JPH04346010A - Track inspecting apparatus - Google Patents

Abstract

PURPOSE:To enhance the contrast of the image of the edge part of an object to be inspected higher than other image photographing regions on a track when the image of the object to be inspected on the track of a railroad is photographed from a running rolling stock. CONSTITUTION:A pair of rod-shaped stroboscopes 5a and 5b are provided as lighting means for emitting illuminating light for a TV camera 4 for obtaining the image on a track. The rod-shaped stroboscopes 5a and 5b are arranged in the longitudinal direction of a rail 11. The TV camera 4 is arranged at the inner central part of a pair of the stroboscopes. A transmitting means 1 for irradiating the track with an energy beam and a receiving means 2 for receiving the energy beam which is reflected from the track are arranged at the opposite sides, respectively, with the TV camera 4 in-between.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to track inspection for inspecting tracks laid on the ground from a running track vehicle, and more specifically, the present invention relates to track inspection for inspecting tracks laid on the ground from a running track vehicle. The present invention relates to a trajectory inspection device that takes images of an object.

0002

2. Description of the Related Art Railway tracks are generally used under harsh conditions, so track management is essential to maintain safe running of vehicles, and it is necessary to monitor all structures on the tracks. Conventional track inspections involve humans actually walking on the tracks visually or using measuring instruments, with the exception of some examples such as track deviation inspections such as rail gauge, level, height, flatness, etc. It was carried out by

0003

[Problems to be Solved by the Invention] However, the conventional measuring method as described above has a problem in that it requires a great deal of effort and time because a person walks on a track.

The present invention has been made in view of the above, and provides a track inspection device capable of photographing only necessary inspection objects from a running vehicle and inspecting a track based on the photographed images. The purpose is to

[0005]

[Means for Solving the Problems] For the above purpose, the present invention includes a transmitting means for irradiating an energy beam onto an orbit;
a receiving means for receiving an energy beam reflected from the orbit; a detecting means for detecting the presence of a specific structure on the orbit from a signal received by the receiving means; and a detecting means for detecting the presence of a specific structure on the orbit by the detecting means. A trajectory inspection device is employed which has an imaging means for capturing an image on the orbit based on a signal indicating that an object is detected, and an illumination means for supplying illumination light for the imaging means. And the lighting means:
The dark-field illumination means has a pair of light-emitting parts, and the pair of light-emitting parts are arranged in the longitudinal direction of the rail, and the imaging means is arranged at the inner center of the dark-field illumination means, and the transmitting means and The receiving means are arranged on opposite sides of the imaging means.

[0006]

[Operation] In the present invention as described above, an energy beam is irradiated onto a structure on orbit, and an energy beam reflected from the orbit is received. The detection means detects that the received signal from the reflected energy beam from the orbit is from a specific structure, thereby detecting the presence of the specific structure on the orbit. Then, based on this detection signal, an image of the object to be inspected on the orbit is taken by the imaging means and the dark field illumination means. The specific structure on the orbit detected by the detection means and the inspection object photographed as an image need to have a substantially constant positional relationship, and may be the same structure. That is, for example, by detecting the rail gap, it is possible to photograph the rail gap itself as an object to be inspected, and it is also possible to photograph the rail gap itself as an object to be inspected. It is also possible to photograph the object as the object to be inspected.

For this reason, even if there are a large number of objects to be inspected randomly on the track and a vehicle equipped with a track inspection device is running at high speed, the objects to be inspected may be a specific structure on the track. As long as the object is in a certain positional relationship, it is possible to reliably capture images of all objects to be inspected. The quality of the object to be inspected can be automatically determined by passing the photographed image through an image processing device on the spot or after taking it home, and humans can also determine the quality of the object by looking at the photographed image. You can.

Further, in an embodiment of the present invention, a pair of rod-shaped strobes are arranged outside the transmitting means for irradiating the energy beam and the receiving means for receiving the reflected energy beam from the orbit, and By setting a large opening angle between the strobe and the pair of rod-shaped strobes, the object to be inspected on the orbit is illuminated with dark field illumination. Then, an image of the object to be inspected on the orbit is taken by the imaging means. The contrast of the edge of the object to be inspected on the orbit photographed by the imaging means is increased by dark field illumination compared to other photographed areas, so the size of the object to be inspected on the orbit is calculated by image processing. It is possible to increase processing speed.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be explained below based on the illustrated embodiments. This embodiment relates to the inspection of rail joint gaps, and shows an apparatus that automatically takes images of the joint gaps from a running vehicle.

FIG. 1 is a cross-sectional view showing the structure of an embodiment of the present invention, and shows a schematic structure cut in a direction parallel to the extending direction of the rail.

