JPH10227634A - Vertical collimator and method for measuring fall of tower using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To collimate the light source of a tower top part from an oblique, lower ground surface by detachably providing an inclination prism for inclination collimation on the upper part of a collimator body. SOLUTION: An inclination prism 15 for inclination collimation is detachably provided at the upper part of a collimator body 2 to constitute a vertical collimator 16. The inclination prism 15 has, for example, an inclination angle α of 1.5 deg. and refracts incidence light with an incidence angle of 1.5 deg. vertically. Further, the inclination prism 15 can be positioned accurately for a collimator body 2 by a micrometer 17 for fine adjustment of rotation and move. Then, the vertical collimator 16 accurately can measure the fall of a tower 8 with a sufficient accuracy by collimating a light source 18 being mounted a tower top part without being extended from the tower 8 from a ground surface 12 at an oblique, lower part, thus eliminating the need for providing a collimation hole at a bridge beam as before and hence preventing the problem of a measurement error from occurring due to deformation and vibration caused by the extension of a tool from the tower top.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vertical collimator for measuring the fall of a tower having a high height such as a main tower of a cable-stayed bridge / suspension bridge or other tower-like structures. The present invention relates to a method for measuring the tilt of a tower using a vertical collimator.

[0002]

2. Description of the Related Art Conventionally, the verticality of a tower such as a main tower of a cable-stayed bridge or a suspension bridge has been measured using a transit. This method uses a scale attached to the top of the tower and the base of the tower (ground surface).
The verticality is determined by collimating the tower center point (base point) inscribed with a transit installed near the tower base. In general, in the measurement by transit, since there are mechanical errors such as a horizontal axis error and a collimation axis error, errors are eliminated by averaging the values observed in positive and negative directions.

However, the collimation axis error caused by the inclination of the vertical axis of the transit itself cannot be eliminated by inversion. From this, it can be said that the method of measuring the verticality of the tower by transit has a problem in principle when the depression angle is large. Further, when the tower constantly moves slightly due to the wind, the scale does not stand still, so that there is a problem that a personal reading error increases.

[0004] As another method of measuring the inclination of the tower, for example, a method using a down swing can be considered, but there is a problem that it becomes difficult to stop the down swing when the height of the tower is high. There is also a method using a laser beam, but this method has a problem in the accuracy of the irradiation angle.

To solve such a problem, FIG.
A vertical collimator has been proposed as shown in FIG. The vertical collimator 1 is provided with a right-angle prism 3 suspended from a telescope provided vertically in a collimator body 2, and furthermore, the vertical prism 3 reflects light vertically downward and vertically upward. A camera 4 such as a CCD camera for taking an image is provided in the lateral direction, and a level using a cylindrical bubble tube (not shown) for adjusting the level of the vertical collimator 1 is provided.

[0006] The vertical collimator 1 is connected to an image processing device 5 for processing a photographed image from the camera 4 and a computer 6 such as a personal computer for measuring the inclination of the tower.

[0007] Since the right-angle prism 3 provided in the vertical collimator 1 is always in the direction of gravity, the problem of the error of the collimation axis 7 of the vertical collimator 1 is solved. Furthermore, horizontal axis error
Since the collimation error can be eliminated by inverting the telescope, the measurement error is only related to the resolution of the telescope. In addition, since the tower is measured from the time averaged value by the computer 6, the problem of tower vibration can be solved.

The procedure for measuring the tower tilt by the vertical collimator 1 will be described with reference to FIGS. 11, 12 and 13. FIG.

A light source 11 is attached to the top of a tower 8 such as a main tower of a bridge 13 via a jig 9 or 10 and a vertical line passing through the light source 11, that is, The base point 11 'of the intersection of the reference line 7' and the ground surface 12 is dropped on the ground surface 12, and the bridge axis direction X and the bridge axis perpendicular direction Y passing through the base point 11 '
A cross line (see FIG. 14) is marked on the ground surface 12. The base point 11 'can be obtained from a design drawing.

