Angular rate sensor apparatus
First Claim
1. Improved angular rate sensor apparatus, comprising:
- (a) a pair of matched vibratory piezoelectric angular rate sensor elements, each comprising a drive bender member having a drive resonance frequency and suitable for receiving an energizing drive signal and a sense bender member having a sense resonance frequency operatively connected for movement with said drive bender member and suitable for receiving an actuation stimulus;
(b) means for mounting said pair of angular rate sensor element in close proximity within a distance of 0.008 wavelengths of said drive resonance frequency, for physical vibration in direct opposition to one another about a nodal axis;
(c) drive means operatively connected with said drive bender members of said sensor elements for energizing said sensor elements in a first mode of operation for opposed oscillatory motion relative to one another about said nodal axis;
wherein vibrational forces from said pair of elements cancel along said nodal axis such that transmission thereof through said mounting means is negligible and acoustic noise radiation from said apparatus is reduced;
(d) sensing means independent from said drive means and operatively connected with at least one of said sense bender members for producing a sensed output signal in response to a received actuation stimulus, wherein said stimulus causes a change in movement of said one sense bender member from its first vibrational mode of operation.
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Accused Products
Abstract
An angular rate sensor structure displaying high immunity to noise and feedback vibration is disclosed. Mounting elements (15) support a pair of matched vibratory piezoelectric bender elements (10) in symmetrical opposed alignment about a nodal axis (20). Each vibratory element includes a drive element (10A) and sense element (10B) connected to and for operative movement with the drive element. Resonance drive element (30) moves the vibratory elements (10) in a first mode of movement, in dirct opposition to one another about the nodal axis. The sensing members (10B) detect movement of the vibratory elements in directions other than in the first mode of movement resulting from application of external angular rate forces applied to the vibratory elements.
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Citations
28 Claims
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1. Improved angular rate sensor apparatus, comprising:
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(a) a pair of matched vibratory piezoelectric angular rate sensor elements, each comprising a drive bender member having a drive resonance frequency and suitable for receiving an energizing drive signal and a sense bender member having a sense resonance frequency operatively connected for movement with said drive bender member and suitable for receiving an actuation stimulus; (b) means for mounting said pair of angular rate sensor element in close proximity within a distance of 0.008 wavelengths of said drive resonance frequency, for physical vibration in direct opposition to one another about a nodal axis; (c) drive means operatively connected with said drive bender members of said sensor elements for energizing said sensor elements in a first mode of operation for opposed oscillatory motion relative to one another about said nodal axis;
wherein vibrational forces from said pair of elements cancel along said nodal axis such that transmission thereof through said mounting means is negligible and acoustic noise radiation from said apparatus is reduced;(d) sensing means independent from said drive means and operatively connected with at least one of said sense bender members for producing a sensed output signal in response to a received actuation stimulus, wherein said stimulus causes a change in movement of said one sense bender member from its first vibrational mode of operation. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. Angular rate sensor apparatus comprising:
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(a) a pair of symmetrically matched vibratory piezoelectric angular rate sensor elements, each comprising; (i) a drive bender member having a drive resonance frequency greater than 500 Hertz and suitable for receiving an energizing drive signal; (ii) a sense bender member having a sense resonance frequency and suitable for receiving an external actuation stimulus, wherein said sense resonance frequency exceeds that of said drive resonance frequency; (b) means for mounting said pair of angular rate sensor elements in close proximity for physical vibration in direct opposition to one another about a nodal axis; (c) drive means operatively connected with said drive bender members of said sensor elements for energizing said sensor elements in a first mode of operation for opposed oscillatory motion relative to one another about said nodal axis;
wherein vibrational forces from said pair of elements cancel along said nodal axis such that transmission thereof through said mounting means is negligible; and(d) sensing means independent from said drive means and operatively connected with at least one of said sense bender members for producing a sensed output signal in response to a received actuation stimulus wherein said stimulus causes a change in movement of said one sense bender member from its first vibrational mode of operation. - View Dependent Claims (17)
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18. Angular rate sensor apparatus comprisng:
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(a) a pair of symmetrically matched vibratory piezoelectric angular rate sensor elements, each comprising; (i) a drive bender member having a drive resonance frequency and suitable for receiving an energizing drive signal; (ii) a sense bender member having a sense resonance frequency and suitable for receiving an external actuation stimulus, wherein said sense resonance frequency exceeds that of said drive resonance frequency; (b) means for mounting said pair of angular rate sensor elements in close proximity for physical vibration in direct opposition to one another about a nodal axis; (c) drive means operatively connected with said drive bender members of said sensor elements for energizing said sensor elements in a first mode of operation for opposed oscillatory motion relative to one another about said nodal axis;
wherein vibrational forces from said pair of elements cancel along said nodal axis such that transmission thereof through said mounting means is negligible; and(d) sensing means independent from said drive means and operatively connected with at least one of said sense bender members for producing a sensed output signal in response to a received actuation stimulus, wherein said stimulus causes a change in movement of said one sense bender member from its first vibrational mode of operation;
said sensed output signal having an output response characterized by a useful bandwidth parameter; and(e) wherein said drive and said sense bender members are sized and configured such that the difference between the said resonance frequencies of said sense and said drive members is greater or equal to 4/3 times said bandwidth parameter. - View Dependent Claims (19, 20)
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21. Angular rate sensor apparatus comprising:
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(a) a pair of symmetrically matched vibratory piezoelectric angular rate sensor elements, each comprising; (i) a drive bender member having a drive resonance frequency and suitable for receiving an energizing drive signal; (ii) a sense bender member having a sense resonance frequency and suitable for receiving an external actuation stimulus, wherein said sense resonance frequency exceeds that of said drive resonance frequency; (b) means for mounting said pair of angular rate sensor elements in close proximity for physical vibration in direct opposition to one another about a nodal axis wherein said pair of angular rate sensor elements are mounted in opposed parallel member to one another along sense axes spaced within a distance of 0.008 wavelengths of said drive resonance frequency; (c) drive means operatively connected with said drive bender members of said sensor elements for energizing said sensor elements in a first mode of operation for opposed oscillatory motion relative to one another about said nodal axis;
wherein vibrational forces from said pair of elements cancel along said nodal axis such that transmission thereof through said mounting means is negligible; and(d) sensing means independent from said drive means and operatively connected with at least one of said sense bender members for producing a sensed output signal in response to a received actuation stimulus wherein said stimulus causes a change in movement of said one sense bender member from its first vibrational mode of operation.
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22. An improved angular rate sensor apparatus comprising:
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(a) a support surface; (b) a pair of matched vibratory piezoelectric elements each extending along a sense axis and having substantially identical vibrational response characteristics, said sense axes lying coplanar and parallel to one another; (c) mounting means operatively connected with said vibratory elements for supporting said vibratory elements in cantilevered manner overlying said support surface in closely spaced symmetrical orientation about a common nodal axis;
said vibratory elements being spaced from one another such that their sense axes lie within about 0.008 wavelengths of said drive resonance frequency; and
said mounting means comprising material having a stiffness greater than that of said vibratory elements; and(d) drive means operatively connected with said pair of vibratory elements for causing and maintaining movement of said vibratory elements in a first vibrational mode such that said pair of vibratory elements simultaneously move in direct opposition to one another about said nodal axis;
wherein torsional vibration forces transmitted from said pair of moving vibratory elements to said mounting means cancel along said nodal axis, and acoustic noise radiation from said moving vibratory elements is minimized. - View Dependent Claims (23, 24, 25, 26, 27, 28)
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Specification