I Europz‘tlscnes
`Patenlamt
`European
`Paiznt Ot‘i‘iize
`. Office européen
`
`3 dc; brewer:
`
`(19)
`
`<12)
`
`III/IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII
`
`(11)
`
`EP1918 075 A1
`
`EUROPEAN PATENT APPLICATION
`published in accordance with Art. 153(4) EPC
`
`(43) Date of publication:
`07.05.2008 Bulletin 2008/19
`
`(21) Application number: 06768023.1
`
`(22) Date of filing: 10.07.2006
`
`(84) Designated Contracting States:
`DE FR GB
`
`(30) Priority: 01.08.2005 JP 2005222511
`
`(71) Applicant: HONDA MOTOR co., LTD.
`Tokyo 107-8556 (JP)
`
`(72) Inventors:
`- MATSUSHIMA, Kuniaki,
`HONDA R & D CO., LTD.
`Wako-shi, Saitama 3510193 (JP)
`
`(54) MOBILE ROBOT CONTROLLER
`
`(51) Int Cl.:
`825-] 3/00 (2006.01)
`325J 13/00 (2006.01)
`
`325.1 5/0012006-0“
`525.1 19/06 (2006-01)
`
`(86) international application number:
`PCT/JP2006/313661
`
`(87) International publication number:
`WO 20071015351 (08.02.2007 Gazette 2007/06)
`
`- HASEGAWA, Tadaaki,
`HONDA R & D 00., LTD.
`Wako-shi Saitama 3510193 (JP)
`~ KAWAGUCHI, Yuichiro,
`HONDA R & D CO., LTD.
`Wako-shi, Saitama 3510193 (JP)
`
`(74) Representative: Cheyne, John Robert Alexander
`M.
`HASELTINE LAKE
`
`Redclift Quay
`120 Redcliff Street
`
`Bristol BS1 6HU (GB)
`
`
`
`In a mobile robot control system, it is configured
`(57)
`such that the robot (10) generates time-series data se~
`quentially at a predetermined time interval and transmits
`them to the external terminal (90), and the external ter—
`minal receives the transmitted time-series data and adds
`them to the motion command, such that the motion of
`
`the robot is determined based on the generated time~
`
`series data and the timeseries date added to the motion
`
`command, With this, it becomes possible to prevent the
`robot from suddenly starting to move at the time when
`the communication between the external terminal which
`
`is a transmitting source of the motion command and the
`robot has recovered from disconnection, thereby ena—
`bling to avoid making the operator feel unnatural.
`
`10
`
`90
`
`I
`1
`
`RoBOT
`
`
`‘;
`SOCKET
`1
`l COMMUNICATION;
`
`EXTERNAL
`TERMINAL
`
`i OPERATOR 1
`;
`‘
`
`
`
`
`
`;
`;
`1
`i
`
`1 MOTION
`: COMMAND
`I
`
`
`
`RECEIVE RESULT OF
`MOTION COMMAND
`EXECUTION PROCESSING
`
`
`
`
`
`05 sec 1
`'
`05 SEC ‘
`
`f
`
`€_——1j> RECEIVE TIMER DATAtn)
`SEND TIMER DATAtn)
`
`;
`NORMAL
`:
`SEND TIMER DATA(n+I> —r——-—1a RECEIVE TIMER DATA(n+I)
`.
`f """"""""""""I
`
`
`
`
`DAWH“) TO
`k
`0.5 se ———— E
`
`MOTION COMMAND
`SEND TIMER DATA(n+3) a DISCONNECTED ;
`.
`AND SEND IT
`.
`;
`
`SEND TIMER DATAtn+7) ‘31
`RECEIVE MOTION
`F" RECOVERED
`
`OMMAND ‘Hfi—TT;;
`‘
`NORMAL
`l
`SEND RESULT OF MOTIONW19
`COMMAND EXECUTION
`i
`PROCESSING
`I
`
`TIME
`
`_____________________________________________________
`
`Printed by Jouve, 75001 PARIS (FR)
`
`EP1918075A1
`
`

`

`1
`
`EP1 918 075 A1
`
`2
`
`Description
`
`TECHNICAL FIELD
`
`[0001] This invention relates to a mobile robot control
`system. particularly to a system for remote—controlling a
`mobile robot.