When the vertical collimator 1 is adjusted to be horizontal while looking at the level (not shown) of the vertical collimator 1, the collimating axis 7 of the vertical collimator 1 automatically becomes vertical, and It becomes parallel to the collimation line 7 '. The telescope is capable of focusing from the front of the object to infinity. A specially processed crosshair is engraved in the center of the telescope, and the crosshair visible from the camera 4 serves as a reference point for vertical measurement.

The crosshair of the telescope of the vertical collimator 1 is made to coincide with the crosshair of the base point 11 ′ on the ground surface 12 by using a centering device provided in the vertical collimator 1.

In this state, when the light source 11 at the top of the tower is collimated by the vertical collimator 1, the light source 11 is turned on when the tower is down.
Moves to a position like point P, for example, as shown on the monitor screen of FIG. On the screen processed by the image processing device 5, the point P is located at a position deviated from the base point 11 ',
This deviation corresponds to the displacement of the top. Therefore, by calculating this deviation on the screen by the computer 6, the tower 8
Can be measured. Further, by calculating the average value of the data sampled for a certain period of time by the image processing device 5, even if the tower 8 is vibrating, the center point of the vibration can be measured, so that the influence of the vibration can be removed. .

[0013]

However, when measuring the fall of the tower 8 such as the main tower of the bridge 13 using the vertical collimator 1 as described above, it is necessary to install the light source 11 on the top of the tower. It is necessary to attach the jig 9 or 10 in FIG. 11, but when attaching the jig 9 in the bridge axis direction as shown in FIG. 11, a collimation hole 14 is formed in the bridge 13 to secure the collimation line 7 ′. On the contrary, when the jig 10 is mounted so as to project in the direction perpendicular to the bridge axis as shown in FIG. 12, there is no problem if the tower 8 is vertical, but the tower 8 is shown in FIG. When the jig 10 is inclined as described above, the jig 10 is provided so as to protrude long in the lateral direction.
There is a problem that the measurement accuracy is affected by the deformation, vibration, etc.

The present invention has been made to solve the above-mentioned conventional problems, and uses a vertical collimator that enables a light source provided at the top of a tower to be collimated obliquely from below. The purpose of this study is to provide a method for measuring the fall of a tower.

[0015]

According to the first aspect of the present invention, a right angle prism is suspended in a collimator body, and a camera provided in a horizontal direction can collimate vertically upward and vertically downward. A vertical collimator according to the present invention, wherein the collimator body is provided with a tilt collimating tilt prism detachably on an upper part of the collimator body.

According to a second aspect of the present invention, a light source is provided at the top of the tower, and when the vertical collimator according to the first aspect is installed on the ground surface, an inclined collimating line connecting the inclined prism and the light source. Is scribed in advance at a position extending vertically from the inclined prism to the ground surface by a cross line, the vertical collimator is installed on the base point, and the cross line of the collimator body and the cross line of the base point are aligned. Aligning, and after aligning the crosshairs of the collimator body and the crosshairs of the inclined prism, a method of measuring the tilt of the tower, comprising collimating the camera with the light source,
It is related to.

According to a third aspect of the present invention, there is provided the method for measuring the tilt of a tower according to the second aspect, wherein the calibration is performed by providing a plurality of light sources in the tilt measuring direction. It is.

According to the first and second aspects of the present invention, the vertical collimator is provided with a tiltable collimating tilting prism detachably mounted on the upper portion of the collimator body, and is mounted on the tower top without protruding from the tower. The light source can be collimated from the ground surface diagonally below, so that the conventional collimating hole in the bridge or the prolonged extension of the jig causes a measurement error due to deformation or vibration. Can be prevented.

According to the third aspect of the present invention, the vertical collimator can be calibrated by providing a plurality of light sources in the tilt measurement direction.

[0020]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 2 shows an example of an embodiment of an apparatus for carrying out the present invention. A vertical collimating prism 15 for detachable collimating is provided on the upper part of the collimator body 2 similar to FIG. The collimator 16 is constituted. The tilt prism 15
For example, it has an inclination angle α of 1.5 °, and refracts light incident at an incident angle of 1.5 ° vertically downward. Further, the tilt prism 15 can be accurately positioned with respect to the collimator body 2 by a micrometer 17 for finely adjusting the rotation and movement.

