Abstract: Quadrature error occurs in Corolis based vibrating rate sensors because of manufacturing flaws that permit the sensing element to oscillate either linearly along or angularly about an axis that is not orthogonal to the output axis. This creates an oscillation along or about the output axis that is a component of the sensing element's vibration acceleration. This output axis oscillation is in phase with the driven acceleration of the sensing element and is called quadrature error since it is ninety degrees out of phase with the angular rate induced Coriolis acceleration. Rather than applying forces that reorient the axis of the driven vibration to be orthogonal to the output axis to eliminate the output axis oscillation, the present invention applies sinusoidal forces to the sensing element by means of a quadrature servo to cancel the output oscillation.

Abstract: A method of field-assisted fusion bonding produces multiple-layer devices. Contacts (301, 303, 305, 307, 309) are placed at various points along different surfaces of a combination of two or more wafers (201, 203, 205, 501, 503, 505, 801, 803). An electric field is applied to the contacts (301, 303, 305, 307, 309), thereby creating an electrostatic attractive force between the wafers (201, 203, 205, 501, 503, 505, 801, 803). The temperature of the wafer combination is elevated to a fusion bonding temperature while the electric field is applied.

Abstract: A micromachined silicon tuned accelerometer gyro is formed out of silicon wafers, by micromachining. The top and bottom cover which include driver, forcer, tuning and guard ring elements mounted therein are micromachined in arrays on silicon-on-insulator (SOI) wafers. The center (driver and sensing) element between the top and bottom is micromachined in an array of four inch diameter silicon wafers. The driver and sensing structure is a tuned pendulum attached by flexure joints to a vibrating structure which is in then suspended by a parallelogram dither suspension. The pendulum is tuned by adjusting the magnitude of a d.c. signal to match the natural frequency of the pendulum to the natural frequency of the vibrating structure. The dither suspension flexures of the vibrating structure is uniquely defined and easily machined but yet provides a dither suspension that restrains the vibrating structure within its vibrating plane with no harmonic distortion.

Abstract: A bi-stable micro-actuator is formed from a first and a second silicon-on-insulator wafer fused together at an electrical contact layer. A cover with a V-groove defines an optical axis. A collimated optical signal source in the V-groove couples an optical signal to an optical port in the V-groove. A mirror surface on a transfer member blocks or reflects the optical signal. The transfer member has a point of support at the first and second end. The mirror blocks or reflects the optical axis. An expandable structure applies a compressive force between the first and second point of support of the transfer member along a compressive axis to hold the transfer member in a bowed first state or a bowed second state. A control signal applied to a heating element in the expandable structure reduces the compressive force, switching the transfer member to a second state.

Abstract: A simplified and smaller accelerometer-gyro is provided by combining gyro and accelerometer functions in a single sensor unit which has a pair of counter oscillating accelerometers each having a pendulum or sense element and a vibrating element. The pendulum and vibrating element of each accelerometer are designed to be symmetrical so that the center of mass for each accelerometer are on a line which is parallel to the dither motion of the unit. The geometry of these two pendulums is configured so that the centers of percussion of each is at the same point. Electrodes on the top and bottom cover of the sensor unit combine the pickoff and forcing function with the pendulum tuning function, thereby simplifying electrical connection. A pair of mounting tabs are fastened to the frame by respective compliant beams. The accelerometer-gyro may be mounted in an enclosure that maintains a pressure below atmospheric around the accelerometer-gyro.

Abstract: A bi-stable micro-actuator is formed from a first and a second silicon-on-insulator wafer fused together at an electrical contact layer. A cover has a V-groove that defines an optical axis. A collimated optical signal source in the V-groove couples an optical signal to an optical port in the V-groove. A mirror surface on the transfer member blocks or reflects the optical signal. The transfer member has a point of support at the first and second end. The central portion of the transfer member carrying a mirror is displaced from the compressive axis with transfer member in a bowed first or second state. The mirror blocks or reflects the optical axis. An expandable structure applies a compressive force between the first and second point of support along the compressive axis to hold the transfer member in a bowed first state or a bowed second state. A control signal is applied to a heating element in the expandable structure to reduce the compressive force transferring the transfer member to a second state.

