JPS62215816A - System for measuring property of road surface - Google Patents

Abstract

PURPOSE:To enhance measuring accuracy, by moving a TV camera with the change in the incident angle and scanning angle of laser beam to a road surface so that a transverse profile to be picked up is received in an image pickup visual field. CONSTITUTION:Movable shafts 207, 208 are constituted so as to be made movable to the before-and-behind direction [direction shown by an arrow (b)] of a measuring vehicle 2 and TV camera 209, 210 are moved by scanning beams from laser scanners 205, 206 corresponding to the unevenness of a road surface so that the transverse profile drawn on the road surface is received in an image pickup visual field. For example, when the unevenness of the road surface is little, the angle theta3 of inclination of the laser scanners 205, 206 is adjusted so that laser beams scanned by the laser scanners 205, 206 are allowed to irradiate the road surface at an incident angle theta4'. At this time, the TV cameras 209, 210 are moved to a position having an image pickup position d2 and the transverse profile drawn on the road surface corresponding to the properties thereof by laser beams scanned at the incident angle theta4'' is picked up.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention scans a road surface in a line with a laser beam, and generates a v11% profile drawn on the road surface according to its properties as a locus of the scanning light. The present invention relates to a road surface property measuring system that captures an image with a television camera and obtains measurement data indicating the property of the road surface to be scanned based on the N11l output.

(Prior Art) This type of conventional road surface V1-shaped measuring system has an overall structure as shown in FIGS. It is equipped with an optical mechanism 2, television cameras 3 and 4, a VTR (video tape recorder) 5, a monitor television 6, and the like.

5 and 6, a laser beam emitted from, for example, an argon (Ar) laser oscillator mounted in a laser tube 20 is transmitted through a laser scanner 21 consisting of a polygon scanner (rotary multi-plane scanning 8M), etc. Then, the light beam is directed vertically onto the road surface q1, and is repeatedly scanned in a line in a scanning direction perpendicular to the traveling direction of the measuring vehicle 1 (direction of arrow a).

On the other hand, the TV 7J cameras 3 and 4 are each given a considerable imaging viewing angle, and by connecting the imaging viewing angles, the scanning position of the road surface by the laser beam can be determined at least by the main beam of the laser beam. It is mounted at the rear of the measurement vehicle 1 so as to be able to capture an image from diagonally above with a scanning width.

At this time, when the road surface is viewed diagonally downward from the imaging planes of the television cameras 3 and 4, the locus of the laser beam scanning the road surface is a cross-sectional profile of the road surface, as shown in the figure, depending on the unevenness of the road surface. will be drawn.

This cross-sectional profile is imaged by the television cameras 3 and 4 by the above-mentioned function sharing.

In addition, the IiI image outputs of the television cameras 3d3 and 4 are synthesized by an image signal processing circuit, processed in relation to the passage of time (mileage), etc., and then processed to determine the road surface properties (such as ruts, etc.). It is measured as data indicating.

This road surface condition measurement data is recorded on the VTR 5 and also displayed on the television camera 6 as necessary.

The road surface condition measurement data recorded on the VTR5 in this way is
It is reproduced as necessary and used repeatedly, for example, for various work plans for the road surface whose properties have been measured.

[Problems to be Solved by the Invention] However, this type of conventional road surface quality measurement system has the following problems.

a. Due to the fixed arrangement of the television cameras 3 and 4, the range is limited, e.g. in the scanning position shown in FIG. A cross-sectional profile drawn on a convex part of the road surface that exceeds 100 yen will deviate from the N-image field of view, resulting in missing data from the road surface property measurement data, making it impossible to measure the road surface property accurately and with a high degree of rust depending on the unevenness of the road surface. .

b. In order to obtain a wide main scanning width corresponding to the imaging viewing angle of the two television cameras 3 and 4, scanning the road surface with one laser scanner 21 inevitably reduces the laser power, and the S in the imaging output /N ratio decreases.

The present invention attempts to solve these conventional problems.

