Patents by Inventor Frank L. Lewis

Frank L. Lewis 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: 10809678
    Abstract: Disclosed are systems and methods relating to managing and sharing resources within a spatially-distributed electrical power network in a fully distributed fashion. The electrical power network includes source nodes each having a power source and a local controller. The electrical power network includes a physical layer where the source nodes are connected to a power distribution network including one or more loads. The electrical power network also includes a communication layer for communicating power information between source nodes and neighbor source nodes of the electrical power network.
    Type: Grant
    Filed: March 15, 2016
    Date of Patent: October 20, 2020
    Assignee: Board of Regents, The University of Texas System
    Inventors: Vahidreza Nasirian, Ali Davoudi, Frank L. Lewis
  • Publication number: 20190354100
    Abstract: Disclosed are systems and methods relating to dynamically updating control systems according to observations of behaviors of neighboring control systems in the same environment. A control policy for an agent device is established based on an incomplete knowledge of an environment and goals. State information from neighboring agent devices can be collected. A belief in an intention of the neighboring agent device can be determined based on the state information and without knowledge of the actual intention of the neighboring agent device. The control policy can be updated based on the updated belief.
    Type: Application
    Filed: May 14, 2019
    Publication date: November 21, 2019
    Inventors: Victor G. Lopez Mejia, Yan Wan, Frank L. Lewis
  • Publication number: 20160276830
    Abstract: Disclosed are systems and methods relating to managing and sharing resources within a spatially-distributed electrical power network in a fully distributed fashion. The electrical power network includes source nodes each having a power source and a local controller. The electrical power network includes a physical layer where the source nodes are connected to a power distribution network including one or more loads. The electrical power network also includes a communication layer for communicating power information between source nodes and neighbor source nodes of the electrical power network.
    Type: Application
    Filed: March 15, 2016
    Publication date: September 22, 2016
    Applicant: Board of Regents, The University of Texas System
    Inventors: Vahidreza Nasirian, Ali Davoudi, Frank L. Lewis
  • Patent number: 7548011
    Abstract: Methods and apparatuses for sensing and adjusting lateral motion in a comb drive actuated MEMS device are provided. If lateral motion is sensed by a lateral motion sensor coupled to the comb drive actuated MEMS device, and the lateral motion is greater than a reference value, a feedback controller adjusts the lateral motion by providing a drive signal to a comb drive electrode of a comb drive actuator.
    Type: Grant
    Filed: May 18, 2006
    Date of Patent: June 16, 2009
    Assignee: The Board of Regents of the University of Texas System
    Inventors: Bruno Borovic, Frank L. Lewis, Ai Qun Liu, Dan O. Popa
  • Publication number: 20070267939
    Abstract: Methods and apparatuses for sensing and adjusting lateral motion in a comb drive actuated MEMS device are provided. If lateral motion is sensed by a lateral motion sensor coupled to the comb drive actuated MEMS device, and the lateral motion is greater than a reference value, a feedback controller adjusts the lateral motion by providing a drive signal to a comb drive electrode of a comb drive actuator.
    Type: Application
    Filed: May 18, 2006
    Publication date: November 22, 2007
    Inventors: Bruno Borovic, Frank L. Lewis, Ai Qun Liu, Dan O. Popa
  • Patent number: 7080055
    Abstract: Methods and apparatuses for backlash compensation. A dynamics inversion compensation scheme is designed for control of nonlinear discrete-time systems with input backlash. The techniques of this disclosure extend the dynamic inversion technique to discrete-time systems by using a filtered prediction, and shows how to use a neural network (NN) for inverting the backlash nonlinearity in the feedforward path. The techniques provide a general procedure for using NN to determine the dynamics preinverse of an invertible discrete time dynamical system. A discrete-time tuning algorithm is given for the NN weights so that the backlash compensation scheme guarantees bounded tracking and backlash errors, and also bounded parameter estimates. A rigorous proof of stability and performance is given and a simulation example verifies performance. Unlike standard discrete-time adaptive control techniques, no certainty equivalence (CE) or linear-in-the-parameters (LIP) assumptions are needed.
    Type: Grant
    Filed: October 2, 2001
    Date of Patent: July 18, 2006
    Inventors: Javier Campos, Frank L. Lewis
  • Publication number: 20040015933
    Abstract: Methods and apparatuses for backlash compensation. A dynamics inversion compensation scheme is designed for control of nonlinear discrete-time systems with input backlash. The techniques of this disclosure extend the dynamic inversion technique to discrete-time systems by using a filtered prediction, and shows how to use a neural network (NN) for inverting the backlash nonlinearity in the feedforward path. The techniques provide a general procedure for using NN to determine the dynamics preinverse of an invertible discrete time dynamical system. A discrete-time tuning algorithm is given for the NN weights so that the backlash compensation scheme guarantees bounded tracking and backlash errors, and also bounded parameter estimates. A rigorous proof of stability and performance is given and a simulation example verifies performance. Unlike standard discrete-time adaptive control techniques, no certainty equivalence (CE) or linear-in-the-parameters (LIP) assumptions are needed.
    Type: Application
    Filed: October 2, 2001
    Publication date: January 22, 2004
    Applicant: Board of Regents, The University of Texas System
    Inventors: Javier Campos, Frank L. Lewis
  • Patent number: 6611823
    Abstract: Methods and systems for backlash compensation. Restrictive assumptions on the backlash nonlinearity (e.g. the same slopes of the lines, etc.) are not required. The compensator scheme has dynamic inversion structure, with a neural network in the feedforward path that approximates the backlash inversion error plus filter dynamics needed for backstepping design. The neural network controller does not require preliminary off-line training. Neural network tuning is based on a modified Hebbian tuning law, which requires less computation than backpropagation. The backstepping controller uses a practical filtered derivative, unlike the usual differentiation required by earlier backstepping routines. Rigorous stability proofs are given using Lyapunov theory. Simulation results show that the proposed compensation scheme is an efficient way of improving the tracking performance of a vast array of nonlinear systems with backlash.
    Type: Grant
    Filed: April 20, 2000
    Date of Patent: August 26, 2003
    Assignee: Board of Regents, The University of Texas System
    Inventors: Rastko R. Selmic, Frank L. Lewis, Anthony J. Calise, Michael B. McFarland
  • Patent number: 6185469
    Abstract: The invention comprises in various embodiments controllers and apparatus for testing flexible manufacturing systems and methods of operating same. The controller includes a computer, a program, output lines from the computer, and devices connected to the output lines. The program uses matrix logic equations to determine when to start and stop jobs. The devices start and stop individual resources in response to logic signals from the computer. In one embodiment, the controller obtains sensor feedback on the distribution of work pieces and available resources in the manufacturing system. The invention also includes an apparatus and methods for testing a flexible manufacturing system. In response to the input of initial data, the apparatus for testing a flexible manufacturing system solves matrix equations and determines the activity and/or production of the manufacturing system.
    Type: Grant
    Filed: May 11, 1998
    Date of Patent: February 6, 2001
    Assignee: Board of Regents, The University of Texas System
    Inventors: Frank L. Lewis, Diego A. Tacconi, Octavian C. Pastravanu, Ayla Gurel