JP2023116855A - Surveying target and measurement method - Google Patents

Abstract

To provide a surveying target capable of continuously capturing an object to be measured by enabling a state of satisfying collimation luminous flux of automatic collimation of a surveying instrument.SOLUTION: A surveying target is provided on a surveying object, is irradiated with light from a surveying instrument, and has a reflection surface that reflects the light. The reflection surface comprises a first reflection portion composed of a retroreflective structure and a second reflection portion composed of the retroreflective structure, having a reflectance lower than the first reflection portion, and having high surveying accuracy. The second reflection portion is provided at a center of the first reflection portion or the first reflection portion is provided at a center of the second reflection portion so that the first reflection portion and the second reflection portion face in the same direction.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to a surveying target and a surveying method, and more particularly to a surveying target suitable for surveying by a surveying instrument having an automatic collimation function.

Conventionally, in geodetic surveying, civil engineering surveying, and architectural surveying, the target position of the object to be measured was captured by a total station or transit telescope, but the emergence of surveying instruments with an automatic collimation function. This makes it easy to capture the target position regardless of the skill level of the operator. In geodetic surveying, civil engineering surveying, and architectural surveying, a target (target) such as a highly reflective sheet or triangular prism is placed at the target position of the object to be measured. It is done by automatically capturing the emitted light. The intensity of the reflected light depends on the angle between the line of sight to the target and the reflecting surface of the reflecting sheet or the prism surface. For example, the automatic collimation angle is limited to about ±20° for a reflective sheet and about ±45° for a triangular prism. For this reason, in recent years, a target device has been developed that is mainly composed of a triangular prism capable of automatic collimation in all directions and at an angle of 360°, as disclosed in Patent Document 1.

JP 2020-98175 A

However, a target device based on a triangular prism capable of automatic collimation is very expensive, has a structure that is easily damaged, and requires careful handling. In addition, since the reflecting sheet and the triangular prism limit the automatic collimation range as described above, it is necessary to change the position of the surveying instrument each time in order to make use of the automatic collimation function. Each time the position of the surveying instrument is changed, operations such as transporting, assembling, and leveling the surveying instrument are required, which hinders continuous acquisition of the object to be measured.
In order to solve the above-mentioned problems, the present invention enables a state in which the collimated luminous flux of the automatic collimation of the surveying instrument is satisfied even if the survey instrument is installed in a wider range of angles of elevation and depression than in the past, so that the object to be measured can be measured continuously. It is an object of the present invention to provide a survey target that can be acquired.

As a configuration of a surveying target for solving the above problems, a flat surveying target provided on a surveying object, irradiated with light from a surveying instrument, and having a reflecting surface for reflecting the light, The surface is composed of a first reflective portion composed of a retroreflective structure, and a second reflective portion composed of a retroreflective structure having a lower reflectance and higher survey accuracy than the first reflective portion. The first reflecting portion and the second reflecting portion face the same direction, and the second reflecting portion is provided at the center of the first reflecting portion, or the first reflecting portion is provided at the center of the second reflecting portion. and
According to this configuration, even if the surveying target is installed in a wider range of elevation and depression than in the past, the collimation constraint of the automatic collimation of the surveying instrument can be satisfied, and the measurement target can be installed in a wide range. It can allow for continuous supplementation of objects.
Further, as a configuration of the target for surveying, it is preferable that the contour shape of the first reflecting portion and the contour shape of the second reflecting portion are point-symmetrical or line-symmetrical.
Further, as another configuration of the surveying target, by providing a mounting means for mounting the surveying target on the back side of the reflecting surface, the installation work of the surveying target can be facilitated. For example, by using a magnet as the attachment means, it is possible to facilitate installation and relocation of the survey target.
In addition, as a surveying method in which the target for surveying according to any one of claims 1 to 4 is attached to an object to be surveyed and surveying is performed using a surveying instrument having an automatic collimation function and an imaging device, the target for surveying from the surveying instrument a first step of collimating the surveying instrument to the target for surveying by an automatic collimation function by irradiating light on and acquiring the light reflected from the first reflecting portion; a second step of acquiring by the imaging device, identifying the position of the second reflecting part by image diagnosis, and collimating the surveying instrument to the second reflecting part of the survey target by an automatic collimation function. It is preferable that the collimation in the second step is used for surveying based on the light reflected from the second reflecting section.
Further, as a surveying method in which the surveying target according to any one of claims 1 to 4 is attached to a surveying object and surveying is performed using a surveying instrument having an automatic collimation function, light is emitted from the surveying instrument to the surveying target. a first step of irradiating, acquiring the light reflected from the first reflecting portion, and collimating the surveying instrument to the surveying target by an automatic collimation function; The position of the second reflecting portion is specified by measuring the difference in the amount of light reflected by the first reflecting portion and the second reflecting portion from the reflected light as reflected light reflected from the reflecting portion and the second reflecting portion, and a second step of collimating the surveying instrument to the second reflecting section by an automatic collimation function, and the collimation in the second step may measure based on the light reflected from the second reflecting section.
By surveying in this way, even if the survey target is installed in a wider range of elevation and depression than before, it is possible to satisfy the collimation constraint of the automatic collimation of the surveying instrument, and the target can be installed in a wide range. The object to be measured can be continuously captured.

