JPS6052278A - Industrial robot - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention supports a control axis X that supports another control axis that can be positioned in the same direction as the control axis, or a plurality of other control axes that can be positioned at least in a plane including the X-axis direction. The present invention also relates to an industrial robot having position control means for these control axes.

The above-mentioned robot is, for example, disclosed in Japanese Patent Application Laid-Open No. 58-8157.
No. 1, etc. are publicly known.

By the way, when controlling the position of the controlled object in the X direction of such a robot to a different position, since the entire weight of the structure supported by the controlled object is a dog, an inertial force acts, and the previously taught X axis Difficult to stop in position. Alternatively, in the case of a type in which the mitoswitches are lined up in the X direction and the body is stopped by hitting them, the stopping position of the body is not constant.

Therefore, at a position that deviates from the desired stopping position of the controlled object, the content of the next step is determined, for example, by controlling the position of another control axis supported by the controlled object to convey or process the workpiece↓ In such a case, accurate fX, conveyance, and processing will not be possible.

This invention has been made in view of the above-mentioned circumstances, and even if the stop position of the controlled object on the control axis It is an object of the present invention to provide an industrial robot that corrects and executes the deviation by the amount of deviation, and is capable of accurately transporting and processing.

Examples will be described in detail below.

1 is a straight horizontal guide, and this guide 1 has a moving base 2.
is supported, and the position in the X direction is forced by the hydraulic motor Mx.

3 is a horizontal first arm vertically supported on the movable table 2, and is forced to have a turning angle β1 by a hydraulic motor M1.

4 is a horizontal second arm that is vertically supported at the tip of arm 3, and is forced to have a turning angle β2 by a hydraulic motor M2.

Reference numeral 5 denotes a first rotating body vertically supported at the tip of the arm 4, and a rotating angle β3 is forced by a hydraulic motor M3 (not shown).

6 is a vertical arm supported on the rotating body 5, and a hydraulic motor M4
The X direction position is forced.

7 is a gripping means as a first end effector horizontally supported on the lower end of the arm 6, and the rotation angle β4 is controlled by a hydraulic motor M5.
is forced. The claw 7a of the broken gripping means 7 can be opened and closed by a hydraulic cylinder (not shown). 08 is a second rotating body supported coaxially with the rotating body 5, and the rotation angle α1 is forced by an electric motor M11 (not shown). .

A vertically rotating first arm 9 is horizontally supported on the rotating body 8, and is forced to have an elevation angle α2 by an electric motor M12.

10 is a vertically rotating second arm that is horizontally pivoted at the tip of arm 9;
The elevation angle α3 is forced by the electric motor M13.

A third arm 11 is horizontally supported at the tip of the arm 10, and is forced to have an elevation angle α4 by an electric motor M4.

Reference numeral 12 denotes a holder for the second end effector (welding torch), which is supported by the arm 11 and on a shaft perpendicular to the elevation axis of the arm 11, and is forced to rotate at a rotation angle α5 by the electric motor M15. .

As mentioned above, the robot) R is the control axis X, β1, β2, β
3. A parent robot (β-based robot) having 6 degrees of freedom (β4.2) supports a child (α-based robot) having 5 degrees of freedom α1 to α5 in the middle.

It is assumed that each degree of freedom of this robot R is controlled by conventionally known means (for example, a microcomputer) and by a known playback method.

CO3 is a control means (computer) for the β-based robot, and includes IP, CPU β, and memory. The teaching box TBβ, the X-axis servo system, the β1-axis servo system, the β2-axis servo system, the β3-axis servo system, the Z-axis servo system, the β4-axis servo system, and the gripping means 7 are connected to the path line BtJβ of the computer COβ. .

COα is a control means (computer) for α-based robots and includes a CPU α↓ and memory. Computer Co
α's pass line BUα has a teaching pendant TB.
α, welding power source WS, αJ-axis servo system, mirror axis servo system, α
A 3-axis servo system, α4-axis servo system, and α5-axis servo system are connected.

Note that both computers COβ and COα are connected via a known interface.

Furthermore, the operation of this embodiment will be described.

It is assumed that the steel plate W is positioned in a horizontal state in the movement area of the robot 1 by another device (not shown), and the robot R grips the channel material W2 with the gripping means 7, and holds the channel material W2 as shown in FIG. While pressing the steel plate W1 from above, use the torch T to determine the location to be welded.

First, the operator teaches the robot R step by step the work contents in the auto mode using known means.

Now one step of one user program (l:1.2
．． 3.), move the moving platform 2 to another position a distance Xi away from the solid line position in Figure 3 (A), that is, in Figure 3 (A) 2.
There is a command to control the position at the dotted chain line 2 position, and furthermore, in the next step, step (i-1-1), the movable table 2 remains stopped and the rotation angle of the arm 3.4 is changed as shown in FIG. ) The case where there is a command to be controlled as shown by the two-dot chain line will be explained.゛Please refer to Figure 3.5.

(a) It is initially set as ΔXo20 in advance in processing S1.

(b) In process S2, each axis position information (Xi, βJ
l, β20, β3i+ Zi, β4,) from memory c
Incorporate into PUβ.

