JPH04291105A - Ruggedness measuring instrument utilizing light cutting - Google Patents

Abstract

PURPOSE:To effectively utilize information related to the luminance of the locus of a fan beam. CONSTITUTION:The picture of the locus of a light beam (a) on a plane (b) of measurement is taken with a photographing means B and a ruggedness calculating means F performs ruggedness calculation by using a light cutting method. A luminance distribution calculating means C finds the luminance distribution of the locus and an gravitational center calculating means D finds the gravitational center near the maximum value of the distribution. A significance discriminating means E executes threshold discrimination for discriminating whether or not the obtained gravitational center is significant and, when it is discriminated that the gravitational center is significant, a significant signal processing means G executes a prescribed process. When the plane (b) of measurement is painted, etc., a prescribed process can be executed by detecting the paint, etc.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an unevenness measuring device using optical cutting, which measures the unevenness of a measurement surface based on the locus of a fan beam irradiated onto a measurement surface.

0002

2. Description of the Related Art Conventionally, there has been known an apparatus for measuring road surface irregularities using a so-called optical cutting method. The photosection method is
This is a method in which a so-called fan beam is irradiated onto a measurement surface such as a road surface, and its trajectory (beam trajectory) is photographed to determine the unevenness of the measurement surface.

FIG. 7 shows the principle of the optical cutting method. As shown in FIG. 7(a), the surface 10 of the object to be measured is irradiated with a fan beam by the oscillator 12. That is, the beam is irradiated obliquely downward from above the surface 10 of the object to be measured so as to draw a fan shape. This beam of light is
It is called a fan beam because it emits a fan-shaped beam. On the other hand, a camera 14 is placed above the surface 10 of the object to be measured.
Photograph 00. This trajectory 100 becomes a trajectory reflecting the unevenness of the surface 10 on the image of the camera 14, as shown in FIG. 7(b). For example, if a groove with a width L and a depth H is provided on the surface of the object to be measured 10, the trajectory 100 in the camera image becomes a straight line with different steps in a section of width l and height h. When the camera 12 is installed so that the scanning direction is perpendicular to the beam trajectory 100 as shown in FIG. Then, the shape of the recess on the surface 10 can be determined as follows from the information l and h obtained from the camera image.

0004 L=kl H=kh　tanθ

[0005]

[Problems to be Solved by the Invention] However, in the conventional optical cutting method, the information obtained by irradiating the fan beam and photographing the beam trajectory is used only for measuring the irregularities on the surface of the object to be measured, and the functionality is poor. The problem was that it was low.

The present invention has been made to solve these problems, and aims to further enhance the functionality of an unevenness measuring device using optical cutting. In other words, by using the brightness difference of the beam trajectory on the measurement surface,
The purpose is to make it possible to perform necessary processing in response to this.

[0007]

[Means for Solving the Problems] In order to achieve the above object, the applicant of the present application proposes a concavity and convexity measuring device using optical cutting having a configuration as shown in FIG.

That is, the present invention provides a fan-shaped beam ray a
an irradiation means A that irradiates the measurement surface b; a photographing means B that photographs the measurement surface b and obtains image information related to the beam trajectory;
A brightness distribution calculation means C that calculates a brightness distribution on a scanning line that crosses a beam trajectory from video information, a center of gravity calculation means D that calculates a center of gravity near the maximum value of the brightness distribution, and a comparison of the brightness at the center of gravity with a predetermined threshold value. a significance determining means E for determining whether or not the local maximum value is significant; and a concavity/convex calculation means F for determining the concavity and convexity of the measurement surface b based on the image information when it is determined that the maximum value is not significant; Significant signal processing means G that executes predetermined significant signal processing when it is determined that there is a significant signal, and detects when there is a part with different brightness such as paint on the measurement surface b such as a road surface. It is characterized by executing significant signal processing such as reference position setting.

[0009]

In the present invention, a fan-shaped beam a, a so-called fan beam, is irradiated onto the measuring surface b. The beam locus obtained by the irradiation is photographed by the photographing means B and given to the luminance calculating means C as image information.

The brightness distribution calculating means C calculates the brightness distribution from the image information related to the beam trajectory obtained by the photographing means B, and the center of gravity calculating means D calculates the center of gravity in the vicinity of the maximum value of the brightness distribution. That is, if a treatment such as painting has been performed on the measurement surface b, this treatment causes a brightness distribution in the beam trajectory. For example, if there is a portion with high reflectance on the measurement surface b, the brightness in this portion will be higher and will appear as a maximum value on the brightness distribution. Therefore, portions with different brightness on the measurement surface b are extracted by the brightness distribution calculation and the center of gravity calculation based on the result.

