JPS6162903A - Control system for robot group - Google Patents

Abstract

PURPOSE:To improve the operation reliability of a robot group and to reduce the cost by detecting the deviation of a work from a position setting reference, and correcting positioning information to be supplied to the group of robots provided successively on a line on the basis of the detected deviation. CONSTITUTION:The robot control system is equipped with a computer 1 for centralized control and also has an auxiliary storage device 2 and an input/ output typewriter 3. Further. this system is equipped with an assembly robot 8a which has a free roller conveyor 10 as a work conveyance system, work fitting device 12, and an error measuring device 7, and sensors 9a-9m which detect the number of a pallet 11 are installed in each assembly station and connected to a digital input/output device 4 together with the output of said error measuring device 7, etc. The sensors 7 measures deviations of the work from two reference positions taught previously at an error measurement station and inputs them to the computer 1. Then, the quantity of correction is calculated by each robot controller on the basis of the pallet number detected by each station and said deviations and the correction is offset.

Description

Detailed Description of the Invention [Technical Field of the Invention] The present invention relates to a robot group management system that performs centralized positioning correction for a group of robots 1 arranged in parallel on an automatic assembly (or processing) line. .

[Technical background of the invention and its problems] In what is called an industrial robot, route and position information is programmed and memorized in advance through teaching or other methods. , some perform the same operation and positioning repeatedly. For example, when considering an automatic MRR line, the target workpiece is attached to jig barres 1 to 1 and flown on a conveyor, and after positioning the jig at each work station, each robot 1
- is designed to perform assembly work according to a pre-given program. In this case, the above program actually teaches the installation of the reference workpiece (the reference jig is pulled!).

In the above case, in general, due to variations in the work itself, ■ variations in the jig pallet 1, and ■ variations in the attachment of the work to the jig pallets 1 to 1, teaching A positional error occurs between the reference workpiece attached to the used reference jig pallet and the other workpieces in A.

Therefore, in operations that require precision and have small tolerances, such as inserting a bottle into a hole in a workpiece, it often happens that even if the robots 1~ position the bottle as instructed, the hole position is misaligned and the bottle cannot be inserted.

Conventionally, as a method for correcting the above-mentioned positional errors, which are mainly errors on the Equipped with a measuring device that measures the error of the workpiece using a position measuring sensor,
The deviation from the reference workpiece used for teaching was measured, and the position information in the program stored in the robot itself was corrected so that the target workpiece was positioned in accordance with the position information.

However, in phase 9 lines, etc., multiple robots, from a few to as many as 20 or more robots, are installed on the side of the assembly conveyor line, and work is often carried out sequentially according to the assembly process of the workpieces. Even in such a case, there are various disadvantages in having each robot have the above-mentioned measuring device and correction function.

That is, providing a sensor for error measurement at the tip (grip portion) of each robot poses the following problems.

■ There is no space to install some sensor heads.

As an attachment for assembly, for example, a nut runner,
When installing an air hammer, etc., there is often no space to install the sensor, or even if there is, it will interfere with the assembly operation.

■ Attaching the sensor head increases the weight.

If the robot's payload limit is met or not, the inertia increases, affecting positioning at 11 degrees/hour.

■ The overall cost will increase significantly.

In addition to the sensor head, a device that converts the data (offset amount) that can be corrected by the robot i- and transmits it to the robot controller 1 to the rollers is also required, so as the number of robots increases, the overall cost will increase significantly. I will do it.

[Object of the Invention] The present invention has been made based on the above circumstances, and its purpose is to
By centrally measuring and managing the positional deviation of the workpiece to be mounted due to variations in the position of the robot, it is possible to improve the reliability of the work of the group of robots and reduce the number of defects. The objective is to provide a group management system.

[Summary of the Invention] In order to achieve the above object, the robot 1 to group management system according to the present invention includes a detection means installed at the head of an automatic assembly (or processing) line to detect deviation of the workpiece from the position setting standard. and a correction means for correcting the positioning information given to the group of O-bots arranged in parallel on the line based on the output from the detection means.

[Embodiment of the Invention] A robot group management system according to the present invention will be described below according to an embodiment shown in FIG.

FIG. 1 is a configuration diagram of an engine assembly line as an example. In Figure 1, 1 is a computer for centralized management,
This computer 1 is connected to an auxiliary storage M2 and an input/output typewriter 3. In addition, there is a free flow conveyor 10 as a workpiece conveyance system, a workpiece mounting device 12 is installed at the first station of the assembly line, and an assembly robot 8a having an error measuring device 7 in its head is installed at the next station. There is. 7 is an error measuring device, and this error measuring device 7 is connected to the digital input/output interior @4 via the measurement data controller 6.

The stations from the first station onwards are the actual assembly line, and on the side of the conveyor 10 there are assembly robots 8b, 8c, . . . at each station.
, 8...J3n are installed, and the controllers of these robots are each connected to the serial transmission interface 5.

Additionally, each assembly station has pallet number sensors 98, 911. ....

9m are installed, and these are connected to digital input/output equipment -〇-4. Further, the digital input/output interior W4 and the serial transmission interface 5 are connected to the g1K111 and integrated with the IT failure system. In addition,
110.11a, 1 lb, 11c, -, 11m.

11n is a workpiece mounting pallet, and 12 is a workpiece mounting device.

