JP2006258760A - Displacement measuring system and displacement measuring method for long object - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a displacement measuring system for a long object, capable of precisely measuring the displacement in the vertical direction, even when the length of the long object in the longitudinal direction is markedly different from the dimension of the displacement width in the vertical direction. <P>SOLUTION: In the displacement measuring system 10, positional information of the long object 1 to be measured is collected by using a polygon mirror 12, consisting of a polyhedron having a face parallel to a direction perpendicular to the longitudinal direction. The image of a plurality of discontinuous parts of the long object is photographed by a camera 14 via each face thereof, and the position of the long object in the vertical direction is detected from the image by a computer 16. Accordingly, representative parts of the long object in the longitudinal direction are extracted and joined together so that an image permitting grasp of the entire long object is photographed, and the position in the vertical direction is detected. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a long object displacement measurement system and a displacement measurement method.

  Long structures such as bridges may bend in the vertical direction (that is, the direction perpendicular to the longitudinal direction) due to their own weight, strong wind, etc., so it is necessary to measure this vertical displacement for safety reasons. There is. As a conventional system for measuring the displacement in a direction perpendicular to the longitudinal direction of such a long object, there is a technique described in Patent Document 1, for example. According to this document, a three-dimensional laser scanner is used to acquire bridge displacement as image data.

JP 2004-325209 A

  However, when the length of the long object in the longitudinal direction and the scale of the displacement width in the vertical direction are significantly different, it is difficult to accurately measure the displacement in the vertical direction. Taking a bridge as an example, while the length in the longitudinal direction is several hundred meters to several kilometers, the displacement width in the vertical direction is about several millimeters, so the image in the longitudinal and vertical directions is the same scale. If you want to take a picture, if you use the longitudinal direction as a reference, the vertical displacement is too small to measure almost, and if you use the vertical direction as a reference, you must shoot an extremely long image that is practically impossible. did not become.

  Accordingly, the present invention provides a displacement measurement of a long object that can accurately measure the displacement in the vertical direction even when the length of the long object is significantly different from the scale of the displacement width in the vertical direction. It is an object to provide a system and a displacement measuring method.

A displacement measuring system for a long object according to the present invention is a system for measuring a displacement of a long object in a longitudinal direction and a vertical direction, and a condensing means comprising a polyhedron having a plane parallel to the vertical direction; Imaging means for taking images of a plurality of discontinuous parts of the long object through each surface of the light collecting means, and detection means for detecting the vertical position of the long object from the image. It is characterized by providing.

  The long object displacement measuring method according to the present invention is a method for measuring the displacement of a long object in the longitudinal direction and the vertical direction, and is a light collecting device comprising a polyhedron having a plane parallel to the vertical direction. A condensing step of condensing using the means, an imaging step of taking images of a plurality of discontinuous parts of the long object through each surface of the condensing means, and the long object from the image And a detection step of detecting a position in the vertical direction.

  In the long object displacement measurement system, it is also preferable that the light condensing means is rotatable about the vertical direction as a central axis.

  In the above-described long object displacement measuring method, it is also preferable that in the light collecting step, light can be collected by rotating the light collecting means about the vertical direction as a central axis.

  In the long object displacement measurement system, it is also preferable that the light condensing means is rotatable at a constant speed with the vertical direction as a central axis.

  In the above-described long object displacement measuring method, it is also preferable that in the light collecting step, light can be collected by rotating the light collecting means at a constant speed with the vertical direction as a central axis.

  In the long object displacement measurement system, it is also preferable that the light condensing means can rotate in a forward and reverse direction within a predetermined angle range with the vertical direction as a central axis.

  In the long object displacement measuring method, in the light collecting step, the light collecting means may be able to collect light by rotating the light condensing means in a predetermined angular range in the forward and reverse directions with the vertical direction as a central axis. preferable.

  In the long object displacement measurement system, it is also preferable that the detection means detects the position of the long object in the vertical direction in time series.

  In the long object displacement measuring method, it is also preferable that the detection step detects the position of the long object in the vertical direction in time series.

  In the long object displacement measurement system in which the detection unit performs time-series detection, the detection unit determines the vertical position of the long object based on a position at a past time. It is also preferable to detect by searching within a certain range.

  Further, in the displacement measuring method for a long object that performs time-series detection in the detection step, the vertical position of the long object is determined based on a position at a past time in the detection step. It is also preferable to detect by searching within a certain range.

  In the long object displacement measurement system, it is also preferable to further include an irradiating unit that irradiates a plurality of discontinuous portions of the long object through the light collecting unit.

  The long object displacement measuring method preferably further includes an irradiation step of irradiating a plurality of discontinuous portions of the long object through the light collecting means.

