JPH0814876A - System for automatically measuring dimensions of workpiece - Google Patents

Abstract

PURPOSE:To reduce the number of part programs previously prepared, by replacing a necessary numerical value part with variables in a part program stored to be stored in memory. CONSTITUTION:Image data of a workpiece picked up by CCD cameras 8, 9 are delivered to an image processing device 51 which processes the image data so as to deliver preliminary data composed of a workpiece position, a workpiece pattern and main dimensions of the workpiece. A three-dimensional unit data processing device 52 selects a part program for regulating a procedure for three-dimensional measurements in accordance with the preliminary data, and gives necessary variable to this part program so as to drive a controller 53 which in turn drives a stage moving mechanism 5 and a three-dimensional measuring unit 3. That is, during the execution of the part program, a necessary numerical value part in the part program is replaced with variable. Accordingly, one and the same part program can be used for workpieces having a pattern of the same kind even though the positions and dimensions of the workpieces are different from one another.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a work size automatic measuring system suitable for automatically measuring the sizes of works of various shapes and sizes.

[0002]

2. Description of the Related Art A system for automatically measuring various works having different shapes conveyed through a conveying line has been conventionally known (for example, Japanese Patent Laid-Open No. 60-35210). In this type of system, a work is imaged by an imaging device arranged upstream of the line, the shape of the work is discriminated from the imaging result, and the measuring robot arranged downstream of the line is operated by a program corresponding to the discriminated shape. I am trying.

When the dimension of a workpiece is measured by a coordinate measuring machine like this system, the probe used in the coordinate measuring machine and the moving path of the probe are given by a part program for controlling the coordinate measuring machine. To be Therefore,
Even if the workpieces have the same shape, if the position where they are placed and the dimension values such as inner diameter, outer diameter, and height differ, part programs corresponding to each position and dimension value are created and prepared. I have to keep it.

[0004]

As described above, in the conventional measuring system, since only the part program in which the measuring procedure is described is prepared in advance, it is possible to measure only the work whose approximate dimension value is known. . Further, as the number of types of workpieces to be measured increases, the number of part programs prepared in advance also increases, resulting in an increase in the amount of information to be stored.

The present invention has been made in order to solve such a problem, and it is possible to measure a workpiece whose approximate dimension value is unknown and reduce the number of part programs prepared in advance. An object is to provide a work dimension automatic measuring system capable of performing the work.

[0006]

An automatic workpiece dimension measuring system according to the present invention is based on external information fetching means for fetching various kinds of information regarding a workpiece to be measured as external information, and external information fetched by this means. Workpiece including control means for determining the movement path of the probe of the coordinate measuring machine with respect to the workpiece and controlling the coordinate measuring machine, and a coordinate measuring machine controlled by the control means to measure the dimensions of the workpiece In the automatic dimension measurement system, the control means stores a part program that is created for each pattern type of the work and has a necessary numerical part replaced with a variable, and a part program storage based on the external information. Means for selecting one part program corresponding to the work from the means, and the external information A variable holding means for holding as a numerical value corresponding to a variable, and a part program executing means for executing the selected part program while appropriately referring to the numerical value corresponding to the variable held by the variable holding means. It is characterized by being.

[0007]

According to the present invention, the necessary numerical part in the stored part program is replaced with a variable, and
Information such as the work position and dimension values fetched as external information is retained as numerical values corresponding to the above variables, and when the part program is executed, the variable part of the part program is replaced with numerical values corresponding to the variables. And the part program is executed. Therefore, as long as the workpieces have the same pattern, the same part program can be used even if the workpieces have different positions or dimension values, and the number of stored part programs can be significantly reduced. Even for workpieces whose approximate dimension values are unknown, external information can be used to perform measurement including the operation of selecting the probe to be used.

