JPH01246087A - robot equipment - 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 [Field of Industrial Application] The present invention relates to a robot device that includes a robot body and a robot hand that is detachably attached to the robot body.

[Conventional technology] Conventionally, when a single robot processes a wide variety of workpieces with different shapes, weights, materials, functions, etc., multiple robot hands that can be detachably attached to the robot body have been prepared. A robot hand with fingers that is driven in an optimal state for the work to be processed is selected, and after being attached to the robot body, gripping, suction, etc. are performed by driving the fingers provided on the robot hand. The work was transported, assembled, etc.

After separating the robot hand configured in this way from the robot body, when reattaching the same robot hand to the robot body and starting work, it is necessary to align the fingers' origin positions. The finger is once returned to its original position, and after detecting the original position of the fingers, the workpiece is grasped and suctioned.

[Problems to be Solved by the Invention] However, when a robot hand equipped with fingers driven in this manner is attached to a robot body, the return time required to return the fingers to the home position is approximately 10 per drive axis on average. In addition to being long (seconds), this return time is required each time the robot hand is attached, and the robot cannot start the next task until the return time has elapsed.

Therefore, an object of the present invention is to shorten the return time required to return to the origin position when attaching a removable robot hand to the robot body, thereby improving the processing capacity of the robot device. .

[Means for Solving the Problems] In order to solve the above-mentioned problems and achieve the objectives, the robot device of the present invention has the following configuration: a robot body, a robot body that is detachably attached to the robot body, A robot device comprising at least two robot hands each having at least two or more fingers movable for gripping a workpiece, the robot hand being attached to the robot body and gripping the workpiece. After the gripping operation is completed, the robot hand is removed from the robot body after the fingers are moved to a position near the gripping position of the next workpiece to be gripped by the robot hand.

Preferably, the robot hand includes a finger driven by a drive means, and a locking means for locking the drive means, and the robot body includes a storage means for storing a drive amount of the drive means, When the robot hand is detached from the robot body after the finger is driven, the locking means holds the driving means in a locked state.

Preferably, the storage means stores workpiece pulse information PN of the finger position corresponding to each of the workpieces, locking pulse information Qv corresponding to the locking position of the locking means, and the workpiece pulse information Y. , and pulse information RN consisting of the smaller absolute value obtained by subtracting the locking pulse information Q, QM+1 from the above.

Preferably, when the amount of rotation of the driving means of the finger is M and the number of pulses per rotation is A, C1l RN A-M is closest to the pulse information Rs.
The number of pulses Zr+ that minimizes the value of l, and the number of pulses Z
In order to detect s at an early stage, the storage device is provided with a table that determines the forward and reverse rotation directions of the drive means.

[Operation] After the robot hand is attached to the robot body and the gripping operation of the workpiece is completed, the robot hunt moves its fingers near the gripping position of the next workpiece to be gripped, and then the robot hunt is detached from the robot body. work like that.

Immediately before detaching the robot hand from the robot body, the drive amount of the finger driven by the drive means provided on the robot hand is stored in the storage means, and the finger drive means is locked by the locking means. It then works to attach the robot hand to the robot body again.

Alternatively, the finger is driven by reading the pulse information Rs from a table provided in the storage means, the finger drive means is held in a locked state by the locking means, and the robot hand is mounted on the robot body again. work.

Alternatively, the number of pulses z can be determined from the table provided in the storage means.
In order to read the number of pulses zN and detect the number of pulses zN at an early stage, the driving means is rotated in the forward or reverse rotational direction.

[Embodiments] Hereinafter, embodiments of the robot apparatus of the present invention will be described with reference to the drawings. FIG. 1 is an external perspective view showing an embodiment of the robot device of the present invention. In FIG. 1, the robot body 2 is constructed in a well-known manner. It is electrically connected to the main control section 3, and control signals and drive currents for various drive means to be described later are supplied from the main control section 3.

FIG. 2 is a block diagram of the control means 300 built in this main control section 3. In FIG.
The U device 301 is equipped with a central processing unit CPU, a storage section Mm, and an I10 device. On the other hand, a driver 3 provided to drive a servo motor 56 to be described later
03 is connected to a servo module 302, and the drive control of the servo motor 56 is performed by this servo module 302.
It is designed to execute based on control signals from.

For this purpose, an encoder 57, which will be described later, is provided on the rotating shaft of the servo motor 56, and a rotation angle signal detected by the encoder 57 is inputted to the servo module 302, thereby achieving so-called feedback drive of the motor drive. It is designed to compose a system.

