JPH1038531A - Method and device for automatically measuring pipe shape - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain accurate shape information on a pipe structure even when a pipe structure shape is significantly different from the drawing. SOLUTION: A direct action 3-axis driving mechanism comprises an direct acting X-axis 101, a direct acting Y-axis 102, a direct action Z-axis 103 and a pillar, driven in cross 3-axis type. A rotary 3-axis driving mechanism 105 is attached to a tip of the direct action Z-axis 103, driven in roll angle, pitch angle and yoke angle rotation type. A visual sensor device 106 attached to the tip of the rotary 3-axis driving mechanism 105, a slit laser is projected on a sample pipe, and the reflection light of the slit laser projected on the pipe surface is imaged with a CCD camera. A control device 107 controlling the direct action 3-axis driving mechanism and the rotary 3-axis driving mechanism 105, moves the visual sensor device 106 to an arbitrary position, and rotates it to an arbitrarty posture. A shape analyzing device 108 processes the image of the visual sensor device 106 for obtaining a 3D shape of pipe, and displays it on a CRT 112.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic pipe shape measuring apparatus and a measuring method applied to general pipe structures such as ships and boiler products.

[0002]

2. Description of the Related Art Heretofore, regarding pipe shape measurement,
There is no device that automatically obtains the shape information of the entire pipe structure.In the manufacture of pipe structures, when performing assembly, welding, etc., the worker checks the approximate shape from the design drawing, and the exact position and dimensions All adjustments are done manually by site adjustment.

[0003]

Conventionally, there have been the following problems in manufacturing a pipe structure. (1) The pipe structure has a large manufacturing error due to the effects of deformation and bending return when the pipe is bent, assembling error when piping, and the like.

[0004] (2) Even if the design drawing is CAD / CAM data, it is necessary to perform site adjustment by an operator after pipe bending for the reason of (1), and it is difficult to automate the production of pipe structures. there were.

(3) Manufacture of a pipe structure by site adjustment by an operator requires skill of the operator, and it is difficult to stabilize the quality. The present invention has been made to solve the above problems,
Even if the shape of the pipe structure has a large error from the design drawing, the local part of the pipe structure is automatically measured and the entire shape of the pipe structure is restored from the measured local data. Accordingly, an object of the present invention is to provide a pipe shape automatic measuring device and a measuring method capable of obtaining accurate shape information of the pipe structure.

[0006]

In order to achieve the above object, an automatic pipe shape measuring apparatus according to the present invention automatically measures the shape of a bent pipe structure, and comprises a plurality of pipe structures. A measuring device that measures the cross-sectional shape of a location, a drive mechanism and control device that moves the measuring device along the pipe structure, and a shape that analyzes the overall shape of the pipe structure from the measured cross-sectional shape data of multiple locations An analyzer is provided.

Further, according to the automatic pipe shape measuring method according to the present invention, a cross-sectional shape of a pipe structure at a plurality of positions is measured by a measuring device, and the measuring device is moved along the pipe structure by a driving mechanism. It is characterized in that the shape of the entire pipe structure is analyzed from the cross-sectional shape data of a plurality of locations measured by the equipment.

(Operation) The present invention moves a measuring device such as a visual sensor attached to the tip of a driving mechanism along a pipe at a fixed distance from the surface of the pipe, thereby making the local cross-sectional shape of the pipe continuous. Then, the pipe structure is output as continuous curved surface shape information by restoring the entire shape of the pipe structure by arithmetic processing such as spline interpolation.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. <Configuration of automatic pipe shape measuring device>
FIG. 2 is an enlarged view of a rotary three-axis driving mechanism and a visual sensor device described later.

The present apparatus has three linear drive mechanisms 101 to 10.
4, rotation three-axis drive mechanism 105, visual sensor device 106,
Further, it comprises a control panel 107 for storing a control device 107 and a shape analysis device 108.

The above-mentioned linear motion three-axis driving mechanism includes a linear motion X-axis 10
1. Linear Y-axis 102, linear Z-axis 103, and support 104
, And can be driven in an orthogonal three-axis system.

The rotary three-axis driving mechanism 105 is attached to the end of the direct-acting Z-axis 103 of the direct-acting three-axis driving mechanism.
As shown in detail in FIG. 2, the rotation α axis 201 and the rotation β axis 20
2. It is composed of a rotating γ axis 203 and can be driven in a roll angle, pitch angle, and yaw angle rotation type.

As shown in FIG. 2, the visual sensor device 106 is attached to the tip of a rotating three-axis driving mechanism 105,
It comprises a slit laser projector 204 and a CCD camera 205, projects a slit laser 206 onto a pipe 207 to be measured, and reflects the reflected light of the slit laser 206 reflected on the surface of the pipe 207 into the CCD camera 205.
Can be taken.

The slit laser projector 204 has a main wavelength of 6
The specifications are 80 nm and the output is 20 mW. The CCD camera 205 is provided with an interference filter that provides a filtering effect of a half-width of 10 nm centered on 680 nm, which is the same wavelength as the main wavelength of the slit laser projector 204, and removes disturbance light such as a fluorescent lamp or welding arc light. Then, only the reflected light of the slit laser 206 can be imaged.

