JPH01257206A - Position recognition apparatus - Google Patents

Abstract

PURPOSE:To enable recognition of a position of an object to be recognized at a high accuracy, by irradiating the object to be recognized with slit lights orthogonal to each other to determine the position of the center of the object being recognized from an image data obtained by taking the slit lights. CONSTITUTION:Slit lights 3a and 4a from X- and Y-axis illuminators 3 and 4 are reflected with galvanomirrors 5 and 6 and irradiated on a chip part 2 to be taken with a camera 7 above a circuit board 1. A cumulative distribution of a binary level is determined along the length of the slit lights with a first cumulative distribution processing means 13a for slit light part within an image data obtained with the device 7. Edge positions of the slit lights are determined by a window preparation means 14 from the resulting first cumulative distribution data. From the edge position thus obtained, a second window is prepared to determine an cumulative distribution of a binary level across the width of the slit lights by a second cumulative distribution processing means 13b. Moreover, edge positions of the object to be recognized are determined from the resulting second cumulative distribution data by a position computing means 5 to obtain the center position of the object being recognized from the edge positions thus obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a position recognition device suitable for recognizing the position of a chip component or the like mounted on a circuit board.

(Prior Art) Electrical devices such as home appliances and OA equipment are becoming smaller, and along with this, the circuit boards used in each home appliance are also becoming smaller. For example, instead of circuit boards with lead wires, circuit boards to which small chipped resistors, capacitors, etc. can be attached are now being used. Due to the miniaturization of such mounting components, high-density mounting is required for mounting them on circuit boards.

To attach such chip components to a circuit board, a mounting device automatically temporarily attaches the chip components to a circuit board on which a predetermined wiring pattern has been formed in advance, and then soldering is performed by a device or the like. It's finished. but,
Devices attached to circuit boards often fall off or become misaligned. If such a thing is detected after soldering, a lot of effort will have to be spent on its correction.

Therefore, it is necessary to inspect the chip components of the circuit board for falling off, misalignment, etc. before soldering.

Therefore, this inspection was performed visually by workers, which required a large number of workers. Furthermore, visual inspections often result in inspection errors because multiple chip components are mounted on a complex circuit board, and the work requires detailed inspections all day long, which causes eye strain and poses health management problems. was there.

In response, there is a technology that automates the inspection of circuit boards.
This involves capturing an image of a circuit board using an imaging device, processing the resulting image data to recognize the mounting position of a chip component, etc., and detecting the dropout or misalignment of a chip component from this recognition result. It is a technology that However, with this technology, wiring patterns on circuit boards, printed characters,
Misjudgments often occur because a target chip component or the like is searched for or extracted from a mixture of multicolored and multishaped components and inspected. For this reason, it is still insufficient in terms of inspection accuracy and reliability, and especially when the target chip component or the like has a shape other than a normal rectangular parallelepiped, the inspection accuracy and reliability are insufficient.

(Problems to be Solved by the Invention) As described above, although there is a technology that automates the inspection of circuit boards, the technology is affected by complex shapes, colors, etc., and the inspection accuracy is low and reliability is poor.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a position recognition device that can recognize the position of a target object with high precision without being affected by complicated shapes, colors, etc.

[Structure of the Invention] (Means for Solving the Problems) The present invention irradiates the object with slit lights perpendicular to each other and images the slit lights. In a position recognition device that recognizes the center position, a first window is set for each slit light portion in the image data, and the integrated distribution of the binarization level is calculated in the length direction of each slit light within these first windows. a first cumulative distribution processing means for calculating the
The edge position of each slit light is determined from the first integrated distribution data obtained by the integrated distribution processing means, and a second window having a width equal to or narrower than the width of each slit light is created from these edge positions. A window creation means, and each second window created by this window creation means is set in each slit light portion in the image data, and the binarization level is integrated in the width direction of each slit light within these second windows. a second cumulative distribution processing means for calculating the distribution; and a second cumulative distribution processing means for calculating the distribution.
The present invention is a position recognition device that attempts to achieve the above object by including a position calculation means for determining each edge position of the object to be recognized from integrated distribution data and calculating the center position of the object from these edge positions.

(Function) By having such a means, the first integrated distribution processing means sets the first window for each slit light portion in the image data and divides the binarization level in the length direction of the slit light. Find the cumulative distribution. Then, the window creation means determines the edge position of each slit light from the obtained first integrated distribution data and creates a second window having a width equal to or narrower than the width of each slit light from these edge positions. create. Then, the second integrated distribution processing means sets these second windows to each slit light portion in the image data and calculates the integrated distribution of the binarization level in the width direction of each slit light, and furthermore, the position calculation means From this second cumulative distribution data, each edge position of the object to be recognized is determined, and from these edge positions, the center position of the object to be recognized is determined. (Example) Hereinafter, an example of the present invention will be described with reference to the drawings. do.

