Abstract: The present invention discloses a resonator gyroscope comprising a resonator including two bodies, each with a center of mass and transverse inertia symmetry about an axis that are substantially coincident and each supported by one or more elastic elements and wherein the bodies together forming two differential rocking modes of vibration transverse to the axis with substantially equal frequencies and wherein the two bodies transfer substantially no net momentum to the baseplate when the resonator is excited. The gyroscope further includes a baseplate affixed to the resonator by the one or more elastic elements and sense and drive elements each affixed to the resonator and baseplate.

Abstract: The present invention discloses a robotic manipulator, comprising at least one joint, each joint having a drive axis and at least one microelectromechanical system (MEMS) inertial sensor aligned with at least one drive axis providing sensing of a relative position of the drive axis. The robotic manipulator can include an inertial measurement unit (IMU) coupled to the robotic manipulator for determining the end effector position and orientation. A controller can be used, receiving a signal from at least one MEMS inertial sensor and controlling at least one joint drive axis in response to the signal to change the relative position of the joint drive axis. Rate information from MEMS sensors can be integrated to determine the position of their respective drive axes.

Abstract: An apparatus and method, for determining an instrument boresight heading. The apparatus comprises an instrument having a boresight, an elevation positioner for positioning the elevation of the instrument boresight having an elevation axis, an azimuth positioner for positioning the azimuth of the instrument boresight having an azimuth axis and a sensor including a gyro having a sensitive axis. The method comprises recording a first output of a gyro of an azimuth positioner having an instrument boresight azimuth heading in a first position, rotating the azimuth positioner to a second position, recording a second output of the gyro and rotating the azimuth positioner to a third position, recording a third output of the gyro and determining the azimuth heading relative to true north from the first, second and third output.

Abstract: The present invention discloses a resonator gyroscope comprising a vibrationally isolated resonator including a proof mass, a counterbalancing plate having an extensive planar region, and one or more flexures interconnecting the proof mass and counterbalancing plate. A baseplate is affixed to the resonator by the one or more flexures and sense and drive electrodes are affixed to the baseplate proximate to the extensive planar region of the counterbalancing plate for exciting the resonator and sensing movement of the gyroscope. The isolated resonator transfers substantially no net momentum to the baseplate when the resonator is excited.

Abstract: A micro-gyroscope having electronic alignment by performing an electronic coordinate transformation on control voltages (VTx, VTy) through an attenuator network thereby canceling first and second harmonic signals from the output (Vthx, Vthy). The micro-gyroscope is tuned by automatic electronic compensation based on quadrature error that is applied to correct for variations in the gyroscope.

Abstract: The present invention discloses methods of manufacturing mechanical resonator microgyroscopes using focused ion beam machining and the mechanical resonator gyroscopes produced therefrom. An exemplary method of tuning a mechanical resonator gyroscope, includes the steps of mounting a mechanical resonator gyroscope in a vacuum chamber with a controllable focused ion beam where the gyroscope includes exciting and sensing elements for measuring a resonant frequency of the gyroscope. The exciting and sensing elements are activated to measure the resonant frequency of the mechanical resonator gyroscope and the resonant frequency of the gyroscope is adjusted to a desired resonant frequency value by controlling the focused ion beam to remove material of the gyroscope.

Abstract: A micro-gyroscope (10) having closed loop operation by a control voltage (Vty), that is demodulated by an output signal of the sense electrodes (S1, S2), providing Coriolis torque rebalance to prevent displacement of the micro-gyroscope (10) on the output axis (y-axis). The present invention provides independent alignment and tuning of the micro-gyroscope by using separate sensors and actuators to detect and adjust alignment and tuning. A quadrature amplitude signal is used to detect misalignment, that is corrected to zero by an electrostatic bias adjustment. A quadrature signal noise level, or a transfer function test signal, is used to detect residual mistuning, that is corrected to zero by a second electrostatic bias adjustment.

Abstract: The present invention discloses a resonator gyroscope comprising a resonator including two bodies, each with a center of mass and transverse inertia symmetry about an axis that are substantially coincident and each supported by one or more elastic elements and wherein the bodies together forming two differential rocking modes of vibration transverse to the axis with substantially equal frequencies and wherein the two bodies transfer substantially no net momentum to the baseplate when the resonator is excited. The gyroscope further includes a baseplate affixed to the resonator by the one or more elastic elements and sense and drive elements each affixed to the resonator and baseplate.

Abstract: An apparatus and method, for determining an instrument boresight heading. The apparatus comprises an instrument having a boresight, an elevation positioner for positioning the elevation of the instrument boresight having an elevation axis, an azimuth positioner for positioning the azimuth of the instrument boresight having an azimuth axis and a sensor including a gyro having a sensitive axis. The method comprises recording a first output of a gyro of an azimuth positioner having an instrument boresight azimuth heading in a first position, rotating the azimuth positioner to a second position, recording a second output of the gyro and rotating the azimuth positioner to a third position, recording a third output of the gyro and determining the azimuth heading relative to true north from the first, second and third output.

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).

