KR101673978B1

KR101673978B1 - Robotic Arm System and Method for calibrating Parallelism of the Same

Info

Publication number: KR101673978B1
Application number: KR1020140096431A
Authority: KR
Inventors: 우-텡 흐시에; 헌-슝 전; 장-신 쿼; 야오-쩐 장
Original assignee: 하이윈 테크놀로지스 코포레이션
Priority date: 2014-06-26
Filing date: 2014-07-29
Publication date: 2016-11-08
Also published as: JP5943970B2; CN105215990B; JP2016007696A; DE102014110548A1; KR20160001558A; TW201600275A; CN105215990A; TWI561354B

Abstract

The present invention relates to a robot arm system comprising a robot arm, a controller and a parallelism correcting device, wherein the robot arm has an end short axis and the end short axis has an end face, the parallelism correcting device is provided at the end face, It has one distance meter. The parallelism correction method of the robot arm system first moves the end short axis to a calibration position adjacent to the reference plane and then causes the parallelism correction device to measure the difference in distance between at least three measured points on the reference plane and the end, Signal to the controller, and the controller again adjusts the posture of the robot arm according to the measurement signal so that the distances between the measured points and the end surface are all equal to each other. The present invention thus enables the robotic arm to quickly achieve accurate parallelism with the working plane in various working situations.

Description

Technical Field [0001] The present invention relates to a robot arm system and a method for correcting the parallelism,

The present invention relates to a robot arm, and more particularly, to a robot arm system having a parallelism correcting function and a parallelism correction method thereof.

When the robot arm performs a specific operation, the end surface of the robot arm is generally parallel to the work plane so that an effector installed on the end surface can smoothly work. For example, the end effector may be a clamping jaw for clamping the shaft lever and inserting the shaft lever into an insertion hole on a working plane of a hole plate, and the robot arm is configured to insert the shaft lever into the insertion hole , The end face must be parallel to the working plane.

With reference to U.S. Pat. No. 5,218,550, the patent provides a support surface to the machine station and secures the base of the robot arm to the support surface such that a specific portion of the robot arm is parallel to a specific axial direction of the machine station. However, according to the method described above, the angle of the robot arm can not be arbitrarily changed according to different demands of the work, and if the machining accuracy of the support surface is poor, the parallelism between the robot arm and the machine station can be secured none.

In fact, robotic arms are typically used for a variety of tasks and their coordinate system is difficult to match the coordinate system of the corresponding working device (eg pick & place platform, hole plate, etc.) There is considerable difficulty in correcting the parallelism of the working plane of the corresponding working apparatus. In particular, robot arm may need to cope with a relatively complicated tilting working plane, and parallelism correction becomes more difficult in this situation.

SUMMARY OF THE INVENTION In view of the above problems, it is a primary object of the present invention to provide a robot arm system and its parallelism correction method which can quickly achieve a working plane and precise parallelism even in various operations.

In order to achieve the above object, the present invention provides a robot arm system, wherein the robot arm system includes a robot arm, a controller for controlling the operation of the robot arm, and a parallelism correcting device. The robot arm has a terminal short axis and the terminal short axis has a terminal cross-section. The parallelism correcting apparatus is provided at the end short axis and has at least one distance measuring instrument. The distance measuring instrument measures a distance difference between at least three measured points on the one reference surface and the end surface, and transmits a measurement signal to the controller .

The present invention further provides a method for correcting parallelism of a robot arm system as described above, comprising the following steps.

a. Moving the short axis to a calibration position adjacent the reference plane;

b. Measuring the distance difference between the measurement point on the reference surface and the end surface and transmitting a measurement signal to the controller; And

c. Wherein the controller adjusts the posture of the robot arm according to a measurement signal transmitted by the parallelism correcting device so that the distance between the measured point and the end surface is the same.

Whereby when the distances between the at least three measured points on the reference surface and the end surface are all the same, the end surface is parallel to the reference surface. The reference surface may be the surface of the calibration plate and the surface is parallel to the working plane when the robotic arm proceeds after the step c. In this case, since the end surface is parallel to the reference surface after step c, it is also parallel to the working plane. Alternatively, the reference surface may be a working plane at which the robot arm proceeds after the step c, so that the end plane is parallel to the working plane after the step c.

In other words, the present invention can directly correct the parallelism between the end surface of the robot arm and the working plane, or indirectly correct the parallelism between the end surface of the robot arm and the working plane by using the calibration plate. Even if the work plane is arbitrarily changed and the coordinate system is applied to a relatively complicated inclined working plane, the present invention can quickly bring the end surface of the robot arm to the working plane and the accurate parallelism.

The details of the structure, feature, assembly or use of the robot arm system and its parallelism correction method according to the present invention will be described in the detailed description of the embodiments to be described later. It will be understood by those skilled in the art that these detailed description and the specific examples listed for carrying out the invention are merely illustrative of the invention and are not intended to limit the scope of the claims of the invention It will be possible.

