JP6095209B2 - Deflection measuring machine for paved road surface and method for measuring deflection of paved road surface - Google Patents

Description

  The present invention relates to a pavement surface deflection measuring machine and a pavement surface deflection measuring method for measuring a pavement surface deflection while being attached to a vehicle body and moving.

  In recent years, the paved road surface of a road has shifted from the new construction to the maintenance and repairing era, like a bridge, and a method for quickly and accurately evaluating the soundness of the paved road surface is required. For the soundness of the paved road surface, it is necessary that there is little damage such as rutting, cracking, etc. In addition to this, it is necessary that the bearing capacity of the paved road surface satisfies the design value. In other words, on the pavement, the roadbed, roadbed, and road body have cavities and imperfections due to damage to the roadbed and roadbed due to repeated loads caused by traveling of the vehicle, accidental effects such as earthquake motion, and the effects of groundwater. Deformation such as equal subsidence occurs, so it is necessary to grasp such deformation and maintain the soundness of the paved road surface by measuring the bearing capacity. Therefore, there is a need for a method for evaluating the degree of soundness of a paved road surface that nondestructively measures the bearing capacity of the paved road surface.

As a non-destructive measuring machine used for evaluating the soundness of a paved road surface, an FWD (Falling Weight Defect) which is a vehicle-mounted deflection measuring machine is widely used. This FWD is related to a device that drops a weight onto a paved road surface in a stationary state and measures the shape of the road surface that is deformed by the impact load, a load meter that measures the impact load, and a displacement meter that measures the deflection amount of the road surface. The soundness of the paved road surface can be evaluated based on the measurement results of these measuring instruments.
However, since FWD measures the deflection of the paved road surface for each measurement point, it cannot continuously evaluate the deflection of the paved road surface. Therefore, when assessing the soundness of the entire paved road surface over a wide area, it is necessary to repeat the measurement for each point, and each time it is necessary to move, re-install, and measure the deflection of the FWD. It takes time and money. Moreover, since the measurement by FWD is performed in a stationary state, traffic regulation is required, and the burden of road surface management is large. Furthermore, in order to perform an evaluation without leakage, measurement of deflection is performed with the measurement points set at narrow intervals. However, there is a limit to the measurement, and local deformation may not be confirmed. is there.

For these reasons, a mobile deflection measuring device has been proposed as a measuring device that continuously measures the deflection of a paved road surface while moving (see, for example, Patent Document 1).
This mobile deflection measurement device uses a displacement sensor or Doppler sensor mounted on the body of a traveling vehicle to measure the distance between the sensor and the road surface, thereby continuously measuring the amount of deflection of the paved road surface while moving. doing.
By the way, when the vehicle travels on an uneven paved road surface, it is affected by shocking vibration generated in the vehicle body due to the unevenness. This shocking vibration is converted into vibration having a relatively long period by the seismic isolation effect due to the suspension and weight of the vehicle body and becomes vibration noise. This vibration noise appears differently for each vehicle position depending on the driving environment of the vehicle body and road surface. Therefore, the method of measuring deflection by installing sensors at multiple positions measures the effect of vibration at each vehicle position. The result is irregularly included, and it is difficult to remove vibration noise.
Therefore, when evaluating the soundness of a realistic pavement road surface with unevenness, this mobile deflection measuring device cannot accurately measure between the sensor and the road surface, causing a problem in the evaluation result.

For this reason, when the sensor is attached to the vehicle body and the deflection of the pavement road surface is measured, a device such as attaching a vibration control device to the mount to which the sensor is attached has been devised (for example, see Non-Patent Documents 1 and 2).
However, in order to mount the vibration damping device, it is necessary to use a special large vehicle, and there is a problem that the construction of a measurement system becomes large. Moreover, there is a problem that the soundness of the paved road surface cannot be evaluated on such an intricate road where a large vehicle cannot enter.

Japanese National Patent Publication No. 11-503520

Samer W. Katicha et al. , Estimation of Pavement TSD Slope Measurements Repeatability from a Single Measurement Series, TRB 2012 Annual Meeting Soren, Rasmussen et al. , A comparison of two years of network level measurements with the Traffic Speed Defectometer, TRA Europe 2008, Ljubljana

  An object of the present invention is to solve the above-described problems and achieve the following objects. That is, an object of the present invention is to provide a pavement surface deflection measuring machine and a pavement surface deflection measuring method capable of accurately evaluating the soundness of a pavement surface simply and efficiently.

