JP2012173027A - Self-light-emitting type target and displacement measuring system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a self-light-emitting type target for displacement measurement in which displacement can be measured outdoors continuously night and day and a measurement error is reduced, and a displacement measuring system with the same.SOLUTION: A self-light-emitting type target for displacement measurement (target 2 for measurement) is used for a displacement measuring system 1 which performs a displacement measurement on a measurement object (a rail) by analyzing an image captured by imaging means (a camera 3) through analysis means (a PC 4), and emits light by itself while being mounted on the measurement object (the rail). The target 2 for measurement is an inner illumination self-light-emitting type target including a case 20, light-emitting means 21 which emits light while being mounted in an internal portion at a back side of the case 20, and a phosphorescent plane member 22 which is mounted in an internal portion at a front side of the case 20, contains a phosphorescent phosphor and a light transmissible substance and is molded in a plate shape.

Description

  The present invention relates to a self-luminous target used for displacement measurement by imaging, and a displacement measuring system including the self-luminous target.

  In construction such as civil engineering and construction, there is a possibility of affecting the structure adjacent to the construction area, and for the sake of safety, the displacement of the adjacent structure is measured. For example, in the case of construction that builds an underpass under the track, if the track sinks due to the work or if the track is distorted, it may lead to a major disaster. There is a strong demand that the displacement of the orbit must be monitored for 24 hours for the purpose of coping.

  As a technique for measuring the displacement of a structure outdoors, conventionally, a target made of reflective tape or a target made of a square of any one of red, green, and blue as a target for measurement on a displacement measurement object, etc. A reflective target is installed, and the target is continuously and periodically imaged with imaging means such as a CCD camera or digital camera (including both still image shooting with a camera and movie shooting with a movie, the same applies hereinafter). The image is stored in the storage device, and the electronic image data photoelectrically converted by each image element of the camera stored in the storage device is analyzed by a computer, so that the displacement of the target can be detected from fluctuations in image brightness and RGB level distribution. Displacement measurement systems using a reflective target that detects the displacement of a measurement object by detecting an object (for example, Patent Documents 1 and 2).

  However, the rail displacement measurement / alarm system and the relative displacement amount measurement system described in Patent Literature 1 and Patent Literature 2 sense light reflected by the target with each image element of the imaging means, and the relative luminance with respect to the surroundings. Since the centroid position on the target image is determined from the difference (contrast) of the RGB level and the target position is specified, if multiple targets do not have uniform illuminance, the image data is analyzed by a computer The contour of the target to be detected is unclear, the centroid position calculated from the target is inaccurate, and there is a problem that the measurement accuracy is lowered or an error occurs. In addition, when the amount of solar radiation decreases at night or in rainy weather, the light emitting device emits light to irradiate the target. To achieve uniform illumination for multiple targets, multiple light sources such as lighting are used. The device must be installed so that it can irradiate the target from various angles, which increases the installation cost and, depending on the situation in the field, there are many cases where a large number of light emitting devices cannot be installed in multiple directions. .

  A displacement measurement system using a self-luminous target in which the target itself has a light emitting function in order to eliminate such an error in contour detection due to the difference in illuminance of the reflective target is also known. For example, in Patent Document 3, as a target for displacement measurement, an LED, a diffusion plate that equalizes the brightness of transmitted light of the light emitted from the LED, a press plate that limits the optical path to a circle, and a direction other than the shooting direction are disclosed. Using a target consisting of a light-shielding mask that shields light entering from the direction, a plurality of these targets are placed on the sleepers of the trajectory that is the object of displacement measurement, and these multiple targets are photographed simultaneously with a single digital camera. Orbital displacement measuring device that analyzes the captured image to determine the centroid position of the target from the luminance difference (contrast) between the target and the surroundings, and measures the displacement of the orbit compared with the initial value measured in advance Is disclosed.

