JPH03170812A - Measuring apparatus for dimension of structural member - Google Patents

Abstract

PURPOSE:To measure the size of a member necessary for numerical temporary assembly with high accuracy by supporting a multi-functional sensor head with a three-axis positioning arm, and providing a scanning device, a tracing target and a three-dimensional position measuring device. CONSTITUTION:A multi-functional sensor head 16 illuminates a girder steel 1 in the form of a ring. After photographing the steel 1, the sensor head 16 processes the image thereby to measure the central position of a bolt hole 2 and to obtain the pitch, position and direction of the hole. Moreover, the head 16 irradiates a slit beam, thereby measuring the length of the steel and distance between the hole and an end of the member. Accordingly, the warp and inclination of the member are measured by a four-point optical displacement sensor. A three-axis positioning arm 15 having a function to turn, oscillate and revolve supports the head 16, allowing the head 16 to be flexibly and speedily close to a measuring point. A scanning device 14 moves the arm 15 in three directions orthogonal to each other. Meanwhile a three-dimensional position measuring device 18 always tracks a tracing target 17 thereby to measure the distance to the target 17 by laser beams. In this manner, the three- dimensional position of the head 16 can be detected with high accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a dimension measuring device applied to factory inspections of structural members, and is also applicable to dimension inspections of other 8L vessels and the like.

BACKGROUND ART Generally, bridges are temporarily assembled as a product inspection method before being assembled at the construction site. Temporary assembly here refers to the work of assembling all or some of the materials and components at a factory, etc. immediately before transporting them to the construction site, and then checking to see if there are any problems with the construction. After inspection, it will be dismantled again and transported to the site.

However, while temporary assembly work is a reliable product inspection method,
There were problems that required time and money. For example, even a small bridge would take several days to complete, and in the case of a large bridge, the work would have to be done outdoors, making the work even more complicated and dangerous.

Therefore, instead of temporary assembly, which is an actual physical inspection, attempts have been made to develop an inspection method that checks whether there are any problems with the erection by optically measuring each member without contact. This method is called numerical temporary assembly.)
. An example will be explained with reference to FIG. 7.

As shown in the figure, in the steel girder 1 of a bridge, the bolt holes 2 that form the girder assembly part need to be strictly inspected for dimensional tolerances, arrangement, etc. as a result of product processing. Here, bolt hole 2
By arranging the spherical light source 3 which is a target for dimension measurement, placing the television camera 4a on the left and the television camera 4b on the right, and viewing the spherical light source 3 stereoscopically with a field of view 5 with no left-right shift, the spherical light source 3, i.e. The position of bolt hole 2 is measured three-dimensionally. This principle applies to monitor televisions 7a and 7a corresponding to television cameras 4a and 4b. When measured at the observation angle θ by 7b, the center of the screen is shared and images corresponding to the displacement are observed as shown in images 8 and 9, so the position of the spherical light source 3 can be determined by triangulation according to equation (4) below. Measurable.

However, (Xs. ``1e. Z*) is the three-dimensional coordinate value of point p, (X *. 'J t. Z x) is the camera-measured three-dimensional coordinate value of point p, and the sphere attached to the measurement target Triangulation is carried out using two CCD cameras of light source 3. M is a coordinate transformation matrix for correcting the rotational displacement of the object to be measured due to the movement of the cart, and (ΔX.ΔY, ΔZ) is the displacement of the object to be measured due to the movement of the cart. It is.

Since such calculations are performed in the image processing device 10,
Numerical output can be obtained online and temporary numerical assembly is possible, but since the field of view 5 of the TV cameras 4a and 4b is limited, in order to inspect the entire girder steel 1 of the bridge, It is necessary to load it onto the carrier vehicle 6 and move it.

As described above, numerical temporary assembly can be carried out to some extent using the conventional technology, but there are the following problems.

<1) Temporary assembly of components requires comprehensive component dimension data that combines not only hole positions, but also distances between holes, distances and directions between holes and the ends of components, and warpage and inclination of components. However, in the above-mentioned conventional technology, only the position of the hole can be determined, but other data such as the arrangement etc. can not be determined.

(2) It is necessary to install a ball light source at the part to be measured, which requires a large amount of setup time, which is no different from the usual temporary assembly man-hours.

(3) For example, rigid body movement is required to transport members such as girder steel using carts, but this is technically difficult and difficult to compensate for accuracy.

(4) When a ball light source is placed in a bolt hole, the installation accuracy tends to be ambiguous, leading to human error and resulting in a lack of reliability.

As described above, the above-mentioned conventional technology has many problems in practical use, and solutions to these problems have been desired.

