Displacement Patents (Class 324/207.11)
  • Publication number: 20080048652
    Abstract: A position detecting device has a movable unit, and a hold unit that movably holds the movable unit. One of the movable unit and hold unit has a magnetic field generator having an engaged portion and a guide opening. A magnetic field sensor is provided on the other unit of the movable unit and hold unit. The sensor senses the magnetic field so as to detect the position of the movable unit relative to the hold unit. The magnetic field generator is fixed to the first surface after the magnetic field generator is slidingly moved by a rod member inserted into the guide opening and engaged with the engaged portion so as to dispose the magnetic field generator at a predetermined position.
    Type: Application
    Filed: July 12, 2007
    Publication date: February 28, 2008
    Applicant: PENTAX CORPORATION
    Inventor: Masashi MURAKITA
  • Patent number: 7323868
    Abstract: An embodiment of the invention generally relates to a temperature-independent method of determining an engine health parameter, namely stand-off distance, between an eddy current sensor and a conductive element. The method includes receiving a signal from the eddy current sensor and demodulating a waveform from the received signal. The method also includes determining a predetermined set of substantially temperature-independent parameters from the waveform and determining the stand-off distance based on the predetermined set of substantially temperature-independent parameters.
    Type: Grant
    Filed: September 21, 2005
    Date of Patent: January 29, 2008
    Assignee: General Dynamics Advanced Information Systems, Inc.
    Inventors: Victor G. Mishkevich, Douglas R. Browning, Richard T. Gieske
  • Patent number: 7323843
    Abstract: It is possible to determine the types and values of stator and rotor errors in magnetic circuits in a synchronous machine by measuring the induced voltage (ui) for the terminals of measurement loops which can capture an image of the induction in the measurement gap, then by treating said signals.
    Type: Grant
    Filed: February 25, 2004
    Date of Patent: January 29, 2008
    Assignee: Ecole Polytechnique Federale De Lausanne (EPFL)
    Inventors: Xuan Main Tu, Jean-Jacques Simond
  • Patent number: 7319319
    Abstract: There is described a sensor comprising an excitation winding, a signal generator operable to generate an excitation signal and arranged to apply the generated excitation signal to the excitation winding, a sensor winding electromagnetically coupled to the excitation winding and a signal processor operable to process a periodic electric signal generated in the sensor winding when the excitation signal is applied to the excitation winding by the signal generator to determine a value of a sensed parameter. The excitation signal comprises a periodic carrier signal having a first frequency modulated by a periodic modulation signal having a second frequency, the first frequency being greater than the second frequency. In this way, the sensor is well suited to using digital processing techniques both to generate the excitation signal and to process the signal induced in the sensor windings. In an embodiment, the sensor is used to detect the relative position of two members.
    Type: Grant
    Filed: February 22, 2007
    Date of Patent: January 15, 2008
    Assignee: TT Electronics Technology Limited
    Inventors: Ross Peter Jones, Richard Allen Doyle, Mark Anthony Howard, David Alun James, Darran Kreit, Colin Stuart Sills
  • Patent number: 7280937
    Abstract: A shaft comprises a hardened outer metallic layer having a first hardness level with a generally uniform radial depth. A first strip extends in a generally longitudinal direction in the outer metallic layer. The first strip has a second hardness level different from the first hardness level. A second strip in the outer metallic layer has the second hardness level. The first strip and the second strip are spaced apart from each other over at least a longitudinal region. A sensor senses an angular difference between a first magnetic field associated with the first strip and a second magnetic field associated with the second strip. A data processor references an established relationship between a position of the shaft and the angular difference between magnetic fields associated with the first strip and the second strip to detect a position of the shaft with respect to a reference point.
    Type: Grant
    Filed: April 18, 2006
    Date of Patent: October 9, 2007
    Assignee: Deere & Company
    Inventors: Ashley Elwood Greer, James Edward Lenz
  • Patent number: 7276827
    Abstract: A motorized reduction gear intended for functional equipment of a vehicle includes a rotor having with a rotor shaft bearing a commutator, a reduction gearbox containing a gearwheel engaged with a worm belonging to the shaft, and a magnetic ring attached to the commutator and mounted on the shaft to count the number of shaft rotations. The ring can be attached to the commutator in various ways, for example by overmolding the ring on the body such that the ring lies over virtually the entire length of the body. Hooks that retain the electrical connection of the rotor are attached to the magnetic ring. The attachment of the ring directly on the commutator, of which the ring forms an integral part, makes it possible to ensure reliable and lasting retention of the ring.
