JPH0573148A - Work position adjusting method for robot and work feeder - Google Patents

Abstract

PURPOSE:To detect and set the optimum work positions of a robot and a work feeder. CONSTITUTION:A photodetector is mounted on a hand 12, and a photodetector is mounted on a work loading part 8 of a rotary work feeder 1. Either a polymerized point P1 or P2 between a rotational move locus R2 of the work loading part 8 and a rotational move locus R1 of the hand 12 is selected as the work position, an arm 11 is moved near the selected polymerized point P1 or P2, afterwards, the arm 11 is repeatedly oscillated forward and backward at a prescribed oscillating angle thetax according to a control program and during this oscillation, the work feeder 1 is manually rotated at fine speed. When the work loading part 8 and the hand 12 are polymerized at the selected position P1 or P2, photodetecting signals are outputted from the photodetectors, a CPU sets and stores the current position of the hand 12 in a non-volatile memory as the work position on the robot side. An operator immediately stops manually rotating the work fedder 1 and sets the position at that time as the rotation stop position of the rotary work feeder 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a work position adjusting method for a robot and a work feeder.

[0002]

2. Description of the Related Art A rotary work feeder provided with a plurality of work placement parts along the outer periphery of a rotary table, and a work is laid at a predetermined work position in cooperation with the operation of the rotary work feeder. Various types of robot hands are already known.

[0003] In order to properly grasp and handle the work carried on the rotary work feeder by the robot hand, the work position and the work position on the robot hand side are made to coincide exactly. It is necessary to change this because the movement position of the work placed on the rotary work feeder is restricted to the locus of circular motion determined by the radius from the rotation center of the rotary work feeder to the work placement part. Generally, in the case of a multi-indirect type robot hand, the robot hand is moved to the position of the work placement part when the rotary table is stopped at an arbitrary position, and the table rotation position at this time is set to the rotary type. While the work position of the work feeder is set, the coordinate position of the robot hand at this time is taught to the robot as the work position.

[0004]

However, when the degree of freedom of the robot hand is insufficient, for example, in a robot hand in which the hand at the tip of the arm is only swung in a horizontal plane, the work rest is stopped. The robot hand cannot be positioned according to the position, and both the movement position of the robot hand and the movement position of the work are restricted by the circular motion, so the robot hand can grip the work only at the overlapping position of both trajectories. Become. Therefore, in order for the robot hand to be able to grip the work, the stop position of the rotary table is set so that the work placement part matches the overlap position, while the overlap position is set as the work position for the robot. It needs to be set, but it is difficult to detect this visually.

Conventionally, in such a case, a position where the locus of movement of the robot hand and the locus of movement of the work are considered to overlap is roughly assumed, and the rotary table of the rotary work feeder and the arm of the robot are slightly near the position. Each time, the robot hand repeatedly tries and makes an error in the gripping operation to interpolate the rotational positions of the two to find the position where the work placement part and the hand overlap, but this is an operation to detect the overlapping position. However, there is a drawback that it is troublesome and tends to be inaccurate.

Therefore, an object of the present invention is to provide a work position adjusting method capable of easily and surely detecting and setting optimum work positions in both a robot and a work feeder.

[0007]

According to a work position adjusting method of the present invention, either a light receiving element or a light emitting element is mounted on a hand of a robot, and the hand is mounted on a work mounting portion of the rotary work feeder. A light emitting element or a light receiving element that is paired with the element mounted on the rotary work feeder is rotated at a minute speed, while the robot hand is moved by intersecting the moving direction of the work placement part of the rotary work feeder. The above object is achieved by repeatedly moving and detecting the presence or absence of a light receiving signal from the light receiving element, and setting the position of the hand and the rotational position of the rotary work feeder as the working position at the time when the light receiving signal is detected.

A rotary work feeder configured to intermittently rotate a rotary table whose rotation stop position is defined by a constant step width, that is, a rotary work in which it is difficult to arbitrarily set the rotary position of the rotary table. In the feeder, a work mounting plate that is rotatable and fixable to the rotary table is provided, and a light emitting element or a light receiving element paired with the element mounted on the hand is mounted on the work mounting portion of the work mounting plate. While the rotary table of the rotary work feeder is fixed at an arbitrary rotation stop position, only the work placement plate is rotated in small increments, while the robot is moved by intersecting the movement direction of the work placement part on the work placement plate. The hand is repeatedly moved, and the workpiece mounting plate is placed at the rotational position when the light receiving signal from the light receiving element is detected. By fixing the rotary table of the rotary work feeder, setting the substantial working position to a rotary work feeder.

