Vibratory angular rate sensor system
First Claim
1. A vibratory angular rate sensor system comprising:
- (a) a mounting, .[.frame of substantially rectangular configuration having a substantially rectangular opening.]. said .[.frame.]. .Iadd.mounting .Iaddend.consisting of a piezoelectric material .[.of Z-cut crystalline quartz.].;
(b) a first pair and a second pair of tines .Iadd.forming a tine structure.Iaddend., .[.disposed in said opening.]. said first pair forming vibrating drive tines.[.,.]. vibrating toward and away from each other .Iadd.in a plane of motion .Iaddend.and said second pair of tines forming vibrating output tines.[.,.]. vibrating in .Iadd.directions perpendicular to said plane of motion .[.opposite directions up and down.].;
(c) .[.a stem.]. .Iadd.interconnecting means .Iaddend.interconnecting said first and second .[.pair.]. .Iadd.pairs .Iaddend.of tines .Iadd.to effect an interdependency between the first and second pairs of tines whereby motion in one pair of tines is transferred to the other pair of tines.Iaddend., the tines of each pair being disposed parallel to each other and corresponding tines of .[.both pairs.]. .Iadd.each pair .Iaddend.being disposed along a common axis;
(d) means including .[.two pairs of.]. input electrodes in contact with the first pair of tines for exciting said tines substantially at the resonant frequency thereof, .[.said input electrodes being in the X-Y and Y-Z planes of said wafer.].;
(e) means including .[.two pairs of.]. output electrodes .[.disposed.]. in contact with the second pair of tines .[.in the Y-Z plane.]. for deriving an output signal representative of the angular rate experienced by said system, the flexural .Iadd.resonant .Iaddend.frequency of said first pair of tines being .[.lower than.]. .Iadd.different from .Iaddend.that of said second pair of tines and(f) .[.a plurality of bridges,.]. .Iadd.bridge means .Iaddend.integral with said .[.frame.]. .Iadd.mounting .Iaddend.and connected to said .[.stem.]. .Iadd.means interconnecting said first and second pairs of tines for supporting said first and second pairs of tines on said mounting.Iaddend..
0 Assignments
0 Petitions
Accused Products
Abstract
.[.A vibratory angular rate sensor system preferably consists of a Z-cut quartz plate forming a mounting frame with a rectangular opening. Within the opening are mounted two pairs of tines. Each pair of tines is parallel to each other, one pair forming the drive tines and the other pair the output tines. Each corresponding set of two tines is disposed along the same axis having a common stem or base. The tines are secured by four bridges integral with the frame and connected to the stem. The arrangement is such that the pair of input tines vibrates in opposition to each other, while the pair of output tines vibrates with one tine going up while the other moves downwardly. As a result, the angular rate sensors drive frequency and the structural torque frequency are unequal. Therefore large displacements of the stem are unnecessary..]. .Iadd.An angular rate sensor having a support structure and first and second forks each lying in a plane each having an axis of symmetry with each fork having first and second spaced apart tines. The first and second forks are mechanically coupled to each other to provide a dual fork structure. A mount is provided for mounting the dual fork structure on the support structure. Energy is coupled into the first fork of the dual fork structure to cause vibratory motion of the tines of that fork in the plane of the fork. Vibratory motion of the tines of the other fork in a direction normal to the plane of the other fork is sensed to provide a angular rate about the measure axis of symmetry of the first fork. The mounting serves to isolate the dual fork structure from the support structure..Iaddend.
55 Citations
8 Claims
-
1. A vibratory angular rate sensor system comprising:
-
(a) a mounting, .[.frame of substantially rectangular configuration having a substantially rectangular opening.]. said .[.frame.]. .Iadd.mounting .Iaddend.consisting of a piezoelectric material .[.of Z-cut crystalline quartz.].; (b) a first pair and a second pair of tines .Iadd.forming a tine structure.Iaddend., .[.disposed in said opening.]. said first pair forming vibrating drive tines.[.,.]. vibrating toward and away from each other .Iadd.in a plane of motion .Iaddend.and said second pair of tines forming vibrating output tines.[.,.]. vibrating in .Iadd.directions perpendicular to said plane of motion .[.opposite directions up and down.].; (c) .[.a stem.]. .Iadd.interconnecting means .Iaddend.interconnecting said first and second .[.pair.]. .Iadd.pairs .Iaddend.of tines .Iadd.to effect an interdependency between the first and second pairs of tines whereby motion in one pair of tines is transferred to the other pair of tines.Iaddend., the tines of each pair being disposed parallel to each other and corresponding tines of .[.both pairs.]. .Iadd.each pair .Iaddend.being disposed along a common axis; (d) means including .[.two pairs of.]. input electrodes in contact with the first pair of tines for exciting said tines substantially at the resonant frequency thereof, .[.said input electrodes being in the X-Y and Y-Z planes of said wafer.].; (e) means including .[.two pairs of.]. output electrodes .[.disposed.]. in contact with the second pair of tines .[.in the Y-Z plane.]. for deriving an output signal representative of the angular rate experienced by said system, the flexural .Iadd.resonant .Iaddend.frequency of said first pair of tines being .[.lower than.]. .Iadd.different from .Iaddend.that of said second pair of tines and (f) .[.a plurality of bridges,.]. .Iadd.bridge means .Iaddend.integral with said .[.frame.]. .Iadd.mounting .Iaddend.and connected to said .[.stem.]. .Iadd.means interconnecting said first and second pairs of tines for supporting said first and second pairs of tines on said mounting.Iaddend.. - View Dependent Claims (2, 3, 4)
-
- 7. fork structure is formed of a piezoelectric material. .Iaddend. .Iadd.10. A rate sensor as in claim 9 wherein said mounting means is formed of a piezoelectric material. .Iaddend. .Iadd.11. A rate sensor as in claim 7 wherein said dual fork structure and said mounting means are formed of a single sheet of single crystal piezoelectric material. .Iaddend. .Iadd.12. A rate sensor as in claim 7 wherein said mounting means supports the dual fork structure in a region intermediate the first and second forks. .Iaddend. .Iadd.13. A rate sensor as in claim 12 wherein said mounting means in combination with the dual fork structure has a resonant frequency which is substantially the same frequency as said vibratory motion of the
Specification