KR101836136B1 - Center of hole position finder unit and inspector with thereof - Google Patents

Abstract

The present invention relates to a through-hole center measuring unit which is used to test whether a product is manufactured as designed or not, and a test device using the same. The through-hole center measuring unit measures a through-hole center of a product to be tested which has a through-hole, and comprises: a test jig on which the product to be tested is mounted; a storage unit which stores design data of the product to be tested and location data of the test jig; a camera; a camera moving unit which relatively moves the camera with respect to the test jig; a control unit which controls the camera and the camera moving unit to capture three or more spots of the circumference of the through-hole of the product to be tested on the basis of the design data and the location data; and a calculation unit which calculates the real center of the through-hole through capturing images of the product to be tested captured by the camera.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a center-

The present invention relates to a through-hole center measuring unit used for checking whether a product is manufactured as designed, and an inspection apparatus using the same.

If a product is not manufactured as designed, the performance of the product may deteriorate. Especially, in the case of a product made up of a large number of parts such as an automobile, the assembling of the finished product may not be possible due to accumulation of errors of each part. In order to check the product is essential.

The inspection through the naked eye does not require a separate device but the accuracy is poor and the inspector can easily be fatigued. Also, the 'automatic measuring device for measuring the hole displacement using the contact type displacement sensor' of the registered patent 10-0803657 The device can automatically inspect the product, but subsequent contact with the product may deform the contact portion of the device and reduce the accuracy of the inspection.

Another method of inspecting a product is a method of acquiring and analyzing a three-dimensional image of a product using a camera, such as a three-dimensional model generation and defect analysis method using a camera and a laser scan, in Japanese Patent Laid-Open No. 10-1604037. It is possible to easily perform inspection without causing deformation of the inspection apparatus or the parts to be inspected, but the accuracy of the inspection may be deteriorated because the analysis of the image is not accurate.

KR 10-1604037 B1

It is an object of the present invention to provide a through hole centering unit capable of precisely inspecting a product and an inspection apparatus using the same.

According to a preferred embodiment of the present invention, there is provided a unit for measuring a center of a through hole of a product to be inspected having a through hole, the unit comprising: a test jig on which a product to be inspected is seated; A storage unit for storing design data of a product to be inspected and position data of the inspection jig; camera; A camera moving unit capable of moving the camera relative to the inspection jig; A control unit for controlling the camera and the camera moving unit to photograph three or more positions of a through hole circumference of a product to be inspected based on the design data and the position data; And a calculation unit for calculating an actual center of the through hole through photographed images of a product to be inspected photographed by the camera.

Wherein the controller controls the camera to photograph three or more positions of the through-hole circumferences in a state in which the photographing angle of the camera is at a predetermined angle with the axial direction of the through-hole, and the calculating unit corrects the photographing images according to a predetermined angle, The center can be calculated.

The calculation unit may calculate a curvature radius value of an arc in each of the photographing images and calculate an actual center by averaging the center values of the arcs having the curvature radius value in the design data and the tolerance range.

The calculation unit can calculate the actual center of the through hole by obtaining a circle passing through at least three points on the arc of the captured images.

The inspection sheet may include a reflection plate at a position below the through hole of the product to be inspected.

The test specimen includes a conical conical portion, a cylindrical neck portion continuous to the lower surface of the conical portion and having a diameter smaller than the diameter of the lower surface of the conical portion, and a cylindrical portion continuous to the lower surface of the neck portion and having a diameter larger than the diameter of the conical portion And an origin adjustment pin formed of a base end portion of the base.

According to another embodiment of the present invention, there is provided an apparatus for inspecting the quality of a product to be inspected by comparing design data of the product to be inspected having three or more through holes with actual data, The through-hole center measuring unit for measuring the through-hole; Laser irradiator; The laser irradiator irradiates the surface of the circumferential portion of each of the through holes of the inspection target product with the laser beam while moving based on the design data and the position data, and the camera photographs an image of the laser beam irradiated on the surface of the inspection target product A second control unit for controlling the second control unit; A second calculation unit for calculating an actual distance between the surface of the through hole and the laser irradiator through the photographed image of the laser beam photographed by the camera; And a discrimination unit for comparing the design data of the inspection object product with the actual data obtained by the calculation unit and the second calculation unit to discriminate the quality of the product to be inspected.

