Electrostatic gyroscope drift caused by rotor asphericity
Calculating drift of electrostatic gyroscopes due to rotor asphericity
Martynenko, Yu. G.↗
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The Gravity Probe B electrostatic gyroscope suspension system (GSS)
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W J Bencze↗
Unconventional inertial sensors.
Inertial sensors, discussing magnetic resonance and superconductor gyroscopes, ring lasers, fluid dynamical devices, electrostatic gyroscopes, etc
CRYOGENIC GYROSCOPE↗
Electrostatically controlled micromechanical gyroscope
An integrated electrostatically-controlled micromechanical gyroscope with a rotor encompassed within a rotor cavity and electrostatically spun within the cavity. The gyroscope includes a plurality of axial electrostatic rotor actuators above and below the rotor for controlling the axial and tilt position of the rotor within the cavity, and a plurality of radial electrostatic actuators spaced circumferentially around the rotor for controlling the radial and tilt position of the rotor within the cavity. The position of the rotor within the cavity is then resolved to determine the external forces acting on the rotor.
Hawkey, Timothy↗
Design of a gas spin-up system for an electrostatically supported cryogenic gyroscope.
Gas spin-up system for electrostatically supported cryogenic gyroscope noting design
Bracken, T. D.↗
Studies relevant to the electric vacuum gyro program of electrical breakdown in ultrahigh vacuum Final report
Electrical breakdown in ultrahigh vacuum studied for electrostatic gyroscope development
ELECTRIC BREAKDOWN↗
Spacecraft control
Partial inertial system integration tests, automatic lens design, and vibration and shock analyses of electrostatic gyroscope
Source record↗
Non-inertial calibration of vibratory gyroscopes
The electrostatic elements already present in a vibratory gyroscope are used to simulate the Coriolis forces. An artificial electrostatic rotation signal is added to the closed-loop force rebalance system. Because the Coriolis force is at the same frequency as the artificial electrostatic force, the simulated force may be introduced into the system to perform an inertial test on MEMS vibratory gyroscopes without the use of a rotation table.
Gutierrez, Roman C.↗
Development of sputter coatings for the gravity probe B gyroscope housings
Cu/Ti coatings have been applied by sputter deposition to fused quartz housings to serve as the electrodes and lands of electrostatically supported gyroscopes. Niobium-coated fused quartz gyro rotors have been successfully suspended and spun up in those housings. The Cu/Ti bilayer coating and alternative multilayer coatings (Cu/Mo, Mo/Cu/Ti and Mo/Cu/Mo) with 2-micron thickness produced by sputter deposition on flat, fused quartz substrates have been examined with scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and four-point resistivity measurement techniques. The multilayer coatings with a molybdenum bonding layer appear to produce smoother surfaces than those with a titanium bonding layer. All multilayer coatings survived thermal cycling to 77 K without adhesion failure.
Zhou, P.↗
Gradiometry coexperiments to the gravity probe B and step missions
The Gravity Probe-B (GP-B) spacecraft, designed to test predictions of general relativity, will fly in the mid 1990s. It will carry four electrostatically suspended gyroscopes in a cryogenic environment and will have a drag-free control system to minimize disturbances on the gyroscopes. The Stanford Test of Equivalence Principle (STEP) spacecraft, to fly later, will carry a set of test masses under very similar conditions. The possibility of using differential measurements of the GP-B gyroscopes suspension forces and the STEP tests mass displacement readout to form single-axis gravity gradiometers is explored. It is shown that the noise in the suspension systems is sufficiently small in the relevant frequency range, and that enough information is collected to compensate for the spacecrafts' attitude motion. Finally, using Breakwell's flat-earth approximation, these experiments are compared to other geodesy experiments and predict the contribution they can make to the knowledge of the Earth's geopotential.
Tapley, M.↗
Electrostatically suspended and sensed micro-mechanical rate gyroscope
The goal of this work is development of fully electrostatically suspended and rebalancing angular rate sensing micro-gyroscope fabricated according to standard VLSI techniques. Fabrication of test structures is proceeding. Off chip electronics for the electrostatic sensing and driving circuits has been tested. The prototype device will be assembled in a hybrid construction including the FET input stages of the sensors.
