U.S. patent application number 14/733657 was filed with the patent office on 2015-12-10 for robot apparatus.
The applicant listed for this patent is CANON KABUSHIKI KAISHA. Invention is credited to Shinsuke Iizuka.
Application Number | 20150352720 14/733657 |
Document ID | / |
Family ID | 53373329 |
Filed Date | 2015-12-10 |
United States Patent
Application |
20150352720 |
Kind Code |
A1 |
Iizuka; Shinsuke |
December 10, 2015 |
ROBOT APPARATUS
Abstract
A plurality of robot arms are each provided with indication
devices that have indicators which indicate operability states of
at least one other robot arm different from the robot arm on which
the indication device is provided. Alternatively or in addition,
the indication devices have indicators which indicate operability
states of a respective robot arm upon which the indication devices
are provided. Robot control devices which control operations of the
robot arms communicate through a LAN to share information regarding
the states of the robot arms. Indication drive signals for the
indication devices are generated based on states of servo control
signals and/or brake control signals for the robot arms.
Inventors: |
Iizuka; Shinsuke;
(Kawasaki-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
CANON KABUSHIKI KAISHA |
Tokyo |
|
JP |
|
|
Family ID: |
53373329 |
Appl. No.: |
14/733657 |
Filed: |
June 8, 2015 |
Current U.S.
Class: |
700/245 ;
414/730; 74/490.01 |
Current CPC
Class: |
G05B 2219/24092
20130101; Y10T 74/20305 20150115; B25J 9/1664 20130101; B25J 9/1674
20130101; B25J 9/0084 20130101; B25J 9/1682 20130101 |
International
Class: |
B25J 9/16 20060101
B25J009/16; B25J 19/00 20060101 B25J019/00; B25J 9/00 20060101
B25J009/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 10, 2014 |
JP |
2014-119369 |
Claims
1. A robot apparatus comprising: a plurality of robot arms each
including an indication device having a first indicator configured
to indicate an operation state of at least one of the plurality of
robot arms different from a respective robot arm on which each
indication device is provided.
2. The robot apparatus according to claim 1, wherein the indication
device of each arm has a second indicator configured to indicate an
operation state of the robot arm where the indication device is
provided.
3. The robot apparatus according to claim 1, wherein each of the
robot arms includes a tip part and the indication device of each
arm is provided at the tip part.
4. The robot apparatus according to claim 1, wherein the plurality
of robot arms are a plurality of juxtaposed robot arms.
5. The robot apparatus according to claim 1, further comprising,
for each of the robot arms, a robot control device configured to
control an operation of a respective robot arm, wherein the robot
control devices communicate over a network to share information
regarding the operation states of the robot arms.
6. The robot apparatus according to claim 1, wherein the operation
states of the robot arms indicated by the indication device is an
operability state indicating whether the corresponding robot arms
are operable or not.
7. The robot apparatus according to claim 1, wherein an indication
drive signal for each of the indication devices is generated based
on a servo control signal which controls a servomotor which drives
a joint of each corresponding robot arm.
8. The robot apparatus according to claim 1, wherein an indication
drive signal for each indication device is generated based on a
brake control signal which controls a brake which controls an
operation of a joint of each corresponding robot arm.
9. The robot apparatus according to claim 8, wherein the brake
control signal is derived from a joint of a robot arm having a
brake controlled by the brake control signal and is converted, by
the indication control device provided near the joint, to an
indication drive signal to be used in the indication device.
10. The robot apparatus according to claim 1, wherein each
indication device has an indication surface across at least a half
circumference of a tip part of a respective robot arm.
11. The robot apparatus according to claim 1, wherein each
indication device is provided on a tool provided in a tip part of a
respective robot arm for handling an object.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a robot apparatus having a
plurality of robot arms.
[0003] 2. Description of the Related Art
[0004] In recent years, automation of processes for assembling an
industrial product having a small and complicated structure, for
example, has been highly demanded, and such products may require
high speed and highly precise assembly using a small industrial
robot. From a viewpoint of competitiveness over foreign production,
for example, a cost-reduced production system must be constructed,
and a high speed, highly precise, stable and highly productive
production line has been demanded in which one robot is responsible
for many assembly processes.
[0005] In some highly efficient production lines, multiple (or a
plurality of) industrial robot arms may be used to precisely
assemble parts each grasped by fingers of each of the arms into a
part on a workbench. In order to teach a robot an assembly job in
such a robot system, a plurality of teachers may sometimes be
involved. For example, such a teaching work may involve an operator
who operates a robot arm by using a teaching device such as a
so-called teaching pendant, and an operator who visually inspects
parts to monitor conditions and failure/success of an assembly job
thereon. The former operator may sometimes be called a
"manipulator", and the latter operator may sometimes be called a
"supervisor".
[0006] A robot arm to be subjected to a teaching operation in a
robot apparatus having a plurality of arms is decided based on an
oral communication between the supervisor and the manipulator. A
robot arm subjected to a teaching operation will be called a
"decided arm" hereinafter.
[0007] In a teaching operation on a decided arm, a supervisor waits
in the vicinity of the decided arm and concentrates his or her gaze
and attentions on fingers of the decided arm. In this case, because
a result of an operation performed on the decided arm by a
manipulator is only displayed on a teaching pendant (hereinafter,
called a TP), the operability state of the operation on the arm is
not directly available to the supervisor.
[0008] The expression "operability state" herein refers to a state
that a specific manipulation (such as a jog operation or an inching
operation to be performed by using a TP) is enabled to start an
operation of a robot arm immediately or not. Generally, a teaching
operation may be performed on a robot arm by manipulating a TP to
actually operate a robot arm from a present position/attitude to a
next teaching point. Such a teaching operation may be allowed by
performing a specific manipulation on a TP to shift the TP (or the
entire robot system) to a mode which enables a teaching operation
(teaching mode, which will be described below), for example.
Alternatively, in a TP having an enable switch such as a deadman's
key (switch), the enable switch may be shifted to the enable state
to allow a teaching operation as a result.
