JPH04271408A - Offline direct teaching device for 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]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a teaching device for industrial robots.

0002

2. Description of the Related Art Conventional teaching devices for industrial robots include: (1) A teaching box is used to move a robot to a target position and teach its position and orientation. ■ The operating end of the robot is held manually,
This will teach you how to move it and actually do work. (2) A teaching-only manipulator that has the same or similar shape as the reproducing robot and does not have a drive system is used, and the manipulator is manually operated to teach the movement locus (see, for example, Japanese Utility Model Publication No. 58-21663). Three ways were common.

0003

[Problems to be Solved by the Invention] The above systems each have the following problems. In other words, if the motion you want to teach is a smooth spatial continuous curve and the wrist posture changes in a complicated manner, the above method (2) requires teaching point by point at a fine pitch, which requires a huge amount of time. There is a problem that teaching time is required. In addition, in the methods (2) and (3), there is a problem in operability due to the restriction that the robot has the same shape as a robot with a drive system, so it is difficult to obtain the desired motion trajectory.

On the other hand, Japanese Patent Laid-Open No. 59-173805 describes a robot that operates based on motion data in a coordinate system whose origin is a reference point set at an arbitrary spatial position. In what is described in this publication, the master robot and slave robot have the same shape, and cannot be applied to robots of different models.

Furthermore, Japanese Patent Laid-Open No. 63-259703 discloses that in order to make robots with different shapes operate using teaching data, the teaching data of a previously used robot of another model can be used to teach a new robot. It is described that the data is converted within the control device.

However, in any of the above-mentioned conventional techniques, it has not been possible to teach using a dedicated teaching machine with a mechanical shape different from that of the robot that performs the work. Therefore, an object of the present invention is to provide a teaching device that can directly teach operations using a teaching device that has a mechanical shape different from that of an actual working robot.

[0007]

[Means for Solving the Problems] The present invention provides an off-line direct system for teaching robots to operate based on motion data in a coordinate system whose origin is a reference point set at an arbitrary spatial position. The teaching device has a mechanical shape different from that of the robot, and is equipped with a displacement detector for detecting displacement of each movable part, and a teacher holds the tip of the movable part to teach the robot the actual work operation. A reference point set at an arbitrary spatial position with respect to the direct teaching mechanism is set as the origin based on the output signal of the displacement detector of each movable part and the mechanical constant of the direct teaching mechanism. and data processing means for determining and storing the motion in the coordinate system.

[0008]

[Operation] The device of the present invention, as shown in its basic configuration in FIG. 1, includes a direct teaching mechanism 1 for teaching,
It consists of a displacement detector 2 that detects the displacement of each movable part, and a data processing means 3 that stores and converts the detected displacement information. The direct teaching mechanism 1 for teaching is
It shall be possible to easily operate it manually so as to obtain the desired trajectory even with smooth spatial continuous curves and complex posture changes. Sampling from the displacement detector 2 to the data processing means 3 is performed at an arbitrary minimum time, so that it is possible to sufficiently follow sudden changes in the teaching operation.

[0009] In the teaching device configured as above,
Using the direct teaching mechanism 1, set an arbitrary point in space as a reference point, teach the other two points (these three points are not on a straight line), set the X-Y plane, and
- By setting the Z axis perpendicular to the Y plane, the coordinate system in the direct teaching mechanism 1 is determined. Next, a teaching operation is performed using this direct teaching mechanism 1. The data processing means 3 arbitrarily samples the displacement data of the direct teaching mechanism 1 detected by the displacement detector 2 so as to be suitable for the work operation, and furthermore, so that it can be reproduced by an arbitrary robot (not shown). Convert to Cartesian coordinate system data.

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below with reference to embodiments shown in the drawings. FIG. 2 is a configuration diagram of an embodiment of the present invention. In the figure, the teaching manipulator 4 includes a balancer (balance weight to reduce the teacher's effort), parallel links, wrist inline (
It has a mechanism in which the wrist is not offset. An absolute encoder 2 that detects the position (angle) is attached to each axis of the manipulator 4.
Connected to interface 5. Two foot switches are prepared as start switches for sampling position data: foot switch 6 is for continuous sampling, which always takes in position data when it is on, and foot switch 7 is for continuous sampling, which takes in position data when on/off. It is used for one-time sampling to capture position data. Note that the sampling period may be set arbitrarily from the operation panel 11 or the like. This starts sampling, and the obtained position data is temporarily sent to the interface 5. The interface 5 transmits position data according to commands from the personal computer 8. The personal computer 8 stores the received position data, extracts only necessary trajectory points (which may not include all teaching points), and converts them into orthogonal data. Orthogonal data is robot controller 9
is sent to , and performs conversion according to the manipulator mechanism. This makes it possible for the robot 10 to obtain the desired motion trajectory.

