JPH03167897A - Setting method of component-gripping position in component mounting apparatus by image recognition - Google Patents

Abstract

PURPOSE:To decide a component-gripping position at high speed by using a low-speed computer by a method wherein, when the component-gripping position is set after recognizing a component, the surface and the rear of the component are judged. CONSTITUTION:When a flag F is 0, picture-element data, covering one frame, supplied collectively one after another from an A/D converter 10 are taken into a RAM by using a first control means 1. For a picture element, a window (W) is set, by using a block-level grid as a reference, in a grid being set for every prescribed number of picture elements. When a black-level grid does not exist on the boundary of the W, the number of black-level grid inside the W is within a prescribed range and an the interval between black-level picture elements is within a prescribed range, it is judged that the position and the size of a component as viewed from a TV camera 8 are within a prescribed range. Coordinates of the center of gravity are computed and F=1 is set. Then, the surface and the rear are discriminated based on the sign of the difference of counterclockwise angle with reference to a reference line in the horizontal direction of a long-axis line and a short-axis line which connect a farthest point and a nearest point on a contour from the center of gravity of the component. Then, a gripping position where the component is to be sucked is computed.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a component mounting device that automatically and sequentially mounts components onto a so-called printed circuit board (hereinafter simply referred to as a board). The present invention relates to a component gripping position setting method in an image recognition component mounting device for mounting.

BACKGROUND ART A component mounting device operated by such image recognition supplies electronic components randomly (in an unaligned state) onto a conveyor in order to correctly mount electronic components on a board, which are difficult to supply in an aligned manner because they have weak terminals. ．． A television camera takes images of the electronic components placed on the screen, and the resulting image data is processed to determine the shape, position, and orientation of each component.

In conventional image recognition component placement devices, the program for processing image data and setting the component gripping position is complex, and if the component placement speed is to be fast and consistent, a high-speed computer is required, resulting in high costs and impractical use. There was a problem.

Summary of the Invention [Object of the Invention] An object of the present invention is to provide a component gripping position setting method in an image recognition component mounting apparatus that is formed by a low-speed computer and can set the component gripping position at high speed. be.

[Structure of the invention] An image signal is generated by imaging electronic components randomly placed on a component placement surface, the image signal is processed to generate pixel data constituting a two-dimensional screen, and the pixel data is A component gripping position setting method in an image recognition component mounting apparatus that sets a gripping position of one of the electronic components on the component mounting surface based on the presence of one group of black level data among the pixel data. a step of finding the equivalent ellipse and principal axis of inertia of the first group of black level data; and a step of finding the farthest point from the center of gravity to the outside of the region of existence, and a length connecting the center of gravity to the nearest point and the farthest point from the center of gravity to the outside of the region of existence. a step of determining the axis and the short axis; a step of determining the front and back sides of the component based on the direction from which one of the long and short axes is viewed from the other; and a step of gripping the component based on the center of gravity position according to the result of the front and back determination. A method characterized by setting a position.

[Operation of the Invention] In the image recognition component mounting device according to the present invention, when setting the component gripping position after recognizing the component, the front and back of the component are discriminated, and the component gripping position is set using relatively simple calculations. ing.

Embodiments Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

First, with reference to FIG. 1, an image recognition component mounting apparatus for carrying out a component gripping position setting method according to the present invention will be described.

In this device, a first control means 1 drives a motor 3 for operating a component supply device 2, and several electronic components 5 (in this case, light emitting elements) are randomly transferred from the component supply device 2 onto a conveyor 4 ( In other words, they are dropped in an unaligned state. Then, a motor 6 for operating the conveyor 4 is driven, and the light emitting elements 5 dropped onto the conveyor 4 are brought to a component supply position 9 where they can be imaged by a television camera 8 serving as an imaging means. An image signal generated by the television camera 8 is converted into pixel data via an A/D converter 10 and sent to the first control means 1.

The first sub-control means 1 learns the shape, position, and orientation of each light emitting element 5 at the component supply position 9 based on this pixel data, and drives the motor 13 for operating the X-Y table 12 to drive the component transport chuck 14. Then, the light emitting element determined to be transported first is brought to a position where it can be gripped, and the light emitting element is gripped.

Then, this gripped light emitting element 5 is turned over by a front-back reversing device 15.
If the delivered light-emitting element is turned upside down, the front-back reversing device 15 is operated to correct the posture so that the light-emitting element 5 always faces up, and the index table 1
Transfer it to the index chuck 18 above 7. The index table 17 is connected to the cam mechanism 2 by the main motor 19.
The index chuck 18 is rotated intermittently by 36" by controlling the operation of the cam mechanism 20 by the first control means 1.The index chuck 18 is rotated at equal intervals (366 pitches) on the index table 17. te1
It is provided in 0 locations. The index chuck 18 is operated by a cam! aHa
The gripping claws are opened by applying mechanical force by the index chuck drive devices 23 and 24 whose operation is controlled through t 2 0. When this mechanical force is released, the gripping claws are closed.