Abstract: A micro-gyroscope (10) having closed loop operation by a control voltage (VTY), that is demodulated by an output signal of the sense electrodes (S1, S2), providing Coriolis torque rebalance to prevent displacement of the micro-gyroscope (10) on the output axis (y-axis). The present invention provides wide-band, closed-loop operation for a micro-gyroscope (10) and allows the drive frequency to be closely tuned to a high Q sense axis resonance. A differential sense signal (S1−S2) is compensated and fed back by differentially changing the voltage on the drive electrodes to rebalance Coriolis torque. The feedback signal is demodulated in phase with the drive axis signal (K&ohgr;⊖x) to produce a measure of the Coriolis force.

Abstract: Various structures for cantilever beam tunneling rate gyro devices formed on a single substrate are disclosed. A cantilever electrode having a plurality of portions extending from the substrate with one end of the cantilever is suspended above the substrate at a distance from a tunneling electrode so that a tunneling current flows through the cantilever and tunneling electrode in response to an applied bias voltage. The cantilever and tunneling electrodes form a circuit that produces an output signal. A force applied to the sensor urges the cantilever electrode to deflect relative to the tunneling electrode to modulate the output signal. The output signal is a control voltage that is applied between the cantilever electrode and a control electrode to maintain a constant tunneling current. In the preferred embodiment, two cantilever portions extend from the wafer surface forming a Y-shape. In a further embodiment, a strap is fabricated on the cantilever electrode.

Abstract: Various structures for cantilever beam tunneling rate gyro devices formed on a single substrate are disclosed. A cantilever electrode having a plurality of portions extending from the substrate with one end of the cantilever is suspended above the substrate at a distance from a tunneling electrode so that a tunneling current flows through the cantilever and tunneling electrode in response to an applied bias voltage. The cantilever and tunneling electrodes form a circuit that produces an output signal. A force applied to the sensor urges the cantilever electrode to deflect relative to the tunneling electrode to modulate the output signal. The output signal is a control voltage that is applied between the cantilever electrode and a control electrode to maintain a constant tunneling current. In the preferred embodiment, two cantilever portions extend from the wafer surface forming a Y-shape. In a further embodiment, a strap is fabricated on the cantilever electrode.

Abstract: The invention provides a method for controlling the precession of a spinning spacecraft (20) which allows the spacecraft body to respond to an input torque without the nutation normally attendant when an input torque is applied about one transverse axis to accelerate a spinning spacecraft about that one axis. Dynamic decoupling eliminates nutation through the impression of additional derived feedback torques (44,46) to the input torque control of a spinning spacecraft to oppose or cancel the intrinsic cross-coupling terms (34,36) of the spinning spacecraft's gyrodynamics that give rise to the nutation.

Abstract: Various structures for cantilever beam tunneling rate gyro devices formed on a single substrate are disclosed. A cantilever electrode having a plurality of portions extending from the substrate with one end of the cantilever is suspended above the substrate at a distance from a tunneling electrode so that a tunneling current flows through the cantilever and tunneling electrode in response to an applied bias voltage. The cantilever and tunneling electrodes form a circuit that produces an output signal. A force applied to the sensor urges the cantilever electrode to deflect relative to the tunneling electrode to modulate the output signal. The output signal is a control voltage that is applied between the cantilever electrode and a control electrode to maintain a constant tunneling current. In the preferred embodiment, two cantilever portions extend from the wafer surface forming a Y-shape. In a further embodiment, a strap is fabricated on the cantilever electrode.

Abstract: A method and apparatus of determining the fill fraction of a liquid in a spacecraft in weightless space is disclosed. A small motion is introduced about the center of mass of the spacecraft undergoing steady spin and/or thrust, and resulting spacecraft oscillations are sensed. The measured frequency, amplitude and phase of the spacecraft oscillations are compared with counterpart values predicted for possible liquid quantities by a nonempirically computed model of spacecraft dynamics.

Abstract: Agile (electronically steerable) beam sensing with associated on-board processing, previously used exclusively for positioning of antennas for beam formation and tracking in communications systems, is now also used for satellite active attitude determination and control. A spinning satellite (100) is nadir oriented and precessed at orbit rate using magnetic torquing determined through use of an on-board stored magnetic field model (520) and attitude and orbit estimates (212). A Kalman filter (211) predicts parameters (202, 203) associated with a received signal (204) impinging on the satellite's wide angle beam antenna (201). The antenna system measures the error between the parameter predictions and observed values and sends appropriate error signals (207) to the Kalman filter for updating its estimation procedures.

Abstract: An axial electrostatic ion thruster for use on a dual-spin stabilized spacecraft is disclosed. The thruster is mounted on the spun portion of the spacecraft and continuously fired for an integral number of spin periods to provide north-south velocity and attitude control. To achieve zero attitude precession with a statically imbalanced despun platform, or an intentional attitude precession generally, the ion thrust is spin-synchronously varied between two non-zero levels to achieve a prescribed Fourier component amplitude and phase at the spin frequency. Modulation of the thrust is achieved with constant ion beam current by complementary modulation of the beam voltage, V.sub.B, and accel voltage, V.sub.A by varying the ion extraction system grid voltages. This varies the thrust while maintaining a constant total accelerating voltage V.sub.TOT =V.sub.B +.vertline.V.sub.A .vertline..