FIG. 2 is a plan view clearly showing the arrangement of the main parts of the structure shown in FIG. 1.

The entire device is mounted on the bottom or side of a moving vehicle 20. A laser beam emitted toward the rail 11 from the transmitting means 1 is reflected by the surface of the rail 11 and then received by a photodetector of the receiving means 2. As shown in FIG. 3, which is a plan view seen from the top of the rail, the laser beam 12
is irradiated onto the rail 11 by an optical system within the transmitting means as a slit-shaped light beam extending in a direction perpendicular to the rail extension direction. As the vehicle travels, the laser beam 12 sequentially scans the rail 11, and when the vehicle crosses the joint gap 13, the reflected light from the rail is temporarily cut off, and the reflected light is received by the receiving means 2. The strength is temporarily reduced. The rail joint gap 13 is detected by detecting this temporary decrease in the amount of received light by the detection means 3.

Next, the detection signal of the seam gap 13 obtained by the detection means 3 is transmitted to a TV camera 4 corresponding to an imaging means and a pair of rod-shaped strobes 5 corresponding to an illumination means.
By inputting information to a and 5b, an image of the rail joint gap 13, which is the object to be inspected, is automatically photographed. However, if the image of the seam gap and the laser beam are simultaneously photographed by the TV camera, this will affect the accuracy of the gap measurement, so the laser beam must be turned off during the photographing, or the wavelength filter 10 must be installed in front of the TV camera 4. By doing so, the laser beam can be cut. If, for example, an infrared semiconductor laser is used as the laser beam 12 and a wavelength filter 10 that cuts this infrared wavelength is selected, clear images can be obtained without reducing the amount of illumination light in the visible region necessary for photographing the free space image. You can get an image of the play area.

Here, as shown in FIGS. 1 and 2, the TV camera 4 is arranged at the center inside the pair of rod-shaped strobes 5a and 5b, and the transmitting means 1 and the receiving means 2 are arranged between the pair of rod-shaped strobes 5a and 5b. They are placed on opposite sides of the TV camera 4 inside the TV camera 5b. With this arrangement, it is possible to construct a device that emphasizes the following functions. By arranging the rod-shaped strobes 5a and 5b in the rail extension direction and by setting a large opening angle between the pair of rod-shaped strobes 5a and 5b relative to the inspection object on the track, the object to be inspected on the track is darkened. The field of view is illuminated. That is, the edge portion of the inspection object on the trajectory to be imaged is illuminated more brightly than other imaging areas. This will be explained in detail. FIG. 4 shows a photographing area of the TV camera 4 as a photographing means. In order to shorten the image processing time of the subject photographed by the TV camera 4, the TV camera 4 is arranged so that the scanning line direction of the TV camera 4 coincides with the rail extension direction. Since the entire device is mounted on the bottom or side of a running vehicle, vibrations, lateral vibrations, etc. of the vehicle occur in a direction perpendicular to the rail extension direction. In order to improve image processing accuracy, it is necessary to enlarge the object to be photographed as much as possible, but in this case, the object to be measured may come off the screen due to vehicle vibration or lateral vibration. Therefore,
In order to avoid missing shots of subjects due to vibrations, lateral shakes, etc., vehicle vibrations, lateral shakes, etc. are taken into consideration in the photographing area of the TV camera 4.

When the width of the rail is W, the maximum lateral displacement of the object to be measured is X, and the length of the photographing area of the TV camera 4 in the direction perpendicular to the rail extension direction is L, the following equation holds true. . L=W+2X
(1)

If the length of the photographing area of the TV camera 4 in the direction perpendicular to the rail extension direction is L, the length of the photographing area in the rail extension direction is equal to the length L in the vertical direction and the aspect ratio constant of the screen. It is multiplied by a, and its length becomes aL.

FIG. 5 shows the arrangement of the illumination means consisting of a pair of light sources 5a and 5b. In the same figure, 5c, 5d
is the light source 5 when the surface of the rail 11 is assumed to be a mirror surface.
A and 5b are virtual images, and a TV camera 4 is used as a photographing means.
When the half angle of view of the photographing range is θ1, and the distance from the TV camera 4 to the surface of the rail 11 is R, the following equation holds true. θ1 = arctan(aL/2R)
(2)

If the opening angle that the virtual images 5c and 5d of the light sources 5a and 5b have with respect to the TV camera 4 is θ2, then in this illumination means, θ2 is the shooting angle of view 2θ1 of the TV camera 4.
The light sources 5a and 5b are arranged so as to be larger. That is, θ2 > 2θ1
By satisfying the condition (3), the specularly reflected light from the rail surface will not enter the TV camera, and only the scattered light from the edges such as rail joint gaps will enter, resulting in good dark field illumination. .

