The Singer Company

Kearfott Guidance & Navigation Corporation

Other

Bo H Ljung

James G Koper

John C Stiles

George R Gamertsfelder

Bernard Friedland

Walter J Krupick

Shri A Kumar

Lincoln S Ferriss

George F Schroeder

Charles J Williams

Timothy H Chang

Hyman Cohen

A single or dual input-axis Coriolis gyro sensor is comprised of a single planar inertia-member (10) connected to a coplanar counter-inertia (13) by a first set of elastic beams (12). The counter-inertia is in turn supported by a second set of coplanar elastic beams (15). The counter-inertia counteracts the reaction forces from the vibrating inertia-member and isolates the inertia-member from external vibrations. The inertia-member is angularly dithered about its center of gravity along an axis perpendicular to the plane. An input rate about a first or second orthogonal axis, locate in the plane of the sensor results in Coriolis moments, causing angular oscillations of the inertia-member. The angular oscillations are restrained by squeeze film damping and voltages applied to electrostatic damping electrodes. The electrode voltages are representative of the angular input rates.

Coriolis gyro sensor

A ring laser gyro system having at least one fixed mirror, and two movable mirror assemblies, for causing a pair of laser beams to counter-rotate therebetween, including amplitude control circuits and a phase control circuit for causing the movable mirror assemblies to sinusoidally oscillate at the same amplitude and frequency, but 180.degree. out of a phase with one-another, to substantially eliminate lock-in.

System for substantially eleminating lock-in in a ring laser gyroscope

A piezoelectric actuator for use in controlling the path length, for example, in a ring laser gyro is made of two piezoelectric discs attached to a metallic structure for exerting a push-pull force thereon to move the metallic structure in an oil can fashion. The piezoelectric actuator is attached to a dual diaphragm mirror assembly in such a way as to impart a strictly linear motion to the mirror assembly without any deliterious rotational effects. The actuator can easily be optimized for varying diaphragm stiffness by adjusting the thickness of the metallic structure to which the piezoelectric discs are attached. The mirror assembly and actuator are designed to minimize the influence of temperature changes on the position of the path length mirror.

Laser light length control assembly for ring laser gyro

A signalling device with a long audible range is described, which is intended for underwater communication between divers. The device consists of a compact and lightweight horn and a rubber bulb. The horn, which works independently from a diver's supply of breathing air, is filled with water and operated by manually squeezing the rubber bulb.

Underwater audible signalling device

In a monolithic gyro assembly having three ring laser gyroscopes each measuring the inertial rotation of an axis, a polyhedron having three facets is used as the beam combiner for the gyroscope. On one of the facets is mounted a fringe detector for providing inertial rotation information for the gyroscope. On the remaining two facets, on either side of the fringe detector facet, are mounted beam power monitoring diodes for measuring the power of the light intensity of the respective beams. The directly measured power from the beams is then used to move a piezoelectric transducer to maintain constant pathlengths for the gyroscope.

Ring laser gyroscope beam combiner for separating and combining

A beam combiner assembly for a ring laser gyroscope is fabricated by positioning two diffraction gratings, mounted onto respective light transmissive substrates, with respect to the output mirror of the gyro block at an offset angle such that an interference fringe pattern is projected onto the photodetector of the ring laser gyroscope. By tilting the diffraction gratings, with respect to the plane of the output mirror, a corrected number of lines per unit length for the diffraction gratings may be effected, thereby providing a beam combiner assembly which is compensated for manufacturing imperfections and other intolerances. Also, the high sensitivity of angular adjustments for the conventional prism beam combiner is overcome.

Beam combiner assembly for ring laser gyroscope

In a precision ring laser gyroscope, to eliminate the effect of an unwanted and unintentional moment generated as a result of a force being applied onto a pathlength controller, a pathlength control assembly is constructed to have optimal hub and diaphragm portions such that the mirror element mounted thereto does not tilt in response to the unintentional moment.

Method of constructing a moment insensitive pathlength control mirror

A ring laser gyro path length controller has a cup-like fixture which mounts a piezoelectric actuator and is bonded directly to the gyro block. A mirror assembly is concentrically located within the fixture and is independently mounted to the gyro block thereby enabling independent assembly and disassembly of the fixture and the assembly. Diaphragm sections of the assembly are coaxially positioned and connected to a diaphragm section of the fixture so that bidirectional displacement of the assembly may occur and the moment generated by the actuator results in an axial deflection force on the assembly. A strip of material having a high coefficient of expansion is mounted to the piezoelectric actuator to augment the deflection force as temperature increases thereby reducing the power demands of the actuator.

Path length controller for ring laser gyroscope

Apparatus is disclosed for retaining an electrically fired getter inside a ring laser gyroscope. A groove is formed in a plate, which is hermetically sealed to a hole in the ring laser gyroscope block. The cylindrically shaped getter is placed longitudinally in the groove such that the getter contacts the groove along only two lines. A mousetrap shaped spring preloads the getter against the groove so as to prevent acceleration forces and vibrations from causing pieces of the getter, heater coil or wire to break loose.

Retainer for electrically fired getter

A pathlength controller is provided for a three-axis, cube-shaped ring laser gyroscope assembly having three four-sided gyroscopes with six mirrors, including three movable mirrors and three fixed mirrors, wherein the controller connects between the three movable mirrors and the three fixed mirrors, and is adapted to change the pathlength of one gyroscope without changing the pathlengths of the other two gyroscopes.

Pathlength controller for three-axis ring laser gyroscope assembly

A pathlength controller for a ring laser gyroscope with a modulated mirror is disclosed where a voltage bias is applied to the modulation signal to prevent starting the ring laser gyroscope at a point where it operates with two equal longitudinal modes.

Pathlength controller for ring laser gyroscope

A resilient serpentine shaped tungsten wire is formed to match a short wire section to hold a ring laser gyroscope getter. The getter-holder assembly is positioned within a stepped oblong bore so that the getter is in firm contact with the bore surface at two points. This prevents resonances of the getter or holder that might otherwise destroy the getter while subjected to vibrations.

Ring laser gyroscope getter-holder

A monolithic ring laser gyroscope is formed by six mirrors mounted to the respective center of each face in a cube. Bores in the cube interconnect each of the mirrors. Three orthogonal planes are defined within the cube, each of which contains a laser cavity. Accordingly, three orthogonal beam paths exist, each responsive to rotational inputs about three orthogonal axes.

Monolithic three axis ring laser gyroscope

This solderless electrical connector for an electrical cable consists of a helical spring and loop joined together to form a ring. The helical spring provides a snug fit on a matching cylindrical post while offering strain relief protection for the electrical cable, which is routed through the helix of the spring.

Ring laser gyro cathode connection

An electromechanically dithered ring laser gyroscope includes a beam combiner utilizing optical fibers instead of conventional optics. This permits a beam measuring photodetector and associated electronics to be positioned outside the gyroscope or its enclosure. The invention further includes a dither compensator using optical fibers thereby replacing sensitive electronic or optical dither compensating components.

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Wayne, NJ, United States of America

Bo H Ljung