Angular Rate Using Gyroscopic Or Coriolis Effect Patents (Class 73/504.02)
  • Patent number: 6470747
    Abstract: This invention provides a dynamical quantity sensor having a novel structure, wherein first beams 3, 4, 5, 6 are extended from side walls of a recess 2 of a substrate 1, and an intermediate support member 7 is disposed on the first beams 3, 4, 5, 6. Second beams 8, 9, 10, 11 extending in a direction crossing substantially perpendicularly the first beams 3, 4, 5, 6 are disposed on the intermediate support member 7, and a weight 12 is disposed on the second beams 8, 9, 10, 11. Opposing electrodes 17 and 19 and opposing electrodes 18 and 20 are used as electrodes for excitation, and opposing electrodes 13 and 15 and opposing electrodes 14 and 16 are used as electrodes for detecting an angular velocity. The movement of the weight 12 resulting from the application of the angular velocity is detected.
    Type: Grant
    Filed: July 17, 2000
    Date of Patent: October 29, 2002
    Assignee: Denso Corporation
    Inventor: Masahito Mizukoshi
  • Patent number: 6467345
    Abstract: A method for operating a monolithic, integrated, micromachined structure that includes a reference member and one or more dynamic members. Each dynamic member is supported from the reference member, either directly or indirectly, by torsion hinges. Supported in this way, each dynamic member exhibits a plurality of vibrational modes. Preferably, the structure is micromachined to establishes specified relationships between various pairs of vibrational modes. The method also includes applying force to each dynamic member that urges the member to rotate out of a rest position to a fixed particular angle.
    Type: Grant
    Filed: March 3, 2000
    Date of Patent: October 22, 2002
    Assignee: XROS, Inc.
    Inventors: Armand P. Neukermans, Timothy G. Slater
  • Patent number: 6467346
    Abstract: An electrical interface (20) for a Coriolis sensor (10, 11, 13) having an independent, non-zero bias voltage Vb and a plurality of transresistance amplifiers that are referenced to ground. The electrical interface (20) may be used for both a cloverleaf microgyroscope (10, 11) and a hemispherical resonator gyroscope (13). The electrical interface (20) of the present invention reduces the complexity of the control electronics (50) required to control the Coriolis sensor (10, 11, 13) and allows a combination of analog and digital electronics thereby reducing the cost of the Coriolis sensor (10, 11, 13) and its associated control electronics (50).
    Type: Grant
    Filed: June 14, 2000
    Date of Patent: October 22, 2002
    Assignees: Hughes Electronics Corporation, California Institute of Technology
    Inventors: A. Dorian Challoner, Roman C. Gutierrez
  • Publication number: 20020112538
    Abstract: A micromechanical component is described, in particular an acceleration sensor or a rotational speed sensor having a seismic mass device which is flexibly mounted using at least one double U spring and can be deflected in at least one direction by an external acceleration. At least one nap stop is provided to limit the deflection of the double U spring.
    Type: Application
    Filed: October 19, 2001
    Publication date: August 22, 2002
    Inventors: Stefan Pinter, Frank Fischer, Arnold Rump
  • Patent number: 6405594
    Abstract: A microgyroscope has a baseplate made of the same material as the rest of the microgyroscope. The baseplate is a silicon baseplate having a heavily p-doped epilayer covered by a thick dielectric film and metal electrodes. The metal electrodes are isolated from the ground plane by the dielectric. This provides very low parasitic capacitive coupling between the electrodes. The thick dielectric reduces the capacitance between the electrodes and the ground plane.
    Type: Grant
    Filed: July 6, 2000
    Date of Patent: June 18, 2002
    Assignee: California Institute of Technology
    Inventors: Tony K. Tang, Roman C. Gutierrez
  • Publication number: 20020066317
    Abstract: Yaw rate sensors are provided, the use of which permits quantitative measurement of yaw rate. The yaw rate sensor comprises at least a base, a first suspension and a second suspension with a proof mass supported between the two suspensions, which together form a resonator. The first suspension has a pair of thin-wire driving electrodes double side patterned on the surfaces. When a driving voltage is applied to the driving electrodes, it imposes an electric field to piezoelectrically induce a driving resonance. When the sensor is rotated around its sensing axis, the resonator will be forced to generate a sensing resonance out of the driving resonance plane to compensate the change in the linear momentum which must be conserved. The piezoelectric charge signal generated by the sensing resonance on the sensing electrodes which are double side patterned on the surfaces of the second suspension is used to detect the yaw rate. Specifically, the amplitude of the sensing resonance is in proportion to the yaw rate.
    Type: Application
    Filed: December 6, 2000
    Publication date: June 6, 2002
    Inventor: Gang Lin
  • Patent number: 6392220
    Abstract: A monolithically fabricated micromachined structure (52) couples a reference frame (56) to a dynamic plate (58) or second frame for rotation of the plate (58) or second frame with respect to the reference frame (56). Performance of torsional oscillators or scanners (52) benefits greatly by coupling the frame (56) to the plate (58) or second frame with torsional flexure hinges (56) rather than torsion bars (54). Appendages (122), tethers (142) or an improved drive circuit enhance electrostatic drive stability of torsional oscillators (52). Wide and thin torsional flexure hinges (96) and isotopically pure silicon enhance thermal conductivity between the plate (58) and the frame (56). Dampening material bridging slots (232) adjacent to torsional flexure hinges (96) drastically reduce the dynamic member's Q. A widened section (252) of narrow torsional flexure hinges (96) permit inclusion of a torsion sensor (108). A dynamic member (58) that includes an actuator portion (302) performs light beam switching.
    Type: Grant
    Filed: September 2, 1999
    Date of Patent: May 21, 2002
    Assignee: XROS, Inc.
    Inventors: Timothy G. Slater, Armand P. Neukermans
  • Patent number: 6386032
    Abstract: A micromechanical, dithered device comprising a substrate, a movable mass connected to the substrate by a suspension, a position sensor, a dither signal generator, a dither force transducer connected between the substrate and the movable mass, the input of the dither force transducer being connected to the output of the dither signal generator and a calculator taking as inputs at least the position sensor output and the dither signal generator output. In one embodiment of the invention, the dithered device includes an electrostatic force transducer for applying feedback. In this embodiment, dither force may be directly applied to the mechanical proof-mass utilizing electrostatic structures similar to electrostatic structures used for feedback. The electrostatic dithering structures provide good matching between the feedback and dither electrodes, enabling the use of simple logic for subtraction of the dither signal from the accelerometer output.
    Type: Grant
    Filed: August 1, 2000
    Date of Patent: May 14, 2002
    Assignee: Analog Devices IMI, Inc.
    Inventors: Mark A. Lemkin, Allen W. Roessig, Thor Juneau, William A. Clark
  • Publication number: 20020046602
    Abstract: A micromachined gyroscope has first and second coplanar bodies suspended over a substrate and movable in their plane relative to the substrate. The first body is dithered along a dither axis and is movable relative to the second body on the dither axis, but is rigidly connected for movement along an axis transverse to the dither axis. The second body is anchored so that it is substantially inhibited from moving along the dither axis, but can move with the first body along the transverse axis. The gyro has stop members and an anti-levitation system for preventing failure.
    Type: Application
    Filed: December 17, 2001
    Publication date: April 25, 2002
    Inventors: John A. Geen, Donald W. Carow
  • Publication number: 20020046603
    Abstract: A micromachined gyroscope has first and second coplanar bodies suspended over a substrate and movable in their plane relative to the substrate. The first body is dithered along a dither axis and is movable relative to the second body on the dither axis, but is rigidly connected for movement along an axis transverse to the dither axis. The second body is anchored so that it is substantially inhibited from moving along the dither axis, but can move with the first body along the transverse axis. The gyro has stop members and an anti-levitation system for preventing failure.
    Type: Application
    Filed: December 17, 2001
    Publication date: April 25, 2002
    Inventors: John A. Geen, Donald W. Carow
  • Publication number: 20020046605
    Abstract: A micromachined gyroscope has first and second coplanar bodies suspended over a substrate and movable in their plane relative to the substrate. The first body is dithered along a dither axis and is movable relative to the second body on the dither axis, but is rigidly connected for movement along an axis transverse to the dither axis. The second body is anchored so that it is substantially inhibited from moving along the dither axis, but can move with the first body along the transverse axis. The gyro has stop members and an anti-levitation system for preventing failure.
    Type: Application
    Filed: December 17, 2001
    Publication date: April 25, 2002
    Inventors: John A. Geen, Donald W. Carow
  • Patent number: 6366387
    Abstract: A depixelizer for enhancing an image generated by a spatial light modulator having an array of pixels. The depixelizer comprising a translatable stage having the spatial light modulator attached thereto. The stage being moveable in a first axis of motion and a second axis of motion. The movement of the stage in at least one axis oscillates the spatial light modulator and enhances the image generated thereby.
    Type: Grant
    Filed: May 11, 2000
    Date of Patent: April 2, 2002
    Inventor: Stephen S. Wilson
  • Publication number: 20020020218
    Abstract: In order to provide a vibrating gyroscope in which variations in the angular-velocity detection sensitivity are not likely to occur even when sharp temperature changes occur, a vibrator for a vibrating gyroscope includes, on one main surface, a first detection electrode and a second detection electrode, which output a signal containing an angular-velocity signal, wherein a groove having a predetermined depth is provided between the first detection electrode and the second detection electrode. As for a vibrator for a vibrating gyroscope of the present invention, since the difference between the resonance frequency and the anti-resonance frequency in a bending vibration mode in the driving direction becomes closer to the difference between the resonance frequency and the anti-resonance frequency in a bending vibration mode in the detection direction, variations in the angular-velocity detection sensitivity are not likely to occur even when sharp temperature changes are given.
    Type: Application
    Filed: June 14, 2001
    Publication date: February 21, 2002
    Applicant: Murata Manufacturing Co., Ltd.
    Inventors: Nobuyuki Ishitoko, Masato Koike
  • Publication number: 20020017133
    Abstract: A micromachined single-crystalline silicon micro-gyroscope comprising oxide/polysilicon/metal triple layer for electrical isolation is disclosed. The isolation method includes forming the triple layer composed of an insulation layer formed over an exposed surface of the silicon microstructure, a conductive layer formed over the entire insulation layer, and a metal layer formed over a top portion of the microstructure; and partially etching the conductive layer to form electrical isolation between parts of the microstructure. The method does not require a separate photolithography process for isolation, and can be effectively applied to microstructures having high aspect ratios and narrow trenches. Also disclosed are micro-gyroscope comprising a new type of spring which has a node with a hole in the middle of spring to reduce the release etch time for spring.
    Type: Application
    Filed: July 11, 2001
    Publication date: February 14, 2002
    Inventor: Dong-il Cho
  • Publication number: 20020017132
    Abstract: A method of fabricating a micro-mechanical sensor (101) comprising the steps for forming an insulating layer (6) onto the surface of a first wafer (4) bonding a second wafer (2) to the insulating layer (6), patterning and subsequently etching either the first (4) or second wafer (6) such that channels (18,20) are created in either the first (2) or second (4) wafer terminating adjacent the insulating layer (6) and etching the insulating layer (6) to remove portions of the insulating layer (6) below the etched wafer such that those portions of the etched wafer below a predetermined cross section, suspended portions (22), become substantially freely suspended above the un-etched wafer. This method uses Silicon on Insulator technology. Also disclosed is a micro-mechanical gyroscope structure (101) allowing an anisotropic silicon to be used to fabricate a sensor functioning as if fabricated from isotropic silicon.
    Type: Application
    Filed: July 5, 2001
    Publication date: February 14, 2002
    Applicant: The Secretary of State for Defence
    Inventors: Mark E. McNie, Vishal Nayar
  • Publication number: 20020017134
    Abstract: A sensor device has a sensing layer and an auxiliary layer for supporting the sensing layer, the two layers being superposed on each other in a laminar form. The sensing layer has a vibratory body displaceable in a direction parallel to a junction surface between the two layers. The auxiliary layer is affixed to the sensing layer and a recess or through-hole of a larger area than that of the vibratory body is formed in the auxiliary layer at a part thereof confronting the vibratory body.
    Type: Application
    Filed: October 5, 2001
    Publication date: February 14, 2002
    Applicant: Hitachi, Ltd.
    Inventors: Kohei Sakurai, Masahiro Komachiya, Masahiro Matsumoto, Seikou Suzuki
  • Patent number: 6321598
    Abstract: An angular velocity sensor device includes drive oscillators oscillated by driving in drive direction a0, and detecting oscillators connected to the drive oscillators and oscillated in detecting directions a1, a2 by a Coriolis force, which is generated by an angular velocity in a direction K. The directions a1, a2 respectively make an angle &thgr; with the direction K. Detection electrodes are provided for the detecting oscillators, and produce output signals. A signal caused by an inertia force and a signal caused by the Coriolis force are obtained from the output signals, and the angular velocity is determined by the two signals.
    Type: Grant
    Filed: March 9, 2000
    Date of Patent: November 27, 2001
    Assignee: Denso Corporation
    Inventors: Takao Iwaki, Nobuyuki Ohya, Hiroaki Ito
  • Patent number: 6321599
    Abstract: A vibration gyro sensor is constructed as follows. Namely, a detecting piezoelectric/electrostrictive element 12, which detects displacement generated in a direction perpendicular to a direction of vibration of a vibrator 2 when the vibrator is rotated, is provided on a detecting section. The detecting section is constructed by an integrated fired product made of ceramics together with the vibrator 2 and a support base 4. The detecting section is constructed by a first plate-shaped section 6 which is more thin-walled than the vibrator 2 and which has its principal surface extending in the direction of vibration. The piezoelectric/electrostrictive element 12 is formed in an integrated manner on the first plate-shaped section 6 in accordance with a film formation method.
    Type: Grant
    Filed: March 19, 2001
    Date of Patent: November 27, 2001
    Assignee: NGK Insulators, Ltd.
    Inventors: Yukihisa Takeuchi, Masahiko Namerikawa, Kazuyoshi Shibata, Takao Ohnishi
  • Publication number: 20010042403
    Abstract: A structure and arrangement for improving the accuracy and efficiency of an angular rate sensing gyroscope is herein disclosed. Voltage pick-off conductors are applied to an area of the surface of a resonating element of an angular rate sensing gyroscope that is subject to substantially zero stress when the gyroscope is rotationally stationary. Actuator conductors are similarly applied to a resonating element at a location bounded by areas of the resonating element subject to substantially uniform levels of stress when the gyroscope is rotationally stationary. A method for improving the voltage response of a piezoelectric resonating element is also disclosed.
    Type: Application
    Filed: June 13, 2001
    Publication date: November 22, 2001
    Inventor: William S. Watson
  • Publication number: 20010039834
    Abstract: Disclosed is a method of correcting quadrature error in a dynamically decoupled micro-gyro (100, 200) having a drive mass (110, 210) that is vibrated relative to a drive axis (Y, Z) and a sense mass (111, 211) that responds to the drive mass (110, 210) in the presence of an angular rate and associated coriolis force by vibrating relative to a sense axis (X, Y). The method includes the steps of providing a first static force element (121, 221) for applying a first steady-state force to a first region of the drive mass (110, 210); providing a second static force element (122, 222) for applying a second steady-state force to a second region of the drive mass (210), and applying a corrective steady-state force to the drive mass (110, 210) with the first and second static force elements (121, 122; 221, 222), the corrective steady-state force making the drive axis (Y, Z) of the drive mass (110, 210) orthogonal to the sense axis (X, Y) of the sense mass (111, 211).
    Type: Application
    Filed: March 19, 2001
    Publication date: November 15, 2001
    Inventor: Ying W. Hsu
  • Publication number: 20010037682
    Abstract: A vibrator includes: a vibrating body; a driving unit for causing the vibrating body to vibrate in a predetermined vibrating direction; and a driving monitoring unit for detecting vibration displacement in a driving direction of the vibrating body. Stabilization of vibration in the driving direction of the vibrating body is achieved by applying positive feedback control to the driving unit based on the state of the vibration displacement in the driving direction of the vibrating body detected by this driving monitoring unit. The driving monitoring unit is constructed and arranged so as to be provided in a barycentric region of the vibrating body to detect the vibration displacement in the driving direction of the barycentric region of the vibrating body.
    Type: Application
    Filed: May 1, 2001
    Publication date: November 8, 2001
    Applicant: Murata Manufacturing Co., Ltd.
    Inventors: Yoshihiro Konaka, Takahiro Oguchi, Teruhisa Shibahara
  • Publication number: 20010029784
    Abstract: The angular speed sensor device includes a drive frame 11 and a detecting frame 12 which are supported on a silicon substrate 10 in a floating mode. The drive frame 11 and the detecting frame 12 are provided with an angular speed about the z-axis when the drive frame 11 and the detecting frame 12 are driven to vibrate in the x-direction, the resulting Corliolis force causing the detecting frame 12 to oscillate in the y-direction. Such a y-direction oscillation of the detecting frame 12 is detected as a displacement signal. On the basis of the displacement signal, the applied angular speed is calculated. The angular speed sensor device includes detecting electrodes 16a and 16b which drive the detecting frame 12 to vibrate in the y-direction when a drive signal is fed to each of the detecting electrodes 16a and 16b which changes the electrostatic capacitance between the detecting frame 12 and each of the detecting electrodes 16a and 16b.
    Type: Application
    Filed: March 19, 2001
    Publication date: October 18, 2001
    Inventors: Hideya Kurachi, Manabu Kato
  • Patent number: 6301963
    Abstract: A microgyroscope is disclosed, in which an oscillating mass is oscillated by dividing it into three parts, and thus, the forces transmitted from external oscillations are minimized, thereby minimizing the influence of the external oscillations. The microgyroscope includes an inner mass part 110 excitedly installed within an outer frame 120 across beam elastic bodies 130. A plurality of combs 150 are formed on the inner mass part 110, the combs 150 extending in the y axis direction. A plurality of sensing electrodes 170 are disposed between the plurality of the combs 150, the sensing electrode being formed integrally with an electrode supporting part 160. The inner mass part 110 is connected through elastic bodies to outer mass parts 210 and 210′. In this manner, the influence of external oscillations can be minimized, and the friction loss of the supporting part can also be minimized, thereby improving the resolving power of the microgyroscope.
    Type: Grant
    Filed: December 30, 1999
    Date of Patent: October 16, 2001
    Assignee: Samsung Electro-Mechanics Co., Ltd
    Inventor: Kyu-Yeon Park
  • Patent number: 6293148
    Abstract: The present invention is a motion sensor apparatus for use as a general mechanical amplifier, a gyroscope, or other resonant sensor such as an accelerometer. In accordance with the invention, the motion sensor apparatus includes a primary mass and a primary flexure structure. The primary flexure structure supports the primary mass to experience driven motion against a bias of the primary flexure structure. The apparatus further includes a secondary mass which is less massive than the primary mass. A secondary flexure structure interconnects the secondary mass with the primary mass, and supports the secondary mass to experience sensing motion relative to the primary mass against a bias of the secondary flexure structure. The stiffness ratio between the primary and secondary flexure structures is equal to the mass ratio between the primary and secondary masses.
    Type: Grant
    Filed: December 2, 1999
    Date of Patent: September 25, 2001
    Assignee: Institute of Microelectronics
    Inventors: Zhe Wang, Uppili Sridhar, Rong Ming Lin, Mong King Lim
  • Publication number: 20010015101
    Abstract: An angular velocity sensor has a weight portion that can be drive-oscillated in a driving direction and be oscillated in a detecting direction when an angular velocity is applied, and unnecessary oscillation suppressing electrodes that can generate an electrostatic force to be applied to the weight portion in the detecting direction. The electrostatic force prevents the weight portion from being drive-oscillated in a direction other than the driving direction. As a result, unnecessary oscillation of the weight portion can be prevented even when the angular velocity sensor has a processing error.
    Type: Application
    Filed: February 8, 2001
    Publication date: August 23, 2001
    Inventors: Takao Iwaki, Kazuhiko Kano, Toshiki Isogai
  • Patent number: 6269697
    Abstract: Upper electrodes (A1 to A5) are disposed on an upper surface of a disk-shaped piezoelectric element (10). On a lower surface of the piezoelectric element (10), an annular groove to surround origin O is formed at position corresponding to the upper electrodes (A1 to A5). At the portion where the annular groove is formed, the piezoelectric element (10) includes a flexible portion formed so as to have thin thickness. When the peripheral portion of the piezoelectric element (10) is fixed to the casing, the central portion positioned within the annular groove functions as a weight caused to hang down from the flexible portion. On the lower surface of the piezoelectric element (10), a lower electrode (B) is formed. When force is applied to the weight by acceleration, the flexible portion is bent. As a result, predetermined charges are produced in the upper electrodes (A1 to A5) with the lower electrode (B) being as a reference potential. Accordingly, applied acceleration can be detected. When a predetermined a.c.
    Type: Grant
    Filed: February 15, 2000
    Date of Patent: August 7, 2001
    Assignee: Wacoh Corporation
    Inventor: Kazuhiro Okada
  • Patent number: 6253612
    Abstract: To achieve a drive-axis oscillation with improved frequency and amplitude stability, additional feedback loops are used to adjust force-feedback loop parameters. An amplitude-control loop measures oscillation amplitude, compares this value to the desired level, and adjusts damping of the mechanical sense-element to grow or shrink oscillation amplitude as appropriate. A frequency-tuning loop measures the oscillation frequency, compares this value with a highly stable reference, and adjusts the gain in the force-feedback loop to keep the drive-axis oscillation frequency at the reference value. The combined topology simultaneously controls both amplitude and frequency. Advantages of the combined topology include improved stability, fast oscillation start-up, low power consumption, and excellent shock rejection.
    Type: Grant
    Filed: May 28, 1999
    Date of Patent: July 3, 2001
    Assignee: Integrated Micro Instruments, Inc.
    Inventors: Mark A. Lemkin, Thor N. Juneau, William A. Clark, Allen W. Roessig
  • Publication number: 20010004846
    Abstract: A resonant element including: a vibrating body vibratable in orthogonal X- and Z-directions; exciting means for causing the vibrating body to be subjected to an excitation vibration in the X-direction; excitation deflection detecting means for detecting the deflection of the vibrating body in the Z-direction during the excitation vibration thereof in the X-direction; and excitation deflection inhibiting means for inhibiting the deflection of the vibrating body in the Z-direction.
    Type: Application
    Filed: December 5, 2000
    Publication date: June 28, 2001
    Applicant: Murata Manufacturing Co., Ltd.
    Inventor: Hiroshi Kawai
  • Patent number: 6249754
    Abstract: A device for determining a rotation rate can be employed in conjunction with a rotation rate sensor which furnishes one or two output signals that among other things are a measure for the Coriolis acceleration and thus also for the rotation rate. The device includes an arrangement for signal processing, with which both digital subtraction of the output signals and an ensuing digital multiplication by a carrier signal shifted in a digital phase shifter are accomplished. The digital multiplication is followed by a digital/analog conversion and low-pass filtration, which in the final analysis furnishes an output signal (DR) that is equivalent to the rotation rate.
    Type: Grant
    Filed: June 24, 1998
    Date of Patent: June 19, 2001
    Assignee: Robert Bosch GmbH
    Inventors: Reinhard Neul, Dirk Lamprecht
  • Patent number: 6244095
    Abstract: The present invention aims to present an angular velocity sensor having a self diagnosis function. An angular velocity sensor of the present invention includes a driving part for stably vibrating a driving part of a sensor element having a driver part and a detector part for detecting an angular velocity and detection means for detecting the angular velocity of the sensor element and obtains a self diagnosis signal for a malfunction by detecting a mechanical coupling signal obtained at the detection means.
    Type: Grant
    Filed: June 14, 1999
    Date of Patent: June 12, 2001
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Toshiyuki Nozoe, Takeshi Uemura, Masami Tamura
  • Patent number: 6230562
    Abstract: A detection circuit for a vibratory gyro includes a first circuit which detects a detection signal output from the vibratory gyro and produces an output signal indicative of an angular velocity applied to the vibratory gyro, and a second circuit which is operatively coupled to the first circuit and reduces a leakage component included in the detection signal.
    Type: Grant
    Filed: March 11, 1997
    Date of Patent: May 15, 2001
    Assignees: Fujitsu Limited, Fujitsu Towa Electron Limited
    Inventors: Hiroshi Ishikawa, Masanori Yachi, Sumio Yamada, Yoshitaka Takahashi, Yoshio Satoh