A TV camera 4 is installed in the center of the lighting means.
By arranging this, it is possible to photograph this illuminated photographing area from directly above. On the other hand, transmitting means 1
The optical axis direction of the laser beam emitted from the receiving means 2 and the optical axis direction of the laser beam incident on the receiving means 2 are in a relationship of regular reflection with respect to the rail surface as shown in FIG. can be efficiently received. In addition, the transmitting means 1
Since the laser beam irradiated onto the rail by is located near the center of the area of the rail photographed by the TV camera 4, after the seam gap is detected by the detection means 3,
If the time required for the TV camera 4 to capture the rail image is sufficiently short, the seam gap will be captured approximately at the center of the screen, regardless of the speed of the traveling vehicle. The fact that the images between the seams are always taken from directly above and in the center of the screen means that it takes less time to search for the image location than when the images are in different positions each time. Since there is no image processing, the subsequent image processing process can be simplified.
The overall image processing time can be shortened.

Further, the transmitting means 1 and the receiving means 2 are shown in the plan views of FIGS. 6A and 6B as seen from the top of the rail, and the slit-shaped light beam formed on the rail surface by the transmitting means 1. As shown in FIGS. 7(A) and 7(B), the laser beam 12 is transmitted onto the surface of the rail 11 by an optical system (consisting of a laser light source 14, a collimator 16, and a cylindrical lens 17) within the transmitting means 1. It is irradiated as a slit-shaped light beam extending in a direction perpendicular to the rail extension direction. Examples of arranging the transmitting means 1 and the receiving means 2 include arranging them in the rail extension direction as shown in FIG. 6(A), and arranging them on opposite sides across the rail 11 as shown in FIG. 6(B). There are two possible cases. In the case of the arrangement shown in FIG. 6(B), the optical system (laser light source 14, collimator 16, cylindrical lens 17,
), a slit-shaped light beam (laser light 12
) is formed at an angle with respect to the surface of the rail 11, so that the width of the slit-shaped light beam increases as a whole, which becomes a factor in lowering the detection efficiency of the seam gap 13. On the other hand, in the case of FIG. 6(A), as shown in FIG. 7(A), since the slit-shaped light beam (laser light 12) is imaged on the rail 11 surface without tilting, the slit-shaped light beam width is Since it is thin and almost uniform, it is a small factor that lowers the detection efficiency of the seam gap 13. Therefore, it is effective to arrange the transmitting means 1 and the receiving means 2 in the rail extension direction as shown in FIG. 6(A).

Note that the slit-shaped light beam projected onto the rail surface in order to detect the rail joint gap 13 is also received in the same way as the shooting range of the TV camera 4 is determined based on the amount of vibration and lateral shake of the vehicle. It is desirable that the length of the slit-shaped light beam is such that the amount of light received by the means 2 does not decrease due to the amount of vibration or lateral vibration of the vehicle.

In this embodiment, the TV camera 4
In order to protect the transmitting means 1, receiving means 2, etc. from dust, water droplets, etc., the entire device is housed in a housing 7, and the reflection and incidence of the laser beam and the photographing of images between the rail joints are performed using a transparent window. It is carried out through 8. As shown in FIG.
There is a sunshade cover 9 that surrounds and extends downward. This cover works as follows. The reason why a strobe is used in this embodiment is that its light emission time is sufficiently short and its light emission intensity is sufficiently strong, so that it is possible to take a blur-free seam gap image even from a vehicle traveling at high speed. However, if the rail portion of the object to be photographed is exposed to direct sunlight, and if the illuminance is equal to or higher than the contribution from the strobe, it may cause blur in the seam gap image. Therefore, it is necessary to block direct sunlight hitting the rail portion to be photographed, and this is done by the cover 9. However, the sunshade cover 9 is also provided on a surface on the vehicle side parallel to the extending direction of the rail.

In this embodiment, in order to obtain a still image, a strobe light source that instantaneously illuminates the rail based on a seam gap detection signal was used as dark field illumination means consisting of a pair of bar-shaped strobes. It is not limited to this. A still image is obtained by using a bar-shaped light source as a point light source, or a bar-shaped and point light source that illuminates continuously, using a TV camera with a high-speed shutter, and inputting a detection signal between seam gaps to the high-speed shutter TV camera. You can do it like this. However, in this case, in order to obtain a still image sufficient for measuring the clearance value, the shutter speed of the TV camera needs to be sufficiently short with respect to the traveling speed of the vehicle. The image of the seam gap thus obtained is recorded in the image memory 6. By passing this image through an image processing device either on the spot or after taking it home, the gap value can be automatically measured. Furthermore, by viewing this image, a human can make a rough judgment of acceptability.