C. In process S3, the position information of each axis is converted into rectangular coordinates as shown in FIG. 1 (b). That is, (X
i+xi+yi+zi+θi, ψl).

Note that Xi = (k-Xi), where k is a constant 0 for converting the pulse count value of Xl into a distance in the X direction), and in process S4,
i) and the value of command position information X1 are corrected. Note that △X'i
-1 is the X direction calculated by multiplying the difference △X1-1 by a constant k between (i-]:) the stop position information X i -] at the time of teaching of the X axis in Sustera and the stop position information X1-1i1QW at the time of playback. It is distance. That is, the command position information Xi is corrected by the X direction error ΔX1-1 found in the step one step before the l step to be reproduced. This point will become clearer in QI-1 below.

(=]) Then, in process S5, a reproduction command is output to each servo system of the β-system robot based on the one-step information of (Xl, corrected XI + yl + Zl +θ1.ψ1), and the β-system robot controlled.

(v) Then, in process S6, it is assumed that the β-based robot is slightly deviated from the position 2 on the two-dot chain line.

(G) After the position control is completed, in step S7, the difference ΔXi between the X-axis stop position information Xinow at the time of completion and the X-axis stop position information Xi at the time of teaching is calculated as ΔX1−(
Xinow −Xi).

(b) Furthermore, in process S8, the △Xi value is
Convert to directional distance. That is, △Xi2(k・△Xi)
Calculate.

Therefore, the position of the movable table 2 at the time of reproduction deviates from the position at the time of teaching by this distance ΔXi.

Next, in process S9, it is determined whether l is the final step number.

(7,) In this case, it is not the final step, so process S1
In step 0, 1 is updated by one, and the work content after process s2 is repeated.

By the way, even if the turning angle of the arm 3.4 is controlled in accordance with the taught command position information in the next step at the position where the movable table 2 deviates from ΔXi, the position of the gripping means 7 will suddenly differ from the target position. I'm going to try it.

Qli Therefore, after processing S2, the position information of the (1+1) step is taken into the CPU β and then converted to the position in rectangular coordinates (xi+1. xi+1. yi+], zi+
1. θi+1, ψI+]), and further, the command position information
i+1. Based on the position information of θ”1+Q’i+1),
A regeneration command is output to each servo system of the β-system robot. Therefore, the position of the β-type robot is controlled as shown by the solid line in Figure 3 (b). In other words, the position of the tip of the arm 4'' coincides with the position of the tip of the two-dot chain line 4' in FIG. 3 during teaching.

As described above, the difference △X1 between the stop position information X1 at the time of teaching for the X-axis in l step and the stop position information Xinow at the time of reproduction is used for teaching the X direction of the β1 and β2 axes in the (i 10+) step. By adding this to the stop position information Xl at the time, the position of the gripping means 7 is precisely controlled to the target position.

Therefore, if the β-system robot is accurately controlled to the target position, the α-system robot supported by it will naturally be able to perform accurate tack welding.

The aforementioned robot R supports a control axis that can be positioned three-dimensionally on the control axis X. For example, the control axis
It may be possible to support control axes that can be positioned two-dimensionally in only the 1 and β2 axes, or to support control axes that can be positioned two-dimensionally in the X direction and the 0 and perpendicular directions. Furthermore, one control shaft that can be positioned in the same direction as the control shaft X may be supported.

Further, the control axis X may not be a straight line but may be a circle.

Replacement with equivalents constructed by other persons is also included within the technical scope of this invention.

As described above, in this invention, even if the stop position Xinow at the time of playback with respect to the control axis Since the end effector is added to the stop position information Xl during teaching of the other control axes in the X direction, the end effector is precisely controlled to the target position when reproducing the (l+1) step.

[Brief explanation of the drawing]

Each figure shows an embodiment of the present invention, and FIG.
1 is an overall perspective view of the industrial robot, FIG.
Figures (A) and (B) are schematic diagrams for explaining the operation, Figure 4 is a block diagram, and Figure 5 is a flow chart. In the figure, R industrial robot, CO3, C~...respectively control means, 1. Straight horizontal guide, 2. Moving table, 3.
horizontal first arm, 4 horizontal second arm, 5 first rotating body, 6 vertical arm, 7 first end effector (gripping means in the embodiment). Applicant: ShinMaywa Industries Co., Ltd.Continued from page 10 Inventor: Inukai Shinpei Within 1 terre, Takkino-cho, Nishinomiya City0Inventor: Hitoshi Kamei Within 1 terre, Takuno-cho, Nishinomiya City

Claims (1)

[Claims] The control axis X supports two other control axes that can be positioned in the same direction as the control axis, or a plurality of other control axes that can be positioned at least in plane including the X-axis direction, and has position control means for these control axes. In the industrial robot, the control means includes means for calculating a difference ΔXi between stop position information Xi at the time of teaching and stop position information Xi now for the control axis X in one step, and a means for calculating the difference ΔXi. The industrial robot further comprises means for adding ΔXi to stop position information x1+1 during teaching of the other control axis in the X direction in the next step.