Patents Assigned to LITEF GmbH
  • Publication number: 20170167877
    Abstract: The invention relates to a controller (200) for controlling a rotation rate sensor, having a first control circuit (202) and a second control circuit (204). The first control circuit has a first control unit (210) for controlling an oscillation of the rotation rate sensor along a first direction, a first digital-to-analog converter (240) for converting a first digital control signal (215) output by the first control unit (210) into a first analog signal (245) with which the oscillation of the rotation rate sensor along the first direction is controlled, and a first analog-to-digital converter (250) for converting a first analog measurement signal (235) which describes the oscillation of the rotation rate sensor along the first direction into a first digital read-out signal (255) which is supplied to the first control unit (210).
    Type: Application
    Filed: April 17, 2015
    Publication date: June 15, 2017
    Applicant: NORTHROP GRUMMAN LITEF GMBH
    Inventors: RALF RICHARD OHMBERGER, STEFFEN ZIMMERMAN
  • Patent number: 9651380
    Abstract: The invention relates to an integrated optical coupler (1) comprising a substrate (3), at least two planar waveguides (4), which are arranged on or in the substrate (3) and consist of a material having a virtually isotropic refractive index (anisotropy of the refractive index of less than 10?6), and al least three monomode fibers (8, 9, 10) coupled to the planar waveguides (4). One of the monomode fibers (8) is a polarization-maintaining fiber. A fiber optic system according to the invention comprises an integrated optical coupler (1) according to the invention, a light source (21) that is suitable for generating light beams, and a first pigtail fiber (22), which is connected at one end to the light source (21) and at the other end to the polarization-maintaining fiber (8) of the integrated optical coupler (1).
    Type: Grant
    Filed: June 30, 2014
    Date of Patent: May 16, 2017
    Assignee: Northrop Grumman LITEF GmbH
    Inventors: Sven Voigt, Steffen Zimmermann
  • Patent number: 9518824
    Abstract: A control device comprises a sensor unit, which outputs a measurement signal, which reflects a deviation of an oscillator along a direction of excitation. A controller main unit derives a control signal for an actuator unit from the measurement signal and a harmonic set point signal such that the actuator unit counteracts a deviation of the deflection of the oscillator from a set amplitude of a harmonic resonance oscillation. A controller extension unit estimates actual-phase and actual-amplitude of a residual oscillation of the oscillator and synchronizes the harmonic set point signal with the residual oscillation at a deactivated actuator unit. The residual energy contained in the residual oscillation is used, in order to arrive faster at a defined operation state of the oscillator.
    Type: Grant
    Filed: October 15, 2012
    Date of Patent: December 13, 2016
    Assignee: Northrop Grumman LITEF GmbH
    Inventor: Markus Ruf
  • Patent number: 9518825
    Abstract: A fiber-optic Sagnac interferometer in a rotation rate sensor comprises a multifunctional integrated optical chip (MIOC) with a MIOC transfer function. A digital filter is connected upstream to the multi-functional integrated optical chip, whose filter transfer function corresponds basically to the inverse MIOC transfer function such that the MIOC transfer function is compensated by the filter transfer function. Corresponding coefficients of the filter transfer function may be determined in a main control loop.
    Type: Grant
    Filed: March 12, 2014
    Date of Patent: December 13, 2016
    Assignee: Northrop Grumman LITEF GmbH
    Inventors: Guenter Spahlinger, Olaf Deppe-Reibold
  • Publication number: 20160318616
    Abstract: A flight data memory module (1) has a data memory device (2) for storing data, a data receiver device (3, 4) for receiving the data and a sheath (8) enclosing the data memory device (2). The sheath (8) has a spherical, ellipsoid, ovoid and/or rounded convex wall. A flight data memory device (11) has a plurality of flight data memory modules (1), a receptacle for arranging the plurality of flight data memory modules (1) in and/or on an aircraft and an ejector device (12) for mechanically ejecting the flight data memory modules (1). A flight data storage system (10) has a flight data memory device (11), a data-collecting device (16) for collecting data in a flight data system (17) and a data-transmitting device (15) for transmitting the data collected by the data-collecting device (16) to at least one of the flight data memory modules (1).
