{
  "patent_number": "US 9855653",
  "country": "US",
  "title": "Robots That Don't Get Stuck: A Master-Slave Control System",
  "original_title": "Master-slave system",
  "summary": "This patent describes a robot control system where a human-operated 'master' robot guides a 'slave' robot, preventing either from getting into awkward, uncontrollable positions by carefully planning the master robot's movements.",
  "what_it_does": "This system connects a master robot, which is a haptic device controlled by a human operator, to a slave robot that performs tasks. It uses sensors to measure the movements of both robots (master displacement sensor, slave displacement sensor) and actuators to control their forces (master actuator, slave actuator). A 'master target displacement calculating device' takes the slave robot's movement and maps it to a desired movement for the master robot. Crucially, this mapping is designed to avoid any 'singular configurations' for the master robot, which are positions where the robot can get stuck or lose control. The system also uses a 'slave target driving force calculating device' to control the slave robot based on the force the operator applies to the master robot. This setup means the operator feels the slave robot's actions without needing an extra sensor on the slave robot to measure forces it applies to its surroundings, and it solves the problem of robots getting stuck for both the master and slave robots. For example, a surgeon using a haptic controller (master robot) to perform delicate surgery with a robotic arm (slave robot) would experience smooth, precise control without the robotic arm ever locking up.",
  "what_it_does_not_cover": [
    "Does not cover master-slave systems that require a separate working force sensor on the slave robot to measure forces applied to the environment (Claim 1).",
    "Does not cover systems where the master robot's movement mapping allows it to enter a singular configuration, a position where it loses control (Claim 1).",
    "Does not cover systems where the operator feels the master robot's own internal movements or dynamics, rather than just the slave robot's actions (Claim 1).",
    "Does not cover systems where the calculation for the master robot's inverse kinematics needs complex, iterative numerical methods to find a solution (Claim 3).",
    "Does not cover systems where the master robot has more than six degrees of freedom, or where its rotational joints do not cross at a single point (Claim 4)."
  ],
  "filed": "2014-11-05",
  "granted": "2018-01-02",
  "expires": "2034-11-05",
  "status": "active",
  "holder": "Muscle",
  "holder_url": "https://patentbrief.org/company/muscle",
  "inventors": [
    {
      "name": "Ryo Kikuuwe",
      "url": "https://patentbrief.org/inventor/ryo-kikuuwe"
    },
    {
      "name": "Katsuya Kanaoka",
      "url": "https://patentbrief.org/inventor/katsuya-kanaoka"
    }
  ],
  "times_cited": 1,
  "tags": [
    "robotics",
    "medical_devices",
    "telecommunications",
    "software",
    "mechanical"
  ],
  "abstract": "A master-slave system ( 1 ) according to the present invention includes at least one master displacement sensor (Pm 1 to Pm 3 ) for measuring a master displacement for a master robot, at least one slave displacement sensor (Ps 1 to Ps 3 ) for measuring a slave displacement for a slave robot, a master target displacement calculating device ( 2 ) for mapping the slave displacement and thereby obtaining a master target displacement which is a target value for the master displacement corresponding to the slave displacement, and a master actuator (Am 1 to Am 3 ) for generating a master driving force to position-control the master robot on the basis of the master target displacement and the master displacement. The mapping is predefined such that a set of master target displacements excludes a singular configuration for the master robot. The master-slave system ( 1 ) renders it possible to solve a singular configuration problem for both the master robot and the slave robot.",
  "url": "https://patentbrief.org/patent/us/9855653/master-slave-system",
  "markdown_url": "https://patentbrief.org/patent/us/9855653/master-slave-system/md",
  "google_patents_url": "https://patents.google.com/patent/US9855653",
  "relatedPatents": [
    {
      "patentNumber": "11794345",
      "countryCode": "US",
      "title": "How One Person Can Control Two Robots as a Team",
      "url": "https://patentbrief.org/patent/us/11794345/unified-robotic-vehicle-systems-and-methods-of-control"
    },
    {
      "patentNumber": "12114954",
      "countryCode": "US",
      "title": "Uniform Scaling of Haptic Forces in Surgical Systems",
      "url": "https://patentbrief.org/patent/us/12114954/uniform-scaling-of-haptic-actuators"
    },
    {
      "patentNumber": "9949801",
      "countryCode": "US",
      "title": "How Surgical Robots Reconfigure Their Arms Without Moving the Tool Tip",
      "url": "https://patentbrief.org/patent/us/9949801/systems-and-methods-for-commanded-reconfiguration-of-a-surgical-manipulator-usin"
    },
    {
      "patentNumber": "9409292",
      "countryCode": "US",
      "title": "How a Snake Robot Uses Two Arms to Work Together",
      "url": "https://patentbrief.org/patent/us/9409292/serpentine-robotic-crawler-for-performing-dexterous-operations"
    },
    {
      "patentNumber": "8209052",
      "countryCode": "US",
      "title": "How a Robot Actuator Controls Force and Speed with Gears",
      "url": "https://patentbrief.org/patent/us/8209052/high-performance-differential-actuator-for-robotic-interaction-tasks"
    }
  ]
}