Means for solving the problems are as follows. That is,
<1> A sensor support portion that is disposed at an axle position of the vehicle in the traveling direction of the vehicle and supports a deflection measurement displacement sensor that measures a distance between the traveling direction and a pavement road surface orthogonal to the traveling direction, and is mounted on the axle. , possess a bearing section which allows supporting the sensor support in a non-rotating state with respect to the rotation of the axle, and the sensor mount to the sensor support is extended in the running direction of the vehicle, and further, the At least two each of the travel directions at the front and rear positions in the travel direction around the deflection measurement displacement sensor and at a distance of less than 1R with respect to the radius R of the wheel from the deflection measurement displacement sensor. It said distance deflected state measuring displacement sensor for measuring the said pavement surface in the perpendicular direction is disposed deflection measuring machine pavement surface, characterized in Rukoto with.
<2> The sensor support portion includes a sensor mount that extends in the traveling direction of the vehicle, and a deflection measurement displacement sensor with respect to the sensor mount, and a symmetrical position about the deflection measurement displacement sensor in the travel direction. And the distance between the traveling direction and the pavement surface perpendicular to the traveling direction is measured at a position separated from the deflection measurement displacement sensor by a distance of 0.4R to 5R with respect to a radius R of a wheel attached to the axle. The pavement surface deflection measuring device according to <1>, wherein the pair of displacement sensors are arranged .
< 3 > A plate-shaped first frame portion supported by the bearing portion and vertically suspended in the bearing portion, and a sensor support portion that is bent substantially L-shaped from the top to the wheel direction with respect to the first frame portion. A hanger frame having a plate-like second frame portion provided, and supported on the bottom side of the first frame portion, in a horizontal state at the outer peripheral position of the wheel, and with two sides parallel to the traveling direction It is arranged so as to span a rectangular frame to be installed and one of the two sides of the frame or the other two sides orthogonal to the traveling direction of the frame. A sensor base that is a long plate-like member, and a hanger part that is suspended and supported by the hanger frame and that suspends the frame base at positions on both ends of the sensor base at the suspension end side. deflection <1> from the paved road surface according to any one of <2> Joki.
< 4 > A method for measuring the deflection of the pavement surface using the pavement surface deflection measuring device according to <1>, wherein the distance between the deflection measurement sensor and the pavement surface measured by the deflection measurement sensor. A difference calculation step for calculating a difference between the reference distance and a deflection state measurement displacement sensor, the maximum deflection position of the paved road surface is estimated, and the distance between the deflection measurement sensor and the paved road surface is determined as the maximum deflection position. A deflection measurement method for a pavement road surface, comprising: a maximum deflection correction step for correcting the deflection measurement sensor to a distance between the pavement road surface.
< 5 > A method for measuring the deflection of the pavement surface using the pavement surface deflection measuring machine according to <2>, wherein the distance between the deflection measurement sensor and the pavement surface measured by the deflection measurement sensor. A difference calculation step for calculating a difference between the reference distance and a deflection state measurement displacement sensor, the maximum deflection position of the paved road surface is estimated, and the distance between the deflection measurement sensor and the paved road surface is determined as the maximum deflection position. A maximum deflection correction step for correcting the distance between the deflection measurement sensor and the paved road surface in the step, and a distance between the set displacement sensor and the paved road surface measured by one of the pair of set displacement sensors. When d2 is d3 and the distance between the set displacement sensor and the pavement road surface measured by the other set displacement sensor is d3, the following equation is expressed by d2- (d2-d3) / 2. Deflection measurement method of pavement surface, characterized in that it comprises a reference distance calibration step of calibrating said reference distance in length as.

  According to the present invention, there are provided a pavement surface deflection measuring machine and a pavement surface deflection measuring method capable of solving the above-described problems and easily and efficiently accurately evaluating the soundness of the pavement surface. be able to.

