Robot simulation system which simulates takeout process of workpieces

{
  "publication_number": "US9529945B2",
  "country": "US",
  "kind": "B2",
  "title": "Robot simulation system which simulates takeout process of workpieces",
  "abstract": "A robot simulation system includes a first plane calculation part which calculates a group of first planes extending through focal points of two camera models and divide the fields of vision of the two camera models at equal intervals when capturing a measurement region, a second plane calculation part which calculates a group of second planes which intersect the first planes and extend along boundaries of light-dark contrast formed on the measurement region with stripe shaped patterns of light from the projector model, an intersecting line calculation part which calculates a plurality of intersecting lines between the first planes and the second planes, a three-dimensional information calculation part which calculates positions of intersecting points between the intersecting lines and surfaces of the workpiece models as three-dimensional information, and a position and posture calculation part which calculates positions and postures of the workpiece model based on the three-dimensional information.",
  "claims": [
    "1. A robot simulation system for simulating in a virtual space a takeout process for successively taking out a plurality of bulk stacked workpieces by a robot, based on three-dimensional information of the workpieces which is obtained by a range sensor including two cameras and a projector, the robot simulation system comprising a model placement part which places in the virtual space a robot model, a plurality of workpiece models, two camera models, and a projector model which three-dimensionally express the robot, the plurality of workpieces, and the two cameras and the projector of the range sensor, respectively, wherein the model placement part is configured to place the plurality of workpiece models in the virtual space in a bulk stacked state, and place the two camera models and the projector model in the virtual space so that fields of vision of the two camera models and a projection range of the projector model encompass a measurement region which is set for bulk stacked workpiece models, the robot simulation system further comprising: a first plane calculation part which calculates a group of first planes which extend through focal points of the two camera models and divide the fields of vision of the two camera models at equal intervals when capturing the measurement region; a second plane calculation part which calculates a group of second planes which intersect the group of first planes and extend through the projector model and boundaries of light-dark contrast which are formed on the measurement region when the projector model projects stripe shaped patterns of light on the measurement region; an intersecting line calculation part which calculates a plurality of intersecting lines between the group of first planes and the group of second planes; a three-dimensional information calculation part which calculates positions of a plurality of intersecting points between the plurality of intersecting lines and surfaces of the workpiece models as three-dimensional information of the workpiece models, a position and posture calculation part which calculates positions and postures of the workpiece models based on the three-dimensional information of the workpiece models, and a simulation run part which runs a simulation of the takeout process by the robot model based on the positions and postures of the workpiece models which are calculated by the position and posture calculation part.",
    "2. The robot simulation system according to claim 1, wherein the model placement part is configured to place a second camera which captures an image of the bulk stacked workpiece models in the virtual space, the robot simulation system further comprises a two-dimensional image acquisition part which acquires a two-dimensional image of the bulk stacked workpiece models from the second camera, and the position and posture calculation part is further configured to calculate positions and postures of the workpiece models, based on the three-dimensional information of the workpiece models and the two-dimensional image."
  ],
  "description_excerpt": "1. Field of the Invention\n\nThe present invention relates to a robot simulation system which simulates a takeout process by a robot for successively taking out bulk stacked workpieces.\n\n2. Description of the Related Art\n\nA robot simulation system is used for simulating a robot handling a workpiece or performing other predetermined operations in a virtual space. The results of simulation are utilized for evaluating the control program of the robot and for changing the program or the positional relationship of objects in the work space as necessary.\n\nA known robot simulation system which simulates a takeout process for successively holding and conveying bulk stacked workpieces to a predetermined position by a robot. In the related art, the takeout process is simulated by, for example, arranging a three-dimensional model of a camera, which detects the positions and postures of the workpieces, in a virtual space.\n\nJP2007-241857A discloses a robot simulation system which simulates off-line the operation of a robot which has a visual sensor. This robot simulation system is configured to identify a target workpiece model to be taken out and measure the position and posture of the target workpiece model, based on a two-dimensional virtual image which is obtained by a sensor model which captures an image of workpiece models in a virtual space.\n\nJP2007-326160A discloses a robot simulation system which is configured to obtain a virtual image of a workpiece by a camera model which is arranged in a virtual space. In this robot simulation system, a teaching point for the robot model is corrected based on the obtained virtual image.",
  "cpc": [
    "G06F 30/20",
    "B25J 19/04",
    "B25J 9/1671",
    "B25J 9/1687",
    "B25J 9/1697",
    "G05B 2219/40006",
    "G05B 2219/40053",
    "G05B 2219/40323",
    "G05B 2219/40515",
    "G06F 17/5009"
  ],
  "ipc": [
    "B25J 9/16",
    "G06F 17/50"
  ],
  "assignees": [
    "Fanuc Corp"
  ],
  "inventors": [
    "Hiroyuki Atohira",
    "Yoshiharu Nagatsuka"
  ],
  "filing_date": "2015-03-10",
  "publication_date": "2016-12-27",
  "grant_date": "2016-12-27",
  "priority_date": "2014-03-12",
  "application_number": "US-201514642961-A",
  "family_id": "54010278",
  "cited_by_count": 8,
  "citations": [
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    "US7876455B2",
    "WO2006013635A1",
    "JP2007241857A",
    "JP2007245283A",
    "JP2007326160A",
    "US20130204465A1",
    "US8326469B2",
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    "JP2009128191A",
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    "JP2011083882A",
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    "JP2013186088A",
    "JP2014013146A"
  ]
}