Wherein the discrimination unit is arranged to match the center of one through hole among predetermined three through holes on the design data of the product to be inspected and the actual center of one through hole among the predetermined three through holes on the actual data, The process of aligning the direction from the center of the one through hole to the center of the other through hole and the direction from the actual center of the one through hole among the three predetermined through holes on the actual data to the actual center of the remaining through hole among the three predetermined through holes After roughing, the design data of the product to be inspected can be compared with the actual data.

The apparatus further includes a laser beam reflector, and the second controller can control the laser irradiator to irradiate the laser beam through the laser beam reflector.

The inspection apparatus according to the present invention can accurately calculate the actual position of the through hole of the inspection target product, so that the quality of the inspection inspection product can be accurately determined.

In addition, the accuracy of the quality discrimination can be further improved by correcting the errors arising from the inaccuracy of the position or angle on which the inspection object is placed.

1 is a conceptual explanatory view of a testing apparatus to which a through-hole center measuring unit according to the present invention is applied.
Fig. 2 is an explanatory diagram of an origin adjustment pin of the through-hole drill measurement unit. Fig.
FIG. 3 is an explanatory view of a method of calculating the center of the through-hole by the through-hole-center measuring unit. FIG.
Fig. 4 is an explanatory view of another method of calculating the center of the through-hole with the through-hole-center measuring unit. Fig.
FIG. 5 is an explanatory view of a case where the camera photographing angle of the through-hole center-of-gravity measuring unit is oblique with respect to the axial direction of the through-hole.
FIG. 6 is an explanatory view of a laser irradiation device of the inspection apparatus. FIG.
FIG. 7 is an explanatory view of a case where the determination unit of the inspection apparatus undergoes a coordinate correction process. FIG.

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

The present invention relates to a through-hole center measuring unit and an inspection apparatus using the same, and more particularly, it relates to a through-hole center measuring unit which photographs a product to be inspected using a camera, calculates actual data of the inspection target product, Can be confirmed.

In order to perform the inspection through the inspection apparatus according to the present invention, it is preferable that the product to be inspected has at least three through holes.

Fig. 1 is a conceptual explanatory view of a testing apparatus 1 to which a through-hole center measuring unit according to the present invention is applied.

The through hole center measuring unit according to the present invention serves to measure the actual center of each through hole of the product to be inspected in the inspection apparatus 1. The through hole center measuring unit according to the present invention is provided with an inspection jig 11, a storage unit 12, A camera section 14, a control section 15, and a calculation section 16.

The inspection jig (11) has an actual inspection target product placed thereon. The inspection target product S placed on the inspection jig 11 is fixed in a fixed position without moving during the measurement operation.

The design data of the product S to be inspected and the position data of the inspection jig 11 are stored in the storage unit 12. Design data can be obtained by photographing master products that have been manufactured correctly.

The camera 13 is attached to the camera earthed portion 14 and moves together as the camera ear portion 14 moves relative to the inspection jig 11. [ The robot 14 can be used as a robot.

The control unit 15 causes the camera moving unit 14 to move based on the inspection jig 11 and the camera 13 photographs the through hole H of the product to be inspected on the inspection jig 11 Since the design data of the product to be inspected and the position data of the inspection jig 11 are stored in the storage unit 12, it is possible to guide the camera id 14 to the through hole position of the product to be inspected. The camera 13 is controlled so as to photograph three or more positions of the through-hole circumferences among the through-hole portions of the product to be inspected.

The calculation unit 16 recognizes the boundary between the surface of the inspection target product around the through hole and the space in the through hole in the photographed images I photographed by the camera 13, The actual center RM of the through hole is calculated by obtaining a circle RC including the boundary of the through hole. The boundary of the circular arc shape is enlarged on the photographed image I obtained by photographing a part of the circumference of the through hole and it can be recognized clearly. Since such a photographed image is obtained at a plurality of positions in the circumference of the through hole, (RM) can be accurately calculated.

The inspection jig 11 may further include an origin adjustment pin 11b. Fig. 2 is an explanatory view thereof.

The origin adjusting pin 11b has a cylindrical conical portion c and a cylindrical neck portion n continuous to the lower surface of the conical portion c and having a smaller diameter than the lower surface of the conical portion c, And a proximal end portion (b) continuous to the lower surface of the neck portion (n) and having a diameter larger than the diameter of the conical portion (c).

