JP2000210889A - Industrial robot - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily determine the position and attitude of a tool mounting part without executing the special operation by providing an attitude holding mechanism for constantly maintaining the attitude of the tool mounting part in relation to a base regardless of the attitude of a link. SOLUTION: An attitude maintaining mechanism for constantly maintaining the attitude of a tool mounting part 13 in relation to a base 3 regardless of the attitude of a link 2, comprises the pulleys 7, 8 having the same diameter and relatively rotatably supported in relation to the link 2, a pulley 9 stational at all times and the belts 11, 12. Thereby, the attitude of the tool mounting part 13 can constantly be maintained in relation to the base 3 at all times even through the attitude of the tool mounting part 6 is changed. Accordingly, the coordinates of the tool mounting part 13 can be determined only by adding a constant coordinate value to a coordinate value on a horizontal plane of the tool mounting part 6, and the position and attitude of the tool mounting part 13 can be determined without executing a special operation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an industrial robot for performing operations such as processing, transporting, assembling and inspecting articles.

[0002]

2. Description of the Related Art FIG. 6 is a side view showing a conventional industrial robot disclosed in, for example, JP-A-6-55485. In the figure, reference numeral 31 denotes one end connected to a base 33 via a rotary joint 34. Link 32, one end is a rotary joint 3
5, a link 33 connected to the other end of the link 31 via
Is a base of an industrial robot, 34 is a rotating joint driven by a driving means such as a motor, 35 is a rotating joint driven by a driving means such as a motor, 36 is provided at the other end of the link 32, and a tool 37 is mounted. Reference numeral 37 denotes a tool for assembling an article, for example, and reference numeral 38 denotes an image pickup means provided at the distal end of the link 32 for picking up an image of a work object below.

Next, the operation will be described. Revolute joint 34
And the rotating joint 35 are independently driven by a driving means (not shown) such as a motor. When the rotating joint 34 and the rotating joint 35 are driven by the driving means, the link 31 and the link 31 The angle of the link 32 is determined, and as a result, the position of the tool mounting part 36 in the horizontal direction (perpendicular to the paper surface) is determined.

Further, the tool mounting portion 36 is driven by another driving means (not shown), and the position of the tool mounting portion 36 in the vertical direction or the position around the central axis of the tool mounting portion 36 (the position in the text means an angle in a horizontal plane). Meaning). Then, the image capturing means 38 captures an image of the lower work object while maintaining a relative positional relationship with respect to the link 32, and the captured image information is used for position confirmation and position correction.

[0005]

Since the conventional industrial robot is constructed as described above, it is stationary because the horizontal position of the image pickup means 38 depends on the position of the link 32. When imaging the work target, link 3
When the posture of the image pickup device 2 changes, there is a problem that it is necessary to correct the reference in the rotation direction of the image captured by the image capturing means 38. When the position of the work object changes, the position of the imaging means 38, that is, the position of the link 32, needs to be changed in accordance with the position of the work object. A special calculation for adjusting the position of the imaging means 38 to the position of the work target is required, and there has been a problem that the control becomes complicated.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and does not require any special calculation.
An object of the present invention is to provide an industrial robot that can easily determine the position and orientation of a tool mounting unit. Another object of the present invention is to provide an industrial robot that can save the trouble of correcting the angle reference of an image even when an imaging unit is mounted on a tool mounting unit.

[0007]

An industrial robot according to the present invention is provided with a posture holding mechanism for keeping a posture of a second tool mounting portion with respect to a base constant irrespective of a posture of a second link. It is.

[0008] An industrial robot according to the present invention comprises a first pulley fixed to a stationary shaft coaxial with a first rotary joint;
A second pulley rotatably mounted on a rotary shaft coaxial with the second rotary joint; and a second pulley rotatably mounted on a rotary shaft coaxial with the rotary shaft of the first tool mounting portion. Using a third pulley that supports the tool mounting portion, a first belt that connects the first pulley and the second pulley, and a second belt that connects the second pulley and the third pulley. And constitute a posture holding mechanism.

In the industrial robot according to the present invention, four vertices are rotatably connected, and a first parallelogram link having a first link on one side and four vertices are rotatably connected. , And a second parallelogram link having a second link on one side to constitute a posture holding mechanism.

[0010] An industrial robot according to the present invention mounts an image pickup means for picking up an image of a work space or a first tool mounting portion on a second tool mounting portion.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below. Embodiment 1 FIG. FIG. 1 is a plan view showing an industrial robot according to Embodiment 1 of the present invention. FIG. 2 is a side sectional view showing an industrial robot according to Embodiment 1 of the present invention. 4 is a link (first link) connected to the base 3 via 4, 2 is a link (second link) connected at one end to the other end of the link 1 via the rotary joint 5, 3 is an industrial robot , 4 is a rotary joint (first rotary joint) driven by drive means such as a motor, 5 is a rotary joint (second rotary joint) driven by drive means such as a motor, and 6 is the link 2 A tool mounting portion (first tool mounting portion) that is provided at the other end and moves vertically or rotationally with respect to the link 2.

