JPH09239682A - Work feeding method and device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the inexpensive work feeding device which can cope in shape with the various kinds of works. SOLUTION: A robot 3 sucks up each work within a pallet 2 by means of a magnet type depalletizing hand 12 so as to alternately feed each work onto tables 17 and 18 while each work is being left as is in a random posture. The integral and reciprocal movements of the tables 17 and 18 allow a camera 19 to photograph alternately each work over the tables 17 and 18. The posture of each work is recognized by an image processing device 20 based on visual information arrested by the camera 19, and its posture recognition information is thereby transferred to the robot 3. A transshipping hand 10 alternately holds each work over the tables 17 and 18 while its posture is being corrected so as to be aligned the posture of each work 17 and 18, and after each work has been aligned with a definite posture, each work is thereby fed to a conveyor 30.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a work supply method and a work supply apparatus called auto depalletizing or auto depalletizer, and more specifically,
The present invention relates to a method and an apparatus in which a large number of works are picked up one by one from a pallet that is housed in a random posture in a so-called bulk state, aligned in a predetermined posture, and then supplied to a transfer stage.

[0002]

2. Description of the Related Art As a work supply device of this type, for example, a pallet in which a large number of rod-shaped works are randomly accommodated is used.
After the image is picked up by a visual sensor such as a CD camera, and the posture of the work determined to be in the uppermost stage (that is, the work determined to be free from other work on the upper side) is recognized by the three-dimensional image processing apparatus, There is one in which a finger gripping type hand provided to a handling robot is used to supply the workpiece to a predetermined work supply position.

As another type of work supply apparatus, an electromagnet provided in a Cartesian coordinate type loader is lowered to a predetermined position on a pallet in which a large number of works are randomly stored, and the electromagnet is moved. There is one in which the work is thrown into the aligning device only when the work is sucked and supported, and the work is aligned in a fixed posture by a mechanical aligning method such as a seesaw type in the aligning device.

[0004]

In the former one of the conventional work supply devices, it is necessary to identify any one of a large number of works picked up by the visual sensor. The image processing procedure for recognizing the posture becomes complicated, the image processing device becomes expensive, and the target work is not versatile. For example, a work having a relatively simple shape such as a rod-like work is recognized. Even if it can be done, it cannot deal with a work having a complicated shape, and even if it can be recognized, erroneous recognition increases.

Regarding the latter work supply device,
Although it is advantageous in terms of price because the image processing apparatus such as the former is not required, it is not preferable because another conveying means is required when the aligned work is supplied to the conveyor of the processing line. In addition, as mentioned above,
Since the postures of the workpieces are aligned by a mechanical method, the workpieces that can be aligned are significantly restricted, which leaves a problem in terms of versatility.

The present invention has been made in view of the above problems, and it is an object of the present invention to provide a work supply method and a work supply apparatus which are low in price and have high versatility for a work.

[0007]

According to a first aspect of the present invention, a plurality of works are picked up one by one from a pallet in which a plurality of works are stored in a random posture, aligned in a predetermined posture, and then mounted on a transfer stage. A method of supplying, for a handling robot equipped with a finger gripping type transfer hand and a suction type depalletizing hand that can be selectively switched, the selected depalletizing hand is placed at a random position in a pallet. A step of moving and picking up and supporting any one of the works, and then placing the work in the work area of the work posture recognition stage; While recognizing the posture and switching the hand of the handling robot from the depalletizing hand to the transfer hand, Receiving the posture recognition information of the work after the image processing, changing the posture of the transfer hand so that the work on the work area can be grasped, and then grasping the work on the work area with the recognition hand; The step of transferring the work to the transfer stage after correcting the attitude of the transfer hand so that the attitude of the work gripped by the transfer hand becomes the alignment attitude required on the transfer stage side. It has a feature.

According to a second aspect of the present invention, when the depalletizing hand according to the first aspect of the invention cannot adsorb and support the work in the pallet, the handling robot positions the depalletizing hand in the pallet. The feature is that the work is changed and the suction support operation of the work is executed again.

According to a third aspect of the present invention, the work posture recognizing stage according to the first or second aspect of the present invention has two work areas arranged side by side.
The visual sensor alternately images the work on the two work areas, while the handling robot alternately supplies the work to the two work areas and alternately picks up and moves the work from the two work areas. The feature is that it is transferred to the mounting stage.

