Abstract: Method and apparatus for precise measurement of azimuth. An angular rate sensor is rotated so its sensitive axis periodically aligns with the horizontal component of the earth's spin rate (north). A preferably sinusoidal signal is analyzed with respect to the relative angle of the sensor and a desired direction in order to determine the azimuth of that direction.

Abstract: A printed circuit board (PCB) coil linear actuator is disclosed. The actuator includes a coil assembly and a magnet assembly. The coil assembly includes a plurality of PCB coils electrically connected in series. The PCB coils arranged in a row and adjacent PCB coils are separated by a gap. Each PCB coil includes a low aspect ratio, multi-layer coil member disposed on a board member. The actuator assembly includes a plurality of magnet units arranged in a row, wherein adjacent magnet units are separated by a gap. When the actuator is assembled, the PCB coils arranged in alternating sequence with the magnet units. The PCB coil linear actuator is intended to replace traditional slotted bobbin voice coil actuators (VCAs) and is particularly useful in fast steering mirror (FSM) applications. The PCB coil linear actuator provides many advantages over a VCA of an equivalent motor constant, including improved performance, lower weight and a lower profile.

Abstract: A printed circuit board (PCB) coil linear actuator is disclosed. The actuator includes a coil assembly and a magnet assembly. The coil assembly includes a plurality of PCB coils electrically connected in series. The PCB coils arranged in a row and adjacent PCB coils are separated by a gap. Each PCB coil includes a low aspect ratio, multi-layer coil member disposed on a board member. The actuator assembly includes a plurality of magnet units arranged in a row, wherein adjacent magnet units are separated by a gap. When the actuator is assembled, the PCB coils arranged in alternating sequence with the magnet units. The PCB coil linear actuator is intended to replace traditional slotted bobbin voice coil actuators (VCAs) and is particularly useful in fast steering mirror (FSM) applications. The PCB coil linear actuator provides many advantages over a VCA of an equivalent motor constant, including improved performance, lower weight and a lower profile.

Abstract: An MHD sensor/actuator is provided for generating torque as well as sensing angular displacements around a sense/torque axis. A column of conductive liquid which rotates within a circumferential channel having an inner circumferential surface and outer circumferential surface provides an inertial proof mass, the relative motion of which within the channel generates a torque or represents a sensed displacement about the common axis of the circumferential channel. According to certain embodiments, a cylindrical column of magnets are located coaxially with the circumferential channel to produce a radially oriented magnetic field which is perpendicular to the common axis. According to other embodiments, a magnetic ring is provided coaxially with the circumferential channel to produce a magnetic field in the direction of the common axis.

Abstract: An angular rate sensor which measures submicroradian angular displacements. An MHD sensor is provided having a cylindrical column of conductive fluid, centered about a measurement axis. The magnetic field for the device is generated from permanent magnets and a shunt structure which produces radial magnetic field components through the cylindrical conductive fluid channel. The first electrode contacts an upper end of the cylindrical conductive fluid channel, and a second electrode contacts a lower end of the cylindrical conductive fluid channel. Current produced as a result of an electrostatic potential generated in response to the rotation of the device, flows through a center electrode connecting the first and second electrodes. A transformer winding surrounding the center electrode produces an amplified rate signal from the current flowing between the first and second electrodes.

Abstract: An engine mount actuator having an upper casing open at one end, and connected at an opposite end to an engine mounting bolt. The engine mounting bolt extends within the casing and is supported by a bushing which is in turn laterally supported by an elastomeric isolator disk within the upper casing. A lower casing including a frame mounting bolt at one end, and opened at another end faces the opened end of the upper casing. A mounting flange is supported between the upper and lower casing open ends supports a stator, having first and second toroidal windings which define a circumferential space. A circumferential magnet assembly includes a permanent magnet means supported within the circumferential space, and is coupled to the engine mounting bolt through a spherical bearing. The magnet assembly produces a force against the engine mounting bolt in response to a current through the first and second toroidal windings.