Here, this servo module 302 is a central processing unit C
It is equipped with a PU, a storage section Ms, and an I10 device, and the above-mentioned CPU device 301 and servo module 302 are connected via a shared memory 304, and mutual control signals and position information are exchanged through this shared memory. Memory 304
I am trying to do it through .

Furthermore, a hardware-configured deviation counter 302a is connected within this servo module 302, and is used during the operation described below.

On the other hand, inside the shared memory 304, there is a command area for processing an instruction set commonly used by the CPU device 301 and the servo module 302, a current position area for writing the current position of a finger to be driven, which will be described later. A target value area is provided in which the value of the target position is written.

Again, in FIG. 1, a single support arm 6 is supported on the upper surface of a frame body 2A constituting the frame of the robot body 2, and a main carriage body 9 on which an X-axis motor 10 is mounted is connected to a parallel movement mechanism (not shown). is engaged with the X-axis motor 1.
When 0 is driven, it moves in parallel in both directions indicated by arrows X in the figure.

The sub-carriage body 1, which is configured to move parallel to the side surface of the single support arm 6, is engaged with a parallel movement mechanism (not shown) which receives driving force from a Y-axis motor 8.
When the Y-axis motor 8 is driven, it moves in parallel in both directions indicated by arrow Y in the figure.

This sub-carriage body 1 is integrally provided with a two-axis motor 7, and the shank body 4 driven by this two-axis motor 7 is moved by a parallel movement mechanism (not shown) in the vertical direction indicated by the arrow 2 in the figure. Being able to move through. That is, the shank body 4 is driven to any position in three orthogonal axes indicated by arrows X, Y, and Z in the figure.

By the way, a robot hand stocker 30 including a plurality of holding parts 30A for holding a plurality of robot hands 5 in fixed positions as shown in the figure is fixed to the side surface of the frame body 2A, and these plurality of holding parts 30A A plurality of robot hands 5 are prepared to be held in order to handle a wide variety of workpieces 20. In the figure, only two robot hands 5, which are the minimum necessary number, are shown to simplify the explanation.

The aforementioned shank body 4 is equipped with an engagement device (not shown) that operates a mounting mechanism (not shown) to attach or detach the robot hand 5 held in place in this manner as necessary. .

The table 11 has a surface portion 11A that is parallel to the plane defined by the above-mentioned X axis and Y axis, and this surface portion 11A
A pallet holder 14 and a holder 15 are fixed on the top, and the pallet holder 14 holds the pallet 13 fed from a pallet supply device (not shown) in a predetermined position, while the holder 15 holds the assembly 21 in a predetermined position. hold in
When the work on the assembly 21 is completed, the process moves to the next step (not shown).

Here, the works 20 are regularly arranged in holders (not shown) provided on the pallet 13, and the numerical control of the shank body 4 described above can also be performed by oven control.

Further, the near compressor 25 is installed below the table 11, and is connected to a vacuum pressure generator, an air cylinder, etc., which will be described later, via an air pipe (not shown).

The operation of the robot device configured as described above is executed according to an operation program inputted in advance to the main control section 3. - To give an example, when the type of workpiece 20 placed on the pallet 13 and supplied is determined, this workpiece 2
After the shank body 4 has been moved, the robot hand 5 equipped with the optimal fingers for handling the object is attached and moved to the work starting position on the workpiece 20 to start the work.

When the workpiece 20 is changed, the robot hand 5 that has been used until then is temporarily moved to the robot hand stocker 3.
After the robot hand 5 is returned to zero, the robot hand 5 most suitable for the changed workpiece is attached after the shank body 4 is moved, and the work is resumed.

FIG. 3 is a side view showing an example of the robot hand 5 used in the robot device shown in FIG. 1.

In FIG. 3, a base 52 serving as a base of the robot hand 5 has a substantially U-shape.
A servo motor 56 is attached to the upper surface of the base 52, and side plates 52A and 52B are hung from both edges of the base 52, respectively.

These side plates 52A, 52B support guide shafts 53A, 53B parallel to each other without rotational freedom, while
A left-hand threaded portion 54A and a right-hand threaded portion 54 are connected approximately at the center.
A screw shaft 54 integrally provided with B is rotatably supported via a bearing (not shown).

