Fault diagnosis device for robot and robot system

{
  "publication_number": "US11582850B2",
  "country": "US",
  "kind": "B2",
  "title": "Fault diagnosis device for robot and robot system",
  "abstract": "A fault diagnosis device is configured to diagnose a fault in a light emitting unit that emits light of a color according to an operating state of a robot by individually energizing and lighting a plurality of types of LEDs of different emission colors. The fault diagnosis device includes an energization control unit that controls energization of the LEDs, a voltage detection unit that detects a diagnostic voltage that varies depending on a terminal voltage of the LEDs, and a fault detection unit that detects a fault in the light emitting unit based on a control state of energization by the energization control unit and a detected value of the diagnostic voltage by the voltage detection unit.",
  "claims": [
    "1. A fault diagnosis device provided in an industrial robot, comprising: a light emitting unit provided in the robot, the light emitting unit including (i) a plurality of types of light emitting diodes that emit different emission colors when the light emitting diodes are individually energized, and (ii) a plurality of switches that selectively switch on and off energization of the light emitting diodes, the different emission colors showing a robot state of the robot including operating states of the robot and a fault caused in the light emitting unit; an energization control unit configured to selectively control on and off states of the switches so that the energization of the light emitting diodes are selectively controlled; a voltage detection unit configured to detect, as a diagnostic voltage, a unique terminal voltage of the light emitting diodes when the energization control unit controls the switches, the unique terminal voltage being different depending on whether the robot is in the operating states or whether the fault is caused in the light emitting unit; and a fault detection unit configured to detect the fault caused in the light emitting unit based on a state of the energization controlled by the energization control unit and a value of the diagnostic voltage detected by the voltage detection unit.",
    "2. The fault diagnosis device according to claim 1, wherein, when the operating state of the robot shows an operating state in which only one of the light emitting diodes in the light emitting unit is energized, the energization control unit is configured to energize one of remaining light emitting diodes other than the one of the light emitting diodes, and the fault detection unit is configured to detect the fault in the light emitting unit based on the state of the energization controlled by the energization control unit and the value of the diagnostic voltage detected in a period during which the energization control unit energizes the one of the remaining light emitting diodes.",
    "3. The fault diagnosis device according to claim 1, wherein, when the operating state of the robot shows an operating state in which only one of the light emitting diodes in the light emitting unit is energized, the energization control unit is configured to energize a plurality of light emitting diodes among remaining light emitting diodes other than the one of the light emitting diodes, and the fault detection unit is configured to detect the fault in the light emitting unit based on the state of the energization controlled by the energization control unit and the value of the diagnostic voltage detected in a period during which the energization control unit energizes the plurality of the light emitting diodes among the remaining light emitting diodes.",
    "4. The fault diagnosis device according to claim 3, wherein, when energizing the plurality of light emitting diodes among the remaining light emitting diodes, the energization control unit is configured to control the energization so that the plurality of light emitting diodes among the remaining light emitting diodes have a brightness lower than that in a steady state thereof.",
    "5. The fault diagnosis device according to claim 1, further comprising a notification unit configured to notify occurrence of the fault in the light emitting unit based on a method different from lighting of the light emitting diodes in the controlled state of the energization, when the fault in the light emitting unit is detected by the fault detection unit.",
    "6. The fault diagnosis device according to claim 1, wherein the energization control unit is configured so as not to impair safety of a user who uses the robot during the energization of the light emitting diodes regardless of the operating state of the robot.",
    "7. The fault diagnosis device according to claim 1, wherein each emission color of the plurality of types of light emitting diodes is a color that is not likely to cause a user who uses the robot to erroneously recognize an operating state of the robot during the energization of the light emitting diodes by the energization control unit regardless of the operating state of the robot.",
    "8. The fault diagnosis device according to claim 1, wherein the light emitting diodes of the light emitting unit include a red light emitting diode, a green light emitting diode, and a blue light emitting diode, which are three light emitting diodes corresponding to three primary colors of light, the light emitting unit is configured to emit white light due to the red light emitting diode, the green light emitting diode, and the blue light emitting diode being energized when the state of the robot is a first state, in which a predetermined operation is automatically performed, the light emitting unit is configured to emit red light due to the red light emitting diode being energized when the state of the robot is a second state, in which an error with a relatively high degree of importance has occurred, the light emitting unit is configured to emit yellow light due to the red light emitting diode and the green light emitting diode being energized when the state of the robot is a third state, in which an error with a relatively low degree of importance has occurred, the light emitting unit is configured to emit green light due to the green light emitting diode being energized when the state of the robot is a fourth state, which is an initialization state, and the light emitting unit is configured to emit blue light due to the blue light emitting diode being energized when the state of the robot is a fifth state, which is a direct teaching mode in which a user who uses the robot performs teaching by manually moving the robot.",
