Coriolis effect rotation rate sensor and method
First Claim
1. A sensor for sensing the Coriolis effect, comprising:
- a mechanical structure, consisting of a base, a longitudinal member and one or more transverse members, said one or more transverse members being attached at their centers to the ends of said longitudinal member, said one or more transverse members and said longitudinal member lying in a plane, the ends of said one or more transverse members and any end of said longitudinal member not attached to a transverse member being attached to said base,a vibration generator for generating vibrations in said longitudinal member along an x-direction, said x-direction being in the plane of said one or more transverse members and said longitudinal member and parallel to said transverse members, anda vibration sensor for sensing vibrations in said one or more transverse members along a y-direction, said y-direction being in the plane of said one or more transverse members and said longitudinal member and parallel to said longitudinal member,said x-direction vibrations causing said one or more transverse members to vibrate along said y-direction when said base is rotated about a rotation axis that is orthogonal to said x and y-directions as a result of the Coriolis force exerted on said longitudinal member.
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Accused Products
Abstract
A monolithic Coriolis rate sensor includes a first member and a vibration generator that causes the member to vibrate along a first direction. At least one other member is mechanically coupled to the first member so that orthogonal vibrational modes are coupled to the other member when the members are rotated about a rotation axis. The vibrational mode coupling occurs as a result of the Coriolis effect. A vibration sensor is used to sense the orthogonal vibrational modes, the amplitude of which determines the rate at which the members are rotated. In a preferred embodiment, a central and two transverse end members with substantially equal resonant frequencies are mechanically coupled to form an "I"-shaped structure. The center member is vibrated at its resonant frequency, and orthogonal vibrational modes are coupled to the end members when the structure is rotated about a rotational axis that is orthogonal to both vibration directions. A tuning mechanism is also provided that allows for in-situ tuning of the members'"'"' resonant frequencies.
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Citations
21 Claims
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1. A sensor for sensing the Coriolis effect, comprising:
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a mechanical structure, consisting of a base, a longitudinal member and one or more transverse members, said one or more transverse members being attached at their centers to the ends of said longitudinal member, said one or more transverse members and said longitudinal member lying in a plane, the ends of said one or more transverse members and any end of said longitudinal member not attached to a transverse member being attached to said base, a vibration generator for generating vibrations in said longitudinal member along an x-direction, said x-direction being in the plane of said one or more transverse members and said longitudinal member and parallel to said transverse members, and a vibration sensor for sensing vibrations in said one or more transverse members along a y-direction, said y-direction being in the plane of said one or more transverse members and said longitudinal member and parallel to said longitudinal member, said x-direction vibrations causing said one or more transverse members to vibrate along said y-direction when said base is rotated about a rotation axis that is orthogonal to said x and y-directions as a result of the Coriolis force exerted on said longitudinal member. - View Dependent Claims (2)
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3. A rotation sensor, comprising:
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a base, a first member oriented parallel to a y-direction, an oscillation generator positioned to initiate and maintain flexural oscillations in said first member at a driving frequency along an x-axis normal to the first member, the first member having a resonant frequency, the driving frequency being substantially equal to the resonant frequency of the first member, at least one other member oriented parallel to the x-axis and attached at its center to an end of said first member, said at least one other member and said first member lying in a plane, any end of said first member not attached to another member and the ends of said at least one other member being attached to the base, said at least one other member having a resonant frequency substantially equal to the resonant frequency of said first member, said x-direction flexural oscillations inducing a Coriolis force along said y-direction when said base is rotated about a rotation axis that is orthogonal to said x and y directions, thereby causing flexural oscillations along said y-direction in said at least one other member, at least one oscillation sensor for sensing the amplitude of said at least one other member'"'"'s flexural oscillations along said y-direction, and a processor for calculating said rate of rotation about said rotation axis from the amplitude of said flexural oscillations along said y-direction. - View Dependent Claims (4, 5, 6, 7, 8, 9, 10, 11)
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12. A method of measuring rotation rate about a rotation axis, comprising the steps of:
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inducing vibrational oscillations in a first member along an x-direction that is orthogonal to said rotational axis, said first member mechanically coupled to at least one other member that is restrained so that it can only oscillate along a y-direction that is orthogonal to said rotation axis and said x-direction, sensing vibrational oscillations in the at least one other member that are induced along said y-direction by the Coriolis effect, and deriving the rate at which said members are rotated about said rotation axis from the amplitude of said oscillations along said y-direction, the term members denoting said first member and said at least one other member. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20, 21)
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Specification