JPH03107712A - Road surface measuring method - Google Patents

Abstract

PURPOSE:To take a measurement at high traveling speed, to obtain the rugged profile of the entire road surface to be measured and to improve the reliability by arranging plural sets of road surface measuring means in the width direction of a road while the numbers and positions of noncontact laser displacement gauges are uniformed. CONSTITUTION:Noncontact laser displacement gauges 2, 3, and 3 are arranged on a measuring wheel 1 at mutually different intervals on a straight line in the front-rear direction of the vehicle body to constitute one road surface measuring means S, and plural road surface measuring means S1 - S4 are arranged based upon the one road surface measuring means S in the width direction of the road so that the numbers and positions of displacement gauges 2, 3, and 4 are uniformed. While the measuring wheel 1 travels, the outputs of the respective sets of road surface measuring means S1 - S4 are inputted to a personal computer to perform arithmetic processing. Conse quently, the rugged profile measured shape on the straight line in the travel direction of the measuring vehicle 1 facing the respective sets of road surface measuring means S1 - S4 is obtained and the rugged profile in the width direction of the road is found by curve approximation from the measured shapes of the respective sets to obtain the rugged profile of the entire measured road surface W.

Description

[Detailed Description of the Invention] [Objective of the Invention] (Industrial Application Field) The present invention measures the road surface unevenness profile in the traveling direction on a 1lIj road surface using a wave meter by driving a measurement vehicle, and also measures the unevenness in the road width direction. The present invention relates to a road surface measurement method that obtains the uneven profile of the entire road surface using a wave meter 811, by approximating the profile to a curve.

(Prior Art) The surface of a road, not only an unpaved road but also a paved road, is not completely smooth and has various unevenness. As a result, vehicles traveling on the road are subjected to complex forces that depend on the shape of the road's unevenness and the speed at which they are traveling. If we divide these forces into components in the vertical, longitudinal, and lateral directions of the car, we get
In particular, vertical force has a close relationship with vibration ride comfort and cargo damage. Furthermore, it is the biggest cause of deformation and destruction of the vehicle body. Therefore, understanding the degree of unevenness of the entire road surface is essential for the development of automobiles.

As methods for measuring the uneven profile of a road surface, methods using a multi-wheel fixed wheel metal and methods using a servo vibration meter are widely known. The method of using the multi-wheeled N1 rolling stock is to set a reference line using the average of multiple links and measure the unevenness of the road surface by the movement of the measurement wheel, but the device is complicated and the measurement speed is slow. , long-distance road surface planning
It is not suitable for doing so.

In addition, the method of using a servo vibration meter is to attach a measuring wheel to a measuring car, calculate the relative distance between the measuring car and the road surface by the movement of the measuring wheel, and calculate the vertical displacement of the measuring car by double integration of the acceleration. This method calculates the unevenness of the road surface by subtracting them. Although the measurement speed has been improved to some extent, consideration must be given to resonance, as the measurement wheels vibrate when they come into contact with the road surface.

In addition, in order to solve the above-mentioned problems, the above-mentioned 111
Instead of a servo vibration meter with fixed wheels, a non-contact laser displacement meter is used, which is mounted on a measuring vehicle and while driving on the road to be measured, irradiates the road surface with a laser beam and measures the reflection from the road surface. A method is also known in which the uneven profile of a road surface is measured using a beam.

(Problem to be Solved by the Invention) However, as described above, even if a non-contact laser displacement meter is mounted on a measurement vehicle and the measurement is carried out while one vehicle is running, the displacement of one non-contact laser Since the measurement is performed using a meter, if the vehicle body bounces due to input from the road surface, a total of 11111 errors will occur. Therefore, it is necessary to drive the same road to be measured many times to improve accuracy by a total of a-1. Furthermore, the running speed of the measurement vehicle is limited and measurements cannot be taken at normal running speeds, so when measuring a road surface such as an expressway, it is not possible to drive along with general vehicles.

This invention was made with attention to the above-mentioned circumstances, and its purpose is to be able to quickly measure the total speed at normal running speeds, and to accurately measure the total value even when the vehicle body is bouncing.
1) To provide a road surface measurement method that can improve the reliability of measurement data by using J and obtain the unevenness profile of the entire road surface by calculating the road surface unevenness profile in the road width direction from a total of n1 shapes in the traveling direction by curve approximation. There is a particular thing.