Incidentally, after the position information of the work is obtained from the measured value in the course of measurement by the coordinate measuring machine, the position information of the work held in the variable holding means is obtained from the newly obtained work. If the position information is replaced, the reliability of the work position information is improved, so that the efficiency of the subsequent measurement can be improved by making the probe path more severe with respect to the work.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A workpiece dimension automatic measuring system according to an embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a perspective view showing a schematic configuration of this system. On the known special pneumatic type vibration isolator 1, a special frame 2 for the vibration isolator is placed, and on one side of the special frame 2 there is a coordinate measuring machine 3 and on the other side. The first illuminating device 4 is installed in each. CMM 3
Is a base 11 and a bridge-shaped arm support 13 that moves in the Y-axis direction along Y-axis guides 12 at both ends of the base 11 and connects both ends of the base 11.
Along the X-axis guide 14 of this arm support 13
The Z-axis guide 15 that moves in the axial direction and the Z-axis guide 1
5, an arm 16 that moves in the Z-axis direction along with 5, and a measurement touch signal probe 17 supported by the arm 16 are configured. Further, the coordinate measuring machine 3 includes a probe automatic exchange device 1 for probe exchange.
8 are provided.

A measuring area of the coordinate measuring machine is formed above the surface plate 11 of the coordinate measuring machine 3, and an imaging area is formed above the first illuminating device 4. A stage drive mechanism 5 is installed so as to connect these two regions. The stage drive mechanism 5 includes two parallel rails 21 that connect the surface plate 11 of the coordinate measuring machine 3 and the first lighting device 4, and a U-shaped slide table that is guided and moved by the parallel rails 21. 22 and a motor 23 for driving the slide table 22 and a screw-shaped drive shaft 24. The pallet 6 is mounted on the slide table 22. The pallet 6 constitutes a stage on which the work 7 is placed, and is composed of a transparent glass plate 31 and a frame body 32 attached to the peripheral edge of the glass plate 31. Positioning holes 33 are formed in the frame body 32, and the pallets 6 are positioned on the slide table 22 by fitting the hole 33 and the positioning bosses 34 provided on the slide table 22.

CCD cameras 8 and 9 for picking up an image of the work 7 are provided above and sideways of the work 7 arranged on the pallet 6.
Are arranged respectively. A second illumination device 10 is arranged on the opposite side of the work 7 from the CCD camera 9. The lighting devices 4 and 10 each include a case 41 in which a light source (not shown) is housed, and a semitransparent plate 42 that seals the case 41 and uniformizes the light from the light source.

FIG. 2 is a block diagram showing a signal / information processing system of this system. The image information picked up by the CCD cameras 8 and 9 is supplied to the image processing device 51, where preliminary information including a work position, a work pattern, and a work main dimension is obtained by image recognition processing. The coordinate measuring machine data processing device 52 selects a part program that defines the procedure of the three-dimensional measurement from the preliminary information, gives necessary variables to this part program, and supplies it to the controller 53.
Drive. The controller 53 uses the stage drive mechanism 5
And driving the coordinate measuring machine 3.

Next, the operation of the present system thus constructed will be described. FIG. 3 is a flowchart showing the measurement procedure of this system. In the measurement start state, pallet 6
Are arranged in an imaging area where the CCDs 8 and 9 can image. In this state, when the work 7 is carried onto the pallet 6 by a conveying means such as a human or a robot (S1), C
The work 7 is imaged by the CD cameras 8 and 9 (S
2). At this time, the illumination light from the first illuminating device 4 illuminates the work 7 from below through the parallel rails 21, the hollow portion of the slide table 22 and the glass plate 31 of the pallet 6. Since the CCD camera 8 images the work 7 from above on the side opposite to the illumination device 4, the work 7 becomes backlit and the contrast between the work and the background is reduced as shown in FIG. 4A. Enhanced and clear image information is obtained. Similarly, the image information of the side surface of the work 7 obtained by the CCD camera 9 which receives the illumination light from the second illuminating device 10 shows that the contrast between the work portion and the background is as shown in FIG. 4B. The image information is emphasized and clear.