FIG. 1 is an explanatory diagram showing an outline of the measurement principle of the deflection amount. FIG. 2A is a schematic diagram showing an outline of a deflection measuring machine. FIG. 2B is a schematic diagram showing an arrangement state of each displacement sensor. It is a schematic diagram which shows the state in which the sensor mount was inclined. It is a block diagram which shows an example of the data processing in a deflection measuring method. It is a figure which shows the example of a bending condition and its measurement result. It is a perspective view of the deflection measuring machine which concerns on one Embodiment of this invention. It is the sectional view on the AA line in FIG. 6 in the state attached to the vehicle. It is a figure which shows the result of having measured the deflection.

The pavement surface deflection measuring device according to the present invention is a sensor support unit that supports a deflection measurement displacement sensor that is disposed at an axle position of the vehicle in the traveling direction of the vehicle and measures a distance between the traveling direction and the pavement surface orthogonal to the traveling direction. And a bearing portion that is mounted on the axle and that can support the sensor support portion in a non-rotating state with respect to the rotation of the axle.
Further, the method for measuring the deflection of the paved road surface according to the present invention is a method for measuring the deflection of the paved road surface using a deflection measuring machine of the paved road surface, wherein the deflection measuring sensor is measured by the deflection measuring sensor- According to the method of measuring the amount of deflection of the paved road surface from the difference between the distance between the paved road surface and the reference distance.
As described above, according to the deflection measurement according to the present invention, since the deflection measuring machine is directly attached to the axle of the vehicle, the vibration caused by the unevenness of the paved road surface without being indirectly influenced by the suspension or the like. The deflection of the paved road surface can be measured in a state that directly includes the influence of the above. Therefore, regular vibration noise due to the unevenness of the paved road surface is uniformly included in the measurement result, and it is possible to simplify the removal of the vibration noise from the measurement result.

(Measurement principle)
The principle of measuring the amount of deflection of the paved road surface by the method of measuring the deflection of the paved road surface will be described with reference to FIG. FIG. 1 is an explanatory diagram showing an outline of the measurement principle of the deflection amount.
In FIG. 1, it is assumed that the vehicle travels at a speed v in the x-axis direction. Considering an ideal situation where there is no unevenness or inclination on the paved road surface, and there is no vibration or inclination of the vehicle body itself, the deflection just below the axle is given by the following equation (1). Note that R in FIG. 1 indicates the radius of the wheel.

In the formula (1), w ₀ represents the deflection of the paved road surface under the axle (x = 0) when the vehicle body is loaded with weight, and Δ ₀ is the x when the vehicle body is loaded with weight. A displacement sensor position in the y-axis direction orthogonal to the axis—a distance between the pavement road surface and Δ _d indicates the displacement in the y-axis direction at a position away from the axle position in the x-axis direction (x = d). Sensor position-indicates the distance between the paved road surface.
Δ _d indicates a reference distance in the deflection measurement, and the deflection amount w ₀ is measured by taking a difference from the distance Δ ₀ including the deflection amount of the paved road surface caused by the weight load. Can do.

A pavement surface deflection measuring machine according to an embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 2A, the deflection measuring device 1 is attached to the rear wheel 110 of the vehicle 100. FIG. 2A is a schematic diagram showing an outline of a deflection measuring machine.
In this deflection measuring machine 1, as shown in FIG. 2B, the displacement sensors D1 to D7 are supported by a sensor base so as to be arranged in parallel in the traveling direction of the vehicle 100. As this displacement sensor, a known laser type or radar type displacement sensor can be applied. For example, a known laser displacement meter can be suitably used. FIG. 2B is a schematic diagram showing the arrangement of each displacement sensor.

  Here, the displacement sensor D1 is disposed at the axle position of the rear wheel 110 in the traveling direction of the vehicle 100, and measures the distance between the traveling direction and the paved road surface orthogonal to the traveling direction (hereinafter sometimes abbreviated as the first distance). The present invention relates to the deflection measuring sensor.