The guide shaft 53 is screwed into this left-hand threaded portion 54A.
The left fingers 55A are guided in parallel by A and 53B, and the guide shafts 53A and 53B are screwed into the right threaded portion 54B.
When the screw shaft 54 rotates, the right fingers 55B guided in parallel by the right fingers 55B are moved in parallel so as to approach or separate from each other with the joint between the left screw portion 54A and the right screw portion 54B as the center of movement. Through this parallel movement, the workpiece 20 shown in FIG. 1 is gripped or clamped.

A pulley 60 and a tapered hole 61A are attached to one end of this screw shaft 54.
A motor pulley 65 is fixed to the rotating shaft of the servo motor 56, and a belt 64 having meshing teeth is connected between the pulley 60 and the motor pulley 65. The rack is stretched to prevent slipping.

An encoder disk 57A that detects the amount of rotation of the rotation shaft is fixed to the other end of the rotation shaft of the servo motor 56, and a detector (not shown) provided on the encoder 57 detects the rotation angle pulse and rotation of the encoder disk 57A. The sensor is configured to detect an amount pulse.

FIG. 4 is a waveform diagram showing the rotation angle pulse and rotation amount pulse of the encoder disk 57A. One pulse is generated for each rotation of 57A.

In this way, the rotation amount and rotation angle of the rotation shaft of the servo motor 56 can be detected.

Referring again to FIG. 3, the side plate 52B includes an air cylinder 63 that is driven up and down by air pressure and vacuum pressure supplied through piping 66, and an air cylinder 63 that is connected to this air cylinder 63 and driven up and down as shown by arrow U in the figure. A bin 62 in which the contents are stored is provided.

This bottle 62 is inserted into a tapered hole 61A of a disk 61 fixed to a screw shaft 54.
4 cannot be rotated.

Further, a flange 51 is provided on the upper part of the base 52, which acts as an engaging member when attached to the shank body 4, and an air piping connector 59 and an electrical connection connector 58 built in the flange 51 are provided. is connected automatically when it is engaged with the shank body 4, and control and drive electric signals sent from the main control section 3, as well as air pressure and vacuum pressure are supplied to the robot hand 5. I have to.

Next, FIG. 5 shows a table stored in the storage device Mm and the common memory 304 after writing. Fifth
FIG. 5A shows fingers 55 that are moved to grip dimensions of a workpiece WN, each of which has a different grip portion size.
This is a first table in which the number of pulses PN corresponding to the driving positions of A and 55B is written, and is stored in the aforementioned storage unit Mm.

FIG. 5(b) shows the screw shaft 54 on the robot hand 5 mentioned above.
This is a second table in which the number of pulses Qs corresponding to the position where the disk 61 fixed to the disk 61 is locked and cannot rotate is written, and is similarly stored in the storage unit Mm described above.

FIG. 5(C) shows the fingers 5 corresponding to each of the workpieces WN.
Pulse number R corresponding to the separation drive position of 5A and 55B
This is the third table in which N is written, and is stored in the aforementioned storage unit Mm.

Here, to obtain this pulse number Rs, the above pulse number P
From N, the number of pulses Q2 and the number of pulses Q M+ 1 (however, 0.
u < P N < QM-1), the smaller one of the absolute values obtained by subtracting QM or Q &1* + is written as the pulse number R, and the finger 55A, 5
The amount of drive of 5B is made to be the minimum.

Here, to explain an example with specific numerical values, in order to grip the workpiece W, the number of pulses Pl is required to be 80 pulses, and the disk 61 fixed to the screw shaft 54 becomes unrotatable. The first number of pulses Q1 corresponding to the position where the disk 61 is made to rotate is 50 pulses, and the second number of pulses Q2 at which the disk 61 is made unable to rotate is 100 pulses. The number R+ is calculated as follows: 150-801<l Based on the result of 100-801, 100 pulses will be written as R8. In this way, the RNs corresponding to all the works WN are written in the storage section Mm in advance.

The operation of the robot apparatus configured as described above will be explained with reference to the flowchart of FIG. 6 and FIG. Proceeding to S2, the CPU device 301 reads the number of pulses R2 closest to the grasping position of the next workpiece W2 from the storage unit Mm, and proceeds to Step S3, setting the read pulse number R2 as a target value in the common memory 304. Write to storage area.

Next, the CPU device 301 uses the common memory 3 in step S4.
A command write operation to "drive a finger" is performed in the command area in 04.

With the above, the operation performed by the CPU device 301 is completed, and then the process proceeds to step S5, where the servo module 302 reads the instruction to "drive the finger" written in the command area in the common memory 304, and then Proceeding to step S6, the number of pulses R2 read out in step S3 is read into the storage unit MS in the servo module 302 as a target value.