[0009] For example, a mode shift or switch operation as described
above may be performed to shift the robot apparatus to a mode
allowing a teaching operation or a teaching mode. In the teaching
mode, a servomotor drives a joint, for example, of a robot arm to
shift to a so-called servo-ON state. In a case where a brake is
provided which locks a motion of each joint of a robot arm, the
brake of each joint is released from a locked state. The change
allows the robot arm to operate in accordance with a subsequent
teaching operation on a TP. In other words, the operability state
in the teaching mode is an enable state while it is a disabled
state in a mode excluding the teaching mode.
[0010] In the past, information exchange regarding an operability
state of a robot arm between a supervisor and a manipulator may be
performed through oral communication, for example. However, in this
configuration and operation forms, there is a possibility that a
manipulator may operate a robot arm without transmitting a signal
unintentionally, resulting in a collision of a decided arm with a
supervisor who does not expect the arm to move.
[0011] In view of such a situation, an indication control device
has been proposed which includes an indicator configured to
indicate whether an operation is possible or not on, or in the
vicinity of, a robot arm (see Japanese Patent No. 3183355, for
example). In a multiple-arm robot system disclosed in Japanese
Patent No. 3183355, an indicator is provided on (or in the vicinity
of) each of a plurality of robot arms so that the indicators may
indicate whether the corresponding robot arms are possible to
operate or not.
[0012] However, in the configuration of Japanese Patent No.
3183355, the operability state of a specific arm is only indicated
by an indicator provided on, or in the vicinity of, the arm. Thus,
in a case where an arm (hereinafter, called an undecided arm)
excluding a decided arm is shifted to a teaching mode, a supervisor
who concentrates on the decided arm may not notice the fact that
the undecided arm has been shifted to the teaching mode.
[0013] A case will be discussed in which, after teaching a decided
arm, a manipulator next shifts an undecided arm to a teaching mode
to teach the undecided arm, and unintentionally does not transmit a
signal that the mode of the decided arm is changed. In this
situation, the configuration of Japanese Patent No. 3183355 does
not allow a supervisor who concentrates on the decided arm to
easily notice that the undecided arm has been changed to the
teaching mode. This is because, in the configuration of Japanese
Patent No. 3183355, when a manipulator shifts an undecided arm to a
teaching mode, the fact that the undecided arm is in the teaching
mode is indicated by an indicator on the undecided arm outside the
supervisor's field of view and conscious mind. According to the
indication scheme as disclosed in Japanese Patent No. 3183355, it
is extremely difficult to notice that an undecided arm has been
shifted into a teaching mode as far as a supervisor sometimes
performs a behavior such as looking at an undecided arm.
[0014] The present invention allows indication of an operability
state of a robot arm through an indicator provided on another robot
arm of a plurality of robot arms in a robot apparatus.
SUMMARY OF THE INVENTION
[0015] The present invention provides a robot apparatus including a
plurality of robot arms each including an indication device having
a first indicator configured to indicate an operation state of at
least one of the plurality of robot arms different from a
respective robot arm on which each indication device is
provided.
[0016] Alternatively or furthermore, according to the present
invention, the indication device may have a second indicator
configured to indicate a state of a robot arm where the indication
device is provided.
[0017] Further features of the present invention will become
apparent from the following description of embodiments with
reference to the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 is an explanatory diagram illustrating a schematic
configuration of a robot apparatus according to a first embodiment
applying the present invention.
[0019] FIG. 2 is a perspective view illustrating a configuration
example of an indicator provided at a tip of a robot arm of the
robot apparatus in FIG. 1.
[0020] FIGS. 3A to 3D illustrate indication control in the
apparatus in FIG. 1, and FIG. 3A is a flowchart of indication
control relating to a teaching operation, FIGS. 3B and 3C are
explanatory diagrams illustrating indication states of an indicator
in steps of the indication control, and FIG. 3D is an explanatory
diagram illustrating indication control signals used in the
indication control.
[0021] FIG. 4 is an explanatory diagram illustrating a schematic
configuration of a robot apparatus according to a second embodiment
applying the present invention.
[0022] FIG. 5 is an explanatory diagram illustrating a different
wiring scheme in a robot apparatus according to the second
embodiment applying the present invention.
[0023] FIG. 6 is a signal block diagram illustrating detail
configurations of a driving control system and an indication
control system in the robot apparatus according to the second
embodiment applying the present invention.
[0024] FIGS. 7A to 7D illustrate indication control in the
apparatus in FIG. 4 to FIG. 6, and FIG. 7A is a flowchart of
indication control relating to a teaching operation, FIGS. 7B and
7C are explanatory diagrams illustrating indication states of an
indicator in steps of the indication control, and FIG. 7D is an
explanatory diagram illustrating indication control signals used in
the indication control.
[0025] FIG. 8 is a block diagram illustrating a configuration of a
robot control device applied in the robot apparatus in FIG. 1.
DESCRIPTION OF THE EMBODIMENTS
[0026] Aspects for embodying the present invention will be
described below in detail based on illustrated embodiments. Each of
the embodiments of the present invention described below can be
implemented solely or as a combination of a plurality of the
embodiments or features thereof where necessary or where the
combination of elements or features from individual embodiments in
a single embodiment is beneficial. Embodiments relating to a robot
apparatus having two robot arms will be described below, but the
number of robots or robot arms is not limited to two. Two or more
(or a plurality of) robots or robot arms may be provided.
First Embodiment
[0027] FIG. 1 is a general configuration of a robot apparatus 200
having robot arms 201 and 211 implementing the present invention.
The robot arms 201 and 211 may be six-axis (joint) vertical
articulated robot arms, for example, and each of the joints thereof
may be controlled to a desired position/attitude by performing
servo control over a servomotor provided in the joint.
[0028] Operations of the robot arms 201 and 211 are controlled by
robot control devices 202 and 212, respectively. Teaching pendants
(TPs) 203 and 213 are connected to the robot control devices 202
and 212, respectively. Operations of the arms may be programmed
through manual operations on the TPs 203 and 213 connected to the
robot control devices 202 and 212. For example, an operation for
moving reference positions (such as tool mount planes at tips) of
the robot arms 201 and 211 through desired paths may be programmed
by sequentially designating teaching points on the path by using
the TPs 203 and 213. Such a teaching point may be designated
through an operation for moving an arm from a present
position/attitude as a result of a manual operation on the TPs 203
and 213, for example.
