Patents by Inventor Frank J. Reifler

Frank J. Reifler 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: 9207314
    Abstract: A state estimation system utilizing an Interacting Multiple Model (IMM) architecture and algorithms that can transition between different regimes of operation described by multiple models. Each individual model includes states, whose dynamics can be modeled, as well as extrinsic parameters, such as inputs to the system and sensor biases, whose dynamics cannot be modeled, but which are constrained to lie within a known range of values.
    Type: Grant
    Filed: June 20, 2012
    Date of Patent: December 8, 2015
    Assignee: Lockheed Martin Corporation
    Inventors: Purusottam Mookerjee, Frank J. Reifler
  • Patent number: 8515712
    Abstract: Information filters provide state estimation of a system when measurements provided by sensors are incomplete in that the states of the system are unobservable until a large number of measurements are collected. An example is the operation of multiple, asynchronous, one- or two-dimensional sensors to track an object in three-dimensional space. The disclosure describes an information filter that minimizes mean square estimation errors and provides accurate covariances for systems driven by unknown arbitrary time-varying inputs with unspecified dynamics but known bounds.
    Type: Grant
    Filed: August 26, 2010
    Date of Patent: August 20, 2013
    Assignee: Lockheed Martin Corporation
    Inventors: Purusottam Mookerjee, Frank J. Reifler
  • Patent number: 7719461
    Abstract: The invention, called “ORSE Track Fusion”, combines sensor tracks from dispersed sites, when limited communication bandwidth does not permit sharing of individual measurements. Since estimation errors due to maneuver biases are not independent for each sensor, optimal fusion of tracks produced by Kalman filters requires transmission of all the filter gain matrices used to update each sensor track prior to the fusion time. For this reason, prior art has resorted to suboptimal designs. ORSE Track Fusion according to aspects of the invention overcomes this disadvantage by propagating, transmitting, and fusing separately calculated covariance matrices for random and bias estimation errors. Furthermore, with ORSE, each sensor can have its own criteria in forming its track, and track fusion can be performed with different criteria at each processing site. Thus, ORSE Track Fusion has the unique flexibility to optimize track fusion simultaneously for multiple criteria to serve multiple users.
    Type: Grant
    Filed: August 5, 2008
    Date of Patent: May 18, 2010
    Assignee: Lockheed Martin Corporation
    Inventors: Purusottam Mookerjee, Frank J. Reifler
  • Patent number: 7375679
    Abstract: This invention relates to state estimation after processing time-delayed measurements with unknown biases that may vary arbitrarily in time within known physical bounds. These biased measurements are obtained from systems characterized by state variables and by multidimensional parameters, for which the latter are also unknown and may vary arbitrarily in time within known physical bounds. If a measurement is time-late, apply the measurements to an out-of-sequence filter using a mean square optimization criterion that accounts for all sources of uncertainty and delay time, to produce estimates of the true states of the system. If the measurement is not time-late, apply the measurements to an in-sequence filter using a mean square optimization criterion that accounts for all sources of uncertainty to produce estimates of the true states of the system. The estimates are applied to one of (a) making a decision, (b) operating a control system, and (c) controlling a process.
    Type: Grant
    Filed: August 16, 2005
    Date of Patent: May 20, 2008
    Assignee: Lockheed Martin Corporation
    Inventors: Purusottam Mookerjee, Frank J. Reifler
  • Patent number: 7277047
    Abstract: This invention relates to sate estimation after processing measurements with unknown biases that may vary arbitrarily in time within known physical bounds. These biased measurements are obtained from systems characterized by state variables and by multidimensional parameters, for which the latter are also known and may vary arbitrarily in time within known physical bounds. The measurements are processed by a filter using a mean square optimization criterion that accounts for random and biased measurement errors, as well as parameters excursions, to produce estimates of the true states of the system. The estimates are applied to one of (a) making a decision, (b) operating a control system, and (c) controlling a process.
    Type: Grant
    Filed: February 6, 2006
    Date of Patent: October 2, 2007
    Assignee: Lockheed Martin Corporation
    Inventors: Purusottam Mookerjee, Frank J. Reifler
  • Patent number: 7180443
    Abstract: State estimation of a system having multidimensional parameters, which are unknown, arbitrarily time-varying, but bounded, in addition to state variables, is performed by initializing the state estimate and matrices representing its covariance and bias coefficients which linearly relate initial state estimation errors to the parameter errors. System matrices ?, ?, F, G and the mean value ? of unknown, time-varying, but bounded parameters ? are determined. A matrix ? is generated, representing their physical bounds. The state estimate {circumflex over (x)}(k|k) and matrices M(k|k) and D(k|k), characterizing the effects of measurement errors and parameter uncertainty, are extrapolated to generate {circumflex over (x)}(k+1|k), M(k+1|k), and D(k+1|k). The measurement noise covariance N is determined. The filter gain matrix K is calculated.
    Type: Grant
    Filed: March 16, 2005
    Date of Patent: February 20, 2007
    Assignee: Lockheed Martin Corporation
    Inventors: Purusottam Mookerjee, Frank J. Reifler
  • Patent number: 7009554
    Abstract: This invention relates to state estimation after processing measurements with time delays from multiple sensors of systems characterized by state variables and by multidimensional parameters, for which the latter are unknown and may vary arbitrarily in time within known physical bounds. If a measurement is time-late, apply the measurement to an out-of-sequence filter that uses a mean square optimization criterion that accounts for measurement errors and said bounding values, as well as the delay time, to optimally produce estimates of the true states of the system. If the measurement is not time-late, apply the measurements to an in-sequence filter that uses a mean square optimization criterion that accounts for measurement errors and said bounding values, to produce estimates of the true states of the system. The estimates are applied to one of (a) making a decision relating to the system, (b) operating a control system, and (c) controlling a process.
    Type: Grant
    Filed: March 30, 2005
    Date of Patent: March 7, 2006
    Assignee: Lockheed Martin Corporation
    Inventors: Purusottam Mookerjee, Frank J. Reifler