    Type: Grant
    Filed: January 12, 2001
    Date of Patent: October 2, 2007
    Assignee: Meritor LVS France
    Inventors: Michel Le Hir, Alain Jeusset
  • Publication number: 20070222343
    Abstract: A rotary input apparatus is disclosed. The rotary input apparatus comprising a rotatable wheel, a first magnet joined to a side of the wheel for cooperation with the wheel and magnetized to have alternating N- and S-poles, a detection element positioned to face the first magnet for detecting changes in magnetism of the first magnet, a second magnet positioned to face the first magnet and magnetized to have alternating N- and S-poles in correspondence with the first magnet, a printed circuit board on which are mounted the detection element and the second magnet, a base to which the printed circuit board is secured, and a holder joined to the base and interposed between the wheel and the base to rotatably support the wheel, allows the user to decide whether or not to create click sensations and to regulate the magnitude of the click sensations, where the rotary input apparatus has a simple composition and yet has excellent durability.
    Type: Application
    Filed: October 13, 2006
    Publication date: September 27, 2007
    Applicant: SAMSUNG ELECTRO-MECHANICS CO., LTD.
    Inventor: Eung-Cheon Kang
  • Publication number: 20070182405
    Abstract: The magnetic sensor in the invention includes a detecting section that detects a change of magnetic flux due to a movement of the magnetic movable, comparator circuits constituting a converting section that converts a change of magnetic flux detected by the detecting section into an electric amount, and a D-FF circuit device, in a sensor unit having a power-supplying power terminal VB, a ground terminal GND and an output terminal VOUT. A current control section is provided to change the amount of current flowing through at least one of the power terminal and the ground terminal, correspondingly to a moving direction of the magnetic movable. Thus, a moving direction of the magnetic movable can be determined depending upon the amount of current.
    Type: Application
    Filed: August 23, 2006
    Publication date: August 9, 2007
    Applicant: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Masahiro YOKOTANI, Naoki HIRAOKA
  • Patent number: 7248994
    Abstract: An apparatus and method for determining a linear position from a linear variable differential transformer (LVDT) including a primary coil driven by an excitation signal, and two secondary coils coupled to two correlated signals. The method includes converting the correlated signals to a digital estimate, for each of the correlated signals, and evaluating an amplitude of the correlated signals to determine the linear position. The process of converting the correlated signals comprises comparing the correlated signal to an analog feedback signal to generate a comparison result and incrementally adjusting the digital estimate in response to sampling the comparison result at an estimation frequency.
    Type: Grant
    Filed: January 27, 2006
    Date of Patent: July 24, 2007
    Assignee: Alliant Techsystems Inc.
    Inventor: John A. Stolan
  • Patent number: 7221154
    Abstract: An inductive position sensor for rotary motion includes a transmitter coil and a receiver coil, the receiver coil generating a receiver signal when the transmitter coil is excited by an alternating current source. A moveable coupler element modifies the inductive coupling between the transmitter coil and the receiver coil so that the receiver signal is sensitive to the coupler element position. The ratio between the receiver signal and the reference signal is sensitive to the coupler element position, but substantially insensitive to common mode factors. The angular or positional range of the position sensor can be increased using a plurality of receiver coils.
    Type: Grant
    Filed: April 6, 2006
    Date of Patent: May 22, 2007
    Assignee: KSR International Co.
    Inventor: Joong K. Lee
  • Patent number: 7215112
    Abstract: A non-contact linear absolute position sensor includes a first magnetic encoder having n+1 pole pairs, a second magnetic encoder having n pole pairs and located and aligned with the first magnetic encoder so as to cover a linear distance. The magnetic encoders are affixed to a traveling body. Two pairs of Hall Effect sensors are located near each of the first and second magnetic encoders and are configured to generate linear position signals. A processor is provided to process the linear position signals to generate an output signal indicative of a linear absolute position of the traveling body.
    Type: Grant
    Filed: November 7, 2005
    Date of Patent: May 8, 2007
    Assignee: Delphi Technologies, Inc.
    Inventors: Mario A. Recio, Arquimedes Godoy, Daniel A. Martinez
  • Patent number: 7184914
    Abstract: A sensor signal processor includes a scale having optically or magnetically fine divisions; a detection sensor that moves with respect to the scale and that is provided in association with the divisions of the scale; and a position detecting unit for calculating positional information by using a counter value of digital pulse signals generated from the outputs from the detection sensor and analog signals generated from the outputs from the detection sensor. The sensor signal processor yields the positional information by using both the digital pulse signals and the analog signals.
    Type: Grant
    Filed: July 13, 2006
    Date of Patent: February 27, 2007
    Assignee: Canon Kabushiki Kaisha
    Inventors: Akio Atsuta, Masahiko Igaki
  • Patent number: 7162152
    Abstract: A position detecting device for detecting a position of a movable body which is moved by a drive system having a rotation body includes a magnetic part having an N-pole and an S-pole on a face of the rotation body and a sensor chip having at least a magneto-resistive element. The face of the rotation body is perpendicular to the rotation shaft of the rotation body and the sensor chip is provided so as to face the magnetic part for detecting a variation of magnetic field by the magneto-resistive element when the magnetic part is rotated with the rotation body. A little space is required for mounting the sensor chip having the magneto-resistive element and therefore downsizing can be attained.