Then, in step S7, the servo module 302
The above-mentioned deviation counter 30 is applied to the driver device 303 that drives the servo motor 56 until the pulse number R2 reaches rOJ.
2a continues to output the speed command. As a result,
Finger 55A.

55B will be moved to the position closest to the next workpiece W2.

Next, in step S8, this sir module 30
2 clears the "drive finger" command set in the command area in the common memory 304 and restores the common memory 304 to its initial state.

Next, since the common memory 304 has been set to the initial state in step S9, the CPU device 301 determines that driving of the fingers has been completed, and proceeds to step SIO, and sends air pressure to the air cylinder 63 to move the bin 62 into the screw shaft. The rotation of the screw shaft 54 is regulated by inserting it into the tapered hole 61Δ of the disk 61 fixed to the screw shaft 54.

In this way, after the rotation of the screw shaft 54 is regulated and the left finger 55A and right finger 55B are fixed at a position close to the outer dimension W2 of the workpiece 2o, step S15
At the same time as the advanced robot hand 5 is removed from the shank body 4, the holding section 30A of the robot hand stocker 30
It will be held in one of the following. Then, another type of robot hand is attached to the shank body 4, and the robot moves to the next operation (not shown).

Then, when the work using the robot hand 5 starts again, after removing the robot hand from the shank body 4, the CPU device 301 proceeds to step S12 and attaches the robot hand 5 to the shank body 4J. Next, in step S13, vacuum pressure is applied to the air cylinder 63, the bottle 62 is pulled out from the tapered hole 61A, and the screw shaft 54 is made freely rotatable.

Then, in step S14, the CPU device 30'f reads out the number of pulses R2 from the storage unit Mm, proceeds to step S15, and writes the number of pulses R2 in the current position area of the shared memory 304, while Perform initialization. Finally, the process proceeds to step S16, and the normal gripping operation is resumed.

By operating as explained above, the left finger 5
It is no longer necessary to set the origin each time the robot hand 5A and right finger 55B are attached, and the left finger 55A and right finger 5 are immediately moved to the gripping position of the next workpiece after attaching the robot hand.
5B will be able to migrate.

On the other hand, if more precision than the case described above is required, the method of inserting the bin 62 described above
．． Since there is an insertion angle error of 3 degrees, backlash etc. cannot be avoided.

Therefore, in order to avoid this angle error, after removing the bin 62, the encoder 57 generates the 1
There is a method of detecting a rotation amount pulse output for each rotation to perform accurate positioning.

To explain an example of such a method, the encoder plate 57. If the rotation amount of A is M and the number of pulses per rotation of encoder plate 57A is A, the rotation amount pulse is A-M (
(M is an integer) will be detected as the pulse number, so I
The pulse number Zs of the rotation amount pulse that minimizes the value of RN A-M l is stored in advance, and further, after this pulse is attached to the robot body, the rotation amount detection means of the encoder plate 57A detects it. Servo motor 56 in advance
There is a method of providing a table in the storage unit Mm that also determines the rotation direction of the rotation direction.

FIG. 7 shows a table in which the number of rotation pulses zN that minimizes IRN-A-M+ and the forward and reverse rotation directions of the servo motor 56 are also determined so as to detect this pulse number ZN at an early stage. It is something that

FIG. 8 shows a flowchart of an example of the flow used when more precision is required, and the flow up to step S12 is almost the same as the flow shown in FIG. Although omitted, in FIG. 8, when the bin 62 is removed in step S12, the process advances to step S13, where the forward and reverse rotation directions of the servo motor 56 are read out from the memory section Mm.Next, in step S14, the forward and reverse rotation directions of the servo motor 56 are read out. Or if the reverse rotational drive is performed, step S15
Then, the pulse number ZH of the rotation amount pulses that minimizes JR, -A-M+ is detected.

Therefore, in step S16, the value of Zs is stored in the common memory 30.
While writing this pulse number ZN in the current position area within 4,
Initialization of the work is performed.

Finally, the process advances to step S17 and the normal gripping operation is resumed.

By operating as explained above, there is no need to set the origin of the attachment of the left finger 55A and right finger 55B, and after the robot hand is attached, the fingers are positioned with high precision and can be immediately started for the next work. be able to migrate.

Next, FIG. 9 is a plan view showing another configuration of the robot hand 5 shown in FIG. 3, and shows a configuration applied when the positioning accuracy is relatively low.

