Abstract: Inertial sensor having a body with first and second cavities on opposite sides thereof, a sensing element in the first cavity, electronic circuitry in the second cavity, electrical conductors interconnecting the sensing element and the circuitry, and leads connected electrically to the circuitry and extending from the body for mounting the sensor and making connections with the circuitry.

Abstract: A micro-scale hemispherical resonator gyroscope includes a hemispherical resonator with a plurality of masses positioned around the periphery of the hemispherical resonator. At least some of the masses may be made of a heavy metal, such as tungsten, gold, platinum, or lead, and may be positioned at points of maximum deflection or velocity of the resonator. The hemispherical resonator may have a 2 mm diameter and a ring down time of at least 500 seconds.

Abstract: Techniques are provided to determine an initial quaternion transform that is used to transform measurements received from accelerometer, rate sensor and inertial reference subsystems from a vehicle coordinate frame to an inertial navigation frame. Methods disclosed determine corrective angular rates to use as a feedback signal to rotate the quaternion transform to counter errors that result when transforming a gravity vector and an inertial reference vector (e.g., a magnetic North reference vector) that are being measured by the accelerometer and an inertial reference subsystems, respectively. The initial quaternion determination is performed during a time period when the only substantial acceleration on the vehicle is due to gravity. The initial quaternion can be used for processing various guidance, navigation and control functions.

Abstract: Techniques are provided for reducing mount vibration in an inertial rate sensor (IRS). For example, if oscillation in an IRS's vibratory members, vibrating along a first axis, cause displacement in the IRS's mount along a second axis, the vibratory members can be aligned so that the vibratory members have some component of movement along the second axis during oscillation. This component of movement can help reduce the displacement of the IRS's mount along the second axis. It can further reduce sensitivity to changes in the boundary conditions of an IRS (e.g., vibrations and other movements at the mount from forces external to the IRS). Vibratory members further can have portions of increased mass at the vibratory members' tips, which can impact the alignment of the vibratory members. These examples, however, are not exhaustive.

Abstract: Solid state switching device having a heatsink, a solid state switching element in heat conductive relationship with the heatsink, and an enclosure having ventilation openings adjacent to the heatsink through which air can flow to remove heat from the heatsink. In some disclosed embodiments, the heatsink has fins and ducts aligned with ventilation openings in the enclosure for removing heat by radiation and convection. In others, the heatsink is a generally planar baseplate, with ventilation openings in a side wall of the enclosure next to the baseplate for removing heat from the device. Spacers project laterally from the devices and permit a plurality of the devices to mounted side-by-side with space between the devices through which air can flow.

Abstract: Techniques are provided for reducing mount vibration in an inertial rate sensor (IRS). For example, if oscillation in an IRS's vibratory members, vibrating along a first axis, cause displacement in the IRS's mount along a second axis, the vibratory members can be aligned so that the vibratory members have some component of movement along the second axis during oscillation. This component of movement can help reduce the displacement of the IRS's mount along the second axis. It can further reduce sensitivity to changes in the boundary conditions of an IRS (e.g., vibrations and other movements at the mount from forces external to the IRS). Vibratory members further can have portions of increased mass at the vibratory members' tips, which can impact the alignment of the vibratory members. These examples, however, are not exhaustive.

Abstract: Described herein is the sense element assembly for a capacitive pressure sensor and method for creating same that has increased sensitivity despite the parasitic capacitance that is created. The capacitive sensor element assembly, comprises a first semiconductive layer, and a first conductive layer, a first dielectric layer into which a cavity has been formed, the dielectric layer lying between the first semiconductive layer and the first conductive layer, wherein an electrical connection is made to the second conductive layer. A preferred method for fabricating a capacitive sensor assembly of the present invention comprises the steps of forming a dielectric layer on top of a conductive handle wafer; creating at least one cavity in the dielectric layer, bonding a thin semiconductive layer to the dielectric layer and connecting an operational amplifier to the input of the capacitive sensor assembly to overcome the parasitic capacitance formed during fabrication.

Abstract: Techniques are provided to determine an initial quaternion transform that is used to transform measurements received from accelerometer, rate sensor and inertial reference subsystems from a vehicle coordinate frame to an inertial navigation frame. Methods disclosed determine corrective angular rates to use as a feedback signal to rotate the quaternion transform to counter errors that result when transforming a gravity vector and an inertial reference vector (e.g., a magnetic North reference vector) that are being measured by the accelerometer and an inertial reference subsystems, respectively. The initial quaternion determination is performed during a time period when the only substantial acceleration on the vehicle is due to gravity. The initial quaternion can be used for processing various guidance, navigation and control functions.

Abstract: A micro-scale hemispherical resonator gyroscope includes a hemispherical resonator with a plurality of masses positioned around the periphery of the hemispherical resonator. At least some of the masses may be made of a heavy metal, such as tungsten, gold, platinum, or lead, and may be positioned at points of maximum deflection or velocity of the resonator. The hemispherical resonator may have a 2 mm diameter and a ring down time of at least 500 seconds.

