JPS60246407A - Follow-up type robot device - Google Patents

Abstract

PURPOSE:To attach, detach and assemble, etc. parts with respect to a rotary table without making the rotary table stand still, by making a work head of a robot follow up by a circular interpolation so as to synchronize with a rotation of the rotary table. CONSTITUTION:When a counter PDC of a memory 36 is reset by following an operation of an original point detector 14, thereafter, the servo-computer 32 compares a value set to a set area DSA of the memory 36, and the contents of PDC for detecting a table rotational angle based on an original point position as a reference. When both of them coincide, an interrupting signal is sent out to a central processor 30, and by this interrupting signal, the central processor 30 commands a follow-up movement of a robot 20 to a servocomputer 33. Based on it, a work head 25 of the robot 20 is moved by synchronizing with part W1 on a rotary table 10 by a circular interpolation between points taught by each joint in advance.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a robot device that attaches and detaches parts by following a continuously rotating rotary table.

<Prior Art> In general, when a robot grasps a part placed on a rotatable rotary table or assembles another part onto that part, it is conventionally necessary to keep the rotary table stationary. After the robot completes a predetermined work, the rotary table is indexed by one pitch rotation.

However, if there are special circumstances such as grinding parts using the rotation of a part of the rotary table, the rotary table cannot be kept stationary, so while the rotary table is rotating, It is necessary to enable robots to attach, detach, and assemble parts, and this is also effective in reducing takt time.

<Object of the Invention> An object of the present invention is to enable a robot to follow the rotation of a rotary table to attach and detach parts without stopping the rotation of the rotary table.

<Structure of the Invention> In order to achieve the above-mentioned object, the present invention disposes a robot corresponding to a rotary table on which a plurality of jigs for holding workpieces are installed at intervals in the circumferential direction. A storage means is provided for storing the rotation center position of the rotary table and the rotation radius of the workpiece in coordinates based on the robot, and also for storing position data of the point at which the work of the work head of the robot is taught, and the jig on the rotary table is provided. After it is detected that the robot has passed a certain point, the robot performs a follow-up operation by performing circular interpolation between the instructed points along a circular trajectory centered on the rotation center position of the rotary table. The device is equipped with an operation control means for controlling the operation.

With this configuration, the robot's work throat follows the taught points by circular interpolation in synchronization with the rotation of the rotary table, and the robot can attach, detach, or assemble the workpiece while the rotary table is rotating. Become so.

<Example> Embodiments of the present invention will be described below based on the drawings.

In FIG. 1, reference numeral 10 indicates a rotary table that is rotatably supported in a horizontal plane on a concave support base, and a plurality of jigs 11 are installed on the rotary table 10 at equal angular intervals on the circumference. , on these jigs 11 a component W1 is attached. The rotary table 10 is continuously rotated at a predetermined speed by a servo motor 12 shown in FIG. 2, and the rotation angle of the rotary table 100 is detected by an encoder 13 connected to the output shaft of the servo motor 12. . An origin detector 14 for detecting that each of the jigs 11 has passed the reference origin is fixed on the support base, and a dog 15 for operating the origin detector 14 is attached to each jig 11.

20 indicates a horizontally articulated robot, and this Roposo) 2
0 are arranged corresponding to the outer periphery of the rotary table 10. The daring robot 2° includes a trunk 22 that is supported by a fixed base 21 in a vertically movable manner.
The first arm 23 is horizontally pivotably supported on the 17th arm.
- A second arm 24 is pivotably supported at the tip of the g142 arm 23 so as to be horizontally rotatable, and a working gutter 25 is attached to the tip of the g142 arm 24.

Next, the control device for the rotary table 1o and the robot 7) 20 will be explained based on FIG. A servo computer 32 that drives the servo motor 12 for driving the table, a servo computer 33 that drives the circumferential servo motors M1 to M3 of the robot 2o, and an operation panel 3 that instructs teaching points, etc.
4 is connected.

The memory 31 is provided with a storage area A1 that stores data on the positioning point of the work head 25 of the robot 20 in orthogonal coordinate values, and in the teaching mode, the rotary table 1o is stopped at a predetermined angular position. In this state, position the robot 2o at the set teaching position and move it to the starting point P1.
data is stored in the storage area AI of the memory 31, and in this state, the required teaching operation is performed while manually rotating the rotary table 10, and the data at each teaching position is stored in the storage area AI. .

The memory 31 also has a storage area that stores the center position ffo+ of the rotary table 1o in coordinates based on the robot position, as well as the rotation radius R of the workpiece on the rotary table 1o, the angular pitch P of the workpiece, etc. A2
is provided.

Further, the servo computer 32 is connected to the encoder 1.
It has a function of counting the output pulses from 3 and detecting the angular position of the rotary table 10.

That is, the memory 3 connected to the servo computer 32
6 is formed with a counter PDC for position detection,
The servo computer 32 resets the counter PDC to zero when the origin detection signal is output from the origin detector 14, and thereafter increments the counter PDC every time a pulse is output from the encoder 13 to determine the angular position of the counter PDC. Detect. The memory 36 also includes the robot 2
Setting area DS for setting the starting position of zero tracking operation
A is formed, and the servo computer 32 selects the setting area DS based on command data from the central processing unit 30.
Position data is set in A, and when the count value of the counter PDC becomes equal to the value of this setting area DSA, an interrupt is issued to the central processing unit 30.

