JP2010230482A - Pile rebound amount measuring device and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device and method for measuring a pile rebound quantity without requiring a measurement of distance when the pile rebound quantity is measured using an optical measuring device such as a CCD camera. <P>SOLUTION: The pile rebound quantity measuring device includes a camera 11 having an image sensor, and a calculation processing device 14 for performing a calculation processing based on the electric signal from the image sensor. The camera is placed apart from the pile to be driven installed with a target having a measuring standard part and a known size part for which the size is known so as to take an image of a predetermined region containing the target, and the calculation processing device including a first calculation part 21 for calculating a conversion coefficient representing the relation between the electric signal from the camera and the size of the target, based on the electric signal output by taking an image of the known size part of the target by the camera, and a second calculation part 21 for calculating so as to convert to an amount of displacement of the measuring standard part by the driving of the pile using the conversion coefficient output by imaging the measuring standard part of the target. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a pile rebound amount measuring apparatus and a pile rebound amount measuring method for measuring a rebound amount at the time of placing a pile.

  In construction work such as steel pipe piles at sea, the penetration and rebound quantity per steel pipe pile placement are measured as the judgment of the stop of the steel pipe pile to be placed. Moreover, the bearing capacity of the steel pipe pile piled up using these measured values is calculated. Conventionally, for this measurement, an operator manually attaches a graph paper to a steel pipe pile near the end of pile driving and presses a pencil against the graph paper.

  Recently, a method of measuring the amount of penetration and the amount of rebound by measuring the position of a mark or reflective tape provided on a steel pipe pile as a displacement amount by an optical measuring device such as a CCD camera is known (for example, , See Patent Documents 1 to 3 below).

Japanese Examined Patent Publication No. 7-81273 JP-A-11-344396 Japanese Patent No. 3655365

  However, according to the measurement method using a conventional CCD camera, the measurement value changes depending on the measurement distance between the reflective tape / mark on the steel pipe pile and the CCD camera. It was necessary to decide. In actual measurement, the measurement distance between the reflective tape or mark of the steel pipe pile and the CCD camera is not constant, so each time, the measurement distance is measured with a distance measuring instrument and the correction value of the measurement amount is determined. It has occurred. For this reason, it has been a result that it takes time to measure the rebound amount and the like in the construction work such as steel pipe piles.

  In view of the above-described problems of the prior art, the present invention provides a pile rebound amount measuring apparatus and method that eliminates the need to measure the measurement distance when measuring the rebound amount of a pile using an optical measurement device such as a CCD camera. The purpose is to provide.

  In order to achieve the above object, the pile rebound amount measuring device according to the present embodiment is based on a camera having an image sensor that converts an amount of captured light into an electrical signal and outputs the electrical signal, and an electrical signal from the image sensor. A pile rebound amount measuring device for measuring the rebound amount of the pile, wherein the camera has a known measurement reference part and dimensions for measuring the displacement amount of the pile. It is installed so as to image a predetermined region including the target at a position away from a pile to be placed provided with a target having a certain dimension known portion, and the arithmetic processing unit is configured so that the target dimension is known by the camera. A first calculation for calculating a conversion coefficient representing a relationship between an electric signal from the camera and a dimension at the target, based on an electric signal output by imaging the unit And a second computing unit that computes from the electrical signal output by imaging the measurement reference part of the target and using the conversion coefficient to convert the displacement to the displacement of the measurement reference part by driving the pile, It is characterized by having.

  According to this pile rebound amount measuring device, the first calculation unit of the calculation processing device can automatically calculate the conversion coefficient based on the electrical signal output from the camera that images the target dimension known portion, 2 The displacement of the measurement reference part can be obtained by converting the measurement reference part to the displacement of the measurement reference part from the electrical signal output by imaging the measurement reference part of the target using the conversion factor. It is not necessary to measure the measurement distance to the target.

  In the pile rebound amount measuring apparatus, the image sensor is composed of a line sensor having a predetermined number of pixels, and the first calculation unit captures an image of a known dimension of the target and outputs an electrical signal output from the line sensor. A size per bit can be calculated as the conversion coefficient from the number of bits corresponding to the pixel and the known size.

  Preferably, the target is made of a reflective tape having a predetermined width, an edge of the reflective tape is used as the measurement reference portion, and the predetermined width is used as the known dimension portion. In addition, it is preferable to provide the irradiation means for irradiating the said predetermined area | region.

  In addition, the penetration amount and the rebound amount of the pile for each placement can be obtained from the displacement amount of the measurement reference portion calculated as described above.