According to a fourth aspect of the present invention, there is provided a device for picking up one work at a time from a pallet in which a large number of works are stored in a random posture, aligning the works in a predetermined posture, and supplying the works to a transfer stage. In addition to having a finger gripping type transfer hand and a suction type depalletizing hand that can be selectively switched, the selected depalletizing hand is moved to a random position in the pallet to pick up one of the workpieces. While supporting and placing the work on the table of the work posture recognition stage, switch the hand from the depalletizing hand to the transfer hand and then grasp the work after posture recognition processing on the work posture recognition stage. A handling robot that moves the transfer stage onto the transfer stage while changing the position to a required alignment position on the transfer stage side; Provided above the table of the work posture recognition stage, the visual sensor for imaging the work placed on the table, and recognizes the posture of the work based on the work visual information from the visual sensor, The handling robot is characterized by being provided with an image processing device for giving the posture recognition information of the work to the control system of the handling robot prior to gripping the work on the work posture recognition stage by the transfer hand.

According to a fifth aspect of the present invention, in addition to the position fixed single visual sensor, the work posture recognition stage according to the fourth aspect of the invention is integrally reciprocated to reciprocate. It is characterized in that two tables which are alternately positioned in the imaging area of the visual sensor at a limited position are provided.

The invention according to claim 6 is characterized in that the transfer stage in the invention according to claim 4 or 5 is a transfer start end portion of a work transfer conveyor.

[0013]

According to the first aspect of the present invention, the depalletizing hand of the handling robot temporarily puts one workpiece, which is suction-supported from the pallet, in the workpiece area of the workpiece posture recognition stage in a random posture. On the other hand, after recognizing the posture of the work by image processing, the posture recognition information of the work is fed back to the control system of the handling robot to correct the posture of the transfer hand, and the work grasped by the transfer hand is transferred. It is adapted to be transferred to the transfer stage while being corrected to a predetermined alignment posture required on the stage side. Therefore, since it is sufficient for image processing to recognize the posture of a single workpiece on the workpiece posture recognition stage, the image processing procedure for workpiece recognition can be simplified and equipment costs can be reduced. As described above, since a single work is always imaged and recognized, it is possible to easily recognize the posture of a work with a complicated shape. Especially, by changing the posture recognition algorithm or the depalletizing hand fingers. It becomes possible to deal with works of various shapes, and the versatility is significantly increased.

Further, since the work after the posture recognition is transferred after the posture is corrected to the posture required by the transfer stage which is the destination of the work supply, a transfer means other than the handling robot is used. Is not required, and this can also reduce the equipment cost.

According to the second aspect of the present invention, when the depalletizing hand fails to pick up the work in the pallet, the position for picking up the work is changed, and the operation for picking up the work is repeatedly executed. Therefore, in addition to the effect similar to that of the invention described in claim 1, there is an effect that the probability of adsorbing a work is increased and a trouble such as insufficient supply of the work in a subsequent process can be prevented.

According to the third aspect of the present invention, the visual sensor alternately images the work on the two work areas of the work posture recognition stage, while the handling robot alternately picks up the work on the two work areas. Since the work is supplied and the work is alternately taken out from the two work areas and transferred to the transfer stage, in addition to the same effect as the invention according to claim 1 or 2, the waiting time of the handling robot is reduced. Then, the capacity can be utilized to the maximum, and as a result, the work supply efficiency from the pallet to the transfer stage is significantly improved.

According to the invention described in claim 4, according to claim 1,
As a means for realizing the processing of the invention described in (1), a table as a work area and an image processing device are provided in addition to the handling robot and the visual sensor. The effect is obtained.

According to the invention of claim 5, claim 3
In the invention described in (2), the two work areas are integrally reciprocated, and the two tables are simultaneously reciprocally moved so as to be alternately positioned in the imaging area of a single visual sensor. Therefore, the same effect as the invention according to claim 3 is obtained.

According to the invention of claim 6, claim 4
Alternatively, since the transfer stage in the invention described in 5 is used as a transfer start end portion of the work transfer conveyor, the work robot directly inputs the aligned work to the work transfer conveyor from the work position recognition stage by the handling robot. Further, in addition to the same effects as the invention described in the fifth aspect, there is an advantage that no other transfer means other than the handling robot is required for supplying the work from the pallet to the work transfer conveyor.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a diagram showing a typical embodiment of the present invention, in which a large number of works (not shown) are taken out one by one from a pallet 2 which is randomly stored. It shows a device for supplying to a line conveyor (work transfer conveyor) 30 of a processing line.

As shown in FIG. 1, the pallet positioning table 1
In this, a rectangular pallet 2 in which a large number of works are randomly stored, that is, randomly arranged, is carried in by a not-shown forklift or the like and positioned at a predetermined position.