FIG. 1 is a block diagram of a position recognition device. A chip component 2, which is an object to be recognized, is mounted on the circuit board 1. Now, above the circuit board 1 are an X-axis slit illumination device 3 and a Y-axis slit illumination device 3
Axial slit illumination devices 4 are disposed, and galvano mirrors 5 and 6 are disposed on the slit optical paths of these X-axis and Y-axis slit illumination devices 3 and 4, respectively.

Therefore, each slit light beam 3a, 4a emitted from the X-axis and Y-axis illumination device 3.4 is reflected by the galvanometer mirrors 5, 6, respectively.
The light is reflected and irradiated onto the chip component 2. Further, an imaging device 7 is arranged above the circuit board 1,
The output image signal is binarized by a binarization circuit 8 and stored in an image memory 9 as image data.

By the way, the galvano mirrors 5 and 6 each receive rotation angle data MXD,
The reflection direction of each slit light beam 3a, 4a is varied by rotating according to a drive control signal based on MYD, thereby making each slit light beam 3a, 4a orthogonal to each other at the mounting reference position 0 (ox, oy) of the chip component 2. Irradiation is controlled so that Here, this rotation angle data MX
D and MYD are the X-axis direction and Y direction of the galvanometer mirrors 5 and 6.
Each scanning resolution in the axial direction is Mx, My, the height data of the chip component 2 is H1, the thickness data of the circuit board 1 is T1, the X of the height data H and thickness data T at each scanning position of each galvano mirror 5, 6 The correction values in the axis and Y-axis directions are Kx, Ky
, further, if the center position of the field of view of the imaging device 7 is l'x, noy), then M x D - (Ox -1! x ) / M x
+ H+ T + K x MYD= (Oy, 1'
)')/My+H10T0Ky.

Now, 11 is an image processing device, and this image processing device 11 has a function of recognizing the center position of the chip component 2 from the image data stored in the image memory 9.

Specifically, the peripheral distribution processing unit 13 has the functions of a peripheral distribution processing unit 13, a window creation unit 14, and a position calculation unit 15, which are each controlled by the main control unit 12. The peripheral distribution processing units 13 are the first and twenty-first! i calculation distribution processing means 13g, 1
3b, the first integrated distribution processing means 13g sets first windows Wx, Wy for each slit light portion in the image data, and calculates the length of each slit light within these first windows Wxl, Wyl. The second integrated distribution processing means 13b has a function of obtaining an integrated distribution of binarization levels in the horizontal direction, and the second integrated distribution processing means 13b processes each second window Wx2.
It has a function of setting Ky2 in each slit light portion in the image data and obtaining the cumulative distribution of the binarization level in the width direction of each slit light within these second windows. The window creation means 14 calculates the edge position of each slit light from the first integrated distribution data obtained by the first integrated distribution processing means 13a, and creates a second window W having a width equal to the width of each slit light from these edge positions.
x2. It has the function of creating Ky2. Then, the position calculation means 15 is the m2 integrated distribution processing means 13b.
This device has a function of determining the edge positions of the chip component 2 from the second integrated distribution data determined in step 2, and determining the center position of the chip component 2 from these edge positions. The main control means 12 controls the operation of each of these means according to the recognition flowchart program shown in FIG.
It has a function of sending a timing signal to the timing circuit 17 to determine the operation timing with the value converting circuit 8, and also sending an operation command to the light source power source 18 for operating the X-axis and Y-axis slit illumination devices 3.4, respectively. ing.

Next, the operation of the apparatus configured as described above will be explained according to the recognition flowchart shown in FIG. Step S
1, the main control means 12 sends an operation command to the light source power supply 18. As a result, the X-axis and Y-axis slit illumination devices 3.4 respectively emit slit lights 3a and 4a. At the same time, the main control section 12 sends the rotation angle data MXD and MYD to the galvano mirror control circuit 10, whereby the galvano mirror control circuit 10 rotates each of the galvano mirrors 5 and 6 according to these rotation angle data MXD and MYD. Drive. Thus, the slit lights 3a and 4a are irradiated at the mounting reference position 0 (ox, oy) on the chip component 2 so as to be perpendicular to each other.

When each slit light beam 3a, 4a is irradiated onto the mount reference position 0 in this way, the process moves to step s2 and the main control unit 12
sends an operation start command to the timing circuit 17. Thereby, the imaging device 7 images a picture in which the chip component 2 is within its field of view and outputs the image signal. This image signal is binarized by a binarization circuit 8 at a predetermined binarization setting level, sent to an image memory 9, and stored in this image memory 9 as image data.