    Type: Application
    Filed: December 5, 2014
    Publication date: November 3, 2016
    Applicant: Northrop Grumman Litef GMBH
    Inventor: HARALD FISCHER
  • Patent number: 9417267
    Abstract: In an integrated optical circuit, light from a light source is polarized and coupled to a first and second strip waveguide. A waveguide coupling element couples the two optical signals from the two strip waveguides to different polarization modes of an optical fiber line. The optical fiber line is connected to a measuring head, which reflects the optical signal and in which a phase difference between the two optical partial signals is modulated in a magnetic field. In the waveguide coupling element, the reflected signal is split into two optical partial signals having the same polarization and the phase difference between the two partial signals is determined. A phase modulator device provides for closed-loop operation. Compared to fiber-optical concepts, the number of splices is reduced.
    Type: Grant
    Filed: February 8, 2013
    Date of Patent: August 16, 2016
    Assignee: Northrop Grumman Litef GmbH
    Inventors: Georg Dorner, Sven Voigt, Christian Koos, Wolfgang Freude, Juerg Leuthold
  • Publication number: 20160222946
    Abstract: The invention relates to a system for monitoring movements of a structure (1), which system comprises at least one inertial measurement device (5), mounted on said structure, for detecting rotation rates and acceleration values in the earth-fixed inertial system. A central unit (11) determines a monitoring value on the basis of the rotation rates and acceleration values, using a navigation algorithm. The invention further relates to an output unit (12) for outputting the monitoring value.
    Type: Application
    Filed: August 28, 2014
    Publication date: August 4, 2016
    Applicant: NORTHROP GRUMMAN LITEF GMBH
    Inventor: MANFRED KRINGS
  • Patent number: 9356607
    Abstract: A controller unit includes a PI-controller for harmonic command variables. The transfer function of the PI-controller has a conjugate complex pole at a controller angular frequency ?r in the s-plane or a pole at e±j?rT in the z-plane, wherein T is the sampling time of a discrete input signal of the PI-controller and ?r is larger than 0. The controller angular frequency ?r is chosen equal to the resonance angular frequency ?0 of an oscillator. The controller parameters, are, for example determined by pole/zero compensation. The controller unit allows, for example, a broad band control of harmonic oscillators in rotation rate sensors.
    Type: Grant
    Filed: December 15, 2011
    Date of Patent: May 31, 2016
    Assignee: Northrop Grumman Litef GmbH
    Inventors: Günter Spahlinger, Markus Ruf
  • Patent number: 9329412
    Abstract: A digital integrated optical modulator, in particular for a fiber optical signal transmission or measuring device, having two waveguide arms and electrodes that are arranged along both waveguide arms in or on an optical substrate, wherein the arrangements of the electrodes along the two waveguide arms are different from each other.
    Type: Grant
    Filed: August 10, 2011
    Date of Patent: May 3, 2016
    Assignee: Northrop Grumman Litef GmbH
    Inventor: Sven Voigt
  • Publication number: 20150211857
    Abstract: A control device comprises a sensor unit (170), which outputs a measurement signal, which reflects a deviation of an oscillator (190) along a direction of excitation. A controller main unit (200) deduces from the measurement signal and a harmonic set point signal a control signal for an actuator unit such that the actuator unit (180) counteracts a deviation of the deflection of the oscillator (190) from a set amplitude of a harmonic resonance oscillation. A controller extension unit (600) estimates at deactivated actuator unit (180) actual-phase and actual-amplitude of a residual oscillation of the oscillator (190) and synchronizes the harmonic set point signal with the residual oscillation. The residual energy contained in the residual oscillation is used, in order to arrive faster at a defined operation state of the oscillator.