[Means for solving problems]

The road surface quality measurement system of the present invention is installed in a measurement vehicle,
a laser scanner that can vary the incident angle and scanning angle of the laser beam with respect to the road surface depending on the unevenness of the road surface;
A television camera that images a cross-sectional profile of the road surface drawn on the road surface as a locus of the laser beam as the laser scanner scans the road surface, and changes in the incident angle and scanning angle of the laser beam with respect to the road surface by the laser scanner. Accordingly, the cross-sectional profile to be ml is mt
li field of view, and a measuring means for measuring road surface property data based on the imaging output of the cross-sectional profile by the television camera.

(Function) In the road surface condition measurement system of the present invention, the laser scanner scans the road surface by changing the incident angle and the scanning angle of the laser beam on the road surface according to the unevenness of the road surface, and the VIT image is also Since the television camera is moved by the moving means so that the desired cross-sectional profile falls within the imaging field of view, the image of the cross-sectional profile is taken. Therefore, it is possible to measure the properties of a wide range of road surfaces by effectively utilizing the imaging field of view of the television camera. It will be possible to do it.

In addition, for example, it becomes easy to configure a configuration in which two laser scanners are used and each laser scanner performs the above-mentioned road surface scanning. It will also be possible to prevent this.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

First, the scanning optical n of the road surface condition measurement system according to the present invention will be explained.
W4 has a configuration as shown in FIG. 1, and is mounted on the measurement vehicle 1 in a manner as shown in FIG.

In FIGS. 1 and 2, two laser tubes 201 and 202 (for example, using an argon laser beam oscillator as an oscillation source) are housed in a casing 200 provided on the roof of the measurement vehicle 1. ing.

Laser beams that are individually emitted from the laser tubes 201 and 202 in the longitudinal direction of the measurement vehicle 1 on a surface parallel to the road surface are incident on mirrors 2030 and 2031 that constitute the first mirror 51 structure 203, and are directed onto the road surface, respectively. After being reflected in the direction perpendicular to the second mirror tFIIf4
The laser beams enter the mirrors 2040 and 2041 constituting the laser beam 204, are again reflected from a surface parallel to the road surface in directions perpendicular to the emission direction of the laser beam and opposite to each other, and enter the laser scanners 205 tj and 206, respectively. .

FIG. 3 schematically shows the configuration of the laser scanner 206, in which FIG. 3(a) is a front view viewed from the rear of the measuring vehicle 1 in the front-rear direction, and FIG. 3(b) is shown in the same figure (
It is a right view of (a).

In FIG. 3, the laser scanner 206 includes a casing 2 supported between support plates 206o and 2061.
062 (consisting of a rectangular parallelepiped case and a cylindrical case combined) a movable mirror 2063 and the movable mirror 206
The casing 2062 is connected to a motor 2065 outside the support plate 2061.

In the laser scanner 206 having such a configuration, the laser beam reflected by the mirror 2041 of the second mirror m structure 204 enters the movable mirror 2063 q4 through the entrance hole provided in the support plate 2060.

Here, the movable mirror 2063 is moved directly to PilfJ1 by a motor 2064 driven by a drive control section (not shown).
It is rotated repeatedly at a constant period within a range of a rotation angle θ1 around the axis .

Therefore, the laser beam incident from the mirror 2041 is reflected according to the rotation angle θ1 of the movable mirror 2063, and becomes a scanning light with a scanning angle θ2 [see FIG. 3(a)]
.

In this state, the casing 2062 is connected to the motor 2065.
As a result, it is rotated about the straight line j2 and is fixed at a position tilted by an inclination angle θ3 from a position perpendicular to the road surface.

Along with this, the movable mirror 2063 also tilts, and the laser beam scanned by the movable mirror 2063 at a scanning angle θ2 is irradiated onto the road surface at an incident angle θ4 [see FIG. 3(b)]. .

