CA1074832A

CA1074832A - Cooperative drive robot

Info

Publication number: CA1074832A
Application number: CA298,960A
Authority: CA
Inventors: Kenro Motoda; Kensuke Hasegawa
Original assignee: Motoda Electronics Co Ltd
Current assignee: Motoda Electronics Co Ltd
Priority date: 1977-03-17
Filing date: 1978-03-15
Publication date: 1980-04-01
Also published as: FR2383758B1; DE2811263C2; PL205352A1; IT7848437A0; DD136364A5; NL173610C; NL173610B; DE2811263A1; GB1602213A; IT1155884B; FR2383758A1; CS212704B2; HU180267B; NL7802955A

Abstract

COOPERATIVE DRIVE ROBOT

ABSTRACT OF THE DISCLOSURE
It is essential for a robot adapted to carry a load such as an article, a tool or a cargo that it is simple in construction and yet it can accurately carry the load to a specified position. For this purpose, hereto-fore, one robot has a variety of capabilities and func-tions. In this invention, the capabilities and functions of the robot are separately assigned to a plurality of robots in such a manner that the capabilities of the robots are mutually complemented to perform a given operation.

Description

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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 dap/~

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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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~o7~1~3 2 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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~0~32 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 ~7~832 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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~o7~33;z 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. ~.

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A cooperative drive robot arrangement for moving a load to a desired position, said robot arrange-ment comprising:
a main robot including a load holding section means for actively moving said holding section in opposite substantially rectilinear directions, and means for enabling said moving means to be passively moved in directions parallel to a plane transverse to said rectilinear directions, said main robot being free of means for actively moving said moving means or said holding section in directions parallel to said plane;
at least one sub robot including a guide device within said plane, and a drive device mounted on said guide device for active movement therealong in direct-ions within said plane, said drive device being pre-vented from movement relative to said guide device in said rectilinear directions; and connecting means for flexibly connecting said holding section to said drive device such that said holding section is actively moved by said drive device in directions parallel to said plane, thereby enabling said moving means of said main robot to be passively moved in directions parallel to said plane, and such that said holding section is passively movable with respect to said drive device in said rectilinear directions upon active movement of said holding sec-tion in said rectilinear directions by said moving means of said main robot.

2. A robot arrangement as claimed in claim 1, wherein said main robot further includes a base, said means for actively moving said holding section comprises an arm member extending outwardly from said base, said arm member having a first end connected to said holding section and a second end pivotally connected to said base for rotation about an axis extending parallel to said rectilinear direction.

3. A robot arrangement as claimed in claim 2, wherein said guide device comprises first and second par-allel spaced rails within said plane, and a third rail extending between and transverse to said first and second rails within said plane, and said drive device comprises means at opposite ends of said third rail for driving said third rail along said first and second rails in opposite directions extending parallel thereto, and drive means movable mounted on said third rail for movement there-along in opposite directions extending parallel thereto.

4. A robot arrangement as claimed in claim 3, wherein said connecting means comprises a contraction mechanism having a first end connected to a bottom portion of said drive means and a second end connected to a top portion of said holding section.

5. A robot arrangement as claimed in claim 3, wherein said connecting means comprises a longitudinal rod having a first end connected to said first end of said arm and a second end connected to said holding sec-tion, said rod extending through said drive means for sliding movement relative thereto in said rectilinear directions.

6. A robot arrangement as claimed in claim 2, wherein said guide device comprises a longitudinal rail mounted within said plane, and said drive device comprises drive means movable mounted on said rail for movement therealong in opposite directions extending parallel there-to.

7. A robot arrangement as claimed in claim 6, wherein said connecting means comprises a contraction mechanism having a first end connected to a bottom portion of said drive means and a second end connected to a top portion of said holding section.

8. A robot arrangement as claimed in claim 6, wherein said connecting means comprises a longitudinal rod having a first end connected to said first end of said arm and a second end connected to said holding section, said rod extending through said drive means for sliding movement relative thereto in said rectili-near directions.

9. A robot arrangement as claimed in claim 1, wherein said main robot further includes a vertically extending base having a vertical axis, said guide device comprises a guide rail extending in said plane orthogonally of said base, said drive device comprises drive means movably mounted on said guide rail for movement there-along in opposite directions extending parallel thereto, said connecting means comprises an expansion member depending from said drive means and supporting said hold-ing section, and further comprising a radial rail extend-ing horizontally radially from said base, said radial rail having a first end pivotally connected to said base for rotation about said vertical axis, and means flexibly connected to said drive means and mounted on said radial rail for radial movement therealong,for, upon movement of said drive means along said guide rail, causing said radial rail to rotate about said axis.