Next, the procedure of measuring the tower tilt using the vertical collimator 16 will be described.

As shown in FIGS. 1 to 3, a light source 18 is attached to the top of a tower 8 such as a main tower of a bridge 13 via a jig 9 or 10. At this time, three light sources 18, 18 a and 18 b are provided at intervals of 100 mm and 200 mm in the direction for measuring the inclination of the tower 8, that is, in FIG. 3, in the bridge axis direction X.

Next, a vertical collimator 16 provided with the inclined prism 15 is set on the ground surface 12. At this time, when the vertical collimator 16 is installed on the ground surface 12, the position where the inclined collimation line 7 ′ connecting the inclined prism 15 and the light source 18 extends from the inclined prism 15 to the ground surface 12 is determined. A base point 18 'is provided at this position, which is obtained in advance from the drawing, and a cross line passing through the base point 18' is marked. This base point 1
The vertical collimator 16 is installed so as to be located above 8 '.

The level of the collimator body 2 is raised while looking at a level (not shown) of the collimator body 2. At this time, the collimator body 2
Make sure that the bubble of the spirit level is always at the center of the circular mark with orienting. Further, the tilt prism 15 is adjusted to be horizontal by a level (not shown) on the upper surface of the collimator body 2.

Subsequently, the cross line (XY axis) of the camera 4 is adjusted to the cross line (XY axis) of the base point 18 'while watching the monitor screen of the image processing device 5 similar to that shown in FIG. However, a shift device (not shown) is used so that there is almost no deviation between the right and the reverse of the camera 4. At this time, the level of the collimator body 2 is checked again.

Next, the collimator body 2 is positioned at the crosshair at the base point 18 '.
The rotation direction is adjusted so that the crosshairs of the (telescope) overlap in a positive state, and the rotation is clamped in the overlapped state.

The collimating direction is switched to the upper side, the camera 4 is focused on the tilt prism 15, and the cross line of the tilt prism 15 and the cross line of the collimator body 2 overlap in a normal / reverse state while watching the monitor screen. As described above, the tilting prism 15 is rotated and moved by the micrometer 17 to perform positioning. In particular, since the alignment error in the direction Y perpendicular to the bridge axis sensitively affects the measurement result, the Y-axis of the crosshair of the collimator body 2 has a gap equal to the width of the double line of the Y-axis cut by the inclined prism 15. Adjust the rotation to enter. X of tilt prism 15
Even if the axis does not coincide with the X-axis of the collimator body 2, it does not affect the measurement result, but it should be coincident as much as possible. The state in which the cross line in the positive attitude of the collimator body 2 and the cross line of the inclined prism 15 are overlapped (especially in the Y-axis direction) is clamped.

Next, the camera 4 is focused on the upper light source 18.
Collimate according to. At this time, if the tower 8 is tilted,
The light source 18 moves to the position of the point P as shown on the monitor screen of FIG. At this time, the three light sources 18, 18a, 1
Confirm that 8b is on the X-axis. If they do not match, the collimator body 2 is adjusted so as to ride on the X axis.

In the above description, the light sources 18, 18a,
It is assumed that the line connecting 18b coincides with the X-axis of the crosshair at the base point 18 'as shown in FIG. This can be checked in the manner described above.

The calculation of the inclination of the tower 8 is obtained by averaging positive and negative. As an example of calculation, forward rotation = 100 dots, reverse rotation = -108do
t, calibration value = 300mm / 130dot, measured value = (10
0 + 108) / 2 x (300/130) = 240.0 mm. That is, it is necessary to change the sign of the value at the time of inversion and average it. In addition,
The sign differs between forward rotation and reverse rotation, and the values are almost the same. When the absolute values are significantly different, it is necessary to consider that the adjustment is not perfect or that the adjustment of the vertical collimator 16 is broken.

