JP2625955B2 - Recognition method of work assembly means in production system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention recognizes a work assembling means used for assembling an arbitrary work in a production system having a plurality of work assembling means for assembling works of the same shape. The way to do it.

[Conventional technology]

Body components having the same shape are respectively assembled on a plurality of jig carts (jig trays) having jigs of the same specification, and the body components are assembled on a plurality of jig carts having jigs of the same specification. Recently, there has been proposed a vehicle production system in which a vehicle main body is assembled using the vehicle.

Since the jig cart used in this vehicle production system has a lightweight structure, it may be deformed due to aging or the like. The deformation of the jig cart causes deformation of a body component assembled on the jig cart, and further causes a dimensional deviation of a body main body formed using the body component.

Therefore, in such a vehicle production system, the dimensions of each part of the assembled body main body are checked, and a defective body having an error of this dimension exceeding an allowable value is prevented from flowing to the subsequent process.

[Problems to be solved by the invention]

By the way, in order to prevent the generation of a large number of defective bodies, it is necessary to find a defective jig cart that causes the generation of a defective body.

Therefore, it is conceivable to manage the feed of the jig carts as work assembling means using a sequencer or a computer. However, such means has a drawback that it cannot be applied after a line-out in which the body arrangement is random.

An object of the present invention is to provide a device capable of accurately recognizing work assembling means used for assembling an arbitrary work even after line-out in view of such a situation.

[Means for solving the problem]

The present invention is applied to a production system having a plurality of work assembling means for assembling works of the same shape, and engraving a mark for specifying the work assembling means on the work assembled by each of the work assembling means. A process of recognizing the mark by a television camera, and a process of recognizing the work assembling unit by processing an image of the mark captured by the television camera. In the step of engraving, a predetermined linear pattern as a mark component is selectively engraved at a plurality of engraving positions set on the work, and in the imaging step, the mark of the television camera is blurred. In the step of imaging the mark and recognizing the work assembling means, the image of the mark is replaced with the image of Binarized based on the presence or absence, the 2
The present invention is characterized in that the corresponding work assembling means is recognized from the result of the binarization.

[Action]

According to the present invention, since the mark is captured by the television camera whose focus is blurred, the outline of the image of the pattern constituting the mark is expanded. Therefore, the binarization processing of the image of the pattern becomes more accurate, which improves the recognition accuracy of the corresponding work assembling means.

〔Example〕

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 conceptually shows an example of a vehicle production system to which the present invention is applied.

In FIG. 1, jig carts (jig trays) 1, 1,..., Which are work assembling means, each include a work assembling jig of the same specification (not shown) for assembling the left body side 3 as a work. Similarly, the jig carts 2, 2,..., Which are the work assembling means, each have a work assembling jig (not shown) of the same specification for assembling the right body side 4 as the work.

.. And 2, 2,... Are moved along a predetermined route by moving means (not shown).

A jig cart 5, which is another work assembling means, is for assembling the main body 6 using the left body side 3, the right body side 4, and the like. A plurality of jig carts 5 are also used, and they are provided with work assembly jigs (not shown) of the same specification for assembling the main body 6.

The jig carts 1, 2, and 5 are provided with stamping machines 7, 8, and 9, respectively. The marking machine 7 of the jig cart 1 is used to stamp a mark for specifying the jig cart 1, for example, a mark indicating the cart number on the left body side 1, and FIG. A specific configuration of the mark 10 formed by the embossing is illustrated.

The mark 10 shown in the figure has a configuration in which a pattern of N is selectively imprinted on a plurality of engraving positions 10a to 10e set at predetermined positions on the left body side 3. In the example of the mark 10, the above-described pattern is used. Positions 10a, 10c and 10e have been selected as marking positions.

The individual marking positions 10a, 10b, 10c, 10d, and 10e are weighted as 1, 2, 4, 8, and 16, respectively.Therefore, if the presence or absence of the pattern at each position is detected, this mark 10 It is possible to determine which jig cart 1 has been used for engraving.