The control device 107 is installed inside the control panel 109, controls the direct-acting three-axis driving mechanism 101 and the rotating three-axis driving mechanism 105, and moves the visual sensor device 106 to an arbitrary position (XYZ) in a three-dimensional space. ), And can be rotated to an arbitrary posture (roll angle, pitch angle, yaw angle).

The shape analyzing device 108 is installed inside the control panel 109, and can process an image captured by the visual sensor device 106 to obtain a three-dimensional shape of the pipe 207 as an object to be measured.

The pipe structure 110 to be measured is:
It is fixed on a gantry 111. <Method of Obtaining Pipe Shape Information> Next, a method of obtaining pipe information by the present apparatus will be described in detail in order.

(1) Obtaining Pipe Section Image FIG. 3 shows the visual sensor device 106 and the pipe 207 to be measured.
FIG.

Reference numeral 207 denotes a pipe to be measured of a pipe structure installed in the apparatus. Reference numeral 301 denotes the origin of the absolute coordinate system of the apparatus. 303 is a pipe 207 to be measured
Is the point of interest set at the center of.

Reference numeral 304 denotes a pipe direction vector extending from the point of interest 303 in the longitudinal direction of the pipe 207 to be measured. Reference numeral 305 denotes a tip of the rotation α-axis of the rotation three-axis drive mechanism. The position and direction of this tip are determined by the slit laser projector 2
The central axis of 04 passes through the point of interest 303, is orthogonal to the pipe direction vector 304, and the distance between the slit laser projector 204 and the point of interest is constant. The positional relationship between the visual sensor device 106 and the measurement target is satisfied.

Reference numeral 306 denotes an imaging range of the CCD camera 205, which is located in a two-dimensional space on a plane formed by the slit laser 206. The imaging range 306 has been adjusted in advance to a size such that the pipe section to be measured is sufficiently imaged.

Reference numeral 307 denotes a measurement trajectory for continuously measuring the cross section of the pipe.
And the positional relationship between the measurement target pipe 207 is satisfied. The measurement trajectory 307 is obtained by the control device automatically calculating based on the CAD data of the pipe structure, or obtained by a teaching operation in which the operator manually operates the direct-acting three-axis driving mechanism and the rotating three-axis driving mechanism. is there.

FIG. 4 shows an image of the cross section of the pipe captured by the CCD camera 205. The pipe cross-sectional image shown in FIG.
The slit laser 20 is moved along the visual sensor device 106 at a constant interval according to the measurement trajectory 307.
6 is projected onto the surface of the pipe 207, and the reflected light of the slit laser 206 reflected on the surface of the pipe 207 is continuously captured by the CCD camera 205. In the present embodiment, the slit laser 206 is projected onto the pipe surface to obtain pipe section information.
m, and the pitch was 15 mm at the bent portion.

The cross-sectional image of the pipe shown in FIG. 4 is generated by the slit laser 206 on the pipe surface due to the effect of the interference filter attached to the CCD camera 205 described above.
Is a laser line in which only the reflected light is imaged, and becomes a pipe cross-sectional image as if the pipe 207 was cut by the slit laser 206.

When the pipe outer circumference data of 100 ° or more is obtained, the center coordinates of the pipe 207 described later can be obtained. (2) Acquisition of Laser Line Point Sequence Coordinates FIG. 5 shows a laser line point sequence coordinate diagram of a pipe cross section.

Reference numeral 501 denotes an origin of a relative two-dimensional coordinate system viewed from the CCD camera 205. Reference numeral 502 denotes a point sequence group (x _i , y _i ) of laser lines (i = 0, 1, 2, 3,...)
Is a sequence of points on the relative two-dimensional coordinate system viewed from the CCD camera 205. Since the positional relationship between the slit laser projector 204 and the CCD camera 205 is known, this dot sequence can be obtained by using a light cutting method applying the principle of triangulation.

(3) Calculation of the coordinates of the center of the pipe cross section FIG. 6 shows an approximate ellipse of the pipe cross section. 601
Is the center coordinates (x _c , y _c ) of the pipe section calculated from the laser line point sequence (x _i , y _i ) 502 using an ellipse approximation [Equation 7] using the least square method described later. , C
This is a point on the relative two-dimensional coordinate system viewed from the CD camera 205.

Since the shape of the pipe structure to be measured has a large error with respect to the design drawing by using the elliptic approximation formula [Formula 7], the slit laser 206 is used in the measurement trajectory 307 calculated from the CAD data of the pipe structure. Even if the pipe is not projected perpendicularly to the pipe 207, the pipe cross-sectional shape is theoretically elliptical, so that the center coordinates 601 of the pipe cross-section can be obtained more accurately than the pipe cross-section is approximated by a circle.

Reference numeral 602 denotes an approximate ellipse having the center coordinates (x _c , y _c ). Since the elliptic approximate expression includes a circular approximate expression, when the slit laser 206 is projected perpendicularly to the pipe 207, it approaches a perfect circle. .