For calibration, the target was 100 mm and 2 mm
Since the three light sources 18, 18a and 18b are provided at intervals of 00 mm, calibration can be performed using these. However, since the vertical collimator 16 can measure only in the X direction (bridge axis direction), the X axis and the light sources 18, 18a, 18
The calibration value must be obtained in a state where the lines connecting b are parallel.

In the above-described tilt measurement, when the tilt prism 15 is inverted with the tilt prism 15 mounted on the collimator body 2, the light source 1
Since 8, 18a and 18b are out of the field of view, only the collimator body 2 is inverted with the inclined prism 15 raised,
The tilt prism 15 must be installed again in the direction before the inversion. At this time, an “alignment error” for aligning the cross line of the inclined prism 15 with the cross line of the collimator body 2 occurs. Since this error has a direct effect on the measurement accuracy, this was examined.

When the vertical collimator 16 is installed, the cross line of the collimator body 2 is aligned with the cross line of the base point 18 'on the ground surface, and then the cross line of the inclined prism 15 and the collimator body 2 are aligned.
The causes of the alignment error generated during the operation of aligning the crosshairs of the collimator and the tilt prism 1 are as follows.
5 alignment error, base point 1 on ground surface 12
Alignment error between the crosshair 8 ′ and the crosshair of the collimator body 2,
A deviation angle error at the time of manufacturing the inclined prism 15 and the like can be considered.

As shown in FIG. 5, the cause of the error is an alignment error when the center line of the cross line of the inclined prism 15 is within 1/2 of the cross line thickness of the collimator body 2. Think of it as an error.

If the length of the cross line of the collimator body 2 is 4 mm and the width (thickness) of the cross line is 3 μm, the deviation angle error at this time is tan ^−1.
(1.5 × 10 ^−3/4 ) = 77 ″.

The error of irrespective of the alignment error of the inclined prism 15, the light source 18 and the base point 1 on the ground surface 12 have no relation.
8 'and a deviation error with respect to the X axis. Since this deviation error is very small, it can be ignored. The geometric error can be reduced to 3 mm or less even if it is largely estimated. Also, consider a deviation error of 60 ″ as a deviation angle at the time of manufacture.
Consider 60 = 137 ″.

Influence of Declination Error on Measurement Accuracy Considering a coordinate system as shown in FIG. 6, it is assumed that the inclined prism 15 is placed as shown in FIG. Refraction appears only in the XZ plane. At this time, the deviation error: β = 0.
When the tilt prism 15 is rotated around the Z axis by an angle β (clockwise is positive), the direction cosine is (l,
m, n), assuming that the inclination angle of the inclined prism 15 is α, l
= −sinα cosβ, m = −sinα sinβ, n = cosβ.

Let dv be the measurement error of the tilt of the tower 8 when the tilt prism 15 has a deviation error β. In FIG. 8, assuming that the height up to the collimation position (light source 18) is H and the inclination angle of the collimation line 7 ′ is α, L = H / cos α and dv = L × m. (H / cos α) sin α sin β.

From this, the measurement error dv of the tilt error of the tower 8 is calculated.
Is proportional to the height of the tower 8 and the value increases as the inclination angle α increases. As an example, a tower 8 of H = 220 m
Was measured. At this time, the inclination angle α of the inclination prism 15 was set to 1.5 ° in consideration of the installation state of the erection scaffold and the like.

FIG. 9 shows a calculation result of the measurement error dv with respect to the deviation error β. FIG. 9 shows that the deviation error β and the measurement error dv are in a proportional relationship.

Measurement error of the vertical collimator 16 The above is the alignment error of the inclined prism 15, but the influence of the error due to the resolution of the telescope and the camera 4 must be considered.

When the resolution of the telescope incorporated in the vertical collimator 16 is 3 ″, the resolution when the height of the tower 8 is 220 m is 3.2 mm.

When the focal length of the camera lens is 25 mm, the field of view of the camera 4 at a distance of 220 m is vertical: 5
87mm, width: 806mm. Camera 4 by CCD camera
Has a resolution of 350 pixels vertically and 380 pixels horizontally.
The resolution per pixel is 1.7 mm vertically and 2.1 mm horizontally.