    "9. The fault diagnosis device according to claim 2, further comprising a notification unit configured to notify occurrence of the fault in the light emitting unit based on a method different from lighting of the light emitting diodes in the controlled state of the energization, when the fault in the light emitting unit is detected by the fault detection unit.",
    "10. The fault diagnosis device according to claim 3, further comprising a notification unit configured to notify occurrence of the fault in the light emitting unit based on a method different from lighting of the light emitting diodes in the controlled state of the energization, when the fault in the light emitting unit is detected by the fault detection unit.",
    "11. The fault diagnosis device according to claim 2, wherein the light emitting diodes of the light emitting unit include a red light emitting diode, a green light emitting diode, and a blue light emitting diode, which are three light emitting diodes corresponding to three primary colors of light, the light emitting unit is configured to emit white light due to the red light emitting diode, the green light emitting diode, and the blue light emitting diode being energized when the state of the robot is a first state, in which a predetermined operation is automatically performed, the light emitting unit is configured to emit red light due to the red light emitting diode being energized when the state of the robot is a second state, in which an error with a relatively high degree of importance has occurred, the light emitting unit is configured to emit yellow light due to the red light emitting diode and the green light emitting diode being energized when the state of the robot is a third state, in which an error with a relatively low degree of importance has occurred, the light emitting unit is configured to emit green light due to the green light emitting diode being energized when the state of the robot is a fourth state, which is an initialization state, and the light emitting unit is configured to emit blue light due to the blue light emitting diode being energized when the state of the robot is a fifth state, which is a direct teaching mode in which a user who uses the robot performs teaching by manually moving the robot.",
    "12. The fault diagnosis device according to claim 3, wherein the light emitting diodes of the light emitting unit include a red light emitting diode, a green light emitting diode, and a blue light emitting diode, which are three light emitting diodes corresponding to three primary colors of light, the light emitting unit is configured to emit white light due to the red light emitting diode, the green light emitting diode, and the blue light emitting diode being energized when the state of the robot is a first state, in which a predetermined operation is automatically performed, the light emitting unit is configured to emit red light due to the red light emitting diode being energized when the state of the robot is a second state, in which an error with a relatively high degree of importance has occurred, the light emitting unit is configured to emit yellow light due to the red light emitting diode and the green light emitting diode being energized when the state of the robot is a third state, in which an error with a relatively low degree of importance has occurred, the light emitting unit is configured to emit green light due to the green light emitting diode being energized when the state of the robot is a fourth state, which is an initialization state, and the light emitting unit is configured to emit blue light due to the blue light emitting diode being energized when the state of the robot is a fifth state, which is a direct teaching mode in which a user who uses the robot performs teaching by manually moving the robot.",
    "13. The fault diagnosis device according to claim 4, wherein the light emitting diodes of the light emitting unit include a red light emitting diode, a green light emitting diode, and a blue light emitting diode, which are three light emitting diodes corresponding to three primary colors of light, the light emitting unit is configured to emit white light due to the red light emitting diode, the green light emitting diode, and the blue light emitting diode being energized when the state of the robot is a first state, in which a predetermined operation is automatically performed, the light emitting unit is configured to emit red light due to the red light emitting diode being energized when the state of the robot is a second state, in which an error with a relatively high degree of importance has occurred, the light emitting unit is configured to emit yellow light due to the red light emitting diode and the green light emitting diode being energized when the state of the robot is a third state, in which an error with a relatively low degree of importance has occurred, the light emitting unit is configured to emit green light due to the green light emitting diode being energized when the state of the robot is a fourth state, which is an initialization state, and the light emitting unit is configured to emit blue light due to the blue light emitting diode being energized when the state of the robot is a fifth state, which is a direct teaching mode in which a user who uses the robot performs teaching by manually moving the robot.",
