Robot coordinated control method and system

{
  "publication_number": "US7330777B2",
  "country": "US",
  "kind": "B2",
  "title": "Robot coordinated control method and system",
  "abstract": "A reference signal is transmitted from one of a plurality of robot control devices connected by communication connecting device to the other robot control device. The timing of generation of an operation basic period signal in each of the other robot control devices is synchronized with the timing of generation of an operation basic period signal in the one of the plurality of robot control devices, based on a time interval from generation of the operation basic period signal until transmission of the reference signal in the one of the plurality of robot control devices, a time interval from generation of the operation basic period signal until reception of the reference signal in each of the other robot control devices, and a communication delay time required for communication between the one of the plurality of robot control devices and each of the other robot control devices.",
  "claims": [
    "1. A robot coordinated control method comprising steps of communicating among a plurality of robot control devices each generating an operation basic period signal at a predetermined period and controlling at least one robot synchronized with the operation basic period signal, and making said robots controlled by said plurality of robot control devices coordinately operate, wherein said robot coordinated control method further comprises steps of: transmitting a reference signal from one of said plurality of robot control devices to the other robot control devices; and synchronizing the timing of generation of the operation basic period signal in each of said other robot control devices with the timing of generation of the operation basic period signal in said one of said plurality of robot control devices, based on a time interval from generation of the operation basic period signal until transmission of the reference signal in said one of said plurality of robot control devices, a time interval from generation of the operation basic period signal in each of said other robot control devices until reception of the reference signal by each of said other robot control devices, and a communication delay time required for communication between said one of said plurality of robot control devices and each of said other robot control devices.",
    "2. The robot coordinated control method according to claim 1, further comprising a step of obtaining the communication delay time required for communications between said one of said plurality of robot control devices and each of said other robot control devices by making each of said other robot control devices receive the reference signal transmitted from said one of said plurality of robot control devices and then making said one of said plurality of robot control devices receive a response signal transmitted from each of said other robot control devices.",
    "3. The robot coordinated control method according to claim 2, further comprising steps of; making each of said other robot control devices receive the reference signal from said one of said plurality of robot control devices and then, after a predetermined delay time elapses, transmit the response signal to said one of said plurality of robot control devices; and using half of the time interval comprised of the time interval from when said one of said plurality of robot control devices transmits the reference signal to when it receives the response signal from each of said other robot control devices minus said predetermined delay time as the communication delay time.",
    "4. The robot coordinated control method according to claim 1, further comprising a step of adjusting the timing of generation of the operation basic period signals in each of said other robot control devices so that the time interval from generation of the operation basic period signal in each of said other robot control devices until reception of the reference signal by each of said other robot control devices is equal to the time interval comprised of the time interval from generation of the operation basic period signal until transmission of the reference signal in said one of said plurality of robot control devices plus the communication delay time.",
    "5. The robot coordinated control method according to claim 1, wherein said one of said plurality of robot control devices is a master control device, and said other robot control devices are slave control devices.",
    "6. A robot coordinated control system comprising a plurality of robot control devices each generating an operation basic period signal at a predetermined period and controlling the operation of at least one robot synchronized with the operation basic period signal, and a communication connecting means for connecting said plurality of robot control devices to each other, said plurality of robot control devices communicating with each other through said communication connecting means to coordinately operate said robots controlled by said plurality of robot control devices, wherein each of said plurality of robot control devices comprises a reference signal transmitting means for transmitting a reference signal through said communication connecting means to the other robot control devices, a reference signal receiving means for receiving the reference signals transmitted from said other robot control devices through said communication connecting means, and a timer means; the reference signal transmitted from said reference signal transmitting means of said one of said plurality of robot control devices is received by said reference signal receiving means of said other robot control devices; the timing of generation of the operation basic period signal in each of said other robot control devices is synchronized with the timing of generation of the operation basic period signal in said one of said plurality of robot control devices, based on a time interval from generation of the operation basic period signal until transmission of the reference signal in said one of said plurality of robot control devices measured by said timer means of said one of said plurality of robot control devices, a time interval from generation of the operation basic period signal in each of said other robot control devices until reception of the reference signal by each of said other robot control devices measured by said timer means of each of said other robot control devices; and a communication delay time required for communication between said one of said plurality of robot control devices and each of said other robot control devices.",
    "7. The robot coordinated control system according to claim 6, wherein said other robot control devices adjust their own timings of generation of the operation basic period signal so that the time interval from generation of the operation basic period signal in each of said other robot control devices until reception of said reference signal by each of said other robot control devices is equal to the time interval comprised of the time interval from generation of the operation basic period signal until transmission of the reference signal in said one of said plurality of robot control devices plus the communication delay time."
  ],
  "description_excerpt": "1. Field of the Invention The present invention relates to a robot coordinated control method and system for coordinating operation of a plurality of robots. 2. Description of the Related Art When each of a plurality of robot control devices controls one or more robots and the plurality of robots controlled by these plurality of robot control devices jointly perform one job, there may be a need to coordinate the operation of the plurality of robots. In this case, generally, one of the plurality of robots is made the master robot, while the other robots are made slave robots. Further, the plurality of robot control devices are connected to each other using the Ethernet® or other communication connecting means, the current position of the master robot is transmitted from the robot control device of the master robot to the robot control devices of the slave robots through the communication connecting means, and the slave robots are operated based on the transmitted position data of the master robot.\n\nThe robot control cycle is set so as to begin synchronized to an operation basic period signal generated at a constant period inside the robot control device. However, each robot control device independently generates an operation basic period signal, and therefore a deviation in the timing of generation can occur between the different robot control devices. This deviation in the timings of generation of the operation basic period signals is not a problem in cases when one robot control device controls a plurality of robots for coordinated operation.",
  "cpc": [
    "H04J 3/0667",
    "B25J 9/1682"
  ],
  "ipc": [
    "B25J 9/10",
    "G05B 19/04",
    "G05B 19/18",
    "G05B 19/418"
  ],
  "assignees": [
    "FANUC LTD"
  ],
  "inventors": [
    "HASHIMOTO YOSHIKI",
    "OHYA TOMOKI"
  ],
  "filing_date": "2006-08-25",
  "publication_date": "2008-02-12",
  "grant_date": "2008-02-12",
  "priority_date": "2005-08-26",
  "application_number": "US-46736406-A",
  "family_id": "37529434",
  "citations": [
    "JP2003145462A",
    "US6374155B1",
    "US6484083B1",
    "US6496755B2",
    "US6836701B2",
    "US7054716B2"
  ]
}