    Type: Application
    Filed: October 15, 2012
    Publication date: July 30, 2015
    Applicant: Northrop Grumman LITEF GmbH
    Inventor: Markus Ruf
  • Patent number: 9052196
    Abstract: A Coriolis gyroscope comprises a mass system that can be excited to perform vibrations parallel to a first axis, whereby a deflection of the mass system due to a Coriolis force along a second axis perpendicular to the first axis is detectable. At least one first correction unit and at least one second correction unit, which each comprise a plurality of stationary correction electrodes and moving correction electrodes whereby the stationary correction electrodes extend in the direction of the first axis and are firmly connected to the substrate by corresponding anchor structures, and the moving correction electrodes are provided as a part of the mass system. A method for reducing the quadrature bias of a Coriolis gyroscope of this type comprises applying at least temporarily constant corrective voltages to the correction units.
    Type: Grant
    Filed: February 1, 2011
    Date of Patent: June 9, 2015
    Assignee: Northrop Grumman LITEF GmbH
    Inventors: Wolfram Geiger, Peter Leinfelder
  • Patent number: 8982356
    Abstract: A fiber-optic interferometer comprising an optical fiber wound to form a fiber coil into which two partial light beams of a first light source can be coupled. The Bragg structure is integrated into the fiber coil. Said Bragg structure comprises an optical fiber having a periodically varying refractive index. In a method for determining physical state parameters in the interior of a fiber coil of a fiber optic interferometer information about physical state parameters in the interior of the fiber coil is obtained on the basis of the reflection wavelength of a Bragg structure comprising an optical fiber having a periodically varying refractive index is integrated into the fiber coil.
    Type: Grant
    Filed: July 17, 2009
    Date of Patent: March 17, 2015
    Assignee: Northrop Grumman LITEF GmbH
    Inventor: Georg Dorner
  • Patent number: 8866058
    Abstract: An optical transceiver comprises a substrate having a temperature control device, a light source, a light-guiding fiber, a detector, optics for collimating the light from the light source, coupling optics for focusing the light beam into the light-guiding fiber, and a beamsplitter which sends one part of the collimated light beam into a wavelength stabilization unit and another part of the collimated light beam into the coupling optics. A wavelength stabilization unit detects and compensates for wavelength drift of the light source. The optical transceiver has a superluminescent diode for its light source and may, for example, be integrated in a fiber-optic gyro.
    Type: Grant
    Filed: July 22, 2010
    Date of Patent: October 21, 2014
    Assignee: Northrop Grumman LITEF GmbH
    Inventor: Sven Voigt
  • Patent number: 8842286
    Abstract: In the case of a fiber-optic Sagnac interferometer, the output of an analog/digital converter and thus output signals processed in a main control circuit as well as a phase resetting signal for a phase modulation encompass a first word width. An input of a digital/analog converter and thus a resetting signal, which acts on the phase modulator, encompasses a second word width, which is smaller than the word width, with which the resetting and modulation signal is computed. A residual value signal comprising a third word width, which can be added to the output signal of the analog/digital converter via an adder, is obtained from the surplus, low-value bits.
    Type: Grant
    Filed: April 20, 2012
    Date of Patent: September 23, 2014
    Assignee: Northrop Grumman LITEF GmbH
    Inventor: Olaf Deppe-Reibold
  • Publication number: 20140268164
    Abstract: A fiber-optic Sagnac interferometer in a rotation rate sensor comprises a multifunctional integrated optical chip (MIOC) with a MIOC transfer function. A digital filter is connected upstream to the multi-functional integrated optical chip, whose filter transfer function corresponds basically to the inverse MIOC transfer function such that the MIOC transfer function is compensated by the filter transfer function. Corresponding coefficients of the filter transfer function may be determined in a main control loop.
    Type: Application
    Filed: March 12, 2014
    Publication date: September 18, 2014
    Applicant: Northrop Grumman LITEF GmbH
    Inventors: Guenter Spahlinger, Olaf Deppe-Reibold
  • Patent number: 8830477
    Abstract: A method for determination of loads in a mechanical structure and/or of damage or states in the mechanical structure which result from the loads in the mechanical structure. Rotations of a part of the mechanical structure caused by loads/damage in the mechanical structure are measured by a fiber optic rotation sensor that is rigidly connected mechanically to the structural part. The loads/damage/states in the mechanical structure are deduced from the measured rotations.
