Patents by Inventor John T. Feddema

John T. Feddema 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: 6496765
    Abstract: A crane control system and method provides a way to generate crane commands responsive to a desired payload motion to achieve substantially pendulation-free actual payload motion. The control system and method apply a motion compensator to maintain a payload in a defined payload configuration relative to an inertial coordinate frame. The control system and method can further comprise a pendulation damper controller to reduce an amount of pendulation between a sensed payload configuration and the defined payload configuration. The control system and method can further comprise a command shaping filter to filter out a residual payload pendulation frequency from the desired payload motion.
    Type: Grant
    Filed: October 24, 2000
    Date of Patent: December 17, 2002
    Assignee: Sandia Corporation
    Inventors: Rush D. Robinett, III, Kenneth N. Groom, John T. Feddema, Gordon G. Parker
  • Patent number: 6442439
    Abstract: A command shaping control system and method for rotary boom cranes provides a way to reduce payload pendulation caused by real-time input signals, from either operator command or automated crane maneuvers. The method can take input commands and can apply a command shaping filter to reduce contributors to payload pendulation due to rotation, elevation, and hoisting movements in order to control crane response and reduce tangential and radial payload pendulation. A filter can be applied to a pendulation excitation frequency to reduce residual radial pendulation and tangential pendulation amplitudes.
    Type: Grant
    Filed: June 24, 1999
    Date of Patent: August 27, 2002
    Assignee: Sandia Corporation
    Inventors: Rush D. Robinett, III, Kenneth N. Groom, John T. Feddema, Gordon G. Parker
  • Patent number: 6438456
    Abstract: A handheld control device provides a way for controlling one or multiple mobile robotic vehicles by incorporating a handheld computer with a radio board. The device and software use a personal data organizer as the handheld computer with an additional microprocessor and communication device on a radio board for use in controlling one robot or multiple networked robots.
    Type: Grant
    Filed: April 24, 2001
    Date of Patent: August 20, 2002
    Assignee: Sandia Corporation
    Inventors: John T. Feddema, Raymond H. Byrne, Jon R. Bryan, John J. Harrington, T. Scott Gladwell
  • Patent number: 6377878
    Abstract: A decentralized fuzzy logic control system for one vehicle or for multiple robotic vehicles provides a way to control each vehicle to converge on a goal without collisions between vehicles or collisions with other obstacles, in the presence of noisy input measurements and a limited amount of compute-power and memory on board each robotic vehicle. The fuzzy controller demonstrates improved robustness to noise relative to an exact controller.
    Type: Grant
    Filed: June 23, 2000
    Date of Patent: April 23, 2002
    Assignee: Sandia Corporation
    Inventors: John T. Feddema, Brian J. Driessen, Kwan S. Kwok
  • Patent number: 6308791
    Abstract: The present invention provides a steerable vertical to horizontal energy transducer for mobile robots that less complex and requires less power than two degree of freedom tilt mechanisms. The present invention comprises an end effector that, when mounted with a hopping actuator, translates along axis (typically vertical) actuation into combined vertical and horizontal motion. The end effector, or foot, mounts with an end of the actuator that moves toward the support surface (typically a floor or the earth). The foot is shaped so that the first contact with the support surface is off the axis of the actuator. Off-axis contact with the support surface generates an on-axis force (typically resulting in vertical motion) and a moment orthogonal to the axis. The moment initiates a horizontal tumbling motion, and tilts the actuator so that its axis is oriented with a horizontal component and continued actuation generates both vertical and horizontal force.
    Type: Grant
    Filed: May 6, 1999
    Date of Patent: October 30, 2001
    Assignee: Sandia Corporation
    Inventors: Barry L. Spletzer, Gary J. Fischer, John T. Feddema
  • Patent number: 6247546
    Abstract: The present invention provides a hopping robot that includes a misfire tolerant linear actuator suitable for long trips, low energy steering and control, reliable low energy righting, miniature low energy fuel control. The present invention provides a robot with hopping mobility, capable of traversing obstacles significant in size relative to the robot and capable of operation on unpredictable terrain over long range. The present invention further provides a hopping robot with misfire-tolerant combustion actuation, and with combustion actuation suitable for use in oxygen-poor environments.
    Type: Grant
    Filed: May 6, 1999
    Date of Patent: June 19, 2001
    Assignee: Sandia Corporation
    Inventors: Barry L. Spletzer, Gary J. Fischer, Lisa C. Marron, Michael A. Martinez, Michael A. Kuehl, John T. Feddema
  • Patent number: 5908122
    Abstract: Methods and apparatuses for reducing the oscillatory motion of rotary crane payloads during operator-commanded or computer-controlled maneuvers. An Input-shaping filter receives input signals from multiple operator input devices and converts them into output signals readable by the crane controller to dampen the payload tangential and radial sway associated with rotation of the jib. The input signals are characterized by a hub rotation trajectory .gamma.(t), which includes a jib angular acceleration .gamma., a trolley acceleration x, and a load-line length velocity L. The system state variables are characterized by a tangential rotation angle .theta.(t) and a radial rotation angle .phi.(t) of the load-line. The coupled equations of motion governing the filter are non-linear and configuration-dependent. In one embodiment, a filter is provided between the operator and the crane for filtering undesired frequencies from the angular .gamma. and trolley x velocities to suppress payload oscillation.
    Type: Grant
    Filed: February 28, 1997
    Date of Patent: June 1, 1999
    Assignee: Sandia Corporation
    Inventors: Rush D. Robinett, Gordon G. Parker, John T. Feddema, Clark R. Dohrmann, Ben J. Petterson
  • Patent number: 5785191
    Abstract: A system and method for eliminating swing motions in gantry-style cranes while subject to operator control is presented. The present invention comprises an infinite impulse response ("IIR") filter and a proportional-integral ("PI") feedback controller (50). The IIR filter receives input signals (46) (commanded velocity or acceleration) from an operator input device (45) and transforms them into output signals (47) in such a fashion that the resulting motion is swing free (i.e., end-point swinging prevented). The parameters of the IIR filter are updated in real time using measurements from a hoist cable length encoder (25). The PI feedback controller compensates for modeling errors and external disturbances, such as wind or perturbations caused by collision with objects. The PI feedback controller operates on cable swing angle measurements provided by a cable angle sensor (27). The present invention adjusts acceleration and deceleration to eliminate oscillations.
    Type: Grant
    Filed: May 15, 1996
    Date of Patent: July 28, 1998
    Assignee: Sandia Corporation
    Inventors: John T. Feddema, Ben J. Petterson, Rush D. Robinett, III