Further, the displacement sensor D2 relates to a displacement sensor disposed at a position away from the displacement sensor D1 by a predetermined distance in the traveling direction with respect to a radius R of a wheel attached to the axle.
The displacement sensor D2 has a role of measuring the reference distance, and the lower limit of the distance away from the displacement sensor D1 is preferably 0.4R or more, and more preferably 2R or more.
When the lower limit is less than 0.4R, the difference between the first distance and the reference distance measured by the displacement sensor D2 is small, and a significant deflection measurement may not be performed.
If the lower limit is set to 2R or more, the reference distance is the distance between the displacement sensor and the pavement surface at a sufficiently separated position where there is no deflection due to the load applied to the wheel or the deflection is negligible. The absolute deflection amount of the paved road surface can be measured by taking the difference between the first distance and the reference distance.

On the other hand, the upper limit of the distance of the displacement sensor D2 from the displacement sensor D1 is preferably 5R or less, and more preferably 4R or less.
When the upper limit exceeds 5R, the length of the sensor mount on which the displacement sensor D2 is installed becomes long, and the reference distance may not be correctly measured due to deflection due to the weight of the sensor mount. In addition, regarding the upper limit, in order to eliminate the influence of deflection caused by a load received from a wheel (for example, the front wheel) different from the wheel (for example, the rear wheel) to which the deflection measuring device 1 is attached, the distance between the front wheel and the rear wheel is further reduced. It is preferable that it is 1/2 or less.

In the present embodiment, the reference distance is measured by the displacement sensor D2. As described above, if the reference distance is measured by the displacement sensor arranged in the sensor mount, it can be accurately measured according to the state of the paved road surface, and the deflection measurement can be easily performed. it can.
However, the reference distance does not necessarily need to be measured by the displacement sensor D2, and may be any distance as long as the deflection amount can be evaluated as a difference from the distance between the displacement sensor D1 and the pavement surface. For example, the vehicle may be stopped on a steel plate or the like, and the distance between the displacement sensor D1 and the steel plate measured in a state where there is no deflection by the displacement sensor D1 may be used as the reference distance. Further, another displacement sensor is attached to a position sufficiently separated from the displacement sensor D1 in the traveling direction (for example, the vehicle body middle portion between the front wheel and the rear wheel), and the vehicle is stationary and the displacement sensor is placed between the paved road surface. A distance may be measured, and this may be used as the reference distance.

By the way, when the vehicle travels, the sensor mount vibrates in the direction orthogonal to the travel direction (pitch) according to the state of the paved road surface and the rotational movement of the wheels, like the axle, and the travel direction. In addition to vibrating in the left-right direction (rolling), the load on the pavement road surface due to deceleration and acceleration of the vehicle and the twisted state of the axle due to the bending motion of the vehicle are in a horizontal position relative to the pavement road surface Inclined and fluctuates. For example, if the vehicle being driven is decelerated, the center of gravity shifts to the front of the vehicle, the sensor mount tilts downward in the direction of travel, and if the vehicle is accelerated, the center of gravity is Shifting backward, the sensor mount tilts to the right with respect to the traveling direction.
Therefore, since the reference distance based on the measurement of the displacement sensor D2 always changes during traveling, it is necessary to set the reference distance at a certain time each time. Further, it is necessary to calibrate the reference distance so as to eliminate the influence of the tilt change of the sensor mount from the reference distance measured from the displacement sensor D2.

Therefore, in this embodiment, the displacement sensor D3 is arranged at a position symmetrical to the displacement sensor D2 around the displacement sensor D1 (the deflection measurement displacement sensor) in the traveling direction.
That is, as shown in FIG. 3, the displacement sensors D2 and D3 are a pair of pair displacement sensors, and the pair displacement sensor measured by one of the pair of pair displacement sensors (displacement sensor D2)- When the distance between the paved road surfaces is d2, and the distance between the set displacement sensor and the paved road surface measured by the other set displacement sensor (displacement sensor D3) is d3, the following equation is given: d2- (d2-d3) ) / 2 is the influence of the tilt variation of the sensor mount, and the reference distance is calibrated with this length.
Therefore, the deflection w _{0 in} this case is expressed as follows: w ₀ = d 1 − {d 2 − (d 2 −d ₃ ), where d 1 is the distance between the displacement sensor D 1 measured by the displacement sensor D 1 and the pavement surface (the first distance). / 2}.