When the image information is supplied to the image processing device 51, the image processing device 51 calculates preliminary information from the supplied image information (S3). That is, as shown in FIG. 5, the image information is binarized by the binarization unit 61, and then the edge portion of the binary image is extracted by the contour extraction unit 62. continue,
In order to improve the processing efficiency of pattern matching, the characteristic extraction unit 63 extracts a characteristic portion from the contour information, and the characteristic portion and some basic patterns stored in the basic pattern storage unit 64 are collated by the collation unit 65. It As a result, the position calculating unit 66 and the main dimension calculating unit 67 calculate the main dimensions such as the position and inner diameter, outer shape, height, and width of the work from the characteristic portions of the image based on the obtained work pattern. Preliminary information including the obtained work pattern, work position, and work main dimension is transferred to the coordinate measuring machine data processing device 52 (S4).

In the coordinate measuring machine data processing device 52, first, as shown in FIG.
Selects one of the part programs stored in the pattern-based part program storage unit 72 based on the work pattern information provided from the image processing apparatus 51 (S5). Next, the work position in the image processing coordinate system obtained by the image processing device 51 is converted into the work position in the coordinate measuring machine coordinate system by the coordinate system correction unit 73 (S
6) The work position after conversion and the work main dimension given from the image processing device 51 are stored in the variable register 74 (S7). Then, the stage drive mechanism 5 operates under the control of the controller 53, the slide table 22 is moved from the imaging region to the measurement region by a predetermined movement amount, and the work 7 is conveyed to the measurement region ( S8).

When the movement of the work 7 is completed, the part program executing section 75 is activated and the selected part program is executed. In the part program, the amount of movement of the probe, information specifying the selected probe, and the like are given as variables, and it is possible to flexibly deal with works of various sizes. 7 and 8 are diagrams showing examples of part programs. Here, V1, V2, V3, ...
U9, U10, L9 and the like are variables, and the numerical values corresponding to them are given from the image processing device 51 or obtained by an operation in the part program, and are stored in the variable register 7
Stored in 4. This example is an example of measuring the inner diameter and outer diameter of a cylinder. For example, V1 is the depth of the cylinder, V2 is the number of measurement points, and V3.
Is the diameter, V20 is the number of cross sections to be measured, and U9 is the probe type.

The part program execution section 75 refers to the contents of the variable register 74 at any time during the execution of the part program, supplies the probe movement command and the necessary movement amount to the controller 53, and supplies the coordinate measuring machine 3 with the command. Touch of
The signal probe 17 is moved according to the part program. Thereby, automatic measurement is executed (S
9). Further, the part program execution unit 75 obtains the position of the work from the actual three-dimensional measurement value obtained in the process of this measurement, and replaces the work position given in advance with the work position obtained from the actual measurement value. As a result, the subsequent measurement is performed with the newly obtained accurate work position as a reference.

When the measurement is completed, the measurement data is output to an external device (S10), the stage drive mechanism 5 is activated,
The work 7 is moved from the measurement area to the imaging area (S1
1). The work 7 for which the measurement has been completed is carried out by a carrying means such as a human or a robot (S12).

According to this system, a plurality of works having different dimensions can be measured by the same part program if the shapes of the works are the same. Therefore, the number of part programs to be prepared depends on the work pattern. Only the type (for example, for cylinder, for cylinder, for cylinder with a collar, etc.) is sufficient, and the capacity of the part program storage unit 72 can be reduced. Further, it is possible to measure a workpiece having an unknown size based on the information from the image processing device 51.

In the above embodiment, it is assumed that the relationship between the positions of the CCD cameras 8 and 9 and the coordinate measuring machine 3 is unchanged, but the positions of the CCD cameras 8 and 9 themselves change. In the case of occurrence of, it becomes impossible to correctly determine the relationship between the coordinate system in the image information and the coordinate system of the three-dimensional measurement area. Therefore, for example, as shown in FIG. 9, a reference mark member 35 is provided on the frame body 32 of the pallet 6, and the position of the work 7 with the position of the reference mark member 35 as a reference is determined as the work position, whereby the image pickup means is obtained. It is possible to accurately obtain the work position regardless of the position variation of.

