JP4615271B2 - Road surface profile measurement method - Google Patents

Description

The present invention relates to a method for measuring a road surface cross-sectional profile for measuring an uneven state of a flat surface having unevenness such as a road surface of a road.

Conventionally, as a method for measuring a road surface profile, for example, as shown in Patent Document 1, a disk-shaped first roller, a second roller, and a rotation direction aligned with the same straight line at a predetermined interval on the same straight line. A first connecting rod, which is provided with a third roller and is attached to each rotary shaft of the first and second rollers and rotatably connects the first and second rollers, and each rotary shaft of the second and third rollers A second connecting rod which is rotatably attached to the second and third rollers, distance measuring means for measuring the moving distance of the roller, and the first connecting rod and the second connecting rod are rotated from a straight state. There is known one using a measurement block provided with angle detection means for detecting a connection angle which is a displacement angle when moved.
Japanese Patent No. 3292200

In this measurement method, the measurement block is elastically attached to the measurement vehicle so as to be urged toward the road surface by the connecting member, and the first and third rollers are in the center with the first and second connecting rods in a straight state. Every time the leading roller in the direction of travel reaches the measurement position sequentially when the measurement block passes the reference distance in the vertical direction of the road surface, the measurement distance is determined by dividing the reference distance into a plurality of points with the inter-space dimension as the reference distance. The connecting angle formed by the first and second connecting rods at each measurement position is detected by the angle detecting means. Based on the connection angle detection value by this angle detection means and the known height data at each measurement position in the measurement block when the measurement block is at the previous measurement position, the filter calculation method is used to A unit road surface profile of the reference distance is obtained by calculating road height data. As an example of the filter calculation method, in particular, according to a method using an infinite impulse response filter (hereinafter referred to as IIR filter), the road surface is measured at each short pitch between the measurement positions divided within the reference distance. Since accurate unevenness data can be obtained quickly, unevenness on the entire road surface, including small unevennesses such as structure joints, concrete mages, potholes, etc., existing on the entire road surface can be detected and obtained accurately. The road profile can be used for road step management.

However, in the road surface profile measurement method described above, it is necessary that the fixed lengths at both ends of the measurement road surface be flat when performing the arithmetic processing, the profile measurement work is complicated, and the profiles at both ends are There was a problem that it could not be measured. Therefore, an extra measure of flattening both ends of the road surface to be measured is often required, and the profile measurement work has become more complicated.

SUMMARY OF THE INVENTION The present invention is intended to solve the above-described problem, and a road surface profile profile measuring method that enables simple and accurate profile measurement over the entire range of the measurement road surface even if the fixed length of both ends of the measurement road surface is not flat. The purpose is to provide.

In order to achieve the above object, the structural feature of the invention of claim 1 is that the disc-shaped first roller, the second roller, and the rotation direction are aligned on the same straight line with a predetermined interval. A first connecting rod, which is provided with a third roller and is attached to each rotary shaft of the first and second rollers and rotatably connects the first and second rollers, and each rotary shaft of the second and third rollers A second connecting rod having a different length from the first connecting rod which is rotatably attached to the second and third rollers, distance measuring means for measuring the moving distance of the roller, the first connecting rod and the second Using a measuring block provided with an angle detecting means for detecting a connecting angle, which is a displacement angle when the connecting rods are rotated from a straight state, and moving the measuring block on the road in a predetermined direction, the unevenness of the road surface Method for measuring road profile to measure conditions Therefore, for each road to be measured, a plurality of measurement positions are determined for each predetermined distance, and each time the measurement block runs on the road surface and the first roller in the direction of travel reaches the measurement position sequentially, Then, the connecting angle formed by the first and second connecting rods is detected by the angle detecting means and obtained as a detected connecting angle, the road surface profile is estimated based on the detected connecting angle, and the suitability of the estimated profile is evaluated. An evaluation function is set, and the profile that minimizes the evaluation function is set as a measurement profile , and the evaluation function is estimated with respect to the sum of squares of the difference between the connection angle data calculated from the estimated profile and the connection angle detection value. The sum of the squares of the slopes of the profile is multiplied by a small predetermined coefficient .