[0029] Each of the TPs 203 and 213 may have a changing switch for
switching between a state that a manual operation for teaching a
corresponding one of the robot arms 201 and 211 is enabled and a
state that automatic driving based on teaching data is performed,
for example. Each of the TPs 203 and 213 has a teaching mode
instruction switch for shifting a corresponding one of the robot
arms 201 and 211 to a teaching mode. Each of the TPs 203 and 213
has an operation instruction switch for displaying an operation
instruction for a teaching operation on a display, for example,
provided on a corresponding one of the TPs 203 and 213.
[0030] The robot arms 201 and 211 may be six-degree of freedom
manipulators each having six rotary joints, for example. Each of
the robot arms 201 and 211 has a gripper as illustrated in FIG. 2
at its tip part as a tool for grasping a work to be operated. FIG.
2 illustrates a structure around a gripper 2011 provided at a tip
of the robot arm 201. The robot arm 211 also has a similarly
configured gripper at its tip.
[0031] The gripper 2011 in FIG. 2 has a finger 2011a for handling a
work at a gripper tip 2011b. The illustrated gripper 2011 has a
gripper tip 2011b having a substantially cylindrical cross-section
and a gripper base 2011c, and an actuator configured to open and
close the fingers 2011a is provided within them. The actuator
configured to open and close the fingers 2011a may be any arbitrary
actuator such as pneumatic and hydraulic actuators as well as a
motor and a solenoid. The gripper 2011 is mounted at a tip of a
robot arm for the purpose of carrying in and out a work to a
working area or assembling a grasped work into a different
work.
[0032] The gripper tip 2011b and finger 2011a being action units of
the gripper 2011 are pivotably supported about a tool mounted
surface of the robot arm 201. The gripper tip 2011b and finger
2011a may be driven to pivot by a servomotor internally provided in
the gripper base 2011c, for example. Alternatively, a driving
source for the pivoting may be provided on a tool-mounted side of
the robot arm 201.
[0033] As illustrated in FIG. 2, according to this embodiment, the
gripper 2011 of the robot arm 201 has an indication device 205
having indicators 205A and 205B as an operability indication
unit.
[0034] The indicators 205A and 205B may include a plurality of LEDs
206A and 206B arranged with a predetermined space therebetween and
a ring-shaped scattering plate covering those LEDs, for example.
When one or more of the LEDs 206A or 206B is driven to light up or
flash, light is scattered externally by the scattering plate
covering the LEDs. According to this embodiment, in this structure
as described above, indication surfaces of the indicators 205A and
205B are provided on all circumference of the gripper tip
2011b.
[0035] Therefore, for example, in a case where two operators, e.g.
a manipulator and a supervisor, as described above, perform
teaching operations, the supervisor in particular is allowed to
easily visually recognize the indication states of the indication
device 205 at any position in the vicinity of the robot arm 201.
The visible easiness of the indication device 205 does not vary
even when joints of the robot arm 201 are controlled to any
attitude, or when the gripper tip 2011b and finger 2011a are driven
to pivot in any manner.
[0036] The indication device 205 may be positioned on a
circumference of the gripper base 2011c. The indication device 205
may be provided at any position where the indication device 205 may
be easily visually recognized during a teaching operation and may
be provided on the robot arm 201 instead of on the gripper 2011,
without greatly requiring visible easiness for an operator
(especially a supervisor). For example, the indication device 205
may be provided at a position close to the tip of the robot arm
201.
[0037] According to this embodiment, the structures of the gripper
and indication devices in FIG. 2 are provided on the robot arm 211
in FIG. 1. To avoid complexity in FIG. 1, reference numerals
relating to the gripper are omitted. For example, an indication
device 215 having indicators 215A and 215B are only illustrated on
the robot arm 211 in FIG. 1 where it has an equivalent
configuration to that of the indication device 205 provided on the
gripper.
[0038] According to this embodiment, the indicators 205A, 205B,
215A, and 215B of the indication devices 205 and 215 are usable for
indicating states, especially operability states, of the robot arms
201 and 211. The indicators 205A and 205B on the robot arm 201 and
the indicators 215A and 215B on the robot arm 211 are placed
adjacent to each other such that the indications may be checked
simultaneously as illustrated in FIGS. 1 and 2.
[0039] Each of the first indicators 205B and 215B of the arms is
used for indicating a state of an arm different from the arm where
the indicator is provided, while each of the second indicators 205A
and 215A is used for indicating a state of the arm where the
indicator is provided. The different usages of the indicators may
allow an operator (especially a supervisor) to watch the tip of one
arm to visually recognize not only the state of the arms but also
the state of an arm different from the one arm at the same
time.
[0040] For example, each (first indicator) of the indicator 205B of
the robot arm 201 and the indicator 215B of the robot arm 211 is
used for indicating a state of the corresponding one of the robot
arm 211 and robot arm 201 different from the arm where the
indicator is provided.
[0041] Each (second indicator) of the indicator 205A of the robot
arm 201 and the indicator 215A of the robot arm 211 is used for
indicating a state of the corresponding one of the robot arm 201
and robot arm 211 where the indicator is provided.
[0042] For example, when the robot arm 201 is changed to the
teaching mode in response to a manipulation on the TP 203, the
indicator 205A of the robot arm 201 and the indicator 215B of the
robot arm 211 are turned on (or lighted). When the robot arm 211 is
changed to the teaching mode in response to a manipulation on the
TP 213, the indicator 215A of the robot arm 211 and the indicator
205B of the robot arm 201 is turned on. When both of the robot arms
201 and 211 are not in the teaching mode, all of the indicators are
turned off (not lighted). Such indication control may be
implemented through indication control devices 204A, 204B, 214A,
and 214B, which will be described below.