  However, even with such a self-luminous target, when displacement measurement is performed continuously for 24 hours day and night in the outdoors where direct sunlight falls, (1) a longer camera exposure time is taken during night photography. And overexposure, the outline of the target part becomes blurred and the measurement accuracy decreases. (2) The shadow of the shading mask due to sunlight falls on the target circular part during daytime shooting, and the target outline is not grasped as a circle. However, there is a problem that the measurement accuracy decreases.

JP 10-325703 A JP 2001-272228 A JP 2010-25855 A

  Accordingly, the present invention solves the above-described problems of the prior art, a self-luminous target for displacement measurement capable of continuously measuring displacement outdoors during daytime and with little measurement error, and displacement measurement provided with the same. The purpose is to provide a system.

  In order to solve the above-mentioned problem, the invention according to claim 1 is used in a displacement measurement system that measures a displacement of a measurement object by analyzing an image picked up by an image pickup means with an analysis means. A self-luminous target for displacement measurement that is attached and emits light by itself, and is close to the case, the light emitting means that is attached inside the back side far from the imaging means of the case and emits light, and the imaging means of the case A phosphorescent surface material that is attached to the inside of the front surface and contains a phosphorescent phosphor and a light-transmitting substance and is molded into a plate shape, and stores the light emitted by the light emitting means with the phosphorescent surface material. And emitting fluorescence on the imaging means side.

  According to a second aspect of the present invention, in the self-luminous target according to the first aspect, the case has a circular hole formed on the imaging means side, and the phosphorescent surface material is attached to the inside of the hole. In the case, the fluorescent light is emitted in a circular shape from the phosphorescent surface material to the image pickup means side by shielding a portion other than the hole in the case.

  The invention according to claim 3 is the self-luminous target according to claim 1 or 2, wherein the light transmissive material of the phosphorescent face material is light transmissive inorganic particles, and the phosphorescent face material is The light emitted from the light emitting means can be transmitted.

  According to a fourth aspect of the present invention, in the self-luminous target according to any one of the first to third aspects, the light emitting means is an LED that emits ultraviolet light, and the phosphorescent surface material absorbs ultraviolet light. It contains a phosphorescent phosphor that emits as visible light.

  An invention of a displacement measuring system according to a fifth aspect is the self-luminous target according to any one of the first to fourth aspects, an imaging means for imaging the self-luminous target, and an image captured by the imaging means. Analyzing means for analyzing and determining the position of the self-luminous target, and measuring the displacement of the measurement object from the displacement of the self-luminous target.

  The displacement measurement system according to claim 6 is the displacement measurement system according to claim 5, wherein the displacement measurement system includes six or more fixed point targets attached to a fixed structure, and the analysis unit includes the imaging unit. Based on the measured image and the three-dimensional coordinates of the fixed point target actually measured by the surveying, the positional deviation of the imaging means is confirmed, and the measurement is performed based on the positional deviation amount obtained by calculating the positional deviation amount. The displacement of the object is corrected.

  The present invention is as described above, and according to the first aspect of the present invention, the present invention is used in a displacement measurement system that measures the displacement of a measurement object by analyzing an image captured by an image capturing unit using an analysis unit. A self-luminous target for displacement measurement that is attached to a measurement object and emits light by itself; a case; a light emitting means that is attached to the back side of the case far from the imaging means and emits light; and A phosphorescent surface material that is attached to the inside of the front surface near the image pickup means and contains a phosphorescent phosphor and a light-transmitting substance, and is molded into a plate shape, and the light stored by the light emitting means Since light is stored in the face material and fluorescent light is emitted to the imaging means side, since the fluorescent light emitted from the light storage surface material is used as a target, the brightness difference (contrast) with the surroundings of the target is large even at night imaging. No longer too, also it is possible to ensure the measurement accuracy not overexposed as the automatic control by the image pickup means exposure control. Even in daytime imaging, the target can be recognized regardless of fluctuations in the amount of sunlight and the presence or absence of shadows due to the weather. Therefore, displacement measurement can be performed continuously day and night in the outdoors, and there is little possibility of erroneously recognizing the position of the target during image analysis, and measurement errors can be reduced. Furthermore, even when bad weather such as rainy weather continues, the phosphorescent surface material can be stored only by causing the light emitting means to emit light, so that the displacement can be continuously measured regardless of the weather.