`
`BACKGROUND ART
`
`[0002] As a system for remote-controlling a mobile ro~
`bot, a technique taught by Patent Reference 1 can be
`given as an example. in the technique described in Patent
`Reference 1, when the communication between the mo-
`bile robot and an external terminal which is a transmitting
`source of motion command is failed, the mobile robot is
`configured to be controlled to move to a position which
`enables it to communicate with the external terminal
`
`10
`
`15
`
`based on a communication history, such that the mobile
`robot moves only within a predetermined area.
`
`20
`
`Patent Reference 1: Japanese Laid~Open Patent
`Application No. 2002—27367? (paragraph 0007, etc.)
`
`DlSCLOSURE OF THE lNVENTlON
`
`Problems to be solved by the invention
`
`in the case that the communication between
`[0003]
`the external terminal and mobile robot is disconnected,
`motion command that has not been received by the mo—
`bile robot is held in the external terminal. When the com—
`munication has recovered, the held motion command is
`received by the mobile robot so that the robot starts mov~
`ing. However, the motion suddenly starts independently
`of the operator’s intention, thereby causing unnatural
`feeling of the operator.
`[0004] Therefore, an object of this invention is to over~
`come the aforesaid drawback and provide a mobile robot
`control system that prevents a mobile robot from sud—
`denly starting to move at the time when the communica-
`tion between an external terminal which is a transmitting
`source of motion command and the mobile robot has
`
`recovered from disconnection, thereby enabling to avoid
`making the operator feel unnatural. Means for solving
`the problems
`[0005]
`In orderto achieve the object, as recited in claim
`i mentioned below, this invention is configured to have
`a system for controlling a mobile robot having an external
`terminal that generates motion command and transmits
`itto the robot, and controlling means provided atthe robot
`for controlling operation of the robot based on the trans
`mitted motion command, characterized in that: the robot
`is provided with time~series data generating means for
`generating time-series data sequentially at a predeter—
`mined time interval and for transmitting them to the ex~
`ternal terminal; and the external terminal is provided with
`time-series data adding means for receiving the trans-
`
`25
`
`30
`
`4O
`
`45
`
`50
`
`55
`
`mitted time—series data and for adding them to the motion
`command; and the controlling means determines the mo—
`tion of the robot based on the generated time—series data
`and the time-series data added to the motion command.
`
`[0006] As recited in claim 2 mentioned below, this in-
`vention is configured such thatthe controlling means con—
`trols the motion of the robot in accordance with the trans—
`mitted motion command when a difference between a
`
`current one of the time-series data generated by the time
`series data generating means and the time-series data
`added to the motion command is equal to or smaller than
`a predetermined value, and discontinues the motion of
`the robot when the difference is greater than the prede~
`termined value.
`
`[0007] As recited in claim 3 mentioned below, this in—
`vention is configured to have a system for controlling a
`mobile robot having an external terminal that generates
`motion command and transmit it to the robot, and c0n~
`trolling means provided at the robot for controlling oper-
`ation of the robot based on the transmitted motion com—
`
`mand, characterized in that: the robot is provided with
`time~series data generating means for generating time
`series data sequentially at a predetermined time interval
`and for transmitting them to the external terminal; and
`the external terminal is provided with time—series data
`storing means for receiving the transmitted time-series
`data and storing them; communication condition discrim~
`inating means fordiscriminating that communication con-
`dition between the external terminal and the robot is nor—
`mal when the transmitted time-series data are received,
`and for discriminating that the communication condition
`is faulty when the transmitted time—series data are not
`received; motion command storing means for storing the
`motion command by adding the stored transmitted time—
`series data thereto, when the communication condition
`discriminating means discriminates that the communica~
`tion condition is faulty; and transmission determining
`means for determining as to whether the stored motion
`command should be transmitted to the robot based on
`the time-series data added to the stored motion com
`mand and a current one of the received time-series data,
`when the communication condition discriminating means
`discriminates that the communication condition is nor-
`mal.
