Note: Descriptions are shown in the official language in which they were submitted.
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B~CKGROUND OF THE INVENTION
This invention relates to cooperative drive robots.
A conventional robot for moving a heavy load such
as an article, a tool, or a cargo ~o a des:ired position has
a rotatable driving box mounted on the upper portion of a
pole erected on a truck, and hori~ontal arms forming a
parallelogram link mechanism coupled through a balancing
spring to the box. A vertical arm extends downwardly from
one end of the horizontal arms and a holding section for
hold~ng a load is provided at the lower end of the ver~ical
arm. The load can be held by closing a holding member
provided on the bottom of the holding section. The circular
movement of the robot, the vertical and horizontal movements
and circular movement of the holding section, as well as the
openlng and closing operatlons of the holding member are
controlled by a control unit. This control unit is employed
to move the holding section vertically and/or horizontally
to carry the load to a specified position in accordance with
position da~a from a preset program or a computer. However~
~he weight of the load is not always coastant, and ~herefore
the horizontal and vertical arms nay be somewhat bent because
of such variations in weight and in moving speed. Therefore,
even if the holding section i8 moved in accordance wlth the
position data specified9 the actual position of the load
carried by the holding section may be different rom the
specified position.
The circular motlon o,~the driving box i9 one of ~;
the factors which will lower the positional accuracy because
~there is a distance between ~he driving section and the holding
sec~ion. In other words, in carrying a load by holding it
with the arm of ~he conventional robotg the arm is tulled by
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applying a driving force to the base of the arn~. Accordingly,
it is difficult to accurately carry the load to the specified
position because of the bending5 inertia, circular motion
of the arm.
Furthermore, in the case where the distance between
the holding section and the driving section at the base of
the arm is great as in the conventional robot, it i5 necessary ;~
to increase the structural strength of the arm as well as the
driving power, which leads to increases in the inertia and
the si~e of the robot. This is another disadvantage of ~he i
conventional robot.
In addition, in the case where it is required to
lift and carry a load and to place it at a specified position
with hlgh accuracy, heretoPore one robot is used, and a
position instruction obtained through intricate correctio~
calculation in a computer or the like is issued to ~he robot.
Accordingly, the robot control system is necessarily intricate
and expensive.
Moreover, depending on the position of the load,
it is required to contral the holding direction of the holding
section which is the hand of the robot. If it is necessary
to maintain unchanged the holding direction of the holding
section, the direction control must be carried out by intricate
calculatlon. This i8
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an additional drawback accompanying the conventi~nal
robotO
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Accordingly, the present invention over-
comes the problems of the prior art by providing a co-
operative drive robot arrangement for moving a load to
a desired position, the robot arrangement comprising:
a main robot including a load holding section,
means for actively moving the holding section in opposite
substantially rectilinear directions, and means for enabl-
ing ~he moving means to be passively moved in directions
parallel to a plane transverse to the rectilinear directions, .
the main robot being free of means for actively moving
the moving means or the holding section in directions
parallel to the plane;
at least one sub robot including a guide device
within the plane, and a drive device mounted on the
guide device for active movement therealong in direc~-
ions within the plane, the drive device being prevented
from movement relative to the guide device in the rec-
tilinear directions; and
connecting means for flexibly connecting the hold-
ing section to the drive device such tha-t the holding
section is ackively moved by the drive device in direct-
ions parallel to the plane, thereby enabling the moving
.
means of the main robot to be passively moved in direct-
ions parallel to the plane, and such that the holding
section is passively mvvable with respect to the dri~e
device in the rectilinear directions upon active move-
ment of the holding section in the rectilinear direct-
ions by the moving means of the main robot. - .
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The novel features which are considered character- :
istic of this invention are set forth in the appended claims.
This invention itself, however~ as well as other objects
and advantages thereof will be best understood by reference
to the following detailed description of illustrative embodi-
ments, when read in conjunction with the accompanying
drawings. ~ .