It is a schematic diagram showing an example of the target for surveying concerning this embodiment. It is a cross-sectional schematic diagram which shows an example of the retroreflective structure which has a prism structure. FIG. 4 is a schematic diagram showing another form of the surveying target;

Hereinafter, the present invention will be described in detail through embodiments of the invention, but the following embodiments do not limit the invention according to the claims, and all combinations of features described in the embodiments are It includes configurations that are not necessarily essential to the solution and are selectively adopted.

FIG. 1 is a schematic diagram of a surveying target according to this embodiment. A surveying target (hereinafter simply referred to as a target) 1 is attached to a structure such as a pillar or a steel frame that is an object to be measured. Note that the object to be measured is not limited to structures such as columns and steel frames.

As shown in FIG. 1, a surveying target (hereinafter simply referred to as a target) 1 according to the present embodiment has a flat plate shape, for example, a rectangular (rectangular) shape in plan view. One surface of the target 1 functions as a reflecting surface portion 1a for reflecting the collimated light emitted from the surveying instrument, and the other surface functions as a mounting surface portion 1b for mounting the target 1 on an object to be measured. The reflective surface portion 1a and the mounting surface portion 1b are flat and parallel to each other.

The reflecting surface portion 1a is configured to have two reflecting portions 2; 4 with different reflectances. In the following description, the reflecting portion 2 is called the first reflecting portion 2 and the reflecting portion 4 is called the second reflecting portion 4 . As shown in FIG. 1( a ), in the present embodiment, the second reflecting section 4 has a square shape and is provided in the central portion of the first reflecting section 2 . The fact that the second reflecting section 4 is provided at the central portion of the first reflecting section 2 means that, for example, when the centroid of the first reflecting section 2 is set as a collimation point, the centroid of the second reflecting section 4 is the first. It means that they are arranged so as to match the centroid of the reflecting part 2 .

The first reflecting section 2 and the second reflecting section 4 are each composed of a retroreflective structure. A retroreflective structure refers to a structure capable of reflecting incident light in the direction of incidence. That is, the first and second reflecting portions 2; 4 are configured to reflect the light received from the light source as it is. There are a plurality of retroreflective structures, and examples thereof include a prism structure and a bead structure.

FIG. 2 is a schematic cross-sectional view showing an example of a retroreflective structure having a prism structure. For example, a retroreflective structure made up of a prismatic structure has a base layer 20 with transparent triangular pyramids (prisms) arranged densely in a base layer 22 with the base facing up. By forming a half-mirror layer 24 on the prism-shaped retroreflective surface 22a formed on the lower surface, the light incident from the bottom surface side of the triangular pyramid is reflected by the three surfaces of the prism, so that the light source It is configured to be directed and reflected.