`
`[0008] As recited in claim 4 mentioned below, this in~
`vention is configured such that the transmission deter-
`mining means determines that the transmission of the
`stored motion command should be discontinued, when
`a difference between the time-series data added to the
`motion command and the current one of the received
`
`time—series data is greater than a predetermined value.
`[0009] As recited in claim 5 mentioned below, this in—
`vention is configured such that the external terminal fur-
`ther includes: motion command deleting means for de~
`leting the motion command whose transmission was dis~
`continued.
`
`[0010] As recited in claim 6 mentioned below, this in—
`vention is configured such that the external terminal fur—
`
`

`

`3
`
`EP1 918 075 A1
`
`4
`
`ther includes: signal generating means for generating a
`communication confirming signal at a predetermined
`second time interval and send it to the robot; and the
`robot includes: second communication condition discrim—
`
`inating means for discriminating that the communication
`condition is normal when the transmitted communication
`
`confirming signal is received, and for discriminating that
`the communication condition is faulty when the transmit—
`ted communication confirming signal is not received; and
`time interval changing means for changing the predeter~
`mined second time interval based on discrimination result
`
`of the second communication condition discriminating
`means.
`
`[0011] As recited in claim 7 mentioned below, this in-
`vention is configured such that the time interval changing
`means shortens the predetermined second time interval
`when the second communication condition discriminat—
`
`ing means discriminates that the communication condi-
`tion is faulty.
`[0012] As recited in claim 8 mentioned below, this in~
`vention is configured such that the robot further includes:
`positional information generating means for generating
`positional information of the robot and transmitting it to
`the external terminal; and the external terminal includes:
`displaying means for receiving the transmitted positional
`information and for displaying it.
`[0013] As recited in claim 9 mentioned below, this in—
`vention is configured such that the robot comprises a
`humanoid robot having a body, two legs connected to
`the body and two arms connected to the body, that moves
`by driving the legs.
`
`Effects of the invention
`
`In the mobile robot control system recited in
`[0014]
`claim 1 mentioned below, since it is configured such that
`the robot generates time-series data sequentially at a
`predetermined time interval and transmits them to the
`external terminal, and the external terminal receives the
`transmitted time~series data and adds them to the motion
`command, such thatthe motion ofthe robot is determined
`based on the generated time-series data and the time
`series data added to the motion command, it becomes
`possible to prevent the robot from suddenly starting to
`move at the time when the communication between the
`
`external terminal which is a transmitting source of the
`motion command and the robot has recovered from dis~
`
`connection, thereby enabling to avoid making the oper~
`ator feel unnatural.
`
`in the mobile robot control system recited in
`[0015]
`claim 2 mentioned below, since it is configured such that
`the motion of the robot is controlled in accordance with
`the transmitted motion command when a difference,
`more specifically a difference in time between a current
`one of the time—series data and the time-series data add—
`
`ed to the motion command is equal to or smaller than a
`predetermined value, and the motion of the robot is dis—
`continued when the difference is greater than the prede-
`
`termined value, it becomes possible to prevent the robot
`from suddenly starting to move at the time when the com—
`munication between the external terminal and the robot
`
`has recovered from disconnection, thereby enabling to
`avoid making the operator feel unnatural.
