Bae Systems, Inc.

Atlantic Inertial Systems, Inc.

Stewart McWilliam

Christopher Paul Fell

Rebecka Eley

Colin H J Fox

Atanas Popov

A vibrating structure angular rate sensor comprises a substrate; a plurality of supporting structures fixed to the substrate; an annular member flexibly supported by the plurality of supporting structures; a drive system arranged to apply a periodic driving force such that the annular memberoscillates, in use, in a primary mode of vibration at a resonant frequency f, with an amplitude of motion that generates a restoring force from the plurality of supporting structures; and a pick-off system arranged to determine the amplitude of motion of a secondary mode of vibration at a resonant frequency f, in which oscillation of the annular memberis induced by the Coriolis force resulting from an angular rate experienced by the sensor. In use, the restoring force has a non-linear relationship with the amplitude of motion and a number p of supporting structures is selected such that f=f.

Angular rate sensor arranged to determine amplitude of motion of secondary mode of vibration at resonant frequency

A two axis gyroscope including a substantially planar vibratory resonator () having a substantially ring or hoop-like structure with inner and other peripheries extending around a common axis, carrier mode drive () for causing the resonator () to vibrate in a cosn&#x3b8; vibration mode, carrier mode pick-off () for sensing movement of the resonator () in response to the carrier mode drive (), X-axis response mode pick-off () for detecting movement of the resonator in response to rotation about the X-axis, X-axis response mode drive () for nulling said motion, y-axis response mode pick-off () for detecting movement of the resonator in response to rotation about the y-axis, y-axis response mode drive () for nulling said motion, and a support () for flexibly supporting the resonator () and for allowing the resonator to vibrate relative to the support () in response to the carrier mode drive () and to applied rotation, wherein the support () comprises only L legs, where, when L is even:=2, andwhere, when L is odd:where K is an integer, L&#x3e;2 and N is the carrier mode order.

Vibratory gyroscopic rate sensor

A three axis rate sensor includes a substantially planar vibratory resonator having a substantially ring or hoop-like structure with inner and outer peripheries extending around a common axis, drive means for causing the resonator to vibrate in a Cos 2&#x3b8; vibration mode, carrier mode pick-off means for sensing movement of the resonator in response to the applied drive z-axis response mode, pick-off means for detecting movement of the resonator in response to rotation about the z-axis, z-axis response mode drive means for nulling said motion, x-axis response mode pick-off mean for detecting movement of the resonator in response to rotation about the x-axis, x-axis response mode drive means for nulling said motion, y-axis response mode pick-off mean for detecting movement of the resonator in response to rotation about the y-axis, y-axis response mode drive means for nulling said motion, and support means for flexibly supporting the resonator and for allowing the resonator to vibrate relative to the support means in response to the drive means and the applied rotation wherein the support means comprises only L support beams, where L&#x2260;2, and K=0, 1, 2 or 3. For example there may be three, five, six or seven support beams.

A three axis sensor including a substantially planar vibrator resonator or having a substantially ring or hoop like structure with inner and outer peripheries e tending around a common axis, drive means for causing the resonator to vibrate in an in lane cos 2&#x3b8; vibration mode, carrier mode pick-off means for sensing movement of the resonator in response to said drive means, pick-off means for sensing in plane sin 2&#x3b8; resonator motion induced by rotation about the z-axis, drive means for nulling said motion, pick-off means for sensing out of plane sin 3&#x3b8; resonator motion induced by rotation about the x-axis, drive means for nulling said motion, pick-off means for sensing out of plane cos 3&#x3b8; resonator motion induced by rotation about the y-axis, drive means for nulling said motion, and support means for flexibly supporting the resonator and for allowing the resonator to vibrate relative to the support means in response to the drive means and to applied rotations, wherein the support means comprises only L support beams, where L&#x2260;2&#xd7;3and J=0, 1 or 2 and K=0 or 1 with L&#x3c;24.

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Nottingham, United Kingdom

Stewart McWilliam