[Structure of the invention]

(Means and effects for solving the problem) In order to achieve the above-mentioned object, the present invention provides a measurement vehicle with three or more non-contact laser displacement meters arranged in a straight line along the longitudinal direction of the vehicle body. A set of road surface needle DI means arranged at intervals is set as one set, and a plurality of sets of road surface measuring means are arranged by aligning the number and position of non-contact laser displacement meters in the road width direction with reference to this set of road surface measuring means. and calculates and processes the outputs from the road surface needle J means of each set while driving the road surface needle J1 means, and calculates an uneven profile on a straight line along the traveling direction of the total ΔII vehicle facing the road surface needle J1 means of each set. This road surface meter tPj method is characterized in that the unevenness profile of the entire measured road surface is obtained by obtaining a total of Δ11 shapes and calculating the unevenness profile in the road width direction from each set of measured shapes by curve approximation.

Here, to explain the measurement principle with reference to Fig. 1, numeral 1 is a measurement car, and sensors A, C, and B as non-contact laser displacement meters are arranged in a straight line along the front and rear direction of the car body. are arranged in this order, and the space between the A sensor and the B sensor is defined as the space between the LSA sensor and the C sensor, and the space between the C sensor and the B sensor is defined as L2.

A: CA sensor output) B: (B sensor output) C: (C sensor output) f (X) : (road surface function) g (X) : (total ill system output).

Then, if g (X) is expressed using f (X),...
・ (1) On the other hand, if g (X) is expressed using the sensor output, (1)
From the formula, when the relationship between g (X) and f (X) is Fourier transformed, G (ω) = P (ω) X [1-I, 2/Lx EXP
(-jωL+)-1, + / L X EXP (j
ωL2) ]−F(ω)Xl+(ω) F(ω)−G(ω)Xl+(ω) F(ω) represents the measured road surface in the frequency domain. By performing an inverse Fourier transform on F(ω) and expressing it in the time domain f (X), it is possible to reproduce the uneven profile of the road surface in the traveling direction of the total M1 vehicle 1.

(Example) Hereinafter, one embodiment of the present invention will be described based on the drawings.

FIGS. 2 to 6 show a road surface measurement method for obtaining a road surface unevenness profile on a straight line along the traveling direction of a vehicle. The measurement car 1, which is a vehicle, has three non-contact laser displacement meters 2.3
and 4 are provided, as well as a non-contact optical speed meter 6.

The non-contact laser displacement gauges 2.3 and 4 are arranged in a straight line along the longitudinal direction of the measuring vehicle 1.

Then, set the distance between the non-contact laser displacement meters 2 and 3 to LI
If the interval between 3 and 4 is L2, then L1≠L2 is set.

Output signals from the three non-contact laser displacement gauges 2.3 and 4 are input to the A/D converter 8 via the displacement gauge processor 7 mounted on the vehicle 11-1.

Further, the output signal from the non-contact optical displacement meter 6 is input to the A/D converter 8 via the speedometer processor 9. The output signal from the A/D converter 8 is input to the personal computer 10, and a total of 7111J data are saved or printed on a floppy disk.

Therefore, while the measurement vehicle 1 is traveling on the road W to be measured, each of the non-contact laser displacement meters 2.3 and 4 irradiates the road surface W to be measured with laser light and receives the reflected light.
The obtained road surface displacement data is processed through the routine shown in the flowchart shown in FIG. 4, and the uneven profile of the wave meter Δ-1 road surface W along the traveling direction of the measurement vehicle 1 can be measured.

That is, the road surface displacement data output from each non-contact laser displacement meter 2.3 and 4 is calculated as the system output g (X) in step 1, and is combined with the vehicle speed data output from the non-contact optical speed meter 5 in step 2. Based on a total of 11FJ
Calculate the time and total 1 (FJ short distance.Furthermore, in step 3, Fourier transform [g (ω) is applied, system transfer function H (ω) is considered in the frequency domain, and in step 4, F (ω
)-G(ω)/H(ω). Further, by inputting the power spectral density S (n) and performing an inverse Fourier transform [F (ω) in Step 5, the road surface profile f (X) in the traveling direction can be obtained in Step 6.