Abstract: An integrated rate and accelerometer sensor includes two counter vibrating tuned accelerometers formed in a single substantially planar silicon body to form the sensing element. The two vibrating accelerometers are interleaved in a manner that places their respective centers of mass in the same line parallel to the direction of the vibration and has the centers of percussion of the two (pendulum) proof masses coincident. A phase insensitive quadrature nulling method is utilized for each of the two vibrating accelerometers. The sensor structure utilizes Pyrex for the top and bottom covers. Metalized electrodes, feedthrus and contact pads are also utilized for the sensing element, instead of interlayer wire bonds.

Abstract: A simplified and smaller accelerometer-gyro is provided by combining gyro and accelerometer functions in a single sensor unit which has a pair of counter oscillating accelerometers each having a pendulum or sense element and a vibrating element. The pendulum and vibrating element of each accelerometer are designed to be symmetrical so that the center of mass for each accelerometer are on a line which is parallel to the dither motion of the unit. The geometry of these two pendulums is configured so that the centers of percussion of each is at the same point. Electrodes on the top and bottom cover of the sensor unit combine the pickoff and forcing function with the pendulum tuning function, thereby simplifying electrical connection. A pair of mounting tabs are fastened to the frame by respective compliant beams. The accelerometer-gyro may be mounted in an enclosure that maintains a pressure below atmospheric around the accelerometer-gyro.

Abstract: A marine docking device according to the present invention includes a fender having a first end coupled to a first arm by a first attachment member and a second end coupled to a second arm by a second attachment member. The first attachment member and the second attachment member are configured to prevent the fender from rotating about a longitudinal axis that passes through the first end and the second end. The first arm includes a compression assembly that facilitates movement of the first end between a first position and a second position. The compression assembly includes a tubular member that is slidable within a sleeve. A spring is compressed between a first spring abutment provided on the sleeve and a second spring abutment provided on the tubular member. The first spring abutment is continuously urged toward an advanced position by the spring.

Abstract: A rotation sensing system includes a rotation sensor that produces a signal in response to an input rotation about a sensing axis. A servo system is arranged to rotate the rotation sensor at an angle about the sensing axis to null the signal from the rotation sensor such that the rotation sensor is substantially inertially stable. The rotation sensing system is mounted on a resolver arranged to measure the angle through which the servo system has rotated the rotation sensor.

Abstract: An infra-red camera apparatus having a primary mirror assembly formed in a first molded plastic housing; and, a secondary mirror assembly formed in a second molded plastic housing and disposed in front of and in optical alignment with the primary mirror assembly for collecting an image. The first and second housings snap together for assembly of the camera. A focal plane array is disposed in optical alignment with the primary and secondary mirrors for receiving an image focused thereon by the secondary mirror. A substrate is added for supporting the focal plane array and system electronics, which are responsive to images formed on the focal plane array.

Abstract: A simplified and smaller accelerometer-gyro is provided by combining gyro and accelerometer functions in a single sensor unit which has a pair of counter oscillating accelerometers each having a pendulum or sense element and a vibrating element. The pendulum and vibrating element of each accelerometer are designed to be symmetrical so that the center of mass for each accelerometer are on a line which is parallel to the dither motion of the unit. The geometry of these two pendulums is configured so that the centers of percussion of each is at the same point. Electrodes on the top and bottom cover of the sensor unit combine the pickoff and forcing function with the pendulum tuning function, thereby simplifying electrical connection. A pair of mounting tabs are fastened to the frame by respective compliant beams. The accelerometer-gyro may be mounted in an enclosure that maintains a pressure below atmospheric around the accelerometer-gyro.

Abstract: A simplified and smaller accelerometer-gyro is provided by combining gyro and accelerometer functions in a single sensor unit which has a pair of counter oscillating accelerometers each having a pendulum or sense element and a vibrating element. The pendulum and vibrating element of each accelerometer are designed to be symmetrical so that the center of mass for each accelerometer are on a line which is parallel to the dither motion of the unit. The geometry of these two pendulums is configured so that the centers of percussion of each is at the same point. Electrodes on the top and bottom cover of the sensor unit combine the pickoff and forcing function with the pendulum tuning function, thereby simplifying electrical connection. A pair of mounting tabs are fastened to the frame by respective compliant beams. The accelerometer-gyro may be mounted in an enclosure that maintains a pressure below atmospheric around the accelerometer-gyro.