  The pile rebound amount measuring method according to the present embodiment is a pile rebound amount measuring method for measuring the rebound amount of the pile, and a measurement reference part for measuring the displacement amount of the pile and a dimension known part whose dimensions are known; A target having a target is provided on a pile to be placed, and a camera having an image sensor that converts the amount of captured light into an electrical signal and outputs the image is captured at a position away from the pile. And the arithmetic processing unit represents the relationship between the electrical signal from the camera and the dimensions of the target based on the electrical signal output by imaging the known dimension part of the target with the camera. The amount of displacement of the measurement reference portion due to the driving of the pile using the conversion factor from the electrical signal calculated by calculating the conversion factor and imaging the measurement reference portion of the target Characterized in that it converted.

  According to this pile rebound amount measuring method, the arithmetic processing device can automatically calculate the conversion coefficient based on the electrical signal output from the camera that has captured the known dimension of the target, and the conversion coefficient can be used. The displacement of the measurement reference part can be obtained by converting the electrical signal output by imaging the measurement reference part of the target and converting it into the displacement of the measurement reference part. Therefore, the measurement distance between the camera and the target can be measured. It becomes unnecessary.

  In the pile rebound amount measuring method, the image sensor is configured from a line sensor having a predetermined number of pixels, and the arithmetic processing unit captures the dimension known portion of the target and outputs the electrical signal output from the line sensor. A dimension per bit can be calculated as the conversion coefficient from the number of bits corresponding to the pixel and the known dimension.

  Preferably, the target is made of a reflective tape having a predetermined width, an edge of the reflective tape is used as the measurement reference portion, and the predetermined width is used as the known dimension portion. It is preferable that the predetermined area is irradiated when the predetermined area is imaged by the camera.

  According to the pile rebound amount measuring apparatus and method of the present invention, measurement of the measurement distance between the camera and the target (pile) can be made unnecessary in the measurement of the rebound amount of the pile. Therefore, even if the measurement distance between the camera and the target (pile) changes in the pile construction work, the rebound amount can be measured quickly.

It is a figure which shows roughly the whole structure of the pile rebound amount measuring apparatus by this embodiment. It is a block diagram which shows roughly the pile rebound amount measuring apparatus of FIG. It is a figure which shows schematic structure of the CCD camera of FIG. 1, FIG. It is a figure which shows roughly the camera visual field containing the reflective tape affixed on the pile of the measuring object of FIG. It is a schematic diagram of the digital signal input into the personal computer from the A / D converter of the pile rebound amount measuring apparatus of FIG. It is the schematic which shows the measurement result for one hit to the pile by the pile rebound amount measuring apparatus of FIG. It is a flowchart for demonstrating measurement process S01-S11 of the pile rebound amount by the pile rebound amount measuring apparatus 10 of FIGS. It is a figure which shows the measurement result in a present Example by the relationship between the time when placement is performed, and the displacement amount of a pile.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. FIG. 1 is a diagram schematically showing an overall configuration of a pile rebound amount measuring apparatus according to the present embodiment. FIG. 2 is a block diagram schematically showing the pile rebound amount measuring apparatus of FIG. FIG. 3 is a diagram showing a schematic configuration of the CCD camera shown in FIGS.

  As shown in FIGS. 1 and 2, the pile rebound measuring device 10 controls the CCD camera 11 having a line sensor composed of a CCD image sensor and the CCD camera 11 and receives various electric signals from the CCD camera 11 to perform various processes. A controller 12 to perform, an A / D converter (A / D) 13 that converts an analog signal from the controller 12 into a digital signal, and a personal computer that receives the digital signal from the A / D converter 13 and performs arithmetic processing, etc. (Computer) 14 and an irradiation unit 15 having a halogen light.

  As shown in FIG. 1, the pile P that is the measurement target of the pile rebound amount measuring device 10 is driven in the downward direction D by hitting the hydraulic hammer HA from the water surface S to the bottom of the water.

  As shown in FIG. 1, the CCD camera 11 is installed using a tripod 36 or the like at a predetermined position away from the stake P to be measured, and the reflection tape RT attached to the stake P is used as a target. The area AR on the included pile P is imaged, and the irradiation unit 15 irradiates the area AR with the light of the halogen light.

  As shown in FIG. 3, the CCD camera 11 includes a lens unit 16 and a CCD (charge coupled device) line sensor 17. The CCD line sensor 17 includes an imaging unit 18 made of a photodiode, a transfer unit 19 made of a shift register, and an output unit 20 that outputs an electrical signal. The imaging unit 18 and the transfer unit 19 are arranged in a line. It consists of

  When the light from the subject IM forms an image on the imaging unit 18 through the lens unit 16, the CCD line sensor 17 accumulates electric charges, and when the parallel transfer pulse from the outside is turned on, it is transferred to the shift register of the transfer unit 19 and output. An electric signal is output from the unit 20 as a time-series pulse. The imaging unit 18 includes a large number of finely formed photodiodes. Each photodiode constitutes one pixel, and a pulse signal output in the arrangement order of the photodiodes corresponds to each pixel.