  According to a second aspect of the present invention, in the self-luminous target according to the first aspect, the case has a circular hole formed on the imaging means side, and the phosphorescent surface material is disposed inside the hole. Since the fluorescent light is emitted in a circular shape from the phosphorescent surface material to the imaging means side by shielding the part other than the hole with the case, the light emitting part of the target becomes circular in addition to the above-described effects. Therefore, regardless of the difference in the inclination and angle of the target, the luminance changes on a vertical line that bisects a line segment connecting points where the luminance changes on a certain horizontal line in the image captured by the imaging means, and on a certain vertical line. Since the intersection of the perpendicular line that bisects the line segment connecting the points becomes the centroid of the target, analysis and calculation for determining the target position from the image by the analysis means is easy and can be executed in a short time in program execution Both can be further reduced measurement error.

  According to the invention described in claim 3, in the self-luminous target according to claim 1 or 2, the light-transmitting substance of the phosphorescent face material is light-transmitting inorganic particles, and the phosphorescent face material is Since the light emitted from the light-emitting means can be transmitted, in addition to the above-described effects, the light-transmitting property is ensured by inexpensive inorganic particles, so that the cost can be reduced and the light can be stored by some accident. Even in the case where the light emission luminance of the face material is insufficient, the light emission means can be turned on to increase the light emission luminance of the target so that the luminance is appropriate.

  According to a fourth aspect of the present invention, in the self-luminous target according to any one of the first to third aspects, the light emitting means is an LED that emits ultraviolet light, and the phosphorescent face material absorbs ultraviolet light. Since it contains phosphorescent phosphors that emit as visible light, it emits light with an LED that consumes less power for the required time, in addition to the above-mentioned effects, and thus it can save the necessary power. The phosphorescent phosphor that absorbs ultraviolet rays and emits it as visible light has a longer phosphorescence time than other phosphorescent phosphors, so it can take a longer time for the phosphorescent surface material to emit light above a certain luminance. it can. Therefore, further labor saving of required power can be achieved.

  According to the fifth aspect of the present invention, the self-luminous target according to any one of the first to fourth aspects, the imaging means for imaging the self-luminous target, and the image captured by the imaging means are analyzed. And analyzing means for determining the position of the self-luminous target, and measuring the displacement of the measurement object from the displacement of the self-luminous target, so that the above-mentioned effects can be exhibited in the displacement measuring system.

  According to the displacement measurement system according to claim 6, in the displacement measurement system according to claim 5, the displacement measurement system has six or more fixed point targets attached to a fixed structure, and the analysis means includes the imaging unit. Based on the measured image and the three-dimensional coordinates of the fixed point target actually measured by the surveying, the positional deviation of the imaging means is confirmed, and the measurement is performed based on the positional deviation amount obtained by calculating the positional deviation amount. Since the displacement of the object is corrected, the displacement of the measurement object can be measured with higher accuracy in addition to the above-described effects.

1 is a configuration explanatory diagram showing a schematic configuration of a displacement measurement system according to an embodiment of the present invention. It is a vertical sectional view showing a schematic structure of a self-luminous target according to an example of the present invention. FIG. 3 is a perspective view showing a schematic configuration of the self-luminous target of FIG. 2. It is a front view of the fixed point target which concerns on an Example. (A) shows the fixed point target which concerns on Example 1, (b) shows the fixed point target which concerns on Example 2. FIG. It is a flowchart at the time of setting measurement conditions in a displacement measurement system. It is a flowchart at the time of setting camera conditions in a displacement measurement system. It is a flowchart at the time of measuring a displacement with a displacement measurement system.

  An embodiment of the present invention will be described with reference to the drawings.

