JPS63289406A - Three-dimensional configuration measuring instrument - Google Patents

Abstract

PURPOSE:To surely project and photograph a stereoscopic image in a short time by forming a frame capable of accommodating an object, fixedly arranging a number of the pairs of cameras and projectors and photographing the object at a plurality of angles by sequentially driving those pairs. CONSTITUTION:A slit image 14 obtained by irradiating a solid object 13 by light from the light source 10 of a projector via a multi-slit plate 11 is read by a camera as a graduational image plane 16 in a different position. From data into which a read result is binary-coded, the data of the three-dimensional coordinates of a stereoscopic image are obtained by a host computer. At this time, a plurality of the pairs of projectors 104a-104d having the slit plate 11 in their fronts and cameras 103a-103d are fixed onto a frame 102. Those are sequentially driven and the object 13 is photographed at a plurality of angles. Thus, the cameras 103a-103d are changed over in a short time to remove the effect of the light from the other projectors and the data of the three- dimensional coordinates of the stereoscopic image can be obtained.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a three-dimensional shape measuring device, and more particularly, to a three-dimensional shape measuring device that automatically produces a three-dimensional image similar to an object using a multi-axis milling machine or the like. The present invention relates to a three-dimensional shape measuring device used in the device.

[Prior Art] As an apparatus for reading three-dimensional data of an object and recognizing a three-dimensional image based on the shape measurement data, a device such as that described in Japanese Patent Application Laid-Open No. 81-241812 is known. There is.

FIG. 8 explains the principle of three-dimensional shape measurement. In the figure, reference numeral 10 indicates a light source, such as an incandescent lamp or a strobe light.

A multi-slit plate 11 is arranged in front of this light source. , this multi-slit plate 11 is not rotated and scanned and is fixed.

A projector lens 12 is arranged in front of the multi-slit plate 11, and a striped slit image 14 is formed on the object 13 via the projector lens 12.

This slit image 14 is formed as a slit image 14a bent according to the unevenness of the object 13 on an imaging surface 16 which is a film through a camera lens 15.

The image is inverted by using the projector lens 12 and the camera lens 15, but inversion using the projector lens does not require processing because the slit is vertically and horizontally symmetrical, and inversion using the camera lens is processed by transposing the film.

A bent slit image is thus obtained, and the position of each point on the slit image is calculated as three-dimensional coordinate values using the principle of triangulation to obtain data on the three-dimensional shape of the object.

[Problems to be solved by the invention] When actually performing three-dimensional shape measurement, the object is photographed by changing its position several times using the method described above, but each time the camera and Adjusting the projector position is not only cumbersome but also produces inaccurate results.

For example, if the object is a human being, the face, hair, and clothes have different surface conditions and cannot be processed with one type of slit.For example, if the object is a human face, the surface is continuous and smooth. Since the main curves are relatively fine slits with a pitch of 0.3 mm, in the case of clothes, the surface is continuous and the main curves are smooth, but there are steps at the collar, overlapping areas, and around the necktie. Because of this, slits with a pitch of 0.5 inch are chosen instead of fine slits like those used for faces.In the case of hair, the surface is discontinuous and there are many breaks, so fine slits cannot be used. 7m
It is necessary to change the slit depending on the position the camera is aiming at, such as using a slit with a pitch of m.

It is also necessary to accurately match data on film taken with different cameras.

Under such various conditions, it is considered advantageous to arrange a large number of cameras and projectors in a fixed manner in a space to take pictures from multiple angles.

The present invention was developed in view of the above-mentioned circumstances, and uses a device that photographs an object from multiple angles using a large number of cameras and projectors fixedly arranged in space to obtain three-dimensional coordinate data of a three-dimensional image. In this case, the cameras must be controlled to release their shutters in sequence to eliminate the influence of projector light from other sets.
In addition, the camera must be switched in the shortest possible time to avoid movement of the subject as much as possible.

[Means for Solving the Problems] In order to solve the above problems, according to the present invention, a frame capable of accommodating an object is formed, a large number of sets of cameras and projectors are fixedly arranged, and the cameras and projectors are fixedly arranged. A configuration is adopted in which the set is sequentially driven to photograph an object from multiple angles.

[Example] The present invention will be described in detail below using examples shown in the drawings.

FIG. 1 shows, for example, four cameras 103a to 103d and four projectors 104a to 104d each having a slit, which are provided on the same plane to photograph an object 13 to be photographed from the surrounding area according to the apparatus of the present invention. The arrangement is shown in which each camera and projector are fixed to a mole rail 105 in a pair at a predetermined distance and at a predetermined angle from each other, and are arranged in a frame 102 indicated by a dotted line.

Note that each camera and projector must be arranged so that their respective optical axes are on the same plane and have a point of intersection at the center P of the object 13.

