JP2799032B2 - Visual recognition position correction method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a system in which correction by visual recognition using a television camera or the like is applied to accurate positioning by a robot or the like at a position taught in advance. In relation to
In particular, the present invention relates to a visual recognition position correction method suitable for an automatic component mounting machine on a printed wiring board, which is called a mounter or the like.

[Conventional technology]

When mounting electronic components on a printed wiring board, first, using a standard printed wiring board, teaching (teaching) of the mounting position is performed, and thereafter, the electronic components are placed at the position given by the teaching. At this time, it is difficult to maintain the predetermined accuracy only by the positioning based on the teaching data due to the displacement of the mounting position on the mounter on the printed wiring board or the displacement of the pattern of the printed wiring board itself. .

Therefore, conventionally, with a television camera,
A so-called visual recognition correction method has been applied, in which image data of a land serving as a positioning point is taken in for each teaching point, and the displacement of the land is corrected by analyzing the image data. This can be seen in JP-A-185105, JP-A-63-265104 and JP-A-1-173804.

[Problems to be solved by the invention]

The above-mentioned prior art does not take into consideration that an imaging field of view of a television camera (hereinafter, referred to as a TV camera) used for visual recognition cannot be so widened, and the above-described misalignment at the teaching point. When the amount becomes large, there is a problem that an imaging target such as a land goes out of an imaging visual field, and the mounting operation is stopped.

The reason why the field of view of an image captured by a TV camera or the like cannot be widened is as follows. That is,
If the imaging field of view is widened, it may be possible to prevent the object to be imaged from deviating from the field of view, but on the other hand, the resolution per pixel becomes rough and the required measurement accuracy cannot be maintained. This is because if the imaging field of view is too wide, a plurality of imaging objects enter the same field of view, and it becomes difficult or impossible to specify a necessary object.

An object of the present invention is to ensure that an imaging target is always within an imaging field of view, while maintaining necessary measurement accuracy,
It is an object of the present invention to provide a visual recognition position correction method capable of sufficiently suppressing the occurrence of downtime due to the stop of operation.

[Means for solving the problem]

In order to achieve the above object, a teaching position at a teaching point next to the teaching point is sequentially corrected based on a position correction result detected by visual recognition at each teaching point.

[Action]

The position correction amount detected by visual recognition at each teaching point should represent the amount of deviation at this teaching point and also be an amount for estimating the amount of deviation at the next teaching point. Therefore, if the position of the next teaching point is corrected based on the position correction amount, the position correction amount moves the imaging visual field to a position where the imaging target is expected to be shifted at the next teaching point. And the imaging target can always be kept within the imaging field of view.

〔Example〕

Hereinafter, the visual recognition position correction method according to the present invention,
This will be described in detail with reference to the illustrated embodiment.

First, a first embodiment in which the present invention is applied to a mounter will be described with reference to FIG.

In FIG. 1, 1a represents a printed circuit board installed at a mounting position instructed in advance to a mounter,
Reference numeral 1b denotes a printed circuit board at a position actually set by the mounter during the mounting operation.

First, at the time of teaching, the printed circuit board 1a is set in the mounter, and the positions of the lands 2a and 3a are taught. At this time,
The visual field recognition areas for recognizing the lands 2a and 3a are respectively 5a and 6a.

Next, when the components are actually mounted on the printed circuit board, the components are mounted in the order taught. Therefore, the lands 2b (Nth) and the lands 3b (N + 1) of the printed circuit board 1a are mounted in this order.

Therefore, first, for the land 2b on which the component is to be mounted, the position in the visual field is determined using the visual recognition area 5a when the land 2a is taught.

Since the position obtained at this time is represented as a position in the visual recognition visual field, it is converted into a position in the coordinate system held by the mounter.

After converting to the position of the mounter, the mounter mounts the component at that position.

In parallel with this, the mounter obtains the difference in position between the land 2b on which the component is actually mounted and the land 2a taught, and sets them as position differences Δx, Δy as shown in FIG. . Then, the obtained differences Δx, Δy are used as visual recognition position correction amounts.

Next, similarly to the land 2b, the component is mounted by visually recognizing the land 3b on which the (N + 1) th component is mounted. However, as shown in FIG.
Since 3b is outside the visual field of the visual recognition area 6a when teaching, it cannot be recognized by the conventional technology.

Therefore, in this embodiment, for this reason, the visual recognition position correction amounts Δx and Δy previously obtained at the time of the N-th mounting are used, and the visual recognition position 6a is moved by these correction amounts to obtain a new visual recognition position. Get position 6b.

According to the corrected visual recognition position 6b, since the land 3b is in the field of view, the position of the land 3b is obtained using this.

And the position of the land 3b obtained at the visual recognition position 6b is
The position in the visual field is converted to the position of the mounter, and the component is mounted in the same manner as in the land 2b obtained at the Nth position.

In parallel with this, for the next N + 2nd visual recognition position correction, the difference between the positions of the lands 3a and 3b is similarly obtained, and this is used as a new visual recognition position correction amount.

 Thereafter, these processes are repeated.

Therefore, according to this embodiment, in the related art, an object that has deviated from the visual recognition area can also be taken into the area. .