According to the present invention, the robot arm can quickly achieve accurate parallelism with the working plane in various working situations.

1 is a schematic perspective view of a robot arm system according to a first preferred embodiment of the present invention;
FIG. 2 is a perspective exploded view of a robot arm and a parallelism correcting apparatus of a robot arm system according to the first preferred embodiment of the present invention; FIG.
FIGS. 3 and 4 are a plan perspective view and a schematic perspective view of the use of a robot arm system according to the first preferred embodiment of the present invention;
5 is a plan perspective view of another embodiment of the robot arm system according to the first preferred embodiment of the present invention;
6 is a schematic perspective view of a robot arm and a parallelism correcting apparatus of a robot arm system according to a second preferred embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Before describing the present invention, the applicants intend to explain that the same reference numerals designate the same or similar components or their constituent features in the following embodiments and drawings. When a part is said to be installed on another part, the above-mentioned part is directly installed on the other part, or the above-mentioned part is indirectly installed on the other part, that is, one or a plurality of other parts Indicating that there is more installed.

1 and 2, a robot arm system 10 according to a first preferred embodiment of the present invention includes a robot arm 20, a controller 30, and a parallelism correcting apparatus 40. [

The robot arm 20 is the same as the conventional robot arm, and can be changed to various postures under the control of the controller 30. [ The robot arm 20 has an end short axis 22 for mounting an end runner (not shown), and controls the operation of the robot arm 20 by the controller 30. The end shafts 22 can move to different positions and can achieve different work demands by implementing different angles. In this embodiment, the end short axis 22 has an end face 222 and the end short axis 22 can rotate about a virtual axis L perpendicular to the end face 222.

The parallelism correcting apparatus 40 includes a base 41 and a distance measuring instrument 42 fixed to the base 41. The base 41 is connected to the end 41 of the end short axis 22 of the robot arm 20, And is fixed to the end surface 222. That is, since the parallelism correcting device 40 is installed on the end short axis 22, it can rotate together with the end short axis 22. In this embodiment, the distance measuring instrument 42 is provided with a telescoping measuring instrument (for example, a dial gauge having a precision of 0.01 mm or a dial gauge having a precision of 0.001 mm) and a retractable measuring lever 422. The measurement lever 422 is parallel to the imaginary axis L, that is, perpendicular to the end surface 222. However, the distance measuring instrument 42 may be a non-contact measuring instrument (for example, a laser distance measuring instrument, an infrared distance measuring instrument, etc.) Parallel.

Hereinafter, a method for correcting the parallelism of the robot arm system 10 will be described taking the use of the robot as an example of the use shown in Figs. 3 and 4 show a work table 51 and a work device 52 (for example, a pick and place platform, a hole plate, etc.) mounted on the mounting surface 512 of the work table 51 , The working device (52) has a working plane (53). The parallelism correction method is for paralleling the end surface 222 to the working plane 53 when the robot arm 20 is working on the working plane 53, and includes the following steps.

a. The end shank 22 is moved to a calibration position P adjacent to the reference surface 54.

The mounting surface 512 of the work table 51 is further provided with a calibration plate 55. The reference surface 54 is one surface of the calibration plate 55, And is parallel to the working plane 53. The measuring lever 422 of the distance measuring device 42 is positioned at the reference surface 54 when the end measuring shaft 22 is positioned at the calibration position P . However, when the non-contact distance measuring instrument 42 is used, the distance measuring instrument 42 need not contact the reference plane 54, but only the reference plane 54 can be measured.

b. The parallelism correction apparatus 40 measures a distance difference between at least three measured points on the reference plane 54 and the end plane 222 and transmits a measurement signal to the controller 30. [

The measuring lever 422 of the distance measuring device 42 is continuously brought into contact with the reference surface 54 while rotating the end shaft 22 one rotation (may rotate only at a predetermined angle) And the measurement lever 422 is rotated along the end short axis 22 to slide along the circular (or arcuate) imaginary locus 56 on the reference plane 54, Measure the measuring point. If the end surface 222 is not parallel to the reference surface 54, there is a difference in distance between the measured points and the end surface 222, and the controller 30 causes the reference surface 54 The angle of inclination of the end surface 222 can be estimated.

c. The controller 30 adjusts the posture of the robot arm 20 according to the measurement signal transmitted by the parallelism correcting device 40 so that the distance between the measured point and the end surface 222 is the same.

If the distance between the measurement point on the reference surface 54 and the end surface 222 is the same, the end surface 222 is parallel to the reference surface 54. After the step c, the end surface 222 is parallel to the reference plane 54 and thus parallel to the working plane 53 when the robot arm 20 is working on the working plane 53.