Reference numeral 7 denotes a pulley (first pulley) fixed to a stationary shaft coaxial with the rotary joint 4, and reference numeral 8 denotes a pulley (second pulley) rotatably mounted on a rotary shaft coaxial with the rotary joint 5. ) And 9 are rotatably mounted on a rotation axis coaxial with the rotation axis of the tool mounting unit 6, and a pulley (third pulley) supporting the tool mounting unit 13 is fixed to the base 3 by the pulley 10. A connecting portion, 11 is a belt (first belt) connecting the pulley 7 and the pulley 8, 12 is a belt (second belt) connecting the pulley 8 and the pulley 9, and 13 is rotatably supported by the pulley 9. The tool mounting unit (second tool mounting unit) 14 is an imaging unit such as a camera that is mounted by the tool mounting unit 13 and captures an image of the work space or the tool mounting unit 6. The pulleys 7, 8, 9 and the belts 11, 12
Constitute a posture holding mechanism.

Next, the operation will be described. The rotating joints 4 and 5 are independently driven by driving means (not shown) such as a motor. When the rotating joints 4 and 5 are driven by the driving means, the link 1 connected to each joint is driven. The angle of the link 2 is determined, and as a result, the position of the tool mounting portion 6 in the horizontal direction (vertical direction of the paper surface in FIG. 2) is determined. Further, the tool mounting section 6 is provided with another driving means (not shown).
And a posture around the center axis of the tool mounting portion 6 (the posture in the text means an angle in a horizontal plane).

The pulleys 7, 8 which are rotatably supported relative to the link 2 and have the same diameter, and the pulley 9 which is always stationary (the diameter of the pulley 9 is equal to the diameter of the pulleys 7, 8) ) And belts 11 and 12, link 2
Irrespective of the posture of the tool, the tool mounting portion 13 with respect to the base 3
Thus, even if the posture of the tool mounting unit 6 changes, the posture of the tool mounting unit 13 is always kept constant with respect to the base 3 even if the posture of the tool mounting unit 6 changes.

Thus, a constant coordinate value is always added to the coordinate value of the tool mounting section 6 in the horizontal plane.
Since the coordinates of the tool mounting section 13 can be obtained, the position and orientation of the tool mounting section 13, that is, the position and attitude of the imaging unit 14 can be obtained without performing any special calculation.

Embodiment 2 FIG. 3 is a side sectional view showing an industrial robot according to Embodiment 2 of the present invention. In the figure, the same reference numerals as those in FIG. 2 denote the same or corresponding parts, and a description thereof will be omitted. 15 is a sub-link fixed to link 1 (not shown), and 16 is a sub-link fixed to link 2 (not shown).

Next, the operation will be described. In the structure having the structure shown in FIG. 3, the connecting portion 10 is fixed to the base 3 (not shown), the sub-link 15 is connected to the link 1 (not shown), and the sub-link 16 is connected to the link 2 (not shown). , The attitude of the tool mounting portion 13 is always kept constant with respect to the base 3 irrespective of the attitude of the link 2 as in the first embodiment. In the second embodiment, the pulley 9 has a penetrating portion centered on the central axis, and has a structure that can be attached to and detached from the horizontal joint type robot.

Embodiment 3 FIG. 4 is a plan view showing an industrial robot according to Embodiment 3 of the present invention. In the figure, the same reference numerals as those in FIG. 1 denote the same or corresponding parts, and a description thereof will be omitted. Reference numeral 17 denotes a link having one end connected to the other end of the link 2 via a rotary joint (not shown); 18 denotes one end connected to the other end of the link 17 via a rotary joint 19;
The other end is a link rotatably connected to the base 3 via the rotary joint 20, and 19 and 20 are rotary joints.

Next, the operation will be described. The rotating joint 4 and the rotating joint 20 are independently driven by driving means (not shown) such as a motor. When the rotating joints 4 and 20 are driven by the driving means, the link 1 connected to each joint is driven.
And the angle of the link 18 is determined. On the other hand, since the rotating joints 5 to 19 have no active driving means, when the angles of the links 1 and 18 are determined, the links 2 and 17
Is also determined.

As a result, the horizontal position of the tool mounting section 6 is determined. Further, the tool mounting unit 6 is driven by another driving means (not shown), and the vertical position or the attitude of the tool mounting unit 6 around the central axis is determined. Note that the posture of the tool mounting unit 6 is always held constant with respect to the base 3 by the same posture holding mechanism as in the first embodiment.

