JPS5988606A - Positional deviation inspector for article - Google Patents

Abstract

PURPOSE:To achieve an accurate inspection of positional deviation simply and inexpensively free from the shape and the size of article requiring no mechanical positioning apparatus by checking positional deviation of article from the center in the view taken from the area value of an object image existing within a window for observation of article. CONSTITUTION:A window generation circuit 82 is provided to generate a window for observing a specific area in a picture taken screen (view taken) with a camera. Therefore, only a pixel data in a specific area is taken out of a logic circuit 83 made of an AND gate and memorized into a data memory 84. Data memorized in the memory 84 is processed by mu-cpu 85. The mu-cpu 85 computes the area of an object image existing within four windows W1-W4, namely, area values S1-S4 of a shaped part. When S1-S2=DELTAy and S3-S4=DELTAx, DELTAx and DELTAy represent deviation of an object to be inspected from the center of the camera or the screen. Thus, based on the deviations DELTAx and DELTAy, the control of a handling is possible.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a product misalignment inspection device that is applied to a non-driving system for industrial products and the like.

For example, in a handling system using an industrial robot, the function of "eyes" to detect the position of the object to be inspected is required, and this invention provides the function of the "six eyes" to an industrial television camera (ITV camera). ) This is what we are trying to realize by using an image pickup device and its processing device.

FIG. 1 is a schematic diagram showing a conventional article handling system. In the same figure, 1 is a conveyor, 2 is a mineral product, and 31 is a conveyor.
t;j: light emitting element, 32 is a light receiving element, 4 is a stopper, 5
are the fingers of the handling device. That is, a stopper 4 and light emitting and light receiving elements (hereinafter simply referred to as sensors) 31 and 32 are provided at a predetermined position of the conveyor 1 for transporting the article 2, and the article is positioned by the stopper 4. The approximate size and timing of arrival are detected by a sensor, and predetermined information is given to fingers 5 provided at corresponding positions to move or store the articles one by one to a predetermined position. It is something to do.

In this case, the placement position and direction of the article on the conveyor, the shape of the article and the stopper, etc. are predetermined, so that the nodding can be performed correctly.
For example, if the shape, size, or placement position of the article changes, it may become impossible to handle it at all. Further, some articles are so soft that they are not suitable for mechanical positioning using a stopper or the like.

On the other hand, it is of course possible to image the object to be inspected using an imaging device such as an ITV camera, and then image-process the image signal to determine its position and orientation. Therefore, the cost is high and the processing time is usually long.

This invention has been made in view of the above points, and is a simple and inexpensive test that does not require a mechanical positioning device, is independent of the shape and size of the article, and can accurately inspect for misalignment. The purpose is to provide equipment.

The feature is that the image processing technology described above is essentially applied, but the object image of the article is captured by an imaging device, and the article observation window (window) of a predetermined area within the field of view of the imaging device. ), and the positional deviation of the article from the center of the imaging field of view is inspected from the area value of the subject image existing within the window.

Embodiments of the present invention will be described below with reference to the drawings.
, 2. FIG. 2 is a schematic block diagram showing the handling system according to the present invention, FIG. 3 is a block diagram showing the configuration of the video controller according to the present invention, and FIG. 4 is an explanatory diagram for explaining the image processing operation according to the present invention. It is.

In FIG. 2, 6 is a handling device, 7 is an imaging device such as an ITV camera, 8 is a video controller, 9 is a handling controller, and other symbols are the same as those shown in FIG.

That is, the article 2 conveyed by the conveyor 1 is imaged by the imaging device 7 installed at a predetermined position and converted into an electrical signal. The video controller 8 detects the positional deviation of the article 2 from the center of the imaging device 7 based on the video signal from the imaging device 7 using a determination method as described below. Handling controller lj: Sends a predetermined signal to the handling device 6 based on the signal from the video controller 8, controls the rotation angle or the opening/closing angle of the fingers 5, etc. to handle the article. As shown in FIG.
7-CPU), a read-only memory (I(,OM) 86, and a random access memory (R).
AM)87. Keyboard 88 and CRT (Cath
Ray Tube), etc. In addition, in the same figure, it is a 7Fi imaging device.

The operation will be explained.

A video signal provided via the imaging device fi7 is binarized at a predetermined threshold level in a binarization and screen division circuit 81, and is also quantized or pixelized.

Window generating circuits 82t-, , t are windows for observing a predetermined area within the imaging screen (imaging field of view) of the imaging device, that is, a circuit for generating a window;
Therefore, only pixelated data within a predetermined area is taken out from the logic circuit 83, which is constituted by, for example, an AND gate, and stored in the data memory 84. Note that it is sufficient to know Kf:j for generating the window, and the coordinates of the opening and closing positions of the window in the X and Y directions of the imaging screen of the imaging device.
The Y coordinate position information is stored in a fixed memory (for example, RO in Figure 3).
M86), a method of specifying the position information regarding the window as appropriate each time via an input device such as a keyboard (for example, the keyboard 88 in Figure 43), and storing it in the memory (for example, RAMa7 in Figure 3), etc. However, the latter method is suitable for generating windows of arbitrary shapes. Regarding this point, the non-applicant has already proposed, so if necessary,
See No. 7-71499.