By the way, when measuring the rail clearance value, it is necessary to measure the rail temperature at the same time, and if a radiation thermometer is used, the temperature can be measured without contact in parallel with the joint clearance image shooting. . FIG. 8 shows a cross-sectional view in a plane perpendicular to the extending direction of the rail. As shown here, radiation thermometers 15, 15' are arranged on both sides of the casing 7 housing the track inspection device described above. These radiation thermometers 15, 15' are connected to the rail 11' on the opposite side.
, 11. The temperature of each side is measured. The reason for measuring the temperature on the side surface of the rail is that since the top surface of the rail is close to a mirror surface, the emissivity is almost zero, making accurate measurement impossible. With this arrangement, the entire device including the radiation thermometer can be configured compactly. In addition, input the seam clearance detection signal to the radiation thermometer,
If you measure the temperature, when measuring the gap between each seam,
It is possible to obtain the rail temperature corresponding to that location.

In the above description, the rail joint gap inspection has been described, but the track inspection device of the present invention is not limited to this, but can also be used for inspecting rail joint plates, rail fastening devices, etc. can do. In addition, although an optical configuration has been shown to detect a specific structure on orbit, it is not limited to this, and other methods such as ultrasonic waves may be used to detect a specific structure on orbit. Energy beams may also be used.

[0026]

Effects of the Invention According to the orbit inspection device of the present invention as described above, an energy beam is irradiated onto an orbit, an energy beam reflected from the orbit is received, and based on this received signal, the orbit is identified. The system detects the presence of structures on the track and captures an image of the object on the track, so as long as the object is in a certain positional relationship with a specific structure on the track, the object on the track will be detected. Even if there are a large number of objects to be inspected at random and the vehicle equipped with the track inspection device is traveling at high speed, images of all the objects to be inspected can be reliably captured.

[0027] The imaging means is disposed at the center inside the dark-field illumination means, and the transmitting means and the receiving means are disposed inside the dark-field illumination means on opposite sides of the imaging means. Accordingly, the detection rate and inspection accuracy of objects to be inspected on the orbit can be improved.

[0028] By installing such a track inspection device on a running vehicle and performing track inspections, many track inspections can be performed accurately in a short period of time, making track maintenance management much more efficient than before. can be converted into

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the configuration of an embodiment of the present invention, and shows a schematic configuration taken in a direction parallel to the extending direction of the rail.

FIG. 2 is a plan view clearly showing the arrangement of main parts of the configuration shown in FIG. 1;

FIG. 3 is a plan view showing how rail joint gaps are detected using a laser beam.

FIG. 4 is an explanatory diagram of the photographing area of the TV camera in FIG. 1;

FIG. 5 is an explanatory diagram of the arrangement of dark field illumination means of the present invention.

FIGS. 6A and 6B are plan views illustrating the arrangement direction of the transmitting means and the receiving means with respect to the rail extension direction.

[Fig. 7] (A) and (B) are Fig. 6 (A) and Fig. 6 (B)
FIG. 2 is a schematic diagram illustrating the inclination of a slit-shaped light beam that forms an image near the rail surface, corresponding to the arrangement direction of the transmitting means.

FIG. 8 is a schematic cross-sectional view showing the overall configuration of the device of the present invention having a radiation thermometer.

[Explanation of symbols]

1 Transmitting means 2 Receiving means 3 Detecting means 4 Imaging means 5a, 5b Dark field illumination means 12 Energy beam (laser light) 13 Specific structure (seam gap)

Claims (3)

[Claims] 1. A transmitting means for irradiating an energy beam onto an orbit, a receiving means for receiving an energy beam reflected from the orbit, and a signal received by the receiving means to detect the existence of a specific structure on the orbit. a detection means for detecting a specific structure on the orbit, an imaging means for capturing an image on the orbit based on a signal by which the detection means detects a specific structure on the orbit, and supplying illumination light for the imaging means. In the track inspection device, the illumination means is a dark field illumination means having a pair of light emitting parts, and the pair of light emitting parts are arranged in the longitudinal direction of the rail, and the imaging means is a dark field illumination means having a pair of light emitting parts arranged in the longitudinal direction of the rail. It is arranged at the inner center of the visual field illumination means, and the transmitting means and the receiving means are arranged on opposite sides of the imaging means, respectively.
Track inspection equipment. 2. Assuming that the rail surface is a mirror surface, the aperture angle that each virtual image of the pair of light emitting parts extends with respect to the imaging means is θ2, and the half angle of view of the photographing range of the imaging means is θ1.
The track inspection device according to claim 1, wherein the pair of light emitting parts are arranged so as to satisfy the condition θ2 > 2θ1. 3. The orbit inspection device according to claim 1, wherein the energy beam is a laser beam.