    "14. A robot system, comprising: an industrial robot; a light emitting unit installed in the robot, the light emitting unit including (i) a plurality of types of light emitting diodes that emit different emission colors when the light emitting diodes are individually energized, and (ii) a plurality of switches that selectively switch on and off energization of the light emitting diodes, the different emission colors showing a robot state of the robot including operating states of the robot and a fault caused in the light emitting unit; an energization control unit configured to selectively control on and off states of the switches so that the energization of the light emitting diodes are selectively controlled; a voltage detection unit configured to detect, as a diagnostic voltage, a unique terminal voltage of the light emitting diodes when the energization control unit controls the switches, the unique terminal voltage being different depending on whether the robot is in the operating states or whether the fault is caused in the light emitting unit; and a fault detection unit configured to detect the fault caused in the light emitting unit based on a state of the energization controlled by the energization control unit and a value of the diagnostic voltage detected by the voltage detection unit.",
    "15. The robot system according to claim 14, wherein, when the operating state of the robot shows an operating state in which only one of the light emitting diodes in the light emitting unit is energized, the energization control unit is configured to energize one of remaining light emitting diodes other than the one of the light emitting diodes, and the fault detection unit is configured to detect the fault in the light emitting unit based on the state of the energization controlled by the energization control unit and the value of the diagnostic voltage detected in a period during which the energization control unit energizes the one of remaining light emitting diodes.",
    "16. The robot system according to claim 15, wherein the light emitting diodes of the light emitting unit include a red light emitting diode, a green light emitting diode, and a blue light emitting diode, which are three light emitting diodes corresponding to three primary colors of light, the light emitting unit is configured to emit white light due to the red light emitting diode, the green light emitting diode, and the blue light emitting diode being energized when the state of the robot is a first state, in which a predetermined operation is automatically performed, the light emitting unit is configured to emit red light due to the red light emitting diode being energized when the state of the robot is a second state, in which an error with a relatively high degree of importance has occurred, the light emitting unit is configured to emit yellow light due to the red light emitting diode and the green light emitting diode being energized when the state of the robot is a third state, in which an error with a relatively low degree of importance has occurred, the light emitting unit is configured to emit green light due to the green light emitting diode being energized when the state of the robot is a fourth state, which is an initialization state, and the light emitting unit is configured to emit blue light due to the blue light emitting diode being energized when the state of the robot is a fifth state, which is a direct teaching mode in which a user who uses the robot performs teaching by manually moving the robot."
  ],
  "description_excerpt": "The present invention relates to a robot fault diagnosis device and a robot system, and in particular, a robot fault diagnosis device preferably applied to an industrial robot, which is able to diagnose a fault in a light emitting unit that emits light of a color according to a state of the robot, and a robot system provided with such a fault diagnosis device.\n\nAs disclosed in JP 2016-43438 A, there have been robots having a light emitting unit that emits light of a color according to an operating state or the like. According to such a configuration, an operator can recognize the operating state or the like of the robot based on the color of light emitted from the light emitting unit. Such a light emitting unit includes three light emitting diodes corresponding to the three primary colors of light, that is, red, green, and blue. Each of these light emitting diodes can be individually energized to emit light of a color according to the state of the robot. In this specification, a light emitting diode may also be referred to as an LED.\n\n[PTL 1] JP 2016-43438 A\n\nIn the above configuration, when a fault occurs in the LEDs constituting the light emitting unit or components for driving these LEDs, the light emitting unit may emit light of a color different from the color corresponding to the state of the robot. This may impair the safety of the operator using the robot to perform a predetermined operation. For example, when the color of light emitted from the light emitting unit is a color indicative of a direct teaching mode although the state of the robot is an automatic mode, the problem described below occurs.",
  "cpc": [
    "H05B 45/54",
    "B25J 9/0081",
    "B25J 9/1653",
    "B25J 9/1674",
    "B25J 9/1679",
    "G01R 31/2635",
    "H05B 45/52"
  ],
  "ipc": [
    "B25J 9/16",
    "G01R 31/26",
    "H05B 45/10",
    "H05B 45/52",
    "H05B 45/54",
    "H05B 47/115"
  ],
  "assignees": [
    "Denso Wave Inc"
  ],
  "inventors": [
    "Syu KATAYAMA"
  ],
  "filing_date": "2020-09-18",
  "publication_date": "2023-02-14",
  "grant_date": "2023-02-14",
  "priority_date": "2019-09-18",
  "application_number": "US-202017025121-A",
  "family_id": "74868800",
  "cited_by_count": 0,
  "citations": [
    "US20050111231A1",
    "US20100097817A1",
    "US20110254554A1",
    "JP2016043438A",
    "US20210044081A1",
    "US20210163028A1"
  ]
}