JP2007057498A - Laser topography observation system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To measure performance of a reflecting section 2 with a small error; and to maintain observation accuracy of topographic variation. <P>SOLUTION: A reflectivity monitoring section 4 measures reflectivity of the reflecting section 2. By such a constitution, the reflectivity monitoring section 4 can detect degradation with time or fall/loss of the reflecting section 2, so that the observation accuracy of topographic variation can be maintained. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a laser landform observation system that observes a landform change using laser light.

Conventionally, there has been known a laser landform observation system that observes a landform change by installing a reflector on a measurement object such as the ground or a rock wall, irradiating the reflector with a laser beam, and monitoring the reflected light from the reflector. According to such a laser landform observation system, it is possible to perform a risk prediction such as a landslide or a landslide based on the observation result.
JP 2000-1331063 A

  However, according to the conventional laser topographic observation system, once the reflector is installed, it is left as it is during the observation period. May not be maintained.

  The present invention has been made to solve the above problems, and an object of the present invention is to provide a laser landform observation system capable of maintaining the observation accuracy of landform change.

  In order to solve the above-described problems, a laser topography observation system according to the present invention includes a reflection unit that reflects a laser beam provided on the ground surface, and irradiates the reflection unit with a laser beam, and reflects the reflected light from the reflection unit. The laser distance measurement part which measures the distance to a reflection part by light-receiving, and the monitoring part which measures the reflectance of a reflection part are provided.

  According to the laser terrain observation system according to the present invention, the monitoring unit can detect deterioration with time, drop, and disappearance of the reflection unit, so that the observation accuracy of terrain change can be maintained.

  Hereinafter, a configuration of a laser landform observation system according to an embodiment of the present invention will be described with reference to the drawings.

  As shown in FIG. 1, a laser topography observation system according to an embodiment of the present invention includes a reflection unit 2 formed by applying a reflective paint on the surface of a measurement target 1 such as the ground or a rock wall, and a reflection unit 2. The laser distance measuring device 3 that measures and records the distance to the reflecting portion 2 by irradiating the laser beam and receiving the reflected light from the reflecting portion 2, and before or after the distance measurement by the laser distance measuring device 3 And a reflectance monitoring unit 4 for monitoring the change in reflectance of the reflecting unit 2 at the main part, and a change in topography is observed based on the distance measured by the laser distance measuring device 3.

  As shown in FIG. 2, the reflectance monitoring unit 4 includes a reflected light receiving unit 11 that receives reflected light from the reflecting unit 2, and a light amount value measurement that measures the amount of reflected light received by the reflected light receiving unit 11. And a determination unit 13 for determining whether or not the light amount of the reflected light measured by the light amount value measurement unit 12 is within a predetermined range, and transferring the determination result to the laser distance measuring device 3. The apparatus 3 records the determination result transferred from the determination unit 13 in association with the measurement result of the distance to the reflection unit 2. As a result, the operator can analyze the measurement result in consideration of the change in the reflectance of the reflector 2 and maintain the observation accuracy of the topographic change.

  Here, the determining unit 13 determines the amount of reflected light Qmax when the reflectance R of the reflecting unit 2 is maximum (R = Rmax) and the minimum reflectance necessary for maintaining the observation accuracy by reducing the reflectance R. A map showing the relationship between the light quantity Q of reflected light and the reflectance R of the reflector 2 as shown in FIG. 3, which is created by previously measuring the quantity of reflected light Qmin at the time of (R = Rmin) by experiments. Is remembered. Then, the determination unit 13 refers to this map to determine whether or not the light quantity Q of the reflected light is within the specified range, so that the reflectance of the reflection unit 2 is within the range necessary for maintaining observation accuracy. It is determined whether or not there is.

  As is apparent from the above description, in the laser landform observation system according to the embodiment of the present invention, the reflectance monitoring unit 4 measures the reflectance of the reflecting unit 2. According to such a configuration, the reflectance monitoring unit 4 can detect deterioration with time and drop / disappearance of the reflecting unit 2, so that it is possible to maintain the observation accuracy of the topographic change. Further, since the reflectance monitoring unit 4 directly measures the performance of the reflection unit 2, the performance of the reflection unit 2 can be measured with a small error.

  In the present embodiment, the reflectance monitoring unit 4 includes the reflected light receiving unit 11. However, as shown in FIG. 4, the reflectance monitoring unit 4 receives light received on the laser distance measuring device 3 side. The reflected light may be received using the unit 3. According to such a configuration, a conventional laser topography observation system can be used and a laser topography observation system can be configured with a small number of parts.