  Further, when the vehicle is stopped, the deflection of the paved road surface is axisymmetric with respect to a vertical axis passing through the axle, and the maximum deflection occurs immediately below the axle. On the other hand, when the vehicle is traveling, the maximum deflection position differs depending on the traveling speed of the vehicle, the hardness of the paved road surface, and the type of paving, but is usually not directly below the axle but with respect to the vertical axis. It occurs on the rear side of the vehicle. Further, the occurrence of deflection differs between the front side and the rear side of the vehicle with respect to the vertical axis, and is asymmetric.

Therefore, in order to estimate the maximum deflection position, in this embodiment, displacement sensors D4 to D7 are arranged as the deflection state measurement displacement sensors, and the deflection amount at the maximum deflection position is measured.
That is, as shown in FIG. 5, on the coordinate axis, an approximate straight line (or approximate curve) based on the measurement results of the displacement sensors D2, D4, D5 and an approximate straight line (or approximation based on the measurement results of the displacement sensors D3, D6, D7). Curve), the intersection of these approximate straight lines (or approximate curves) is estimated as the maximum deflection position, and the distance between the displacement sensor D1 and the pavement surface (the first) is the distance from the displacement sensor D1 to the maximum deflection position. 1 distance) is corrected, and the amount of deflection at the maximum deflection position is measured.

The approximate straight line can be obtained by arranging at least two deflection state displacement measurement sensors at front and rear positions in the traveling direction around the deflection measurement displacement sensor (displacement sensor D1).
Further, the deflection state measurement displacement sensor is preferably arranged at a position away from the deflection measurement displacement sensor by a distance of less than 1R with respect to the radius R of the wheel in the traveling direction. If it is arranged at a position of 1R or more, the measurement is performed at a position where there is little deflection, and it may be difficult to estimate the maximum deflection position using the approximate straight line (or the approximate curve).
If the distance is less than 1R, the combined displacement sensor (displacement sensors D2 and D3) can also function as the deflection state measurement displacement sensor.

When estimating the maximum deflection position by the approximate curve, by arranging the deflection state measurement displacement sensor densely, for example, a downwardly convex high-order function corresponding to the deflection shape of the paved road surface on the coordinate axis Alternatively, an approximate curve by a special function may be calculated, and a more accurate maximum deflection position may be estimated from position information at the bottom.
Further, by disposing the deflection state measurement displacement sensor at a symmetrical position with the deflection measurement displacement sensor (displacement sensor D1) as the center in the traveling direction, a more accurate maximum deflection position can be estimated.
When there is a significant deflection at a position of 1R or more depending on the magnitude of the load applied from the wheel, the deflection state measurement at a position of less than 1R is performed from the viewpoint of obtaining a highly accurate approximate curve. In addition to the sensor, the deflection state measuring sensor can be arranged at a position of 1R or more. However, also in this case, from the viewpoint of correctly estimating the maximum deflection position, it is preferable to arrange at least two deflection state measurement sensors at positions less than 1R at the front and rear positions in the traveling direction.

  In the deflection measurement according to the present invention, the vehicle 100 is provided with a distance measuring device 90 such as a rotary encoder (see FIG. 2A) to synchronize the measurement of the deflection and the position information where the deflection has occurred. It is possible to obtain deflection information on the paved road surface.

By simultaneously measuring the deflection amount and position information of the paved road surface at regular time intervals, deflection information corresponding to the measurement position can be obtained. Here, the deflection information includes stationary noise, but according to the deflection measuring method using the deflection measuring apparatus of the present invention, the stationary noise can be removed.
That is, the stationary noise can be limited to regular vibration noise associated with vibration of the axle or rotational movement of the vehicle since the deflection measuring machine is supported on the axle. Can be removed by averaging over some appropriate interval.
For example, the deflection amount measurement results at a plurality of points obtained at a constant sampling frequency are averaged at intervals of a traveling distance of 10 m, and one average value representing the interval is obtained. At this time, the vibration noise is included so as to increase or decrease the amount of deflection. However, since the vibration noise is uniformly present in the deflection amount measurement results of the plurality of points as the regular noise, the section average is taken. Thus, the increase / decrease is canceled and the vibration noise can be removed.

