KR20050008419A - Apparatus for automatically measuring hall displacement by using contct type displacement sensor - Google Patents

Abstract

PURPOSE: An automatic measurement device is provided to manage a quality of a product by measuring the position of a hole as a specific point. CONSTITUTION: A tool portion(100) contains an upper plate(110), a center plate(120), a lower plate(130) and a conical hall displacement measurement jig(140). The upper plate has many robot joint plates(112,114) to combine a robot with the tool portion. The center plate is movable toward an x-axis direction of the upper plate. The center plate has many displacement sensors. The lower plate contains many displacement sensors. The lower plate is movable toward a y-axis direction of the upper plate. The conical hall displacement measurement jig is installed in the lower part of the lower plate.

Description

Automatic measuring device for measuring hole displacement using contact displacement sensor {APPARATUS FOR AUTOMATICALLY MEASURING HALL DISPLACEMENT BY USING CONTCT TYPE DISPLACEMENT SENSOR}

The present invention relates to a displacement sensor, and more particularly, contact displacement for grasping the degree of manufacture of a large number of manufactured products manufactured in an industrial field, in order to not only judge the accepted product but also to control and improve the quality of the manufactured product. The present invention relates to an automatic measuring device for measuring hole displacement using a sensor.

In general, the displacement sensor refers to a sensor that can take a distance or position change of an object as an analog value, and can be divided into contact type and non-contact type. The contact type includes an automatic transformer, an electromagnetic induction, a magnetic or an optical scale. The non-contact type is eddy current type, optical type or ultrasonic type.

However, these displacement sensors, for example, have the advantage of short measuring distance in the case of contact type, but has a disadvantage of slow response speed, and in the case of optical type, it has a disadvantage of being affected by color. Have

Therefore, recently, in order to overcome this drawback, magnetic sensors using magnetic principles have been actively studied as elements that convert magnetism into electricity. Such devices include simple search coils. They range from super conducting quantum inteference devices.

Conventional magnetic sensors have a number of advantages such as non-contact detection, high reliability with a long life, energy conservation, unaffected by humidity, and relatively inexpensive. Therefore, magnetic sensors have been put to practical use in such fields as displacement, pressure, liquid level, load, vibration measurement, and the like based on these advantages. Among the magnetic sensors, the displacement measuring sensor using a magnetic element conversion method has a different structure and design method depending on the object to be applied, that is, the shape of the measured object, and the mechanical displacement between the primary coil and the secondary coil Transducers that change the magnetic flux, that is, the mutual inductance, which occur in the system are called LVDT (Linear Variable Differential Transformer).

These LVDTs can be used as transducers with excellent characteristics while being less affected by environmental changes by applying them appropriately to the structural form of electromagnetic shielding and measurement object. These types of transducers are based on displacement measurement. It is widely used and studied in universities, laboratories, and laboratories.

On the other hand, it is necessary not only to judge the acceptance product by grasping the production degree of many products manufactured in the industrial field, but also to measure the quality control and quality improvement of the products. For this measurement, the degree of manufacture of the product is determined using various feature points. If the product has a hole in the product, it is very efficient to determine the location of the hole as the feature point.

As a result, various studies have been actively conducted on hall position measurement through a visual sensor such as a vision to identify the position of the hole as a feature point of the manufactured product.

However, the measurement of the position of the hole by the conventional vision or laser vision fusion sensor, etc. has the advantage of non-contact measurement, while the change of measured values is severe depending on the shading condition, and the presence or absence of the hole is determined according to the color of the object to be measured. This difficult case (see Fig. 8) has a disadvantage such as occurs.

The present invention was created to solve the above problems, and the main purpose of the present invention is to indicate the position of the robot so that the conical part of the mechanism of the hole displacement automatic measuring device attached to the robot can be coincident. Then, when a displacement occurs from the hole center to be measured, the mechanism of the automatic hole displacement measuring device generates a displacement in accordance with the contact force generated between the cone and the hole according to the displacement between the specified position and the hole center. It is to provide an automatic measuring device for measuring displacement using a contact displacement sensor.

1 is a cross-sectional view illustrating an automatic measuring device attached to a robot and measuring hall displacement according to a preferred embodiment of the present invention.

Figure 2 shows a plan view for explaining the coupling state of the lower plate and the intermediate plate shown in Figure 1 according to a preferred embodiment of the present invention.

3 is a plan view for explaining a coupling state of the upper plate and the intermediate plate shown in Figure 1 according to a preferred embodiment of the present invention.

4 is a plan view illustrating the robot bonding plate shown in FIG. 1 having a slide guide hole for preventing impact in accordance with a preferred embodiment of the present invention.

5 is a cross-sectional view for explaining the conical hole displacement measuring jig variously designed in accordance with a preferred embodiment of the present invention.

FIG. 6 is a diagram for schematically explaining an experimental configuration for measuring a hole displacement measured using an automatic measuring device for measuring hall displacement manufactured according to a preferred embodiment of the present invention. .