    Type: Grant
    Filed: January 31, 2007
    Date of Patent: September 9, 2014
    Assignee: Northrop Grumman LITEF GmbH
    Inventors: Ulrich Schreiber, Andreas Rasch, John B. Mander, Athol James Carr
  • Publication number: 20130234698
    Abstract: In an integrated optical circuit, light from a light source is polarized and coupled to a first and second strip waveguide. A waveguide coupling element couples the two optical signals from the two strip waveguides to different polarization modes of an optical fiber line. The optical fiber line is connected to a measuring head, which reflects the optical signal and in which a phase difference between the two optical partial signals is modulated in a magnetic field. In the waveguide coupling element, the reflected signal is split into two optical partial signals having the same polarization and the phase difference between the two partial signals is determined. A phase modulator device provides for closed-loop operation. Compared to fiber-optical concepts, the number of splices is reduced.
    Type: Application
    Filed: February 8, 2013
    Publication date: September 12, 2013
    Applicant: Northrop Grumman LITEF GmbH
    Inventors: Georg Dorner, Sven Voigt, Christian Koos, Wofgang Freude, Juerg Leuthold
  • Patent number: 8466748
    Abstract: An amplifier circuit comprises a detector element with signal-dependent output current, a load resistance and an operational amplifier. A terminal of the detector element and the load resistance are electrically connected to an input of the operational amplifier. The load resistance is provided in the form of at least two series-connected part-resistors. A compensation capacitor is in each case connected in parallel with each part-resistor, or a number of series-connected part-compensation capacitors are connected in parallel with each part-resistor. The output of the operational amplifier is connected to two of the compensation capacitors or part-compensation capacitors by a feed capacitor so that the effect of a parasitic capacitance of the load resistance is at least partially compensated for.
    Type: Grant
    Filed: March 23, 2011
    Date of Patent: June 18, 2013
    Assignee: Northrop Grumman LITEF GmbH
    Inventor: Ernst Rau
  • Patent number: 8424382
    Abstract: A microelectromechanical sensor and operating method therefor. The sensor has at least one movable electrode. An electrode arrangement is spaced apart from the movable electrode with a plurality of electrodes that can be driven separately and to which corresponding electrode signals can be applied that can be used to electrostatically set/change the application of force, the spring constant and the read-out factor of the movable electrode. An electrode signal generation unit is connected to the electrode arrangement and can be supplied with a force application signal, a spring constant signal and a read-out factor signal, which define the settings/changes to be brought about with regard to the application of force, spring constant and read-out factor of the movable electrode.
    Type: Grant
    Filed: August 8, 2007
    Date of Patent: April 23, 2013
    Assignee: Northrop Grumman LITEF GmbH
    Inventor: Guenter Spahlinger
  • Patent number: 8365595
    Abstract: A rotation rate sensor comprises a substrate and two structures which move relative to the substrate on a design plane (x-y), with the two moving structures being coupled to form a coupled structure such that the coupled structure has a first oscillation mode with antiphase deflections of the moving structures in a first direction (x) on the design plane (x-y) as excitation mode. The coupled structure has a second oscillation mode as a detection mode which is excited by Coriolis accelerations when the first oscillation mode is excited and on rotation about a sensitive axis (z) of the rotation rate sensor. The sensitive axis is at right angles to the design plane (x-y), and the coupled structure is designed such that, subject to optimal preconditions, it does not have any oscillation mode which can be excited by linear accelerations of the rotation rate sensor in a direction parallel to the second axis.
    Type: Grant
    Filed: March 28, 2008
    Date of Patent: February 5, 2013
    Assignee: Northrop Grumman LITEF GmbH
    Inventors: Wolfram Geiger, Peter Leinfelder, Guenter Spahlinger, Julian Bartholomeyczik