[0009]

The robot hand is equipped with either the light-receiving element or the light-emitting element, while the work mounting portion of the rotary work feeder is equipped with the light-emitting element or the light-receiving element paired with the element mounted on the hand. , The rotary work feeder is rotated at a very small speed, and the robot's hand is repeatedly moved while intersecting the movement direction of the work placement part in the rotary work feeder.

When the rotation position of the work placement part and the position of the robot hand in the rotary work feeder match,
The light receiving element that detects the light from the light emitting element outputs a light receiving signal, and it is confirmed that the work placement part and the robot hand match each other. By setting the position of the hand and the rotational position of the rotary work feeder at the time when the light reception signal is detected as the respective work positions, the work positions of both the robot and the work feeder are determined.

[0011]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view showing an example of a general arrangement relationship between a rotary work feeder 1 and a loader robot 2. The rotary work feeder 1 is generally composed of a rotary table 3, a work placement plate 4, and a table drive mechanism 5. The table driving mechanism 5 is a servomotor or an actuator using a pneumatic pressure as a driving source, and the rotary table 3 is rotated around the table rotation axis θ by a constant step size θ.
The rotary table 3 is configured to rotate intermittently at r.
The rotation stop position is regulated by the table drive mechanism 5 with a constant step width θr. Further, when the plate mounting screw 6 is loosened in a state where the rotary table 3 is at any rotation stop position, the work mounting plate 4 can be arbitrarily rotated independently of the rotary table 3 by a manual operation. When the plate fixing screw 6 is tightened, the plate fixing screw 6 is integrally fixed to the rotary table 3. As shown in FIG. 2, on the outer peripheral portion of the work placing plate 4, a work placing portion 8 regulated by a set of three work guides 7 has a constant size corresponding to the step width θr of the rotary table 3. The works 9 placed at intervals and placed on the work placement part 8 are positioned by the work guide 7.

The loader robot 2 has a rotation axis J1 that swings the robot body 10 in a vertical plane, a sliding axis J2 that moves the arm 11 toward and away from the robot body 10, and a sliding axis J2. It has a rotation axis J3 that rotates the arm 11, a rotation axis J4 that rotates the hand 12 provided at the tip of the arm 11 around the arm 11, and a rotation axis CR that rotates the hand 12 along its central axis. ..

FIG. 3 is a block diagram showing a main part of the control device 13 for controlling the loader robot 2. The control device 13
Has a CPU 14, and in the CPU 14, a ROM 15 storing a control program and the like, a RAM 16 used for temporary storage of data, a non-volatile memory 17 storing teaching data and the like, a teaching operation panel for teaching an operation to a robot 1
8. An axis controller 21, an input / output interface 22, etc. for driving and controlling each axis of the robot main body 10 via an operation panel 19, a servo circuit 20 and a bus 23 are connected,
The teaching operation panel 18 or the operation panel 19 is provided with a lamp display body which is turned on based on a work position detection signal from the CPU 14.

Of the axes of the loader robot 2, the rotary axis J1 which changes the posture of the robot body 10 and the sliding axis J2 which is used for the final approach of the hand 12 can be used for moving the hand 12. The axes are shown in FIGS. 1 and 4.
There is only the rotation axis J3 as shown in FIG. Since the movement locus of the hand 12 is completely restricted by the locus R1 of the rotational movement having the span of the arm 11 as a radius, the position of the work placing portion 8 at the rotation stop position of the rotary work feeder 1 is set for the hand 12. It is usually impossible to move the work mounting portion 8 in the rotary work feeder 1 to a position where the work placing portion 8 can take the locus R2 of the rotary movement having a radius from the table rotation axis θ to the work guide 7.
Since it is completely regulated by, the position of the work placing part 8 cannot be changed conveniently according to the position of the hand 12. Therefore, in such a configuration, the hand 12 can hold the work 9 only when the hand 12 and the work placement portion 8 are simultaneously positioned at the overlapping positions of the rotational movement trajectories R1 and R2, respectively. The position of the work placement part 8 at the rotation stop position of the rotary table 3 is the overlapping position P1 or P2 of the rotational movement loci R1 and R2.
Adjust the relative mounting angle of the work mounting plate 4 with respect to the rotary table 3 so that the hand 1
It becomes necessary to set the rotation angle of the rotation axis J3 when 2 coincides with the overlapping position P1 or P2 of the rotational movement trajectory as the work position of the loader robot 2.

