Abstract:
Multi-axis micromachined accelerometer which, in some disclosed embodiments, has a proof mass suspended above a substrate for movement in response to acceleration along first and second axes, a first detection electrode connected to the proof mass and constrained for movement only along the first axis, and a second detection electrode connected to the proof mass and constrained for movement only along the second axis. In another embodiment, the proof mass is also movable in response to acceleration along a third axis which is perpendicular to the substrate, and a third detection electrode is mounted on the substrate beneath the proof mass for detecting movement of the proof mass in response to acceleration along the third axis. In other embodiments, two proof masses are mounted above a substrate for torsional movement about an axis perpendicular to the substrate in response to acceleration along a first axis and for rotational movement about a second axis parallel to the substrate in response to acceleration along second axis perpendicular to the substrate, a first detector having input electrodes connected to the proof masses and constrained for movement only along the first axis for detecting acceleration along the first axis, and detection electrodes mounted on the substrate beneath the proof masses for detecting rotational movement of the proof masses and acceleration along the second axis.
Abstract:
Rate sensor comprising a plurality of generally planar masses, a drive axis in the plane of each of the masses, means for driving the masses to oscillate about the drive axes, an input axis perpendicular to the drive axes, sense axes perpendicular to the drive axes and the input axis, means mounting the masses for torsional movement about the sense axes in response to Coriolis forces produced by rotation of the masses about the input axis, and means responsive to the torsional movement about the sense axis for monitoring rate of rotation about the input axis.
Abstract:
Rate sensor comprising two generally planar proof masses, means for driving the masses to oscillate in phase opposition about parallel drive axes in the planes of the masses, an input axis perpendicular to the drive axes, sense axes perpendicular to the drive axes and the input axis, means mounting the masses for torsional movement about the sense axes in response to Coriolis forces produced by rotation of the masses about the input axis, means constraining the two masses for anti-phase movement about both the drive axes and the sense axes, sensing frames coupled to the masses for movement in response to the torsional movement of the masses about the sense axes, and means responsive to movement of the sensing frames for monitoring rate of rotation about the input axis.
Abstract:
A MEMS silicon inertial sensor formed of a mass that is supported and constrained to vibrate in only specified ways. The sensors can be separately optimized from the support, to adjust the sensitivity separate from the bandwidth. The sensor can sense three dimensionally, or can only sense in a single plane. Vibration cancellation may be provided.
Abstract:
Shock-resistant enclosure having a housing (11) to which a fragile element is rigidly mounted, and a plurality of discrete shock absorbing elements (18, 19, 21, 22) projecting from the housing in different directions for receiving impacts, which would otherwise strike the housing. In some embodiments, the shock absorbing elements include elastomeric bumpers, which are formed integrally with a gasket (16) that provides a seal between two sections of the housing. In others, they include plastic fenders or springs (37), which are formed integrally with and of the same material as the housing.
Abstract:
Conductive plastic resistance element having particles of conductive material embedded therein and projecting therefrom for reducing variations in contact resistance in potentiometric device in which the element is employed. The element is made by processing carbon powder, resin, solvent and conductive phases to form a paste, applying the paste to a substrate, and curing the paste to drive off the solvent and form a film, with the conductive phases rising to the surface of the film and becoming embedded therein.
Abstract:
Cross-monitoring sensor system and method in which a plurality of sensors (68, 69) each having a sensing element, circuitry for processing signals from the sensing element, an output interface for delivering processed signals, and an auxiliary input to which signals from another device can be input for processing and delivery by the output interface. Signals from each of the sensors are applied to the auxiliary input of another one of the sensors, and signals from the output interfaces of the sensors are compared to verify integrity of the system.
Abstract:
A stack assembly (100) is disclosed of the type used in linear brushless DC motors, the stack assembly having a base portion (106), a plurality of teeth (102) extending from the base portion and about which the windings can be positioned, and in which the plurality of teeth are spaced apart from each other so as to define slot openings at ends of and between adjacent teeth, and magnetic material (112) shaped and positionable to enclose one or more of the slot openings between adjacent teeth. Also disclosed is a mounting bracket (120) positionable along the back iron of the stack assembly and shaped so that the ends of the mounting bracket (124) engage with the ends of the stack assembly.
Abstract:
Rate sensor comprising two generally planar proof masses, means for driving the masses to oscillate in phase opposition about parallel drive axes in the planes of the masses, an input axis perpendicular to the drive axes, sense axes perpendicular to the drive axes and the input axis, means mounting the masses for torsional movement about the sense axes in response to Coriolis forces produced by rotation of the masses about the input axis, means constraining the two masses for anti-phase movement about both the drive axes and the sense axes, sensing frames coupled to the masses for movement in response to the torsional movement of the masses about the sense axes, and means responsive to movement of the sensing frames for monitoring rate of rotation about the input axis.
Abstract:
Inertial measurement system and method in which a base is rotated about an input axis in accordance with a rotation to be measured, rotation about the input axis is sensed with one or more angular rate sensors, fixed bias offset is cancelled by dithering the sensors about an axis perpendicular to their sensing axes to vary the orientation of the sensing axes relative to the base in an oscillatory manner, and signals from the sensors are demodulated at the dithering frequency.