[0011] The brightness distribution calculation and gravity center calculation will be explained in more detail as follows. In Figure 2,
The concept of brightness distribution calculation and gravity center calculation in the present invention is illustrated. As shown in this figure, in the present invention, when a trajectory c is formed by the fan beam on the measurement surface b, this trajectory c is traversed by the scanning line d. The scanning line d is a scanning line related to the imaging means B. At the point where the scanning line d crosses the beam trajectory c, a change in brightness level is observed near the beam trajectory c, as shown by a single wave-like figure on the right side of the figure. The brightness distribution calculating means C in the present invention applies processing such as sampling to the video information obtained by the photographing means B, and provides information regarding the brightness level to the center of gravity calculating means D. In other words, by sequentially performing operations by the photographing means B, the brightness distribution calculating means C provides the center of gravity calculating means D with information regarding changes in the brightness level along the beam trajectory c.

The center of gravity calculation means D calculates the center of gravity based on the information given from the brightness distribution calculation means C. This center of gravity is
As shown by e in FIG. 2, it occurs at different points depending on the scanning position of the photographing means B. That is, measurement surface b
When the beam locus c draws a certain curve depending on the unevenness of the beam, the center of gravity e related to the photographing result of the photographing means B occurs at different positions accordingly.

The center of gravity e obtained in this way is subjected to a threshold value judgment in the significance judgment means E. That is, the brightness at the center of gravity e is compared with a predetermined threshold. For example, if it exceeds a threshold value, it is determined that the center of gravity e has significance. In other words, it is confirmed that there are certainly areas with different brightness along the beam trajectory c on the measurement surface b, and the influence of noise etc. is eliminated. After it is confirmed that there is significance in this way, the significant signal processing means G executes predetermined processing such as setting a reference position for measurement by the optical sectioning method. Note that if the significance determining means E determines that the brightness level is not significant, the unevenness of the measurement surface b is determined according to the same algorithm as the conventional light cutting method.

[0014] In this way, in the present invention, information regarding the brightness of the beam trajectory is effectively utilized.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. Note that the same components as those of the conventional example shown in FIGS. 7 and 8 are denoted by the same reference numerals, and the description thereof will be omitted.

FIG. 3 shows the configuration of an unevenness measuring device according to an embodiment of the present invention. The apparatus shown in this figure includes an oscillator 12 that irradiates a fan beam onto the surface 10 of an object to be measured, and a drive control device 16 that drives and controls the oscillator 12. That is, the oscillator 12 is controlled by the drive control device 16.
is driven, and a fan beam is emitted by an oscillator 12, which is, for example, a laser light source.

The apparatus according to this embodiment also includes a camera 14 for photographing a beam trajectory and a processing device 18 for processing video information obtained by the camera 14. The camera 14 photographs the beam locus obtained by the fan beam as in the conventional case, and supplies the image obtained by photographing to the processing device 18. The processing device 18 performs unevenness calculation using a conventionally known light cutting method based on the information obtained by the camera 14;
and performs calculations such as brightness distribution according to the features of the present invention.

FIG. 4 shows the flow of operation of this embodiment. In this embodiment, when video information about the surface 10 of the object to be measured is obtained by the camera 14, this information is supplied to the processing device 18 as a video signal. In the processing device 18, quantization is performed by a built-in 8-bit A/D converter (200).

Next, the processing device 18 calculates the center of gravity 2.
02 is executed. That is, the data obtained in step 200 has a maximum value near the beam trajectory 100. In step 202, the centroids are determined for n pixels in the vicinity of this maximum value. This center of gravity is
This corresponds to the point where the scanning line of the camera 14 crosses the beam trajectory 100. That is, when the scanning line crosses the beam locus 100 on the surface of the object to be measured 10 when the camera 14 takes a picture, the brightness of the image obtained by the picture has a peak at this point. In this embodiment, the center of gravity of this peak (maximum value) is regarded as a point that crosses the beam trajectory 100.

Next, the power level at the position of the center of gravity determined in step 202 is determined (204).
). That is, the brightness level at the point where the scanning line crosses the beam trajectory 100 is determined. The brightness level obtained in this way is compared with a specified value in the subsequent step 206.

In step 206, step 20
The power level determined in step 4 is compared with a predetermined specified value. As a result of this comparison, if the former exceeds the latter, predetermined significant signal processing 208 is executed, otherwise coordinate determination 210 of the trajectory 100 is executed. The significant signal processing 208 referred to here is, for example, processing such as setting the start position of unevenness measurement. After step 210 is executed, the process returns to step 200 and continues the process.

The operation of step 206 is to determine whether the brightness level at the intersection of the scan line and beam trajectory 100 is significant. That is, the object to be measured 1
If a part of the surface of 0 has been treated with paint, etc., and the reflectance of the light beam has increased, when this area is irradiated with a fan beam, other paint etc. have not been applied. This results in a higher brightness level than the other parts. Step 206 corresponds to determining whether the brightness level of the center of gravity obtained in step 204 has been subjected to painting or other treatment at that center of gravity. Therefore, the significant signal processing in step 208 is a process that should be performed when the surface 10 of the object to be measured is painted or the like and the apparatus of this embodiment detects this. Specifically, this is processing such as setting a later measurement start position.