Further, the rotation angle θ1 and the inclination angle θ3 of the movable mirror 2063 described above can be varied according to drive commands given to the motors 2064 and 2065 from respective drive control units, and thereby the laser scanner 20
6, the scanning angle θ2 and the incident angle θ of the laser beam
4 can also be variably controlled as desired.

Note that in the configuration of the laser scanner 206, the straight line 1
2 coincides with the incident optical path of the laser beam and is orthogonal to Ill on the movable mirror 2063, so even if the inclination angle θ3 of the movable mirror 2063 changes and the incident position of the laser beam changes, the rotation will not occur. The scan angle θ2 does not change unless the angle θ1 is changed.

The laser scanner 206 having such a configuration and capabilities is as follows:
Together with a similarly configured laser scanner 205, they are arranged to face each other as symmetrically as possible when viewed from the front-rear center axis of the measuring wheel 1, at both left and right ends at the rearmost position of the measuring wheel 1, as shown in FIG. 2, for example. It is set up.

And these laser scanners 205 and 206 have
Mirrors 2 each forming the second mirror mechanism 204
The laser beams incident from 040 and 2041 are assigned functions so that they can individually scan the road surface.

Normally, during such scanning, the laser scanner 20
5 and 206 are set at the same incident angle θ so that the respective scanning lights of the laser scanners 205 and 206 pass on the same scanning line and are connected at the center of the scanning line.
and scanning angle θ2 are set.

As the laser scanners 205 and 206 scan laser beams according to their respective capacities, a single cross-sectional profile is drawn on the road surface corresponding to the locus of the scanning light according to the properties of the road surface.

On the other hand, this! As shown in FIG. 2, two movable shafts 207 and 208 are provided protruding from a casing 200 mounted on the roof of the measurement vehicle 1 as a mechanism for capturing an image of the V.lli profile. Television cameras 209 and 210 are disposed at the tips of 207 and 208, respectively, so that their imaging surfaces are horizontal to the road surface.

The television cameras 209 and 210 are configured to image the entire transverse profile according to their respective functions, and each of the television cameras 209 and 210 has a field of view corresponding to the scanning width of the laser scans 205 and 206, respectively. A corner is given.

Furthermore, the movable shafts 207 and 208 are configured to be movable in the longitudinal direction (in the direction of the arrow) of the measuring vehicle 1, and as described later, the laser scanners 205 and 206 emit laser beams according to the unevenness of the road surface. Even when the incident angle θ4 of the beam on the road surface is varied, the television camera 2 is configured so that the cross-sectional profile drawn on the road surface by the scanning light (laser beam) with the incident angle θ4 falls within the imaging field of view.
09 and 210 can be moved.

Next, an example of the operation of this road surface quality measuring system will be explained with reference to FIG.

First, if the road surface has small irregularities, the laser scanner 2
The inclination angle θ3 of the laser scanners 205 and 206 is adjusted and fixed so that the laser beams scanned by the laser scanners 05 and 206 are irradiated onto the road surface at an incident angle θ'4. Furthermore, the scanning angle θ2 of each laser beam is adjusted to rA so that the scanning lights of the laser scanners 205 and 206 are connected at the center in the main scanning direction. At this time, the television cameras 209 and 210 are moved to a position A having a positive image position d1, and an image of a transverse profile drawn on the road surface according to its properties by the scanning light is imaged.

In general, in a scanning method in which a laser beam is irradiated diagonally from above, if the incident angle 04 is the same, the road surface is
Viewed from the imaging directions of 09 and 210, as the unevenness of the scanning road surface increases, its cross-sectional profile becomes greatly distorted in the sub-scanning direction, and depending on the situation, the field of view of the television cameras 209 and 210 may be distorted. You will end up going around a corner.

In order to solve this problem, for example, the angle of incidence 04 of the laser beam with respect to the road surface may be increased to suppress the distortion of the cross-sectional profile in the sub-scanning direction.

According to this method, when the unevenness of the road surface is small, the laser beam scanned by the laser scanners 205 and 206 is set so that the road surface is irradiated with an incident angle θ″4 (θ″4>θ′4). Scanners 205 and 20
Adjust the inclination angle θ3 of No. 6 and fix it.