The first reflecting portion 2 and the second reflecting portion 4 are configured to reflect the collimated light incident on the reflecting surface portion 1a in the same incident direction. The first reflecting section 2 is composed of a retroreflecting structure having a higher reflectance and a lower surveying accuracy than the retroreflecting structure forming the second reflecting section 4 . In other words, it can be said that the second reflecting section 4 is composed of a retroreflecting structure having a lower reflectance and a higher surveying accuracy than the retroreflecting structure forming the first reflecting section 2. can be done.

That the first reflecting portion 2 has a higher reflectance than the second reflecting portion 4 or that the second reflecting portion 4 has a lower reflectance than the first reflecting portion 2 means that the first reflecting portion 2 and the second reflecting portion 4 means the relative difference in properties for the reflection of collimated light. Here, the fact that the reflectance of the first reflecting portion 2 is higher than that of the second reflecting portion 4 means, for example, that the incident angle θ (see FIG. 2) of the collimated light emitted from the surveying instrument with respect to the target 1 gradually is greatly changed, even if the retroreflective structure forming the first reflecting section 2 is incident at a larger angle than the retroreflective structure forming the second reflecting section 4, the automatic sighting of the surveying instrument does not occur. It means having the characteristics of being able to reflect with a brightness that satisfies the standard.

In addition, the fact that the second reflecting section 4 has a higher surveying accuracy than the first reflecting section 2 or that the first reflecting section 2 has a lower surveying accuracy than the second reflecting section 4 means that the first reflecting section 2 and the second reflecting section 2 The difference in reflection characteristics from the reflection portion 4 is referred to as a relative relationship. That is, the fact that the second reflecting section 4 has higher surveying accuracy than the first reflecting section 2 means, for example, that the retroreflective structure constituting the first reflecting section 2 and the second reflecting section 4 are formed with the same area. When collimated light is emitted from a surveying instrument with respect to the constituent retroreflective structure, the deviation of the reflected light from the incident light, that is, the deviation δ of the path is small.

For example, in the retroreflective structure having a prismatic structure as shown in FIG. 2, it can be said that the path deviation δ increases as the size of the prisms forming the prism layer 22 increases, and the path deviation δ decreases as the size of the prisms constituting the prism layer 22 decreases. That is, it can be said that the larger the size of the prism, the lower the surveying accuracy, and the smaller the size of the prism, the higher the surveying accuracy. It should be noted that the level of surveying accuracy described here is for the retroreflective structure having the structure shown in FIG. .

As shown in FIG. 1(b), the target 1 is formed by, for example, sticking a reflective sheet forming a first reflective portion 2 and a second reflective portion 4 having a retroreflective structure on one side of the base portion 6. Can be configured. For the base portion 6, for example, a plate material made of resin material, polyethylene material, or the like can be used.
Then, a reflective sheet functioning as the first reflective part 2 is attached to the entire one surface of the base part 6, and a reflective sheet functioning as the second reflective part 4 is further placed on the reflective sheet of the first reflective part 2. , the reflective surface portion 1a of the target 1 can be formed by affixing them so as to overlap each other.
Thus, the target 1 can be configured with a simple structure and can be produced at low cost.

As shown in FIGS. 1(b) and 1(c), the target 1 has been described as one in which a reflecting sheet functioning as the second reflecting section 4 is attached on a reflecting sheet functioning as the first reflecting section 2. , but not limited to.
For example, as shown in FIG. 3, an accommodating portion that can accommodate the second reflecting portion 4 in the first reflecting portion 2 so that the centroid of the second reflecting portion 4 coincides with the centroid of the first reflecting portion 2 . 10 may be provided, and the second reflecting section 4 and the first reflecting section 2 may be integrated. In this case, for example, the incident surface of the retroreflective structure forming the first reflecting section 2 and the incident surface of the retroreflective structure forming the second reflecting section 4 should be flush with each other.