    Type: Grant
    Filed: November 18, 2004
    Date of Patent: January 9, 2007
    Assignee: Nidec Sankyo Corporation
    Inventors: Makoto Akabane, Yukio Furuya
  • Patent number: 7148679
    Abstract: A probe (10) for sensing movement of a body of magnetic material comprises a magnetically energisable pole piece (30), a closed loop electrical circuit (20) having a first end (25) which is wound around the pole piece (30) and forms a pole piece coil (25) inductively coupled to the pole piece, the arrangement being such that movement of a body of magnetic material (70) relative to the pole piece (30)induces a current in the closed loop circuit (20), and a second end (45), remote from the pole piece (30), which forms a transformer primary coil. A transformer secondary coil (65) is inductively coupled to the primary coil (45), and terminated by a load resistance and means for measuring an output signal from the secondary coil. The primary (45) and secondary (65) coils form a transformer such that a current in the primary coil induces a voltage across the secondary coil. One or more shorting turns (60) of a conductor are inductively coupled to the primary (45) and secondary (65) coils.
    Type: Grant
    Filed: April 15, 2003
    Date of Patent: December 12, 2006
    Assignee: Weston Aerospace Limited
    Inventor: Kenneth W. Proctor
  • Patent number: 7141985
    Abstract: An electronics package for use with a proximity probe is disclosed that is capable of being calibrated to work with any proximity probe and cable and that is capable of being programmed in the field. The electronic package establishes and measures a plurality of gaps between the proximity probe and a target. An amplifier is operatively coupled to the proximity probe and produces an output which is digitized, linearized and stored. A linear piecewise approximation technique is used to approximate the voltage at the output of the amplifier for gaps that were not measured.
    Type: Grant
    Filed: January 13, 2006
    Date of Patent: November 28, 2006
    Assignee: Vicont, Inc.
    Inventor: George Zusman
  • Patent number: 7138907
    Abstract: A sensor assembly for use in a vehicle seat cushion for detecting the presence of an occupant includes a mat adapted to be installed in the vehicle cushion. The mat includes first mounting structure and a first sensor device attached to the mat. A first member has a second mounting structure adapted to be attached to the first mounting structure for attaching the first member to the mat. A second member is movably mounted relative to the first member about an axis. A second sensor device is mounted in the second member.
    Type: Grant
    Filed: June 26, 2003
    Date of Patent: November 21, 2006
    Assignee: Lear Corporation
    Inventors: Oliver J. Young, John F. Nathan, Christopher Ricard
  • Patent number: 7132948
    Abstract: A system and method for optimally placing radio frequency identification (RFID) antennas. The system varies the placement of RFID tag and interrogator antennas with respect to each other and a stationary object or objects. A signal generator sends a known reference signal to the one or more RFID interrogator antennas. The signal is received by the one or more RFID tag antennas and is displayed upon an oscilloscope, spectrum analyzer or other multipurpose signal measuring device. By this method, the system finds the optimal placement of the antennas with respect to each other and the object or objects.
    Type: Grant
    Filed: January 22, 2005
    Date of Patent: November 7, 2006
    Assignee: Odin Technologies, Inc.
    Inventor: Patrick Joseph Sweeney, II
  • Patent number: 7129698
    Abstract: The present invention is based on the finding that the evaluation of the sensor signals of a position sensor with a mechanical period or, in general terms, the cooperation between position sensors and evaluation units, can be improved by eliminating divergence between the electrically optimal period and the mechanically optimal period. According to the present invention this is achieved in that the position sensor signal, which has a period which depends on the mechanical period of the scale of the position sensor, is translated into a translated signal with a period which corresponds to a second mechanical period, which e.g. has been set to the electrically optimal period, prior to—or for the purpose of—transmitting it to an evaluation unit, whereby not only can transmission errors be minimized and the evaluability improved but a complicated mechanical adjustment of the scale of the position sensor relative to the evaluation unit is avoided.
    Type: Grant
    Filed: June 27, 2002
    Date of Patent: October 31, 2006
    Assignee: Fraunhofer-Gesellschaft zur Foerderung der angewandten Forschung e.v.
    Inventor: Elmar Herzer
  • Patent number: 7123002
    Abstract: The present invention relates to a system for reliably transmitting the position of a control element to an electronic processing unit by way of electric signal lines, wherein the position signal is transmitted by way of several signal channels, and use thereof in a motor vehicle brake system. The present invention further describes a position transmitter for transmitting position signals with a magnetic encoder which is displaceable by a control element in relation to a magnetic transformer, wherein the magnetic transformer(s) along with an integrated electronic signal-conditioning circuit are arranged in an electronic sensor subassembly, as well as a receiving device for receiving a position signal comprising several processing channels for processing the position signals of the position transmitter.