2 (a), the light incident on the oblique surface of the conical portion c is scattered. However, when the origin point adjusting pin 11b is photographed by the camera 13, The light incident on the upper surface is reflected as it is and is photographed by the camera 13. The image of the origin point adjusting pin 11b photographed by the camera 13 shows that the conical portion c is dark and the proximal portion b is bright as shown in FIG. It is possible to precisely match the reference portion of the design data with the conical portion c as the reference point of the inspection jig 11. [ Thus, the camera east portion 14 and the camera 13 can be moved to the correct position of the inspection jig 11 which needs to be photographed by the design data.

It is preferable that the origin adjustment pins 11b are formed on three or more places on the inspection jig 11 in order to more precisely match the position data of the design data and the inspection jig.

In order to prevent damage to the origin adjusting pin 11b by placing the inspection target product on the inspection jig 11, as shown in Fig. 2 (a), a space 11c And the origin point adjusting pin 11b can be arranged in the inside thereof.

The calculation unit 16 can calculate the actual center RM of the through hole H in the following manner.

The calculation unit 16 first obtains the radius of curvature of the arc in the boundary between the surface of the product to be inspected and the space in the through hole around the through hole, that is, the arc in each shot image. Through the arc, the radius and the center of the circle including the arc can be known. Since the arc of each of the images is a part of the circumference of the through hole, the center of the through hole can be recognized through the arc.

However, although the captured images are a set of a number of pixels and represent a part of the through-hole circumference much like the actual one, it is not exactly the same as the actual one. Therefore, the allowable error range is determined, and the values outside the tolerance range are excluded based on the design data among the calculated radius of curvature values, and only the values within the tolerance range are used to obtain the actual center of the through hole.

The center value of each of the arcs whose radius of curvature is within the tolerance range is averaged to obtain the actual center of the through-hole.

FIG. 3 is an explanatory view of a case where the center of a through hole is obtained through three arcs (a1, a2, a3) whose curvature radius value is within an allowable error range by way of example. The three circular arcs a1, a2 and a3 are obtained through respective photographed images in which the camera 13 is controlled by the control unit 15 and photographed around the through hole. Since the relative positions of the three arcs a1, a2 and a3 are known, As shown in Fig.

A value obtained by averaging the center values of the arcs a1, a2 and a3 is regarded as the actual center (RM) of the through hole. For example, when the centers of three arcs a1, a2 and a3 are (0, 3), (3, 0) and (6, 0) Becomes the center (RM).

The calculation unit 16 may calculate the actual center of the through hole by obtaining a circle passing through a total of three or more points on the arc of the captured images. FIG. 4 is an explanatory view thereof.

Even if the position of the through hole (DC) on the design data does not coincide with the position of the actual through hole RC because the design data of the product to be inspected and the actual data of the product to be inspected do not match due to an error of the actual inspection target product, The camera 13 is controlled by the control unit 15 and the perimeter of the through hole is photographed so that the relative position between the photographed images can be known as shown in Fig. 4 (a) ). For reference, in FIG. 4 (a), it can be seen that the four captured images having an interval of about 90 degrees on the periphery of the through hole are arranged.

As shown in (b) of FIG. 3, arbitrary three points (P1, P2) on the arcs (a1, a2, a3) , P3), a circle RC passing through these points can be obtained, and the center of the circle becomes the actual center RM of the through hole H.

It is preferable that the three points on the circular arc are positioned so as to be as large as possible so that the accuracy of calculation is not deteriorated by a foreign material adhered to the periphery of the through hole.

In order to reduce the error between the center of the through-hole calculated on the shot image and the actual center (RM) of the through-hole, an arbitrary point of more than three in the arc of the captured images is determined and all three points After finding the circle, you can calculate the center of the through hole by averaging the center values of these circles. For example, a first circle, a first circle passing through first, second, and third points, a second circle passing through first, second, and fourth points, , A third circle passing through four points and a fourth circle passing through the second, third and fourth points are obtained, and the centers of the first to fourth circles are averaged to calculate the center of the through hole.

The control unit 15 can control to photograph three or more places of the through hole circumferences in a state in which the photographing angle of the camera 13 forms a predetermined angle alpha with the axial direction of the through hole H. [ Fig. 5 is an explanatory view of this case.

5 (a), when the through hole H is photographed while the camera 13 is positioned at an oblique position with respect to the axial direction of the through hole H, Not only the upper surface UF of the product to be inspected but also the inner surface IF of the through hole H are exposed. Light incident on the inner surface IF of the through hole is reflected and photographed by the camera 13, The light incident on the space part of the through-hole H is absorbed under the product to be inspected, and the through-hole H, which is brightly represented as shown in FIG. 5 (b) And is clearly distinguished from the space portion of the hole. Therefore, it is possible to clearly recognize the arc shape boundary of the through hole H in the photographed image I.