The contour shape of the target 1 (first reflecting portion 2) in a plan view is not limited to the rectangular shape described above, and may be any other point-symmetrical or line-symmetrical shape such as a rectangle, circle, triangle, or rhombus. It can be. In addition, the contour shape of the second reflecting portion 4 in a plan view is not limited to the above-described square shape, and may be any other point-symmetric or line-symmetric shape such as a rectangle, circle, triangle, or rhombus. Also good.

Attachment means (not shown) may be provided in advance on the attachment surface portion 1b so that the target 1 can be attached to the object to be measured. The mounting means may be, for example, an adhesive, an adhesive tape, a magnet, or the like, and may be changed according to the object to be measured. For example, when the object to be measured is a nonferrous material such as a concrete member, a wooden member, or a resin member, an adhesive or an adhesive tape is suitable. For example, when the object to be measured is a magnetic material such as a structural member made of steel, a magnet is suitable, and the target 1 can be easily installed, removed, and diverted.

[How to use Target 1]
A surveying method using the target 1 will be described. The target 1 according to this embodiment is suitable for surveying using, for example, a surveying instrument having an automatic collimation function. In the following description, as an example of a surveying instrument, a surveying method using a surveying instrument having an automatic collimation function and having an imaging device will be described.

As the surveying instrument, for example, a so-called total station or the like that includes a surveying device, an imaging device, an attitude adjustment device, a surveying control device, and a display device can be used.

The surveying unit is equipped with a spirit level and is constructed by combining a theodolite for measuring angles with a light wave range finder. It outputs survey data including the azimuth (horizontal angle, vertical angle) of the sighting point calculated based on the obtained distance and the angle obtained by the theodolite. The survey data can be output to, for example, a survey control device.

The imaging device includes a light receiving unit such as a CCD, for example, the collimation direction of the surveying unit and the optical axis direction of the imaging device are parallel, and the collimation direction of the surveying unit and the image center of the image captured by the imaging device have a predetermined relationship. It is fixed to the surveying unit so that In this embodiment, the collimation direction is adjusted so as to match the center of the image, and the center of the image obtained by the imaging device is set so as to obtain an image corresponding to the collimation direction. The image obtained by the imaging device can be output to the surveying control device in synchronization with the surveying process by the surveying unit, for example.

The attitude adjustment device includes a first motor that rotates the surveying unit and the imaging device around a horizontal axis, a second motor that rotates the surveying unit and the imaging device around a vertical axis, and a motor control unit that controls the driving of each motor. The motor control unit adjusts the direction of the surveying unit so that the sighting direction of the surveying unit matches the center of the target 1 based on a command (signal) input from the surveying control device. The attitude adjustment device may have, for example, an automatic tracking function for automatically tracking the collimation direction with respect to the target 1 .

The surveying control device is a so-called computer having a CPU, memory, input/output means, etc., and executes processing for enabling the automatic sighting function and processing for making the surveying unit collimate the target. Then, the posture adjusting device outputs a command as a signal to the posture adjusting device to adjust the orientation of the surveying unit. The surveying control device may be provided integrally with the surveying unit, or may be provided separately from the surveying unit via wireless or wired communication means.

For example, the automatic collimation function of the surveying instrument is such that the collimating light emitted from the light wave rangefinder in the surveying unit and reflected by the target 1 is received by the light receiving unit of the light wave rangefinder, and the collimating light received by the light receiving unit. is configured based on, it is preferable to configure so as to be processed by the surveying control device as follows. In the following description, when collimating light is emitted, the reflected light from the first reflecting section 2 enables automatic collimation of the surveying instrument, but the reflected light from the second reflecting section 4 enables automatic collimation of the surveying instrument. will be described as a process when the target 1 is provided at a position where it is impossible to