Once the image data is stored in this way, the next step s
3, the main control means 12 issues an operation command to the peripheral distribution processing section 13. Now, when the peripheral distribution processing unit 13 receives an operation command, first the first integrated distribution processing unit 13a receives the image data stored in the image memory 9 and processes the portions of each slit light 3a-, 4a- of this image data. The first windows Wxl and Wyl are respectively set as shown in FIG.

Note that the sizes of these first windows Wxl and Wyl are set so as to include the respective slit lights 3a and 4a. Further, 2' is an image of the chip component 2. When each window Wxl, Wyl is set in this way, the first cumulative distribution processing means 13a calculates the cumulative distribution of the binarization level within each window Wxl, Wyl in step s4. That is, window W X 1
To explain, the binarization level is integrated in the length direction of the slit light 3a- within this window WXI,
Accumulated distribution data Qxl, which is the result of this accumulation, is obtained. On the other hand, the binarization levels are similarly integrated for window Wy1, and integrated distribution data Qyl, which is the integration result, is obtained. This integrated distribution data Qyl is then passed to the window creation means 14, and this window creation means 14
The process moves to step S5 and these integrated distribution data Qxl,
The edge position of each slit light 38'', 4a-, that is, the slit light 3a, is determined using the threshold value L1 for Qyl.
For -, yl and y2 are obtained, and for the slit light 4a-, xi and x2 are obtained, respectively. In addition, the main control means 1
2 are these edge positions X1. Center position XS in the length direction of each slit light from X2, yLy2.

The value s

Next, proceeding to step s6, the window creation means 14 calculates the 8 widths Fx and Fy of each slit beam 3a-, 4a- from these edge positions yl, y2, and xl, x2, Fy -l yl-y21 F X = l xi Calculate and find −x2 l. Then, the width ry second window Wx2 of the slit light 3a'' is created, and the width F of the slit light 4a- is created.
A second window Wy2 is created from x. Note that at this time, the length of each window WX2°Wy2 is the same as that of the first window Wx1+Wy1. Then, these second windows Wx2. Wy2 is sent to the second ffl calculation distribution processing means 13b by the command of the main control section 12, respectively.

Now, this second cumulative distribution processing means 13b processes each second window W! 2. When receiving Wy2, as shown in FIG. 4, the second window Wx2 is set in the length direction of the slit light 3a=, and the second slit light Wy2 is set in the length direction of the slit light 4a-. . In addition, in FIG. 4, each second window Wx2. 8 widths of Wy2 and each slit light 3a'.

4a- does not match the width, but this is for the sake of clarity in the illustration. Then, the process moves to step s7, and the second integrated distribution processing means 13b processes each window Wx2. W
Find the cumulative distribution of binarization levels at y2. In addition,
The method of obtaining this integrated distribution is similar to the processing method of the first integrated distribution processing means 13a, but in this means 13b, integration is performed in the width direction of each slit beam 3a-, 4a-. Therefore, to explain the second window Wy2, the binarization level is integrated in the width direction of the slit light 4a- in this second window Wy2, and the integrated distribution data Qx
Find 2. Similarly, in the second window Wx2, the binarization levels are integrated in the width direction of the slit light 3a- to obtain integrated distribution data Qy2. Each integrated distribution data Qx2. Qy2 is calculated by the position calculation means 15 according to the command from the main control means 12.
passed to.

This position calculating means 15 uses the threshold value L2 in step s8 to calculate the edge positions ya, y on the top surface of the chip component 2.
4 and x3. Find x4, and further calculate these edge positions y
3. y4 and x3. The center position Oc (Xc, Yc) of the chip component 2 is determined from x4. That is, the center position Oc (Xc, Yc) is calculated from Xc = (x3+x4) / 2 Yc trout (y3 + y4) /2.

By the way, due to the above action, the center position O of the chip component 2
c (Xc, Yc) is found, but this center position @O
c indicates the position where the chip component 2 is not rotating. Therefore, in order to determine whether the chip component 2 is rotating, the main control means 1 determines whether the center position has been recognized twice in step s9, and if it has not been recognized twice,
The center position Oc of the chip component 2 that has just been recognized is the reference position Oc.
, and executes steps 5l-s8 again to perform position recognition. Then, in step sll, the main control means 12 determines the difference between the reference position Oe and the center position of the chip component 2 whose position has been recognized this time, and compares this difference with a predetermined value d. As a result of this comparison, if the difference is smaller than the predetermined value d, the main control means 12 recognizes the center position of the chip component 2 whose position has been recognized this time as the correct center position of the chip component 2. However, if the difference is larger than the predetermined value d, step s1
2, the reference position Oc is changed to the center position of the chip component 2, and in the next step s13, this reference position O is changed to the center position of the chip component 2.
Correct c. In other words, the corrected new reference position (o
x” + OY−) is ox= −Xc + (ox−Xs )oy−−Yc
+ (oy-Ys). Therefore, when returning to step sl and irradiating each slit light 3a, 4a, these slit lights 3ar
4a is this reference position (OX-).

oy-) onto the chip component 2. Then, if the center position of the chip component 2 is recognized again and the difference is larger than the predetermined value d, a new reference position (OX'', oy') is determined again.