`[0016]
`in the mobile robot control system recited in
`claim 3 mentioned below, since it is configured such that
`the robot generates time~series data sequentially at a
`predetermined time interval and transmits them to the
`external terminal, and the external terminal receives the
`transmitted time—series data to store them, discriminates
`that communication condition between the external ter-
`minal and the robot is normal when the transmitted time
`
`series data are received, whereas discriminating that the
`communication condition is faulty when the transmitted
`time-series data are not received, stores the motion com—
`mand by adding the stored transmitted time—series data
`thereto, when the communication condition is discrimi~
`nated to be faulty, and determines as to whether the
`stored motion command should be transmitted to the ro-
`bot based on the time-series data added to the stored
`motion command and a current one of the received time
`series data, when the communication condition is dis
`criminated to be normal, it becomes possible to prevent
`the robot from suddenly starting to move at the time when
`the communication between the external terminal which
`
`is a transmitting source of the motion command and the
`robot has recovered from disconnection, thereby ena-
`bling to avoid making the operator feel unnatural.
`[0017]
`in the mobile robot control system recited in
`claim 4 mentioned below, since it is configured such that
`the transmission of the stored motion command is dis-
`
`continued, when a difference, more specifically a differ—
`ence in time between the time~series data added to the
`motion command and the current one of the received
`
`timevseries data is greater than a predetermined value,
`it becomes possible to prevent the robot from suddenly
`starting to move at the time when the communication
`between the external terminal and the robot has recov—
`
`ered from disconnection, thereby enabling to avoid mak-
`ing the operator feel unnatural.
`[0018]
`In the mobile robot control system recited in
`claim 5 mentioned below, since it is configured such that
`the motion command whose transmission was discon—
`tinued is deleted,
`in addition to the effects mentioned
`above, it becomes possible to prevent a storage area of
`the motion command storage from being unnecessarily
`consumed.
`
`in the mobile robot control system recited in
`[0019]
`claim 6 mentioned below. since it is configured such that
`the external terminal generates a communication con-
`firming signal at a predetermined second time interval
`and send it to the robot, and the robot discriminates that
`the communication condition is normal when the trans
`
`is received,
`mitted communication confirming signal
`while discriminating that the communication condition is
`faulty when the transmitted communication confirming
`signal is not received, and changes the predetermined
`
`10
`
`15
`
`20
`
`25
`
`30
`
`4O
`
`45
`
`50
`
`55
`
`

`

`5
`
`EP1 918 075 A1
`
`6
`
`second time interval based on discrimination result, in
`addition to the effects mentioned above, it becomes pos~
`sible to immediately determine as to whether the motion
`command should be transmitted to the robot when the
`communication between the external terminal and the
`robot has recovered from disconnection.
`
`In the mobile robot control system recited in
`[0020]
`claim 7 mentioned below, since it is configured such the
`predetermined second time interval is shortened when
`the communication condition is discriminated to be faulty,
`it becomes possible, as same as claim 6, to immediately
`determine as to whether the motion command should be
`transmitted to the robot when the communication be—
`tween the external terminal and the robot has recovered
`from disconnection.
`
`In the mobile robot control system recited in
`[0021]
`claim 8 mentioned below, since it is configured such that
`the robot generates positional information of the robot
`and transmits it to the external terminal, and the external
`terminal receives the transmitted positional information
`and displays it, in addition to the effects, even when the
`operator cannot visually check the robot, helshe can op—
`erate the robot.
`
`In the mobile robot control system recited in
`[0022]
`claim 9 mentioned below, since it is configured such that
`the robot comprises a humanoid robot having a body,
`two legs connected to the body and two arms connected
`to the body, that moves by driving the legs, it becomes
`possible forthe humanoid robot to obtain the effects men~
`tioned above.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`[0023]
`
`FIG. 1 is a front view of a robot to which a mobile
`
`robot control system according to a first embodiment
`of the invention is mounted.
`FIG. 2 is a side view of the robot shown in FIG. 1.
`
`FIG. 3 is an explanatory view showing a skeletonized
`view of the robot shown in FIG. 1.
`
`FIG. 4 is a block diagram functionally showing the
`structures of the robot and an external terminal
`
`shown in FIG. 2, and the operation thereof.
`FIG. 5 is a flowchart showing sending and receiving
`processing of timer data and the like, executed be-
`tween the robot and external terminal shown in FIG.
`2.