The basic configuration is the same as the robot hand 5 shown in FIG. 3, so only the differences will be described. A brake rod 68 is connected to an air cylinder 63 and slides in the vertical direction indicated by arrow V in the figure. A brake material 68A is provided at the tip of the screw shaft 54, and this brake material 68A comes into contact with the outer circumferential portion of the screw shaft brake portion 54C of the screw shaft 54, and when air pressure is sent into the air cylinder 63, the screw Axis 5
4 will be restricted from rotating.

With this configuration, work using the robot hand 5 is performed when the positioning accuracy is relatively low.

In the embodiments described above, the air cylinder was only driven by pneumatic pressure, but an electromagnetic solenoid may also be used.In addition, in the embodiments described above, only a single-axis drive example was described to simplify the explanation. Naturally, this can also be applied to a robot hand that is driven by multiple axes, and in this case, the time reduction becomes even more remarkable, and the original purpose of the present invention is to It is applied to the hand.

Furthermore, in the embodiments described above, only an example was explained in which a servo motor was used as the finger drive means, but oven control drive is possible, and a pulse motor that maintains the rotation axis at a predetermined angle state when not energized is used as the finger drive means. When used as a driving means, the above-mentioned engagement means pin 63 may be omitted.

[Effects of the Invention] As explained above, the robot device of the present invention shortens the recovery time required when reattaching the detachable robot hand to the robot body, and increases the processing capacity of the robot device. can be improved.

[Brief explanation of the drawing]

FIG. 1 is an external perspective view showing an embodiment of the robot device of the present invention, and FIG. 2 is a control means 3 of the robot device shown in FIG.
3 is a front view of the first embodiment of the robot hand 5, FIG. 4 is a waveform diagram of the encoder 57 provided in the robot hand 5 of FIG. 3, and FIG. 5 is a storage section. FIG. 6 is a flowchart showing an example of the operation of the robot device; FIG. 7 is a diagram showing the tables stored in the memory Mm; FIG. 8 is the robot device FIG. 9 is a front view showing another configuration of the robot hand 5. In the figure, 2... robot body, 3... main control section, 4...
...Shank body, 5...Robot hand, 6...Single support arm, 7...Z-axis motor, 8...Y-axis motor, io-...X-axis motor, 11...table, 12・
... Cable, 13... Pallet, 14... Pallet holder, 15... Holder, 20... Work, 21
...Assembly, 25...Near compressor, 30...
・Robot hand stocker, 51...flange, 52
... Base, 53A153B ... Guide shaft, 54.
...Screw shaft, 56...Servo motor, 57...Encoder, 6o...Pulley, 61...Disc, 61
A...Tapered hole, 62...Bin, 63...Air cylinder, 64...Belt, 65...Motor pulley,
66... Piping, 68... Brake rod, WN... Workpiece external dimensions, PN%QM, R, %ZN... Number of pulses, 300... Control means, 301... CPU device, 3
02...Servo module, 302a...Deviation counter, 303...Driver, 304...Shared memory, Mm%Ms...Storage unit. Figure 5 Figure 7 Soil Figure 8

Claims (4)

[Claims] (1) A robot device comprising at least two robot bodies and at least two robot hands that are removably attached to the robot body and have at least two fingers that are movable for gripping a workpiece. After the robot hand is attached to the robot body and the workpiece gripping operation is completed, the robot hand moves the fingers to the vicinity of the gripping position of the next workpiece to be gripped, and then the robot hand A robot device characterized in that the robot hand is detached from the robot hand. (2) The robot hand includes a finger driven by a drive means and a locking means for locking the drive means, and the robot body includes a storage means for storing the amount of drive of the drive means, When the robot hand is separated from the robot body after being driven,
The robot apparatus according to claim 1, wherein the locking means holds the drive means in a locked state. (3) The storage means stores workpiece pulse information P_N of the finger position corresponding to each of the workpieces, locking pulse information Q_M corresponding to the locking position of the locking means, and the workpiece pulse information P_N. Stop pulse information Q_M,
3. The robot apparatus according to claim 2, further comprising a table for storing pulse information R_N composed of the smaller absolute value among those obtained by subtracting Q_M_+_1. (4) When the amount of rotation of the driving means of the finger is M and the number of pulses per rotation is A, the pulse information R
A table that determines the number of pulses Z_N that is closest to _N and minimizes the value of |R_N-A・M|, and the forward and reverse rotation directions of the driving means so as to detect the number of pulses Z_N early. 3. The robot device according to claim 2, wherein the storage device is provided with:.