Vibrating gyroscope and treatment process
View Patent ↗A vibrating gyroscope has a base and a resonator. The resonator includes a body of generally cylindrical shape terminating in a face. The resonator is capable of vibrating according to a first vibration mode having antinodes distributed on n axes, and a second vibration mode having antinodes distributed on n other axes. The face of the resonator has two piezoelectric assemblies on each axis of the first and of the second vibration modes. Each piezoelectric assembly has at least one piezoelectric element capable of exciting the resonator in vibration and at least one piezoelectric element capable of detecting vibrations of the resonator at the same time.
1. A vibrating gyroscope comprising:
a base comprising vibration control and processing modules; and a resonator comprising a body of generally cylindrical shape terminating in a face, the resonator being capable of vibrating according to a first vibration mode comprising antinodes distributed on n axes, and a second vibration mode comprising antinodes distributed on n other axes,
wherein the face of the resonator comprises on each axis of the first and of the second vibration modes two piezoelectric assemblies (E i ),
each piezoelectric assembly (E i ) comprising at least one piezoelectric element capable of exciting the resonator in vibration and at least one piezoelectric element capable of detecting vibration of the resonator at the same time, and
said face of the resonator further comprises a plurality of through holes for connecting the piezoelectric assemblies (E i ) to said vibration control and processing modules.
2. The gyroscope as claimed in claim 1 , wherein said resonator is capable of vibrating according to a first vibration mode comprising antinodes distributed on two axes (x,y), and a second vibration mode comprising antinodes distributed on two other axes (x 1 ,y 1 ), the face of said resonator comprising on each axis of the first and of the second vibration modes, two piezoelectric assemblies (E i ), each piezoelectric assembly (E i ) at the same time comprising at least one piezoelectric element capable of exciting said resonator in vibration and at least one piezoelectric element capable of detecting vibration of the resonator.
3. The gyroscope as claimed in claim 1 , wherein said piezoelectric assemblies (E i ) are arranged on each axis of the first and of the second vibration modes on either side of a centre of the face of the resonator.
4. The gyroscope as claimed in claim 2 , wherein said piezoelectric assemblies (E i ) are arranged on each axis of the first and of the second vibration modes on either side of a centre of the face of said resonator.
5. The gyroscope as claimed in claim 1 , wherein each said assembly comprises two piezoelectric elements, a piezoelectric element capable of exciting said resonator in vibration and a piezoelectric element capable of detecting vibration of said resonator.
6. The gyroscope as claimed in claim 2 , wherein each said assembly comprises two piezoelectric elements, a piezoelectric element capable of exciting said resonator in vibration and a piezoelectric element capable of detecting vibration of said resonator.
7. The gyroscope as claimed in claim 3 , wherein each said assembly comprises two piezoelectric elements, a piezoelectric element capable of exciting said resonator in vibration and a piezoelectric element capable of detecting vibration of said resonator.
8. The gyroscope as claimed in claim 1 , wherein,
said piezoelectric elements capable of exciting said resonator in vibration are arranged uniformly over a circumference of the face, and
said piezoelectric elements capable of detecting vibration of said resonator are arranged uniformly over the circumference of the face.
9. The gyroscope as claimed in claim 2 , wherein,
said piezoelectric elements capable of exciting said resonator in vibration are arranged uniformly over a circumference of the face, and
said piezoelectric elements capable of detecting vibration of said resonator are arranged uniformly over the circumference of the face.
10. The gyroscope as claimed in claim 3 , wherein,
said piezoelectric elements capable of exciting said resonator in vibration are arranged uniformly over a circumference of the face, and
said piezoelectric elements capable of detecting vibration of said resonator are arranged uniformly over the circumference of the face.
11. The gyroscope as claimed in claim 5 , wherein,
said piezoelectric elements capable of exciting said resonator in vibration are arranged uniformly over a circumference of the face, and
said piezoelectric elements capable of detecting vibration of said resonator are arranged uniformly over the circumference of the face.
12. The gyroscope as claimed in claim 1 , wherein said piezoelectric elements of each assembly comprise distinct elements and/or zones of the same piezoelectric element.
13. The gyroscope as claimed in claim 1 ,
wherein an electrical connection passes through one of the plurality of through holes to connect one or more of said vibration control and processing modules to one of said piezoelectric elements.
14. The gyroscope as claimed in claim 1 , wherein, said through holes are arranged substantially uniformly over a circumference of said face, and said piezoelectric elements are arranged between said through holes.
15. A treatment process in a vibrating gyroscope, wherein the gyroscope comprises:
a base comprising vibration control and processing modules,
a resonator, comprising a body of generally cylindrical shape terminating in a face, the resonator being capable of vibrating according to a first vibration mode comprising antinodes distributed on n axes, and a second vibration mode comprising antinodes distributed on n other axes,
the face of said resonator comprising two piezoelectric assemblies (E i ) on each axis of the first and of the second vibration modes,
each piezoelectric assembly (E i ) comprising at least one piezoelectric element capable of exciting said resonator in vibration and at least one piezoelectric element capable of detecting vibration of the resonator at the same time,
said face of the resonator further comprising a plurality of through holes for connecting the piezoelectric assemblies (E i ) to side vibration control and processing modules,
said process comprising:
measuring vibration of said resonator with said piezoelectric elements, and
combining the measurements of said piezoelectric elements for rejecting parasite vibration modes appearing in said resonator.
16. The process as claimed in claim 15 , wherein said combination of measurements of said piezoelectric elements comprises obtaining for each vibration mode, a treated signal equal to a sum of measurements of the piezoelectric elements located on the antinodes having amplitude of a given sign, minus the sum of measurements of said piezoelectric elements located on the antinodes having amplitude of a sign opposite the given sign, said signs being defined at a given instant of vibration, said treated signal rejecting parasite vibration modes of said resonator.
17. The process as claimed in claim 15 , comprising exciting in vibration the first and/or the second modes via said piezoelectric elements capable of exciting said resonator in vibration arranged on the axes of said mode, said excitation being calibrated from one or more measurements of said piezoelectric elements capable of detecting vibration of said resonator arranged on said axes of said mode, to execute a closed-loop processing.
18. The process as claimed in claim 16 , comprising exciting in vibration the first and/or the second modes via said piezoelectric elements capable of exciting said resonator in vibration arranged on the axes of said mode, said excitation being calibrated from one or more measurements of said piezoelectric elements capable of detecting vibrations of said resonator arranged on said axes of said mode, to execute a closed-loop processing.