Societe De Fabrication D'instruments De Mesure

Societe De Fabrication D'instruments De Mesure (s.f.i.m.)

Jean-Thierry Audren

Charlie Pelletier

A gyroscope constructed in accordance with the present invention includes a flywheel (220) which can oscillate with at least two degrees of freedom about a central position in which the flywheel axis is aligned with the axis of a drive shaft (200), the flywheel being held radially and rotated relative to the body (100) of the apparatus. The gyroscope also includes a set of electrodes (101 to 104) for electrostatically controlling the position or for detecting the position of the flywheel. The electrodes are fixed relative to the body and face corresponding conducting surfaces of the flywheel. In accordance with the invention, the gyroscope further includes a rigid spinning casing (250) which encloses the flywheel in such a manner as to interpose a dielectric surface between the corresponding conducting surfaces of the flywheel and each electrode, the casing being fixed to the flywheel drive shaft but not having any degrees of freedom in oscillation relative to the body other than being free to spin.

Gyroscope apparatus rotating casing for a rotor

A flexibly suspended gyroscope apparatus comprises a fixed body (100), a rotary drive shaft (200) supported in said body, and a flywheel (220) mounted on said drive shaft by a rotary joint (222). The joint serves to retain the flywheel radially and to transmit rotary drive thereto, while leaving said flywheel free to oscillate with two degrees of freedom about a central position in which the axis of the flywheel is aligned with the axis of the drive shaft. The flywheel is also free for axial translation with one degree of freedom. Axial support means (101, 102, 103, 104) are provided for applying an axial force to the flywheel by electrostatic or electromagnetic induction, and axial position detector means are provided for detecting the axial position of the flywheel, said support means being servo controlled by said detector means to maintain the flywheel in a predetermined axial position. Advantageously the same or similar means also apply precession torques to the flywheel, thereby constituting a rate gyro.

Gyroscope apparatus, in particular a flexibly suspended and

An electrostatic motor is constituted by a capacitor (10) having relatively movable electrodes (11, 12) separated by a variable gap (13). The control circuit includes a DC source (60) which is servo-controlled to current measurement means (20) and integrator means (30) for calculating the charge on the capacitor plates and for maintaining said charge constant (Q.sub.0). By applying servo control to keep the charge constant, the force on the plates is independent of the variable value of the gap (14). The charge is preferably on/off switched with a pulse width modulation ratio that is a function of the force which is to be applied.

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Les Ulis, France

Jean-Thierry Audren