Rotation rate sensor with uncoupled mutually perpendicular primary and secondary oscillations
First Claim
1. A rotational rate gyroscope for detecting rotation thereof about an axis of rotation, comprising the following features:
- a base member;
a primary oscillator adapted to be excited to perform a primary movement which is directed normal to the axis of rotation or about an axis normal to the axis of rotation, respectively;
a secondary oscillator adapted to be caused, by a Coriolis force, to perform a secondary movement which is directed normal to the axis of rotation or about an axis normal to the axis of rotation, respectively, and normal to the primary movement, with major surfaces of the primary oscillator and the secondary oscillator extending substantially in the same plane and the movement of the primary oscillator and/or the movement of the secondary oscillator taking place in this plane;
a first spring means constituting a primary oscillator suspension and holding the primary oscillator so as to be movable with respect to the base member;
a second spring means separate from the first spring means and connecting the primary oscillator to the secondary oscillator and constituting a secondary oscillator suspension, whereinthe primary oscillator suspension is designed such that it permits the primary oscillator to move in the direction of the primary movement, and that it does not permit the primary oscillator to move in the direction of the secondary movement, and the secondary oscillator suspension is designed such that it transfers the primary movement to the secondary oscillator substantially in rigid manner;
that it permits the secondary oscillator to move in the direction of the secondary movement; and
that it substantially prevents a transfer of the secondary movement back to the primary oscillator, wherein the rotation thereof about a first axis can be detected;
wherein the primary oscillator suspension supports the primary oscillator so as to be rotatable with respect to the base member about a second axis, said second axis being substantially normal to the first axis;
wherein the secondary oscillator suspension supports the secondary oscillator so as to be rotatable with respect to the primary oscillator about a third axis, said third axis being substantially normal to the first and second axes;
wherein the torsional strength of the primary oscillator suspension with respect to torsion about the third axis is higher than the torsional strength of the secondary oscillator suspension with respect to torsion about the third axis; and
wherein the secondary oscillator suspension is a torsion spring exhibiting resilience with respect to torsion about the third axis.
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Accused Products
Abstract
A rotational rate gyroscope (100) for detecting rotation thereof comprises a base member (102), a primary oscillator (106) supported by its primary oscillator suspension (104) so as to be movable with respect to the base member (102), and a secondary oscillator (114) supported by a secondary oscillator suspension (112), separate from primary oscillator suspension (104), so as to be movable with respect to the primary oscillator (106). The secondary oscillator suspension (112) is designed such that movement that can be applied to the primary oscillator (106) can be transferred to the secondary oscillator (114), whereas the movement of the secondary oscillator (114) effected by the Coriolis force substantially is not transferred back to the primary oscillator (106). In addition thereto, the major surfaces of the primary oscillator (106) and of the secondary oscillator (114) extend substantially in the same plane, with the movement of the primary oscillator (106) and/or of the secondary oscillator (114) also taking place in this plane.
146 Citations
7 Claims
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1. A rotational rate gyroscope for detecting rotation thereof about an axis of rotation, comprising the following features:
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a base member;
a primary oscillator adapted to be excited to perform a primary movement which is directed normal to the axis of rotation or about an axis normal to the axis of rotation, respectively;
a secondary oscillator adapted to be caused, by a Coriolis force, to perform a secondary movement which is directed normal to the axis of rotation or about an axis normal to the axis of rotation, respectively, and normal to the primary movement, with major surfaces of the primary oscillator and the secondary oscillator extending substantially in the same plane and the movement of the primary oscillator and/or the movement of the secondary oscillator taking place in this plane;
a first spring means constituting a primary oscillator suspension and holding the primary oscillator so as to be movable with respect to the base member;
a second spring means separate from the first spring means and connecting the primary oscillator to the secondary oscillator and constituting a secondary oscillator suspension, wherein the primary oscillator suspension is designed such that it permits the primary oscillator to move in the direction of the primary movement, and that it does not permit the primary oscillator to move in the direction of the secondary movement, and the secondary oscillator suspension is designed such that it transfers the primary movement to the secondary oscillator substantially in rigid manner;
that it permits the secondary oscillator to move in the direction of the secondary movement; and
that it substantially prevents a transfer of the secondary movement back to the primary oscillator, wherein the rotation thereof about a first axis can be detected;
wherein the primary oscillator suspension supports the primary oscillator so as to be rotatable with respect to the base member about a second axis, said second axis being substantially normal to the first axis;
wherein the secondary oscillator suspension supports the secondary oscillator so as to be rotatable with respect to the primary oscillator about a third axis, said third axis being substantially normal to the first and second axes;
wherein the torsional strength of the primary oscillator suspension with respect to torsion about the third axis is higher than the torsional strength of the secondary oscillator suspension with respect to torsion about the third axis; and
wherein the secondary oscillator suspension is a torsion spring exhibiting resilience with respect to torsion about the third axis. - View Dependent Claims (2, 3, 4, 5, 6, 7)
wherein the primary oscillator suspension comprises at least one spring beam that can be deflected by torsion about the second axis. -
3. The rotational rate gyroscope according to claim 1, wherein the secondary oscillator is of substantially rectangular configuration, having a recess in which the primary oscillator having a ring shape is disposed.
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4. The rotational rate gyroscope according to claim 1, wherein the torsion spring is disposed substantially parallel to the third axis, whereas an at least one spring beam of the primary oscillator suspension forms an angle with respect to the third axis.
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5. The rotational rate gyroscope according to claim 1,
wherein at least one sensing electrode is disposed on a side of the base member directed towards the secondary oscillator, said sensing electrode permitting capacitive detection of the rotation of the secondary oscillator about the third axis. -
6. The rotational rate gyroscope according to claim 5, further comprising
means for feeding back an electrical voltage detected by the least one sensing electrode to the same in order to compensate portions of the Coriolis force acting on secondary oscillator. -
7. The rotational rate gyroscope according to claim 6, further comprising
means for applying an electrical voltage to the at least one sensing electrode disposed on the base member for influencing an intrinsic frequency of the secondary oscillator.
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Specification