JPH0432705A - Road sectional unevenness measuring instrument - Google Patents

Abstract

PURPOSE:To increase maximum measurable width by encoding tracks obtained by plural couples of cameras and a light source with a spot beam and composing one track. CONSTITUTION:The spot beam light source 16 provided on the center axis of a vehicle body 12 emit the spot beam 140 in a specific direction about a road surface. This beam 104 irradiates a specific position in the overlap irradiated area of fan beams. Further, a data processor 24 extracts a coupling pointer according to an image 150-2 photographed by a CCD camera 14-2. Here, the coupling pointer indicates the irradiation position of the beam 140. For example, an area which is expected to be irradiated with the beam is set as a coupling pointer search area in advance and the gravity of center of brightness of this area is extracted to find a coupling pointer 170-2. Then, the device 24 couples coupling points 170-1 and 170-2 regarding both CCD cameras 14-1 and 14-2 and composes one track of tracks 130-1 and 130-2 by using the result.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a road surface transverse unevenness/IPI determining device, and particularly to an improvement in its maximum measurable width.

[Prior Art] Various types of devices are known that measure distance without contact, such as roads, and devices that measure distance based on video information captured by a camera or the like.

An example of such a device is a cross-road surface unevenness measuring device. This device measures the unevenness of a cross-section of a road surface in a non-contact manner.

A typical AI determination method adopted by the road surface transverse unevenness API determination device is the optical cutting method.

In this method, a light beam is emitted from a blade on the road surface, the trajectory drawn by this light beam on the top of the road is captured by a camera, and the unevenness across the road surface is determined from the information obtained thereby. Because it is necessary to scan the road surface, the light beam is irradiated diagonally above the road surface in a fan shape. This fan-shaped light ray is generally called a fan beam.

The road surface transverse unevenness 7Ip+ constant device is normally loaded on a vehicle. That is, while the vehicle is moving, the unevenness of the cross section of the vehicle is determined at any time, information regarding the road surface is collected, and the collected results are used for the operation control of the vehicle.

In this way, it has conventionally been possible to determine the transverse unevenness of a road surface without contact.

[Problem A to be Solved by the Invention] However, in the conventional device, there is a limit to the width in which the maximum Δallj can be determined.

For example, consider a structure in which only one fan beam light source and one camera are mounted on a vehicle as the simplest structure. In this case, the maximum measurable width may be improved by increasing the height of the camera, but the resolution of the camera may be degraded. Therefore, to ensure resolution, the apr is approximately 3 m.
This is the limit on the number of people allowed.

Furthermore, if a plurality of fan beam light sources and cameras are arranged in parallel, it is expected that the maximum measurable width can be secured as a whole, exceeding the maximum measurable width per camera. However, simply installing them side by side will cause positional errors and
It is not possible to compensate for variations in the fan beam trajectory caused by 4. As a result, it has become difficult to accurately determine Δ111 of unevenness across the road surface.

The present invention was made with the aim of solving these problems, and it is possible to obtain accurate measurement results by ensuring a maximum rotation width without deteriorating the resolution. The purpose of the present invention is to provide a device for determining ApJ.

[Means for Solving the Problems] In order to achieve the above object, the present invention includes a plurality of fan beam light sources and cameras mounted on a vehicle body, and an area commonly irradiated by adjacent fan beam light sources. The analyzing means for processing information photographed by the camera combines adjacent trajectories using the trajectory of the light ray by the spot beam light source as a reference point.

[Operation] In the present invention, images taken by a camera are synthesized based on the locus of the spot beam light source. As a result, even if trajectory fluctuations occur due to asymmetry in the installation location or vehicle body inclination, this is compensated for and accurate δIII determination is performed, resolution deterioration is prevented, and the maximum measurement nJ power range can be widened. becomes.

[Embodiments] Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

FIGS. 1 and 2 show the arrangement of the light beam (and the CCD camera) in a road cross-sectional unevenness measuring device according to an embodiment of the present invention.

Of these figures, Figure 1 is a view from the side of the vehicle body.
FIG. 2 is a view from the rear of the vehicle body.

In this embodiment, fan beams 100-- which are fan-shaped light rays directed toward the road surface from diagonally above.
1 and 100-2 are fan beam light sources] 0-1 and 1
Issued by 0-2.

These fan beam light sources 10-1 and 10-2 are connected to the vehicle body 1.
It is installed on both the left and right sides of the rear of the 2.

The fan beam light sources 10-1 and 10-2 are light sources such as laser oscillators. The installation height is approximately 0.65 m from the road surface, and the irradiation position of the fan beams 100-1 and 100-2 is set 1.-3 m behind the vehicle body 12 from the 1-i1 irradiation position. These positional relationships are based on the spread angle of the fan beam 100, the incident angle θ, and the road surface bug surface 1〕0.
It is determined by the upward irradiation width, etc.