`
`FIG. 6 is a flowchart showing motion control process—
`ing of the robot executed by the robot and external
`terminal shown in FIG. 2.
`
`FIG. 7 is a time chartfor expressing the sending and
`receiving processing of motion command and the
`timer data, executed between the robot and external
`terminal shown in FIG. 2.
`
`FIG. 8 is a block diagram similarto FIG. 4 but func~
`tionally showing the structure of a mobile robot con~
`trol system according to a second embodiment of
`
`the invention and the operation thereof.
`FIG. 9 is a flowchart showing sending and receiving
`processing of timer data and communication con-
`firming signal, executed between a robot and exter~
`naI terminal shown in FIG. 8.
`
`FIG. 10 is a flowchart showing the sending process—
`ing of motion command executed by the external ter—
`minal shown in FIG. 8.
`
`FIG. 11 is a time chart for expressing the sending
`and receiving processing of the motion command,
`timer data and communication confirming signal, ex—
`ecuted between the robot and external terminal
`shown in FIG. 8.
`
`BEST MODES OF CARRYING OUT THE INVENTION
`
`Preferred embodiments for carrying out a mo-
`[0024]
`bile robot control system according to the present inven~
`tion will now be explained with reference to the attached
`drawings.
`
`First embodiment
`
`FIG. 1 is afrcnt view of a robot to which a mobile
`[0025]
`robot control system according to a first embodiment of
`the invention is mounted and FIG. 2 is a side view of the
`robot shown in FIG. 1.
`It should be noted that,
`in the
`embodiments a humanoid legged mobile robot having a
`body and two legs and two arms connected thereto,
`which moves by driving the two legs (walks on two legs),
`is taken as an example ofthe mobile robot.
`[0026] As shown in FIG. 1, the mobile robot (hereinat~
`ter referred to as "robot") to is equipped with right and
`left legs 12R, 12L (R and L indicating the right and left
`sides; hereinafterthe same). The legs 12R, 12L are con—
`nected to the lower end of a body 14. A head 16 is con-
`nected to the upper end of the body 14 and right and left
`arms 20R, 20L are connected to opposite sides of the
`body 14. Hands 22R, 22L are attached to the distal ends
`of the right and left arms 20R, 20L.
`[0027] As shown in FIG 2, a housing unit24 is mounted
`on the back of the body 14 for accommodating an elec-
`tronic control unit (hereinafter referred to as "ECU") 26,
`a battery (not shown) and the like.
`[0028]
`FIG. 3 is an explanatory view showing a skele~
`tonized view ofthe robot 10 shown in FIG. 1. The internal
`
`structures of the robot to will be explained with reference
`to FIG. 3, with primary focus on the joints.
`[0029] The right and left legs 12R, t2L are equipped
`with thigh links 30R, 30L, shank links 32R, 32L and feet
`34R, 34L. The thigh links 30R, 30L are connected to the
`body 14 through hip (crotch)ioints. The body 14 is rep—
`resented in FIG. 3 simply by a body link 36. The thigh
`links 30R, 30L and shank links 32R, 32L are intercon~
`nected by knee joints, and the shank links 32R, 32L and
`feet 34R, 34L are interconnected by ankle joints.
`[0030] The hip joints are constituted of rotary shafts
`40R, 40L rotating about the Z axis (yaw axis; specifically
`
`10
`
`15
`
`20
`
`25
`
`30
`
`4O
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`45
`
`50
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`55
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`

`

`7
`
`EP1 918 075 A1
`
`8
`
`in the height direction of the robot 10), rotary shafts 42R,
`42L rotating about the Y axis (pitch axis; specifically in
`the lateral direction of the robot 10), and rotary shafts
`44R, 44L rotating about the X axis (roll axis; specifically
`in the back-and-forth direction of the robot 10). The hip
`joints are each provided with 3 degrees of freedom.