  In the present embodiment, the light quantity of the reflected light from the reflecting unit 2 is measured by directly receiving the reflected light. However, as shown in FIG. 5, the imaging element 31 that captures an image of the reflecting unit 2. May be provided on the reflectance monitoring unit 4 side, and the amount of reflected light from the reflection unit 2 may be measured using an image captured by the image sensor 31. According to such a configuration, it is possible to monitor the change in the reflectance of the reflecting portion 2 regardless of the defect or failure of the laser distance measuring device 3.

  In this embodiment, the observation accuracy is maintained by determining whether or not the amount of reflected light is within a predetermined range. However, as shown in FIG. An element 31 and a reflection portion shape measurement unit 41 that measures the shape of the reflection unit 2 based on an image captured by the image sensor 31 are provided, and the determination unit 13 determines whether the area of the reflection unit 2 is within a predetermined range. By determining whether or not, the observation accuracy may be maintained. According to such a configuration, it is possible to detect an indication of a decrease in the amount of light before the amount of reflected light falls below a specified value.

  In this case, the determination unit 13 determines the area Smax of the reflection unit 2 when the reflectance R is maximum (R = Rmax) and the minimum reflectance necessary for maintaining the observation accuracy by reducing the reflectance R. The relationship between the area S of the reflecting portion 2 and the reflectance R of the reflecting portion 2 as shown in FIG. 7 is created by measuring the area Smin of the reflecting portion 2 at the time (R = Rmin) in advance by experiments. I remember the map. Then, the determination unit 13 refers to this map to determine whether the area S of the reflection unit 2 is within the specified range, so that the reflectance of the reflection unit 2 is within the range necessary for maintaining observation accuracy. It is discriminated whether or not there is.

  Moreover, in this embodiment, as shown in FIG. 8, by providing the reflective paint coating device 5 and determining that the reflectance and area of the reflecting unit 2 are not within the specified range, the reflectance monitoring unit 4 increases the observation accuracy. When it is determined that it cannot be maintained, the reflective paint application device 5 may be used to apply the reflective paint to the reflecting portion 2. In this case, as shown in FIG. 9, the reflective paint coating device 5 fills a ball-shaped container 51 that is destroyed when an impact of a predetermined value or more is applied, and the container 51 collides with the reflecting portion 2. By doing so, the reflective paint can be applied to the reflective portion 2.

  Further, in the present embodiment, as the reflective paint constituting the reflective portion 2, a surface sample of the ground or rock wall to be measured is collected, and the surface roughness of the ground or rock wall is measured based on the surface sample, It is recommended to use a transparent bead mixed with a reflective paint as a retroreflective material having a diameter of at least twice the measured surface roughness. According to such a structure, it can prevent that the reflectance of the reflection part 2 falls by reflection coating entering into the unevenness | corrugation of the ground or a rock wall.

  As mentioned above, although embodiment which applied the invention made by the present inventors was described, this invention is not limited by the description and drawing which make a part of indication of this invention by this embodiment. That is, it should be added that other embodiments, examples, operation techniques, and the like made by those skilled in the art based on the above-described embodiments are all included in the scope of the present invention.

It is a schematic diagram which shows the structure of the laser landform observation system used as embodiment of this invention. It is a block diagram which shows the internal structure of the reflectance monitoring part shown in FIG. It is a figure which shows the relationship of the light quantity of the reflected light from a reflection part with respect to the reflectance of a reflection part. It is a block diagram which shows the internal structure of the application example of the reflectance monitoring part shown in FIG. It is a block diagram which shows the internal structure of the application example of the reflectance monitoring part shown in FIG. It is a block diagram which shows the internal structure of the application example of the reflectance monitoring part shown in FIG. It is a figure which shows the relationship of the area of a reflection part with respect to the reflectance of a reflection part. It is a block diagram which shows the structure of the application example of the laser landform observation system shown in FIG. It is a figure which shows an example of a structure of the reflective coating material coating device shown in FIG.

Explanation of symbols

1: Measuring object 2: Reflecting unit 3: Laser distance measuring device 4: Reflectance monitoring unit 5: Reflective paint coating device

Claims (3)

A laser topography observation system that observes changes in topography using laser light,
A reflection part provided on the ground surface for reflecting the laser beam;
A laser distance measuring unit that measures the distance to the reflecting unit by irradiating the reflecting unit with laser light and receiving the reflected light from the reflecting unit;
A laser topography observation system comprising: a monitoring unit that measures the reflectance of the reflection unit. The laser landform observation system according to claim 1,
The said monitoring part measures the reflectance of the said reflection part using the light quantity of the reflected light from the said reflection part, The laser landform observation system characterized by the above-mentioned. The laser landform observation system according to claim 1 or 2,
A laser topography observation system, comprising: a reflective coating application unit that applies a reflective coating to the reflective unit when the reflectance measured by the monitoring unit is equal to or less than a predetermined value.

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