Next, a second embodiment of the present invention will be described with reference to FIG.

In the embodiment shown in FIG. 3, the position of the land 2a at the time of teaching and the position of the land 2b at the time of actually mounting a component are greatly separated, and cannot be recognized in the visual recognition area 5a at the time of teaching. In FIG. 7, a visual recognition area for search is indicated by 7, and the visual recognition area 7 is sequentially moved upward and left and right obliquely around the visual recognition area 5 a at the time of teaching. Land within the visual field for each position
This is to check whether or not 2b exists and perform a search.

When the land 2a is found, the operation shifts to the same operation as the first embodiment described with reference to FIG.

FIG. 4 shows a procedure necessary for a process combining the first and second embodiments, and shows a series of operations from the start of the mounting operation by the mounter to the end of the mounting. Hereinafter, description will be made with reference to FIG.

In S1, prior to mounting, the memory is initialized to clear the visual recognition position correction amount.

In S2, the taught position data and the like are read from the memory according to the mounted step number.

In S3, when measuring the position of the land using the visual sensor, if the land is not found in the visual field of view, the mounter is moved and the process of searching for the land is performed again. deep.

In S4, the visual recognition position correction amount is added to the taught position data read in S2, the field of view is corrected to a position slightly apart from the time of teaching, and the mounter is moved to the corrected position.

In S5, the position of the land is obtained as coordinates in the visual field using the visual sensor at the position moved in S4.

In S6, from the result of S5, if there is no land in the field of view, the process proceeds to S11, and if there is a land in the field of view, S
Move the processing to 7.

In S7, a land exists in the field of view, based on the judgment of S6,
Since the position is obtained from the visual sensor, the position coordinates in the visual field are converted into mounter coordinates, and the mounter is moved to the converted position.

 In S8, components are mounted on lands.

In S9, the difference between the taught position data read in S2 and the land position data obtained in S7 is calculated in both the x and y directions (the S2 data is subtracted from the S7 data), and the result is used as a new value. The visual recognition position correction amount is replaced with the currently set visual recognition position correction amount.

At S10, it is determined whether the component mounted at S8 is a component of the final step, and if it is a component of the final step, the process is performed.
And end. If it is not the last step, step NO. Is advanced, the processing is shifted to S2, and mounting is continued.

In S11, since there is no land in the visual field of view according to the judgment in S6, the search movement amount (Δx, Δ) is obtained from the search movement amount storage table shown in FIG.
Read y).

In S12, the search movement amount read in S11 is further added to the value obtained by adding the taught position data read in S2 and the current visual recognition position correction amount. Then, the mounter is moved to the position indicated by the result.

In S13, even if the mounter searches around the teaching point to find the land, it may not be found.Therefore, if the mounter does not find it even after executing a certain number of times, the search is performed, and the component of that step is In order to jump over and start mounting the component of the next step without mounting, the search counter is incremented, the number is compared with a certain value, and if it exceeds a certain value, the processing is performed. Move to S10. If the value is equal to or smaller than the predetermined value, the process proceeds to S5 so as to perform the land search again.

Therefore, by executing the processing procedure shown in FIG. 4, the operations shown in FIGS. 1 and 3 can be obtained, the land can always be included in the imaging visual field, and the component mounting operation can be continued. I can do it.

〔The invention's effect〕

According to the present invention, the imaging target can always be reliably contained within the imaging field of view while maintaining the required measurement accuracy. Therefore, the present invention is applied to a mounter or the like to reduce downtime caused by stopping the component mounting operation. The generation can be sufficiently suppressed, and the effect of greatly contributing to the improvement of the operation rate can be obtained.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of the operation of the first embodiment of the visual recognition position correcting method according to the present invention, FIG. 2 is an explanatory diagram showing the relationship between the position of the taught data and the actual land position, and FIG. FIG. 4 is an operation explanatory diagram of the second embodiment of the present invention, FIG. 4 is a flowchart showing a processing procedure in the embodiment of the present invention, and FIG. 5 is an explanatory diagram of a search movement amount storage table in one embodiment of the present invention. . 1a: Printed circuit board at teaching position, 1b: Printed circuit board at actual storage position, 2a ... Land taught at Nth position, 2b ... Land at Nth position, 3a ... N + 1th taught at Land, 3b ... N + 1 land to be mounted.

Continuation of the front page (56) References JP-A-1-238200 (JP, A) JP-A-1-227499 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) H05K 13 / 04

Claims (2)

(57) [Claims] 1. A method for visually recognizing a plurality of imaging objects existing on a printed wiring board surface based on respective teaching positions for visual recognition and placing each imaging object within an imaging field of view. Based on the position and the amount of deviation of the position of the imaging target detected by visual recognition based on the taught position, the amount of displacement of the taught position for the next visual recognition of the taught position is calculated. A visual recognition position correction method, wherein the next teaching position is corrected based on the amount. 2. The visual recognition device according to claim 1, wherein when the visual recognition is performed at the teaching position, if the visual recognition cannot be obtained because the imaging target is not present in the imaging visual field, a predetermined distance from the position. A visual recognition position correction method, comprising: performing position correction for visual recognition that sets a positioning point at a distant position.