As mentioned above, the index table 17 has 36a as 1
The television camera 26, the terminal handling device 27, and the terminal bending device 28 are rotated intermittently as pitches, and the television camera 26, the terminal handling device 27, and the terminal bending device 28 correspond to the positions advanced by one pitch from the above-mentioned parts supply point.
, two television cameras, and a component mounting chuck 30 are provided. The position where this component mounting chuck 30 is placed is the above-mentioned component ejection location, and the index chuck 18 that grips the light emitting element 5 is applied with mechanical force by the index chuck drive device 24 at this position to grip the light emitting element. The state is released and the part is transferred to the component mounting chuck 30.

The above index chuck drive devices 23, 24, terminal handling device 27, terminal bending device 28, and component mounting chuck 30 are driven by the main motor 19 via the cam mechanism 20 and clutch 21 whose operation is controlled by the second control means 22. be done. Further, the timing of driving the terminal handling device 27, the terminal bending device 28, and the component mounting chuck 30 is based on a signal from the encoder 31. The second control means 22 first recognizes the state of the terminal of the light emitting element 5 gripped by the index chuck 18 based on the image signal from the television camera 26, and operates the terminal handling device 27 accordingly. Therefore, the terminals 5a of the light-emitting element 5, which had been deformed as shown in FIG. 2, are handled with their tips facing toward their ends, and are shaped parallel to each other as shown in FIG. Next, the second control means 22 operates the terminal bending device 28 to bend the terminal 5a by about 90 degrees as shown in FIG.

Thereafter, the second control means recognizes the state of the terminal 5a of the light emitting element 5 based on the image signal from the television camera 29, and if it determines that the molding state of the terminal 5a is good, it operates the index chuck drive device 24. Then, the light emitting element 5 is released from being held by the index chuck 18, and the light emitting element 5 is held by the component mounting chuck 30. Then, a motor 34 for operating the X-Y table 33 is driven, and a printed circuit board 35 is brought to be mounted with the light emitting element 5.

Thereafter, the second control means 22 rotates the component mounting chuck rotation motor 37 to rotate the component mounting chuck 30 to an appropriate angular position, thereby determining the angular position of the light emitting element 5 with respect to the printed circuit board 35. Then, the component mounting chuck 30 is lowered, and as shown in FIG.
The light emitting element 5 is attached to the light emitting device 5. At this time, the terminal 5a of the light emitting element 5 is inserted into the terminal insertion hole 35 formed in the printed circuit board 35.
a, and its tip portion protrudes to the lower surface side of the printed circuit board 35. The second control means 22 inspects the conductivity of the terminal 5a using three continuity check/terminal cutting devices, and if the continuity is good, cuts the tip of the terminal 5a using the three continuity chuck/terminal cutting devices. and cut it to the specified length.

On the other hand, when the second control means 22 recognizes that the terminal continuity test result by the continuity chuck/terminal cutting device 39 is defective, the second control means 22 causes the component mounting chuck 30 to remove the light emitting element 5 from the printed circuit board 35. For recovery, it is stored in the defective parts storage section 40, and subsequent light emitting elements are immediately mounted.

Thereafter, the above series of operations are performed for each light emitting element to be mounted on the printed circuit board 35.

Next, the component recognition operation in the first control means 1 will be explained with reference to FIG.

The means for performing the component recognition operation by the first control means is a CPU.
, RAM, and ROM. FIG. 6 is a flowchart showing a program executed by this microcomputer, which is executed at a desired timing by interrupting the program controlling the control operation of the motor 13 and component transport chuck 14 by the first means.

In this program, first, it is determined whether the flag F is equal to 1 (step Sl), and when F is equal to 0, the pixel data sequentially supplied from the A/D converter 10 is collected for one frame. The data is imported into a predetermined area in the RAM (step S2).

Note that when it is determined that it is F-1, step S18 described below is performed.
to go into. FIG. 7 shows an example of a one-frame image represented by pixel data, and in this image, electronic components dl, d2, and d3 are placed on the conveyor 4 in an unaligned state. It's showing. As shown in FIG. 8, according to the present invention, grids Gε (t-1, . . . 19G) are set at predetermined pixel intervals (for example, 100 pixels) in the vertical and horizontal directions in one frame of image. Then, in the area outside the existing window, check in numerical order starting from the lowest number G(,) (step S3).
, when a black level grid is found, an area of a predetermined size, ie, a window W, is set based on this detected black level grid (see FIG. 9) (step S4). Next, it is determined whether a black level grid exists on the boundary of this window W (step S5). For example, when there is a black level grid on the window border, the 10th
As shown in the figure, since the parts are close to each other and it is not suitable for parts suction, the process goes to step S3 to perform a black level grid detection operation from the lowest number Gt to the highest number in the area other than the already set window. return. On the other hand, if there is no black level grid on the window boundary, it is determined by 1'j1 as soon as the number of black level grids within the window is greater than a predetermined value (step S7). If the number of black level grids in the window is not within the specified value range, the size of the target component is outside the specified range, or the component is placed at an angle to the planting surface and cannot be suctioned. It is determined that it is not suitable and the process returns to step S3. On the other hand, when it is determined that the number of black level grids in the window is within the predetermined value range, the area of the target component as seen from the television camera 8 is
As shown in the figure, it is assumed that the conditions are within the specified range, and the next step s8 is the determination operation. In step S8, as soon as the maximum distance ll#X between black level pixels in the horizontal direction and the maximum distance Y between black level pixels in the vertical direction within the window are smaller than predetermined maximum values XMx and YMx. Determine. As shown in Figure 12,
If XMx and Y<YMX are both established, it is assumed that the size of the target part is within the specified range, and the process proceeds to step s9 for the next area check.