Torti, R.↗
Results of dynamic testing of GP-B spherical gyroscopes
Laboratory tests of the spherical electrostatically levitated cryogenically cooled coated gyroscope being developed for the Gravity Probe B (GP-B) spacecraft (Bardas et al., 1986) are reported. Spin speed and the dc components of the trapped magnetic field are measured with three orthogonal pickup loops attached to SQUID detectors as the levitated gyro is brought up to speed by an He gas jet. Data on the spin-vector time history, mass unbalance, higher rotor-shape harmonics, and spin-vector position are presented in extensive graphs and characterized in detail, and a mathematical model of the electrostatic suspension torques is derived. Prototype gyro 86-4 is found to have mass unbalance within the range required for the GP-B mission (to detect the geodetic and motional effects predicted by general relativity theory).
Keiser, G. M.↗
Unconventional inertial sensors.
Inertial sensors reviewing ring laser, electrostatic fluid sphere, magnetic resonance, superconductivity gyroscope, relativistic rotating tensor, vortex rate and quantum mechanical effect sensing
INERTIAL ACCELEROMETER↗
An electrostatically suspended, micro-mechanical rate gyroscope
SatCon Technology has performed a study of micromechanical gyroscopes. The goals of this program were to define a baseline system configuration and establish technical feasibility for proof of principle and prototype fabrication. This report documents the research and presents the baseline mechanical design, sensors, control systems, and electronics. This section presents a project overview and specific technical objectives. Section 2 contains a background on micromechanical technology. Section 3 contains the microgyroscope specifications and configurations. Section 4 contains the electromechanical design. Section 5 outlines the control and electronics. Section 6 presents a preliminary sequence for microfabrication of the baseline design, and Section 7 contains conclusions and recommendations for further work.
Hawkey, Timothy↗
Cloverleaf microgyroscope with electrostatic alignment and tuning
A micro-gyroscope (10) having closed loop output operation by a control voltage (V.sub.ty), that is demodulated by a drive axis (x-axis) signal V.sub.thx of the sense electrodes (S1, S2), providing Coriolis torque rebalance to prevent displacement of the micro-gyroscope (10) on the output axis (y-axis) V.sub.thy.about.0. Closed loop drive axis torque, V.sub.tx maintains a constant drive axis amplitude signal, V.sub.thx. The present invention provides independent alignment and tuning of the micro-gyroscope by using separate electrodes and electrostatic bias voltages to adjust alignment and tuning. A quadrature amplitude signal, or cross-axis transfer function peak amplitude is used to detect misalignment that is corrected to zero by an electrostatic bias voltage adjustment. The cross-axis transfer function is either V.sub.thy/V.sub.ty or V.sub.tnx/V.sub.tx. A quadrature signal noise level, or difference in natural frequencies estimated from measurements of the transfer functions is used to detect residual mistuning, that is corrected to zero by a second electrostatic bias voltage adjustment.
Challoner, A. Dorian↗
Integrated microgyroscope
SalCon Technology Corporation is developing a prototype electrostatically suspended micromechanical gyroscope in the Small Business Innovation Research (SBIR) program under Contracts 19282, and 19585 from NASA Langley Research Center. This paper presents the results of the Phase 1 feasibility study and the plans for fabrication in the upcoming Phase 2 program.
Hawkey, Timothy J.↗
Electrostatic spring softening in redundant degree of freedom resonators
The present invention discloses an isolated electrostatic biased resonator gyroscope. The gyroscope includes an isolated resonator having a first and a second differential vibration mode, a baseplate supporting the isolated resonator, a plurality of excitation affixed to the baseplate for exciting the first differential vibration mode, a plurality of sensing electrodes affixed to the baseplate for sensing movement of the gyroscope through the second differential vibration mode and a plurality of bias electrodes affixed to the baseplate for trimming isolation of the resonator and substantially minimizing frequency split between the first and second differential vibration modes. Typically, the isolated resonator comprises a proof mass and a counterbalancing plate with the bias electrodes disposed on the baseplate below.
Hayworth, Ken J.↗