The Charles Stark Draper Laboratory, Inc.

Byong-Ho Ahn

Raymond Carroll

Marc Steven Weinberg

Kaplesh Kumar

Dilip K Das

Michele S Sapuppo

Anthony M Moscaritolo

Kenneth Fertig

Philip J Gilinson, Jr

Howard L Watson

A system for electronically tuning and suppressing 2N rectification torques in a dynamically tuned free rotor gyroscope with a universal hinge, or a plurality of universal hinges. The system includes means to adjust the frequency of the drive shaft of the gyroscope to a speed such that the rotor precession due to direct elastic restraint torques is eliminated. In addition, the system includes means for measuring the two degree of freedom angular deviations of the principal axis of the rotor with respect to the gyroscope case, as well as the angular deviations of the shaft spin axis relative to the gyroscope case. The sensed angular deviations of both the rotor and shaft drive a torque generator which produces a torque on the rotor for nulling torque due to angular vibrations of the drive shaft with respect to the rotor. The controlled phasing and gain of the nulling torque provides both average bending compliance tuning and suppression of the 2N rectification.

System for electronically tuning and suppressing 2N rectification

A single vibration sensor having the capability of sensing vibration along three rotational axes as well as three translational axes and exhibiting consistent dynamics over a wide frequency range. The sensor includes an elongated mass formed of a generally rigid material suspended in a fluid within a housing. The exterior surface of the mass is spaced from the interior surface of the housing to permit limited freedom of motion of the mass within the housing. The mass is provided with multiaxial radial and axial electromagnetic suspensions, and is typically supported by a fluid within the housing. Rotational positioning is provided by a signal generator, torque generator combination. Vibration is sensed by additive or differential measurements of current changes in the coils of different axes of the suspensions or electromagnetic signal and torque generator combinations. The sensor is conveniently implemented as a single degree of freedom inertial gyroscope without the gyroscope wheel and adapted to permit sensing of current changes in coils provided to achieve suspension or suspension and signal and torque generation functions.

Multiaxial vibration sensor

Process for the formation of precipitation hardened beryllium-nickel, beryllium-iron, and beryllium-cobalt alloys and cermets for structural and bearing use respectively in precision instruments and such alloys and cermets. A beryllium-nickel, -iron, or -cobalt high solute solution at elevated temperature is rapidly cooled to provide a readily machined solid solution. After machining, the alloy is reheated to an intermediate temperature under controlled conditions where precipitation hardening occurs through limited precipitate cluster formation. A cermet is formed in the process with the addition of a ceramic material to the beryllium alloy in the initial steps.

Age hardened beryllium alloy and cermets

A torque reaction test system for evaluating the performance characteristics of a test motor by detecting its inertial reaction torque to acceleration and deceleration of the rotor. In one embodiment a test motor, typically at a final assembly stage and contained within a housing where it is inaccessible, is mounted in a rotatable fixture and the torque reaction of the test motor when accelerated and decelerated is obtained. The torque reaction is plotted against time or speed. A torque balance loop provides a feedback current which maintains the test motor housing within the fixture at a predetermined point of rotation and which provides an indication of torque reaction. A further embodiment provides a dynamometer in which a test motor is driven by a drive motor for a rapid run-up time and the torque response characteristics are plotted as a function of time or speed to provide nondestructive determination of system parameters.

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Wayland, MA, United States of America

Byong-Ho Ahn