Patents by Inventor John-Erik Snell

John-Erik Snell has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 6226565
    Abstract: A method for control of the movement of the movement of an industrial robot along a given track (P1-P4) with a desired track speed (v), which industrial robot has a number of movement axes and for each axis servo equipment for control of the axis movement in accordance with reference values ({overscore (&tgr;)}korr) supplied thereto. First, those axis angles ({overscore (&phgr;)}i) which are needed for assuming the next position on the track are calculated. In dependence on the calculated axis angles and a first mathematical model, which describes the static and dynamic properties of the robot, for each one of the movement axes that torque ({overscore (&tgr;)}=(&tgr;1, &tgr;2 . . . &tgr;6)) is calculated which is required for assuming the next position. The load (t) is calculated at one or more mechanically critical points for the calculated axis angles ({overscore (&phgr;)}i) with the aid of a second mathematical model, which describes the load of the robot at the critical points.
    Type: Grant
    Filed: July 10, 1998
    Date of Patent: May 1, 2001
    Assignee: Asea Brown Boveri AB
    Inventors: Staffan Elfving, John-Erik Snell
  • Patent number: 6205839
    Abstract: An equipment for calibration of an industrial robot which has a plurality of axes of rotation and wherein, the equipment comprises a measuring device is adapted for rotatable connection to a reference point the position of which is known, is adapted to be in contact with the robot, or a tool carried by the robot, during the calibration process, and has an axis of rotation which intersects the reference point when the measuring device is connected to the reference point. The measuring device further comprises a gravity sensor which is so mounted so that the axis of the gravity sensor is substantially parallel to the axis of rotation of the measuring device, whereby the gravity sensor measures the angle between the gravity vector and axis of rotation.
    Type: Grant
    Filed: September 25, 1997
    Date of Patent: March 27, 2001
    Assignee: Asea Brown Bovreri AB
    Inventors: Torgny BrogÄrdh, John-Erik Snell
  • Patent number: 5907229
    Abstract: A method for calibration of an industrial robot is provided. A calibration device comprising devices for emitting a calibration beam within the working range of the robot, and an interruption detector which detects an interruption in the calibration beam are arranged. During the calibration process, a calibration tool supported by the robot hand and comprising a sphere with a known radius is moved towards the calibration beam. When an interruption in the calibration beam is detected, the output signals from the position transducers of the robot axes are read and stored. This process is repeated a plurality of times with different configurations of the robot. Thereafter, the calibration parameters of the robot are calculated based on the kinematic equations of the robot, the read and stored position transducer signals, and the known radius.
    Type: Grant
    Filed: September 29, 1997
    Date of Patent: May 25, 1999
    Assignee: Asea Brown Boveri AB
    Inventor: John-Erik Snell
  • Patent number: 5687293
    Abstract: In a calibration method for an industrial robot (2-6), a calibration tool (8) supported by the robot hand (6) is brought into contact a spherical calibration body (7) with a known radius. Thereafter, the output signals from the position transducers of the robot axes are read and stored. This method is repeated a plurality of times with different robot configurations. Thereafter, the calibration parameters of the robot are calculated starting from the kinematic equations of the robot, a model of the relationship between axial position and position transducer signal, the known radius of the calibration body, and the read and stored position transducer signals.
    Type: Grant
    Filed: October 25, 1994
    Date of Patent: November 11, 1997
    Assignee: Asea Brown Boveri AB
    Inventor: John-Erik Snell
  • Patent number: 5590034
    Abstract: A method for controlling an industrial robot such that a tool supported by the robot is able to follow a path which is determined by a number of consecutive points, and wherein the robot while following the path ends up near or a singularity. The robot has a plurality of movement axes and its configuration is determined by the angles of rotation of the movement axes. The angles of rotation which are to be assumed by the robot in order to obtain the desired position and orientation for the tool at the next point on the path are calculated by an iterative method. The ratio of the angular velocities of the axes to the velocity of the tool is given by a Jacobian matrix. By means of the Jacobian matrix it is determined whether the robot is at or near a singularity. The intention of the invention is to control the iteration such that the position of the tool remains correct through the singularity. A certain error in the orientation of the tool may be accepted.
    Type: Grant
    Filed: February 13, 1995
    Date of Patent: December 31, 1996
    Assignee: ASEA Brown Boveri AB
    Inventor: John-Erik Snell
  • Patent number: 5528116
    Abstract: In a calibration method for an industrial robot (2-6), a calibration tool (8) supported by the robot hand (6) is brought into contact with pairwise opposite side surfaces of a calibration body (7) with a known edge length. Thereafter, the output signals from the position transducers of the robot axes are read and stored. This method is repeated a plurality of times with different robot configurations. Thereafter, the calibration parameters of the robot are calculated starting from the kinematic equations of the robot, a model of the relationship between axial position and position transducer signal, the known edge lengths of the calibration body, and the read and stored position transducer signals. (FIG.
    Type: Grant
    Filed: May 9, 1994
    Date of Patent: June 18, 1996
    Assignee: Asea Brown Boveri AB
    Inventor: John-Erik Snell