  As shown in FIG. 2, the personal computer 14 calculates the conversion coefficient by the first calculation unit 21 based on the digital signal input through the input unit 14a, stores the conversion coefficient in the memory 24 such as a RAM, and the like. At the same time, the second calculation unit 22 calculates the displacement amount due to the driving of the pile based on the input digital signal and the conversion coefficient read from the memory 24, and the calculation result is displayed on the display unit 25 including a liquid crystal panel or the like. To display. The calculation result is output to a recording medium by an externally connected printer 27.

  The personal computer 14 has a control unit 26 composed of a CPU (Central Processing Unit). A program, which is software for executing the above-described calculation, is installed in the personal computer 14, and this program is read out during use and operates when the CPU operates to perform a predetermined calculation process. ing. The personal computer 14 has a pointing device such as a mouse and an input unit such as a keyboard.

  Next, the measurement of the displacement amount of the pile by the pile rebound amount measuring device of FIGS. 1 to 3 will be described with reference to FIGS. 4, 5, and 6. FIG. 4 is a diagram schematically showing a camera field of view including a reflective tape affixed on the pile to be measured of FIG. FIG. 5 is a schematic diagram of a digital signal input to the personal computer from the A / D converter of the pile rebound amount measuring apparatus of FIG. FIG. 6 is a schematic view showing a measurement result for one hit to the pile by the pile rebound amount measuring device of FIG.

  As shown in FIG. 4, an elongated reflective tape RT having a predetermined width w is pasted in the circumferential direction of the pile P on the portion above the water surface of the pile P to be placed in FIG. 1. The reflection tape RT has a high light reflection efficiency on the surface due to the surface treatment, the surface structure, and the like, and the light reflectance is considerably higher than that of the surface of the pile P. A commercially available reflective tape RT can be used.

  The field of view of the CCD camera 11 in FIGS. 1 to 3 is, for example, 5120 bits, which is the number of effective pixels of the CCD line sensor 17, and the pile rebound amount measuring device 10 is positioned at what bit the reflected light from the reflective tape RT is positioned in the camera field of view. Measure what to do.

  As shown in FIGS. 1 and 4, the CCD camera 11 is set so that the area AR including the reflective tape RT attached to the stake P becomes the camera field of view, and fixed at a predetermined position. Irradiation is performed with halogen light from the irradiation unit 15. When the CCD camera 11 images the area AR, the CCD camera 11 crosses the reflective tape RT at points B and C from the point A (scanning start point) of the camera field of FIG. ) At a predetermined scanning cycle (for example, 1 msec), and the image data is repeatedly acquired along the line L from the point A to the point D by such scanning.

  The digital signal as shown in FIG. 5 is output in time series from the A / D converter 13 shown in FIGS. 1 and 2 and input to the personal computer 14 by the above-described scanning once. This is because the reflected light from the reflective tape RT is incident on the CCD line sensor 17, and its bit width w ′ corresponds to the width w of the reflective tape RT.

  In FIG. 5, a point A (scanning start point) in the camera field of view corresponds to 0 bit, a point D (scanning end point) corresponds to, for example, 5120 bits, and a point B on one edge of the reflective tape RT having a width w (mm). Bbit and the other edge point C corresponds to cbit, the first calculation unit 21 of the personal computer 14 calculates a conversion coefficient K (mm / bit) representing the distance per 1 bit (1 pixel) from the following equation (1). Calculate.

  K = w / (c−b) (1)

  Further, the position Lb (the distance (mm) from the point A to the point B) of the point B on the edge of the reflective tape RT is calculated from the following equation (2) using the conversion factor K described above by the second calculation unit 22.

  Lb = K × b (2)

  Here, the pile P in FIG. 1 is moved downward by being hit by the hydraulic hammer HA, the reflective tape RT moves to the position indicated by the broken line in FIG. 4, and the rising signal is indicated by the broken line in FIG. Is moved between B ′ and C ′, and the point B ′ corresponds to b′bit, the position Lb ′ (mm) of the point B ′ at the edge of the reflecting tape RT after the movement is the same as in the equation (2). Can be calculated from the following equation (3).

