Method for determining possible positions of a robot arm

• US 9,144,902 B2
• Filed: 04/18/2013
• Issued: 09/29/2015
• Est. Priority Date: 05/15/2012
• Status: Active Grant

• Current Assignee: KUKA Laboratories GmbH (Midea Group Co., Ltd)
• Original Assignee: KUKA Roboter GmbH (Midea Group Co., Ltd)
• Inventors: Scheurer, Christian, Zimmermann, Uwe E., Sharma, Shashank
• Primary Examiner(s): HOLLOWAY, JASON R
• Application Number:
  US13/865,665
• Publication Number:
  US 20130310982A1
• Time in Patent Office: 894 Days
• Field of Search: 700/247, 700/250, 700/251, 700/253, 700/262, 700/263, 901/1
• US Class Current: 1/1
• CPC Class Codes: B25J 5/00 Manipulators mounted on wheels or on carriages B25J1/00 takes precedence; programme-controlled manipulators B25J9/00 ; vehicle aspects B60, B62, e.g. remote-controlled steering for motor vehicles B62D1/24; control of position of vehicles G05D1/00
• CPC Class Codes: B25J 5/007 mounted on wheels
• CPC Class Codes: B25J 9/162 Mobile manipulator, movable base with manipulator arm mounted on it
• CPC Class Codes: B25J 9/1664 characterised by motion, path, trajectory planning
• CPC Class Codes: B25J 9/1666 Avoiding collision or forbidden zones
• CPC Class Codes: G05B 2219/35354 Polar coordinates, turntable
• CPC Class Codes: G05B 2219/39022 Transform between measuring and manipulator coordinate system
• CPC Class Codes: G05B 2219/40298 Manipulator on vehicle, wheels, mobile
• CPC Class Codes: Y10S 901/01 Mobile robot
• CPC Class Codes: Y10S 901/15 Jointed arm

Abstract

The invention relates to a method for determining possible positions of a robot arm of a robot. The robot arm comprises a frame, numerous links, disposed successively, which can move in relation to one another, with respect to axes. First, a target position and target orientation in space for a robot arm or a tool center point assigned to an end effector attached to the robot arm, are defined, to which a reference coordinate system having polar coordinates is assigned. Subsequently, potential possible positions of the frame of the robot arm in space and in the polar coordinates of the reference coordinate system are determined on the basis of the geometry of the robot arm, such that the tool center point can assume the defined target position and target orientation.

Claims

1. A method for determining possible positions of a robot arm of a robot, wherein the robot arm comprises a frame, a plurality of successively arranged links that can move in relation to one another with respect to axes, and drives for moving the links, the method comprising:

defining a target position and target orientation in space of a robot arm or a tool center point assigned to the robot arm or an end effector attached to the robot arm, to which a reference coordinate system having polar coordinates is assigned;

determining with a computer potential possible positions of the frame of the robot arm in space and in the polar coordinates of the reference coordinate system, based on the geometry of the robot arm, such that the tool center point can assume the defined target position and target orientation; and

locating the frame at one of the determined positions;

wherein the robot is a mobile robot; and

a first polar coordinate defines the distance of the mobile robot from the origin of the reference coordinate system, a second polar coordinate defines a direction of travel of the mobile robot, and a third polar coordinate defines an orientation of the mobile robot with respect to the reference coordinate system.

2. The method according to claim 1, further comprising defining the target position and target orientation of the tool center point in the coordinates of a stationary global coordinate system.

3. The method according to claim 1, wherein the potential possible positions lie within a sphere, the center of which is the tool center point in its target position.

4. The method according to claim 1, further comprising:

determining the possible positions of the frame of the robot arm based on the determined potential possible positions and on at least one boundary condition, which limits the potential possible positions of the frame.

5. The method according to claim 4, wherein the at least one boundary condition limiting the potential possible positions of the frame is a surface, onto which the frame of the robot arm may be attached.

6. The method according to claim 4, wherein the robot comprises at least one linear axis, by means of which the frame of the robot arm can be moved linearly, such that the boundary condition limiting the potential possible positions of frame is determined through the extension, or extensions, respectively, of the at least one linear axis.

7. The method according to claim 4, wherein the robot includes a mobile support device having drives for moving said support device, to which the robot arm, together with its frame, is attached, and wherein the boundary condition limiting the potential possible positions of the frame represents a possible position or location of the support device.

8. The method according to claim 7, wherein the mobile support device is configured as a transport vehicle having wheels, and the drives for the mobile support device are configured for moving the wheels.

9. The method according to claim 1, further comprising determining the potential possible positions of the frame in terms of coordinates of a stationary global coordinate system, based on the polar coordinates of the reference coordinate system.