An example of information processing by the deflection measuring method of the present invention is shown in FIG. FIG. 4 is a block diagram illustrating an example of data processing in the deflection measurement method.
First, the deflection data and position data of the paved road surface are synchronized as time series data and acquired as deflection data for each measurement position.
A plurality of the deflection data are acquired at a constant sampling frequency. For the plurality of deflection amount data, a section average is calculated in a specific section, and a section average value in the section is calculated. This section average value is calculated for distance information measured by each displacement sensor. This section average value is calculated with, for example, coordinate axes as shown in FIG. FIG. 5 is a diagram illustrating an example of the deflection state and the measurement result.
The reference distance (reference position) is set based on the displacement sensor D2 that is the pair of paired displacement sensors. At this time, based on the measurement result of the displacement sensor D3, the reference distance may be calibrated with a length represented by d2- (d2-d3) / 2 so as to eliminate the influence of the tilt variation of the sensor mount. it can.
The difference between the reference distance and the section average value of the displacement sensor D1 is calculated, and w ₀ = d1− {d2− (d2−d3) / 2} is calculated, and the amount of deflection w ₀ of the paved road surface in a specific section is calculated. .
At this time, even if the maximum deflection position is estimated based on each section average value obtained from the displacement sensors D2 to D7, and the section average value obtained from the displacement sensor D1 is corrected by the deflection amount at the maximum deflection position. Good. The data processing can be executed by an electronic computer or the like.
As described above, the amount of deflection of the paved road surface can be measured.

Next, a specific configuration of the deflection measuring machine 1 in which each displacement sensor is arranged as described above and a state of attachment to the vehicle 100 will be described with reference to FIGS. 6 and 7.
FIG. 6 is a perspective view of a deflection measuring machine according to an embodiment of the present invention. FIG. 7 is a cross-sectional view taken along line AA in FIG. 6 in a state of being attached to the vehicle.

  As shown in FIG. 6, the deflection measuring machine 1 includes a hanger frame 20 as a sensor support portion, a frame base 30, a sensor mount 40, hanger portions 50A and 50B, and a bearing housing 10 as a bearing portion.

  The hanger frame 20 is supported by the bearing housing 10 and extends in a plate-like first frame portion 20A vertically suspended from the top of the first frame portion 20A with a substantially L-shape bent in the wheel direction from the top. And a plate-like second frame portion 20B.

  The frame base 30 is supported on the bottom side of the first frame portion 20B, and is configured as a rectangular frame base that is installed in a horizontal state and two sides parallel to the traveling direction X at the outer peripheral position of the wheel. Is done. By disposing such a frame 30, it is possible to suppress the pitching and rolling of the sensor mount 40 during traveling.

The sensor mount 40 is configured as a long plate-like member that is arranged so as to bridge over the other two sides orthogonal to the traveling direction X of the frame 30, and each of the displacement sensors D1 to D7 is arranged at a predetermined position of the trunk portion. Is done.
Here, in this embodiment, in order to perform the deflection measurement at the intermediate position of the W tire where the load load on the paved road surface by the vehicle is the largest, the sensor frame 40 is orthogonal to the traveling direction X on the frame base 30. These are arranged so as to bridge between the substantially middle positions of the two sides. However, there is no particular limitation, and the sensor mount 40 may be extended to another position, or one side arranged in parallel with the traveling direction X of the frame base 30 may be configured as the sensor mount.
The length of the sensor base 40 in the running direction X is preferably too long to provide the displacement sensors D1 to D7, because if the length is too long, deflection due to its own weight occurs. The size of the frame 30 is set according to the length of the frame.

The hanger part 50 </ b> A is suspended and supported by the hanger frame 20, and is configured to suspend the frame 30 at positions on both ends of the sensor mount 40 on the suspended end side. By arranging the hanger portion 50 </ b> A in this way, it is possible to reduce the deflection due to the weight of the sensor mount 40 indirectly through the suspension of the frame base 30.
Similarly, the hanger portion 50B is also supported by being suspended from the hanger frame 20, and is configured to suspend the frame base 30 on the suspended end side. The hanger part 50B can support the first frame part 20A and the hanger part 50A stably by arranging the frame base 30 and reduce the distortion due to the influence of the frame base 30 during traveling and the deflection due to its own weight. it can.

  The first frame 20A and the hangers 50A and 50B are attached to the frame base 30, although not particularly shown, the height position can be adjusted by allowing the fastening position of the fastening part to slide in the height direction. It is preferable that By having such height adjusting means, the deflection measuring device 1 can be appropriately installed even for tires having different diameters.