[0043] The robot control devices 202 and 212 configured to control
the robot arms 201 and 211 may be connected to a LAN 230, for
example. The LAN 230 is a local area network configured based on
IEEE-802.3 standard or other network standard, for example. In the
robot apparatus according to this embodiment, information regarding
states, especially operability states, of the robot arms 201 and
211 is network-shared over the LAN 230. Based on the shared
operability states, indications of the indicators 205A, 205B, 215A,
and 215B are controlled through the indication control devices
204A, 204B, 214A, and 214B. The information regarding the
operability states may be shared by accessing a shared memory space
in a Programmable Logic Controller (PLC), not illustrated,
connected to the LAN 230 by the robot control devices 202 and 212,
for example. Alternatively, the information sharing may be allowed
by exchange of packet storing information corresponding to the
operability states of the arms between the robot control device or
over the LAN 230 when the operability state of at least one of the
robot arms changes or intermittently. The access to a shared memory
space and packet exchange as described above may apply any
arbitrary network protocol as required.
[0044] Next, steps for controlling lighting of the indicators
performed by the robot control devices 202 and 212 through the
indication control devices 204A, 204B, 214A, and 214B will be
described in detail. As described above, the robot control devices
202 and 212 are connected to the LAN 230 and are thus allowed to
share information (or control information) regarding states of the
corresponding robot arms.
[0045] The indication control devices 204A and 204B of the robot
control device 202 in FIG. 1 control indications of the indicators
205A and 205B, respectively. The indication control devices 214A
and 214B of the robot control device 212 control indications of the
indicator 215A, 215B, respectively. Signal lines between these
indication control devices and indicators are provided within the
robot arms 201 and 211, for example, as indicated by the broken
lines in FIG. 1.
[0046] The indication control device 204A of the robot arm 201
controls the indication of the indicator 205A in accordance with
the operability state of the robot arm 201 as described above. On
the other hand, the indication control device 204B of the robot arm
201 controls the indication of the indicator 205B in accordance
with the operability state of the robot arm 211 different from the
robot arm 201. Thus, the indication control device 204A of the
robot arm 201 receives a signal regarding the operability state of
the robot arm 201 from the control device 202 and controls the
indication of the indicator 205A. The indication control device
204B of the same arm receives a signal regarding the operability
state of the robot arm 211 transmitted through the LAN 230 and
controls the indication of the indicator 205B.
[0047] The indication control device 214A of the robot arm 211
controls the indication of the indicator 215A in accordance with
the operability state of the robot arm 211 as described above. On
the other hand, the indication control device 214B of the robot arm
211 controls the indication of the indicator 215B in accordance
with the operability state of the robot arm 201 different from the
robot arm 211. Thus, the indication control device 214A of the
robot arm 211 receives a signal regarding the operability state of
the robot arm 211 from the control device 212 and controls the
indication of the indicator 215A. The indication control device
214B of the same arm receives a signal regarding the operability
state of the robot arm 201 transmitted through the LAN 230 and
controls the indication of the indicator 215B.
[0048] The signals for controlling the indication of the indicators
by the indication control devices 204A, 204B, 214A, and 214B in
accordance with the operability states thereof may be servo signals
for controlling servomotors in the joints of the robot arms 201 and
211, for example. For example, in the teaching mode of one robot
arm, all joints of the robot arm may be operated in accordance with
a manual operation on the corresponding teaching pendant. For the
operation, servomotors of the joints of the corresponding arm are
turned on/off (enable/disable) collectively in many cases.
Therefore, for example, the signals for controlling the indication
of the indicators by the indication control devices in accordance
with the operability states thereof may be servo signals (or servo
control signals such as so-called servo ON signals) for controlling
one (or all) of the servomotors of the joints.
[0049] According to this embodiment, it is assumed in the following
descriptions that the signals for controlling the indication of the
indicators by the indication control devices 204A, 204B, 214A, and
214B in accordance with the operability states thereof are servo
control signals. In this case, the indication control devices 204A,
204B, 214A, and 214B may be duty ratio (alternatively or further
voltage/current) conversion circuits, for example, configured to
convert a servo control signal to an indication drive signal which
may be input to the indicators of the indication devices 205 and
215.
[0050] FIG. 8 illustrates a fundamental configuration of the
control system including the robot control device 202 (or 212),
robot arm 201 (or 211), and TP 203 (or 213) in FIG. 1. The control
system in FIG. 8 includes a robot control device 2, a robot arm 1,
and a TP 3. The robot control device 2 and robot arm 1 in FIG. 8
correspond to the robot control device 202 (or 212) and robot arm
201 (or 211) in FIG. 1, and the TP 3 in FIG. 8 corresponds to the
TP 203 (or 213) in FIG. 1. FIG. 8 illustrates a LAN 30 as a network
corresponding to the LAN 230 in FIG. 1.
[0051] FIG. 8 only illustrates the main configurations of the robot
control device 2, robot arm 1, and TP 3, and the configurations of
the indication system for indication of operability states as
described above are omitted (to avoid complexity and improve
understanding).
[0052] A main control unit of the robot control device 2 includes a
CPU 501 configured by a general-purpose microprocessor, for
example. A ROM 502 storing a program for general control of the
robot apparatus, and a RAM 503 usable as a work area for the CPU
501 are connected to the CPU 501. An external storage device 504
may be provided as a storage device usable for input/output of
control data. The external storage device 504 may be a (removable)
HDD, SSD, or flash memory, for example, and may be used for
input/output of teaching (programming) data for the robot arm 1 and
control data for updating a program in the ROM 502. The components
above are connected via an internal bus, not illustrated. The CPU
501 is capable of communicating with the TP 3 through an interface
circuit 505a configured based on an arbitrary interface standard to
receive input of an operation state of the TP 3. The CPU 501
communicates with the LAN 30 through an interface circuit 506
configured based on the network standard and shares information
regarding states of robot arms as described above through the LAN
30.
[0053] Indication control in the aforementioned configuration will
be described with reference to FIGS. 3A to 3D. Here, indication
control over the indication device 205 (robot arm 201) and
indication device 215 (robot arm 211) will be described, for
example, in a case where the robot arm 201 is subject to a teaching
operation.