According to the long object displacement measurement system and displacement measurement method according to the present invention, the position information of the long object to be measured is collected using a polyhedron having a plane parallel to the direction perpendicular to the longitudinal direction. The light is collected, and images of a plurality of discontinuous portions of the long object are photographed through the respective surfaces, and the vertical position of the long object is detected from the image. That is, representative portions in the longitudinal direction of the long object are extracted, and an image that can grasp the entire long object is captured and the position in the vertical direction is detected. Therefore, even when it is desired to take an image with the longitudinal direction and the vertical direction being the same scale, it is possible to accurately measure the vertical displacement of the long object.

  In addition, by making the condensing means rotatable about the vertical direction of the long object as a central axis, the representative part in the longitudinal direction to be photographed can be easily changed, and the measurement accuracy can be further improved. . Furthermore, if the condensing means is rotated at a constant speed, a wide range in the longitudinal direction can be measured as a representative part, and if the condensing means is rotated in the forward and reverse directions within a predetermined angle range, the longitudinal direction can be measured. Only the necessary range can be accurately measured as a representative part, and each is suitable.

  In addition, by detecting the vertical position of the long object in time series, it is possible to measure the dynamic displacement of the long object in the vertical direction, and to diversify the displacement measurement. .

  In addition, when performing time-series detection, the vertical position of the long object is searched within a certain range determined based on the position at the past time (for example, the fluctuation expected from the position at the previous time) If it is detected by searching within the range), the vertical position search of the long object can be performed easily and quickly, and the dynamic displacement can be measured more efficiently. .

  In addition, if a plurality of discontinuous parts (that is, parts to be imaged) of a long object are irradiated through the light collecting means, measurement is possible even at night or in cloudy weather. At this time, by irradiating the site to be imaged through the light collecting means, less energy is required than when irradiating the entire long object.

  First, the configuration of the long object displacement measurement system according to the present embodiment will be described with reference to FIG. This displacement measurement system 10 is a system that measures displacement in a direction (y-axis direction in the figure) perpendicular to the longitudinal direction (x-axis direction in the figure) of the bridge 1 to be measured, and a polyhedral mirror 12 (condensing means). ), A camera 14 (imaging means), a computer 16 (detection means), and a light source 20 (irradiation means). Hereinafter, each component will be described in detail.

The polyhedral mirror 12 includes a plurality of plate-like half mirrors (semi-transmissive mirrors) 12a, 12b,... Which are the same number as the representative measurement site of the bridge 1 (x ₁ x ₂ x ₃ x ₄ . Each surface is parallel to the axis and faces the bridge 1 side, and has a structure in which each surface is joined in a concave shape so as to reflect an image of each part with respect to the camera 14 as x ₁ x ₂ x ₃ x ₄ . Light sources 20a, 20b,... Are provided on the back surfaces of the plate-shaped half mirrors 12a, 12b,..., And each representative measurement site of the bridge 1 is irradiated through the plate-shaped half mirrors 12a, 12b,. It is possible. Further, the polyhedral mirror 12 and the light sources 20a, 20b,... Are arranged on the turntable 18, and by operating the turntable 18 manually or automatically, the polyhedral mirror 12 and the light sources 20a, 20b,. Alternatively, it can be rotated in the forward and reverse directions within a predetermined angle range.

The camera 14 is a camera that can digitally shoot still images and moving images, and is arranged at a position where x ₁ x ₂ x ₃ x ₄ reflected on each mirror surface of the polyhedral mirror 12 can be captured in the same image. Has been. In addition, the camera 14 has a performance capable of identifying at least the number of pixels in the y-axis direction equal to or more than the number of representative measurement portions x ₁ x ₂ x ₃ x ₄ . It is preferable to have a high pixel and a high frame rate according to the required accuracy.

The computer 16 is connected to the camera 14 via a cable, and can capture an image photographed by the camera 14 and save it in a built-in memory. The computer 16 also performs image processing for searching for a boundary line between the bridge 1 and the background in the image sent from the camera 14 and a search determined based on a position at a past time during the processing. Software necessary for arithmetic processing for calculating the power range is installed.

Next, the operation of the long object displacement measurement system according to the present embodiment (the long object displacement measurement method according to the present embodiment) will be described. First, when measurement is performed at night or in cloudy weather, the light sources 20a, 20b... Are turned on in advance to irradiate the representative measurement sites x ₁ x ₂ x ₃ x ₄ . First, the image of the representative measurement site x ₁ x ₂ x ₃ x ₄ ... Of the bridge 1 at time t ₁ is reflected on each surface of the polyhedral mirror 12 (that is, the image of the site x ₁ is reflected on the mirror surface 12a and the site x. ₂ images are reflected on the mirror surface 12b, respectively), and taken by the camera 14 in the same image. An image photographed by the camera 14 is taken into the computer 16 and stored in a built-in memory.

The computer 16 detects the boundary position between the bridge 1 and the background of each part x ₁ x ₂ x ₃ x ₄ ... From the captured image. More specifically, a horizontal axis pixel corresponding to the part x ₁ is searched, and the boundary pixel between the bridge 1 and the background is searched by scanning the pixel in the vertical axis direction. The same processing is performed for the parts x ₂ x ₃ x ₄ ..., And the boundary pixels of each part are searched and detected as the boundary position. The boundary positions of the detected parts x ₁ x ₂ x ₃ x ₄ ... Are set as y ₁ y ₂ y ₃ y ₄ ..., And a displacement measurement result in a two-dimensional coordinate format as shown in FIG.