Next, the operation of this embodiment having the above configuration will be explained with reference to FIGS. 2(a) and 3(b) and FIG. In FIGS. 2(a) and (b), 13 is a jig pallet, 14 is a workpiece,
P+o and P2o are dowel holes provided in the workpiece 14.

First, the reference work 14 to be taught is mounted on the jig pallet 1-13 in Fig. 2 (a) and (b) using the work mounting device @12.
and send it to the measuring station.

Two reference points of the workpiece positioned at the measurement station, namely, dowel holes P10 and P2O, are taught.

At the following assembly stations, the jig 5let 13 that has been taken from the reference work 14 is positioned at a fixed point on the conveyor 101-, and then the assembly work at that station is taught. Repeat until the end.

The above is the preparation work for teaching the assembly robot.

Next, a description will be given of the operation of conveying the workpieces to be assembled onto the conveyor 10. The attachment of the workpiece to the jig pallet 1- is the same as that for the reference pallet.

At the next error measurement station, the sensor 7 measures how much error the workpiece to be sent to the assembly line has with respect to the two previously taught reference positions (Plo, P2O). Each error between reference point P1[1 and reference point P20 is Δ×1. Δy1 and Δ×2. △
y2 is digitized by the measurement controller 6 and transmitted to the computer 1 via the digital input/output device 4.

At this time, the pallet number sensor 9a,
9b, . . . , 9m and transmitted to the calculation I11 via the digital input/output device 4.

Then, in the pupil meter 1, as shown in Fig. 3, the error of the workpiece is converted into a rotation error Δθ such as a translation error Δ×1°Δy1 on the X-Y plane, and is paired with the pallet NO. Create a table and memorize it.

In FIG. 3, Pl[+, P20 is the teaching point I~ of the reference work, and P+ 1. P2+ is the measurement point of the workpiece], and P22 is the movement point 1~ of the second reference point P21 when the first reference point of the workpiece is translated in parallel to the first reference point of the reference workpiece. X, Y
is the relative position of the second reference point when the first reference point is the origin, is a value determined by the machine, and is input into the computer 1 in advance.

At the measuring station, errors are measured in the same manner as described above for the works mounted on the jig pallets that are brought in one after another, the signals are converted, and the table as described above is created and stored.

At the assembly station, if the robot operates on a workpiece with an error as instructed, the assembly work will not be performed properly. Therefore, the computer 1 is informed of the pallets 1 to NO detected at the station, and the computer 1 is informed of the error of the workpiece.

Each robot 1-controller of the robots 8a, 8b, . ΔV1. Calculate how much correction is needed at your work point based on 80, and move the correction by offset.

As described above, according to this embodiment, the teaching data of the robot group at each work point l~ is individually corrected based on the overall error data so that the robot group performs normal operations. Therefore, ■ The reliability of assembly work is improved. In particular, tightening errors, insertion errors, etc. can be significantly reduced.

(2) By sharing the error measurement data at one location, the system is simplified and costs are reduced compared to the case where each O-Bot 1 is measured.

■ Since there is no need to attach sensors to each robot, small, portable robots can be used, and losses can be reduced by 1 or more.

The present invention is not limited to the above embodiments, but may be modified and implemented as described below. That is, (1) the measurement error table may not be stored in the computer, but may be immediately transmitted to the robot controller each time an error is measured and stored on the robot controller.

■ As long as the line uses multiple robots, it is not limited to an assembly line.

■ The conveyance system may be other than a conveyor.

■ The configuration of the 11-frame machine 1 will not change even if the system is changed as appropriate.

■ Correspondence between pallets and error data may be achieved using a tracking management method without using pallet numbers.

The present invention is not limited to the above-mentioned embodiments, but can be implemented with various modifications without departing from the gist thereof.

[Effects of the Invention] As described above, according to the present invention, a detecting means installed at the head of an automatic assembly (or processing) line to detect the deviation of the workpiece from the position setting standard and a detecting means installed in parallel on the line. Equipped with a correction means that corrects the positioning information given to the robot group based on the output from the detection means, it is possible to centrally measure the positional deviation of the mounted workpiece at one location due to variations in the workpiece, mounting jig pallet, mounting method, etc. Therefore, it is possible to provide a robot group management system that improves the reliability of the robot group's work and reduces costs.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the robot group management system according to the present invention, and FIG. ) is a top view, FIG. 2(b) is a front view, and FIG. 3 is a diagram for explaining the error of the workpiece on the XY plane. 1... Computer, 2... Auxiliary storage device, 3... Input/output typewriter, 4... Digital input/output 81.5.
... Serial transmission interface, 6... Measurement data controller, 7... Error measuring device, 8 a, 8
b, 8c. ..., 8m, 8n...robot, 9a, 9b,...
・, 9m... Pallet number sensor, 10... Free 70-conveyor, 110.11a, 1 lb, 11
c,... 11m, 11n... Workpiece mounting pallet,
12... Workpiece mounting device, 13... Jig pallet ~
, 14... Work. Applicant's agent Patent attorney Takehiko Suzue No. 17 Figure 2 (a) Figure 3 Y sleeve

Claims (1)

[Claims] A group of robots are installed in parallel on an automatic assembly (or processing) line and sequentially perform predetermined assembly (or processing) work on the workpieces being transported on the line, and a group of robots is installed at the beginning of the line and is installed at the beginning of the line to perform predetermined assembly (or processing) work on the workpieces transported on the line. A robot group management system comprising: a detection means for detecting a deviation; and a correction means for correcting positioning information given to the robot group based on an output from the detection means.