However, when the camera 13 photographs the through-hole H in an oblique state with respect to the axial direction of the through-hole H, the through-hole H in the captured image I appears as an ellipse The calculation unit 16 must correct the photographed images I to a predetermined angle?. For example, an image photographed in a state where the axial direction of the through hole H is placed on the Z axis and the camera is changed on the X axis so that the camera and the Z axis form a predetermined angle, (α) so that the ellipse is a circle.

After correcting the photographed image I, the actual center RM of the through-hole H is obtained in the same manner as shown in Figs.

The inspection jig 11 may be provided with a reflection plate 11a at a position under the through hole of the product to be inspected.

Since the reflection plate 11a reflects light, the surface of the product to be inspected around the through hole that absorbs light on the photographed image is more clearly contrasted with the surface of the product to be inspected, And the boundary of the circular arc that is formed becomes clear.

Hereinafter, the inspection apparatus 1 using the through-hole centering unit will be described.

The inspection apparatus 1 includes the through hole center measurement unit, the laser irradiation unit 20, the second control unit 30, the second calculation unit 40, and the determination unit 50.

The through-hole-center measuring unit measures the center of each through-hole of the product to be inspected.

The laser irradiator 20 serves to irradiate the surface of the product to be inspected with a laser beam. The laser irradiator 20 is controlled by the second control unit 30 to detect the design data of the product to be inspected stored in the storage unit 12, The laser beam is irradiated to the surface of the circumferential portion of each through hole of the inspection target product while moving on the basis of the inspection jig 11 according to the position data.

The second control unit 30 also controls the camera 13 to shoot an image of the laser beam irradiated on the surface of the product to be inspected. At this time, it is natural that the camera section 14 moves and the camera 13 is moved.

The second calculation unit 40 calculates the actual distance between the laser irradiator 20 and the surface of the peripheral portion of the through hole of the product to be inspected through the picked-up image of the laser beam photographed by the camera 13. [ 6, when the laser beam L is obliquely irradiated on the surface F of the product to be inspected, the distance between the surface F of the product to be inspected and the laser irradiator 20, The position of the laser beam on the surface F of the product is changed, so that the actual distance between the surface of the product to be inspected and the laser irradiator 20 can be calculated.

The laser irradiator 20 may be controlled to directly irradiate the surface F of the product to be inspected with the laser beam L as shown in Figure 6 (a) The inspection apparatus 1 according to the present invention may further include a laser beam reflector 60 and be controlled to irradiate the laser beam L through the laser beam reflector 60. [

When the inspection apparatus according to the present invention further comprises a laser beam reflector 60, the angle of the laser beam reflector 60 or the angle of the laser beam L incident on the laser beam reflector 60 is adjusted, It is possible to irradiate the laser beam L to a desired position on the surface of the product to be inspected without greatly affecting the surface distance of the product to be inspected.

When the surface of the product to be inspected has a property of reflecting the laser beam, the actual distance between the surface of the product to be inspected and the laser irradiator 20 is measured by measuring the time when the laser beam irradiated to the surface of the product to be inspected returns It can also be obtained.

The actual through hole center value of the product to be inspected placed on the inspection jig 11 is obtained by the calculation unit 16 and the second calculation unit 40 calculates the product of the surface of the product through- ), That is, the actual data of the product to be inspected has been obtained, so that the determination unit 50 can compare the actual data values with the design data of the product to be inspected. When the actual data value of the inspection target product is within the design data value and error range, it is judged that the inspection target product is usable.

For the accuracy of the quality discrimination for the product to be inspected, the center value of the three or more through holes dispersed on the product to be inspected and the distance to the laser emitter 20 are obtained and compared with the design data.

The laser irradiator 20 can be attached to the robot in the same manner as the camera 13 and can move with respect to the inspection jig 11.

After the coordinate correction process, the determination unit 50 can determine the quality of the inspection target product by comparing the design data of the inspection target product with the actual data. Fig. 7 is an explanatory view thereof.

The difference between the actual data value of the product to be inspected and the design data value may occur because the product to be inspected is not manufactured as designed. However, as shown in FIG. 7A, (DG) of the design data and the coordinates (RG) of the actual data because there is an error between the coordinates (DG) of the design data and the coordinates (RG) of the actual data. The coordinate correction process is performed to correct an error arising from the inaccuracy of the position or angle on which the inspection object is placed.

