JPH0690648B2 - Direct teaching robot - Google Patents

Description

TECHNICAL FIELD The present invention relates to direct teaching of a direct drive robot in which a prime mover and an arm are directly connected.

2. Description of the Related Art In recent years, direct drive robots have begun to appear in industrial robots for the purpose of speeding up, etc., and it is possible to perform direct teaching in which a person directly moves a robot arm for teaching. Came.

An example of the conventional direct display method described above will be described below with reference to the drawings.

FIG. 3 shows a control block diagram for performing conventional direct teaching. 1 is a control unit, 2 is a position command signal output from the control unit, 3 is a position feedback signal,
4 is a position deviation amplifier, 8 is a speed deviation amplifier, and a speed command value
The error between 18 and velocity feedback value 21 is amplified. Reference numeral 10 is a current control unit which inputs a current command value 9 and outputs a modulation signal 11, 12 is a power amplifier, 13 is a motor, 14 is a speed sensor directly connected to the motor 13, and 15 is a position also directly connected to the motor 13. It is a sensor. Reference numeral 33 is for direct teaching by freeing the motor 13, which is a motor power OFF SW for turning off the voltage application to the motor 13.

A conventional direct teaching method configured as above will be described.

First, at the time of direct teaching, the motor power OFF SW33 is set so that no voltage is applied to the motor 13. In this state, since the motor 13 does not generate torque, the motor 13 becomes free, and since the motor and the arm are directly connected and there is almost no friction or the like, the arm of the robot is moved and positioned by a light external force. When the arm is moved, the motor 13 rotates, and the position feedback signal 3 corresponding to the rotation of the motor 13 is generated by the position sensor 15 directly connected to the motor 13 and input to the control unit 1. In response to the instruction of the teaching point, the control unit 1 stores the point as the teaching point. Here, the position deviation amplifier 4, the speed deviation amplifier 8, the current controller 10 and the power amplifier 12 operate and switch, but since the motor power OFF switch 33 is finally turned off, no voltage is applied to the motor 13. Therefore, the arm of the robot can be moved to the positioning point with a light external force.

Problems to be Solved by the Invention However, in the above-mentioned configuration, although the movement is light during direct teaching, the inertial force of the arm or the like tries to continue the movement even after the force is stopped and the fine position is kept. And it was difficult to teach the route.

In view of the above problems, the present invention, in direct teaching, applies viscous resistance by speed feedback to prevent an arm or the like from continuing to move after stopping applying force, and teaching of a fine position or path is possible. The present invention provides a direct teaching robot.

Means for Solving Problems In order to solve the above problems, the direct teaching robot of the present invention has a means for setting a speed command value to a fixed value irrespective of a position command value or a position feedback value and a speed feedback gain variable. It is equipped with a means to

Operation The present invention has the above-mentioned configuration,
It is possible to teach a fine position and path by applying only the velocity feedback and giving a suitable viscous resistance to the robot arm, and the teaching work can be easily realized.

Embodiment A teaching method of a direct teaching robot according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of a direct teaching method according to an embodiment of the present invention, and FIG. 2 is a configuration diagram of a robot body. In FIG. 1, 5 is a position deviation output switching unit, 16 is a fixed speed command value, and 17 is a speed feedback gain variable unit.

The operation of the direct teaching method configured as described above will be described below with reference to FIGS. 1 and 2.

The position command value 2 output from the controller 1 and the position deviation output 18, which is the output of the position deviation amplifier 4 that amplifies the deviation by the position feedback 3, are connected to the a terminal of the changeover switch 5. On the other hand, the speed command value 16 at the time of teaching is connected to the terminal b of the changeover switch 5. On the other hand, both the position feedback value 3 and the speed feedback value 7 are input to the control unit 1.

When performing direct display, the control unit 1 first outputs the changeover signal 19 and the changeover switch 5 outputs the speed command value 6 to the position deviation.
It is separated from 18, connected to the set fixed speed command value 16 and input to the speed deviation amplifier 8 (terminal b).

Directly taught, the motor 13 rotates,
The speed information 21 of the speed sensor 14 directly connected to 13 is input to the speed feedback gain varying unit 17 and the speed feedback gain switching signal 20 output from the control unit 1 causes the speed feedback gain varying unit 17 to move to the speed sensor 14
The speed feedback value 7 corresponding to the rotation speed of the motor 13 is input to the speed deviation amplifier 8 by amplifying the magnitude of the speed information 21 of FIG. Here, the speed feedback gain variable section
The reason that 17 amplifies the size of the speed information 21 of the speed sensor 14 is to make the speed feedback value 7 suitable for the size of the fixed speed command value 16. However, even if it says "amplification", unless the speed sensor 14 has a very small measurement dimension, it will be reduced and multiplied. The speed amplifier 8 amplifies the error between the fixed speed command value 16 and the speed feedback value 7, and outputs the current command value 9 to the current control unit 10. Further, the current control unit 10 outputs a modulation signal 11 to the power amplifier 12, applies a current to the motor 13, generates a torque in the opposite direction to the teaching according to the teaching speed, and generates a resistance corresponding to the speed, that is, a viscous resistance. give.