After the measurement at the time t ₁ has been performed, the measurement at time t ₂ is performed. The operation is the same as that at time t ₁ until the image is captured by the computer 16, but when the boundary position between the bridge 1 and the background of each part x ₁ x ₂ x ₃ x ₄ ... Is detected at time t ₁ . Measurement results are used. More specifically, when the boundary pixel between the bridge 1 and the background of the part x ₁ is scanned in the vertical axis direction, the fluctuation expected from the position y _{1 at the} immediately preceding time t ₁ in order to improve the efficiency and speed of the search. Only the range α (within the dotted line in the example of FIG. 2) is searched. Such an operation is repeated after time t ₃ t ₄ ... And dynamic displacement is measured.

  When the representative measurement site is to be changed, the measurement operation may be performed after the turntable 18 is rotated by a predetermined angle after a series of measurement operations are completed. In particular, when it is desired to measure a wide range in the longitudinal direction as a representative part, the turntable 18 is rotated at a constant speed, and when only a necessary range in the longitudinal direction is desired to be measured as a representative part, the turntable 18 is set to a predetermined angular range. Rotate inside in forward and reverse directions. As a result, mutations can be measured for many sites, so that the overall measurement accuracy is further improved.

  The long object displacement measurement system and the displacement measurement method according to the present invention are not limited to the above-described embodiments, and various modifications can be adopted. For example, in the above-described embodiment, an example in which a reflective polyhedral mirror is used as the light collecting unit has been described. However, a transmission type polyhedral lens may be used as the light collecting unit.

  In the above-described embodiment, an example in which a single polyhedral mirror is used as the light collecting unit and a single camera is used as the imaging unit has been described. However, a plurality of polyhedral mirrors or a plurality of cameras are used, or a polyhedral mirror and a camera are used. It is good also as measuring by combining two or more. As a result, the number of representative measurement sites in the longitudinal direction, which are imaging targets, can be increased to further increase the accuracy.

1 is a configuration diagram of a long object displacement measurement system according to the present embodiment. FIG. It is a chart which shows an example of a measurement result.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Bridge, 10 ... Displacement measuring system, 12 ... Polyhedral mirror, 14 ... Camera, 16 ... Computer, 18 ... Turntable, 20 ... Light source

Claims (14)

A system for measuring the displacement of a long object in the longitudinal direction and the vertical direction,
A light collecting means comprising a polyhedron having a plane parallel to the vertical direction;
Imaging means for taking images of a plurality of discontinuous portions of the elongated object through each surface of the light collecting means;
And a detection means for detecting the vertical position of the long object from the image. 2. The long object displacement measuring system according to claim 1, wherein the condensing means is rotatable about the vertical direction as a central axis. 3. The long object displacement measuring system according to claim 2, wherein the light collecting means is rotatable at a constant speed with the vertical direction as a central axis. 3. The long object displacement measuring system according to claim 2, wherein the condensing means is rotatable in a forward and reverse direction within a predetermined angle range with the vertical direction as a central axis. 5. The long object displacement measurement system according to claim 1, wherein the detection unit detects the position of the long object in the vertical direction in time series. 6. The long length according to claim 5, wherein the detection means detects the vertical position of the long object by searching within a certain range determined based on a position at a past time. Displacement measurement system. The long object displacement measurement system according to claim 1, further comprising an irradiation unit configured to irradiate a plurality of discontinuous portions of the long object through the light collecting unit. A method of measuring the displacement of a long object in the longitudinal direction and the vertical direction,
A condensing step of condensing using condensing means comprising a polyhedron having a plane parallel to the vertical direction;
An imaging step of capturing images of a plurality of discontinuous portions of the elongated object through each surface of the light collecting means;
A detection step of detecting the position of the long object in the vertical direction from the image. 9. The long object displacement measuring method according to claim 8, wherein in the condensing step, the condensing means can be condensed by rotating the condensing means about the vertical direction as a central axis. The long object displacement measuring method according to claim 9, wherein in the condensing step, the condensing unit can condense by rotating the condensing unit at a constant speed with the vertical direction as a central axis. 10. The long object according to claim 9, wherein in the condensing step, the condensing unit can condense by rotating the condensing unit in a forward and reverse direction within a predetermined angle range with the vertical direction as a central axis. Displacement measurement method. The long object displacement measuring method according to any one of claims 8 to 11, wherein, in the detection step, the vertical position of the long object is detected in time series. The long length according to claim 12, wherein in the detection step, the vertical position of the long object is detected by searching within a certain range determined based on a position at a past time. Displacement measurement method. The long object displacement measuring method according to any one of claims 8 to 13, further comprising an irradiation step of irradiating a plurality of discontinuous parts of the long object through the light collecting means.

Images