JPH11248432A - 3-dimension shape measuring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a 3-dimension shape measuring device wherein the 3-dimension shape of the entire region of an object which is to be measured can be certified even when the dimension of the object whose 3-dimension shape is measured is large and its entire region cannot be accommodated within a field of sight of an imaging means. SOLUTION: A CCD camera 17 as an imaging means for imaging a partial region of an object W which is to be measured, a movement means which moves the imaging means to an arbitrary position relative to the object W, a coordinate data translation part 36 which translates an image data of the partial region of the object W to a 3-dimension coordinate data of the object W, an NC device 21 which, as a control means, controls position of the movement means for sequentially moving the imaging means to the entire region where the object can be imaged, and a synthetic data synthesizing part 39 wherein the 3-dimension coordinate data of a plurality of regions for the object W are synthesized base on the imaging position information of each 3-dimension coordinate data for specifying 3-dimension shape of the entire object, are provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a three-dimensional shape measuring apparatus for converting a three-dimensional shape of an object to be measured into numerical data.

[0002]

2. Description of the Related Art For example, after a workpiece is machined by an NC machine tool, a three-dimensional shape is usually measured to check whether the workpiece is machined to a desired shape and machining accuracy. The three-dimensional shape of the workpiece is measured. A three-dimensional shape measuring device is used for measuring the three-dimensional shape of the workpiece. There are various types of three-dimensional shape measuring devices. For example, a light source for irradiating a workpiece with light, a CCD camera for capturing an image of the workpiece irradiated with light, and a CCD camera having an arbitrary position and posture. And an image processing apparatus for processing image data picked up by a CCD camera and converting the data into three-dimensional coordinate data of a workpiece.

[0003]

However, in the three-dimensional shape measuring apparatus having the above structure, the field of view of the CCD camera is limited to a certain range. For example, a workpiece having a large size that cannot be accommodated in the field of view of the CCD camera. In this case, there is a disadvantage that the three-dimensional shape of the entire workpiece cannot be specified.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned disadvantages, and has a large dimension of an object to be measured whose three-dimensional shape is to be measured. It is an object of the present invention to provide a three-dimensional shape measuring apparatus capable of specifying a three-dimensional shape of an entire region of the object to be measured even when the three-dimensional shape is out of the field of view.

[0005]

According to the present invention, there is provided an image pickup means for picking up an image of a partial area of an object to be measured, and a moving means for moving the image pickup means to any position with respect to the object to be measured. Means for converting image data of a partial area of the object to be measured into three-dimensional coordinate data of the object to be measured, and performing position control of the moving means, and Control means for sequentially moving the object to all the imageable areas, and combining three-dimensional coordinate data of a plurality of areas of the object to be measured based on the imaging position information of each of the three-dimensional coordinate data; Combining means for specifying a three-dimensional shape of the entire object.

In the present invention, the imaging means is moved by the moving means, so that the imaging means obtains imaging data of a plurality of areas of the measured object. The imaging data of each area of the object to be measured is converted into three-dimensional coordinate data by the conversion means. The synthesizing unit synthesizes the three-dimensional coordinate data based on the position information of the imaging unit that has acquired the three-dimensional coordinate data, thereby specifying the three-dimensional shape of the imageable area of the measured object.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram illustrating a configuration example of a three-dimensional shape measurement system according to an embodiment of the present invention. As shown in FIG. 1, the three-dimensional shape measuring system according to the present embodiment includes a three-dimensional measuring device 1, an NC device 21, and an image processing device 31.

The coordinate measuring machine 1 comprises a bed 3 and a bed 3
A table 5 on which an object to be measured W is mounted and guided so as to be movable in the X-axis direction, a gate-shaped fixed frame 7 provided across the bed 3 in the Y-axis direction, and a Z-axis direction The cross beam 9 held by the gate-shaped fixed frame 7 so as to be movable in the vertical direction, the saddle 11 held by the cross beam 9 so as to be movable in the Y axis direction, and the saddle 11 so as to be movable in the Z axis direction.
And the ram 13 held by the Further, a CCD (Charge Coupled Device) is provided at the lower end of the ram 13.
An imaging head 15 having a camera and a projector is provided.

The table 5 is driven in the X-axis direction by a servo motor and a feed mechanism (not shown). Thereby, the measured object W can be moved to any position in the X-axis direction. The saddle 11 is driven in the Y-axis direction by a servo motor and a feed mechanism (not shown). Thus, the imaging head 15 can be moved to any position in the Y-axis direction. The ram 13 is driven in the Z-axis direction by a servo motor and a feed mechanism (not shown). Thereby, the imaging head 15 can be moved to an arbitrary position in the Z-axis direction. Therefore, by controlling the position of the table 5, the saddle 11, and the ram 13,
The relative position between the measured object W and the imaging head 15 can be arbitrarily changed.