At the time of reproduction operation, the control unit 1 outputs the switching signal 19,
Change the speed command value 6 to the fixed speed command value by the changeover switch 5.
It is separated from 16, connected to the position deviation output 18, and input to the speed deviation amplifier 8 (a terminal). When the position command value 2 is output from the control unit 1, the difference between the position command value 2 and the position feedback 3 is amplified by the position deviation amplifying unit 4 and becomes a position deviation output signal 18. Speed command value 6 via changeover switch 5
And the difference between the speed feedback value 7 and the speed feedback value 7 are input to the speed deviation amplifier 8. The speed deviation amplification unit 8 performs amplification,
The current command value 9 is output to the current control unit 10. Further, the current control unit 10 outputs a modulation signal 11 to the power amplifier 12 and supplies a current to the motor 13 so that the motor reaches a position according to the position command. At this time, the speed feedback gain varying unit 17 operates the speed feedback switching signal 20
Thus, the value is set to a value suitable for performing the reproducing operation.

As shown above, the position deviation output signal 18
Is completely separated, and the fixed speed command value 16 and the speed feedback value 7 corresponding to the rotation speed of the motor 13 are subtracted and amplified to generate a torque in the direction opposite to the rotation direction of the motor 13 to generate a viscous resistance force. Since it is possible to control overshooting due to inertial force of the robot arm or the like, it is possible to easily teach a fine position or path. Further, during the reproducing operation, the positioning can be performed as in the conventional case. Fixed speed command value 16
Can be set with a variable resistor. However, when the force due to gravity etc. is not applied in the radial direction of the electric motor like the first electric motor 23 and the second electric motor 26 in the configuration diagram of the robot body in FIG. Set to OV, linear motor 31
In the electric motor to which force is applied as described above, it is for generating a torque that balances gravity and the like for the purpose of compensating gravity and the like.

Although the fixed speed command value 16 is represented by the variable resistor in FIG. 1, it may be set by the controller 1 by the D / A converter.

Further, the switching signals 19 and 20 may simply be command execution flags when the control unit 1 performs soft processing on the position deviation amplifier and the speed deviation amplifier.

Further, the position sensor 15 and the speed sensor 14 may be the same sensor.

As described above, the present invention separates the speed command value from the position deviation output when performing direct teaching, combines the fixed speed command value with the fixed speed command value, and sets the fixed speed command value as an offset to the motor according to the change of the speed feedback value. By changing the magnitude of the electric current to be generated and generating a torque in the direction opposite to the display direction to give an appropriate viscous resistance, it is possible to easily teach the fine position and path in direct teaching to the robot arm. it can.

[Brief description of drawings]

FIG. 1 is a control block diagram of a direct teaching robot according to an embodiment of the present invention, FIG. 2 is a perspective view of a main body of the robot of the same embodiment, and FIG. 3 is a control block diagram of a conventional robot. 1 ... Control unit, 4 ... Position deviation amplifier, 5 ... Changeover switch, 8 ... Speed deviation amplifier, 16 ... Fixed speed command value,
17 …… Speed feedback gain variable section, 19 …… Speed command value switching signal, 20 …… Speed gain switching signal, 22 …… Base, 23 …… First motor, 24 …… Post, 26 …… Second electric motor, 27 …… First arm, 28 …… Second arm, 29 …… Third arm
Arm, 30 …… 4th arm, 33 …… Motor power OFF switch.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Mikio Hasegawa 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Kenji Sogawa, 1006 Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd. (72) Inventor Akiyoshi Nakata, 1006 Kadoma, Kadoma City, Osaka Prefecture, Matsushita Electric Industrial Co., Ltd. (56) References JP 59-189416 (JP, A) JP 59-201109 (JP, A)

Claims (1)

[Claims] 1. An arm, a motor for driving the arm, a position sensor for detecting a current position of the motor, a current position of the motor as a feedback signal, and a deviation between the current position of the motor and a position command signal. The position deviation amplifier that amplifies and outputs the position deviation, and the command value output from the position deviation amplifier and a predetermined fixed command value are configured to be switchable, and in the case of direct teaching, the predetermined fixed value. A position deviation output switching unit that outputs a command value, which is a command value output from the position deviation amplifier during a reproducing operation, as a speed command value; a speed sensor that detects current speed information of the motor; A speed feedback gain variable section for amplifying and outputting the magnitude of speed information detected by a sensor; and the speed feedback gain variable section A signal output from the speed feedback signal, a speed deviation amplifier that amplifies the speed deviation that is a deviation between the speed feedback signal and the speed command value and outputs the current command value, and inputs the current command value, A direct teaching robot comprising a current control unit for controlling a current for driving the motor.