved. In addition, since we use values that have been removed not only for the speed fluctuations resulting from the vertical movement of the vehicle, but also for the speed fluctuations resulting from the fluctuations in the elevation angle of the vehicle, it is possible to further improve the accuracy of the calculated maximum deflection amount. It becomes possible. Furthermore, since the maximum deflection amount a can be calculated even if the traveling speed varies, measurement on the actual road becomes easy.

1 Wheel 1a Axle 2 Vehicle body 10 Loading vehicle 20 Sensor mount 21 Elevation angle variation meter 22 Speed meter 25 Strain meter 100 Deflection measurement device 200 Deflection calculation device 201 Signal processing section 202 Storage section 203 Calculation section 204 Operation section 300 Display section 500 Deflection measurement System a Maximum amount of deflection b Coefficient related to deflection shape d Maximum deflection occurrence position h Installation height r Optical path length t Measurement time u Measured value V Traveling speed w Deflection curve x Distance dw/dt Deflection speed dr/dt Time differentiation of optical path length r Value Ax Vertical line I passing through the center of the axle Intersection IP Irradiation port LD Loading direction L _d1 Distance L from the bottom of the displacement meter located at the front of the vehicle 10 to the vehicle running surface _{Vs d2} Displacement meter located at the rear of the vehicle 10 Distance L from the bottom of the vehicle to the vehicle running surface Vs _d12 Distance in the x-axis direction between the displacement meters 12 LDV Doppler vibration meter LDV1 First Doppler vibrometer LDV2 Second Doppler vibrometer LDV3 Third Doppler vibrometer Lo Each Doppler Distance between vibration meters Lx Distance from irradiation port IP of Doppler vibration meter to intersection I Lz Distance from rotation center M to intersection I is Lz
L ₁₂ Distance between the first Doppler vibrometer and the second Doppler vibrometer L ₂₃ Distance M between the second Doppler vibrometer and the third Doppler vibrometer Elevation center Po Vertex SP of the deflection curve Passes through the irradiation port IP Vertical line SL Line TD passing through the irradiation port IP of the Doppler vibration meter LDV Vehicle traveling direction Vs Vehicle running surface Vz Variation speed due to vertical movement of the vehicle θ _LDV installation angle θ _M Vehicle elevation angle

Claims (9)