  In addition, the hanger frame 20, the frame base 30, the sensor base 40, and the hanger portions 50A and 50B may be formed of a highly rigid material such as a stainless steel material in order to reduce distortion due to influence during traveling and deflection due to its own weight. preferable.

  As shown in FIG. 7, the bearing housing 10 includes a housing portion 11 that can be fixed to an axle 82, a bearing 12, and a fixed shaft 13. The fixed shaft 13 is brought into a non-rotating state with respect to the rotational movement of the axle 82, and the sensor support portion is made to rotate on the axle 82 by engaging the fixed shaft 13 with the first frame portion of the hanger frame 20. On the other hand, it is supported in a non-rotating state.

By the way, the deflection measuring machine 1 is configured to be supported by the axle support member 81 on the vehicle side in addition to the support by the axle 82 because the stability in the tilt direction of the sensor mount 40 may be insufficient. It is preferable.
Therefore, in the second frame portion 20 </ b> B, the extended end side that is extended by being bent substantially L-shaped in the wheel direction is further bent to form the support portion 21 and supported by the axle support member 81. Thereby, in combination with the support by the axle 82, the deflection measuring device 1 can be stably attached to the vehicle. Alternatively, the inner ring-side frame base 30 may be locked to and supported by the axle support member 81.
The axle support member 81 differs depending on the type of vehicle, but as a member that is directly supported by the axle 82, a member that is not affected by suspension vibration or vehicle body vibration other than the axle 82 is applicable. Examples include a leaf spring and a bracket for attaching an air suspension.
In addition, the code | symbol 80A-80D in FIG. 7 shows a tire, and the code | symbol 83 shows an axle head.

In this embodiment, although it was set as the structure attached to the vehicle of a W tire, as a structure attached to the vehicle of a single tire by changing suitably the magnitude | size of the frame 30 and the structure of the sensor mount 40 and hanger part 50A, 50B. Good. In addition, although the tilt variation of the sensor mount 40 is measured by the displacement sensors D2 and D3, the tilt variation may be measured by a gyro sensor. Alternatively, by arranging an acceleration sensor (not shown), the acceleration generated in the sensor mount 40 is measured, the second order integration is performed, the displacement amount is calculated, and the displacement of the sensor mount 40 is reduced from the record of the displacement sensor. It is also possible to remove the influence of the tilt variation of the sensor mount 40.
In addition, this embodiment shows an example of embodiment of this invention, and the technical idea of this invention is not limited to this embodiment.

In the deflection measuring device 1 according to the first embodiment described above, a deflection measuring device provided with displacement sensors D1 to D3 as displacement sensors was attached to the rear wheel of the vehicle, and the deflection of the paved road surface was measured.
Here, regarding the arrangement of the displacement sensors D1 to D3, S1 and S1 ′ are 450 mm in FIG. The radius R of the rear wheel is 500 mm.
As the pavement surface, the test runway installed on the premises of the National Institute of Advanced Industrial Science and Technology and the Public Works Research Institute was measured.
In addition, as a load that affects the magnitude of deflection, 98 kN is applied as a rear wheel axle load, the vehicle traveling speed is 60 km / h, and the sampling frequency of displacement data is 2,000 Hz.
Under the above conditions, the deflection of the paved road surface according to the example was measured.

  On the other hand, as a comparative example, the paved road surface was measured under the same conditions as in the example except that the sensor support portion to which the displacement sensors D1 to D3 were attached was attached to the body on the side surface of the vehicle body.

The results of measuring the deflection with these systems are shown in FIG. As can be understood from FIG. 8, in the comparative example, there is a difference in displacement depending on the measurement position, and the center of displacement is also different. In addition, a long displacement waveform with a large displacement is observed.
On the other hand, in the embodiment, although there is a difference in displacement depending on the measurement position, the displacement is based on the vicinity of 0 mm displacement at any position. Further, the period of the displacement waveform is substantially constant, and a displacement waveform having a long period is not observed.
From such a result, in an Example, it can be evaluated that the vibration noise based on the unevenness | corrugation of the said pavement road surface can be reduced with respect to a comparative example.
Therefore, in the deflection measurement according to the present invention, the soundness of the paved road surface can be accurately evaluated simply and efficiently.