That is, when the presence or absence of the pattern N is represented by binary codes 1 and 0, the mark 10 shown in FIG.
The decimal number 21 is derived from this. Accordingly, it is found that the number of the jig cart 1 provided for assembling the left body side 3 on which the mark 10 is engraved is 21.

Stamping machines 8 and 9 provided on jig carts 2 and 5
This is also provided for stamping a mark 10 having a structure similar to that described above at an appropriate position on the right body side 4 and the main body side 6.

The mark 10 is stamped at an appropriate position that cannot be seen from outside.

In this embodiment, the pressing force of a compressor (not shown) set at a predetermined position or the impact force of a hammer is used for the stamping machine 7,
Although the mark 10 is imprinted by acting on 8 and 9, it is also possible to attach the above-mentioned compressor or hammer to these engraving machines 7, 8 and 9.

The main body 6 assembled by the jig cart 5 is transported to a body dimension measurement position 11, where it is positioned.

Robots 12 and 13 for dimension measurement are arranged on one side and the other side of the body dimension measurement position, respectively.

These robots 12 and 13 are equipped with a television camera and a laser measuring device using a CCD, and measure the dimensions of several main parts of the body 6 while being guided in the direction of the arrow by guide means (not shown). Is added to the microprocessor 15 via the robot controller 14 shown in FIG.

The microprocessor 15 compares the dimension data (reference dimension data) of the master body with the dimension data measured by the robots 12 and 13. If the error of the latter with respect to the former is equal to or larger than an allowable value, the corresponding main The display 16 indicates that the body 6 is defective.

On the other hand, television cameras 17, 18, and 19 using a CCD are arranged at the body size measurement position 11. The camera 17 captures the mark 10 stamped by the stamping machine 8, the camera 18 captures the mark 10 stamped by the stamping machine 9, and the camera 19 stamps the stamp 10 by the stamping machine 7. In order to image the engraved marks, they are arranged at predetermined positions.

As shown in FIG. 4, each of the cameras 17 to 19 has its optical axis directed perpendicular to the mark stamping surface 6a of the body 6. In the vicinity of the embossing surface 6a, fiber light guides 21 and 22 for guiding light projected from the light source 20 to the embossing surface 6a are provided.

In addition, in this embodiment, in order to direct more reflected light from the concave groove formed by embossing to the camera 17-19 side,
The optical axes of the light guides 21 and 22 are inclined with respect to the embossing surface 6a (the inclination is 30 °).

By the way, when the focus of the cameras 17 to 19 is blurred and the mark 10 shown in FIG. 2 is imaged, the image becomes as shown in FIG. That is, the pattern N is a linear pattern combining line elements, but if the focus is defocused as described above,
Since the outline of each line element constituting the pattern is expanded, the image of the pattern N becomes a substantially elliptical image due to the overlap of the outlines.

In order to clearly capture the shape of the pattern with the cameras 17 to 19, it is necessary to sharply focus the cameras 17 to 19, but it is determined whether or not the pattern exists at the marking positions 10a to 10e of the mark 10. For this reason, in order to more appropriately binarize the image of the mark, it is desirable to defocus the cameras 17 to 19 and enlarge the image of the pattern as described above.

Therefore, in this embodiment, the focus of the optical system in the cameras 17 to 19 is blurred so that the mark 10 is imaged as shown in FIG.

Now, when a measurement start signal as shown in FIG. 5A is given to the microprocessor 15 from a sequencer (not shown), the microprocessor 15
Are output to the image processing unit 23 at an interval of time T ₁ (for example, within 5 seconds), and as a result, the image processing unit 23 outputs (c), (d), and (e) in FIG. The image images of the cameras 17, 18 and 19 are processed in each signal generation period shown in FIG. That is, since the images of the mark 10 obtained by the cameras 17, 18, and 19 are as illustrated in FIG. 6, based on the presence or absence of the elliptical pattern image at each of the marking positions 10a to 10e (see FIG. 2). The image of the mark 10 is binarized,
As a result, binary data 10101 indicating the contents of the mark 10, that is, the number of the jig cart used is created.