    Type: Grant
    Filed: March 18, 2005
    Date of Patent: October 17, 2006
    Assignee: Continental Teves AG & Co. ohG
    Inventors: Peter Lohberg, Wolfgang Fey, Mario Engelmann, Klaus Rink, Tobias Beckmann
  • Patent number: 7081059
    Abstract: A piston rod position detecting mechanism is proposed which can detect continuously or in a multiple-point manner that the piston rod position has changed due to increase or decrease in the protruding amount of the piston rod due to aging. The protruding amount from a cylinder end wall is detected by a position detecting mechanism comprising a detecting coil housed in a bobbin provided at the cylinder end, a flange portion formed on the piston rod, and a coil spring. Also, an autotensioner and an electromagnetic valve with such a position detector are proposed. Further, a belt tension adjusting device is provided with a detector for detecting the position of a tension pulley which is pivotable with increase or decrease in the belt tension.
    Type: Grant
    Filed: November 4, 2003
    Date of Patent: July 25, 2006
    Assignee: NTN Corporation
    Inventors: Kenichi Iwamoto, Takashi Koike, Kazuyuki Inokuchi, Motoharu Niki
  • Patent number: 7057369
    Abstract: A system for detecting the position of a component drivable by a control element drive, the system comprising: a position sensor housed in a position regulator housing, a movable motion representative to be driven by an actuating motion of the component, via which motion representative of a position motion of the component is transferred into the position regulator housing to the position sensor, which sensor detects the position of the component via the position of the motion representative wherein a drive for transferring and/or redirecting the actuating motion of the component to the motion representative transmits actuating motion forces from the component to the motion representative without contact.
    Type: Grant
    Filed: December 10, 2004
    Date of Patent: June 6, 2006
    Assignee: Samson Aktiengesellschaft
    Inventor: Heinfried Hoffmann
  • Patent number: 7046018
    Abstract: A position sensor is provided comprising a coil (1) and an electric conductor (2) or magnetic (3) both arranged so that the size of their overlapping area (p) is varied as the position of an object to be examined changes, a resistor (6), a capacitor (4), a comparator (5) of an inverse output type, and a timing circuit (50a) arranged for uniformly restraining the period (T) of a continuous oscillating motion, herein a displacement of the object to be examined is detected as a change in the time duration (t) which extends from the leading end of the period (T) to a time when the output of the comparator (5) is turned to a high level as timed with substantially the trailing end of the period (T). The resistance of the resistor (6) is determined so that a change in the time duration (t) remains minimum when the resistance of the resistor (6) is varied and when the temperature is at a predetermined degree.
    Type: Grant
    Filed: April 16, 2003
    Date of Patent: May 16, 2006
    Assignee: Levex Corporation
    Inventors: Seiji Toda, Naomasa Oshie
  • Patent number: 7045996
    Abstract: A method for determining position of a device includes generating at least two, time-varying, magnetic fields using inductive elements, wherein the fields have differing phases. The method further includes detecting a signal modulated on top of the fields, wherein the signal is generated from the device, and determining a position of the device based on a phase difference of the signal from the device and a reference signal.
    Type: Grant
    Filed: January 30, 2003
    Date of Patent: May 16, 2006
    Assignee: Hewlett-Packard Development Company, L.P.
    Inventors: Geoff M. Lyon, Salil Pradhan, Chandrakant Patel
  • Patent number: 7026811
    Abstract: An apparatus for inspecting a metallic post contoured in a single dimension for defects. The apparatus has a clamp having at least one jaw with a surface conforming to the contour to the metallic post. The conforming jaw or jaws also have a plurality of eddy current coils and the probe has at least one sensor configured to sense at least one of position or motion.
    Type: Grant
    Filed: March 19, 2004
    Date of Patent: April 11, 2006
    Assignee: General Electric Company
    Inventors: Robert Martin Roney, Jr., Thomas Francis Murphy
  • Patent number: 7019515
    Abstract: A pulsar ring is provided with a ring-shaped supporting member and a magnetized member formed into a strip shape and secured to a circumferential face of the supporting member so that N-poles and S-poles are arranged alternately with equal pitches. The length of the circumferential face of the supporting member is set so as to correspond to the length of the magnetized member so that the end portions of the magnetized member are butted to each other without any gap with the magnetic property in the butted portion being maintained to have equal pitches. The magnetized member is magnetized by a magnetizing device, and then affixed to the supporting member.
    Type: Grant
    Filed: September 10, 2002
    Date of Patent: March 28, 2006
    Assignee: Koyo Seiko Co., Ltd.