[0054] FIG. 3A illustrates a flow (step S0 to S4) of control in a
case where a manual teaching operation is performed on the robot
arm 201. FIG. 3A mainly illustrates operations principally from the
TP 203. The control over the components of the robot arm 201 in
response to operations in steps (S0 to S4) is executed by the CPU
501 (FIG. 8) in the robot control device 202. A control program to
be executed by the CPU 501 therefor may be stored in the ROM 502 in
FIG. 8, for example.
[0055] FIGS. 3B and 3C illustrate indication states of the
indication devices 205 and 215 on the robot arms 201 and 211 in
correspondence with the steps (step S0 to S4) in FIG. 3A. The
lighting states of the indicators 205A, 205B, 215A, and 215B in the
indication devices 205 and 215 are indicated by broken lines.
[0056] FIG. 3D illustrates changes of a servo control signal (left
side) and an indication drive signal (right side) in steps S0 to S4
in FIG. 3A. According to this embodiment, the indication states of
the indicators in the indication devices 205 and 215 are acquired
by generating indication drive signals by the indication control
devices 204A, 204B, 214A, and 214B, for example, based on servo
control signals that vary in accordance with the teaching
operations in FIG. 3A. In a case where a servo control signal is
used as in this embodiment, when a robot arm is controlled into a
teaching mode, the servo control signal for the arm is controlled
into a servo ON state. With such signal changes, the duty ratio
conversion (or timing conversion) in the indication control devices
204A, 204B, 214A, and 214B is basically not necessary as
illustrated in FIG. 3D. These indication control devices 204A,
204B, 214A, and 214B may be configured to perform a necessary
voltage or current conversion, for example.
[0057] Upon start of a teaching operation in FIG. 3A (step S0), no
teaching operation has been performed yet. Thus, servo control
signals for the robot arms 201 and 211 are servo OFF. As
illustrated in FIGS. 3B and 3C, all indicators 205A, 205B, 215A,
and 215B on the robot arms 201 and 211 have a light-off state.
[0058] Next, an operator performing the teaching operation changes
the robot arm 201 to the teaching mode from the TP 203 (step S1).
In response to the change, the robot control device 202 changes the
servo control signal for the arm to a servo ON state in order to
shift the robot arm 201 to the teaching mode. Thus, the indicator
205A is turned on (light-on state) through the indication control
device 204A.
[0059] Because states of the arms are shared through the LAN 230 as
described above, the teaching mode (such as a state of the servo
control signal) of the robot arm 201 is transmitted to the robot
control device 212 in the robot arm 211 through the LAN 230. The
robot control device 212 supplies a signal based on the servo
control signal of the robot arm 201 to the indication control
device 214B to generate an indication drive signal and thus turn on
(light-on state) indicator 215B. On the other hand, the robot arm
211 here is not in the teaching mode and has a servo OFF state.
Through the reverse control steps to the steps above, the indicator
205B and indicator 215A are controlled into a light-off state (the
same is true below).
[0060] While the teaching operation is being performed with the TP
203 (step S2), the robot control device 202 holds the servo control
signal for the robot arm 201 in a servo ON state through the
indication control device 204A, and the indicator 205A keeps its
light-on state. Because this state is continuously being
transmitted to the robot control device 212, the indicator 215B
keeps its light-on state through the indication control device
214B. Because the robot arm 211 has not been shifted to the
teaching mode yet and has a servo OFF, the indicator 205B and
indicator 215A keep their light-off states through the reverse
control steps to the steps described above.
[0061] When the teaching operation ends and the operator disables
the robot arm 201 from the TP 203 (step S3), the robot control
device 202 changes the servo control signal to a servo OFF state.
In response to this, the indicator 205A is turned off (light-off
state) through the indication control device 204A. Because this
state is continuously transmitted to the robot control device 212,
the indicator 215B is turned off (light-off state) through the
indication control device 214B. The indicators 205B and 215A still
have a light-off state. At the end of the teaching operation (step
S4), all of the indicators hold their light-off state.
[0062] The example has been described in which the robot arm 201 is
controlled into the teaching mode in response to a teaching
operation. However, in a case where the robot arm 211 is controlled
into the teaching mode, indication states at that time may be
illustrated by replacing the reference signs of the indicators in
FIGS. 3B and 3C by each other.
[0063] As described above, according to this embodiment, the
indication devices 205 and 215 each having an indicator configured
to indicate a state of an arm and an indicator configured to
indicate a state of an arm different from the arm are provided near
tips of the juxtaposed robot arms 201 and 211. The indicators 205A,
205B, 215A, and 215B in the indication devices 205 and 215 may be
easily visually recognized especially by a supervisor without
requiring to move his or her line of sight greatly. Therefore, the
supervisor is allowed to easily and simultaneously check not only a
robot arm that he or she is gazing at but also a state, especially
an operability state, of the other juxtaposed arm. Thus, even when
a manipulator switches a robot arm different from a robot arm being
gazed at by a supervisor into the teaching mode through the TPs 203
and 213 without signaling, the supervisor is allowed to immediately
recognize the switching. Therefore, the supervisor may take a
necessary measure such as performing an avoiding behavior and may
concentrate on a job without anxiety. Furthermore, an advantageous
effect is also provided that states of the robot arms may be
checked highly efficiently for smooth job handling.
[0064] According to this embodiment, indication surfaces of the
indication devices 205 and 215 each including an indicator
configured to indicate a state of the specific arm, and an
indicator configured to indicate a state of another arm different
from the specific arm, are provided substantially on all
circumference of a tip part of the robot arm. This structure may be
implemented by ring-shaped indication surfaces of the indication
devices 205 and 215 as illustrated in FIG. 2. This structure allows
a supervisor in particular to easily visually recognize an
indication state of the indication device 205 at any position near
the robot arm 201. The structure does not change even when joints
of the robot arm 201 are controlled into any attitudes and even
when the gripper tip 2011b and finger 2011a are driven to pivot in
any manner. Thus, irrespective of any operation state and job state
of the robot apparatus, an operator is allowed to check the state
of the specific arm, and the state of another arm different from
the specific arm, with high visibility and to smoothly and
efficiently execute teaching operations on the robot apparatus
without anxiety.