What is shown in FIG. 2 is a camera 103a and a projector 10.
4a is an exploded perspective view showing the positional relationship between the mole rail 105 and the frame 102 to which both are attached.

A camera stand 107 is mounted on a mounting plate 106 having a hole 106a fixed to one end of the mole rail 105, with an internally threaded sleeve 107a protruding from its lower surface fitted into the hole 106a. The camera 103a is mounted on one end of the mole rail 105 by screwing bolts 108 and 109 into holes formed in the camera from the bottom surface of the mounting plate 106 and the outside surface of the camera stand 107, respectively. It will be done. In this case, by operating the bolt 108, the camera stand 107 and the camera 103 placed on it can be
a can be rotated horizontally around the bolt 108.

Similarly, a mounting plate 110 having a hole 110a is fixed to the other end of the mole rail 105, and a projector stand 111 is mounted on the mounting plate 110, with an internally threaded sleeve 1lla protruding from the lower surface of the mounting plate 110 placed in the hole 110a. The projector 104a is mounted on the projector stand 111, and the bolt 112 is inserted from below the mounting plate 110 through the sleeve IL1a into a screw hole (not shown) formed in the projector. By aligning the projector 104a with the mole rail 105
is fixed to the other end. In this case as well, by operating the bolt 112, the projector stand 111 and the projector 104a placed thereon can be rotated horizontally around the pole 112.

Note that the projector 104a, the projector stand 111, and the mounting plate 110 are firmly fixed to each other by holes 113 provided therein.

Legs 114.1 are provided on the lower surface near both ends of the mole rail 105.
14 is provided in a protruding manner, and this leg is, for example, designated as a whole by reference numeral 1.
Frame 102t7) Arm 10 via a mounting member indicated by 15
2a and 102a, and are fitted with bolts 117, 117 and nuts 1, respectively.
18,118.

In this case as well, for example, by forming a large number of holes for fixing the mounting member 115 to the arm 102a of the frame 102, or by forming continuous grooves, the mole rail 1
05 and the frame 102 can be changed.

What is shown in FIG. 3 is a synchronous circuit for sequentially driving seven cameras 3a to 3g configured as shown in FIGS. 1 and 2.

In the figure, 40 is a shift register, and an oscillation circuit 41
from each output Pi-P7 via a tristed TI-T7 to a camera 3 as shown in FIG.
Periodic signals S1 to S7 are generated to drive the shutters a to 3g and the projector. The camera 3a obtains a shutter ON signal M1 in synchronization with the synchronization signal 31, and generates a counter lamp lighting signal M2. Subsequently, the strobe light is turned on as shown by the signal M3, and then the film is automatically wound by the autowinder signal M4. Periodic signals S2 to S are also applied to cameras 3b to 3g in the same manner.
Photographing is performed sequentially in synchronization with the falling edge of 7. Note that the projector may be operated in synchronization with each of the synchronization signals S1 to S7, or after a predetermined time delay.

Next, the operation of the three-dimensional measuring device using the device of the present invention configured as described above will be explained.

First, the measurement of the three-dimensional shape of the object 13 is calculated as shown in FIG.

FIG. 5 shows the geometric positional relationship when the measurement system is cut along a plane that includes the central axis of the camera lens and passes through the center of the projector lens.

In FIG. 5, each symbol has the following meaning.

P One point on the surface of the object to be measured Center of the PC camera lens Pa Center of the imaging surface (film) xn X coordinate yn indicating the position of point P on the imaging surface
Y coordinate indicating the position of point P on the imaging plane Distance L from one center of the camera lens to the imaging plane Projected point and point P when the center of rotational scanning is projected onto the camera lens central axis
Distance D between the center of rotational scanning and the central axis of the camera lens Yn Angle of the projected light Coordinates of point P on the object 13 (Xn, Yn.

Zn) is obtained as follows.

D+-Xn Zn=Xntanyn In addition, D, L, ff1. γn is determined by another method.

Furthermore, (x n + y n ) is obtained for each pixel obtained by digitizing an image using a CCD camera.

FIG. 6 shows a system for obtaining three-dimensional shape data of an object using the measurement system as described above.

In FIG. 6, reference numeral 20 indicates an imaging system, reference numeral 21 indicates a digitizing system, and reference numeral 22 indicates a data processing system.

The imaging system 20 includes a projector 24 equipped with the aforementioned projector lens 12 and a camera 25, both of which are mounted on the same pedestal 26.

The projector 24 is fixed, and the camera 25 is provided so that its three-dimensional position can be adjusted.

A plurality of pairs of such projectors and cameras are provided as described in FIGS. 1 to 4. Projector 24
The striped pattern of light irradiated from the multi-slit plate 11 is photographed by the camera 25, and the negative film 25 is photographed by the camera 25.
a is sent to the digitizing system 21 and photographed by the COD camera 27. As described above, a plurality of projector and camera sets are sequentially driven to perform three-dimensional photography from a plurality of directions.