In the invention of claim 1 configured as described above, the measurement block starts from the starting point, travels in a predetermined direction on the road surface, and each time the leading roller sequentially reaches each predetermined measurement position, The connection angle formed by the first connecting rod and the second connecting rod is detected by the angle detecting means at the measurement position. A road surface profile is estimated based on the detected connection angle by the angle detection means. Therefore, even if the fixed length at both ends of the measurement road surface is not flat, an error does not occur in the connection angle detection value. Furthermore, by setting an evaluation function that evaluates the profile of the road surface and minimizing this evaluation function using a calculation method such as the conjugate gradient method, the measurement road surface can be measured even if the fixed length at both ends of the measurement road surface is not flat. The cross-sectional profile of the road surface can be obtained easily and accurately over the entire range.

A method for calculating a cross-sectional profile of the road surface using the conjugate gradient method for this evaluation function will be described. This calculation method is to obtain a profile y that minimizes the evaluation function f (y). First, the setting of the evaluation function f (y) will be described below.

As shown in FIG. 3, in the measurement block 10, the first roller and the second roller are connected by a first connecting rod having a length L ₁ [mm], and the second roller and the third roller have a length L _2. It is connected with a second connecting rod of [mm] (<L ₁ ). The measurement of the connection angle and the estimation of the profile are performed for each step with 10 [mm] as one step. Third roller proceeds i step from the origin, when the height is in the y (i), the position of the second roller and the first roller, each _{i-L 2/10, i-} (L 1 + L 2) / 10 Step in there, the height of the road surface is _{y (i-L 2/10} ), in _{y (i- (L 1 + L} 2) / 10). From the state of these three rollers, the angle u (i) formed by the first connecting rod 14 and the second connecting rod 15 is expressed by the following equation (1). Furthermore, when the number 1 is arranged, the following number 2 is obtained.

Further, when the above formula 1 is collected from 1 to n steps, the following formula 3 is obtained. In Equation 3, M becomes Equation 4.

If the evaluation function f (y) is set to the following Expression 5 in order to obtain the solution y of Expression 3, the value of y that minimizes the evaluation function f (y) satisfies the linear equation of Expression 3. Therefore, by solving the equation 3 with optimized by the conjugate gradient method, the connecting angle u = obtained from measurement block (u (1), u ( 2), ..., u (n)) T or al, road height is _{y = (y (1- (L} 1 + L 2) / 10), ..., y (0), y (1), ..., y (n)) can be obtained a profile of ^T.

However, in the case of Equation 5, since the number of simultaneous equations is n and the number of unknown y is n + (L ₁ + L ₂ ) / 10 , there is a possibility that various solutions are calculated. is there. Therefore, it is considered that n + (L ₁ + L ₂ ) / 10 unknowns are obtained from n simultaneous equations by adding the following equation 6 to equation 5. This makes it possible to calculate the smoothest candidate solution (profile). Here, Expression 6 can be expressed as Expression 7 by a matrix and a vector, and D in Expression 7 is expressed by Expression 8. Note that ε in Equation 6 is a very small number.

As described above, the evaluation function f (y) in the present invention is finally revised as shown in the following equation 9, and the gradient ∇f (y) of this evaluation function f (y) is as shown in the following equation 10. Become. An arithmetic method for obtaining y that minimizes Equation 9 representing the evaluation function f (y) by the conjugate gradient method will be described below using a “conjugate gradient method arithmetic program” shown in FIG.

First, initialization is performed in step S31, an appropriate initial point y ⁽⁰⁾ is selected, and k = 0 is set. Next, as the calculation of the steepest descent direction, the gradient of the evaluation function is calculated based on the above formula 9, and y is set to formula 11 as the component y ^(k) for each measurement position (S32).

Next, a straight line search is performed, and α ^(k) satisfying the following formula 12 is obtained (S33). Here, α ^(k) is based on the Fletcher-Reeves formula, as shown in Equation 13.

Next, y ^{(k + 1)} shown in the following equation 14 is calculated (S34).