Abstract: Circuit for generating a write disable signal in response to an applied shock force. Angular displacements which indicate an excessive shock force are detected, and signal processed to determine whether or not a displacement will result from the shock force exceeding a threshold level. Low frequency displacements are de-emphasized, while higher frequency displacements in a passband of interest are integrated to obtain a displacement function. The displacement function is compared in a threshold detector with a reference threshold displacement level. Displacements which exceed the established threshold displacement will generate a write disable signal.

Abstract: A magnetohydrodynamic sensor having an annular or circular sense channel containing a conductive liquid proof mass. A radial flow is introduced into the annular channel which, in response to rotation of the device, produces a coriolis force and resulting circumferential velocity of the fluid. An electromagnetic winding produces an alternating electromagnetic field directed perpendicular to the annular channel. First and second electrodes sense a time varying electric potential induced between the center of the annular channel and the circumference of the annular channel. The time varying electrical potential is proportional to the strength of the time varying electric field and rotational velocity of the channel with respect to said proof mass. The transformer connected to the electrodes provides for amplification of the signal representing the rotational velocity of the channel with respect to the proof mass.

Abstract: The present invention relates to a displacement sensor for measuring submicroinch displacements. An LVDT is constructed from an E core having a primary winding on the center pole piece and two secondary windings about two additional pole pieces. The E core device is mounted on a stationary surface opposite a pair of U cores mounted on a translating surface. The U cores are spaced adjacent to each other, having an axis defined coincident with the axis of the E core pole piece which supports the primary winding. This position produces a null voltage from the differentially-connected secondary windings. Linear displacement between the U core and E core results in different coupling between the secondary windings and primary windings. The resulting voltage difference is a measurement of displacement .DELTA.X.

Abstract: Angular motion sensor for sensing angular velocity components at higher frequencies. A first lower case member open at the top thereof supports a magnet therein for establishing a magnetic field oriented parallel to a central axis of the lower case. An insulating surface covers the magnet and a conductive liquid is disposed in a channel defined by the insulating surface and the lower case sidewalls. An upper case having an insulated inner surface including a sidewall structure complementary to the lower case sidewall structure forms a lid for the channel and is insulated from the lower case. The upper case is insulated from the conductive liquid, except at a hole in the insulation lying along a central axis of the lower case and upper case. Relative motion between the liquid mass and upper and lower case structures generates a voltage potential between the upper and lower cases, representing the relative velocity.

Abstract: A magnetohydrodynmic angular rate sensor is described. A housing supports first and second coaxial proof masses in respective annular channels, permitting relative motion between the axis of the proof masses and the housings. First and second magnets associated with each annular channel result in an electric potential being generated across each channel proportional to the relative circumferential velocity between the proof masses and the housing. The annular channels are connected together to form a continuous pumped fluid circuit which introduces a radial flow velocity in each channel. At low rotational frequencies, a circumferential velocity component is induced in the proof masses due to Coriolis acceleration which results in a measurable electrical voltage across the annular channels. The low frequency response of the sensor is therefor extended to lower frequencies.

Abstract: An electronic motion sensor is described, wherein a cavity formed in a case of high flux density material supports a permanent magnet at the bottom. The permanent magnet has a north/south pole orientation in line with the cavity axis. A circular channel is located above, having an axis coincident with the cavity axis and which is filled with mercury. A center contact post is located long the cavity axis in contact with the mercury, extending upwards through the top of the channel. An amplifier circuit supported on a header of high flux density material is placed on top of the channel. The amplifier amplifies the potential difference between the center contact and the case. The header effectively seals the cavity of the case.

Abstract: A solid electrode in the core of an angular motion sensor has a body of conductive fluid confined therein within an annular flux gap between axially spaced magnets. An arrangement of slots in the walls of the electrode modifies the current, induced in the fluid by inertial displacement, into a circumferential component, which is inductively coupled to an output winding from which an output signal is obtained.