However, the method of correcting the parallelism of the robot arm device described above may not necessarily use the calibration plate 55. The mounting surface 512 of the work table 51 may be the reference surface 54, The working plane 53 may be used as the reference plane 54. This calibration method is more direct and accurate. 5, when the working plane 53 is tilted with respect to the mounting surface 512 and furthermore a more complicated coordinate system exists, the working plane 53 is directly aligned with the reference plane 54 So that the parallelism of the end surface 222 and the working plane 53 can be corrected quickly and accurately.

Referring to FIG. 6, the robot arm system according to the second preferred embodiment of the present invention uses a parallelism correcting apparatus 60 different from the first preferred embodiment. The parallelism correcting apparatus 60 includes a base 61 and two fixed distance measuring devices 64 and a fixed length reference rod 62 fixed to the base 61. Each of the distance measuring devices 64, Contact measuring device such as the distance measuring device 42 according to the first preferred embodiment. The reference rod 62 and the measurement lever 642 (or the measurement light beam) of the two distance measuring devices 64 are all perpendicular to the end surface 222 of the robot arm 20 (as shown in FIG. 2 equivalence).

The parallelism correction method of the robot arm system according to the present embodiment includes steps a, b, c similar to the first preferred embodiment. Referring to FIGS. 3 and 6, in step a of the present embodiment, the reference bar 62 is brought into contact with the reference surface 54. That is, when the end short axis 22 is located at the calibration position P, the reference rod 62 contacts the reference surface 54, and the contact point thereof becomes the measured point. The distance between the measured point and the reference surface 54 is a known fixed value (i.e., the sum of the length of the reference rod 62 and the thickness of the base 61). In the step b of the present embodiment, the reference rod 62 still contacts the measured point, the two distance measurers 64 contact the reference plane 54, and the contact point is the other two measured points. In this way, the parallelism correcting apparatus 60 measures the distance difference between the three measured points and the end surface 222 without rotating the controller 30 so that the controller 30 can measure the distance between the end The inclination of the end surface 222 can be estimated and the end surface 222 of the robot arm 20 is parallel to the reference surface 54 by adjusting the posture of the robot arm 20.

In summary, the present invention can directly correct the parallelism between the end surface 222 of the robot arm 20 and the working plane 53, or can directly correct the parallelism between the end surface 222 of the robot arm 20 and the end surface 222 of the robot arm 20, It is possible to indirectly calibrate the parallelism of the work plane 222 and the working plane 53. [ This method is quite fast and accurate and even if the working plane 53 is arbitrarily changed or even applied to a relatively complex tilting working plane 53, the present invention still allows the end surface 222 of the robot arm 20 It is possible to quickly make an accurate parallelism with the working plane 53.

Finally, the components disclosed in the above-described embodiments of the present invention are described by way of example and are not intended to limit the scope of the present invention. Alternatives or variations of other equivalent elements should also be included in the claims of the present invention.

10: Robot arm system
20: Robot arm
22: End shortening
222: end face
30: Controller
40: parallelism correction device
41: Base
42: Distance measuring instrument
422: Measuring lever
51: work table
512: Mounting surface
52: working device
53: Working plane
54: Reference plane
55: Calibration plate
56: Virtual trajectory (measured point)
60: parallelism correction device
61: Base
62: Reference bar
64: Distance meter
642: Measuring lever
L: virtual axis
P: Calibration position

Claims

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A robot arm having an end short axis, the end short axis having an end section; A controller for controlling the operation of the robot arm; And a distance measuring device provided at an end surface of the end shaft to measure a distance between at least three measured points on the reference surface and the end surface to transmit a measurement signal to the controller, Wherein the end shaft of the robot arm is rotatable about a virtual axis perpendicular to the end surface, the distance measuring device of the parallelism correcting device is detached from the virtual axis and installed at the end short axis, In the parallelism correction method of the robot arm system,
The calibration method includes:
a. Moving the short axis to a calibration position adjacent the reference plane;
b. Measuring a difference in distance between a measured point on the reference surface and the end surface and transmitting a measurement signal to the controller after the end short axis is rotated; And
c. Adjusting the posture of the robot arm according to a measurement signal transmitted by the parallelism correcting apparatus so that the distance between the measured point and the end surface is the same;
Lt; / RTI >
Wherein the end short axis of the robot arm is rotatable around a virtual axis perpendicular to the end surface and the parallelism correcting device includes one distance measurer separated from the virtual axis and provided on the end short axis, Wherein the distance measuring device measures the plurality of measured points according to the rotation of the end short axis,
A method for correcting parallelism of a robot arm system.

The method of claim 3,
Wherein said distance measuring instrument is in contact with said reference surface when said end short axis is located at said calibration position and in said step b.

The method of claim 3,
Wherein the reference surface is a surface of a calibration plate and the surface is parallel to a working plane when the robot arm proceeds to work after step c.

The method of claim 3,
Wherein the reference plane is a working plane when the robot arm proceeds to work after step c.

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