A pallet 2 is placed on the pallet positioning table 1.
A Cartesian coordinate type three-axis type handling robot (hereinafter, simply referred to as a robot) 3 that functions as a pickup loader for picking up the workpieces inside one by one is provided. This robot 3 has a column 4 and this column 4
The side beam 5 slidable in the X direction, the carrier 6 slidable in the Y direction with respect to the side beam 5, and the rod arm 7 vertically movable (Z direction) with respect to the carrier 6. The hand unit 8 is attached to the lower end of the rod arm 7.

The hand unit 8 is, as shown in FIG.
A finger gripping type transfer hand 10 having a plurality of fingers (jaws) 9 for directly gripping a work and a suction type depalletizing hand 12 having an electromagnet 11 as a main element are provided with a common direction by making the directions different from each other by 90 degrees. The support 13 is supported by the body 13. The support 13 is supported by the bracket 14 via a shaft 15 so as to be rotatable in the γ direction.

The hand unit 8 has a degree of freedom in rotation in the α direction in which the entire hand unit 8 rotates with respect to the rod arm 7 about the axis of the rod arm 7, and both hands 10 and 12 have the same degree of freedom. In addition to the rotational degrees of freedom in the γ direction that rotates about the shaft 15 and the rotational degrees of freedom in the β direction in which the transfer hand 10 rotates about its axis, the rotational degrees of freedom not shown in the drawing correspond to the respective rotational degrees of freedom. It has a motor and a speed reducer, and both hands 10 and 12 in the γ direction
It is possible to index either one of the hands 10 or 12 on the same axis as the rod arm 7 by rotating the hands 10 or 12 forward or backward by 0 °, and selectively use both of the hands 10 or 12. ing.

As will be described later, the depalletizing hand 12 is used when the work is conveyed from the pallet 2 to the table 17 or 18, while the transfer hand 10 transfers the work from the table 17 or 18 to the line conveyor 30. Used when transporting.

A pedestal 16 serving as a work posture recognition stage is installed on the pallet positioning table 1, and a pair of tables 17 and 18 functioning as a work area on which a work is placed are arranged side by side on the pedestal 16. Has been done. The pair of tables 17 and 18 are driven by a slide driving means (not shown) to integrally move the tables and linearly reciprocate in the Y direction by a predetermined stroke.

A CCD sensor (hereinafter, simply referred to as a camera) 19 is provided as a visual sensor above the pedestal 16.
Is fixed downward, and the CCD camera 19 captures an image of the work placed on the table 17 or 18 as described later. That is, when the pair of slide tables 17 and 18 reciprocate integrally, the slide tables 17 and 18 are alternately positioned with respect to the imageable area of the camera 19.

Then, the visual information of the work captured by the camera 19 is taken into the image processing device 20, and the image processing device 20 recognizes the posture of the work to be imaged by the feature extraction method, The posture recognition information is input to the controller 21 of the robot 3.

Reference numeral 2 in FIG. 1 is the image processing apparatus 20.
Or a control panel including the controller 21 of the robot 3,
Reference numeral 23 is an operation panel.

Next, a series of movements of the work supply apparatus configured as described above will be described with reference to the flow charts shown in FIGS.

As shown in FIGS. 3 to 5, the so-called work supply device provides so-called on condition that the pallet 2 containing a large number of works in a random posture is positioned at a predetermined position on the pallet positioning base 1. The depalletizing work is started (steps S1 and S2 in FIG. 3).

First, the robot 3 performs a hand switching operation, and as shown in FIG. 2, the depalletizing hand 12 having the electromagnet 11 as a main element is indexed so as to be positioned on the same axis as the rod arm 7 ( In step S3), the operation of picking up the work in the pallet 2 is started. That is, the robot 3 drives each of the side beam 5, the carrier 6 and the rod arm 7 based on the teaching data stored in advance and moves the depalletizing hand 12 at the tip of the rod arm 7 to a random position in the pallet 2. One of the works in the pallet 2 is moved and supported by suction (step S4).

When the depalletizing hand 12 fails to pick up the work, the position in the pallet 2 where the depalletizing hand 12 should go to pick up the work is changed so as to be different from the previous position. The work pick-up operation is repeatedly executed again (steps S5 and S6).

When the depalletizing hand 12 sucks and supports one work, the robot 3 moves the depalletizing hand 12 onto one table 17 on the pedestal 16 and places the work on the table 17. This is released (step S7).

When one work is placed on the table 17, the pair of tables 17 and 18 on the pedestal 16 slide integrally (shift operation) in the direction of arrow Y ₁ in FIG. As a result, the table 17 on which the work is previously placed is positioned in the imageable area of the camera 19 (step S8).