In order to calculate the three-dimensional position and posture of the work 7, the reference mark member 35 needs to be arranged at at least two positions which do not overlap in the XYZ axis directions. In this embodiment, the reference mark member 3 is provided at a diagonal position of the frame 32.
5 is provided. In addition, the reference mark member 35
The shape is preferably such that the pattern can be easily recognized and the position can be easily grasped accurately.
In this embodiment, since the reference sphere is formed at the tip of the reference mark member 35, there is an advantage that the pattern recognition is easy and the center position thereof is easy to be obtained. Since it is known in advance that the reference sphere is arranged at a predetermined position in both the imaging area and the measurement area, if the coordinate measuring machine 3 side also measures the position of the reference sphere. ,
The accuracy of coordinate conversion between both areas can be further improved.

Further, in the above embodiment, the information such as the shape, the position and the dimension recognized from the image information is used as the external information to be given to the coordinate measuring machine. Information or the like manually input may be given to the coordinate measuring machine as external information.

[0023]

As described above, according to the present invention, necessary numerical values in the stored part program are replaced with variables, and information such as the position and dimension value of the workpiece given from the outside is stored. The numerical value corresponding to the variable is held, and when the part program is executed, the variable part of the part program is replaced with the numerical value corresponding to the variable to execute the part program.
With the same kind of work, the same part program can be used even if the work position and dimension values are different, and the number of part programs to be stored can be greatly reduced and It is possible to measure a workpiece whose dimension value is unknown using external information.

[Brief description of drawings]

FIG. 1 is a perspective view of a workpiece dimension automatic measuring system according to an embodiment of the present invention.

FIG. 2 is a block diagram of a signal / information processing system of the system.

FIG. 3 is a flowchart showing a measurement procedure of the system.

FIG. 4 is a diagram showing an example of image information obtained by the system.

FIG. 5 is a functional block diagram showing a configuration of an image processing device in the system.

FIG. 6 is a functional block diagram showing a configuration of a coordinate measuring machine data processing device in the same system.

FIG. 7 is a diagram showing an example of a part program.

FIG. 8 is a diagram showing a continuation part of the part program shown in FIG. 7;

FIG. 9 is a perspective view showing another configuration example of a pallet in the same system.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Vibration isolation device, 2 ... Special mount for vibration isolation equipment, 3 ... Three-dimensional measuring machine, 4 ... First illumination device, 5 ... Stage drive mechanism, 6
… Palette, 7… Work, 8, 9… CCD camera, 10
… Second lighting device.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Shinji Takahashi 1-20-1 Sakado, Takatsu-ku, Kawasaki-shi, Kanagawa Mitutoyo Co., Ltd. (72) Inventor Naoya Kikuchi 1-20-1, Sakado, Takatsu-ku, Kawasaki-shi, Kanagawa Issue Mitutoyo Co., Ltd.

Claims (3)

[Claims] 1. An external information fetching means for fetching various kinds of information regarding a work to be measured as external information, and a movement path of a probe of a coordinate measuring machine with respect to the work is determined based on the external information fetched by this means. In a work dimension automatic measuring system including a control means for controlling a coordinate measuring machine and a coordinate measuring machine controlled by the control means to measure the dimension of the workpiece, the control means is a pattern of the workpiece. Part program storage means for storing a part program created for each type and having necessary numeric parts replaced by variables, and means for selecting one part program corresponding to the work from the part program storage means based on the external information. Variable holding means for holding the external information as a numerical value corresponding to a variable, and Work size automatic measuring system, characterized in that those comprising a part program executing means for executing the selected part program with reference appropriate numerical value corresponding to the variable held in the variables holding means. 2. The external information includes position information of the work, and the control means obtains the position information of the work from a measured value in the process of measurement by the coordinate measuring machine, and then the variable. 2. The workpiece size automatic measuring system according to claim 1, wherein the position information of the work held by the holding means is replaced with the newly obtained position information of the work. 3. The external information fetching means includes an image pickup means for picking up an image of a work to be measured and outputting image information of the work, and the shape and position of the work based on the image information output from the image pickup means. 3. The work size automatic measuring system according to claim 1 or 2, further comprising: an image processing unit that recognizes as the external information.