For example, as shown in FIG.
/2).

Further, the actual road surface on which the fan beam 100 is illuminated 11.1 is not an exact plane, but a surface that matches the concave portions.

Here, the actual road surface is approximated to an ideal road surface reference surface]10. Actual road surface and road surface base/III, 1
If f1j110 exactly match, the fan beam 100 will draw a linear trajectory on the road surface at a position determined by the parameter of the incident angle θ shade.

However, an actual road surface has transverse irregularities.

That is, a part of the actual road surface is in a depressed position when viewed from the road surface reference surface]10.

Let this recess be L, and let the recessed surface 120 represent a plane located as low as possible when viewed from the road base surface 110.
Compared to the trajectory drawn in the portion where the actual road surface and the road surface reference plane 110 coincide, the position of the dent is drawn a distance behind the vehicle body 12 relative to the road surface reference plane 110 by a distance determined by the incident angle θ. In this case, from the equation for the incident angle θ described above, the positional deviation of the trajectory due to the dent is 2L.

Further, the irradiation widths of the fan beams 100-1 and 100-2 are set so that the irradiation areas overlap, for example, with a width of about 0.8 m.

The trajectories of fan beams 100-1 and 1002 emitted by fan beam light sources 10-1 and 10-2 are CC
Photographs are taken by D cameras 14-1 and 14-2, respectively. The CCD cameras 4-1 and 14-2 are placed above the fan beam light sources 101 and 10-2, specifically at a height of about 1.9 m behind the vehicle body 2.

CCD cameras 14-1 and 14-2 are fan beam 1
00-1 and] 00-2, the scanning direction is set perpendicular to the trajectory (that is, perpendicular to the back of the vehicle body 12).

CCD camera] The installation height of 4-1 and 14-2 is
It is determined from the focal length of the lens used, the size of the light receiving element surface, and the possible width of 3!4111 per vehicle, and the mounting interval is determined by the width of the vehicle body 12.

Further, corresponding to the fan beam light sources 10-1 and 10-2, the fields of view of both the CCD cameras 14-1 and ]42 are set to overlap. The overlap width is about 0°4m, and CC
The viewing angle of the road surface 110 from the D cameras 14-1 and ]4-2 is approximately 18°.

From the CCD camera 14, a corresponding fan beam light source 10
When the trajectory of the fan beam 100 is photographed, it becomes as shown in FIG. This figure is a diagram when the track u 130 is viewed from a direction perpendicular to the road surface (that is, the direction of the CCD camera 4 with respect to the road surface).

For example, if a part of the road surface is deeply depressed, the trajectory 130 curves backward by 2L at the depressed portion according to the equation for the incident angle θ described above. The CCD camera 14 photographs such a trajectory 130 and provides it to processing to be described later.

Further, in FIG. 2, a spot beam light source 6 according to a feature of the present invention is shown.

This spot beam light source 16 is a fan beam light source 10.
-1 and 10-2, it is a light source such as a laser oscillator.

The mounting position on the vehicle body 12 is any position on the center line of the vehicle body 12. The spot beam light source 16 irradiates a spot beam 140 to a predetermined position on the road surface reference surface 110 soil. The irradiation position of this spot beam 140 is set approximately 50 mm in front of the irradiation positions of the fan beams 100-1 and 1002 so that it can be easily distinguished from the fan beams 100-1 and 100-2. C.C.
D cameras 14-1 and 14-2 are fan beam 100
This spot beam 1 along with the trajectories of -1 and 100-2
40 irradiation spots are also photographed.

With this arrangement, if the width of each fan beam light source] 0 is about 2.9 m, the fan beam 100-1
and 100-2, the width of the irradiation is about 4.8m, and the width of the CCD camera, which includes 4-1 and 14-2, is about 5rn.

The circuit configuration of this embodiment is not shown in FIG.

The circuit shown in this figure is a circuit that specifically processes the appearance of images taken by the CCD cameras 4-1 and 14-2. In addition, fan beam light a:y, 10
-1.10-2 and the spot beam light source] 6's drive system supplies these with 7h power ((((It is only the power supply i11;j and its switch system, so the explanation will be omitted here.

In FIG. 5, the CCD cameras 4-1 and 4-2 have 8-bit A/D converters 18-1 and 4-2, respectively.
8-2 is connected. i.e. CCD camera]4
The images taken by -1 and 14-2 are quantized to 8 bits, and output from the A/D converters 18] and 18-2 as data with 8-bit luminance resolution! 14 will be strengthened.

Line memories 20-1 and 2.2 are connected to the rear stages of the A/D converters 18-1 and ]8-2, respectively. These line memories 2o-1 and 20-2 are A/D
The outputs of converters 18-1 and 18-2 are stored for one scanning line period and output to the subsequent stage.