FIG. 2 shows a CC provided on the imaging head 15.
It is explanatory drawing which shows the positional relationship of a D camera, a projector, and a measured object. As shown in FIG. 2, the projector 16 emits light toward the measured object W. Also,
The CCD camera 17 is an imaging device using a charge-coupled device and having a viewing angle θ in a predetermined range. CCD camera 17
Receives the reflected light of the light raised toward the measured object W by the projector 16, and images the measured object W three-dimensionally in a moire manner. As shown in FIG. 2, at the viewing angle θ of the CCD camera 17, only a part of the area of the measured object W can be imaged.
While sequentially changing the relative position between the object to be measured W and the imaging head 15, image data of the entire area where the object to be measured W can be imaged is acquired.

FIG. 4 is a block diagram showing an example of the configuration of the NC unit 21. The NC device 21 controls the drive of each axis servomotor that drives the X axis to the Z axis of the coordinate measuring machine 1 by N.
This is performed in accordance with the measurement / imaging program input to the C device 21. As shown in FIG. 4, the NC device 21 includes a main control unit 22, each axis servo control unit 23, each axis servo driver 24, a program storage unit 26, and a position data output unit 27. .

The main controller 3 analyzes (decodes) an NC program programmed in a predetermined language for changing the relative position between the object to be measured W and the image pickup head 15 to process the trajectory data for each control axis. Has a function of generating control information such as a position command to be moved and outputting the control information to each axis servo control unit 23.

The program storage unit 27 stores the object to be measured W
An NC program in which data for changing the positions of the object W to be measured for measuring the three-dimensional shape and the imaging head 15 and the like are programmed in a predetermined language.

The servo control unit 23 includes a position loop, a speed loop, and a current loop. The position loop is
The above-mentioned table 5, saddle 11 and ram 13 are driven in proportion to the deviation from the position feedback signal from the rotational position detector 25a for detecting the rotational position of each axis servomotor 25 for driving the ram 13, and this is converted into the speed for the speed loop. Output as a command. The speed loop performs a proportional operation and an integral operation on a deviation between the speed command and a difference value (speed feedback signal) for each sampling time of the position feedback signal from the rotational position detector 25a to generate a torque command. Output to the current loop. For example, the current loop performs a proportional operation on a deviation between the output torque signal of each axis servo motor 25 converted from the drive current of each axis servo motor 25 and the torque command to generate a current command. And converts it into a predetermined electrical signal and outputs it.

Each axis servo driver 24 outputs a drive current obtained by amplifying a current command from each axis servo control unit 23 to each axis servo motor 25. Each axis servomotor 25 is driven according to the drive current, and the rotation position detector 25a of each axis servomotor 25 sends a detection pulse corresponding to the rotation amount of each axis servomotor 25 to each servo control unit 23. Output.

The position data output section 27 acquires a detection pulse corresponding to the rotation amount of each axis servo motor 25 through each axis servo driver 24 and the main control section 22, and outputs this to the image processing apparatus. That is, each axis servo motor 2 that drives the above-described table 5, saddle 11, and ram 13
The relative position information between the imaging head 15 and the object to be measured W can be obtained from the detection pulse of the rotation position detector 25a.

FIG. 3 is a configuration diagram showing an example of the configuration of the image processing device 31. In FIG. 3, the image processing device 31
Image data input unit 32, image data storage unit 33, position data input unit 34, position data storage unit 35, coordinate conversion unit 36, part data creation unit 37, part data storage unit 38, data synthesis And a part 39.

The image data input section 32 is a CCD camera 1
The captured image data of 7 is taken into the image processing device 31. The image data storage unit 33 stores and holds the image data captured by the image data input unit 32. That is, the image data storage unit 33 stores the imaging data of each area of the measured object W.

The position data input unit 34 fetches relative position information between the imaging head 15 and the object to be measured W output from the position data output unit 27 of the NC device 21 into the image processing device 31. The position data storage unit 35 stores the relative position information between the imaging head 15 and the object to be measured W which is captured through the position data input unit 34.

The coordinate conversion unit 36 includes an image data storage unit 33
Is converted into three-dimensional coordinate data of the measured object W based on the imaging data of the area of each part of the measured object W stored in the. The conversion from the imaging data to the three-dimensional coordinate data of the measured object W is performed by calculating the distance to the measured object W based on the imaging data for each pixel. For example, as shown in FIG. 5, the three-dimensional coordinates Pr (i) of each pixel of the imaging data 51 in a predetermined range are calculated.