    Inventor: Minoru Sentoku
  • Patent number: 7009360
    Abstract: Disclosed is a method for controlling an SRM (Switched Reluctance Motor) switching angle by an analog encoder system that can perform a precise control of the switching angle of the SRM by comparing an analog sensor signal detected by the analog encoder system with a switching-on/off command signal. During a rotation of an encoder rotor having rotary slits formed at the same intervals on the encoder rotor and continuous contrast patterns formed between the respective rotary slits, analog sensor signals ?a to ?d detected in proportion to the contrast patterns are compared with a switching-on/off command signal controlled by a digital-to-analog (D/A) converter. A switching-on angle ?on is set to a crossing point of the switching-on command signal Von and a slope between the sensor signals ?a and ?o, and a switching-off angle ?off is set to a crossing point of the switching-off command signal Voff and a slope between the sensor signals ?o and ?d.
    Type: Grant
    Filed: December 9, 2004
    Date of Patent: March 7, 2006
    Inventors: Ahn Jin-woo, Park Seong-joon
  • Patent number: 6993443
    Abstract: With a method for determining and tracking a changing, true position and orientation of a magnetic field sensor within a three-dimensional magnetic field space from the values measured by the magnetic field sensor, the magnetic field space is structured in a preceding calibration mode into a three-dimensional grid with equidistant grid points. All values measured by the magnetic field sensor are then stored in a calibration table as calibration positions and calibration orientations allocated to the real positions of the grid points in the magnetic field space. A linear interpolating transformation of the measuring position in the real magnetic field space is executed for the measuring values from the magnetic field sensor by using respectively four calibration positions taken from the calibration table, which span a tetrahedron that encloses the measuring position.
    Type: Grant
    Filed: February 23, 2004
    Date of Patent: January 31, 2006
    Assignee: Rheinmetall Defence Electronics GmbH
    Inventor: Norbert Härle
  • Patent number: 6984954
    Abstract: A strategy to control and diagnose the operation of an electric motor using a sensorless control system augmented by feedback from a position and speed sensor is disclosed. The strategy can improve the robustness of operation and diagnose potential faults in electric motors. The present invention includes a method for diagnosing operation of an electric motor and a method and system for controlling an electric motor. In the diagnostic method, a sensorless system and a sensor based system are checked against each other to determine if either of the systems is faulted. In the control method, the sensor based control system is used when the motor speed is below a predetermined threshold and the sensorless system is used when the motor speed is above the predetermined threshold. The position sensor can be a low resolution position sensor, an engine crankshaft sensor, an engine camshaft sensor, or a transmission sensor.
    Type: Grant
    Filed: April 14, 2004
    Date of Patent: January 10, 2006
    Assignee: Ford Global Technologies, LLC
    Inventors: Franco Leonardi, Henry Heping Huang, John Michael Miller, Michael W. Degner
  • Patent number: 6960973
    Abstract: An angular position sensor employs a pair of magnets that are disposed on a rotating cylinder at opposite ends of a diameter of the cylinder. A hall-effect flux sensor is fixed within the cylinder and offset from a line of geometric and magnetic symmetry between the magnets. The offset sensor detects a linear change in flux of the magnets as the magnets rotate with the cylinder over a predetermined angular distance and thereby determines the angular position of the cylinder. The offset of the sensor is adjusted to reduce the sensing error.
    Type: Grant
    Filed: June 18, 2003
    Date of Patent: November 1, 2005
    Assignee: The Cherry Corporation
    Inventors: Daniel J. Mattson, Peter D. Joseph
  • Patent number: 6960911
    Abstract: A strain sensor includes a sensor section having a magnetic material provided on one surface of a conductor, the magnetic material being formed integrally with the conductor and having a magnetic strain constant with an absolute value larger than 1×10?7, a fixing mechanism which fixes at least a part of the sensor section, an inductor disposed in a surface side of the sensor section which is opposite the surface on which the magnetic material is provided, the inductor being disposed opposite and away from the sensor section, and a detection unit which detects the amount of deformation of the sensor section caused by stress applied thereto on the basis of a change in inductance of the inductor.
    Type: Grant
    Filed: January 29, 2003
    Date of Patent: November 1, 2005
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Tetsuo Inoue
  • Patent number: 6941207
    Abstract: Operates steering angular velocity in first steering angular velocity calculating unit and second steering angular velocity calculating unit, by using steering angle signal from steering angle generating unit, and outputs steering angular velocity by switching them with reference to a certain threshold value of steering angular velocity.
    Type: Grant
    Filed: October 6, 2004
    Date of Patent: September 6, 2005
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Katsunori Matsubara, Makoto Inoue
  • Patent number: 6933846
    Abstract: A displacement sensing system including an oscillator circuit having a characteristic frequency which varies as a function of a magnetic field in the vicinity thereof, an element whose position relative to the oscillator circuit is varied by a displacement, the element being operative to vary the magnetic field in the vicinity of the oscillator circuit as a function of the displacement and circuitry for sensing a change of frequency of the oscillator circuit over time (delta f/delta t) and for providing an output indication when the change in frequency of the oscillator circuit over time exceeds a threshold.