`[0031] The knee joints are constituted of rotary shafts
`46R, 46L rotating about the Y axis and each provided
`with 1 degree of freedom. The anklejoints are constituted
`of rotary shafts 48R, 48L rotating about the Y axis and
`rotary shafts 50R, 50L rotating about the X axis and each
`provided with 2 degrees of freedom. Thus the right and
`left legs 12R, 12L are each provided with 6 rotary shafts
`(6 degrees of freedom) constituting the three joints, i.e.,
`the whole legs are provided with a total of 1 2 rotary shafts.
`[0032] The legs 12R, 12L are driven by actuators (not
`shown). Specifically, the actuators driving the legs 12R,
`12L comprise 12 electric motors disposed at appropriate
`positions in the body 14 and legs 12R, 12L and drive the
`12 rotary shafts individually or separately. Owing to the
`foregoing configuration, the legs 12R, 12L can be impart-
`ed with desired movements by controlling the operation
`of the motors to drive the rotary shafts to appropriate
`angles.
`[0033] The right and left arms 20R, 20L are equipped
`with upper arm links 52R, 52L, forearm links 54R, 54L
`and the hands 22R, 22L. The upper arm links 52R, 52L
`are connected through shoulder joints to the body 14.
`The upper arm links 52R, 52L and forearm links 54R,
`54L are interconnected by elbow joints and the forearm
`links 54R, 54L and hands 22R, 22L are interconnected
`by wrist joints.
`[0034] The shoulder joints are constituted of rotary
`shafts 56R, 56L rotating about the Y axis. rotary shafts
`58R, 58L rotating about the X axis and rotary shafts 60R,
`60L rotating about the Z axis and each provided with 3
`degrees of freedom. The elbow joints are constituted of
`rotary shafts 62R, 62L rotating about the Y axis and each
`provided with t degree of freedom. The wrist joints are
`constituted of rotary shafts 64R, 64L rotating about the
`Z axis, rotary shafts 66R, 66L rotating about the Y axis
`and rotary shafts 68R. 68L rotating about the X axis and
`each provided with 3 degrees of freedom. Thus the right
`and left arms 20R, 20L are each provided with 7 rotary
`shafts (7 degrees of freedom) constituting the three
`joints, i.e., the whole arms are provided with a total of 14
`rotary shafts.
`[0035]
`Similar to the legs 12R, 12L, the arms 20R, 20L
`are also driven by actuators (not shown). Specifically,
`the actuators driving the arms 20R, 20L comprise 14 elec—
`tric motors disposed at appropriate positions in the body
`14 and arms 20R, 20L and drive the 14 rotary shafts
`individually or separately. Owing to the foregoing config-
`uration, the arms 20R, 20L can be imparted with desired
`movements by controlling the operation of the motors to
`drive the rotary shafts to appropriate angles.
`[0036] The each hand 22R(22L) is equipped with five
`fingers 7OR(70L). Each of the fingers 70R, 70L is freely
`
`driven by a drive mechanism (having actuators; not
`shown) and can be operated to grasp an object, for in-
`stance, in cooperation with the movement of arms 20R,
`20L.
`
`[0037] The head 16 is connected to the body 14
`through a neck joint. The neck joint is constituted of a
`rotary shaft 72 rotating about the Z axis and a rotary shaft
`74 rotating about the Y axis and is provided with 2 de-
`grees of freedom. The rotary shafts 72 and 74 are also
`driven by actuators (electric motors; not shown) individ—
`ually or separately.
`[0038]
`Six—axis force sensors 76R, 76L are attached
`to the right and left legs 12R. 12L (specifically, between
`the feet 34R, 34L and anklej’oints), respectively. The six~
`axis force sensors 76R, 76L produce outputs or signals
`indicative of the floor reaction force components Fx, Fy
`and F2 of three directions and the moment components
`Mx. My and M2 of three directions acting on the legs 12R,
`12L (specifically, acting on the robot 10 through the legs
`12R, 12L) from the surface of contact.