BRIEP DESCRIPTION OF THE DRAWINGS :
In the accompanying drawings: ~
FIG. 1 is a perspective view for a description of .
the outline of a conventional robot;
FIGS. 2 through 6 are perspective views showing ~ ; -
various embodiments of this invention, and -
FIG. 7 is a perspective view showing an application
of the invention~
DETAILED DESCRIPTIO~ OE' THE INVENTION
A first example of a cooperative drive rvbot
according to this invention is shown in FIG. 2. A guide device
20 for guiding the hoFizontal movement of a holding
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section 8 of a first robot A (hereinafter referred to as
l~a main robot A" when applicable), and a drive control
device 40 for running the holding section 8 in a hori-
zontal direction for~ a second robot B (hereinafter
referred to as l~a sub robot B" when applicable). The
holding section 8 is moved in a vertical direction by
the main robot A and in a horizontal direction by the
sub robot B systematically coupled to the main robot A,
so that it can be moved accurately to a specified posi-
tion with a simple mechanism.
The guide device 20 of the sub robot B comprises
four posts 21 through 24 erected at four points fonming
a rectangule, four guide rails 25 through 28 mounted on
these four posts~ and a running rail 29 adapted to run
along the parallel guide rails 26 and 28. Running wheels
30 and 31 are provided at both ends of the running rail
29 so that the latter can straightly (in the direction-
X~ run along the guide rails 26 and 28. On ~he other
hand, the drive control device 40 of the sub robot B
comprises a drive truck 41 adapted to straightly (ln the
direction Y) run along the rulming rail 299 an expansioa
and contraction mechanism 42 fixedly secured to the
bottom of the drive truck 41 and to the holdlng section
8 of the main robot A at both ends and systematically
coupling the robots A and B, a running drive means pro-
vided in the drive truck 41 for driving the latter~ and : :
running drive means provided in ~he running wheels 30
and 31 ~or driving ~he latter~ The guide device 20 of : :
the sub robot B are so designed and arranged that a load
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can be carried in a predetermined ran8e (or area) in
compliance with the working range intended by the robot.
In this example, the load is carried below the guide ~ :
device 20. : .
The vertical movement of the holding section 8 is
carried out by driving a driving box 3 of the main robot
A in response to an instruction signal from a control
box. In this operation, the expansion and contraction
mechanism 42 is expanded or contracted passively in res- ...
ponse to the actlve vertical movement of the holding . ~ .
section 8 caused by the main robot A. On the other hand,
the holding section 8 is moved in a horizontal direction
as the running wheels 30 and 31 and the drive truck 41
are straightly run along the guide rails 26 and 28 and
the running rail 299 respectively, by applying position
and speed date from the control box to the drive contol
device 40 of the sub robot B. In other words, as the
drive truck 41 is actively straightly driven in the
direction X-Y, the holding seceion 8 is passively moved
in the same direction through the expansion and contrac- .
tion mechan.ism 42 which forms one unit with the drive
truck 41. Thus, the horizontal movement of the holding
section 8 is carried out without turning the main robot .-.
Ao The main robot A bears the weight of the load, while
the sub robot B takes care of the movement of the load.
As is apparent from the above description, in the -:
cooperatlve drive robot, the capability and function of
the robot ls divlded into two parts; that is, the main
.
robot A takes care of the lifting operatlon and mainly
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supports the weight of the load, while the sub robot B
takes care of the horizontal movement alld mainly the
load carrying operation. As the two robots A and B are
systematically combined together as ~as described above~,
the load can be carried to a desired position with high
accuracy~ Furthermore, according to the invention, the
end o the arm, adapted to hold a load, of the main
robot is straightly moved while being guided by the
guide device of the sub robot. ~herefore, the load can
be more accurately carried to the desired position with-
out using circular movement. In addition, the influence
due to the bending and inertia of the arm can be elimi-
nated, and the driving power can be reduced.
The guide device 20A of the sub robot B, as shown
in FIG. 3, may be secured dlrectly to the pole 2. More
specifically, two stationary arms 35 and 36 horizon~ally
open in the fonm of a sector are secured to the upper
portion of the pole 2, and a straight guide bar 37 is
connPcted to the ends of the stationary arms 35 and 36.
A drive control device 40A is moun~ed on the guide bar
37 in such a manner that it can strightly slide along
the guide bar 37. Furthermore, an expansion and contrac-
tion mechanlsm 46 having a rotatable fixing part is
secured to the bottom of a running truck 453 and the
holding section 8 of the main robot A is secured to the
mechanism 46. In this case, theilifting work is active-
ly carried out through the expansion and contraction
mechanism 46 by the main robot A, while the carrying
work in the direction X-X~ is passively efected by ;
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straightly driving the running truck 45 of the sub robot
B. In this case also, the load can be carried to a
desired position with high accuracy.
