Robot control system provided with function of changing criterion for communication quality in accordance with distance between machine and portable wireless operation panel

{
  "publication_number": "US9902060B2",
  "country": "US",
  "kind": "B2",
  "title": "Robot control system provided with function of changing criterion for communication quality in accordance with distance between machine and portable wireless operation panel",
  "abstract": "A robot control system of the present invention includes: a control device for controlling a machine; a portable wireless operation panel that can perform wireless communication with the control device to control the machine; a distance measuring unit that measures the distance between the machine and the portable wireless operation panel; a communication monitoring unit that monitors the communication quality of wireless communication between the control device and the portable wireless operation panel; a warning generator that emits a warning to the operator or stops the machine when the communication quality becomes lower than a predetermined criterion; and, a criterion changing unit that changes the predetermined criterion in accordance with the distance between the machine and the portable wireless operation panel.",
  "claims": [
    "1. A robot control system comprising: a control device for controlling a machine; a portable wireless operation panel for performing wireless communication with the control device to control the machine; a distance measuring unit for measuring the distance between the machine and the portable wireless operation panel; a communication monitoring unit for monitoring the communication quality of wireless communication between the control device and the portable wireless operation panel; a warning generator for emitting a warning to the operator or stopping the machine when the communication quality becomes lower than a predetermined criterion; and a criterion changing unit for changing the predetermined criterion in accordance with the distance between the machine and the portable wireless operation panel.",
    "2. The robot control system according to claim 1, wherein the communication quality is monitored by measuring an exchanging interval of live data for confirming establishment of the wireless communication.",
    "3. The robot control system according to claim 1, wherein the communication quality is monitored by measuring an exchanging interval of safety signals that are exchanged between the control device and the portable wireless operation panel to indicate whether or not the machine should be stopped.",
    "4. The robot control system according to claim 1, wherein the communication quality is monitored by measuring the interval at which data with an error-detecting code or an error-correcting code that is exchanged between the control device and the portable wireless operation panel is exchanged in an error free condition or by measuring the frequency of errors.",
    "5. The robot control system according to claim 1, wherein the communication quality is monitored by measuring radio wave intensity of the wireless communication.",
    "6. The robot control system according to claim 1, wherein the distance between the machine and the portable wireless operation panel is measured by a sensor including, at least, one of a laser sensor, a pressure sensor, an infrared sensor and a light curtain, arranged near the machine.",
    "7. The robot control system according to claim 1, wherein the distance between the machine and the portable wireless operation panel is measured by analyzing an image of surroundings of the machine taken by a fixed camera."
  ],
  "description_excerpt": "1. Field of the Invention\n\nThe present invention relates to a robot control system, in particular, relating to a robot control system provided with a function of changing the criterion for communication quality in accordance with the distance between a machine and a portable wireless operation panel.\n\n2. Description of the Related Art\n\nA portable operation panel for teaching a robot is required to satisfy the standard (ISO 10218-1) that the operation panel can output signals to perform an emergency stop of the robot so as to be able to promptly stop the robot in an emergency. When a portable operation panel is used based on wireless communication, there is a risk that the robot cannot be stopped promptly if the quality of the wireless communication is low, and hence is hazardous. For this reason, it has been a practice that the robot is stopped when the quality of wireless communication becomes lower than a certain level to thereby ensure safety.\n\nHowever, the communication quality of wireless communication may be degraded by environmental influences such as the existence of obstacles, other wireless communications and the like, hence it is inconvenient if the criterion for stopping the robot due to the communication quality is strict. On the other hand, if the criterion is loosened, there is a risk that a long time is taken to correctly transmit an emergency stop signal when teachings and other hazardous tasks are executed, causing safety problems.\n\nAs a conventional robot control system, there has been a known system which ensures safety by recognizing the position of the operator (e.g., Japanese Patent No. 5492438).",
  "cpc": [
    "B25J 9/1602",
    "B25J 13/006",
    "B25J 13/08",
    "B25J 13/088",
    "G01S 11/06",
    "G01S 5/16",
    "G05B 19/414",
    "G05B 2219/31081",
    "H04B 17/309",
    "H04W 76/045",
    "H04W 76/25"
  ],
  "ipc": [
    "B25J 13/00",
    "B25J 9/16",
    "G01S 11/06",
    "G01S 5/16",
    "G05B 19/414",
    "H04B 17/309"
  ],
  "assignees": [
    "Fanuc Corp"
  ],
  "inventors": [
    "Ryoutarou Inaba"
  ],
  "filing_date": "2016-03-11",
  "publication_date": "2018-02-27",
  "grant_date": "2018-02-27",
  "priority_date": "2015-03-19",
  "application_number": "US-201615067180-A",
  "family_id": "56853375",
  "cited_by_count": 3,
  "citations": [
    "JPH02262988A",
    "JP2004314255A",
    "JP2005196441A",
    "US20050244260A1",
    "US8032253B2",
    "US20090030550A1",
    "WO2006103838A1",
    "US20070063834A1",
    "US20090204261A1",
    "JP2007233817A",
    "JP5492438B2",
    "JP2012223831A",
    "WO2013105264A1",
    "US9278447B2",
    "US20150197010A1"
  ]
}