FIG. 5 is a schematic view showing an example of means for mounting a pair of light emitting element and light receiving element on the work placing portion 8 of the rotary work feeder 1 and the hand 12 of the loader robot 2. In the figure, each of 9a and 9b is a columnar block inscribed in each of the three work guides 7 arranged on the work mounting portion 8, and the light emitting element 24 is provided on one end surface of the block 9a. A light-receiving element 25 paired with the light-emitting element 24 is embedded in the center of one end face of the other block 9b while the optical axis is aligned with the central axis. A power supply 26 is connected to the light emitting element 24, while an output line from the light receiving element 25 is connected to the input / output interface 22 of the control device 13 via an amplifier 27,
The light receiving signal from the light receiving element 25 is detected by the CPU 14. The light receiving element 25 may generate an electromotive force by itself, or may change the resistance value or the like according to the light receiving state, but the final output from the amplifier 27 is an ON / OFF digital signal.

Hereinafter, with reference to the above-mentioned configuration, the relative mounting angle of the work placing plate 4 with respect to the rotary table 3, that is, the method of setting the working position in the rotary work feeder 1 and the hand 12 of the loader robot 2 are described. A method of setting the work position will be described.

When setting the work position, the operator first fixes the rotary table 3 of the rotary work feeder 1 at an arbitrary rotation stop position defined by the step width θr, loosens the plate fixing screw 6, and places the work on the work. The plate 4 is rotatable. Next, one of the blocks 9a and 9b is placed on the work placing portion 8 of the work placing plate 4 with the element embedding surface facing upward, while the loader robot 2 is operated via the teaching operation panel 18. , The hand 12 is gripped with the element embedding surface of the other block 9b or 9a facing downward, and either the overlapping point P1 or P2 of the rotational movement locus R2 of the work placing portion 8 and the rotational movement locus R1 of the hand 12 After selecting one as the work position, the teaching operation panel 18 is operated to drive the rotation axis J3, the hand 12 is visually moved to the vicinity of the selected overlapping point P1 or P2, and the operation is performed via the teaching operation panel 18. A work position detection command is input to the device 13, and the CPU 14 starts the work position detection process as shown in FIG.

The CPU 14, which has started the work position detection process, transmits the rotation axis J3 via the axis controller 21 and the servo circuit 20.
Pulse distribution to the servo motor of the arm 11 is started, and the arm 11 is rotated at a predetermined swing angle θ around the current position of the arm 11.
Swing forward and backward at x (setting value) (step S
1), it is determined in a predetermined detection cycle whether or not the light receiving signal from the light receiving element 25 is input at each position in the swinging process (step S2). If the light receiving signal is not input, the process starts in step S1. The swing motion of the arm 11 is repeatedly executed. Therefore, the hand 12 provided at the tip of the arm 11
Is a movement locus R1 while crossing the rotation movement locus R2 of the work placing portion 8 in the vicinity of the selected overlapping point P1 or P2.
Will be moved in and out of the rotational movement locus R2.

In the meantime, the operator manually rotates the work placing plate 4 to move the work placing portion 8 on which the block 9b or 9a is placed to the selected overlapping point P1 or P2.
To the vicinity of the position of the hand 12 and further rotating the work placing plate 4 little by little to move the work placing portion 8 on which the block 9b or 9a is placed at a speed sufficiently slower than the swing of the arm 11. Gradually approaches the rotational movement locus R1 of.