First, the surveying control device emits collimated light from the surveying unit toward the target 1 by the automatic collimation function, and the surveying unit is directed to the target 1 based on the reflected light reflected from the target 1 (first reflecting unit 2). Collimate (step 1). The sighting point collimated at this time is called a temporary sighting point. Also, the temporary sighting point does not need to match the sighting point set for the target 1 .
Next, when collimating in step 1, the reflected light reflected from the target 1 is received by the imaging device, and the obtained image is analyzed by the surveying control device, so that the second reflecting part 4 in the image is located (step 2).
Next, the position (coordinates) of the temporary sighting point when collimating the target 1 in step 1 and the position (coordinates) of the sighting point of the second reflector 4 specified in step 2 are calculated. Calculate (step 3).
Next, in order to correct the displacement of the position calculated in step 3, the surveying unit outputs a command for correcting the collimation point of the second reflecting unit 4 to collimate to the posture adjustment device. Correct the sub-position (step 4).
Next, in step 4, the surveying unit emits collimated light toward the target 1 from the collimated position, and measures the collimated position based on the second reflector 4 (step 5).
As a result, the accurate distance and azimuth (horizontal angle, vertical angle) to the collimation point can be measured.
Then, the distance to the sighting point and the azimuth (horizontal angle, vertical angle) measured in step 5 may be displayed on the display device as survey results.

Here, in the image analysis in step 2, the positions of the four corners of the contour shape (rectangle) of the target 1 are specified by, for example, performing image processing such as pattern matching on the image obtained by the imaging device. , and the intersection of the diagonal lines as the sighting point. In addition, in order to realize the processing of steps 1 and 2, it is required that the contour shape of the target 1, that is, the contour shape of the first reflecting portion 2 is rectangular, and the contour shape of the second reflecting portion 4 is square. Furthermore, information such as their dimensions and the positional relationship of the second reflecting section 4 with respect to the first reflecting section 2 may be stored.

Also, the image analysis in step 2 is not limited to the above pattern matching, and other methods may be used. For example, a program for obtaining the contour shape of the target 1 based on machine learning may be stored in the storage means to obtain the contour shape of the target 1 .

In addition, the automatic collimation function executed by the surveying control device is such that an image obtained by receiving collimation light emitted from the light wave rangefinder in the surveying unit and reflected by the target 1 by the imaging device is captured by the surveying control device. may be a surveying instrument configured to control the attitude adjustment device so that the collimated light and the optical axis of the imaging device are aligned by performing image processing.

If the surveying instrument does not have an imaging device, the surveying control device may be configured to perform the following processing.
First, the surveying control device emits collimating light from the surveying unit by the automatic collimation function, and collimates the surveying unit to the target 1 as reflected light reflected from the target 1 (mainly the first reflecting unit 4) (step 1). ).
Next, assuming that the reflected light when collimated in step 1 is the reflected light reflected from the first reflecting section 2 and the second reflecting section 4, the reflected light reflected from the first reflecting section 2 The position of the collimation point of the second reflector 4 is specified based on the difference in the amount of light reflected from the second reflector 4 (step 2).
Next, the position (coordinates) of the temporary sighting point when collimating the target 1 in step 1 and the position (coordinates) of the sighting point of the second reflector 4 specified in step 2 are calculated. Calculate (step 3).
Next, a command for correcting the positional deviation calculated in step 3 is output to the attitude adjustment device to correct the collimation direction of the surveying unit (step 4).
Next, in step 4, the surveying unit emits collimated light toward the target 1 from the collimated position, and measures the collimated position based on the second reflector 4 (step 5).
As a result, the accurate distance and azimuth (horizontal angle, vertical angle) to the collimation point can be measured.
Then, the distance to the sighting point and the azimuth (horizontal angle, vertical angle) measured in step 5 may be displayed on the display device as survey results.

Note that the process of specifying the position of the collimation point of the second reflecting section 4 based on the difference in the amount of light reflected from the first reflecting section 2 and that reflected from the second reflecting section 4 in step 2. is, for example, the distribution of light received by the light-receiving unit that receives the collimated light (reflected light) emitted from the surveying unit and reflected by the target 1 in the execution of the automatic collimation function, for example, with a predetermined light intensity as a threshold value. It divides into an area considered to have been reflected from the first reflecting part 2 and an area considered to have been reflected from the second reflecting part 4, and the area with the light quantity lower than the threshold value is reflected from the second reflecting part 4. Then, the survey control device may process the map so as to obtain the centroid of the area.