  Lb ′ = K × b ′ (3)

  The displacement ΔL (mm) of the pile P due to the movement of the point B → B ′ (point C → C ′) is calculated from the following equation (4) by the second calculation unit 22 using the calculation result.

  ΔL = Lb′−Lb (4)

  The displacement amount ΔL of the pile P measured as described above varies depending on the placement of the pile P as shown in FIG. That is, FIG. 6 shows that the displacement amount ΔL obtained from the above equation (4) fluctuates with the time t before and after hitting the pile P. The displacement amount ΔL is the displacement amount ΔL1 (minimum value before hitting). ) To the maximum displacement amount ΔL2 due to impact and then decreases to the displacement amount ΔL3 (minimum value). At this time, the rebound amount LB (mm) is calculated from the following equation (5), and the penetration amount LK is also calculated. (Mm) is calculated from the following equation (6).

LB = ΔL2−ΔL3 (5)
LK = ΔL3-ΔL1 (6)

  Changes in the displacement amount ΔL of the pile at the time of placing the pile P can be displayed on the display unit 25 of the personal computer 14 in the form of a graph. Further, as shown in FIG. Can output.

  In addition, the second calculation unit 22 calculates the rebound amount LB and the penetration amount LK for each impact by the above formulas (5) and (6), and displays them on the display unit 25 of the personal computer 14 in a graph format or a table format. The printer 27 may output the recording paper or the like. For this purpose, the personal computer 14 automatically acquires the minimum value of the displacement amount ΔL1 before hitting, the maximum displacement amount ΔL2 and the minimum value of the displacement amount ΔL3 after hitting shown in FIG.

  Next, measurement steps S01 to S12 of the pile rebound amount by the pile rebound amount measuring apparatus 10 of FIGS. 1 to 3 will be described with reference to FIG. FIG. 7 is a flowchart for explaining pile rebound amount measurement steps S01 to S11 by the pile rebound amount measuring apparatus 10 of FIGS.

  First, the reflective tape RT is affixed to the pile P to be measured as shown in FIG. 1 (S01). Next, each power source of the controller 12, the personal computer 14, and the irradiation unit 15 in FIG. 1 is turned on (S02), and measurement pre-setting such as setting of measurement time and input of the reflective tape width w is performed (S03), and the reflective tape RT In contrast, the focus of the CCD camera 11 is adjusted (S04).

  Next, when approaching the stop of the driving of the pile P, the measurement start is turned on by the controller 12 (S05), the measurement is started (S06), and the hammer P is repeatedly hit by the hydraulic hammer HA. Automatic measurement is performed by the CCD camera 11 (S07). This measurement time is set in step S03 and is, for example, about 20 to 30 seconds.

  Based on the first measurement data measured by the CCD camera 11, the conversion coefficient is calculated by the personal computer 14 as described above (S08), and then the second and subsequent measurement data are recorded (S09), and the set measurement time elapses. This completes the measurement (S10).

  Next, the measurement result is output to the recording paper by the printer 27 (S11). This output can be output, for example, as a graph showing the relationship between time and the amount of displacement of the pile as shown in FIG. In this case, the change amount of the bit data may be output. For example, the position of the displacement scale and the scale value on the vertical axis in FIG.

  As described above, according to the pile rebound amount measuring apparatus 10 of FIGS. 1 to 3, the conversion coefficient K representing the length per bit is automatically calculated in the personal computer 14 by measuring the width w of the reflective tape RT. And calculating the displacement from the number of bits corresponding to the edge of the reflective tape RT using the conversion coefficient K, regardless of the measurement distance between the CCD camera 11 and the reflective tape RT of the pile P. , Pile displacement can be obtained automatically. For this reason, it is not necessary to determine the measurement value correction value by separately measuring the measurement distance with a distance measuring instrument or the like as in the prior art.

  In addition, even if the installation position of the CCD camera 11 or the position of the pile P to be measured changes and the measurement distance changes, the conversion factor is automatically calculated by measuring the width w of the reflective tape RT. It is possible to quickly measure the amount of rebound and penetration during construction.

  EXAMPLES Next, although an Example demonstrates this invention concretely, this invention is not limited to a present Example.

The measurement conditions of the examples are as follows.
When placing a steel pipe pile with a diameter of 800 mm on the seabed, it was measured on land about 15 m away. The CCD camera used is a NED e5150-F (5150 pixels) with a minimum scan period of 80 / 12.5 (μs / kHz), and the controller is a NED MEGA40 (line scan camera controller external input / output: parallel 32bit, RS232C analog output) The reflective tape was white and super bright.