In step S9, it is determined whether the number of black level pixels within the window is between a predetermined minimum value NMN and a predetermined maximum MNMX. If the number of black level pixels in the window is not between NMN and NMX, the area of the component is outside the specified range, so the shape of the component is determined to be abnormal or the orientation of the component is incorrect, and the process returns to step S3. On the other hand, if it is determined that the number of black level pixels in the window is between NMN and NMX,
In preparation for calculating the component suction or gripping position, the center of gravity position coordinates of the target component are calculated (step S10). Since the method for calculating the coordinates of the center of gravity position is well known, it will not be described in detail here. Next, in step S11, it is determined whether or not a flag F indicating that the operation up to the calculation of the suction position has already been performed for one component is set for the captured one frame image. When it is determined that the flag F is 1, the suction position calculation has already been completed for one component, so the center of gravity position coordinate data for the component in the current setting window is stored (step S12). Return to main routine. On the other hand, when F-0 is determined, black level data on the equivalent ellipse and principal axis of inertia of the target part d1 is calculated as shown in FIG. 13 (step S13). This operation is also well known and will not be described in detail here. Next, in step S14, as shown in FIG. 14, a long axis g1 and a short axis g2 extending between the center of gravity and the farthest and nearest points on the contour from the center of gravity of the part are determined. Next, assuming that the counterclockwise angles of g1 and g2 with respect to the horizontal rightward alignment line γ are 01 and θ2, Δθ=θ1−
02, and when Δθ>180°, Δθyo Δθ−36
0°, and when Δθ<-180°, Δθ - Δθ + 36
Set to 0°. This way -180″<Δθ<180'
Then, front and back discrimination is performed based on the sign of Δθ (step S15).

Next, in step S17, the position at which the target part should be picked up by the suction means that picks it up from the mounting surface, that is, the gripping position is calculated. The coordinates of this suction position (P x,
P y) can be obtained by calculating the following equation (1) or (2).

PF=GF+G! 'sin (180°-θGP 10θ
MX) Here, Gx and Gy are the coordinates of the center of gravity position calculated previously, and GP is the distance between the center of gravity and the suction position, which is determined in advance for each type of component. θGP is the distance between the center of gravity and the suction position, and θcp is the angle between the line connecting the center of gravity and the suction position α and the principal axis of inertia, and is determined in advance for each type of component. Further, θM is the angle formed between the principal axis of inertia obtained in step S13 and the horizontal direction.

In addition, in the case of the R state (table) in which the longitudinal part of the part extends to the right as shown in Fig. 15 (A), using the above equation (1), the longitudinal part of the part extends as shown in Fig. 15 (B) In the case of the L state (back) extending to the left, formula (2) is used.

When the suction position coordinates Px, Py are obtained in this way, the flag F is set to 1 (step S17), and then the process returns to step S3.

Note that when F-1 is determined in step S1, the next window data stored in step 512 is imported as the current one (step S18) without importing image data, and the flag F is set. After setting it to zero (step S19), the process proceeds to step S13.

l In this way, steps S13 to S17 are executed again, and step S3 is entered to search for the next part. If no part is found, the process returns to the main routine, and at this time the conveyor is moved one pitch (step S20).

Effects of the Invention In the component gripping position calculation method according to the present invention, when calculating the component gripping position, the front and back sides of the component are discriminated, and the component gripping position can be set using a relatively simple calculation formula, so the calculation speed is improved. do.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an image recognition component mounting apparatus that executes the component recognition method of the present invention, and FIGS. 2 to 5 are
FIG. 6 is a perspective view illustrating the operation when aligning the terminals of the target parts, and FIG. 6 is a flowchart showing a subroutine of the control means controlling the image recognition operation in the apparatus of FIG. 1, and FIGS. 7 to 15 (A) , (B) is a diagram showing the calculation contents of the subroutine operation shown in FIG. 6.

Claims (1)

[Claims] An image signal is generated by capturing an image of electronic components randomly placed on a component placement surface, the image signal is processed to generate pixel data constituting a two-dimensional screen, and the pixel data is A component gripping position setting method in an image recognition component mounting apparatus that determines a gripping position of one of the electronic components on the component mounting surface based on the presence area of one group of black level data of the pixel data. a step of finding the equivalent ellipse and principal axis of inertia of the first group of black level data, and a long axis connecting the farthest point and nearest point from the center of gravity to the outside of the existence area and the center of gravity. and a step of determining the front and back sides of the component based on the direction in which the other is viewed from one of the long and short axes, and a step of determining the gripping position of the component based on the center of gravity position according to the result of the front and back determination. A method characterized by setting.