FIG. 7 shows a flow chart of an experimental method for measuring hole displacement using an automatic measuring device for measuring hall displacement manufactured according to a preferred embodiment of the present invention.

FIG. 8 illustrates a photograph for describing a vision image of a hole formed in an object for measuring in FIG. 7.

9 is a graph showing an experimental result of repeatedly measuring the center position of a hole using an automatic measuring device for measuring hole displacement manufactured according to a preferred embodiment of the present invention.

-Explanation of symbols for the main parts of the drawings-

100: hole displacement automatic measuring device 110: upper plate

111-114: robot junction plate 120: center plate

130: lower plate 140: conical hole displacement measuring jig

The present invention for realizing the above object includes a robot and a mechanism portion, the mechanism portion having a plurality of robot bonding plate for coupling the mechanism portion to the robot, and a plurality of displacement sensors and x on the upper plate A central plate capable of moving in the axial direction, a lower plate having a plurality of displacement sensors and capable of moving in the y-axis direction with respect to the central plate, and a conical hole displacement measuring jig installed under the lower plate. An automatic measuring device for measuring hole displacement using a contact displacement sensor is provided.

Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings. In addition, this embodiment is not intended to limit the scope of the present invention, but is presented by way of example only.

1 to 9 show various views for explaining an automatic measuring device for measuring hall displacement attached to a robot in accordance with a preferred embodiment of the present invention.

1 is a cross-sectional view illustrating an automatic measuring device attached to a robot and measuring hall displacement according to a preferred embodiment of the present invention.

First, according to a preferred embodiment of the present invention, the automatic hole displacement measuring device constitutes a sliding joint of the LM guide type, the center plate 120 can move along the x-axis by the upper plate 110, The lower plate 130 is designed to allow movement along the y-axis with respect to the center plate 120.

In addition, a conical hole displacement measuring jig 140 is installed on the lower plate 130, and a linear variable differential transformer (LDVT) sensor is coupled to the center plate 120 in the case of the x-axis, and the lower plate in the case of the y-axis. It is coupled to the 130 to configure the mechanism portion 100 of the automatic hole displacement measuring device.

Thus, by mounting the mechanical part 100 of the automatic hole displacement measuring apparatus according to the preferred embodiment of the present invention mounted on an industrial robot to enter the designated hole center point, the hole and the conical hole displacement measuring jig 140 to be measured The contact force generated between the cones causes the mechanism 100 of the hole displacement automatic measuring device to cause displacement in the x-axis and y-axis directions, thereby measuring the displacement from the center of the test hole.

Figure 1 shows the overall view of the mechanism 100 of the automatic hole displacement measuring apparatus mounted on the robot according to a preferred embodiment of the present invention, it can be understood as described above, the hole generated between the robot and the measurement target The error perpendicular to the plane (error between the robot teaching point and the hole of the object to be measured) was solved by attaching a sliding guide to the robot attachment part and using gravity and the repulsive force of the spring 116.

Figure 2 shows a plan view for explaining the coupling state of the lower plate and the intermediate plate shown in Figure 1 according to a preferred embodiment of the present invention.

As shown in FIG. 2, the coupling between the lower plate 130 and the central plate 120 and the installation portion of the LVDT sensor probe can be understood, and the coupling between the lower plate 130 and the central plate 120 may provide a roller joint. Is made through and constitutes a sliding joint 150 in the vertical direction of FIG. Therefore, the LVDT sensor probe attached to the lower plate 130 may be installed in the vertical direction and measure the displacement of the lower plate 130 with respect to the center plate 120.

3 is a plan view for explaining a coupling state of the upper plate and the intermediate plate shown in Figure 1 according to a preferred embodiment of the present invention. Reference numerals 116a, 116b, 116c and 116d denote four springs installed for proper cushioning effect.

As shown in FIG. 3, the coupling of the upper plate 110, the center plate 120, and the lower plate 130 and the installation of the LVDT sensor probes can be seen. As described above, the upper plate 110 and the center plate 120 is made through the roller joint, the sliding joint 150 is configured in the horizontal direction of Figure 2, the LVDT sensor probe attached to the center plate 120 Is installed in the horizontal direction and can measure the displacement of the center plate 120 with respect to the upper plate (110). In addition, according to a preferred embodiment of the present invention, the combination of the upper plate 110, the center plate 120 and the lower plate 130 through the roller joint used an eccentric nut to make the assembly tolerance.

4 is a plan view illustrating the robot bonding plate shown in FIG. 1 having a slide guide hole for preventing impact in accordance with a preferred embodiment of the present invention.

As shown in FIG. 4, a plurality of robot bonding plates 111-114 for coupling the robot part 100 with the mechanism 100 of the hole displacement automatic measuring device and a sliding guide to compensate for the impact and the vertical error of the robot (a kind of Prismatic joints). In addition, four springs are installed between the upper plate 110 and the plurality of robot bonding plates 111-114 for proper buffering effect.