<Problems to be solved by the invention> The present invention aims to solve the following problems.

■Dimensions of the parts required for numerical temporary assembly include hole positions,
To develop a multifunctional sensor capable of measuring hole pitch, distance between holes and ends, arrangement, warpage and inclination of members, etc. with high precision.

■ Developing a means to move the sensor close to the member and measure the dimensions of the required part using flexible and highly accurate positioning without blind spots.

■Developing a means of measuring a wide measurement range with high precision.

■Furthermore, after overcoming the above issues, apply it to numerical temporary assembly and improve its practicality.

Means for Solving the Problems〉 The structure of the present invention that solves the above objects includes an imaging device, a ring illumination, a slit light source, and a member that measure the hole position, hole pitch, distance and arrangement of the hole and the end of the member as part dimensions. Warp,
a multi-functional sensor head having a four-point optical displacement meter for measuring inclination; a three-axis positioning arm that supports the multi-functional sensor head and allows it to approach a measurement point by rotating, swinging, and turning functions; a scanning device that scans a 3-axis positioning arm in three mutually orthogonal directions; a tracking target provided on the multifunctional sensor head as a drive origin; The present invention is characterized by comprising a three-dimensional position measuring device that tracks a tracking target and measures the distance to the tracking target using a laser beam.

<Function> (1) The member to be measured is imaged by the imaging device, and is also illuminated in a ring shape by ring illumination to obtain uniform illuminance. The image obtained by the imaging device is subjected to image processing, only the hole is recognized, and the hole center position is measured from the center point of the hole.

■The pitch of the holes is determined based on the results of recognizing multiple holes, and by measuring the distance between their centers. At the same time, the placement and direction of the holes are also required.

(2) The distance between the hole and the end of the member is determined by measuring the length of the slit light emitted from the slit light source.

■The warpage and inclination of a component can be determined by measuring the distance to the component using a four-point optical displacement meter.

■The multifunctional sensor head is supported by a 3-axis positioning arm that has the functions of swivel, swing, and turn, allowing the multifunctional sensor head to be moved to the measurement point flexibly, with high precision, and at high speed. .

■Since the 3-axis positioning arms can be moved in mutually orthogonal directions by the scanning device, it is possible to measure dimensions over a wide range.

■Since the three-dimensional position measuring device constantly tracks the tracking target and measures the distance to the tracking target, the three-dimensional position of the multifunctional sensor head can be detected with high precision.

<Example> Hereinafter, the present invention will be described in detail based on an example shown in the drawings.

An embodiment of the present invention is shown in FIGS. 1 to 6.

As shown in the figure, bolt holes 2 are provided in the girder steel 1 of a bridge, which require measurement of member dimensions.

A rail 14b is laid on the floor along the girder steel 1 in the Y-axis direction in the figure, and a scanning device 14 is slidably installed on this rail 14b via a three-dimensional orthogonal coordinate type scanning mechanism 14a. ing. A highly accurate three-axis positioning arm 15 is attached to the scanning device l4 so as to be movable in the XY axis directions in the figure, and a multifunctional sensor head 16 is mounted on the tip of the arm 15. The high-precision 3-axis positioning arm 15 has three joints as shown in FIG. Owned) l7 is installed. The inclinometer 23 measures the inclination of two axes (YZ direction in FIG. 1), and measures the level of the drive origin in order to guarantee the independent high-precision positioning function of the high-precision 3-axis positioning arm l5. . The tracking target l7 is provided as a drive origin, and becomes a target tracked by the three-dimensional position measuring device l8 as the high-precision three-axis positioning arm 15 moves. As shown in FIG. 1, the three-dimensional position measuring device 18 is mounted on a high-precision positioning device 20 so as to be rotatable about two axes, the θ axis and the φ axis. Therefore, even if the scanning device 14 moves on the rail 14b, the position of the tracking target 17 can be accurately captured. , it becomes possible to move while measuring component dimensions.

In other words, the scanning device l1 has no error if the level is guaranteed.

The configuration of the tracking target l7, three-dimensional measuring device 18, etc. is shown in FIG. 3(a). As shown in the figure, the tracking target l7 is a coaxial combination of a corner cube 17a for the laser side length and a circular light source 17b, and
θ of the three-dimensional position measuring device l8 by turning and swinging φ
It has the function of tracking along the axis and φ axis. Therefore, even if the scanning device l4 moves, the tracking target l7
and the three-dimensional measuring device 18 can always face each other across the optical measurement axis l9.

Next, an automatic tracking and positioning method will be explained. When light is emitted from the circular light source 17b and observed as light source light 19a by the visual sensor 18f, a circular shape is obtained on the monitor television 25.