  First, with respect to the displacement measurement system and the self-luminous target according to the embodiment of the present invention, the measurement object is a track (rail) using FIGS. 1 to 4 and is performed on the side surface (rail web) of the track. The case where a plurality of targets according to the example are attached and the displacement of the orbit is measured will be described.

[Displacement measurement system]
In the displacement measurement system 1 according to the embodiment of the present invention, a plurality of measurement targets 2 attached to a side surface of a track, which is a measurement object, and the measurement object are less affected by construction that does not cause the support ground to continue. A plurality of fixed point targets 2 ′ attached to a fixed structure built in a range, a camera 3 that is an imaging means for simultaneously imaging the measurement target 2 and the fixed point target 2 ′, and imaging by the camera 3 A PC (personal computer) 4 which is an analysis means for analyzing the obtained image and determining the position of the target 2 and an external hard disk 5 which is an external storage means for storing an image captured by the camera 3 are included.

(Measurement target)
First, a measurement target that is a self-luminous target according to an embodiment of the present invention will be described with reference to FIGS. 2 and 3. As shown in the figure, the measurement target 2 has a case 20, a light emitting means 21, and a phosphorescent face material 22, and the light emitted by the light emitting means 21 is accumulated by the phosphorescent face material 22 and is shown in FIG. 2. It is an internally illuminated self-luminous target that emits fluorescence (phosphorescence) in a circular shape on the means side. The measurement target 2 may not be directly attached to the rail, such as attached to a sleeper that supports the rail. In short, what is necessary is just to be directly or indirectly attached to what moves with a rail, when a support ground sinks or slips.

  The case 20 is a substantially box-shaped case having a circular opening 20a opened in a circular shape on the imaging means side which is the front side, and the light emitting means 21 is attached to the inside of the back surface (surface far from the imaging means) of the case 20. It has been.

  The light emitting means 21 is an ultraviolet ray (having a wavelength of about 10 to 400 nm which is shorter than visible light and longer than X-ray. However, from the viewpoint of efficiently emitting a phosphorescent phosphor described later, the wavelength peaks at 360 nm. It is mainly composed of a plurality of LEDs 21a arranged in an arc shape that radiates near ultraviolet rays and the base 21b, and is electrically connected to a power source (not shown). Of course, the light emitting means 21 is not limited to the LED as long as it has a light emitting function, and known light emitting means such as an organic EL (Organic Electro-Luminescence), a fluorescent lamp, and an incandescent bulb can be used. However, from the viewpoint of efficiently storing light in a phosphorescent surface material described later, the light emitting means is preferably an LED that irradiates ultraviolet rays.

  Further, a phosphorescent surface material 22 is attached to the front surface (surface near the imaging means) side of the case 20 and inside the circular opening 20a, and the case 20 shields the portion other than the circular opening 20a of the phosphorescent surface material 22 with the case 20. By doing so, the optical path of the fluorescence emitted by the phosphorescent surface material 22 is circular. The phosphorescent surface material 22 is molded into a plate shape containing a phosphorescent phosphor and a light-transmitting substance using a binder resin (matrix resin) as a base.

  As the binder resin, various light-transmitting resins such as methacrylic resin such as polymethyl methacrylate (PMMA), polycarbonate resin, acrylic resin, styrene resin, silicone resin, and polyester resin can be used.

  In addition, as a phosphorescent phosphor, any ordinary phosphorescent phosphor can be used. For example, organic fluorescent dyes such as fluorescein, rhodamine, eosin, pyramidine, naphthalimide, perylene, strontium aluminate, etc. A material obtained by adding a rare earth oxide such as heavy metal or europium as an activator to a phosphorescent material can be used. In this embodiment, there is provided a phosphorescent phosphor capable of emitting fluorescent light (phosphorescence) having a desired constant luminance or higher, which is necessary for photographing measurement described later, by absorbing ultraviolet rays and emitting light for a long time (preferably 24 hours or more). It is used.