Next, an elliptic approximation formula using the least squares method will be described. [Elliptic Approximation Equation] The elliptic equation can be expressed as the following equation in consideration of the inclination θ of the ellipse with respect to the orthogonal axis of the two-dimensional coordinates (x, y).

[0031]

(Equation 1) Here, if u and v are eliminated with α = cos θ and β = sin θ, a linear combination polynomial in which a, b, c, d, e, and f are unknowns is obtained.

[0032]

(Equation 2)

[0033]

(Equation 3) Holds. From [Equation 2] and [Equation 3],

[0034]

(Equation 4) Becomes Here, the measurement point sequence (x _i, y _i) is solved by the least square method using,

[0035]

(Equation 5) Than this,

[0036]

(Equation 6) Ξ1, ξ2, ξ3, ξ4 are determined by solving. Therefore, the center coordinates (x _c , y _c ) of the ellipse are obtained as follows.

[0037]

(Equation 7)

(4) Restoration of Pipe Shape FIG. 7 shows a restored shape diagram of a pipe to be measured. 701
Are the linear motion three-axis XYZ position and the rotation 3 when measuring the two-dimensional coordinate system center coordinates (x _c , y _c ) for each pipe section described above.
Based on the shaft αβγ angle information, variable operation has been centered coordinates in the three-dimensional coordinate system _{(X c, Y c, Z} c) is.

Reference numeral 702 denotes the center coordinates (X _c , Y _c , Z _c )
701 is a sectional circle of a pipe forming a pipe surface centered on 701. The pipe section circle is a perfect circle on a plane having a diameter equal to the design pipe diameter and orthogonal to a pipe center curve 703 described later.

Reference numeral 703 denotes a center coordinate (X) of each pipe section.
_c , Y _c , Z _c ) 701 using spline interpolation.
It is a pipe center curve connected for every pipe. 704
Is a pipe cross-section circle 702 centered on the pipe center curve.
Is a curved surface of a continuous pipe surface.

By the above operation, the automatic pipe shape measuring apparatus of the present invention measures the bent shape of the pipe structure and acquires the pipe center curve 703 and the pipe surface curved surface 702 as pipe shape information. This restored shape diagram is displayed on the CRT 112 in FIG.

[0042]

As described above in detail, according to the present invention, even if the shape of the pipe structure has a large error from the design drawing, the actual pipe structure is automatically measured and its shape information is obtained. To obtain the pipe structure again by CAD
/ CAM, which eliminates the need for an operator to perform on-site adjustment after the measurement, thereby making it possible to streamline the production of pipe structures.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an automatic pipe shape measuring apparatus according to an embodiment of the present invention.

FIG. 2 is an enlarged view of a rotary three-axis drive mechanism and a visual sensor device according to the embodiment.

FIG. 3 is a diagram showing a positional relationship between the visual sensor device and the pipe to be measured according to the embodiment.

FIG. 4 is an image diagram of a cross section of a pipe taken by the CCD camera according to the embodiment, and is a photograph of a halftone image displayed on a display.

FIG. 5 is a laser line point sequence coordinate diagram of a pipe cross section according to the embodiment.

FIG. 6 is an approximate elliptical view of a cross section of the pipe according to the embodiment.

FIG. 7 is a restored shape diagram of the pipe to be measured according to the embodiment;

[Explanation of symbols]

 101 linear motion three-axis drive mechanism (linear motion X-axis) 102 linear motion three-axis drive mechanism (linear motion Y-axis) 103 linear motion three-axis drive mechanism (linear motion Z-axis) 104 linear motion three-axis drive mechanism (support) 105 Rotary three-axis drive mechanism 106 Visual sensor device 107 Control device 108 Shape analysis device 109 Control panel 110 Pipe structure 111 Mount 112 CRT 201 Rotation α-axis 202 Rotation β-axis 203 Rotation γ-axis 204 Slit laser projector 205 CCD camera 206 Slit laser 207 Pipe to be measured

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroshi Tsurusaki 1-1, Akunouracho, Nagasaki-shi, Nagasaki Mitsubishi Heavy Industries, Ltd. Nagasaki Shipyard

Claims (4)

[Claims] An apparatus for automatically measuring the shape of a bent pipe structure, comprising: a measuring device for measuring a plurality of cross-sectional shapes of the pipe structure; and moving the measuring device along the pipe structure. An automatic pipe shape measuring apparatus, comprising: a drive mechanism for controlling the same; and a control device for the same; and a shape analyzing device for analyzing a shape of the entire pipe structure from measured cross-sectional shape data at a plurality of locations. 2. The pipe shape automatic measuring device according to claim 1, wherein the measuring device includes a visual sensor. 3. The automatic pipe shape measuring apparatus according to claim 1, wherein the measuring device includes a slit laser projector and a CCD camera. 4. A method for automatically measuring the shape of a bent pipe structure, wherein a cross-sectional shape of a plurality of portions of the pipe structure is measured by a measuring device, and the measuring device is connected to the pipe structure by a driving mechanism. A pipe shape automatic measuring method characterized by analyzing the shape of the entire pipe structure based on cross-sectional shape data of a plurality of locations measured by the measuring device.