Then, the camera 19 picks up an image of the work on the table 17, and the picked-up image is taken into the image processing apparatus 20, and the image processing apparatus 20 recognizes the posture of the work on the table 17. Image processing by a feature extraction method such as matching is executed (steps S9 and S10). The posture of the work is recognized as the position of the work in the X, Y, and θ directions with respect to the table 17, and the position data in the X, Y, and θ directions, which is the work posture recognition information, is transferred to the controller 21 of the robot 3 ( Steps S10 and S19).

In parallel with such image processing, the robot 3 again moves the depalletizing hand 12 to the pallet 2 side and uses the depalletizing hand 12 to pick up the work in the pallet 2 as in the previous case. The operation is executed again (steps S11 to S13).

When the robot 3 suction-supports one work with the depalletizing hand 12, the work is transferred onto the other table 18 on the pedestal 16 (step S14). At this time, since the image processing of the work placed on the other table 17 has already been completed, waiting for the work to be placed on the table 18 as described above, both tables 17, 18 are processed. Slide all in the direction of the arrow Y _{2 in} FIG. 1 to the state shown in FIG. 1 (step S15). As a result, the table 18 on which the work is placed is positioned in the image capturing area by the camera 19 later, and the image capturing by the camera 19 and the process for recognizing the posture of the work by the image processing device 20 are executed, The posture recognition information is transferred to the controller 21 of the robot 3 as in the previous case (step S1).
6, S17, S31).

On the other hand, the robot 3 which has finished transferring the work on the table 18 executes the hand switching operation, and the transfer hand 10 is placed on the same axis as the rod arm 7 in place of the depalletizing hand 12 until then. The position is determined (step S18).

When the hand switching work is completed in this way,
The robot 3 has a table 17 whose image processing has been completed first.
In order to grip the upper work by the transfer hand 10, the transfer hand 10 is moved above the table 17 and the gripping operation is executed.

That is, the posture of the work on the table 17 is already known by the controller 21 of the robot 3 based on the posture recognition information previously transferred from the image processing apparatus 20, so that the robot 3 can detect the side beam 5 and the carrier. 6 and rod arm 7 are moved and transfer hand 1
0 is moved in the β direction to correct the position and posture of the transfer hand 10 so that the workpiece on the table 17 can be gripped, and then the transfer hand 10 moves the table 17
The upper work is gripped (steps S19 and S20).

Then, the robot 3 transfers the work gripped by the transfer hand 10 to the starting end of the line conveyor 30, and the information on the alignment posture required by the line conveyor 30 at the time of transfer is previously set by the robot 3. Controller 21
The robot 3 has the transfer hand 10
When the work is gripped by, the transfer hand 10 is rotated in the α direction of FIG. 2 to correct the posture of the work, and then the work in the aligned posture is transferred to the line conveyor 30 (step S21).

After the transfer of the work to the line conveyor 30 is completed, the robot 3 switches the transfer hand 10 to the depalletizing hand 12 again, and then transfers the depalletizing hand to the pallet 2 side. 12 is moved to adsorb and support a work at a random position in the pallet 2 (steps S22 to S25). And the pedestal 16
The upper table 17 is in an empty state by previously aligning and supplying the work onto the line conveyor 30, so that the robot 3 holds the workpiece held by the depalletizing hand 12 in the empty state. It is transferred onto the memory 17 (step S26). At this time, the work whose orientation has been recognized by image processing is still placed on the other table 18 facing the camera 19.

Then, when a work is placed on the table 17, both the tables 17 and 18 slide simultaneously in the direction of the arrow Y ₁ in FIG. 1, and the work on the table 17 is imaged by the camera 19. Image processing by the image processing device 20 for posture recognition is executed (step S2).
7-S29, S19).

On the other hand, the robot 3 which has finished transferring the work to the table 17 switches the hand from the depalletizing hand 12 to the transfer hand 10 again, and then the posture recognition information in steps S16 and S17. Based on the above, the work on the other table 18 is grasped and aligned, and then transferred to the line conveyor 30 (step S30).
(S33) After the transfer of the work to the line conveyor 30, the robot 3 switches the transfer hand 10 to the depalletizing hand 12, and then suction-supports the work at a random position in the pallet 2. Then, this work is placed on the table 18 which has been previously placed in the empty state (steps S34 to S38).

When a work is placed on the table 18, both the tables 17 and 18 are simultaneously moved to the arrow Y in FIG.
_{While the} slide operation is performed in _two directions, the imaging of the work on the table 18 by the camera 19 and the image processing by the image processing device 20 are executed (steps S39 to S41,
(S31), the robot 3 again switches the hand from the depalletizing hand 12 to the transfer hand 10 (step S18), and thereafter, the series of operations of steps S19 to S41 is repeated.