The present invention will be explained based on the drawings, taking a polishing operation as an example. In FIGS. 3 and 4, a workpiece (workpiece) 21 is supported by a workpiece support portion 22 rotatably provided on a hand 23 that can arbitrarily select a surface to be polished by a polishing machine 38. This work support part 22 is assembled to a link 24, and the rotation axis of the link 24 extends substantially vertically, and the link 24 has a rotation axis in the horizontal direction.
It is orthogonally connected to 5. The sixth axis position detector 26 communicates with the link 24 via a belt (not shown), and the fifth axis
The shaft position detector 27 is directly connected to the link 25. The horizontal arm 28 has a rotation axis perpendicular to the rotation axis of the link 25, and this rotation axis substantially intersects with the rotation axis of the link 24. The fourth axis position detector 29 is connected to the rotating shaft of the horizontal arm 28 via a belt. The link 30 has a rotation axis perpendicular to the rotation axis of the horizontal arm 28, and freely rotates the horizontal arm 28. A balance weight 32 is attached to the horizontal arm 28 to maintain the posture of the link 30 around the rotation axis and the link 25 around the rotation axis. The rotation axis of the link 25 and the rotation axis of the balance weight 32 are in communication via a belt. The balance weight 32 can be selectively assembled according to the weight of the workpiece, can slide on a shaft extending in the radial direction from the center of rotation, can be fixed at any position, and can finely adjust the balance. The third axis position detector 31 is in communication with the rotation axis of the link 30 via a belt. The height of the horizontal arm 28 and the link 30 from the bottom surface of the base 37 is approximately the height of the worker's waist, improving work efficiency. The arm 33 has a horizontal parallel link structure, and has one of four rotation axes.
A position detector 34 for the second axis is attached at this location.

The arm 35 also has a horizontal parallel link structure,
A position detector 36 for the first axis is installed at one of the four rotation axes.
The contact is through the belt. By making the arms 33 and 35 parallel links, the horizontal arm 28 can always maintain a constant angle between the polishing surface of the polishing machine 38 and the polishing surface of the workpiece, which makes it possible to detect the first and second axes. The influence of the deviation in precision is less likely to occur on the precision between the workpiece and the polished surface, and the polished surface can be processed well. The bearing preload for each of the 1st to 6th axes can be adjusted from the outside, thereby optimizing the resistance of the 6 axes.
The teaching manipulator 4 can be moved as intended by the operator. The above is the configuration of the main body of the teaching manipulator 4.

FIG. 5 is a block diagram of the control system of this embodiment. Position detectors (absolute encoders) 26 and 27 for each axis of the teaching manipulator 4
, 29, 31, 34, and 36 are taken into the interface 5. The work file number, work start/end commands, sampling period, etc. are displayed on the operation panel 11.
can be input through the interface 5. Two types of foot switches are used as position data sampling start switches: foot switch 6 is for continuous sampling, which always captures position data when it is on, and foot switch 7 samples only once when turned on. It is used for this purpose. By employing the operation panel 11 and the foot switches 6 and 7, the operator can change the necessary modes and collect data continuously while being present during teaching.

Prior to the work, the workpiece 21 is attached to the workpiece support section 22 shown in FIG.
In order to reduce the error, one point near the polisher 38 is set as a reference point. If you move the workpiece 21 to the next arbitrary point and another point (these three points are not on a straight line) and import the coordinates of that point, the X-Y plane is defined, and furthermore, on that X-Y plane, A Z-axis is defined as a vertical axis. This defines a reference coordinate system. Next, perform teaching work. The data sampled during the teaching work is once sent to the conversion/storage device (personal computer) 8 via the interface 5. All data received by the personal computer 8 is stored once, and necessary data is extracted from it and converted into orthogonal data on the coordinate space defined before the teaching work. Converted,
The stored orthogonal data is sent to the robot controller 9.
It can be input through transmission or storage media and reproduced on the robot 10 side in a predefined coordinate space. With the above teaching procedure, the robot can perform grinding work.

[0015]

Effects of the Invention As described above, according to the present invention, the direct teaching mechanism can have a shape different from that of the robot that actually operates. However, teaching can be performed even when the robot is not in use, and it can be realized in a type that is convenient for the work. For example, even if the robot that is actually operated is a general vertical multi-joint type, the direct teaching mechanism can be realized as a horizontal multi-joint type.

[0016] Furthermore, if input data is stored in the robot using a storage medium, it is possible to teach a plurality of robots using one storage medium. Furthermore, since it is based on motion data in a coordinate system whose origin is a reference point set at an arbitrary spatial position, deviations in the installation of the robot that performs the actual work are irrelevant.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of a teaching device according to the present invention.

FIG. 2 is a schematic diagram of an embodiment of the invention.

FIG. 3 is a plan view showing another embodiment of the present invention.

FIG. 4 is a front view showing another embodiment of the present invention.

FIG. 5 is a block diagram of a control system according to an embodiment of the present invention.

[Explanation of symbols]

1 Direct teaching mechanism 2 Displacement detector (absolute encoder) 3
Data processing means 4 Teaching manipulator 5 Interfaces 6, 7 Foot switch 8 Personal computer 9 Robot controller 10 Robot 11 Operation panel 21 Work 22 Work support 23 Hands 24, 25, 30 Link 26 Sixth axis position detector 27 Fifth axis Position detector 28 Horizontal arm 29 Fourth axis position detector 31 Third axis position detector 32 Balance weights 33, 35 Arm 34 Second axis position detector 36 First axis position detector 37 Belt 38 Polishing machine

Claims (1)

[Claims] 1. An offline direct teaching device for a robot that teaches movements to a robot that operates based on movement data in a coordinate system whose origin is a reference point set at an arbitrary spatial position. The direct robot has a different mechanism shape and is equipped with a displacement detector that detects the displacement of each movable part, and the instructor holds the tip of the movable part to teach the robot the actual operation.
A coordinate system whose origin is a reference point set at an arbitrary spatial position with respect to the direct teaching mechanism based on the output signals of the displacement detector of the teaching mechanism and each of the movable parts and the mechanical constants of the direct teaching mechanism. An off-line direct teaching device for robots comprising a data processing means for determining and memorizing the motions of robots.