`[0039]
`Similar six—axis force sensors 80R, 80L are at-
`tached to the right and left arms 20R, 20L (specifically,
`between the hands 22R, 22L and wrist joints), respec-
`tively. The six-axis force sensors 80R, 80L produce out—
`puts or signals indicative of the external force compo—
`nents Fx, Fy and F2 of three directions and the moment
`components Mx, My and M2 of three directions acting on
`the arms 20R, 20L (specifically, acting on the robot 10
`through the arms 20R, 20L).
`[0040] An inclination sensor 82 is installed on the body
`14 and produces an output or signal representing at least
`one of the inclination (tilt angle) of the body 14 relative
`to the vertical axis and the angular velocity thereof, i.e.,
`representing at least one quantity of state such as the
`inclination (posture) of the body 14. The interior of the
`head 16 is mounted therein with right and left CCD cam~
`eras 84R, 84L respective of which takes an image of the
`surrounding of the robot 10 and simultaneously output
`the taken images.
`[0041] The outputs from the sensors and the cameras
`are sent to the ECU 26 shown in HS. 2. The ECU 26
`
`comprises a microcomputer having a CPU, an input/out-
`put circuit, a ROM, a RAM and the like (none of which
`are shown), and is freely communicated with an external
`terminal 90.
`
`FIG. 4 is a block diagram functionally showing
`[0042]
`the structure of the robot 10 and external terminal 90,
`and the operation thereof.
`[0043] As shown in FIG. 4, the robot to having the
`sensors and cameras mentioned in the foregoing is fur~
`ther equipped with rotation angle sensors 92, a gyro sen-
`sor 94 and a GPS receiver 96. The rotation angle sensors
`92 are constituted of a number of rotary encoders that
`produce outputs or signals indicative of the rotation an-
`gles of
`the aforesaid rotary shafts (i.e., operation
`amounts of the motors). The gyro sensor 94 produces
`an output or signal indicative of the moving distance and
`direction of the robot 10. The GPS receiver 96 receives
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`EP1 918 075 A1
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`radio signals transmitted from satellites to acquire infor~
`mation about the position (latitude and longitude) of the
`robot 10.
`
`[0044] The ECU 26 is equipped with a surrounding in-
`formation generator 100, self—position information gen-
`erator 102, self—information generator 104, motion con~
`troller 106 and timerdata generator 108. The surrounding
`information generator 100 is inputted with the image ac—
`quired by the CCD cameras 84R, 84L to produce infor—
`mation about the surroundings of the robot 10. Specifi~
`cally, it produces three-dimensional distance data based
`on the brightness of the acquired image taken by the
`CCD cameras 84R. 84L, extracts clusters representing
`an obstacle(s) from the distance data by using, for in-
`stance,
`the histogram processing. and extracts an
`amount of characteristics such as an average position,
`size and the like of the obstacles in the real space from
`the extracted clusters to generate an obstacle map of the
`surroundings of the robot 10. Since the technique related
`to the obstacle detection is described in detail in Japa~
`nese Laid—Open Patent Application Nos. 2001—2472934
`and 2002—286416 proposed earlier by the applicant. the
`further explanation is omitted.
`[0045] The self-position information generator 102
`produces current positional information of the robot 10
`based on positional information inputted from the GPS
`receiver 96. When the GPS receiver 96 is not able to
`
`receive radio wave transmitted from satellites, it produc«
`esthe current positional information based on the moving
`direction and distance of the robot 1O detected by the
`gyro sensor 94. The current positional information may
`be produced based on the amount of motion of the robot
`10 detected by the rotation angle sensors 92 or control
`values (explained later) of the motors sent from the mo~
`tion controller 106.
`
`[0046] The self-information generator 104 produces
`self—information such as a self-position relative to an ob-
`stacle based on the surrounding information (obstacle
`map) of the robot 10 produced by the surrounding infor-
`mation generator 100 and the current positional informa—
`tion of the robot 10 produced by the self-position infor—
`mation generator 102. The self-information produced by
`the self-information generator 104 is forwarded to the
`motion controller 106.