Next, the operation of the servo computers 32, 33 will be explained based on the flowcharts shown in FIGS. 3 and 4.

When the origin detector 14 is activated by the dog 15 attached to the jig 11 while the rotary table 10 is being rotated at a predetermined rotational speed by the servo motor 12 (
After step 50), the counter PDC detects the table rotation angle based on the origin position. However, during this lever, the working head 25 of the robot 20 is taught the starting point P
1, and at that position it enters a standby state until an interrupt signal is sent from the central processing unit 30, as will be described later.

When the counter PDC of the memory 36 is reset to zero due to the operation of the origin detector 14, the servo computer 32 then compares the value set in the setting area DSA of the memory 36 with the contents of the counter PDC (step 52).
), when both coincide, that is, when the rotary table 10 is rotated to an angular position where the center of the part W1 on the rotary table 10 coincides with the teaching position at which the work head 25 of the robot 20 is positioned, the central processing unit 30 An interrupt signal is sent (step 53).

Based on this interrupt signal, the central processing unit 30 instructs the servo computer 33 to follow the movement of the robot 20 (step 54), and based on this command, the work head 2 of the robot 20
5 is moved in synchronization with the part W1 on the rotary table 10 by circular interpolation between points taught in advance at the nodes.

Below, as shown in FIGS. 4 and 5, the following motion of the robot 20 is as follows. As shown in FIG. 4 and FIG.
An example of charging 2 will be explained.

As described above, when the following movement of the robot 20 is commanded in step 54, the rotational speed Vt of the rotary table 10 is first calculated based on the output of the encoder 13 (step 55), and then the rotation speed Vt of the rotary table 10 is calculated based on the output of the encoder 13 (step 55). Based on the coordinate values of the end point P2, the amount l of movement of the work head 25 of the robot 20 along an arcuate trajectory passing through the center of the workpiece in synchronization with the rotation of the rotary table 10 is determined, and
The moving speed Vr is determined by the following formula (step 56
).

Vr= (■GoT1cho)・V, t/j! Here, d is the vertical distance between the starting point P1 and the ending point P2.

In this way, the working head 25 of the robot 20 is moved at a speed of V
Conversion to polar coordinates is performed in order to move from the starting point P1 to the ending point P2 along a circular arc trajectory with radius R at r (step 57
), L, circular interpolation is performed based on this conversion data (Step 57), and the work head 25 of the Roposo 20 moves the part W2 to be assembled onto the part W1 while following the rotation of the rotary table 10. Perform charging operation.

As a result, even if the rotary table 10 cannot be stopped because the workpiece W is being ground on a part of the rotary table 10, parts can be attached, detached, assembled, etc. while the rotary table 10 is rotating. Moreover, since the robot 20 can perform the work without making the rotary table 10 stand still, the takt time can be shortened.

In the embodiment described above, the table rotation speed Vt is calculated from the output of the encoder 13 connected to the rotary table 10, and the follow-up speed of the robot 20 is determined based on this. Although there is an advantage that the robot 20 can perform a follow-up operation in response to a change in the rotation table, it is also possible to drive the rotary table at a constant commanded speed and determine the follow-up speed of the robot based on the command value.

Further, in the above embodiment, a simple example is shown in which the robot 20 performs circular interpolation on the robot 20 along the rotation locus of the component W1, but the work head 25 may
It is also possible to follow the rotary table 10 while moving it in the radial direction.

<Effects of the Invention> As described above, according to the present invention, the work head of the robot is made to follow the rotation of the rotary table by circular interpolation in synchronization with the rotation of the rotary table. This has the effect of allowing parts to be attached/detached or assembled.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention; FIG. 1 is a plan view showing the relationship between the rotary table and the robot, FIG. 2 is a block diagram showing the configuration of the control circuit, and FIGS. 3 and 4 are flowcharts. The figures shown in FIGS. 5 and 6 are diagrams showing the movement path of the working head of the robot. 10...Rotary table, 11...Jig, 14...
Origin detector, 20... Robot, 25... Work head, 30... Central processing unit, 31... Memory, 32
．． 33... Servo computer. Patent applicant Toyota Machinery Co., Ltd. Figure 2

Claims (1)

[Claims] (11) A robot is disposed corresponding to a rotary table on which a plurality of jigs for holding workpieces are installed at intervals in the circumferential direction, and the work head of the robot is synchronized with the rotation of the rotary table by a driving means. A tracking type robot device that performs work such as attachment/detachment or assembly by following the movement of the robot, which stores the rotation center of the rotary table and the rotation radius of the workpiece in coordinates based on the robot, and also stores the rotation center of the rotary table and the rotation radius of the workpiece in coordinates based on the robot. storage means for storing positional data of the point at which the work was taught, and a jig on the rotary table,
a detection means for detecting that the robot has passed a certain point; and after detection by the detection means, the work head of the robot is moved between the taught points in a circular arc centered on the rotation center position of the rotary table. A tracking robot device comprising a motion control means that performs a tracking motion by performing circular interpolation along a trajectory.