Further, step 210 is a step executed when it is determined in step 206 that the brightness level is not significant, as described above. This step is performed to measure the irregularities on the surface 10 of the object to be measured, which is the original purpose of the apparatus of this embodiment. That is, when measuring unevenness using the optical cutting method, the position of the beam trajectory 100 must be determined. Step 2
10 is a step for this purpose.

FIGS. 5 and 6 show the configuration and operation of a road surface unevenness measuring device using the device of this embodiment. As shown in FIGS. 5(a) and 5(b), when the device according to this embodiment is mounted on the rear of a vehicle 20 and the vehicle 20 is run at a predetermined speed, the surface of the object to be measured is Information regarding the unevenness of the surface (in this case, the road surface) 10 is obtained by the optical cutting method. That is, FIGS. 6(a) to (
If a concave portion 300 due to so-called rutting occurs as shown in the right half of c), this can be detected as a distortion of the beam trajectory.

Furthermore, if the road surface 10 is painted with a warning mark, crosswalk paint, etc., the maximum value of brightness occurs due to this painting, as shown in the left half of FIG. 6(c). This can be determined by detecting the center of gravity according to the feature of this embodiment. Therefore, it is possible to perform predetermined significant processing, such as detecting a crosswalk and setting a road surface unevenness measurement start position in accordance with this detection.

[0026]

[Effects of the Invention] As explained above, according to the present invention,
While measuring road surface irregularities using the light cutting method, significant signal processing is performed by determining the center of gravity of the luminance distribution on the beam trajectory and determining the threshold value. If there are parts with different brightness, it becomes possible to execute a predetermined process in accordance with this. That is, information regarding the brightness distribution in the beam trajectory can be effectively utilized, and a device with higher functionality can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of an unevenness measuring device using optical cutting according to the present invention.

FIG. 2 is a diagram showing the effects of brightness distribution and gravity center calculation in the present invention.

FIG. 3 is a perspective view showing the configuration of an unevenness measuring device using optical cutting according to an embodiment of the present invention.

FIG. 4 is a flowchart showing operations related to threshold determination of the center of gravity of the luminance distribution in the present embodiment.

FIG. 5 is a diagram showing the configuration when this embodiment is applied to a road surface unevenness measuring device, FIG. 5(a) is a diagram showing the side surface of the vehicle body, and FIG. 5(b) is a diagram showing the rear surface of the vehicle body. be.

6 is a diagram showing operations related to road surface unevenness detection and road surface paint detection in the road surface unevenness measuring device of FIG. 5; FIG.
6(a) is a plan view of the road surface, FIG. 6(b) is a side view of the road surface, and FIG. 6(c) is a diagram showing an image obtained by a camera.

7A and 7B are diagrams illustrating the principle of unevenness measurement using a light cutting method; FIG. 7A is a diagram of the operating principle of the apparatus, and FIG. 7B is a diagram of an image taken by a camera.

8 is a diagram showing the principle of the light cutting method shown in FIG. 7 in more detail, FIG. 8(a) is a front view, FIG. 8(b) is a side view, and FIG. 8(c) is a camera image diagram. It is.

[Explanation of symbols]

A Irradiation means B Photography means C Brightness distribution calculation means D Center of gravity calculation means E Significance determination means F　Concave/convex calculation means G Significant signal processing means a Beam ray b Measurement surface c Beam trajectory d Scanning line e Center of gravity 10 Surface of the object to be measured (road surface) 12 Oscillator 14 Camera 16 Drive control device 18 Processing equipment 100 Fan beam trajectory

Claims (1)

[Claims] 1. An irradiation means for irradiating a measurement surface with a fan-shaped beam, a photographing means for photographing the measurement surface to obtain image information related to the beam trajectory, and a luminance on a scanning line crossing the beam trajectory from the image information. brightness distribution calculation means for calculating the distribution;
A center of gravity calculating means for calculating the center of gravity near the maximum value of the luminance distribution, a significance determining means for determining whether the maximum value is significant by comparing the luminance at the center of gravity with a predetermined threshold value, and a means for determining whether the maximum value is significant by comparing the luminance at the center of gravity with a predetermined threshold value. It is equipped with an unevenness calculating means for calculating the unevenness of the measurement surface based on the image information when it is determined to be significant, and a significant signal processing means for executing predetermined significant signal processing when it is determined that it is significant. 1. An unevenness measuring device using optical cutting, which is characterized in that when a portion of paint or the like with different brightness exists on a measurement surface of a surface of the object, the device detects this and executes significant signal processing such as setting a reference position.