That is, F(ω) represents a total of 411 road surfaces in the frequency domain. By expressing F(ω) in the time domain f (X) by inverse Fourier transformation, the uneven profile of the road surface along the traveling direction of the #1111 vehicle 1 can be reproduced.

In such an embodiment, non-contact laser displacement meters 2 and 3
If the interval between 3 and 4 is set to Ll, and the interval between 3 and 4 is set to, for example, L + -L 2, the transfer function becomes as shown in Fig. 7 (a), and at point a, there is no transfer. The function becomes zero and there is no output as a system. Therefore, the range that can be continuously measured is the range from point b to point C. In other words, three non-contact laser displacement meters 2.3 and 4
In the case of L and -L2, the system periodically has unmeasurable road surface wavelengths.

However, as explained earlier, when Ll≠L2 with the three non-contact laser displacement meters 2.3 and 4, the transfer function has no part where it becomes zero, and as shown in FIG. 7(b), Range that can be measured continuously, point b ~
Point C is enlarged.

The road surface measurement method for obtaining such an uneven profile of the road surface W by the wave meter AP1 is as shown in FIGS. , 1 facing the non-contact laser displacement meter 2.3.4 along the traveling direction of the measurement vehicle 1 with respect to the road width of the road surface W to be measured.
This means that only the portion of the road surface profile f (X) on the straight line cannot be measured.

However, even in the width direction of the measured road surface W, which is the vehicle width direction of a total of 21 vehicles 1, there are usually complex irregularities such as so-called rut marks, and it would be convenient if the road surface irregularity profile in this direction could also be measured. good.

Therefore, as shown in FIG. 8, a plurality of sets of road needles A1 means S are arranged on the total AP1 vehicle 1 at predetermined intervals in the road width direction. Each road surface measuring means S... may be, for example, a combination of three non-contact laser displacement meters 2.3.4 and non-contact optical speed meters 5, which are spaced at different intervals, as described above. . In other words, it is necessary to make the number of non-contact laser displacement meters 2.3.4 the same for each row of road surface measuring means S... and to align their positions so that there is no misalignment in the vehicle width direction. be.

Then, each of the road surface measurement means S forms a road surface needle ΔP1 in the manner described above, and obtains a road surface unevenness profile along the traveling direction of the road surface W to be measured. In the case where four sets of road surface measuring means S are provided, for example, as shown in FIG.
Four road surface unevenness profiles along the traveling direction f (X)
... can be done for a total of n1. Next, a predetermined position intersecting the traveling direction, for example, Xn and each uneven profile f (X)
The intersection point Z with ... is approximated by a curved line to estimate the road surface unevenness profile along the road width direction at the predetermined position Xn.

The more closely spaced the points you select, the more curve approximation will be obtained and the more refined it will be. As a result, it is possible to measure the uneven profile shape of the entire road surface from the uneven profile not only in the traveling direction of the measurement vehicle 1 but also in the road width direction.

Specifically, as shown in FIG. 10, a plurality of non-contact laser displacement meters 2.3, . 1 consisting of
With the set of road surface measuring means S1 as a reference, a plurality of sets of road surface measuring means Δ-1, for example S2 to S4, are arranged at predetermined intervals in the road width direction. Each set of road surface measuring means S1 to S4 must have the same number of non-contact laser displacement meters and must align their positions in the road width direction.

Therefore, while the measuring vehicle 1 is traveling on the road W to be measured, each set of road surface measuring means S1 to S4 measures the road surface displacement on a straight line facing each other along the traveling direction. Calculation processing is performed for each group of road surface measuring means S1 to S4 through a routine according to the flowchart described above, and a road surface unevenness profile f+ along the traveling direction of the measuring vehicle 1 for each group as shown in FIG. (X), f2 (X), f3 (X),
Obtain f4 (X).

A routine in which the road surface measuring means S1 to S4 of each set obtains a road surface unevenness profile along the traveling direction is a first routine.
The arithmetic processing from step 1 to step 6 of the flowchart shown in FIG. 2 is all the same. Next, in step 7 of the flowchart shown in the figure, the unevenness profile f+ (X), fz (X), f* along the traveling direction for each group is calculated.
(X).

f and (X) are drawn on one drawing as shown in FIG. Then, in step 8, the predetermined position Xn in the traveling direction and each road surface profile fl (X) in FIG.
, f2 (X), f3 (X).