  The measurement results are shown in FIG. During the measurement time of 0 to 20 seconds, the hammer was repeatedly hit by the hydraulic hammer HA, and the displacement of the pile during that time changed as shown in the figure. In the figure, A is the rebound amount at the first placement and B is the penetration amount. For comparison, the conventional manual measurement was performed as follows. Affix the graph paper (A4 size) to the stake, press the pencil against any point on the graph paper, then start placing, and perform manual measurement while moving the pencil horizontally for each stroke with the hydraulic hammer HA It was. As a result, the result almost coincided with the measurement result of FIG.

  As described above, the modes for carrying out the present invention have been described. However, the present invention is not limited to these, and various modifications can be made within the scope of the technical idea of the present invention. For example, in FIGS. 4 and 5, the displacement amount at the time of driving the pile is measured with reference to the point B on one edge of the reflective tape RT, but it may be based on the point C on the other edge. Of course. The width of the reflective tape RT may be an arbitrary width, for example, 20 to 50 mm, but is not limited thereto. Moreover, the target provided in a pile is not limited to a reflective tape, Although another structure may be sufficient, a thing with a higher reflectance than a pile surface is preferable.

  In the CCD camera 11 of FIG. 1, an area sensor may be used instead of the line sensor. However, the line sensor is preferable because the number of pixels in one line can be increased and the resolution is high and high-speed processing is possible. In addition, a camera using a CMOS line sensor may be used as the camera 11.

  According to the pile rebound amount measuring apparatus and method of the present invention, measurement of the measurement distance between the camera and the target can be made unnecessary in the measurement of the rebound amount of the pile, and even if the measurement distance changes in the pile placing work. Since the amount of rebound can be measured quickly, the efficiency of the pile driving work can be improved.

10 Pile rebound measuring device 11 CCD camera 14 Personal computer (processing unit)
17 Line sensor 21 First calculation unit 22 Second calculation unit ΔL Pile displacement LB Rebound amount LK Penetration amount P Pile RT Reflective tape w Reflective tape width

Claims (6)

A camera having an image sensor that converts the amount of captured light into an electric signal and outputs the signal, and an arithmetic processing device that performs arithmetic processing based on the electric signal from the image sensor, and measures the amount of rebound of the pile A pile rebound amount measuring device for
The camera picks up a predetermined area including the target at a position away from a pile to be placed in which a target having a measurement reference part for measuring a displacement amount of the pile and a known dimension part having a known dimension is provided. Installed to
The arithmetic processing unit calculates a conversion coefficient that represents a relationship between an electrical signal from the camera and a dimension at the target, based on an electrical signal output by imaging a known dimension of the target with the camera. An arithmetic unit;
A second computing unit that computes from the electrical signal output by imaging the measurement reference part of the target, using the conversion coefficient to convert the displacement into the displacement of the measurement reference part due to the driving of the pile. Pile rebound amount measuring device characterized by that. The image sensor is composed of a line sensor having a predetermined number of pixels,
The first arithmetic unit captures a dimension per bit from the number of bits corresponding to the pixel and the known dimension of the electrical signal output from the line sensor by imaging the dimension known part of the target as the conversion factor. The pile rebound amount measuring apparatus according to claim 1 to calculate. The target is composed of a reflective tape having a predetermined width,
The pile rebound amount measuring device according to claim 1 or 2, wherein an edge of the reflective tape is used as the measurement reference part, and the predetermined width is used as the dimension known part. A pile rebound amount measuring method for measuring a pile rebound amount,
A target having a measurement reference part for measuring the displacement amount of the pile and a known dimension part having a known dimension is provided on the pile to be placed,
A camera having an image sensor that converts and outputs the amount of captured light into an electrical signal is installed so as to capture a predetermined area including the target at a position away from the pile,
An arithmetic processing unit calculates a conversion coefficient representing the relationship between the electrical signal from the camera and the size of the target, based on the electrical signal output by imaging the known dimension portion of the target with the camera. And the pile rebound amount measuring method characterized by converting into the displacement amount of the said measurement reference | standard part by the placement of the said pile using the said conversion factor from the electrical signal which imaged and output the measurement reference | standard part of the said target. The image sensor is composed of a line sensor having a predetermined number of pixels,
The arithmetic processing unit calculates a size per bit as the conversion factor from the number of bits corresponding to the pixel and the known size of an electrical signal output from the line sensor by imaging a known size portion of the target. The pile rebound amount measuring method according to claim 4. The target is composed of a reflective tape having a predetermined width,
The pile rebound amount measuring method according to claim 4 or 5, wherein an edge of the reflective tape is used as the measurement reference part, and the predetermined width is used as the dimension known part.

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