    Type: Grant
    Filed: April 18, 2001
    Date of Patent: August 23, 2005
    Assignee: Visonic Ltd.
    Inventors: Mark Moldavsky, Boris Zhevelev
  • Patent number: 6919720
    Abstract: A detector to determine the peak-to-peak value of a signal is presented. The detector includes a first circuit to provide a tracking signal that tracks a positive slope of the signal during a first time interval and a negative slope of the signal during a second time interval. The detector further includes a second circuit configured to produce values associated with the tracking signal provided during one of the first and second time intervals, where one of the values is indicative of the peak-to-peak value of the signal.
    Type: Grant
    Filed: January 21, 2003
    Date of Patent: July 19, 2005
    Assignee: Allegro Microsystems, Inc.
    Inventors: Ravi Vig, Jay M. Towne, Michael C. Doogue
  • Patent number: 6914438
    Abstract: A position sensor is provided comprising a coil (1) and an electric conductor (2) or magnetic (3) both arranged so that the size of their overlapping area (p) is varied as the position of an object to be examined changes, a resistor (6), a capacitor (4), a comparator (5) of an inverse output type, and a timing circuit (50a) arranged for uniformly restraining the period (T) of a continuous oscillating motion, herein a displacement of the object to be examined is detected as a change in the time duration (t) which extends from the leading end of the period (T) to a time when the output of the comparator (5) is turned to a high level as timed with substantially the trailing end of the period (T). The resistance of the resistor (6) is determined so that a change in the time duration (t) remains minimum when the resistance of the resistor (6) is varied and when the temperature is at a predetermined degree.
    Type: Grant
    Filed: April 16, 2003
    Date of Patent: July 5, 2005
    Assignee: Levex Corporation
    Inventors: Seiji Toda, Naomasa Oshie
  • Patent number: 6895997
    Abstract: System determines the position of a control element of an electrically driven actuator. The actuator may be switched on by a controlled switch when a lower threshold value is reached and may be switched off when an upper threshold value is reached. An on-period and an off-period are determined as a function of the lower threshold value, the upper threshold value, and the electric switching behavior of the actuator depending on the position of the control element. From the on-period and the off-period, the position of the control element are determined from a comparison of the quotient of the on-period or off-period and the sum of the on-period and off-period, and from a comparison of the sum of the on-period and the off-period with corresponding stored reference data. The system includes accompanying circuitry for application of the process, and an accompanying device, in particular a hydraulic valve.
    Type: Grant
    Filed: February 19, 2003
    Date of Patent: May 24, 2005
    Assignee: Hydac Electronic GmbH
    Inventors: Wenmin Qu, Horst Peter Mannebach, Joachim Morsch
  • Patent number: 6885310
    Abstract: Two A.C. output signals amplitude-modulated in accordance with two function values (sine and cosine) differing from each other in correspondence to a position-to-be-detected are received from a position sensor such as a resolver. By performing an addition or subtraction between a signal derived by shifting the electric phase of one of the received A.C. output signals by a predetermined angle, and the other received signal, two electric A.C. signals (sin(?t±d+?), sin((?t±d??)) are electrically synthesized which have electric phase angles (?) corresponding to the position-to-be-detected and are phase-shifted in opposite directions. “±d” here represents phase variation error caused by factors, other than the position-to-be-detected, such as temperature change. In the synthesized two signals, the phase variation errors (±d) appear in the same direction, while the phase differences (?) corresponding to the position are shifted in opposite, positive and negative, directions.
    Type: Grant
    Filed: March 3, 2003
    Date of Patent: April 26, 2005
    Inventors: Atsutoshi Goto, Yasuhiro Yuasa, Shuichi Tanaka, Nobuyuki Akatsu, Kazuya Sakamoto, Hiroshi Sakamoto, Akio Yamamoto
  • Patent number: 6864679
    Abstract: A rotary manipulation type input device obtains a specified output by detecting intensity changes of magnetic field due to rotation of an operating element by a detecting element disposed on a substrate beneath a base, using a ring-shaped magnet disposed at the lower side of the operating element disposed rotatably on the base. By rotary manipulation of the operating element, an attractive and repulsive force is generated between the ring-shaped magnetic and the magnetic disposed on the base, so that an operation contact click-feeling is obtained, and therefore the rotary click-feeling and signal output can be synchronized easily, and deterioration of rotary click-feeling is very rare.