Next, it is determined whether or not d ^(k) = 0 (S35). If d ^(k) = 0 is not satisfied, the program proceeds to step S36, and the search direction is calculated according to the following equation ⁽ 15). Here, β ^(k) is a formula of Fletcher-Reeves as shown in the following equation ⁽ 16).

Subsequently, after k is incremented by “1”, the program is returned to step S33, and the arithmetic processing of steps S33 to S37 is repeated. When d ^(k) = 0, the optimum y is obtained, the program is moved to step S38, and the execution of the program is terminated. Thereby, the cross-sectional profile of the road surface is obtained with high accuracy.

In the present invention, the measurement block is elastically attached to the measurement vehicle so as to be biased toward the road surface by the connecting member, and the profile in the vertical direction of the road surface is measured by moving the measurement vehicle on the road in a predetermined direction. can do. In this way, by attaching the measurement block to the measurement vehicle, a cross-sectional profile of a particularly long distance road surface can be obtained stably and easily.

In the present invention, there is no error in the profile even if the fixed length at both ends of the measurement road surface is not flat. Therefore, an evaluation function for evaluating the road surface profile is set, and this evaluation function is used as a conjugate gradient method or the like. By minimizing using this calculation method, a cross-sectional profile of the road surface can be obtained easily and accurately over the entire range of the measurement road surface even if the fixed length at both ends of the measurement road surface is not flat. As a result, according to the present embodiment, since it is possible to obtain accurate unevenness data of the road surface for each short pitch between each measurement position divided on the road surface, the structure joint, concrete squeeze, pot existing on the entire road surface Irregularities on the entire road surface including small irregularities such as holes can be detected with high accuracy. Furthermore, the cross-sectional profile of the road surface thus obtained can be used for road level difference management.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. 1 and 2 are a front view and a plan view showing a schematic configuration of a measurement block 10 used in the method for measuring a profile in a longitudinal direction of a road surface D of a road according to the embodiment. Note that the longitudinal profile measurement position of the road D is performed with respect to the passing position of the left wheel of the vehicle, which is called the out-wheel path (OWP) where the road surface is most worn. It has become clear that the out-wheel path of this road is the position through which 70-80% of the vehicle passes.

As shown in FIG. 1, the measurement block 10 has three disc-shaped first, second, and third rollers 11, 12, and 13 in the rear, middle, and front in the direction of travel. Each of the rollers 11, 12, and 13 is made of hard rubber or plastic, and is arranged on the same straight line with the rotation direction aligned with the same straight line direction. The outer diameters of the first, second, and third rollers 11, 12, and 13 are 100 mmφ in this embodiment. Rotating shafts 11a, 12a, and 13a are fixed to the first, second, and third rollers 11, 12, and 13, respectively. A pair of long plate-like first connecting rods 14 are fixed to both ends of the rotation shafts 11a and 12a of the first roller 11 and the second roller 12 so that the rotation shafts 11a and 12a are rotatable. A pair of second connecting rods 15 having a long plate shape and different length from the first connecting rod 14 are provided at both ends of the rotating shafts 12a and 13a of the second roller 12 and the third roller 13, respectively. 13a is fixed so as to be rotatable. In this embodiment, the length of the first connecting rod 14 is 250 mm, and the length of the second connecting rod 15 is 230 mm.

A distance measuring device 16 is attached to the first connecting rod 14 (or the second connecting rod 15) to detect the moving distance of the measurement block from the number of rotations of any of the rollers 11, 12, and 13. Further, the second connecting rod 15 (or the first connecting rod 14) is a rotary that is an angle detecting means for detecting a connecting angle θ that the first connecting rod 14 and the second connecting rod 15 are rotated from a straight state. An encoder 18 is attached.

The measurement block 10 is connected to a measurement wheel 20 by a connection support bar 19 at a first connection bar 14. The connection support bar 19 is rotatably attached to the first connection bar 14 and the measurement wheel 20. Further, the connecting support bar 19 is elastically connected to the measuring wheel 20 by a coil spring 19a at an intermediate position in the longitudinal direction, and is biased by the coil spring 19a so as to slightly press the measuring block 10 against the road. . As a result, the measurement block 10 can move while being pressed lightly against the road surface as the measurement wheel 20 moves.