In this way, in the above embodiment, the first window is set, the cumulative distribution of the binarization level within this window is determined, and the width of each slit light is determined from this data and is equal to the width of the slit light. Create a second window and this second window
The window is further set to obtain the integrated distribution data of the binarized level, and from this data, each edge position of the chip component 2 is determined and its center position is determined. each slit light 3a
, 4a can be extracted, and the edge position of the chip component 2 can be reliably detected without being influenced by the shape or color of other components, and the center position of the chip component 2 can be detected. In other words, Fig. 5 (a
) When a chip component 20 as shown in (b) is mounted, when the top surface of this chip component 20 is irradiated with slit light 21, this slit light 21 will not be irradiated onto the top surface 22 of the chip component 20. Of course, the shoulder portion of the lead wire 23 is also irradiated. Therefore, since there is not much difference between the height position of the upper surface 22 of the chip component 20 and the height position of the shoulder portion of the lead wire 23, the irradiated slit light 21 is recognized as being continuous. However, if the device of the present invention is applied, the second window W2 will include only the slit light 21 irradiated onto the top surface of the chip component 2, as shown in FIG. The center position of the chip component 20 can be determined by determining the edge position of the chip component 20. In addition, it is possible to eliminate not only the influence of the shoulder portion of the lead wire 23 but also the influence of the slit light irradiated onto the mold joint portion of the chip component 20.

Furthermore, when the difference between the reference position and the center position becomes more than a predetermined value d, the reference position is corrected and each slit light beam 3a, 4a is irradiated. Location can be recognized without being affected.

Note that the present invention is not limited to the above-mentioned embodiment, and may be modified without departing from the spirit thereof.For example, once the second window is set, the center position of the other chip components can be changed. When recognizing, if this second window is moved to the reference position of the target chip component, the position can be recognized efficiently. Further, even if the width of the second window is set narrower than the width of the slit light, the edge position of the chip component 2 can be determined.

[Effects of the Invention] As described in detail above, according to the present invention, it is possible to provide a position recognition device that can recognize the position of a target object with high precision without being influenced by a complicated shape or its color.

[Brief explanation of the drawing]

1 to 6 are diagrams for explaining one embodiment of the position recognition device according to the present invention, in which FIG. 1 is a configuration diagram, FIG. 2 is a recognition flowchart, and FIG. 3 is a first window FIG. 4 is a schematic diagram for explaining the operation of the second window, and FIGS. 5 and 6 are diagrams for explaining an example of the position recognition operation. DESCRIPTION OF SYMBOLS 1... Circuit board, 2... Chip component, 3... X-axis slit lighting device, 4... Y-axis slit lighting device, 5
゜6... Galvano mirror 17... Imaging device, 8...
- Binarization circuit, 9... Image memory, 11... Image processing device, 12... Main control means, 13... Peripheral distribution processing section, 13a... First integrated distribution processing means, 13b・・・
- Second integration distribution processing means, 14...window creation means, 15...position calculation means. Applicant's agent Patent attorney Takehiko Suzue Figure 3 Figure 4 (a) Figure 5 Figure 6 (b) Figure

Claims (1)

[Claims] In a position recognition device that recognizes the center position of the object from image data obtained by irradiating each slit light orthogonal to the object and imaging these slit lights, each of the slits in the image data a first cumulative distribution processing means that sets a first window for each light portion and calculates a cumulative distribution of binarization levels in the length direction of each of the slit lights within these first windows; The edge positions of each of the slit lights are determined from the first integrated distribution data obtained by the processing means, and a second window having a width equal to or narrower than the width of each of the slit lights is created from these edge positions. a window creation means, and each second window created by the window creation means is set in each of the slit light portions in the image data, and binarization is performed in the width direction of each of the slit lights within these second windows. a second cumulative distribution processing means for calculating the cumulative distribution of the level; and a second cumulative distribution processing means for determining the respective edge positions of the object to be recognized from the second cumulative distribution data obtained by the second cumulative distribution processing means, and from these edge positions. 1. A position recognition device comprising: position calculation means for determining a center position.