Intersection point Z with f, (X), Z2. Find Z, , z4 and approximate the curve. Therefore, the road surface unevenness profile in the road width direction at the predetermined position Xn can be estimated. By obtaining a large number of such curve approximations, the wave meter? #1 The overall unevenness profile of the road surface W can be made by a total of i4N.

As a result, it is possible to estimate not only the road surface unevenness profile along the traveling direction of the measurement vehicle 1 but also the road surface unevenness profile in the road width direction, which is the vehicle width direction, to approximately accurately measure the overall road surface unevenness profile.

Although three non-contact laser displacement meters are provided in the above embodiment, the present invention is not limited to this. For example, by providing four non-contact laser displacement meters, measurement can be performed using four different systems. This is equivalent to running a total of 1111 times on the same road surface under the same conditions four times in one run. Therefore, it is possible to significantly shorten the measurement time, improve the total accuracy by 11-1, and improve the reliability.

[Effect of the invention] As explained above, according to the present invention, a total of Δ11 cars,
One set of road surface measurement means is made up of three or more non-contact laser displacement meters arranged at different intervals in a straight line along the longitudinal direction of the vehicle body, and this set of road surface measurement means is used as a reference. A plurality of sets of road surface measuring means are arranged with the number and position of non-contact laser displacement meters aligned in the road width direction, and while the measuring vehicle is running, the output from each set of road surface measuring means is processed, and the road surface of each set is calculated. By obtaining the unevenness profile measurement shape on a straight line along the traveling direction of the total Ap1 vehicle facing the measuring means, and calculating the unevenness profile in the road width direction from the total ΔN shape of each set by curve approximation, the wave meter A-1 road surface is obtained. It is possible to obtain the overall unevenness profile, expand the measurement data and improve reliability, and even on the expressway, it is possible to achieve a total of 1 fl 11 at normal high speed, regardless of the bouncing of the vehicle body. , there is an effect that the total Ap1 can be accurately calculated.

[Brief explanation of drawings]

Fig. 1 is a side view of a total AFJ vehicle for explaining the present invention in detail, Fig. 2 and the following show an embodiment of the present invention, Fig. 2 is a side view of a measurement vehicle, and Fig. 3 is a side view of a measurement vehicle. Figure 4 is a flowchart for obtaining a road surface profile on a straight line along the direction of travel, Figure 5 is a cross-sectional view schematically showing the total illll state, and Figure 6 is the direction of travel. Road surface profile diagram on a straight line along , Figure 7 (a)
(b) is a graph showing the relationship between road surface wavelength and amplitude (transfer function of the system), and Figure 8 is a graph showing the relationship between road surface wavelength and amplitude (transfer function of the system).
9 is a cross-sectional view schematically showing the condition 1. Figure 9 is a road surface profile diagram obtained by the measurement system in Figure 8. Figure 10 is a cross-sectional view schematically showing the state
The figure is a schematic plan view of a measuring vehicle equipped with a total of 11 means for obtaining a road surface profile along the road width direction from the road surface unevenness profile along the traveling direction, FIG. 11 is a road surface profile diagram of the entire road surface, and FIG. 12 is a flowchart thereof. It is a diagram. 1... Measuring vehicle, 2.3.4... Non-contact laser displacement meter, SI or S4... Road surface measuring means.

Claims (1)

[Claims] The measurement vehicle is equipped with a set of road surface measurement means consisting of three or more non-contact laser displacement meters arranged at different intervals in a straight line along the longitudinal direction of the vehicle body, and this set of road surface measurement means is provided. arranging a plurality of sets of road surface measuring means with the number and position of non-contact laser displacement meters aligned in the road width direction based on the means, and calculating and processing the output from each set of road surface measuring means while the measuring vehicle is running; By obtaining the unevenness profile measurement shape on a straight line along the traveling direction of the measuring vehicle facing each set of road surface measuring means, and by calculating the unevenness profile in the road width direction from the measurement shape of each set by curve approximation, the entire measured road surface is A road surface measurement method characterized by obtaining an uneven profile.