[0065] Having described that two robot arms are juxtaposed, the
configuration of the present invention may be implemented also in a
configuration that three or more robot arms are juxtaposed. In that
case, an indication device (such as the indication device 205)
provided at one robot arm may include an indicator which indicates
a state of the arm (the indicator 205A) and indicators which
indicates states of the other arms different from the arm where the
number of the indicators is equal to the number of arms. For
example, the indication device 205 includes the indicator 205A
which indicates a state of the arm and indicators 205B, 205C, 205D
. . . which indicate states of the other arms different from the
arm. Also in this configuration, sharing information regarding
states of the robot arms juxtaposed over a network, for example, as
described above allows an indication device at a tip part of one
specific arm thereof to indicate states of the other arms different
from the specific arm.
[0066] The case has been described above in which two robot arms
201 and 211 are juxtaposed, and the robot control devices 202 and
212 and the TPs 203 and 213 are provided therefor, respectively.
However, the configuration in which the indication devices 205 and
215 having an indicator which indicates a state of one arm, and an
indicator which indicates a state of another arm different from the
arm, are provided in a tip part of a specific arm may be
implemented independently of the arrangement of the robot control
devices and TPs.
[0067] For example, the configuration of the present invention may
also be implemented in a configuration in which one group of robot
control devices and TPs is provided for two robot arms and a
teaching operation is performed on the arms by using a switch for
switching a target of the teaching operation. In this case, the
indication state of one indicator in the indication devices 205 and
215 may be changed in accordance with the selection state of the
target arm of a teaching operation which is controlled by operating
the switch for changing the teaching operation target. In other
words, the indication state of an indicator in the indication
devices 205 and 215 on an arm selected (or unselected) as a
teaching operation target may be caused to flash or change its
indication color. Under this control, an operator is allowed to
grasp, securely and in a stepwise manner, states from a change of
the teaching operation target to a shift of a specific arm into the
teaching mode.
[0068] As illustrated in FIG. 1, in a case where two (or more)
robot arms are juxtaposed and are controlled so as to perform a
specific job process, such a robot arm arrangement unit may
sometimes be called a "cell unit". A unit having a plurality of
such cell units adjacent to each other may sometimes be called a
"station". In the robot apparatus illustrated in FIG. 1, the robot
arms 201 and 211 may be arranged to be configured as one cell unit
as described above and may be taught to perform some type of
assembly or processing steps, for example. On the other hand, one
characteristic of the present invention is that an indication
device (205, 215) has an indicator (205B, 215B . . . ) capable of
indicating a state of a robot arm different from an arm where the
indication device is provided. The indicator (205B, 215B . . . ) is
not always required to indicate a state of a different arm included
in the same arrangement unit such as a cell unit and a station. For
example, the indicator (205B, 215B . . . ) which indicates a state
of a different robot arm may be configured to indicate a state of
an arm included in a different cell unit or station from the one to
which the arm belongs, whether the arms are adjacent or are
separated or not.
[0069] Having described above that each of the indication surfaces
of the indication devices 205 and 215 are provided substantially on
all the circumference of a tip part of a robot arm, they may be
provided on a surface (only) where an operator may visually
recognize most in accordance with, for example, a typical standing
position of the operator. The indication devices 205 and 215, for
example, may be provided over a half circumference of an inner side
(or outer side) of a robot arm from the viewpoint of a manipulator
or a supervisor at a typical standing position.
[0070] In other words, the indication surfaces of the indication
devices 205 and 215 may be provided over at least substantially
half (or more) of the circumference of one side of a tip part of
the robot arms. This achieves a major part of the operation effect
that an operator may easily grasp states of a robot arm, and a
robot arm different from the arm irrespective of the
position/attitude of the robot arm.
[0071] The configuration has been described in which the indication
devices 205 and 215 are provided on the gripper 2011 provided as a
tool for handling an object in a tip part of a robot arm. However,
the tool having the indication devices 205 and 215 is not limited
to such a gripper (hand), but indication devices equivalent to the
indication devices 205 and 215 may be provided on any arbitrary
tool (or end effector) provided in a robot arm. Indication devices
equivalent to the indication devices 205 and 215 may not have to be
provided on a tool or an end effector but may be provided on one
link configured near a tip part of a robot arm, for example.
Second Embodiment
[0072] According to the first embodiment, a servo control signal
may be used for indicating states of robot arms by the indication
devices 205 and 215. However, other signals usable in a robot
apparatus may be used for indication of states of robot arms.
According to a second embodiment, a brake drive signal which drives
a brake for controlling an operation of a joint of a robot arm may
be used to generate an indication drive signal for an indication
device, for example.
[0073] A robot arm may have a brake at a driving axis of a
servomotor for each rotary joint as a drive unit for maintaining
the joint at its position against gravity when a driving power
supply for the servomotor for each rotary joint is shut down. This
type of brake may be a released-on-excitation type brake, for
example. The released-on-excitation type brake operates to brake
and hold an output axis of a servomotor without excitation, and
releases the output axis of the servomotor with excitation.
Normally, the brake is unexcited immediately after a robot
apparatus is powered on, and a driving axis of a servomotor for a
robot arm is therefore braked, and the robot arm is held at its
position/attitude. On the other hand, when the robot arm is shifted
to a teaching mode, each brake is excited and is driven to release
the driving axis of the servomotor for each joint. Thus, states of
the joints may be controlled freely from the servomotors.
[0074] According to this embodiment, a brake control signal for
controlling a brake provided at a joint of the robot arm may be
converted to generate an indication drive signal for an indication
device which indicates a state of a specific arm, and a state of
another arm different from the arm.
[0075] FIGS. 4 and 5 illustrate a configuration of a robot
apparatus according to this embodiment in the same form as that of
FIG. 1. FIGS. 4 and 5 are different only in a wiring scheme applied
in a control system in an indication device using the brake control
signal, and like numbers refer to like parts in FIGS. 4 and 5.