  As the light-transmitting substance, light-transmitting inorganic particles (for example, crushed products of quartz-based natural stone, glass powder, transparent inorganic particles such as aluminum hydroxide) are preferable, and the particle diameter thereof is 180 μm to 9.5 mm. More preferably, it is composed of a fine grain component and a fine grain component under 180 μm. Of course, the inorganic particles may be chromatic as long as they are transparent colors that transmit light.

  According to the measurement target 2 which is a self-luminous target according to the embodiment as described above, it is possible to store light in the phosphorescent face material 22 at any time by appropriately lighting the LED 21a which is artificial illumination. Even when the weather is bad, the light emitted from the phosphorescent surface material 22 does not fall below a certain luminance, and the variation in the light emission amount (luminance) can be reduced. Moreover, since the phosphorescent surface material 22 is attached to the front side of the case 20, it can absorb and store ultraviolet rays in sunlight, and it can be stored in the daytime without causing the LED 21a to emit light when the weather is fine. Light can be stored and emitted at night. Therefore, the LED 21a only needs to be lit when it is necessary during cloudy weather or rainy weather, and the measurement target 2 can be caused to emit light with the minimum necessary power, thereby saving power.

  Further, the phosphorescent surface material 22 contains inexpensive light-transmitting inorganic particles and can transmit the light emitted by the LED 21a, so that the cost can be reduced and the phosphorescent surface material 22 can be stored by some accident. Even when the amount of light is insufficient and the light emission luminance is insufficient, the light emission luminance of the target can be raised to the appropriate luminance by turning on the LED 21a.

(Fixed point target)
Next, the fixed point target will be described with reference to FIG.
The fixed point target 2 ′ according to the present embodiment includes (a) Example 1: combining black and white squares with a checkered pattern, as shown in FIGS. This is a conventional reflection type target composed of a general reflection checker in which a truncated pyramid is divided into black and white, and a plurality of reflection targets are provided, but in particular, illumination for illuminating the reflection checker surface is not provided. As will be described later, this fixed point target 2 'measures the center point of the fixed point target 2' that has been installed, and the reference obtained by photographing the three-dimensional coordinates measured by this survey and the fixed point target 2 '. Based on the two-dimensional coordinates of the center point of the fixed point target 2 ′ calculated from the image, it is installed for the purpose of confirming the position of the camera 3, which will be described later, and correcting it. This is because it is sufficient to capture images during the daytime in cloudy weather, and there is little need for imaging at night. Further, if the positional deviation of the camera 3 is ignored, the center point of the measurement target 2 before construction (before displacement measurement) is measured, and the fixed point target 2 ′ is determined by using the measured three-dimensional coordinates. It can be omitted.

However, considering the difference in thermal expansion between members due to cold and warm or direct sunlight as a real problem, the positional deviation of the camera 3 installed outdoors is inevitable, and in order to improve the measurement accuracy, as described later, It is desirable to check the positional deviation of the camera 3 for each photographing / measurement and correct the displacement measured from the deviation.
Note that it is sufficient that six or more fixed-point targets 2 ′ are installed. In order to increase measurement accuracy, it is preferable to install many fixed points. In this embodiment, nine fixed-point targets 2 ′ are installed.
Further, the fixed point target 2 ′ is not a conventional reflective target, but may be an internally-illuminated self-luminous target, similar to the measurement target 2 described above.

(Imaging means)
Next, the imaging means will be described (see FIG. 1).
The imaging means according to the present embodiment (see FIG. 1) is a general digital camera, and is connected to a PC 4 (to be described later) via a USB cable or the like, and is photographed at a predetermined time according to a command of a program installed in the PC. It can be used as long as it is possible to perform so-called auto mode shooting that can automatically perform exposure control such as shutter speed and aperture. Further, it may be a camera that shoots a moving image such as a movie.