Assuming that each error is independent, the sum of the errors can be evaluated by the root mean square. If the deviation angle error is about 137 ″, it is considered possible to reduce the measurement error of the entire system to 10 mm or less.

Here, when the allowable fall error in the actual construction of the main tower of the bridge was investigated, the allowable fall error was approximately 1/2000 of the height of the main tower. When the height of the main tower is 220 m, the allowable tilt error is 110 mm. If the measurement error is within 10 mm as described above, this value is approximately 1/10 of the allowable tilt error.
Which is a reasonable value.

Therefore, as described above, the tilt prism 15
According to the vertical collimator 16 provided with the collimator, the light source 18 mounted on the top of the tower without projecting from the tower 8 is collimated from the ground surface 12 obliquely below, so that the tower 8 can be tilted with sufficient accuracy. Since the measurement can be performed, the problem of opening the collimation hole 14 in the bridge 13 as shown in FIG. 11 can be prevented, or the jig 10 can be extended and deformed or vibrated as shown in FIG. Thus, it is possible to prevent the occurrence of a problem that a measurement error occurs.

[0048]

According to the first and second aspects of the present invention,
At the top of the collimator body, a vertical collimator equipped with a detachable inclined collimation prism for collimating collimation collimates the light source attached to the top of the tower without protruding from the tower from the ground surface obliquely below. Therefore, it is possible to prevent a problem that a measurement error is caused by deformation or vibration by forming a collimating hole in a bridge or extending a jig as in the related art.

According to the third aspect of the present invention, the light source is
Calibration of the vertical collimator can be performed by providing a plurality of tilt collimators in the tilt measurement direction.

[Brief description of the drawings]

FIG. 1 is a front view of a tower showing an example of an embodiment of the present invention.

FIG. 2 is a schematic diagram specifically showing the apparatus of FIG. 1;

FIG. 3 is a view taken in the direction of arrows III-III in FIG. 2;

FIG. 4 is a schematic diagram of a monitor screen at the time of measurement according to the present invention.

FIG. 5 is a schematic diagram showing an alignment error between a cross line of a collimator body and a cross line of an inclined prism.

FIG. 6 is a chart for explaining deviation angle errors.

FIG. 7 is an installation chart of a tilt prism.

FIG. 8 is a chart for explaining a measurement error due to a deviation error.

FIG. 9 is a diagram illustrating a relationship between a declination error and a measurement error.

FIG. 10 is a system diagram of a conventional vertical collimator and its measuring device.

FIG. 11 is a front view of a tower to which the device of FIG. 10 is applied.

FIG. 12 is a side view of a tower to which the apparatus of FIG. 10 is applied.

FIG. 13 is a schematic diagram specifically showing the apparatus of FIG. 10;

FIG. 14 is a schematic diagram of a monitor screen at the time of measurement by the device of FIG. 10;

[Explanation of symbols]

 2 collimator body 3 right angle prism 4 camera 15 tilt prism 16 vertical collimator 18, 18a, 18b light source 18 'base point

Claims (3)

[Claims] 1. A vertical collimator in which a right-angle prism is suspended in a collimator main body so that a camera provided in a horizontal direction can collimate vertically upward and vertically downward. A vertical collimator comprising a collimator body and a tilt prism for tilt collimation detachably provided on an upper part of the collimator body. 2. A light source is provided at the top of the tower, and when the vertical collimator according to claim 1 is installed on the ground surface, an inclined collimation line connecting the inclined prism and the light source is vertically grounded from the inclined prism. A base point with a cross line is scribed in advance at a position extending to the surface, the vertical collimator is installed on the base point, the cross line of the collimator body and the cross line of the base point are aligned, and collimation is performed. A method for measuring the inclination of a tower, comprising: aligning a cross line of a vessel main body with a cross line of an inclined prism, and then collimating a camera by focusing on the light source. 3. The tower tilt measuring method according to claim 2, wherein a plurality of light sources are provided in the tilt measuring direction to perform the calibration.