In this connection, if the two stationary arms are
made to be rotatable as one unit on the pole 2 or the
pole 2 itself is made to be rotatable, the load carry- .
ing work can be effected at a given position around the
robot.
The same effect can be obtained by fixedly securing
a guide device 20B of the sub robot B such as shown in
FIG. 2 through mounting arms 50 and 51 to the pole 2
and by controlling the lifting operation from above the
guide device 20B by the main robot A, as shown in FIG.4.
In this example, running rails 29A and 29B are extended
in parallel in the direction Y9 and the holding section
8 of the main robot is moved vertically through the space
between the two running rails 29A and 29B. .
Another example of the cooperative drive robot is ~
shown in FIG. 5, in which the hori~.ontal movement is .
carried out along two parallel guide rails 60 and 61 of
the sub robot B which are extended radially from the
upper part of the pole 2, and the vertical movement of
the holding section of the main robot A is effected
through the space between the guide rails 60 and 61~
Shown in FIG. 6 is another example of the cooperative
drive robct according to the invention, in which the
main robot according to the invention, in which the
main robot A and the sub robot B shown in FIGo 2 are
designed ~o as to be mounted on the celing or the like .~.;
in a working roomj and the lifting control drive is
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carried out above a guide device 20C of the sub robot B,
while the carrying operation is effected below the guie
device. In this connection, the cooperative drive robot
may be so designed that the main robot A and the sub
robot B are moved along rails provided on the celing or
the like.
In the above~described examples, ~he holding section
8 of the main robot A is moved vertically by means of
the expansion and contraction mechanism (42~ 42A and 46);
however, if the holding section is fixedly fastened to
the drive truck 41 or the running truck 45 of the sub
robot B, the holding member 9 may be moved vertically by
means of a rope or a chain. Furthermore~ in the above-
described examples, only one sub robot is employed, how-
ever, the invention is not limited thereto or thereby;
that is, three robots or more can bè combined together.
In addition, it goes without saying that in any of the
above-described examples, the same effects can be obtained.
Another example of the cooperative drive robot
according to the invention in which a robot such as
described above is provided with a coordinate conversion~
mechanism. Provided on the top portion of a pole 101 is
a rotatable circular motion mechanism 102, to one side of
which a straightly extended guide rail 103 is fixedly
serured. A running drive device 105 for running radial
Iy with respect ~o the pole 101 is~hung through running
wheels 104 on the guide rail 1033 and a circular motion
mechanism 106 is rotatably connected to ~he bottom of
~he running driv~ device 105. Fur~hermore, a guide rail
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109 is connected through two arms 107 and 108 to the upper
portion of the pole 101. A running dri~e device 110 is
connected to the lower portion of the circular motion mechanism
106 in such a ~anner that it can run along the guide rail
109. A holding section 112 is coupled through a folding
expansion and contraction mechanism 111 to the lower
portion of the running drive mechanism 110.
In opcration, a load held by the holding section
112 is moved vertically (Z-~) by means of the expansion
and contraction mechanism 11, and is also moved in the
direction (Y-Y~) by the running operation, along the
guide rail 109~ of the running drive device 110~ When
the running drive device 110 runs along the guide rail .
109~ the guide rall 103 is turned ~ ) through
the circular motion mechanism 102 by the circular motion
(~2 ~ ~2~ of the circular motion mechanism 106~ while
the running drive device 105 is moved slightly in the
direction X-X~. As the running drive device 105 runs ~:
along the guide rail 103, the load held through the ex- ~ :
pansion and contraction mechanism of the running drive
device 110 by the holding section 102 is moved in the
direction X-X~. In any of the above-described load move~
ments, the holding section 112 provided through the ex- ~
pansion and contraction mechanism is maintained in one : :
and the same direction (facing the pole 101; more specifi~
cally~ facing in a direction perpendicular to the guide
rall 109)~ Accordlngly~ the robot according to the
i~vention is suitable for a case where, for instance,
alighned loads are to be piled one another in alig~ment
state. ~.