The measuring wheel 20 is provided with a control device 21 composed of a computer. The control device 21 executes a “conjugate gradient method calculation program” stored in the storage unit. The storage unit of the control device 21 stores a measurement position interval value (measurement pitch) of 10 mm, and stores the arithmetic expressions of the above formulas 9 to 15. The distance measuring device 16 and the rotary encoder 18 are connected to the input side of the control device 21, and an output device such as a printer (not shown) is connected to the output side.

Next, the measurement of road irregularities by the measurement system will be described. By moving the measurement wheel 20 forward (in the vertical direction), the measurement block 10 also moves. When the measurement block 10 moves 10 mm and reaches the first measurement position, the measurement results of the distance measuring device 16 and the rotary encoder 18 are input to the control device 21. That is, first, the value of the connection angle u (10) at the first measurement position is obtained. Thereafter, every time the measurement block 10 moves 10 mm, the controller 21 sequentially obtains connection angle data u (20), u (30),... At each measurement position.

That is, each time the measurement block 10 starts from the starting point G and proceeds in the longitudinal direction of the road surface, and the leading third roller 13 sequentially reaches each measurement position, the first and second connecting rods at each measurement position. The connection angle formed by 14 and 15 is detected by the rotary encoder 18. In response to the output from the distance measuring device 16 and the connection angle detection value u (i) from the rotary encoder 18, the control device 21 evaluates by executing the “conjugate gradient method calculation program” as described above. By minimizing the function and obtaining y at that time, a precise longitudinal profile of the entire road surface can be obtained.

  For this reason, in this embodiment, there is no error in the profile even if the fixed length at both ends of the measurement road surface is not flat. An evaluation function for evaluating the road surface profile is set, and this evaluation function is used as a conjugate gradient method. By minimizing using a calculation method such as the above, a longitudinal profile of the road surface can be obtained easily and accurately over the entire range of the measurement road surface even if the fixed length at both ends of the measurement road surface is not flat. As a result, according to the present embodiment, since it is possible to obtain accurate unevenness data of the road surface for each short pitch between each measurement position divided on the road surface, the structure joint, concrete squeeze, pot existing on the entire road surface Irregularities on the entire road surface including small irregularities such as holes can be detected with high accuracy. Furthermore, the road surface profile thus obtained can be used for road level difference management.

Next, specific measurement results of the above-described embodiment will be described. Measurement is performed on a road surface having a length of 100 m using five measurement blocks 10, and calculation is performed for the above-described embodiment and the conventional IIR method. Processing was performed, and each calculation result (1), (2), (3), (5), (6) was compared with data (4) obtained by leveling. Of the results, (1) to (3) of the example and the conventional example are shown in FIGS . Regarding the measurement results other than (1) to (3), (5) ofs-278.110, RMSE 11.368 in the present example, (6) ofs-279.785, RMSE 12.199, and (5) in the IIR method. ofs-278.110, RMSE20.17, (6) ofs-279.785, RMSE60.325. Ofs is an amount for correcting the data variation due to the concentricity variation of each roller of the measurement block, and RMSE represents the average error of the calculation result for the leveling data.

As a result, in this example, the mean square value RMSE was 12.722, and the RMSE variation σ was 1.917. On the other hand, in the conventional example, the mean square value RMSE was 87.563, and the RMSE variation σ was 53.489. That is, in this example, the mean square value RMSE average was improved to 1 / 6.8 and the RMSE variation σ was improved to 1 / 27.9 compared with the IIR method.

In the above-described embodiment, the profile data is calculated based on the connection angle detection value at the measurement position by the control device 21 mounted on the measurement vehicle 20. Only measurement data may be acquired, and profile data may be calculated at another location based on the measurement data. In the above embodiment, the distance measuring device is not limited to that shown in the above embodiment, and the mounting position is not limited to the connecting rod. Also, the angle detection means is not limited to the rotary encoder, and similar detection means can be used. Furthermore, in the above-described embodiment, the profile of the road profile is obtained. However, the profile is not limited to this, and a cross-sectional profile or a cross-sectional profile of a diagonal pedestrian crossing at a scramble intersection may be obtained.