`
`[0047] The timer data generator 108 generates timer
`data (time—series data) sequentially at a predetermined
`time interval, i.e., 0.5 sec. The predetermined time inter~
`val will be hereinafter called the "timer data generating
`interval."
`
`[0048] The timer data is data indicative of a time point
`(time when the timer data is generated) and can be ex-
`pressed using an elapsed period from a certain time (e.g.,
`0.5 sec, 1.0 sec, 1.5 sec, ...) or using a variable that is
`updated based on a given rule at the timer data gener—
`ating interval (e.g., 1, 2, 3, ...). in this embodiment, when
`timer data indicative of a certain time is defined as "timer
`
`terval from the time specified by the timer data (n), is
`defined as "timer data (n+m)." Specifically, timer data
`indicative of a time point 0.5 sec after a certain time point
`specified by timer data (n) is expressed with "timer data
`(n+1 )“ and timer data indicative ofa time point 1 sec after
`the same is with "timer data (n+2)." The timer data gen—
`erated by the timer data generator 108 is sent to the ex-
`ternal terminal 90 through a data transmitter 110 dis~
`posed in the robot 10.
`[0049] The external terminal 90 comprising a personal
`computer is located separately from the robot 10. The
`external terminal 90 is a transmitting source of motion
`command for the robot 10 and equipped with an input
`device (a keyboard or a mouse) 112 provided to be freely
`operable by the operator, motion command generator
`114, data storage 1 16, data transmitter1 18, data receiver
`120 and display 122.
`[0050] The data transmitter 118 and data receiver 120
`can be freely communicated by radio with a data receiver
`124 and the data transmitter 110 in the robot 10, respec—
`tively. To be specific, the radio communication is the
`socket communication utilizing the TCP (Transmission
`Control Protocol).
`[0051] The timer data sent from the data transmitter
`110 of the robot to is received by the data receiver 120
`of the external terminal 90 and inputted to the data stor~
`age 116. The data storage 116 stores (memorizes) the
`latest value of the inputted timer data (the most recent
`value of the timer data received by the external terminal
`90).
`[0052] The motion command generator 114 of the ex~
`ternal terminal 90 generates motion commands for the
`robot 10 based on the operation of the input device 112
`by the operator. The motion command generated by the
`motion command generator 114 is added with timer data
`stored (memorized) in the data storage 116. The motion
`command and timer data added thereto are forwarded
`from the data transmitter 118 to the robot 10.
`
`[0053] The motion command and timer data sent from
`the data transmitter 1 18 are received by the data receiver
`124 of the robot 10 and inputted to the motion controller
`106.
`
`[0054] Based on timer data generated bythetimer data
`generator 108 and anothertimer date added to the motion
`command, the motion controller 106 determines motion
`of the robot 10. Specifically, when a difference between
`the latest (current) timer data and anothertimer data add—
`ed to the motion command, more precisely, a difference
`between a time indicated by the latest timer data and a
`time indicated by the timerdata added to the motion com
`mand (i.e., a difference in terms of time), is equal to or
`less than a predetermined value. the motion controller
`106 controls motion of the robot 10 in accordance with
`the motion command sent from the external terminal 90.
`
`The robot 10 is operated by calculating control values of
`the motors mounted on the robot 10 based on the motion
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`data (n)," another timer data indicative of a time point
`after elapse of m times of the timer data generating in—
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`command, self—information and outputs of the sensors
`and outputting the calculated control values to the motors
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`to control the operations thereof. Although a technique
`described in, for example, Japanese Laid-Open Patent
`Application No. Hei 10(1998)~277969 earlier proposed
`by the applicant is applied as a locomotion control of the
`robot 10, it is not directly related to the gist of this inven-
`tion, so will not be explained here.
`[0055] On the other hand, when a difference between
`the latest timer data and the timer data added to the mo—
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`tion command exceeds the predetermined value, the op—
`eration ofthe robot 10 is discontinued. Specifically, in the
`case that it is the middle of motion of the robot 10, the
`motion is disconti