Line memories 20-1 and 20-2 are connected to data processing device 24 via interface 22. This data processing device 24 is a device that performs calculations of road cross-sectional irregularities.

Next, the operation of this embodiment having such a configuration will be explained.

First, each fan beam light source 1o emits a fan beam 100 with a predetermined irradiation width. This fan beam 10
0 draws a trajectory 13o on the road surface, and this trajectory 130 is photographed by a corresponding CCD camera]4.

FIG. 6 shows the power distribution of the CCD camera 4 in the scanning line direction.

CCD camera] 4 has an output of 8 due to the A/D converter.
It is a camera with a bit brightness resolution (power). When photographing the trajectory 130, as shown in FIG. 6, a signal having a brightness peak is output.

In this embodiment, the trajectory 130 is determined by the data processing device 24 based on such a luminance distribution.

For example, the center of gravity of the brightness distribution may be determined by averaging the brightness of the pixel with the maximum brightness and a total of n pixels adjacent thereto.

If such arithmetic processing is performed over all scanning lines, a locus 130 as shown in FIG. 4, for example, will be obtained as a line connecting the positions of the centers of gravity.

The above-mentioned operation is performed by a pair of fan beam light sources] 2 and C.
This is an operation performed regarding the CD camera 14. The feature of the present invention is the operation of synthesizing trajectories obtained by a plurality of parallel fan beam light sources 12 and CCD cameras 14 (two in the embodiment). This operation will be explained below.

In FIG. 7, the principle of extracting a link pointer performed by the data processing device 24 in this embodiment is illustrated.

In this figure, 150 indicates an image photographed by the CCD camera 14. In this figure, for the purpose of explanation, an image of one CCD camera] 4, specifically, an image of the left CCD camera 14-2: 1.50-2 is shown.

In this embodiment, a spot beam light source 6 provided on the central axis of the vehicle body 12 emits a spot beam 40 in a predetermined direction on the road surface. This spot beam 1.40 is irradiated to a predetermined position inside the overlapping irradiation area of fan beams 100J-1 and 100-2, as described above.

The data processing device 24 extracts the connection pointer based on the video 150-2 taken by the CCD camera 14-2.

Here, the coupling pointer refers to the irradiation position of the spot beam 140.

For example, a region expected to be irradiated with the spot beam 140 is set in advance as the combined pointer search area 160-2. This join pointer search area 1
60-2, if the center of gravity of luminance is extracted using the same principle as the locus 130 extraction in FIG.
-2 is required.

Next, the data processing device 24 uses both CCD cameras] 4-1
and 14-2 binding pointer]70] and 170-
2, and using this result, traces 130-1 and 13
Synthesize 0-2.

FIG. 8 shows the principle of trajectory synthesis in this embodiment.

Assume that the CCD cameras 14-1 and ]4-2 are placed exactly at the center plane of the insect body 12, and the vehicle body 12 is not tilted at all.

At this time, if images 150-1 and 150-2 taken by CCD cameras 14-1 and 14-2 are combined according to the positions of CCD cameras 14-1 and 14-2, trajectories 130-1 and 130- 2 is a single combined trajectory.

However, in general, the mounting of the CCD cameras 14-1 and 142 may occur due to positional deviation or inclination of the vehicle body 12.
and 130-2 do not match.

In this embodiment, in order to eliminate this discrepancy and obtain one combined trajectory, perpendicular lines 180-1 and 1802 are drawn from joining pointers 170-1 and 170-2 to trajectories 130-1 and 130-2. The images are translated and rotated so that they match.

First, in the direction of the arrows 190 and 200 in FIG.
The image 150-2 is moved by a coordinate difference of -2. As a result, the parallel movement component of the deviation between the trajectories 130-1 and 130-2 is corrected.

Next, the rotational component is corrected. This correction is performed, for example, by photographing a reference trajectory on a horizontal road surface in advance for each of the CCD cameras 14-1 and 14-2, and then matching the images. Zunawaji, CCD camera 14-
The image 150-2 is rotated relative to the image 1.50-1 so that the reference trajectory obtained by the image 1.1 and the reference trajectory obtained by the CCD camera 14-2 are on a -straight line. This results in
Correction of rotational components is achieved.

In this way, one combined trajectory can be obtained using the combined pointers 170-1 and 170-2. This trajectory is a trajectory whose width is expanded by using two pairs of fan beam light sources 12 and CCD cameras 14 compared to the conventional case of one pair. Further, the shape represents unevenness in the cross-sectional direction of the road surface, and by converting it into data in the cross-sectional direction of the road surface by XY conversion, it is possible to obtain the unevenness across the road surface. Therefore, it is possible to determine the irregularities across the road surface without any problems such as a decrease in measurement accuracy.
And the maximum measurable width is expanded.