    Type: Grant
    Filed: March 17, 2003
    Date of Patent: March 8, 2005
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Shigeru Yokoji, Tamotsu Yamamoto
  • Patent number: 6850054
    Abstract: A device and a method for non-contacting sensing of the rotational state of a rotor (10). The rotor has a surface divided into an electrically conductive part (1e) and a nonconductive part (1f). Three electric coils (2a, 2b, 2c) are each included in a respective parallel resonant circuit and are applied close to and with their longitudinal axes oriented towards the rotational path of the electrically conductive part of the rotor. The resonant oscillations are damped depending on the rotational position of the rotor. The rotational state is evaluated with an electronic circuit. In a liquid-flow meter, the coils may be applied in the dry part of the meter.
    Type: Grant
    Filed: July 2, 2001
    Date of Patent: February 1, 2005
    Assignee: Elster Messtechnik GmbH
    Inventors: Tord Kjellin, Staffan Ralberg
  • Patent number: 6836745
    Abstract: A method for determining the position of a sensor element which is used to measure a magnetic alternating field emitted by at least one generator unit. The sensor element receives a signal. Interference fields, which are the fields arising due to eddy currents generated in electrically conductive objects, are calculated. The eddy currents are calculated based on the alternating field. The position can be corrected based on the signal received in the sensor element.
    Type: Grant
    Filed: April 14, 2003
    Date of Patent: December 28, 2004
    Assignee: Northern Digital Inc.
    Inventors: Paul G. Seiler, Ralph K. Muench, Stefan R. Kirsch
  • Patent number: 6812695
    Abstract: A device for detecting one or more parameters of a rotary member angular displacement, includes: and instrumented roller bearing (1) provided with a non-rotating part including a non-rotating ring (2) and a sensor block (8), a rotating part including a rotating ring (2) and a coding ring (15) mounted opposite the sensor block (8) and at least a row of rolling elements (4); and elements for processing signals transmitted by the sensor block. The sensor block (8) comprises at least two sensing elements (9, 10) co-operating with the single coding ring, signals transmitted independently by each sensing element corresponding to the same parameter of angular displacement, so as to supply to the processing elements a redundant information on the parameter of angular displacement.
    Type: Grant
    Filed: July 7, 2003
    Date of Patent: November 2, 2004
    Assignee: SKF France
    Inventor: Franck Landrieve
  • Patent number: 6798194
    Abstract: A digital eddy current proximity system including a digital impedance measuring device for digitally measuring the proximity probes impedance correlative to displacement motion and position of a metallic target object being monitored. The system further including a cable-length calibration method, an automatic material identification and calibration method, a material insensitive method, an inductive ratio method and advanced sensing characteristics.
    Type: Grant
    Filed: May 30, 2003
    Date of Patent: September 28, 2004
    Assignee: Bently Nevada, LLC
    Inventor: Richard D. Slates
  • Patent number: 6784796
    Abstract: One or more magnets are placed in a container (preferably on objects inside the container) and the magnetic field strength and vector direction are measured with a magnetometer from at least one location near the container to provide the container with a magnetic vector field tag and seal. The location(s) of the magnetometer relative to the container are also noted. If the position of any magnet inside the container changes, then the measured vector fields at the these locations also change, indicating that the tag has been removed, the seal has broken, and therefore that the container and objects inside may have been tampered with. A hollow wheel with magnets inside may also provide a similar magnetic vector field tag and seal. As the wheel turns, the magnets tumble randomly inside, removing the tag and breaking the seal.
    Type: Grant
    Filed: November 6, 2001
    Date of Patent: August 31, 2004
    Assignee: The Regents of the University of Califronia
    Inventors: Roger G. Johnston, Anthony R. E. Garcia
  • Patent number: 6772101
    Abstract: Angle data ranging from 0° to 360° obtained by performing polar conversion with respect to a periodic signal are input to a low pass filter having: a phase accumulator for outputting smoothed angle data; a phase comparator for obtaining a phase error between the angle data and the smoothed angle data; a first amplifier for amplifying the phase error; a second amplifier for further amplifying the phase error; an integrator for integrating the phase error PE amplified by the second amplifier to obtain a velocity error; and an adder for adding the phase error amplified by the first amplifier and the velocity error to determine a control voltage. The phase accumulator controls the frequency of the smoothed angle data so that the phase error is zero based on the control voltage to remove a high frequency component in the angle data.
    Type: Grant
    Filed: August 28, 2000
    Date of Patent: August 3, 2004
    Assignee: Sony Precision Technology Inc.
    Inventors: Masato Tanaka, Shigeru Ishimoto, Toyohiko Matsuda, Katsumi Kitamura
  • Publication number: 20040129094
    Abstract: The invention relates to the field of micromovement measuring and can be used for recording creeping and dynamic infraprocesses both of natural and artificial origin, for example, seismic processes or infrasound and gravitation waves. The object of the invention is to raise sensitivity of measuring in a wide dynamic range. The micromovement measuring device consists of measuring element (2) and sensitive element (1), membrane (10), signal conditioner (6), the output of which is connected to the winding og the fixing electromagnet (4). According to the invention, the device is additionally provided with the pulling electromagnet (5), which interacts with the measuring element (2), the winding og the pulling electromagnet being connected to the second inverse output of the signal conditioner (6). The pulling electromagnet shall be preferably located on the membrane (10) that increases the range of the measurable movements.