Abstract: A micromachined silicon tuned accelerometer gyro is formed out of silicon wafers, by micromachining. The top and bottom cover which include driver, forcer, tuning and guard ring elements mounted therein are micromachined in arrays on silicon-on-insulator (SOI) wafers. The center (driver and sensing) element between the top and bottom is micromachined in an array of four inch diameter silicon wafers. The driver and sensing structure is a tuned pendulum attached by flexure joints to a vibrating structure which is in then suspended by a parallelogram dither suspension. The pendulum is tuned by adjusting the magnitude of a d.c. signal to match the natural frequency of the pendulum to the natural frequency of the vibrating structure. The dither suspension flexures of the vibrating structure is uniquely defined and easily machined but yet provides a dither suspension that restrains the vibrating structure within its vibrating plane with no harmonic distortion.

Abstract: An infra-red camera apparatus having a primary mirror assembly formed in a first molded plastic housing; and, a secondary mirror assembly formed in a second molded plastic housing and disposed in front of and in optical alignment with the primary mirror assembly for collecting an image. The first and second housings snap together for assembly of the camera. A focal plane array is disposed in optical alignment with the primary and secondary mirrors for receiving an image focused thereon by the secondary mirror. A substrate is added for supporting the focal plane array and system electronics, which are responsive to images formed on the focal plane array.

Abstract: Micromechanical inertial sensors are formed of a plurality of substantially-planar semiconductor wafers interspersed with oxide layers. The sensitive element is located within an internal aperture of a wafer of the device and is separate therefrom. It is connected to an overlying oxide layer at pedestals that minimize contact area to thereby reduce stray capacitance. Portions of side edges of the various wafers are successively recessed to create topside-exposed wafer sections that permit the grounding of all exposed portions of the device as operational potentials are applied to internal electrodes and sensitive elements.

Abstract: A precision, micro-mechanical semiconductor accelerometer of the differential-capacitor type comprises a pair of etched opposing cover layers fusion bonded to opposite sides of an etched proofmass layer to form a hermetically sealed assembly. The cover layers are formed from commercially available, Silicon-On-Insulator (“SOI”) wafers to significantly reduce cost and complexity of fabrication and assembly. The functional semiconductor parts of the accelerometer are dry-etched using the BOSCH method of reactive ion etching (“RIE”), thereby significantly reducing contamination inherent in prior art wet-etching processes, and resulting in features advantageously bounded by substantially vertical sidewalls.

Abstract: A monolithic angular velocity sensor is formed from a common planar silicon substrate. Sensor element(s) comprising elongated beams is/are suspended within framed apertures formed within the common substrate. Transverse members, or ears, secure the elongated beam(s) to the frame and to the nodal points of the beam(s). Both single beam and multiple beam array sensors may be formed within a common silicon substrate. Orthogonally-directed beams, or arrays of beams, formed with a common substrate, permit angular velocity measurements about two orthogonal axes.

Abstract: A multisensor includes direct rotor coupling. A pair of rotors is mechanically coupled by a torsion bar whose stiffness largely determines the resonant frequency of the counteroscillating rotor pair. The axis of the torsion bar is coincident with the common axis of rotation of the rotors. Piezo bimorphs are fixed to opposed surfaces of radial vanes of the rotors which suspend the torsionally-coupled rotor pair with the case, isolating it from external angular vibration that could interfere with the resonant frequency of the rotor pair subassembly. The bimorphs receive signals for driving the oscillations of the rotors. Taken together, the stiffnesses of the vanes and the torsion bar substantially determine the common resonant frequency of the counteroscillating pair of rotors.

Abstract: A precision, micro-mechanical semiconductor accelerometer of the differential-capacitor type comprises a pair of etched opposing cover layers fusion bonded to opposite sides of an etched proofmass layer to form a hermetically sealed assembly. The cover layers are formed from commercially available, Silicon-On-Insulator ("SOI") wafers to significantly reduce cost and complexity of fabrication and assembly. The functional semiconductor parts of the accelerometer are dry-etched using the BOSCH method of reactive ion etching ("RIE"), thereby significantly reducing contamination inherent in prior art wet-etching processes, and resulting in features advantageously bounded by substantially vertical sidewalls.