DESCRIPTION OF SYMBOLS 1 Deflection measuring machine 10 Bearing housing 11 Housing part 12 Bearing 13 Fixed shaft 20 Hanger frame 20A 1st frame part 20B 2nd frame part 21 Support part 30 Frame base 40 Sensor mount 50A, 50B Hanger part 80A-80D Tire 81 Axle support member 82 Axle 83 Axle head 90 Distance measuring device 100 Vehicle 110 Rear wheel D1 to D7 Displacement sensor X Traveling direction

Claims (5)

A sensor support that supports a deflection measurement displacement sensor that is disposed at an axle position of the vehicle in a traveling direction of the vehicle and that measures a distance between the traveling direction and a pavement surface orthogonal to the traveling direction;
A bearing that is mounted on the axle and that can support the sensor support in a non-rotating state with respect to rotation of the axle;
Have a, a sensor mount to the sensor support is extended in the running direction of the vehicle,
Further, at least two each of the front and rear positions in the traveling direction around the deflection measurement displacement sensor and at a distance from the deflection measurement displacement sensor by a distance of less than 1R with respect to the radius R of the wheel. the traveling direction and the distance deflected state measuring displacement sensor for measuring the said pavement surface in the perpendicular direction is disposed deflection measuring machine pavement surface, characterized in Rukoto.   The sensor support has a sensor frame extending in the traveling direction of the vehicle, and is a symmetric position about the deflection measuring displacement sensor and the deflection measuring displacement sensor in the traveling direction with respect to the sensor frame; And a pair of pairs for measuring the distance between the traveling direction and the pavement surface orthogonal to the direction of travel at a position separated from the deflection measurement displacement sensor by a distance of 0.4R to 5R with respect to the radius R of the wheel attached to the axle. The pavement surface deflection measuring machine according to claim 1, wherein a displacement sensor is arranged.   A sensor support part is supported by a bearing part and extends in a plate-like first frame part vertically suspended from the top part of the first frame part so as to be bent substantially L-shaped in the wheel direction. A hanger frame having a plate-like second frame part;
  A rectangular frame that is supported on the bottom side of the first frame part, is horizontally installed at the outer peripheral position of the wheel, and two sides are installed in parallel with the traveling direction;
  A sensor base that is one of the two sides of the frame base, or a long plate-like member that is arranged to bridge over the other two sides orthogonal to the traveling direction of the frame base;
  A hanger part that is supported by being suspended from the hanger frame and that suspends the frame base at the positions of both ends of the sensor frame on the suspension end side thereof,
  The pavement surface deflection measuring apparatus according to claim 1, comprising:   A method for measuring the deflection of the pavement surface using the pavement surface deflection measuring device according to claim 1,
  A difference calculating step for calculating a difference between a reference distance and a distance between the deflection measurement sensor and the paved road surface measured by a deflection measurement sensor;
  The maximum deflection position of the paved road surface is estimated from each deflection state measurement displacement sensor, and the distance between the deflection measurement sensor and the paved road surface is corrected to the distance between the deflection measurement sensor and the paved road surface at the maximum deflection position. A maximum deflection correction step,
  A method for measuring the deflection of a paved road surface, comprising:   A method for measuring the deflection of the pavement surface using the pavement surface deflection measuring device according to claim 2,
  A difference calculating step for calculating a difference between a reference distance and a distance between the deflection measurement sensor and the paved road surface measured by a deflection measurement sensor;
  The maximum deflection position of the paved road surface is estimated from each deflection state measurement displacement sensor, and the distance between the deflection measurement sensor and the paved road surface is corrected to the distance between the deflection measurement sensor and the paved road surface at the maximum deflection position. A maximum deflection correction step,
  Of the pair of pair displacement sensors, the distance between the pair displacement sensor measured by one of the pair displacement sensors and the pavement surface is d2, and the pair displacement sensor measured by the other pair displacement sensor is the pavement surface. A reference distance calibration step for calibrating the reference distance with a length represented by the following formula: d2- (d2-d3) / 2, where d3 is a distance between
  A method for measuring the deflection of a paved road surface, comprising: