Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01C—MEASURING DISTANCES, LEVELS OR BEARINGS; SURVEYING; NAVIGATION; GYROSCOPIC INSTRUMENTS; PHOTOGRAMMETRY OR VIDEOGRAMMETRY
  • G01C19/00—Gyroscopes; Turn-sensitive devices using vibrating masses; Turn-sensitive devices without moving masses; Measuring angular rate using gyroscopic effects
  • G01C19/56—Turn-sensitive devices using vibrating masses, e.g. vibratory angular rate sensors based on Coriolis forces
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01C—MEASURING DISTANCES, LEVELS OR BEARINGS; SURVEYING; NAVIGATION; GYROSCOPIC INSTRUMENTS; PHOTOGRAMMETRY OR VIDEOGRAMMETRY
  • G01C19/00—Gyroscopes; Turn-sensitive devices using vibrating masses; Turn-sensitive devices without moving masses; Measuring angular rate using gyroscopic effects
  • G01C19/56—Turn-sensitive devices using vibrating masses, e.g. vibratory angular rate sensors based on Coriolis forces
  • G01C19/5719—Turn-sensitive devices using vibrating masses, e.g. vibratory angular rate sensors based on Coriolis forces using planar vibrating masses driven in a translation vibration along an axis
  • G01C19/5733—Structural details or topology
  • G01C19/5755—Structural details or topology the devices having a single sensing mass
  • G01C19/5762—Structural details or topology the devices having a single sensing mass the sensing mass being connected to a driving mass, e.g. driving frames

Definitions

• the present invention relates to a vibratory micromachined
• gyroscope and more particularly, to a vibratory micromachined gyroscope
• an angular rate sensor for detecting an angular rate
• gyroscope is to detect an angular rate of an inertial body vibrating or rotating
• first axis about one axis (referred to as "first axis") by detecting Coriolis' force that is
• inertial body receives input of an angular rate from a third direction
• Another object of the present invention is to provide an angular rate
• Another aspect of the present invention may comprise a drive gimbals for
• FIG. 1 is a perspective view of a micromachined gyroscope
• FIG. 2 is a plane view of the micromachined gyroscope of FIG. 1 :
• FIG. 3 illustrates the operational principles of the micromachined
• FIG. 4 is a perspective view of mode flexures 3, 4 of the
• FIG. 5a is a perspective view of a parallel plate capacitor
• FIG. 5b is a perspective view of a transverse comb capacitor
• FIG. 6 is a circuit diagram showing one embodiment of the present
• FIG. 7a is a circuit diagram showing the angular rate measurement
• FIG. 7b shows graphical representations of output processes of
• FIG. 8 shows output wave forms of the gyroscope according to one
• FIG. 9 is a graphical representation showing voltage outputs for
• FIG.1 is a perspective view of a micromachined gyroscope according
• FIG. 2 is a plane view of
• a micromachined gyroscope of the present invention comprises an
• outer sensor gimbals 1 an inner drive gimbals 2, a fixed anchor 11 of the gimbals, a driven mode flexure 3 for connecting the inner drive gimbals 2
• the inner drive gimbals 2 comprises C-shaped frames placed on both
• the inner drive gimbals 2 also comprises a driven mode flexure 3
• the driven mode flexure 3 connects the inner drive gimbals 2 and the
• outer sensor gimbals 1 comprises an H-shaped frame surrounding the inner
• the outer sensor gimbals 1 is connected with the inner drive gimbals 2 by a sensor mode flexure 4 movable in the Y-axis direction.
• the number of sensor electrodes 7, 8 is provided. The number of sensor electrodes
• tuning electrode 6 and drive electrode 5 can be changed as necessary.
• Rebalancing electrodes 9 are provided on both ends of the frame of the
• the gimbals 1 , 2 are suspended by the fixed
• the thickness of the structure is above a certain limit.
• the outer sensor gimbals 1 the closed H-shape curve, is also mechanically
• the tuning electrodes 6 are placed on both sides of the sensor comb
• the tuning electrode 6 can restrain the
• the rebalancing electrode 9 helps to improve the accuracy for the
• MEMS micro electro-mechanical system
• the present invention employs a
• FIG.1 shows the
• micromachined gyroscope structured as above.
• micromachined gyroscope of the present invention As stated, the micromachined gyroscope of the present invention
• micromachined gyroscope of the present invention is a micromachined gyroscope of the present invention.
• planar gimbals structured micromachined gyroscope according to
• the present invention does not show a decrease in its functional performance
• micromachined gyroscope of the present invention is made to
• FIG. 3 illustrates the driving principle of the micromachined gyroscope
• the gimbals 1 , 2 are vibrated in the X-axis direction when a specific
• drive electrode 5 applies impulses to the drive comb of the inner drive
• mode flexure 4 is not movable in the X-axis direction.
• the inner drive gimbals 2 does not incur a displacement in the Y-
• the outer sensor gimbals 1 vibrates in the direction perpendicular to the
• planar mode flexure structure which is rigid in the above drive
• the corresponding angular rate can be
• micromachined gyroscope of the present invention is
• flexures 3,4 are all evenly placed on one plane and are of the same material
• planar vibratory gyroscope of the present invention is
• FIG. 4 is a perspective view of mode flexures 3, 4 of the micromachined
• the mode flexures 3, 4 are cubical, with height, length and thickness
• the flexure constant of the driven mode flexure 3 is determined below.
• x0 is a flexure constant of one part of the driven mode flexure 3
• k x is a flexure constant over the entire driven mode flexure 3.
• the flexure constant of the sensor mode flexure 4 is determined below. k .
• ⁇ is a flexure constant of one part of the sensor mode flexure 4, and
• the sense mass is the mass of the outer sensor gimbals 1 only and is
• planar vibratory gyroscope is not impacted by height (h).
• a processing error significantly affecting the resonant frequency is the one for a thickness (t) of a flexure along with the
• micromachined gyroscope is the ratio of the resonant frequency of the drive
• the resonant frequency may vary
• gyroscope has a planar vibration structure.
• the thickness (f) is
• the present invention having a frame structure, the effect of the processing errors can be eliminated by making the flexure thickness (t) of the drive part
• FIG. 5a is a perspective view of a parallel plate capacitor
• FIG. 5b is a perspective view of a transverse comb capacitor employed in
• micromachined gyroscope according to the present invention is
• transverse comb capacitance sensor structure as shown in FIGs. 5 and 6.
• the capacitance of the parallel plate electrode is given by
• g is the gap between two plates.
• g is the gap between electrodes.
• the electrode is 5 m and the gap (g) is 2 ⁇ n in the transverse comb case.
• the area of the two capacitors on the substrates are given by
• structure size can be reduced so that the structure is more mechanically rigid.
• transverse comb electrode structure can provide a greater
• the thickness is
• comb electrode referred to as "comb electrode” and the sensor electrode 7, 8 is
• the gyroscope of the present invention improved its non-linearity by adoption
• FIG. 6 is a circuit diagram showing one embodiment of the present
• the comb electrode is connected with the negative input terminal of
• the positive input terminal of the OP amp is
• the circuits form an integrator to show the
• Table 3 shows the design variables for the capacitance detection of the sensor part.
• the capacitance variation according to the minor displacement can be any capacitance variation according to the minor displacement.
• present invention primarily depends on the displacement of the outer sensor
• angular rate sensor is a four-order system
• the sensor part according to the outer applied angular rate.
• FIG. 7a is a circuit diagram showing the angular rate measurement
• FIG. 7b shows graphical representations of output processes of angular
• a drive circuit 100 is connected to the drive
• a sense wire is connected to the fixed anchor 1 1 , and the sense wire is disposed such that sensor signals are output through an amplifier 300, a
• HPF high-pass filter
• BPF band-pass filter
• the micromachined gyroscope is driven by the application of a 400mV
• the sensor part comprises a charge amplifier using a difference
• gyroscope is 40kHz, and the modulated angular rate signal, as shown in FIG.
• the gyroscope circuit is installed inside the vacuum chamber located
• FIGs. 8 and 9 are shown in FIGs. 8 and 9.
• FIG. 8 shows output waveforms of the gyroscope according to one
• FiG. 8 shows output waves when the
• angular rate signal is applied at 1 deg/sec and 5Hz sine wave, and the noise
• FIG. 9 is a waveform of applied angular rates to detected voltage
• micromachined gyroscope according to the present invention is

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• 2000
  • 2000-06-20 KR KR10-2000-0033928A patent/KR100373484B1/ko not_active IP Right Cessation
• 2001
  • 2001-01-22 JP JP2001555769A patent/JP2003531359A/ja active Pending
  • 2001-01-22 AU AU30624/01A patent/AU3062401A/en not_active Abandoned
  • 2001-01-22 US US10/182,214 patent/US20030084722A1/en not_active Abandoned
  • 2001-01-22 WO PCT/KR2001/000109 patent/WO2001055674A2/en active Application Filing
  • 2001-01-22 DE DE10195200T patent/DE10195200B4/de not_active Expired - Fee Related

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