Abstract: Hybrid power relay for making and breaking an electrical circuit which includes electromagnetically operated contacts for making and breaking the circuit, a solid state switch connected across the contacts, a control circuit responsive to a control signal for actuating the solid state switch and the contacts such that the solid state switch closes before the contacts to make the circuit and the contacts open before the solid state switch to break the circuit, and a protective circuit for monitoring the temperature of the solid state switch and opening the switch in the event of a rise in temperature produced by abnormal current flow in the switch due to failure of the contacts to make and maintain the circuit.

Abstract: Described herein is the sensor assembly and method for rapidly obtaining accurate readings of a variable. The sensor assembly comprises a plurality of sensors which are connected to a microcontroller that processes the signals of the individual transducers to the microcontroller. The microcontroller contains software that maximizes the refresh rate and/or minimizes the time it takes to process the outputs of each of the transducers. The microcontroller that is coupled to the sensor assembly selectively measures the outputs of each transducer so as to speed up the refresh rate of the sensor.

Abstract: Inertial sensor having a body with first and second cavities on opposite sides thereof, a sensing element in the first cavity, electronic circuitry in the second cavity, electrical conductors interconnecting the sensing element and the circuitry, and leads connected electrically to the circuitry and extending from the body for mounting the sensor and making connections with the circuitry.

Abstract: Described herein is the sense element assembly for a capacitive pressure sensor and method for creating same that has increased sensitivity without additional size. The sense element assembly and method includes fabricating an off-centered elliptically shaped center electrode, at least one elliptical annular-like electrode around the center electrode, a ground electrode and a method for fusing the layers together to optimize sensitivity.

Abstract: Dithering mechanism and method for eliminating the effects of zero-rate bias in a rate sensor or gyroscope. Both continuously moving and indexing embodiments are disclosed. The mechanism includes a first part mounted in a fixed position centered about a dither axis perpendicular to the input axis of the gyroscope, a second part disposed coaxially of the first part and affixed to the sensing element of the gyroscope, and a plurality of piezoelectrically driven quartz flexure beams extending radially between the first and second parts for dithering the second part about the dither axis. In some embodiments, the dithering mechanism is formed separately from and affixed to the sensing element of the gyroscope, and in others it is formed integrally with the sensing element.

Abstract: Tuning fork and method in which a pair of elongated tines having front and rear surfaces are disposed symmetrically about an axis, and balancing masses on the front surface of one tine and on the rear surface of the other tine are trimmed to reduce quadrature error and also to maintain mass balance between the tines.

Abstract: Inertial measurement system and method in which a gyroscope is periodically dithered about an axis perpendicular to its input axis, a signal from the gyroscope is delayed to provide a delayed signal which lags the gyroscope signal by one-half of the dithering period, and the delayed signal and the signal from the gyroscope are combined to provide an output signal from which the bias has been cancelled.

Abstract: Dithering mechanism and method for eliminating the effects of zero-rate bias in a rate sensor or gyroscope. Both continuously moving and indexing embodiments are disclosed. The mechanism includes a first part mounted in a fixed position centered about a dither axis perpendicular to the input axis of the gyroscope, a second part disposed coaxially of the first part and affixed to the sensing element of the gyroscope, and a plurality of piezoelectrically driven quartz flexure beams extending radially between the first and second parts for dithering the second part about the dither axis. In some embodiments, the dithering mechanism is formed separately from and affixed to the sensing element of the gyroscope, and in others it is formed integrally with the sensing element.

Abstract: A voice coil actuator having a capacitive sensor. A magnetic housing contains at least one magnet, and has a wall that defines a first cavity. A magnetic core is coupled to the magnetic housing and extend from an interior surface of the magnetic housing in a direction of a center axis of the wall of the magnetic housing. A coil assembly has a wall defining a second cavity that at least partly envelops the magnetic core, disposed at least partly inside the first cavity, and adapted to move linearly with respect to the magnetic housing. The coil assembly forms a capacitive sensor with the magnetic core, the capacitive sensor adapted to measure at least one of position, velocity and acceleration of the coil assembly with respect to the magnetic housing.

Abstract: System having one or more inertial sensors in which one or more of the sensor input axes are modulated in orientation about an axis substantially perpendicular to the input, or sensitive, axis of the sensor and, in some embodiments, by also enhancing the accuracy of such a system to provide improved signal to noise ratio and reduced sensitivity to errors in alignment of the sensor axes to the dither axes.

Abstract: Angular rate sensor for detecting rotation about first and second mutually perpendicular axes which has first and second masses coupled together for torsional drive mode oscillation of equal amplitude and opposite phase about third axes which are perpendicular to the first and second axes. The first mass is mounted for oscillation about the second axis in response to Coriolis forces produced by rotation about the first axis, and the second mass is mounted for oscillation about the first axis in response to Coriolis forces produced by rotation about the second axis. In some disclosed embodiments, the rate sensor also includes a pair of accelerometer masses which are connected together for torsional movement of equal amplitude and opposite phase about axes parallel to the third axes in response to acceleration along the second axis and for torsional movement of equal amplitude and opposite phase about axes parallel to the second axis in response to acceleration along the third axes.