Then, the work placing portion 8 which moves little by little along the rotational movement locus R2 reaches the position of the selected overlapping point P1 or P2, and the hand 12 swings across the rotational movement locus R2. When approaching the position, the light emitted from the light emitting element 24 of the block 9a is detected by the light receiving element 25 of the block 9b, and both the work placement part 8 and the hand 12 are rotated and moved along the locus R2 and R.
It is confirmed that it is located at the overlapping point of 1, that is, the working position. Light receiving element 25 that detects light from the light emitting element 24
Inputs a light reception signal to the CPU 14 via the amplifier 27 and the input / output interface 22, and the CPU 14 that has detected the light reception signal in the determination processing of step S2 determines the current coordinate value of the hand 12, that is, the current servo motor of the rotation axis J3. Read the position and use the non-volatile RA as the working position of the hand 12.
At the same time as setting to M17, the pulse distribution is stopped to stop the swinging motion of the arm 11, and further, the work position detection signal is output to the teaching operation panel 18 or the operation panel 19 to turn on the lamp display for a predetermined time. The operator is informed that the placing portion 8 is at the work position (step S3), and the work position detection process is ended.

Further, the operator who confirms that the lamp indicator has turned on immediately stops the manual rotation of the work placing plate 4 and tightens the plate fixing screw 6 in this state to place the work placing plate 4 on the rotary table 3. After fixing, the blocks 9a and 9b are removed and the work is completed. At this time, since the rotary table 3 is fixed at the rotation stop position, every time the rotary table 3 is intermittently rotated by the step width θr by the table drive mechanism 5, the work mounting plate 4 also has a predetermined step width. It rotates intermittently at θr, and the work placing portions 8 arranged on the work placing plate 4 at intervals of θr are transferred one after another, and the selected overlapping point P1 or P
2, the loader robot 2 cooperates with the intermittent operation of the rotary work feeder 1 to carry out the work of arranging the work 9 at the position of the selected overlapping point P1 or P2. Become.

In this embodiment, when the CPU 14 detects the light receiving signal from the light receiving element 25, the lamp display is turned on for a predetermined time to notify the operator that the work placing portion 8 is at the working position. However, after detecting the light receiving signal from the light receiving element 25 and stopping the pulse distribution, the presence or absence of the light receiving signal from the light receiving element 25 is sequentially detected until the forced termination signal is input from the teaching operation panel 18. However, the lamp display may be turned on / off depending on the presence / absence of the light reception signal. In this case, the lamp indicator is immediately extinguished when the position of the work placing portion 8 is overloaded due to a delay in the operation of the operator manually operating the work placing plate 4 or the like.
It is possible to easily detect that an abnormality has occurred in the position of. Even if the position of the work placing portion 8 is overshooted due to operator delay or the like, the hand 1
Since 2 itself has already been positioned and stopped at the correct work position, the operator manually rotates the work placement plate 4 again to turn on the lamp indicator, thereby bringing the work placement part 8 to the proper work position. The workpiece mounting plate 4 can be positioned and fixed to the rotary table 3.
Since the swinging motion of the hand 12 is stopped, the positioning operation is easy.

When a servomotor is used as the drive source of the table drive mechanism 5 of the rotary work feeder 1, a non-axis controller for driving and controlling the servomotor is provided in the control device 13 to swing the arm 11. And the rotary table 3 are started to rotate at a very low speed (step S1), and at the stage when the light receiving signal from the light receiving element 25 is detected (step S2), the current position of the servo motor of the rotary axis J3 and the table drive mechanism 5 are detected. The current position of the servo motor of the non-volatile RAM 1 is read as the working position of the hand 12 and the working position of the rotary work feeder 1, respectively.
7, the pulse distribution is stopped to stop the swinging motion of the arm 11 and the rotation of the rotary table 3 (step S3), whereby all the manual operations in the above embodiment can be automated. Since the drive of the rotary table 3 by the servomotor can be performed with a minute step size, it is not necessary to provide the work mounting plate 4 separately from the rotary table 3 as in the above-described embodiment. In this case, in the cooperative operation of the rotary work feeder 1 and the loader robot 2, the work position of the worktable of the rotary table 3 set in the nonvolatile RAM 17 is set as the original position.
By the pulse distribution from the CPU 14 according to the step width θr, the work mounting plate 4 integrated with the rotary table 3 is intermittently driven by the step width θr.