The image processing unit 23 outputs binary data based on the outputs of the cameras 17, 18, and 19, respectively, as shown in FIGS. These data are fetched and stored during the output of the data valid signal shown in FIG.

When the microprocessor 15 determines that the body 6 is a defective body having low dimensional accuracy based on the result of the dimensional measurement, the microprocessor 15 determines the number of the jig cart 5 used for assembling the body 6 and the number of the jig trolley. Based on the binary data, the numbers of the jig carts 1 and 2 used for assembling the left body side 3 and the right body side 4 constituting the body are recognized, and displayed on the display unit 16,
Record on the printer 24.

As described above, according to this embodiment, the jig cart 5 used for assembling the defective body, and the jig carts 1 and 2 used for assembling the left body side and the body side constituting the defective body are recognized. Since the jig cart is replaced or maintained based on the recognition result, it is possible to prevent a large number of defective bodies from being generated.

In the above embodiment, the pattern N shown in FIG. 2 is stamped as a component of the mark, but another pattern may be stamped instead of the pattern N. The point is that a pattern having good light reflectance, that is, a pattern having a large number of line elements and easy to binarize may be stamped.

It is conceivable to form the pattern of the mark 10 with paint such as pigment ink instead of engraving. However, in this case, it is necessary to dry the paint and wash off the paint in a later step. In addition, accurate image information cannot be obtained when a warp or the like is present on the mark forming surface, and the degree of ink adhesion to the mark forming surface is unstable due to rust-preventive oil attached to the body component. Become. Therefore, a mark drawn with pigment ink or the like lacks practicality as a mark attached to a body component of an automobile.

〔The invention's effect〕

According to the present invention, the work assembling means used for assembling an arbitrary work can be recognized even after line out. In addition, since the mark imprinted on the work is imaged by a television camera whose focus is blurred, the outline of the image of the pattern constituting the mark is expanded, and the binarization processing of the image of the mark becomes more accurate. As a result, The recognition accuracy of the work assembling means is improved.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an outline of a vehicle production system to which the present invention is applied, FIG. 2 is a diagram exemplifying a configuration of a mark, FIG. 3 is a block diagram showing a connection mode between a television camera and a robot, FIG. 4 is a conceptual diagram showing the arrangement of the television camera with respect to the mark, FIG. 5 is a time chart showing the operation of the image processing unit and the microprocessor shown in FIG. 3, and FIG. 6 blurs the focus of the camera. FIG. 5 is a diagram illustrating an example of an image of a mark obtained in a case where the mark is displayed. 1,2,5… Jig bogie, 3… Left body side, 4… Right body side, 6… Main body, 7,8,9… Engraving machine, 10… Mark, 12,13… ... Robot, 15 ... Microprocessor, 17-19 ... TV camera, 23 ... Image processing unit.

Claims (1)

(57) [Claims] The present invention is applied to a production system having a plurality of work assembling means for assembling works of the same shape, and engraves a mark for specifying the work assembling means on each of the works assembled by each of the work assembling means. A method of recognizing the work assembling means, comprising: a step of capturing the mark with a television camera; and processing the image of the mark captured by the television camera to recognize the work assembling means. In the step of engraving a mark, a predetermined linear pattern as a mark component is selectively engraved at a plurality of engraving positions set on the workpiece, and in the imaging step, the focus of the television camera is blurred. In the step of capturing a mark and recognizing the corresponding work assembling means, the image of the mark is displayed at Recognition method of the work assembling means binarizing based on the presence or absence of, from the binarization result in the production system characterized by recognizing the relevant workpiece assembly means.