In this circular figure, it is assumed that the center of the tracking target 17 generally does not coincide with the optical axis center dxo, dy0 of the optical measurement axis l9, and the amount of deviation from them is dx, dy.

Then, the circular light source 17b is tracked by the visual sensor 187 so that the deviation Jt d x +dy becomes small, and θ
If control is performed so that = -θ' φ = -φ', automatic tracking positioning will be possible.

Distance D between the tracking target 17 and the three-dimensional measuring device l8
+s is measured as follows. That is, the semiconductor laser modulation optical system 18a has two types, for example, 670m++ and 830mn.
The beam splitter 18d modulates two types of semiconductor lasers having a wavelength of On the other hand, the optical sensor 18h measures the laser length measurement light 19b that has passed through the light receiving lens 18i and the mirror 18j to reach the corner cube 17a, thereby obtaining a measurement signal M.

As a result, the phase difference ΔP between the reference signal R and the measurement signal M is calculated, and the distance DI1 is determined as follows.

D13 = 1 work 1.''J1... (1) 2fn 360 However, C is the speed of light (3XIO''m), f is the modulation frequency, Δ
P is the measurement phase and n is the refractive index of the medium. Also, in the figure,
18e. 18f, 18j. 18k is a mirror having filter-like characteristics in consideration of the laser wavelength, etc.

In this way, the three-dimensional position measuring device 18 is characterized by not only being able to measure any length by applying variable modulation to the semiconductor laser, but also using two types of wavelengths. In other words, the refractive index of the optical measurement axis l9 changes depending on the measurement environment, specifically, changes in temperature, humidity, and atmospheric pressure, so the true distance D + s is obtained by compensating for the environment. It is necessary to ask for Therefore, the three-dimensional position measuring device l8 maintains accuracy by recalculating this using two types of wavelengths as follows.

In this way, the two-axis information of the θ axis and φ axis of the three-dimensional position measuring device l8, the tracking target l7, and the three-dimensional measuring device 11g
The true distance between D. . From this, the three-dimensional coordinates (xt, yt, ZT) of the tracking target 17 can be easily obtained. In other words, three-dimensional position measurement for dimension measurement can be performed with high precision as the scanning device l4 moves over a wide range.

Next, a method for measuring dimensions using the multifunctional sensor 16 will be explained with reference to FIG.

As shown in FIG. 4(a), the multifunctional sensor l6 includes an ultra-small television camera 26, a slit light source 27, and an optical displacement meter 2.
8. Equipped with ring lighting 29. Hole position measurement is
As shown in the same figure (bl), the field of view 3l of the ultra-compact television camera 26 is uniformly illuminated by the ring illumination 29, and the image within the field of view 31 is binarized by image processing to recognize the bolt hole 2 with graphical characteristics. In addition, the pitch between the holes and the distance between the member end 33 and the hole end are determined by applying the slit light 27a from the slit light source 27 to the field of view 3l and performing image processing using the light cutting method, as shown in FIG. Recognize and measure the warpage and inclination of other members by measuring the distance to the member 35 at optical displacement #28 arranged at four points as shown in Figure (d) to easily determine their three-dimensional arrangement. can be measured.

Such hole position measurement, large pitch, distance between the member end 33 and hole end, and other member warpage and inclination are applied in appropriate combinations so that member dimensions can be measured with high accuracy.

In addition, these scanning devices l4, high-precision 3-axis positioning arm l
5 and the multifunctional sensor head 16 are connected to the member dimension measuring device 12 via a control cable 21, and the three-dimensional positioning device 18 and the high precision positioning device 20 for the θ and φ axes are connected to the control cable 22. Via the member dimension measuring device 1
Connected to 2. The component dimension measuring device l2 connects to the numerical temporary assembly simulation system 11 via the communication line l3.
It is connected to the. In other words, the system block of the configuration of this embodiment is as shown in FIG.

In this embodiment having the above configuration, the operation when performing numerical temporary assembly will be explained with reference to the flowcharts in FIGS. 6(a) and 6(b).