A part data creating section 37 creates relative position information and relative position and orientation information between the object to be measured W and the CCD camera 17 at each imaging position stored in the position data storage section 35 by means of a coordinate conversion section 36. The data added to the obtained three-dimensional coordinate data of each area of the measured object W is created. That is, by adding information indicating the relative position and orientation of the measured object W and the CCD camera 17 to the three-dimensional coordinate data of each region of the measured object W, the three-dimensional coordinate data of each region is added. A correlation can be provided between them. Specifically, as shown in FIG. 5, a normal vector n indicating the direction of the plane of the imaging data 51 in a predetermined range.
r is obtained from relative position information between the object to be measured W and the CCD camera 17 and is added to the three-dimensional coordinate data of each area. The normal vector nr is a vector (nx, ny, nz) in the X-axis, Y-axis, and Z-axis directions indicating the relative attitude of the object W to be measured and the CCD camera 17; It consists of information on the distance d from the camera 17. The part data storage unit 38 stores each part data created by the part data creation unit 37.

The data synthesizing section 39 synthesizes each part data stored in the part data storage section 38 and specifies three-dimensional shape data of the whole area of the object W to be measured which can be imaged. That is, each part data created by the part data creation unit 37 has three-dimensional coordinate data of each area of the measured object W and the relative position and orientation of the measured object W and the CCD camera 17. By connecting these pieces of part data, it is possible to specify the three-dimensional shape data of the entire imageable area of the measured object W.

Next, an example of a measuring procedure by the three-dimensional shape measuring system according to the present embodiment will be described. First,
An NC program for specifying a movement locus for sequentially moving the imaging head 15 with respect to the measured object W is input to the NC device 21. For example, by repeatedly moving the imaging head 15 relative to the measured object W by a predetermined step amount,
An NC program is created so that the field of view of the CCD camera 17 covers the entire range in which the object to be measured W can be imaged.

Next, the imaging head 1 is moved by a predetermined step amount.
5 relative to the object W to be measured, CC
The object to be measured W is imaged by the D camera 17. As a result, the image data and the position data are stored at predetermined addresses of the image data storage unit 33 and the position data storage unit 35 of the image processing device 31, respectively.

When the imaging of the whole range of the object W to be imaged is completed, the three-dimensional shape data of the entire object W to be measured is specified in the image processing device 31.

As described above, according to the present embodiment, each area of the measured object W is imaged by the CCD camera 17, and each imaged data is converted into three-dimensional coordinate data of each area of the measured object W. I do. In the three-dimensional coordinate data of each area,
Each piece of information indicating the relative position and orientation between the measured object W and the CCD camera 17 is added, and the three-dimensional coordinate data of each area of the measured object W and the information between the measured object W and the CCD camera 17 are added. Create data having relative positions and postures. As a result, it is possible to specify the three-dimensional shape data of the entire imageable area of the measurement target object W.
In addition, since the series of processes described above is performed in the image processing device 31, it is possible to quickly and easily specify the entire three-dimensional shape data of the measured object W.

[0027]

According to the present invention, even when the size of the object to be measured whose three-dimensional shape is to be measured is large and the entire area of the object to be measured does not fit in the field of view of the imaging means, the object to be measured can be used. It is possible to easily and quickly obtain three-dimensional shape data of the entire region of the measurement object.

[Brief description of the drawings]

FIG. 1 is a configuration diagram illustrating a configuration example of a three-dimensional shape measurement system according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a positional relationship between a CCD camera and a projector provided on an imaging head 15 and an object to be measured.

FIG. 3 is a configuration diagram illustrating a configuration example of an image processing apparatus 31.

FIG. 4 is a configuration diagram illustrating a configuration example of an NC device 21.

FIG. 5 is a diagram for explaining the contents of data created by a part data creation unit.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Coordinate measuring machine 16 ... Projector 17 ... CCD camera 21 ... NC apparatus 31 ... Image processing apparatus 32 ... Image data input part 33 ... Image data storage part 34 ... Position data input part 35 ... Position data storage part 36 ... Coordinate conversion Part 37 ... part data creation part 38 ... part data storage part 39 ... data synthesis part

Claims (1)

[Claims] An imaging unit configured to image a partial region of the measured object; a moving unit configured to move the imaging unit to an arbitrary position with respect to the measured object; and a part of the measured object. Conversion means for converting the imaging data of the area to three-dimensional coordinate data of the object to be measured, and performing position control of the moving means, and sequentially moving the imaging means to the entire area where the object to be measured can be imaged. Control means for causing, the three-dimensional coordinate data of a plurality of regions of the object to be measured,
Combining based on the imaging position information of each of the three-dimensional coordinate data,
A synthesizing means for specifying a three-dimensional shape of the whole object to be measured.