FIG. 9 shows the principle of correcting the inclination of unevenness across the road surface based on the combined trajectory when the vehicle body 12 inclines.

That is, when the vehicle body 12 tilts, an angular deviation occurs in the road cross section between the actual road cross-surface unevenness and the road cross-surface unevenness determined by the photographed and synthesized trajectory. This is due to the difference in distance between the CCD cameras 14-1 and 14-2 and the road surface.

In this embodiment, this is corrected using the least squares approximation U.

Let us assume that when the cross-road unevenness found from the trajectory photographed and synthesized as described above is expressed as it is on a cross-section of the road surface, it is represented by a curve 210 as shown in FIG.

However, if the vehicle body 12 is inclined, the inclination is actually calculated as a difference in angle on the cross section of the road surface on the curve 210.
will be included in.

Therefore, using this curve 210, an approximate straight line 220 is determined by the method of least squares. This approximate straight line 220 corresponds to the curve 21
It shows the road surface reference surface expected from 0, and intersects with the actual road surface reference surface 110 at a certain angle. This angle can be considered to be equal to the inclination angle of the vehicle body 12.

For this reason, in this embodiment, the angle formed by the approximate straight line 220 and the road surface reference plane 110 is determined, and this angle height curve 2 is calculated.
]0 is rotated to obtain the actual road cross-sectional unevenness 230.

In this manner, in this embodiment, even if the vehicle body 12 is tilted, the tilt angle of the vehicle body can be approximated and corrected based on the combined locus.

Note that the settings such as the arrangement used in the above explanation are not limited. For example, it may be set appropriately depending on the type of medium or the environment of the road surface to be measured.

Furthermore, the number of pairs of CCD cameras and fan beam light sources is not limited to two pairs. When using a larger number of χ and i, a spot beam light source may be placed at an intermediate position between adjacent fan beam light sources and used for matching both fan beams.

Furthermore, various calculations in the data processing device 24 may be based on other algorithms. That is, a plurality of CCD cameras 14 adjacent to each other by a coupling spot
It doesn't matter if it has something in common in terms of compositing images.

The camera, light source, etc. may be other than the CCD camera, laser oscillator, etc.

[Effects of the Invention] As explained above, according to the present invention, since the trajectories obtained by multiple pairs of cameras and light sources are matched and synthesized by a spot beam, it is possible to expand the maximum measurable width. Therefore, measurement accuracy can be maintained.

[Brief explanation of drawings]

FIG. 1 is a side view showing the light source and camera arrangement in a road surface unevenness determination device according to an embodiment of the present invention, FIG. 2 is a rear view showing the light source and camera arrangement in this embodiment, and FIG. is a longitudinal cross-sectional view of the road surface showing the mode of fan beam irradiation in this embodiment, FIG. 4 is a locus diagram of the fan beam in this embodiment, FIG. 5 is a circuit diagram of the data processing system in this embodiment, Figure 6 is a histodarham diagram showing the power distribution in the scanning line direction of the CCD camera used in this example, Figure 7 is an image diagram showing the joining pointer in this example, and Figure 8 is an image synthesis diagram in this example. FIG. 9 is a principle diagram of the vehicle body tilt correction process in this embodiment. 10 ・ 12 ... ] 4 ... 16 ... 24 ... 100 ・ 130 ... 140 ... 150 ... Core 0 ... Fan beam light source Car body CCD camera Spot beam Light source Data processing device Fan beam Trajectory spot beam image combining pointer CCD camera installation 1 Bu Ryohata (side of vehicle body) Figure 1 CCD camera measurement width (back of vehicle body) Figure 2 27/Beam O irradiation Figure 3 Trajectory seen from CCD camera Figure 4 Power distribution erased in the direction of the scan line (Fig. 6) Extraction of coupled voids/res Fig. 7 Circuit configuration of the embodiment (processing system) Fig. 5 Principle of image composition from two cameras Fig. 8

Claims (1)

[Claims] A fan beam light source mounted on a vehicle emits a fan-shaped light beam diagonally downward from the rear of the vehicle body, and a fan beam light source installed above the light source so as to photograph the trajectory of the light beam emitted from the fan beam light source. In a road surface cross-sectional unevenness measuring device having a camera and an analysis means for determining the cross-sectional unevenness of the road surface by analyzing the trajectory of the photographed light beam, a plurality of fan beam light sources and cameras are mounted on a vehicle body, and adjacent fan beam light sources are provided. a spot beam light source that irradiates at least a part of the area that is commonly irradiated by the road surface unevenness, and the analysis means synthesizes adjacent trajectories using the trajectory of the light ray by the spot beam light source as a reference point. measuring device.