As described above, in the work supply apparatus of the present embodiment, the robot 3 picks up a random work in the pallet 2 one by one, and the pair of tables 17 and 1 is used.
8 is alternately supplied, the camera 19 alternately picks up images of the works on the pair of tables 17 and 18 so that the image processing device 20 recognizes the postures of the works, and the robot 3 further moves the hand. While selectively switching between, while sequentially grasping the workpieces on the respective tables 17 and 18 based on the fed-back workpiece posture recognition information while aligning the workpieces in a predetermined posture and sequentially supplying the workpieces to the line conveyor 30, Random works in the pallet 2 are continuously supplied to the line conveyor 30 after being aligned in a fixed posture.

Further, even when the target work is changed, it can be easily dealt with by simply exchanging the finger 9 of the transfer hand 10 and the posture recognition algorithm (software) in the image processing apparatus 20. . Depending on the type of work, an electromagnet type depalletizing hand 12
Instead of this, it is also possible to use a vacuum cup type hand.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a configuration of an entire work supply device showing a typical embodiment of the present invention.

FIG. 2 is an enlarged explanatory view of the hand unit shown in FIG.

3 is a flowchart showing a processing procedure of the work supply device shown in FIG.

FIG. 4 is a flowchart showing a processing procedure of the work supply device shown in FIG.

5 is a flowchart showing a processing procedure of the work supply device shown in FIG.

[Explanation of symbols]

 2 ... Pallet 3 ... Handling robot 8 ... Hand unit 9 ... Finger 10 ... Transfer hand 11 ... Electromagnet 12 ... Depalletizing hand 16 ... Pedestal (work posture recognition stage) 17, 18 ... Table (work area) 19 ... CCD camera ( Visual sensor) 20 ... Image processing device 30 ... Line conveyor (transfer stage)

Claims (6)

[Claims] 1. A method in which a plurality of works are taken out one by one from a pallet that is housed in a random posture, aligned in a predetermined posture, and then supplied to a transfer stage, which can be selectively switched and used. For a handling robot equipped with a finger-holding type transfer hand and a suction type depalletizing hand, the selected depalletizing hand is moved to a random position in the pallet to support one of the workpieces by suction. The step of placing the work in the work area of the work posture recognition stage, the step of recognizing the posture of the work by image processing of the work on the work area with a visual sensor, and the hand of the handling robot. While switching from the palletizing hand to the transfer hand, the posture recognition information of the work after image processing is received. The step of changing the posture of the transfer hand so that the workpiece on the work area can be grasped and then grasping the workpiece on the work area by the transfer hand, and the posture of the workpiece grasped by the transfer hand is And a step of transferring the work to the transfer stage after correcting the attitude of the transfer hand so that the transfer stage has a required alignment attitude. 2. When the depalletizing hand cannot suck and support the work in the pallet, the handling robot changes the position of the depalletizing hand in the pallet and executes the suction and support operation of the work again. The work supply method according to claim 1, wherein 3. The work posture recognition stage has two work areas arranged side by side, and the visual sensor alternately picks up images of the works on the two work areas, while the handling robot operates on the two work areas. The work supply method according to claim 1 or 2, wherein the works are alternately supplied, and the works are alternately taken out from the two work areas and transferred to a transfer stage. 4. A device for picking up works one by one from a pallet in which a large number of works are stored in random postures, aligning them in a predetermined posture, and then supplying them to a transfer stage, which can be selectively switched and used. In addition to having a finger gripping type transfer hand and a suction type depalletizing hand, the selected depalletizing hand is moved to a random position in the pallet to suck and support one of the workpieces While the work is placed on the table of the work posture recognition stage, the hand is switched from the depalletizing hand to the transfer hand, and the work after the posture recognition processing on the work posture recognition stage is grasped and required on the transfer stage side. A handling robot that transfers the workpiece onto a transfer stage while changing the posture to an aligned posture that A visual sensor provided above the table for picking up an image of the work placed on the table, and the posture of the work is recognized based on the visual information of the work from the visual sensor, and the handling robot transfers the work. 2. A work supply device, comprising: an image processing device that gives the work robot's posture recognition information to the control system of the handling robot prior to gripping the work on the work posture recognition stage. 5. The work posture recognizing stage has, in addition to a single fixed-position visual sensor, reciprocally moved integrally and is alternately positioned in the imaging area of the visual sensor at the reciprocal movement limit position. The work supply device according to claim 4, wherein two tables are provided. 6. The work supply apparatus according to claim 4, wherein the transfer stage is a transfer start end portion of a work transfer conveyor.