The data stored in the memory 84 in this way is p-
The fourth section explains how to process the CPU85.
This will be explained with reference to the figures. In addition, FIG. 4 shows the case where the contents of the data memory are monitored, P is the monitor screen,
PO is a subject image, and W1 to W4 are windows. That is, the figure is an image of an article with a circular cross section, and the image is shown as PO, while the rectangular window W
1 to W4 are generated with the positional relationship as shown.

/7-cpu85tj:, these four windows W1
The area of the subject image existing within ~X24, that is, the area value 81~S4 of the diagonally shaded portion is calculated. In this case, since the imaging screen is divided into minute pixels and the unit area of each pixel is known in advance, JF Jun can count the number of pixels representing the subject image existing within the shaded area. According to K, the area value can be determined. Next, the calculation 1-82 3-s4 is performed for each area value thus obtained. Here, 5l-82-Δy 53-
When s4=ΔX, ΔX and Δy represent the amount of deviation of the inspection object from the center of the imaging device or screen. Therefore, it can be seen that in the handling system as shown in FIG. 2, the handling device can be controlled based on the deviation amounts ΔX and Δy. In addition, ΔX(2M
) = 0 indicates that there is no shift in the left/right (vertical) direction, Δχ (Δy) > 0 indicates a right (up) shift, and ΔX (Δ
It goes without saying that y) <0 represents a left (downward) shift. In the above, the image of the subject existing within the window is determined, but conversely, the area value of the portion that does not overlap with the image of the subject within the window may be determined. In addition, the shape of the window is rectangular in the above example, but if the bare windows have the same size and shape, such as Wl and W2 and W3 and W4, which are in an axially symmetrical positional relationship, it can be a triangle or a pentagon. But it's good. Furthermore, although the case where the cross-sectional shape of the article is circular has been described, it is clear that the cross-sectional shape of the article may be an ellipse, a rectangle, or even a polygon as long as it is symmetrical with respect to the X and Y axes. However, this invention is applicable only when the article moves in parallel in either the Y-axis or the Y-axis direction, and cannot be detected when the article rotates in any direction within the X-Y axis plane.

As described above, according to the present invention, it is possible to easily and inexpensively detect the amount of positional deviation of an article from the center of the imaging screen, so that the article can be simply transferred from one conveyor to another, and the article can be moved to a predetermined location. This has the advantage that articles of different sizes and shapes can be easily, inexpensively, quickly, and precisely handled in barrequising, which is stacking up, and depalletizing, which is the reverse operation. Further, since it uses an imaging device, it can be easily handled when changing the shape or size of the article by simply changing the manner in which the window is generated, so it can be said to be extremely flexible.

Note that this invention can be widely applied not only to the above-mentioned no-end ring system but also to automation of marking, printing, labeling, or cutting processes, and in some cases to the measurement of eccentricity II of circular articles. can do.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing a conventional example of a non-driving system, FIG. 2 is a schematic configuration diagram showing the overall system according to the present invention, and FIG. FIG. 4 is an explanatory diagram for explaining the calculation operation according to the present invention. Description of symbols 1... Conveyor, 2... Article to be inspected, 31... Light emitting element, 32... Light receiving element, 4... Stopper , 5--Finger, 6... No. 1 handling device, 7...
- Imaging device (TV camera), 8... Video controller, 9... Handling controller, 81... Binarization/screen division circuit, 82...
...Window generation circuit, 83...-Logic circuit, 84...Data memory, 85... Arithmetic control unit (μ-CPU), 86... Read-only memory (I (, OM), 87... Random access memory (RAM), 8B... Keyboard, 89-... CRT Agent Patent attorney Akio Namiki People Patent Attorney Kiyoshi Matsuzaki Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] an image capturing means for capturing an image of an object that is not symmetrical with respect to at least orthogonal X and Y coordinate axes from vertically above the X and Y coordinate plane; and an image dividing means for binarizing the image signal at a predetermined threshold level and converting it into pixels. , window generating means for generating bare windows of congruent shapes at symmetrical positions sandwiching the X and Y axes passing through the center of the imaging field of view of the imaging means; and the pixelated windows existing in each window. comprising a storage means for extracting and storing the subject image signal, and a calculation means for computing the area values of the subject images existing in each window based on the stored data and comparing the area values for each bear, A positional deviation inspection device for an article, characterized in that the positional deviation of the object to be inspected from the center of the imaging visual field is inspected based on the calculation result.