A deflection measurement method for dynamically measuring deflection of a vehicle running surface where deflection may occur, the method comprising:
For loading, a sensor frame is rigidly connected to which an elevation angle variation meter that detects changes in the vehicle elevation angle in the vehicle traveling direction and multiple Doppler vibrometers that detect relative speeds with the vehicle running surface including deflection speed. a step of driving the vehicle;
acquiring measurements from the elevation angle variation meter and the plurality of Doppler vibrometers while the cargo vehicle is traveling;
removing a varying speed resulting from vertical movement of the vehicle from the measured values by taking a difference between the measured values obtained from the plurality of Doppler vibrometers;
Using the value from which the speed fluctuations resulting from the vertical movement of the vehicle have been removed and the angular velocity based on the fluctuations in the vehicle elevation angle in the vehicle traveling direction obtained from the elevation angle fluctuation meter, the speed fluctuations resulting from the fluctuations in the elevation angle of the vehicle are removed. and calculating a maximum amount of deflection from a deflection velocity from which a velocity variation resulting from vertical movement of the vehicle and a variation velocity originating from variation in elevation angle of the vehicle are removed. The step of calculating the maximum deflection amount includes:
w is the amount of deflection, V is the traveling speed of the aforementioned cargo vehicle, x is the distance,
When t is time, dw/dt is the deflection speed, a is the maximum deflection amount, b is the coefficient related to the deflection shape, and d is the position where the maximum deflection occurs, the following formulas (F1) and (F2) are 2. The method for measuring deflection according to claim 1, wherein the maximum deflection amount a is calculated using the following method.
The step of calculating the maximum deflection amount includes:
When w is the amount of deflection, x is the distance, a is the maximum amount of deflection, b is the coefficient related to the shape of deflection, and d is the position where the maximum deflection occurs, use the following formulas (F3) and (F4). 2. The deflection measuring method according to claim 1, further comprising calculating a maximum deflection amount a.
A deflection measurement system that dynamically measures deflection of a vehicle running surface where deflection may occur,
a sensor mount rigidly connected to a loading vehicle;
an elevation angle variation meter that is rigidly connected to the sensor frame and detects a variation in the vehicle elevation angle in the vehicle traveling direction;
a plurality of Doppler vibrometers that are rigidly connected to the sensor mount and detect velocity relative to the vehicle running surface, including deflection velocity;
By taking the difference between the measured values obtained from the plurality of Doppler vibrometers, the variable speed resulting from the vertical movement of the vehicle is removed from the measured value, and the variable speed resulting from the vertical movement of the vehicle is removed. Using the obtained value and the angular velocity based on the variation of the vehicle elevation angle in the vehicle traveling direction obtained from the elevation angle variation meter, the variation velocity originating from the elevation angle variation of the vehicle is removed, and the variation velocity originating from the vertical movement of the vehicle and the angular velocity derived from the elevation angle variation of the vehicle are removed. a calculation unit that calculates the maximum amount of deflection from the deflection speed from which variable speed due to elevation angle variation of the vehicle has been removed;
The plurality of Doppler vibrometers are provided at positions for detecting the relative speed of any of the wheels of the cargo vehicle to the vehicle running surface, including the deflection speed, at least one of the front and rear sides with respect to the vehicle traveling direction. A deflection measurement system featuring: At least one of the plurality of Doppler vibrometers is provided at a position to detect the relative velocity of the wheel with respect to the vehicle running surface, including the forward deflection speed of the wheel with respect to the vehicle traveling direction, and the remaining one or more 5. The deflection measuring system according to claim 4, wherein the deflection measuring system is provided at a position for detecting a varying speed of the vehicle running surface including a backward deflection speed with respect to the vehicle traveling direction. 6. The deflection measurement system according to claim 4, wherein the elevation angle variation meter is one of a gyro sensor, a displacement meter, and an inclinometer. a sensor pedestal rigidly connected to the loading vehicle; an elevation angle variation meter rigidly connected to the sensor pedestal to detect variations in the vehicle elevation angle in the vehicle traveling direction; The maximum amount of deflection is determined using the measured values obtained by dynamically measuring the deflection of the vehicle running surface where deflection may occur using a deflection measurement device including multiple Doppler vibrometers that detect the relative velocity with the surface. A deflection measurement program that calculates
a process of acquiring the measured value from the deflection measuring device;
A process of removing a fluctuation speed resulting from vertical movement of the vehicle from the measured value by taking a difference between the measured values obtained from the plurality of Doppler vibration meters;
Using the value from which the speed fluctuations resulting from the vertical movement of the vehicle have been removed and the angular velocity based on the fluctuations in the vehicle elevation angle in the vehicle traveling direction obtained from the elevation angle fluctuation meter, the speed fluctuations resulting from the fluctuations in the elevation angle of the vehicle are removed. processing and
A deflection measurement program comprising: calculating a maximum deflection amount from a deflection velocity from which a variation speed resulting from vertical movement of the vehicle and a variation speed resulting from elevation angle fluctuation of the vehicle are removed. The process of calculating the maximum deflection amount is as follows:
w is the amount of deflection, V is the traveling speed of the aforementioned cargo vehicle, x is the distance,
When t is time, dw/dt is the deflection speed, a is the maximum deflection amount, b is the coefficient related to the deflection shape, and d is the position where the maximum deflection occurs, the following formulas (F5) and (F6) are 8. The deflection measurement program according to claim 7, wherein the maximum deflection amount a is calculated by using the deflection measurement program.
The process of calculating the maximum deflection amount is as follows:
w is the amount of deflection, V is the traveling speed of the loading vehicle, x is the distance, t is the time,
When dw/dt is the deflection speed, a is the maximum amount of deflection, b is the coefficient related to the shape of deflection, and d is the position where the maximum deflection occurs, calculate the maximum amount of deflection using the following formulas (F7) and (F8). 8. The deflection measuring program according to claim 7, further comprising calculating a.