Reference numerals of 300s are used in FIGS. 4 and 5 instead of
200s in FIG. 1, and parts referred by numerals having like lower
two digits are identical or like parts in FIG. 1 and FIGS. 4 and
5.
[0076] A robot apparatus 300 in FIGS. 4 and 5 includes robot arms
301 and 311 which are juxtaposed with each other. Indication
devices 305 and 315 corresponding to an operability indication unit
include indicators 305A, 305B, 315A, and 315B placed at equivalent
positions to those in FIG. 1 in tip parts of the robot arms 301 and
311. The configuration around a gripper having the indication
devices 305 and 315 is substantially the same as the one
illustrated in FIG. 2, and the arrangement structure of the
indicators 305A, 305B, 315A, and 315B may be the same as the
indicators 205A, 205B, 215A, 215B in FIGS. 1 and 2.
[0077] Also in the configuration in FIGS. 4 and 5, the robot arms
301 and 311 have respectively corresponding robot control devices
302 and 312, and TPs 303 and 313 are connected to the corresponding
robot control devices.
[0078] The indication control over the indicators 305A, 305B, 315A,
and 315B in the indication devices 305 and 315 are performed by the
indication control devices 304A, 304B, 314A, and 314B. According to
this embodiment, the indicators 305A and 315A which indicate a
state of an arm having the indication device 305 or 315 are
controlled by indication control devices 304A and 314A.
[0079] Referring to FIGS. 4 and 5, the indication control devices
304A and 314A convert brake control signals for brakes 309K and
319K (one of which provided in one joint of the arms is only
illustrated) to indication drive signals for the indicators 305A
and 315A. The brake control signals are extracted from brakes 309K
and 319K provided in joints close to tips of the robot arms 301 and
311.
[0080] In FIG. 4, the extracted brake control signals are connected
to the indication control devices 304A and 314A provided within the
robot arms 301 and 311. On the other hand, referring to FIG. 5,
brake control signals are derived from brakes provided in joints
close to tips of the robot arms 301 and 311 to outside of the
joints and are connected to the indication control devices 304A and
314A provided outside of the link of the robot arms 301 and 311.
The wires from the indication control devices 304A and 314A to the
indicators 305A and 315A are connected through arms in FIG. 4 and
through outside of the arms in FIG. 5. FIG. 4 and FIG. 5 are
different in the layout of the indication control devices 304A and
314A and the wiring.
[0081] The indication control devices 304B and 314B which perform
indication control over the indicators 305B and 315B in the
indication devices 305 and 315 are provided closely to the robot
control devices 302 and 312 like the indication control devices
204B and 214B in FIG. 1.
[0082] The robot control devices 302 and 312 may be configured in
the same manner as those illustrated in FIG. 8 as described above.
Information regarding states of the robot arms is shared through a
LAN 330 like the first embodiment. For example, states of brake
control signals for the brakes 309K and 319K (FIG. 4) may be shared
through the LAN 330, and the indication control devices 204B and
214B perform indication control over the indicators 305B and 315B
in accordance with the shared state of the brake control signal for
the other arm.
[0083] FIG. 6 is a block diagram illustrating a configuration of an
indication control system applying the brake control signals. The
robot arm 301 in FIG. 6 includes servomotors 307a to 307f for six
joints (six axes: J1 to J6), and operations of the servomotors are
controlled by the robot control device 302 through the driver 306a
to 306f, respectively.
[0084] A brake 308e in FIG. 6 corresponds to the brake 309K in FIG.
4. A brake control signal for the brake 308e is input to the
indication control device 304A and is converted to an indication
drive signal for the indicator 305A. A state of the brake control
signal is shared through the LAN 330 and is input to the indication
control device 304B through the robot control device 302. The robot
arm 311 side, not illustrated in FIG. 6 has the same configuration
as that of the robot arm 301 side.
[0085] FIGS. 7A to 7D illustrate indication control in the
configuration in the same manner as in FIG. 3 according to the
first embodiment.
[0086] FIG. 7A illustrates a flow (step S0 to S5) of control for
performing a manual teaching operation on the robot arm 301. FIG.
7A principally illustrates an operation from the TP 303. Control
over the components of the robot arm 301 in accordance with the
steps (S0 to S5) of the operation is executed by a CPU 501 (FIG. 8)
in the robot control device 302. A control program for the CPU 501
therefor may be prestored in a ROM 502 in FIG. 8, for example.
[0087] FIGS. 7B and 7C illustrate indication states of the
indication devices 305 and 315 on the robot arms 301 and 311
corresponding to the steps (step S0 to S5) in FIG. 7A. In FIGS. 7B
and 7C, light-on and flashing states are illustrated by using a
shaded pattern and so on for the indicators 305A, 305B, 315A, 315B
in the indication devices 305 and 315.
[0088] FIG. 7D illustrates changes of a brake control signal (left
side) and an indication drive signal (right side) in steps S0 to S5
in FIG. 7A. According to this embodiment, the indication states of
the indicators in the indication devices 305 and 315 are acquired
by generating indication drive signals by the indication control
devices 304A, 304B, 314A, and 314B, for example, based on brake
control signals that vary in accordance with the teaching
operations in FIG. 7A.
[0089] According to this embodiment, as illustrated on the left
side of FIG. 7D, when a robot arm is selected as a teaching target
through a TP, a brake control signal is changed to a state in which
the corresponding brake is energized intermittently. After that,
when the robot arm is shifted to the teaching mode, the brake
control signal is shifted to an ON state in which the corresponding
brake is energized. When an arm is selected as a teaching target,
the brake control signal for energizing a brake intermittently has
a duty ratio selected such that all of the brakes are not released,
for example (such as 1 to several tens KHz).