(Analysis means)
Next, analysis means will be described (see FIG. 1).
The PC 4 which is an analysis unit according to the present embodiment is a general commercially available personal computer, and has a function as an analysis unit that operates as described later by an installed displacement measurement program.
Further, the PC 4 is connected to the camera 3 described above and an external hard disk 5 as an external storage means to be described later so as to be capable of bidirectional communication via a wired or wireless LAN such as a USB cable. It also has a function as a control means for controlling the operation of the hard disk 5.

(External storage means)
Next, the external storage means will be described (see FIG. 1).
The external hard disk 5 that is an external storage unit according to the present embodiment is a general commercially available external hard disk, and has a function of sequentially accumulating and storing images taken by the camera 3 described above. The external hard disk 5 may not be provided when the internal storage means such as an HDD (hard disk drive) provided in the PC 4 has sufficient capacity.
In addition, an image captured by the camera 3 and a measurement result may be printed by connecting a printer to the PC 4.

[Operation of displacement measurement system]
Next, the operation of the displacement measurement system 1 will be described with reference to FIGS. 1 and 5 to 7.
In order to measure displacement with the above-described displacement measurement system 1, it is necessary to set measurement conditions and camera conditions as advance preparations.

(Setting measurement conditions)
The measurement conditions are set according to the flowchart shown in FIG.
(1) Calibration setting In this calibration setting, the color tone, brightness, and the like of an image captured by the camera 3 are calibrated (calibrated) based on an image obtained by capturing a standard pattern.

(2) Orientation process In this orientation process, the two-dimensional coordinates of the center point of the fixed point target 2 'calculated from the reference image obtained by photographing the fixed point target 2' and the center of the fixed point target 2 ' The orientation is performed by comparing the three-dimensional coordinates obtained by actually surveying the points.

(3) Correlation window setting In this correlation window setting, an image correlation method is used in a small region (correlation window) extracted from both the reference image and the captured image, which is used when obtaining three-dimensional coordinates from the image of the three-dimensional image. Set the range (size) to check for matches. When the correlation window size is 15 × 15, “15” is input and set from the keyboard of the PC 4.

(4) Measurement range setting In this measurement range setting, a range in which the displacement of the measurement target 2 and the fixed point target 2 'is measured is set. This measurement range is a pixel unit of the camera 3, and when measuring a range of 20 pixels in length and width, it is set by inputting 20 from the keyboard of the PC 4.

(Camera condition setting)
The camera conditions are set according to the flowchart shown in FIG.
(1) Camera initialization In this camera initialization, the camera 3 is initialized so that it can be photographed through the PC 4.

(2) Shooting condition setting In this shooting condition setting, auto shooting or manual shooting is selected. Auto shooting is a mode in which the shutter speed and aperture of the camera 3 are shot by automatic control of the camera itself, and manual shooting is a mode in which shooting is performed by specifying the shutter speed and aperture values. If manual shooting is selected here, it is necessary to further input and set the shutter speed and aperture values.

(3) Sensitivity setting In this sensitivity setting, the ISO sensitivity of the image sensor of the camera 3 is set between 200 and 1000.

(4) Shooting interval setting In this shooting interval setting, a measurement start time and a measurement end time of displacement measurement are set, and since the measurement is started and repeated until a measurement is completed, a predetermined interval (time) is set. Set the interval time in seconds.

(Displacement measurement)
The displacement of the target is measured according to the setting of the above measurement conditions and the setting of the camera conditions. This displacement measurement is performed according to the flowchart of FIG.
(1) Shooting In step 1, an image including all measurement targets 2 and fixed point targets 2 ′ is shot with the camera 3 in accordance with the shooting instruction of the PC 4.

(2) Image transmission In step 2, the captured image is transmitted from the camera 3 to the PC 4.

(3) Camera position confirmation In step 3, the image transmitted to the PC 4 is analyzed by the PC 4, which is an analysis means, and the center of nine (at least six) fixed point targets 2 ′ obtained from the captured image in the PC 4 Whether or not the installation position of the camera 3 is deviated from the initial position based on the obtained two-dimensional coordinates and the three-dimensional coordinates of the fixed point target 2 ′ and the camera 3 measured by the above-mentioned survey. Is determined, and if there is a deviation, the positional deviation amount is calculated.