First, as shown in FIG. 6(a), the members that will become the temporary assembly part,
For example, the numerical temporary assembly simulation system 11 selects bolt holes, etc., and communicates the selection to the member dimension measuring device 12 via the communication line 13. In the member dimension measuring device 12,
When a measurement point is designated, as shown in FIG. 6(b), the scanning device 14 is controlled to move in the XYZ-axis directions, and the high-precision 3-axis positioning arm 15 is controlled to move by functions such as rotation. and move the multifunctional sensor head 16 to the vicinity of the measurement point. The multifunctional sensor head 16 measures the dimensions of a member serving as a measurement point. For example, as described above, hole positions, hole arrangement, board warpage, inclination, etc. are measured. at the same time,
Rotate the three-dimensional position measuring device l8 around the θ and φ axes,
The tracking target 17 is automatically tracked and the tracking target 17 is automatically tracked. True distance DI between point 17 and three-dimensional measuring device I8
9. is calculated, and the three-dimensional coordinates (X
v, 3't. Find Zt). Such measurement results are
It is output to the numerical temporary assembly simulation system 11 via the communication line 13. Then, as shown in FIG. 6(b), numerical preliminary assembly simulation is performed based on these measurement results according to the following formula.

...(3) However, (X, Y, Z) are the three-dimensional coordinates of the measurement point, (ΔX,
Δy, Δ2) are the multifunctional sensor head measurement coordinates, and Δ
Is X and Δy the visual sensor 181? ΔZ is measured by the optical displacement meter 28. (xy, y■, z.t)
is the three-dimensional coordinate of the tracking target 17, (R x.
R v. Rz) is a coordinate rotation transformation matrix based on the measured value of the inclinometer 23, and (A1, A2, A!) is a transformation matrix representing the position and orientation of the multifunctional sensor head reference point as seen from the tracking target 17. This transformation matrix has the following relationship.

<Effects of the Invention> As specifically explained above based on the embodiments, the present invention has the following features: hole position, hole pitch, distance between holes and ends, arrangement, and member dimensions required for numerical temporary assembly. It is possible to realize a multi-functional sensor that can measure warpage, inclination, etc. with high precision, and by bringing this sensor close to the member, it is possible to measure the dimensions of the required part without blind spots with flexible and highly accurate positioning. A three-axis positioning arm could be realized as a means, and a scanning mechanism could be realized as a means capable of measuring a wide measurement range with high precision. Furthermore, if the present invention is applied to numerical temporary assembly, its practicality can be improved.

[Brief explanation of the drawing]

FIG. 1 is an overall perspective view showing an embodiment of the present invention, FIG. 2 is a configuration diagram of a high-precision three-axis positioning arm, FIG. 3(a) is a configuration diagram of a tracking target and a three-dimensional positioning device, and FIG. 3
Figure (b) is a graph showing the reference signal and measurement signal, Figure 4 shows the multifunctional sensor head, Figure (a) is its external perspective view, Figure (b) shows hole position measurement using ring illumination. An explanatory diagram, (C) is an explanatory diagram showing hole arrangement measurement using a slit light, and (d) is an explanatory diagram showing the warpage of a member using an optical displacement meter.
An explanatory diagram showing inclination measurement; FIG. 5 is an explanatory diagram of a system block according to an embodiment of the present invention; FIGS. 6(a) (b)
are a flowchart according to an embodiment of the present invention, and
FIG. 7 is an explanatory diagram showing conventional numerical temporary assembly. In the drawing, l is the girder steel, 2 is the bolt hole, 3 is the bulb light source, 4a, 4b are the TV cameras, 5 is the field of view of the TV camera, 6 is the transport vehicle, ? -a and 7b are monitor TVs, 8.9 is a TV camera image, 10 is an image processing device, 1l is a numerical temporary assembly simulation system, 12 is a component dimension measuring device, 13 is a communication line, 14 is a scanning device, 15 is a height 3-axis precision positioning arm, 16 is a multifunctional sensor head, 17 is a tracking target, 18 is a three-dimensional position measuring device, 19 is an optical measurement axis, 20 is a high-precision positioning device, 21 and 22 are control cables, 23 is a 6 is an ultra-small television camera, 7 is a slit light source, 8 is an optical displacement meter, and 9 is a ring illumination.

Claims (1)

[Claims] A multifunctional sensor head with an imaging device, ring illumination, slit light source, and a 4-point optical displacement meter that measures the warpage and inclination of the component, which measures the hole position, hole pitch, distance and arrangement between the hole and the end of the component as component dimensions. a 3-axis positioning arm that supports the multi-functional sensor head and causes it to approach a measurement point by rotating, swinging, and rotating functions; and a scanning device that scans the 3-axis positioning arm in three mutually orthogonal directions. , a tracking target provided as a drive origin on the multifunctional sensor head, and tracking the tracking target by following the movements of the three-axis positioning arm and the scanning device, and measuring the distance to the tracking target with a laser beam. 1. A dimension measuring device for a structural member, comprising: a three-dimensional position measuring device that measures using a three-dimensional position measuring device.