[0090] When a brake control signal exhibits a signal change as
described above, the indication control devices 304A, 304B, 314A,
and 314B perform a duty ratio conversion based on a division ratio,
as illustrated in the left side to the right side of FIG. 7D. As a
result of the conversion, in order to indicate that the arm is
selected as a teaching target, indication drive signals are
acquired which turn the indicators 305A, 305B, 315A, and 315B
ON/OFF at a frequency (such as 1 to several Hz) that allows an
operator to visually recognize. In this manner, a brake drive
signal of pulse width modulated (PWM) waves in a duty ratio region
where a brake is not released is frequency converted and is usable
as an indication drive signal for flashing.
[0091] Referring to FIG. 7A, when a teaching operation starts (step
S0), the brake control signals for the robot arms 301 and 311 have
a duty ratio of 0%. Here, as illustrated in FIGS. 7B and 7C, all
indicators 305A, 305B, 315A, and 315B on the robot arms 301 and 311
are controlled into a light-off state.
[0092] Here, when an operator performing the teaching operation
selects the robot arm 301 as a teaching target through the TP 303
(step S1), the brake control signal has a duty ratio of 10%. Thus,
the brake control signals are converted to indication drive signals
through the indication control devices 304A and 314B, and the
indicator 305A and indicator 315B start to flash (FIG. 7D). At this
point of time, the robot arm 311 is not selected as a teaching
target, and the indicator 305B and indicator 315A are controlled so
as to keep their light-off states. Similarly to the first
embodiment, the indication states of the indicators 305B and 315B
are controlled by using brake control signals shared through the
LAN 330.
[0093] Next, when the operator performs an operation for enabling
the robot arm 301 through the TP 303 (step S2), the robot control
device 302 in response to it changes the brake control signal for
the arm to an energized state with a duty ratio of 100%. Thus,
brakes for the robot arm 301 are changed to a release state. With
the indication drive signals generated by converting the brake
control signals by the indication control device 304A, 314B, the
indicators 305A and 315B change their indication states from
flashing to lighting up (light on state). The indicators 305B and
315A are still controlled so as to keep their light off states.
[0094] While a manipulator is performing a teaching operation on
the arm 301 through the TP 303 (step S3), the brake control signal
is kept with a duty ratio of 100%. The indicators 305A and 315B
keep their light-on state, and the indicators 305B and 315A keep
their light-off state. When the teaching operation ends (steps S4
and S5), the brake control signals return to a duty ratio of 0%,
and the indicators 305A, 305B, 315B, and 315A return to a light-off
state.
[0095] This embodiment also has the same operation effect as that
of the first embodiment regarding a structure having an indication
device including an indicator which indicates a state of a specific
arm and an indicator which indicates a state of another arm
different from the specific arm. In addition to the effect of the
first embodiment, the following operation effect may also be
expected according to this embodiment.
[0096] According to the first embodiment, wiring is required for
transmitting indication drive signals for the indicators 205A and
215A, which indicate states of the arm on which the indication
devices 205 and 215 are provided, to a tip part of the arm through
the inside of the robot arms 201 and 211 and inside of the joints.
On the other hand, according to this embodiment, brake control
signals for controlling brakes in joints of the robot arms 301 and
311 are used to generate indication drive signals for the
indicators 305A and 315A which indicate states of the arms on which
the indication devices 305 and 315 are provided. Thus, this
embodiment may only require wiring of a signal line for brake
control signals, or indication drive signals generated by
converting the brake control signals, from a part near a joint
close to an arm tip part to an arm tip part where the indication
devices 305 and 315 are provided, for example. Therefore, at least
one of signal lines necessary for indication control over the
indication devices 305 and 315 may be shorter than that of the
first embodiment.
[0097] Particularly, because the indicators 305A and 315A in the
indication devices 305 and 315 indicate states of the arms where
they are provided, their indications are highly important.
According to this embodiment, the possibility of broken signal
lines for indicators 305A and 315A whose indication are highly
important may be reduced, greatly improving their reliability.
[0098] As illustrated in FIG. 5, a signal system for indication
control may be provided outside an arm. Referring to FIG. 5, signal
lines for the indicators 305A and 315A include brake control
signals in leads that leave from joints of arms and are connected
to the indication control devices 304A and 314A mounted to one
link, from which indication drive signals are transmitted through
outside of the arms. The signal lines for indication drive signals
transmitted from the indication control devices 304B and 314B to
indicators 305B and 315B also extend outside the arms. An
indication system which indicates states of an arm on which it is
provided, and another arm, may be wired outside of the robot arms
for higher ease of maintenance.
[0099] The configuration in which a signal system for an indication
system, which indicates a state of an arm or another arm, is wired
outside the arm as illustrated in FIG. 5 may relatively easily
address a case where an indication system is added to a robot
apparatus which does not have such an indication system originally.
The configuration in which a signal system for an indication system
is wired outside of arms, as illustrated in FIG. 5, allows a tool
to be detachably mounted to a robot arm, for example, with low
constraint regarding connectors and electrodes for a signal system.
The configuration in FIG. 5 also allows a tool without an
indication system, which indicates a state of an arm where it is
provided or another arm, to be detachably mounted, for example,
with relatively easier commonness in connector and pin arrangement
for a signal system.
[0100] Different variations according to the first embodiment may
also be implemented in this embodiment.
[0101] With the aforementioned distinct configuration according to
the present invention, a first indicator provided in a tip part of
a robot arm is capable of indicating a state of another robot arm
different from the robot arm. Thus, a supervisor concentrating on
an operation on the robot arm is allowed to easily recognize a
state of the other robot arm simultaneously without moving his or
her line of sight. Therefore, according to the present invention,
the supervisor is allowed to take a necessary avoiding behavior by
easily recognizing a shift to a teaching mode of an arm different
from an arm at which he or she is gazing at, for example.
[0102] While the present invention has been described with
reference to embodiments, it is to be understood that the invention
is not limited to the disclosed embodiments. The scope of the
following claims is to be accorded the broadest interpretation so
as to encompass all such modifications and equivalent structures
and functions.
[0103] This application claims the benefit of Japanese Patent
Application No. 2014-119369, filed Jun. 10, 2014, which is hereby
incorporated by reference herein in its entirety.
* * * * *