Further, as a method for setting an evaluation function and its optimization, a combination of the above-mentioned quadratic evaluation function and the conjugate gradient method is preferable. In addition, although the calculation speed is slow, Lagrangian undetermined multiplier method or linear It is also possible to use a programming method. The specific configuration of the measurement block is not limited to that shown in the above embodiment. In addition, what was shown in the said Example is an example, and can be implemented variously in the range which does not deviate from the main point of this invention.

According to the present invention, since it is possible to obtain accurate unevenness data of the road surface for each short pitch between each measurement position divided within the reference distance, a structure joint, a concrete mage, a pothole, etc. existing on the entire road surface The unevenness of the entire road surface including small unevenness can be detected with high accuracy. Furthermore, the road surface profile thus obtained can be used for road level difference management.

It is a front view which shows roughly the measurement block attached to a measurement vehicle in order to measure the flatness of the road surface of the road which is one Example of this invention. It is a top view which shows the same measurement block roughly. It is explanatory drawing explaining the method of measuring the unevenness | corrugation of the road surface in a reference distance with a measurement block. It is a flowchart which shows the "conjugate gradient method calculation program" performed by the control apparatus. It is a graph which shows the calculation result of the longitudinal profile of the road surface calculated using the conjugate gradient method. It is a graph which shows the result of the longitudinal profile of the road surface analyzed using the conventional IIR method.

DESCRIPTION OF SYMBOLS 10 ... Measuring block 11, 12, 13 ... 1st, 2nd, 3rd roller, 11a, 12a, 13a ... Rotating shaft, 14 ... 1st connecting rod, 15 ... 2nd connecting rod, 16 ... Distance measuring device, DESCRIPTION OF SYMBOLS 18 ... Rotary encoder (angle detection means), 19 ... Connection support rod, 20 ... Measuring wheel, 21 ... Control apparatus.

Claims (3)

Disc-shaped first rollers, second rollers, and third rollers are arranged on the same straight line with a predetermined interval and with the rotation direction aligned with the same straight line direction, and the rotation shafts of the first and second rollers are provided on the respective rotation shafts. A first connecting rod that is attached and rotatably connects the first and second rollers, and is attached to the respective rotation shafts of the second and third rollers and rotatably connects the second and third rollers. A second connecting rod having a length different from that of the first connecting rod; distance measuring means for measuring a moving distance of the roller; and when the first connecting rod and the second connecting rod are rotated from a straight state. A measurement method of a road surface cross-sectional profile using a measurement block provided with an angle detection means for detecting a connection angle, which is a displacement angle, and measuring the uneven state of a road surface by moving the measurement block on a road in a predetermined direction. There,
For the road to be measured, determine multiple measurement positions for each prescribed distance,
Each time the measurement block travels on the road surface and the first roller in the traveling direction sequentially reaches the measurement position, the angle detection means detects the connection angle formed by the first and second connection rods at each measurement position. To obtain a connection angle detection value, estimate a road surface profile based on the connection angle detection value, set an evaluation function for evaluating the appropriateness of the estimated profile, and set a profile that minimizes the evaluation function as a measurement profile age,
As the evaluation function, a predetermined small coefficient with respect to the square sum of the slope of the estimated profile with respect to the square sum of the difference between the connection angle data calculated from the estimated profile and the detected connection angle value A method for measuring a road surface profile, characterized in that a product obtained by multiplying the values is added . 2. The road surface profile measuring method according to claim 1 , wherein a conjugate gradient method is used as a method of calculating a profile that minimizes the evaluation function. The measurement block is elastically attached to the measurement vehicle so as to be biased toward the road surface by a connecting member, and the vertical profile of the road surface is measured by moving the measurement vehicle on the road in the vertical direction. The road surface profile profile measuring method according to claim 1 or 2 .

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