As described above, in the surveying target, the light from the surveying instrument is irradiated, and the reflecting surface for reflecting the light is composed of the retroreflective structure, and the first reflecting section is composed of the retroreflective structure. and a second reflecting portion having a lower reflectance and higher surveying accuracy than the first reflecting portion, wherein the first reflecting portion and the second reflecting portion face the same direction. By providing the second reflecting portion so as to be positioned at the center of the portion, at the time of surveying, first, the surveying instrument is collimated to the approximate position of the target 1 based on the first reflecting portion, and then the second reflecting portion is collimated. By specifying the position of the centroid (sighting point) of the reflection part and correcting the sighting direction of the surveying instrument, the surveying instrument can be automatically operated even if the target 1 is set in a wider range of elevation and depression than before. It can allow a state of fullness of the collimation beam of collimation, allowing continuous acquisition of the measurement object.

In the above embodiment, the second reflector 4 has a lower reflectance and a higher surveying accuracy than the first reflector 2, but the first reflector 2 has a higher Also, the reflectance may be low and the survey accuracy may be high.

Further, in the present embodiment, the target 1 has a flat plate shape, but the shape is not limited to this, and may be changed to a semi-cylindrical shape, for example.

An important point in the present invention is that the target 1 is provided with a plurality of reflecting portions having different reflectances on the reflecting surface portion 1a that reflects the collimated light emitted from the surveying instrument, and the lower the reflectance, the higher the surveying accuracy. It is sufficient if it is configured to be high.

1 surveying target, 1a reflective surface portion, 1b mounting surface portion, 2; 4 reflective portion.

Claims (6)

A surveying target provided on a surveying object, irradiated with light from a surveying instrument, and having a reflecting surface that reflects the light,
The reflective surface is
a first reflecting section configured by a retroreflective structure;
a second reflecting section configured by a retroreflective structure, having a lower reflectance than the first reflecting section and having a higher surveying accuracy;
so that the first reflecting portion and the second reflecting portion face the same direction,
A target for surveying, comprising: the second reflecting portion at the center of the first reflecting portion; or the first reflecting portion at the center of the second reflecting portion. 2. The survey target according to claim 1, wherein the contour shape of the first reflecting portion and the contour shape of the second reflecting portion are point-symmetrical or line-symmetrical. 3. The surveying target according to claim 1, further comprising mounting means for mounting said surveying target on the back side of said reflecting surface. 4. A survey target according to claim 3, wherein said mounting means is a magnet. A surveying method of attaching the surveying target according to any one of claims 1 to 4 to a surveying object and surveying using a surveying instrument having an automatic collimation function and having an imaging device,
a first step of irradiating the surveying target with light from the surveying instrument, receiving the light reflected from the first reflecting section, and collimating the surveying instrument to the surveying target by an automatic collimation function;
The light acquired in the first measurement step is acquired by the imaging device, the position of the second reflecting portion is specified by image diagnosis, and the surveying instrument is directed to the second reflecting portion of the survey target by an automatic collimation function. a second step of collimating;
A surveying method, wherein the surveying is performed based on the light reflected from the second reflecting portion by collimation in the second step. A surveying method in which the target for surveying according to any one of claims 1 to 4 is attached to an object to be surveyed, and surveying is performed using a surveying instrument having an automatic collimation function,
a first step of irradiating the surveying target with light from the surveying instrument, receiving the light reflected from the first reflecting section, and collimating the surveying instrument with the surveying target by an automatic collimation function;
The light obtained in the first measurement step is the reflected light reflected from the first reflecting unit and the second reflecting unit, and the amount of reflected light from the first reflecting unit and the second reflecting unit is calculated from the reflected light. a second step of identifying the position of the second reflecting part by measuring the difference and collimating the surveying instrument to the second reflecting part by an automatic collimation function;
A surveying method, wherein the surveying is performed based on the light reflected from the second reflecting portion by collimation in the second step.

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