Abstract: A vibrating structure gyroscope includes an annular resonator arranged to vibrate in a plane in response to electrostatic driving forces and a set of capacitive drive electrodes arranged to apply a voltage creating an electrostatic driving force to excite a primary cos n? resonance along a primary axis at a primary frequency fP, such that Coriolis forces, resulting from an angular rate applied about an out-of-plane axis, induce a secondary cos n? resonance along a secondary axis at a secondary frequency fS. The gyroscope also includes digitally-controlled first and second sets to creating a static electrostatic balancing.

Abstract: A vibrating structure gyroscope includes an annular resonator arranged to vibrate in a plane in response to electrostatic driving forces and a set of capacitive drive electrodes arranged to apply a voltage creating an electrostatic driving force to excite a primary cos n? resonance along a primary axis at a primary frequency fP, such that Coriolis forces, resulting from an angular rate applied about an out-of-plane axis, induce a secondary cos n? resonance along a secondary axis at a secondary frequency fS. The gyroscope also includes digitally-controlled first and second sets to creating a static electrostatic balancing.

Abstract: An angular velocity sensor or gyroscope has a ring and a primary drive transducer arranged to cause the ring to oscillate in a primary mode substantially at the resonant frequency of the primary mode of the ring. A primary control loop receives primary pick-off signals from the primary pick-off transducer and provides primary drive signals to the primary drive transducer so as to maintain resonant oscillation of the ring. The primary control loop includes a demodulator arranged to determine the amplitude of the fundamental frequency of the primary pick-off signals and a demodulator arranged to determine the amplitude of the second harmonic frequency of the primary pick-off signals and a drive signal generator arranged to produce the primary drive signals with an amplitude that is dependent on a ratio of the amplitude of the second harmonic frequency of the primary pick-off signal over the amplitude of the fundamental frequency of the primary pick-off signal as derived by a divider.

Abstract: An angular velocity sensor or gyroscope has a ring and a primary drive transducer arranged to cause the ring to oscillate in a primary mode substantially at the resonant frequency of the primary mode of the ring. A primary control loop receives primary pick-off signals from the primary pick-off transducer and provides primary drive signals to the primary drive transducer so as to maintain resonant oscillation of the ring. The primary control loop includes a demodulator arranged to determine the amplitude of the fundamental frequency of the primary pick-off signals and a demodulator arranged to determine the amplitude of the second harmonic frequency of the primary pick-off signals and a drive signal generator arranged to produce the primary drive signals 116 with amplitude that is dependent on a ratio of the amplitude of the second harmonic frequency of the primary pick-off signal over the amplitude of the fundamental frequency of the primary pick-off signal as derived by a divider.

Abstract: A method for reducing bias error in a Vibrating Structure Gyroscope having a vibrating structure, a primary drive for putting the vibrating structure into carrier mode resonance, a primary pick-off device for sensing carrier mode motion, a secondary pick-off for sensing response mode vibration of the vibrating structure in response to applied rotation rate, a secondary drive for applying a force to control the response mode motion, closed loop primary control loops for maintaining a fixed amplitude of motion at the primary pick-off device, for maintaining the drive frequency at the resonance maximum, and secondary control loops for maintaining a null at the secondary pick-off device.

Abstract: A method for reducing bias error in a Vibrating Structure Gyroscope having a vibrating structure (1), primary drive means (2), for putting the vibrating structure (1) into carrier mode resonance, primary pick-off means (3) for sensing carrier mode motion, secondary pick-off means (10) for sensing response mode vibration of the vibrating structure (1) in response to applied rotation rate, secondary drive means (16) for applying a force to control the response mode motion closed loop primary control loops for maintaining a fixed amplitude of motion at the primary pick-off means (3) for maintaining the drive frequency at the resonance maximum, and secondary control loops for maintaining a null at the secondary pick-off means (10).

Abstract: Apparatus for measuring variation in scalefactor from a predetermined value for a vibrating structure gyroscope has a vibrating structure (R), a fixed primary and a fixed secondary drive means (1, 13) for putting and maintaining the vibrating structure (R) in vibrating resonance, a fixed primary and a fixed secondary pick off means (2, 6) for detecting vibration of the vibrating structure (R), with the drive and pick off means (1, 13, 2, 6) being located radially around the vibrating structure (R), quadrature component and real component loop systems (7, 8), automatic gain control and phase locked loop systems (5, 22), a sin/cos pick off resolver (38) for receiving signals from the primary and secondary pick off means (2, 6) and for outputting signals to the quadrature component and real component loop systems (7, 8) and to the automatic gain control and phase locked loop systems (5, 22), a sin/cos drive resolver (37) for receiving output signals from the quadrature component and real component loop systems (