The COD camera 27 is an image reading camera that captures the image on the negative film 25a as a grayscale image, and is controlled by the camera control unit 28.

The read image is processed by the personal computer 29 as black and white binary data.

Incidentally, reference numeral 30 denotes an adjustment oscilloscope, which serves to detect whether or not the image read by the COD camera 27 is in focus based on a waveform, and to perform adjustment.

Data from the personal computer 29 is connected to a host computer 31 forming the data processing system 22 via a line.

Reference numeral 32 indicates a graphic display.

What is shown in FIG. 6 mentioned above is the hardware configuration of the entire system.

By the way, the configuration of the software is as shown in FIG.

That is, the image read by the COD camera 27 is read as a light section image in step S1, and the image is stocked as an image file in step S2.

This image file is used for statistical processing and display of the original image in step S3, and is output as is on the CRT screen in step S4 in order to confirm the read original image. - On the other hand, edge processing is performed based on the image file in step S5 to detect edges of the image and striped patterns of slits, and an edge file is obtained in step S6.

Then, based on this edge file, thinning processing of the striped pattern of the slit is performed in step S7, and a thinning file is created in step S8.

Subsequently, based on this thinned file, tracking is performed in step S9 to trace and recognize the grid lines, and a tracking file is obtained in step SIO.

Then step Sll based on the tracking file
In step S12, three-dimensional coordinate values at each selected point are calculated, and at this time, the results of calibration, which is a process of calibrating the dimensions of the optical system in a separate step S12, are referred to. A coordinate value file is obtained in step S13. A detailed explanation of each step up to this point is provided by an example.

For example, this method is disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 81-241812.

Since the origin of the coordinate values stopped here is different for each set of camera and projector, mapping is performed in step S14 to set the origin of the seven sets to - (referred to as a unified coordinate system).

Specifically, the origin of each set is placed at the virtual light source position of each projector, and the origin of the unified coordinate system is placed at the center of the object.

Then, in step S15, the obtained unified coordinate values are converted into cylindrical coordinates, and in step 516, a cutter path for the NC machine is generated, and NC processing is performed.

In addition, when shooting with multiple cameras, you can project a reference mark during shooting, take a picture, and use this reference mark to recognize the same thin line with different cameras. Of course, it becomes easier to continuously grasp the slit image or striped pattern.

In addition, in the above example, the obtained data is output to the NC device and a multi-axis cutter is used to engrave a three-dimensional image of the object, but the data is sent to the wire frame via the display device. It can also be output as an image.

[Effects of the Invention] As is clear from the above description, according to the present invention, a three-dimensional image is continuously irradiated with multi-slit light over the entire surface,
A slit image on the object is photographed at a position different from the light source, the striped pattern created by the slit light is read as a shading image, 3D position information at each point is determined by triangulation, and 3D coordinate data of the 3D image is obtained. In order to obtain this, it becomes possible to reliably project and photograph a three-dimensional image in a short time, and there is an advantage that accurate three-dimensional shape data can be easily obtained.

[Brief explanation of drawings]

Figure 1 is a layout diagram showing the general arrangement of the camera and projector of the device of the present invention, Figure 2 is an exploded perspective view showing how to install a pair of cameras and projectors, and Figure 3 is an exploded perspective view showing how to install the camera and projector. 4 is a signal waveform diagram explaining the operation, FIG. 5 is an explanatory diagram showing the method of obtaining measured values, and FIG. 6 is an explanatory diagram showing the schematic configuration of the hardware system. FIG. 7 is an explanatory diagram showing the schematic configuration of the software system, and FIG. 8 is an explanatory diagram showing the measurement principle. 10... Light source 11... Multi-slit plate 1
2... Projector lens 13... Target object 14... Slit image 15.
...Camera lens 16...Imaging surface 20...Imaging system 21...Digitizing system 22...Data processing system 27...CCD camera 29...Personal computer 31...Host computer

Claims (1)

[Claims] It is equipped with an imaging system that takes images of a three-dimensional object, a digitizing system that binarizes the obtained image, and a data processing system that processes the obtained digital data. Slit light is irradiated, a slit image is taken on the object at a different position from the light source, the striped pattern is read as a shading image, the three-dimensional coordinate position of each point is determined by triangulation, and the three-dimensional image is In a three-dimensional shape measuring device that obtains data on three-dimensional coordinates, a plurality of pairs of projectors and cameras each having a slit on the front facing a three-dimensional object are fixed, and the projectors and cameras are sequentially driven to measure a plurality of objects. A three-dimensional shape measuring device characterized by photographing from an angle of.