The method of mounting the light emitting element 24 and the light receiving element 25 in each of the above-described embodiments is carried out through the blocks 9a and 9b having the same shape as the work in consideration of retrofitting to the commercially available robot or the work placing part 8. However, it is also possible to directly attach each of the light emitting element 24 and the light receiving element 25 to a robot hand, a work mounting plate, or the like.

[0026]

According to the work position adjusting method of the present invention, the light emitting element and the light receiving element are mounted on both the robot hand and the work placing portion of the rotary work feeder, and the work placing portion of the rotary work feeder is moved. The position of the hand at the time when the light receiving signal is detected by detecting the presence or absence of the light receiving signal from the light receiving element by rotating the rotary work feeder at a minute speed while repeatedly moving the robot's hand crossing the direction. Since the rotation position of the rotary work feeder and the rotary work feeder are set as the work position, the trial and error of the actual gripping operation is repeated and the work feeder and the hand are repeatedly moved while shifting the positions of the rotary work feeder and the robot as in the conventional case. The troublesome operation such as detecting the work position common to both is eliminated, and the optimum work position can be easily and surely detected. It can be set up.

[Brief description of drawings]

FIG. 1 is a perspective view showing a positional relationship between a rotary work feeder and a loader robot according to an embodiment to which the method of the present invention is applied.

FIG. 2 is a plan view showing a rotary work feeder according to the embodiment.

FIG. 3 is a block diagram showing a main part of a control device for a loader robot of the same embodiment.

FIG. 4 is a conceptual diagram showing a movement path of a work placing part of the rotary work feeder and a hand of a loader robot in the same embodiment.

FIG. 5 is a view showing a mounting means of the light emitting element and the light receiving element adopted in the embodiment.

FIG. 6 is a flowchart showing an outline of work position detection processing by the control device of the loader robot of the embodiment.

[Explanation of symbols]

 1 Rotary Work Feeder 2 Loader Robot 3 Rotary Table 4 Work Place Plate 8 Work Place 9a Light Emitting Element Embedded Block 9b Light Emitting Element Embedded 12 Hand 13 Controller 14 CPU 15 ROM 17 Nonvolatile Memory 22 Interface 24 Light emitting element 25 Light receiving element 27 Amplifier J3 Rotating axis that swings the hand R1 Hand movement locus R2 Work placement locus

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location B65G 47/88 D 8010-3F 47/90 B 8010-3F

Claims (2)

[Claims] 1. A method of adjusting a hand work position of a robot and a work position of a rotary work feeder, wherein either a light receiving element or a light emitting element is attached to a hand of the robot, and a work is placed on the rotary work feeder. A light emitting element or a light receiving element paired with the element attached to the hand is attached to the part, and the rotary work feeder is rotated at a minute speed, while intersecting with the moving direction of the work placement part in the rotary work feeder. The robot hand is repeatedly moved to detect the presence or absence of a light receiving signal from the light receiving element, and the position of the hand at the time when the light receiving signal is detected and the rotational position of the rotary work feeder are set as working positions. How to adjust the position of the robot and work feeder. 2. In a method for adjusting a hand work position of a robot and a work position of a rotary work feeder, a rotary table having a rotation stop position defined by a constant step width and a rotatably and fixedly mounted on the table. A rotary work feeder is configured by a work placing plate on which a work is placed with the constant step width, and either the light receiving element or the light emitting element is attached to the hand of the robot, and the work placing plate of the work placing plate is attached. A light emitting element or a light receiving element that is paired with the element mounted on the hand is mounted on the work mounting part, and only the work mounting plate is mounted in a state where the rotary table of the rotary work feeder is fixed at an arbitrary rotation stop position. While rotating the robot in small increments, the robot hand is repeated by intersecting the movement direction of the work rest on the work rest plate. It is moved to detect the presence or absence of a light receiving signal from the light receiving element, and the work placing plate is fixed to the rotary table of the rotary work feeder at the rotation position at the time when the light receiving signal is detected, and the light receiving signal is detected. A method for adjusting the position of a robot and a work feeder, which is characterized by setting the position of the hand at a point of time as a work position.