Embodiment 4 FIG. FIG. 5 is a plan view showing an industrial robot according to Embodiment 4 of the present invention. In the figure, the same reference numerals as those in FIG. 1 denote the same or corresponding parts, and a description thereof will be omitted. 21 is an auxiliary link parallel to link 1,
Reference numeral 22 denotes an auxiliary link parallel to the link 2, and reference numeral 23 denotes an auxiliary link parallel to the connecting portion 10 fixed to the base 3 and having a rotation center axis coaxial with the rotating joint 5. The link 1, the connecting portion 10, the auxiliary link 21, and the auxiliary link 23 constitute a first parallelogram link in which adjacent portions (vertexes) are rotatably connected to each other.
The auxiliary link 22 and the tool mounting portion 13 constitute a second parallelogram link in which adjacent portions (vertexes) are rotatably connected to each other.

Next, the operation will be described. The operation for determining the position of the tool mounting unit 6 is the same as that in the first embodiment, and thus the description is omitted. Since the tool mounting portion 13 is connected to the base 3 via the first parallelogram link and the second parallelogram link, the stationary side (the base side of the first parallelogram link) , The posture is kept constant with respect to the base 3.

[0023]

As described above, according to the present invention, the second
Irrespective of the attitude of the link, the attitude of the second tool mounting portion with respect to the base is configured to be provided with an attitude holding mechanism, so that no special calculation is performed.
There is an effect that the position and orientation of the tool mounting portion can be easily obtained.

According to the present invention, the first pulley fixed to the stationary shaft coaxial with the first rotary joint and the second pulley rotatably mounted on the rotary shaft coaxial with the second rotary joint. And a third pulley rotatably mounted on a rotation axis coaxial with the rotation axis of the first tool mounting portion and supporting the second tool mounting portion; a first pulley and a second pulley; Since the posture holding mechanism is configured by using the first belt connecting the pulleys and the second belt connecting the second pulley and the third pulley, the posture holding mechanism is configured by simple members. There is an effect that can be.

According to the present invention, the four vertices are rotatably connected, the first parallelogram link having the first link on one side and the four vertices are rotatably connected, and the second
And the second parallelogram link having one side on one side constitutes the posture holding mechanism, so that there is an effect that the posture holding mechanism can be constituted by simple members.

According to the present invention, since the image pickup means for picking up an image of the work space or the first tool mounting portion is configured to be mounted on the second tool mounting portion, even if the image pickup means is mounted on the tool mounting portion. This has the effect of eliminating the need to correct the image angle reference.

[Brief description of the drawings]

FIG. 1 is a plan view showing an industrial robot according to Embodiment 1 of the present invention.

FIG. 2 is a side sectional view showing the industrial robot according to Embodiment 1 of the present invention.

FIG. 3 is a side sectional view showing an industrial robot according to Embodiment 2 of the present invention.

FIG. 4 is a plan view showing an industrial robot according to Embodiment 3 of the present invention.

FIG. 5 is a plan view showing an industrial robot according to Embodiment 4 of the present invention.

FIG. 6 is a side view showing a conventional industrial robot.

[Explanation of symbols]

1 link (first link), 2 link (second link), 3 base, 4 revolute joint (first revolute joint), 5
Revolving joint (second revolving joint), 6 tool mounting part (first tool mounting part), 7 pulley (first pulley), 8
Pulley (second pulley), 9 pulley (third pulley), 11 belts (first belt), 12 belts (second belt), 13 tool mounting section (second tool mounting section), 14 imaging means.

Claims (4)

[Claims] 1. A first link having one end connected to a base via a first rotary joint, and a second link having one end connected to the other end of the first link via a second rotary joint. A first tool mounting portion mounted on the other end of the second link, and a second tool rotatably mounted on a rotation axis coaxial with a rotation axis of the first tool mounting portion. An industrial robot comprising: a tool mounting part according to (1), and a posture holding mechanism for maintaining a constant posture of the second tool mounting part with respect to the base regardless of a posture of the second link. A first pulley fixed to a stationary shaft coaxial with the first rotary joint; a second pulley rotatably mounted on a rotary shaft coaxial with the second rotary joint; A third pulley, which is rotatably mounted on a rotation axis coaxial with the rotation axis of the first tool mounting portion and supports the second tool mounting portion, connects the first pulley and the second pulley. 2. The industrial robot according to claim 1, wherein a posture maintaining mechanism is configured by using a first belt that performs the operation and a second belt that connects the second pulley and the third pulley. 3. The method according to claim 1, wherein the four vertices are rotatably connected to each other.
A first parallelogram link having one link on one side;
Vertices are rotatably connected to each other to form a posture holding mechanism using a second parallelogram link having a second link on one side, and a first side of the first parallelogram link on the base side in the first parallelogram link. The side is a stationary side fixed on the base, the second side opposite to the stationary side constitutes a first side of the second parallelogram link, and a vertex of the second parallelogram link is One position is coaxial with the rotation axis of the first tool mounting portion, and the second tool mounting portion is fixed to a second side opposite to the first side of the second parallelogram link. The industrial robot according to claim 1, wherein: 4. The apparatus according to claim 1, wherein an image pickup means for picking up an image of the work space or the first tool mounting portion is mounted on the second tool mounting portion. Industrial robot.