5 is a cross-sectional view for explaining the conical hole displacement measuring jig variously designed in accordance with a preferred embodiment of the present invention. In general, the larger the display angles θ1, θ2, and θ3, the greater the contact force, but according to a preferred embodiment of the present invention, considering the depths of the holes d1, d2, d3 and the widths w1, w2, w3, The display angle was adjusted.

FIG. 6 is a diagram for schematically explaining an experimental configuration for measuring a hole displacement measured using an automatic measuring device for measuring hall displacement manufactured according to a preferred embodiment of the present invention. .

The automatic measurement system for measuring the hole displacement using the contact displacement sensor according to the preferred embodiment of the present invention controls the robot 200 equipped with the contact displacement sensor and the robot 200 equipped with the contact displacement sensor. The robot includes a general-purpose controller 210, an object to be measured 240, an LVDT indicator 220 for displaying an LVDT value measured by a contact displacement sensor, and a personal computer 230 for data acquisition.

FIG. 7 shows a flow chart of an experimental method for measuring hole displacement using an automatic measuring device for measuring hall displacement manufactured according to a preferred embodiment of the present invention.

First, the robot is taught to coincide with the conical portion of the conical hole displacement measuring jig 140 of the mechanism 100 of the hole displacement automatic measuring device attached to the robot (S100). Then, measurement starts (S110). The robot moves as taught (S120).

In the next step, it is determined whether the robot has reached the position of the object (S130). If it has not reached the position of the object, the process returns to step S120 again to move the robot. On the other hand, if the robot reaches the position of the object outputs a signal from the robot controller (now MMC controller) (S150).

Then, the LVDT indicator 220 is operated (S150), and it is determined whether all data have been received (S160). If all data S160 has not been received, the process returns to step S150 again. However, if all data has been received, the correct data is selected (S170).

Subsequently, by determining the hole position (S180), the method for automatically measuring the hole displacement using the contact displacement sensor according to the preferred embodiment of the present invention is completed.

According to a preferred embodiment of the present invention, after teaching the robot so that the conical portion of the conical hole displacement measuring jig 140 of the mechanism part 100 of the hole displacement automatic measuring device attached to the robot 200 coincides with, When the displacement of the hole center to be measured occurs, the mechanism 100 of the hole displacement automatic measuring device generates a displacement according to the contact force generated between the cone and the hull according to the displacement between the teaching point and the hole center, and the generated displacement And a hole contact measuring mechanism unit for measuring the temperature using an LVDT sensor, and an automatic hole position measuring system for storing and managing the measured information in the personal computer 230 for data acquisition through RS232 serial communication.

FIG. 8 illustrates a photograph for describing a vision image of a hole formed in an object for measuring in FIG. 7. The hole center recognition of such an image is too large compared to the present invention, the error of the center value according to the illumination state obtained an experimental result that can not be compared.

9 is a graph showing an experimental result of repeatedly measuring the center position of a hole using an automatic measuring device for measuring hole displacement manufactured according to a preferred embodiment of the present invention. By using an automatic measuring device using a contact displacement sensor according to a preferred embodiment of the present invention shows the measurement results when the hole displacement of the hole shown in Figure 8 is measured 100 times. According to the measurement results, it can be seen that the present invention guarantees a precision of about 0.01 mm.

Although the repeatability of the robot is guaranteed to be about 0.05mm in the entire operating area, the repeating test result of the present invention guarantees the measurement accuracy to 0.01mm at the robot measurement position specified in the present experiment, and does not attach the measuring mechanism to the robot. After fixing, it can be seen that up to 0.002mm is guaranteed if the object is approached.

While the invention has been described in accordance with some preferred embodiments herein, those skilled in the art will recognize that many modifications and improvements can be made without departing from the true scope and spirit of the invention as set forth in the appended claims.

As described above, if the present invention has a hole in the interior of the product, by measuring the position of the hole as a feature point, not only the presence or absence of product defects can be determined, but also the degree of product of the entire product can be determined. It is very useful for management.

In addition, the present invention has the effect of ensuring the measurement accuracy up to 0.01 mm, especially for the object difficult to measure with a visual sensor such as vision.

Claims (3)

Including robots and mechanisms, The mechanism part An upper plate having a plurality of robot bonding plates for coupling the mechanism to the robot; A central plate having a plurality of displacement sensors and capable of moving in the x-axis direction on the upper plate; A lower plate having a plurality of displacement sensors and movable in a y-axis direction with respect to the central plate; Automatic measuring device for measuring the hole displacement using a contact displacement sensor, characterized in that it comprises a conical hole displacement measuring jig installed in the lower portion of the lower plate. The contact type of claim 1, wherein the upper plate, the center plate, and the lower plate have an xy sliding joint configuration through engagement with a roller and use an eccentric nut for making a coupling tolerance through the roller. Automatic measuring device for measuring hole displacement using displacement sensor. The apparatus of claim 1, wherein the plurality of displacement sensors provided in the center plate and the lower plate are linear variable differential transformer (LVDT) sensors. .