The coordinate correcting process is a process of correcting the coordinates of the center of the one through-hole DH1 among the three predetermined through-holes DH1, DH2 and DH3 and the predetermined three through- Through hole (RH1) in the first through-hole (RH3); And the directions DA1 and DA2 from the center of the one through hole DH1 to the center of the remaining through holes DH2 and DH3 among predetermined three through holes on the design data of the product to be inspected and predetermined three (RA1, RA2) from the center of the through hole (RH1) to the center of the remaining through holes (RH2, RH3) in the through hole.

Even if the design data of the product to be inspected and the actual data are different, the positions of at least one through-holes DH1 and RH1 can be matched as shown in Fig. 7 (b) (DO) of the design data coincides with the origin (RO) of the actual data coordinates.

7 (c), the coordinate axes of the design data coincide with the coordinate axes of the actual data.

Thus, it is possible to prevent the accuracy of the discrimination on the inspection target product from being deteriorated due to the inaccuracy of the position or the angle on which the inspection target product is placed.

While the invention has been shown and described with reference to certain preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. And thus fall within the scope of the present invention.

1: inspection device 11: inspection jig
11a: Reflector 11b: Origin adjustment pin
12: storage unit 13: camera
14: east end of the camera 15:
16: Calculation section 20: Laser irradiation device
30: second control unit 40: second calculation unit
50: discrimination unit 60: laser beam reflector

Claims (9)

A unit for measuring a center of a through hole of a product to be inspected having a through hole,
A test jig on which the product to be inspected is seated;
A storage unit for storing design data of a product to be inspected and position data of the inspection jig;
camera;
A camera moving unit capable of moving the camera relative to the inspection jig;
A control unit for controlling the camera and the camera moving unit to photograph three or more positions of a through hole circumference of a product to be inspected based on the design data and the position data; And
And a calculation unit for calculating an actual center of the through hole through photographed images of the inspection target product photographed by the camera,
Wherein the calculation unit calculates the actual center of the through-hole by obtaining a circle passing through at least three points on the arc of the captured images.
The method according to claim 1,
The control unit controls to shoot at three or more positions of the through-hole circumference in a state in which the photographing angle of the camera is at a predetermined angle with the axial direction of the through-hole,
Wherein the calculation unit calculates the actual center of the through hole after correcting the shot images according to a predetermined angle.
The method according to claim 1,
Wherein the calculation unit obtains a curvature radius value of an arc in each of the shot images and calculates an actual center by averaging the center values of the arcs whose design values and the radius of curvature are within a tolerance range. unit.
delete The method according to claim 1,
Wherein the inspection sheet includes a reflection plate at a position below the through hole of the product to be inspected.
The method according to claim 1,
The inspecting paper,
A cylindrical neck portion continuous to the lower surface of the conical portion and having a diameter smaller than the diameter of the lower surface of the conical portion, and a cylindrical base portion continuous to the lower surface of the neck portion and having a diameter larger than the diameter of the conical portion, And an origin point adjusting pin which is provided on the center of the through hole.
An apparatus for inspecting quality of a product to be inspected by comparing design data of a product to be inspected having three or more through holes with actual data,
A through-hole center measuring unit according to any one of claims 1 to 3 and 5 to 6 for measuring the center of each through-hole of the product to be inspected;
Laser irradiator;
The laser irradiator irradiates the surface of the circumferential portion of each of the through holes of the inspection target product with the laser beam while moving based on the design data and the position data, and the camera photographs an image of the laser beam irradiated on the surface of the inspection target product A second control unit for controlling the second control unit;
A second calculation unit for calculating an actual distance between the surface of the through hole and the laser irradiator through the photographed image of the laser beam photographed by the camera; And
And a determination unit for comparing the design data of the inspection target product with the actual data obtained by the calculation unit and the second calculation unit to determine the quality of the product to be inspected,
Wherein,
The center of one through hole among the predetermined three through holes on the design data of the inspection target product and the actual center of one through hole among the predetermined three through holes on the actual data are made to coincide with each other,
The direction of the center of the through hole from the center of one of the three predetermined through holes to the center of the other through hole among the predetermined three through holes on the actual data and the actual center of the remaining through hole And comparing the design data of the product to be inspected with the actual data.
delete 8. The method of claim 7,
Further comprising a laser beam reflector,
Wherein the second control unit controls the laser irradiator to irradiate a laser beam via a laser beam reflector.

Images