Robot arrangement and method for controlling a robot

Patent metadata

Field	Value
Publication number	US-9694497-B2
Application number	US-201214414050-A
Country	US
Kind code	B2
Filing date	Jul 10, 2012
Priority date	Jul 10, 2012
Publication date	Jul 4, 2017
Grant date	Jul 4, 2017

Abstract

A method for controlling a robot, which is designed to be operated in a working mode, in which a part of the robot is moved at a speed at which there is a risk of injury to a person. The working mode is deactivated if a safety device detects that the person has entered an action region of the displaceable part. The aim is to make close cooperation possible between the person and the robot. A sensor unit determines a position and a posture of the person while the person is outside the action region of the part. A prediction unit determines an action region of the person. A collision monitoring unit monitors whether the two action regions overlap. The robot can optionally be switched from the working mode into a safety mode.

First claim

What is claimed is:

1. A method for controlling a robot in an industrial environment, comprising:
determining by a camera of a safeguarding apparatus a position and body posture of a person situated outside of an action range of a movable part of a robot;
determining an action range of the person by a monitoring computer of the safeguarding apparatus in response to the determined body posture to thereby define the action range by locations expected to be reachable within a predetermined time interval by the person, wherein the monitoring computer predicts a movement of the person based on a behavior rule prescribed for a behavior of the person in a surrounding of the robot, said person always having a right-of-way and said person not stopping if said person crosses a path of the robot;
determining a risk class RK0 which indicates no danger of a collision, or a risk class RK1 which indicates no acute risk of a collision but the person has the possibility to enter into a collision zone such that the robot is prepared, or a risk class RK2 which indicates that the person is too close to the robot such that there is an acute risk of a collision by the monitoring computer in response to data received by the camera;
checking by a collision monitoring computer of the safeguarding apparatus whether the action range of the person and the action range of the movable part intersect; and
switching the robot from a work mode into a safety mode to reduce a speed with which the movable part moves or to guide the movable part past the person, in the event the action range of the person and the action range of the movable part intersect so as to avoid a collision of the person with the movable part and injury to the person.

2. The method of claim 1 , wherein the action range of the person is determined by ascertaining at least one movement vector of at least one limb and/or a head of the person.

3. The method of claim 1 , wherein the action range of the person is determined by ascertaining a muscle activity of the person.

4. The method of claim 1 , wherein the action range of the person is determined by ascertaining a direction of view of the person.

5. The method of claim 1 , wherein the action range of the person is determined by a pressure sensor of the camera to ascertain a weight distribution of the person standing on a floor.

6. The method of claim 1 , wherein the camera matches a skeleton model to an observed body posture of the person.

7. The method of claim 6 , further comprising comparing current position values of joint points of the skeleton model to predetermined intervals of possible position values, and assigning a totality of the current position values to one of a plurality of predetermined posture types.

8. The method of claim 1 , wherein the camera simulates at least the movable part of the robot by a skeleton model.

9. The method of claim 1 , wherein the monitoring computer predicts a movement of the person based on a work procedure description, which describes a sequence of work steps which are to be carried out by the person in a surrounding of the robot.

10. The method of claim 1 , wherein the prediction unit determines a movement of the movable part based on a programming of the robot and the action range of the movable part as a function of time forms a basis, when the action range of the person and the action range of the movable part intersect.

11. The method of claim 1 , wherein a transition duration, which the robot requires to change from the work mode into the safety mode, is used as a time interval by the monitoring computer.

12. The method of claim 1 , further comprising determining by the collision monitoring unit a time duration until a predicted entry of the person into the action range of the movable part, and delaying a switchover by the robot from the work mode to the safety mode such that the robot assumes the safety mode after elapse of the time duration.

13. The method of claim 1 , wherein the action range of the person and the checking whether the action range of the person and the action range of the movable part intersect are executed repeatedly at predetermined times.

14. A robot arrangement for a handling system in an industrial environment, comprising:
a robot including a drive and a part which is movable by the drive; and
a safeguarding apparatus including
a camera configured to determine a position and body posture of a person situated outside of an action range of the movable part of the robot,
a monitoring computer configured to determine an action range of the person in response to the determined body posture to thereby define the action range by locations expected to be reachable within a predetermined time interval by the person, wherein the monitoring computer is configured to predict a movement of the person based on a behavior rule prescribed for a behavior of the person in a surrounding of the robot, said person always having a right-of-way and said person not stopping if said person crosses a path of the robot,
the monitoring computer configured to determine a risk class RK0 which indicates no danger of a collision, or a risk class RK1 which indicates no acute risk of a collision but the person has a possibility to enter into a collision zone such that the robot is prepared, or a risk class RK2 which indicates that the person is too close to the robot such that there is an acute risk of a collision in response to data received by the camera; and
a collision monitoring computer configured to check whether the action range of the person and the action range of the movable part intersect and switching the robot from a work mode into a safety mode to reduce a speed with which the movable part moves or to guide the movable part past the person, in the event the action range of the person and the action range of the movable part intersect so as to avoid a collision of the person with the movable part and injury to the person.

Assignees

• Burmeister Sören
• Dürr Matthias
• Siemens Ag

Inventors

• Burmeister Sören
• Dürr Matthias

Classifications

• G06T7/251

  involving models · CPC title

• Y10S901/09

  Closed loop, sensor feedback controls arm movement · CPC title

• G05B2219/40201

  Detect contact, collision with human · CPC title

• G06T2207/10016

  Video; Image sequence · CPC title

• B25J9/1697

  Vision controlled systems · CPC title