Here again, the scanning angle θ2 of the laser beams is adjusted so that the scanning lights of the laser scanners 205 and 206 are connected at the center.

At this time, the television cameras 209 and 210 are moved to the B position with the imaging position d2, and as described above, the laser beam scanned at the newly set incident angle θ''4 draws images on the road surface according to its properties. 4 AltJ profile 13al.

Incidentally, the image pickup output of the vi position profile at this time needs to be appropriately corrected according to the incident angle θ''4.

i of the television cameras 209 and 210 obtained in this way
The li image output is subjected to processing such as synthesis by an image signal processing channel (not shown), and is detected as road surface property measurement data corresponding to the cross-sectional profile, and is recorded on a VTR or displayed on a monitor TV as necessary. .

[Effects of the Invention] As explained above, according to the road surface condition measurement system of the present invention, for example, two laser scanners are used to divide the temperature, and the incident angle and scanning angle of the laser beam with respect to the road surface are changed according to the unevenness of the road surface. The road surface is scanned with a specific main scanning width, and a television camera installed corresponding to the laser scanner is positioned at an appropriate position to draw a picture on the road surface at the scanning position of the laser beam according to its properties. Since the cross-sectional profile of the TV camera is accurately imaged and the road surface condition data at the scanning position is measured from the silver image output, the measurement field of view range is not limited and the entire viewing angle of the television camera is effectively utilized. It has the excellent advantage that it is possible to measure road surface properties with high precision, and that deterioration of the S/N ratio can also be kept to a minimum because a decrease in laser power is suppressed by the n-power sharing of the laser scanner.

[Brief explanation of drawings]

FIG. 1 is a perspective view conceptually showing an embodiment of the scanning optical mechanism in the road surface condition measuring system according to the present invention, and FIG. 2 is a perspective view of the scanning optical system 11FI shown in FIG. 41 measurement car 1
FIG. 3 is a perspective view showing an example of how the laser scanner 206 is installed in the scanning optical mechanism shown in FIG. FIG. 4 is a front view as seen from the direction, FIG. 4B is a right side view of FIG. A side view of the car 1. FIG. 5 is a perspective view conceptually showing the overall configuration of a conventional road surface quality measurement system, and FIG. 6 is a conceptual diagram of the road surface quality measurement system shown in FIG. 5 viewed from the side. 1...Measuring wheel, 2...Scanning optical mechanism, 3,4゜20
9.210...TV camera, 5...VTR16.
...Monitor TV, 20,201,202...Laser tube, 21,205,206...Laser scanner, 200.2062...Casing, 203...First mirror mechanism, 204...Second Mirror mechanism, 2030
．． 2031, 2040, 2041...Mirror, 206
0.2061... Support plate, 2063... Movable mirror, 2064, 2065... Motor, 207°208.
・・Movable moon・, θ1...Rotation angle, θ2...Scanning angle, θ3...Inclination angle, θ4...Incidence angle. Figure 6

Claims (3)

[Claims] (1) A laser scanner that is mounted on the measurement vehicle and can vary the incident angle and scanning angle of the laser beam on the road surface depending on the unevenness of the road surface, and as the laser scanner scans the road surface, the trajectory of the laser beam is a television camera that images a cross-sectional profile of the road surface drawn on the road surface; A road surface property measurement system comprising: a moving means for moving a television camera; and a measuring means for measuring road surface property data based on the imaging output of the cross-sectional profile by the television camera. (2) Two or more laser scanners are provided, and each laser scanner is individually set with an incident angle and a scanning angle of the laser beam with respect to the road surface so that the scanning of the road surface can be shared. A road surface condition measuring system according to claim (1). (3) Two or more television cameras are provided, and each television camera is individually provided with an imaging field of view that takes an image of the entire cross-sectional profile. The road surface quality measurement system described in item 1) and item (2).