(4) Displacement calculation In step 4, the center position of the measurement target 2 is obtained from the image transmitted to the PC 4, the three-dimensional coordinates are calculated therefrom, and the measurement target obtained from the reference image or the previous captured image. The displacement of the measurement target 2 is calculated from the difference from the coordinates.

  Specifically, the correlation coefficient between the reference image and the photographed image is obtained pixel by pixel by template matching for the measurement range determined in the above measurement range setting, and the region having the highest correlation between both images is obtained. The three-dimensional coordinates of the measurement target 2 are calculated by calculating the centroid (center).

  Here, the correlation coefficient is a statistical index indicating the similarity of the two-dimensional luminance distribution between the reference image and the captured image, and when the correlation coefficient is 1, the luminance distribution of both images. Indicates a complete match. Further, when the positional deviation amount of the camera 3 is calculated in step 3, the displacement of the measurement target 2 calculated based on the positional deviation amount is corrected.

(5) Verification of measurement result In step 5, when the correlation coefficient calculated in step 4 is 0.8 or more at all measurement points, it is determined that the measurement is successful, and one measurement point has a correlation coefficient. However, if it is less than 0.8, it is determined that the measurement has failed. If “measurement is successful”, proceed to the next step 6; if “measurement is unsuccessful”, display and save the measurement result via steps 8 and 9, and set the above-mentioned shooting interval setting. Ignoring the interval time, return to step 1 after 1 minute, and perform re-photographing and re-measurement.

(6) Display of measurement results In step 6, the measurement result data analyzed and calculated by the PC 4 is recorded as the shooting date, shooting time, amount of time shift (camera time-PC time, unit is seconds), number of data, PC4 along with the captured image in the order of the longitudinal displacement of the first measurement target, its lateral displacement, its correlation coefficient, the longitudinal displacement of its second measurement target, its lateral displacement, its correlation coefficient,. Output to a monitor (display device) and / or printed out by a printer.

(7) Storage of photographed image and measurement result In step 7, the photographed image and the measurement result are stored and stored in the external hard disk 5, and the measurement is temporarily terminated. Then, when the interval time set in the above-described shooting interval setting has elapsed, shooting / measurement is restarted from step 1.

  In step 8, the measurement result analyzed and calculated by the PC 4 is displayed as in step 6, but a mark such as “#” is displayed in front of the numerical value so that “measurement failure” can be understood at a glance. . In step 9, the captured image and the measurement result are stored in the external hard disk 5 as in step 7.

  In addition, when it is determined that the measurement result is “measurement failure” twice in succession, it is preferable to send an alarm together with the captured image and the measurement result to the registered mail address. At this time, a patrol lamp may be turned on or a warning sound may be emitted at a place where the PC 4 is installed or at a construction office. Further, an alarm may be issued when any displacement of the measurement result exceeds an allowable value.

  Furthermore, when displaying the measurement result data and the captured image on the monitor of the PC 4 in Step 6 or Step 8, it is installed in a construction office or the like away from the place where the PC 4 is installed via the Internet, wired or wireless LAN. It may be possible to browse at all times on the PC. At this time, it is preferable that the measurement result that can be browsed at all times is the latest, and if specified, data of past measurement results can be browsed.

  According to the displacement measuring system 1 according to the embodiment of the present invention described above, since the fluorescent light emitted from the phosphorescent face material 22 is taken as a target, a difference in brightness (contrast) from the surroundings of the target is obtained even at night. Even if the exposure-related settings such as shutter speed and aperture are taken as "auto shooting" mode with the digital camera 3 without taking too large, the exposure accuracy will not be overexposed and the measurement accuracy can be secured. To save time and effort. Further, even during daytime shooting, the target can be recognized regardless of fluctuations in the amount of sunlight and the presence or absence of shadows due to the weather. Therefore, displacement measurement can be performed continuously day and night in the outdoors, and there is little possibility of erroneously recognizing the position of the target during image analysis, and measurement errors can be reduced. Furthermore, even in the case of bad weather such as rainy weather, it is possible to store the light in the phosphorescent face material 22 simply by causing the LED 21a, which is the light emitting means, to emit light, so that the displacement can be measured continuously without being influenced by the weather. .