    Type: Application
    Filed: March 1, 2004
    Publication date: July 8, 2004
    Inventors: Leonids Bekers, Bonifatijs Lubgins, Jehezkelis Finkelshteins, Juris Nurovs, Alexandra Piorunskis
  • Patent number: 6756759
    Abstract: A current target angle stored in a target angle register is subtracted from the immediately preceding target angle stored in a register by a subtracting device. As a result, the length (amount) and direction between the immediately preceding target angle to the current angle are generated. With the generated length and direction, a model acceleration generating circuit generates model acceleration data. With a count value of a current velocity detecting counter and a velocity data sequence that is output from a model velocity generating circuit, velocity error data is generated. With a count value of a current position detecting counter and a position data sequence that is output from a model position generating circuit, position error data is generated. The model acceleration data, the velocity error data, and the position error data are added by an adding device. The added result is supplied to a driver. The driver outputs a current that drives a pan motor.
    Type: Grant
    Filed: July 3, 2002
    Date of Patent: June 29, 2004
    Assignee: Sony Corporation
    Inventor: Noriyuki Yamashita
  • Patent number: 6753783
    Abstract: A patient position monitoring apparatus and method includes an article configured to be worn by a patient. The article includes a plurality of resonators with each resonator responsive to a wireless excitation signal for causing the unique change in the excitation signal or for outputting a unique wireless response signal. The resonators are stimulated with a first wireless excitation signal when the article is being worn by a patient. The unique change in the excitation signal and /or the unique response signal of each resonator responding to the first excitation signal is determined. From the thus detected response, a signal strength of the unique change in the excitation signal and/or the unique response signal for each responding resonator is determined. From the thus determined signal strengths, the relative locations of the responding resonators with respect to each other can be determined.
    Type: Grant
    Filed: April 1, 2002
    Date of Patent: June 22, 2004
    Assignee: AugmenTech, Inc.
    Inventors: Mark B. Friedman, Randall W. Casciola
  • Publication number: 20040116803
    Abstract: A method and apparatus for electromagnetic navigation of a surgical probe near a metal object. The electromagnetic navigation system includes a transmitter coil array and a shield. The transmitter coil array has a plurality of transmitter coils and is operable to generate the electromagnetic field to navigate the probe. The shield is positioned adjacent the metal object and is operable to shield the metal object from the electromagnetic field generated by the transmitter coil array, such that the shield substantially reduces distortion of the electromagnetic field by the metal object.
    Type: Application
    Filed: January 9, 2004
    Publication date: June 17, 2004
    Inventors: Bradley Jascob, David Simon, Paul Kessman, Aaron Smith
  • Patent number: 6750626
    Abstract: A strategy to control and diagnose the operation of an electric motor using a sensorless control system augmented by feedback from a position and speed sensor is disclosed. The strategy can improve the robustness of operation and diagnose potential faults in electric motors. The present invention includes a method for diagnosing operation of an electric motor and a method and system for controlling an electric motor. In the diagnostic method, a sensorless system and a sensor based system are checked against each other to determine if either of the systems is faulted. In the control method, the sensor based control system is used when the motor speed is below a predetermined threshold and the sensorless system is used when the motor speed is above the predetermined threshold. The position sensor can be a low resolution position sensor, an engine crankshaft sensor, an engine camshaft sensor, or a transmission sensor.
    Type: Grant
    Filed: September 11, 2002
    Date of Patent: June 15, 2004
    Assignee: Ford Global Technologies, LLC
    Inventors: Franco Leonardi, Henry Heping Huang, John Michael Miller, Michael W. Degner
  • Patent number: 6750784
    Abstract: A rotary position transducer with a cosine and sine attenuating voltage wave output has the substantially linear portions segmented and pieced together from a predetermined set of conditions to form a continuously linearly varying voltage output.
    Type: Grant
    Filed: November 20, 2001
    Date of Patent: June 15, 2004
    Assignee: Eaton Corporation
    Inventor: Peter M. Jacobsen
  • Patent number: 6727688
    Abstract: A digital eddy current proximity system including a digital impedance measuring device for digitally measuring the proximity probes impedance correlative to displacement motion and position of a metallic target object being monitored. The system further including a cable-length calibration method, an automatic material identification and calibration method, a material insensitive method, an inductive ratio method and advanced sensing characteristics.
    Type: Grant
    Filed: May 29, 2003
    Date of Patent: April 27, 2004
    Assignee: Bently Nevada, LLC
    Inventor: Richard D. Slates