  In addition, since the phosphorescent surface material 22 which is the light emitting portion of the measurement target 2 is shielded around the circular opening 20a of the case 20 and its optical path becomes circular, it occurs when each measurement target 2 is installed. Regardless of the difference in inclination and angle, there is a region having the highest correlation with the above-mentioned reference image in the photographed image, a perpendicular dividing the line segment connecting two intersections with a certain horizontal line, and the region. Since the intersection of the perpendicular line that bisects the two intersections with the vertical line becomes the centroid of the target, the analysis and calculation to calculate the coordinate position of the target by the PC4 as the analysis means is easy and the program Execution can be performed in a short time, and measurement errors can be further reduced.

  As described above, in the displacement measuring system according to the embodiment of the present invention, the object to be measured is a track (rail), and a plurality of targets according to the embodiment are attached to the side surface of the track, and the displacement of the track is measured. Although described in the case of measurement, it goes without saying that the measurement object is not limited to the trajectory and can be applied to other structures.

  Further, the imaging means, analysis means, external storage means, and the like described as the embodiments can be appropriately changed from other known means. In particular, as an analysis unit, a PC that executes a program that calculates a center point of a target in a photographed image from a correlation coefficient indicating the similarity between two-dimensional luminance distributions between the reference image and the photographed image has been described as an example. The present invention is not limited to a PC that executes such a program, and can be applied to any computer that is programmed so as to be able to measure a change in the position of a target from a captured target image.

1 Displacement measurement system 2 Measurement target (Self-luminous target)
2 'fixed point target 20 case 21 light emitting means 21a LED
22 Phosphorescent material 3 Digital camera (imaging means)
4 PC (analysis means)
5 External hard disk (external storage means)

Claims (6)

A self-luminous target for displacement measurement that is used in a displacement measurement system that measures the displacement of a measurement object by analyzing the image captured by the imaging means, and that emits light by itself attached to the measurement object. ,
A case, a light emitting unit that is attached inside the back side of the case far from the imaging unit, and emits light; a light emitting unit that is attached inside the front side of the case near the imaging unit; A self-luminous target comprising: a phosphorescent surface material that is contained and molded into a plate shape, and stores the light emitted by the light emitting means with the phosphorescent surface material and emits fluorescence toward the imaging means side. .   In the case, a circular hole is formed on the imaging means side, the phosphorescent surface material is attached to the inside of the hole, and the case is shielded from the phosphorescent surface material by shielding a portion other than the hole. The self-luminous target according to claim 1, wherein the self-luminous target emits fluorescence in a circular shape on the imaging means side.   The light-transmitting substance of the phosphorescent surface material is light-transmitting inorganic particles, and the phosphorescent surface material is capable of transmitting light emitted from the light emitting means. The self-luminous target described.   4. The light-emitting means is an LED that emits ultraviolet rays, and the phosphorescent face material contains a phosphorescent phosphor that absorbs ultraviolet rays and emits it as visible light. A self-luminous target according to the above.   The self-luminous target according to any one of claims 1 to 4, an imaging means for imaging the self-luminous target, and an analyzing means for analyzing the image captured by the imaging means and determining the position of the self-luminous target And a displacement measurement system for measuring the displacement of the measurement object from the displacement of the self-luminous target. Having six or more fixed point targets attached to a fixed structure;
The analysis means confirms the positional deviation of the imaging means based on the captured image and the three-dimensional coordinates of the fixed point target actually measured by surveying, and calculates the positional deviation amount. 6. The displacement measurement system according to claim 5, wherein the displacement of the measurement object measured based on the amount is corrected.

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