Monolithic quartz resonator accelerometer

Claim 2

A monolithic quartz resonator accelerometer comprising: a monolithic quartz sensing structure including: a frame; a resonator structure connected to said frame; and a proof mass support structure within said frame and supported by said resonator structure; a proof mass fixed to said support structure; and electrode means on said resonator structure for driving said resonator structure at a vibration frequency which varies as a function of the acceleration of said proof mass.

Claim 3

The accelerometer of claim 1 further including quartz support means for securing said sensing structure.

Claim 4

The accelerometer of claim 2 in which said support means includes two support plates encompassing said frame.

Claim 5

The acceleromater of claim 3 in which said support plates are fixed to said frame.

Claim 6

The accelerometer of claim 3 in which said support plates include means for clamping said resonator structure proximate said support structure.

Claim 7

The accelerometer of claim 2 in which said support means has the same crystallographic orientation as said monolithic quartz sensing structure.

Claim 8

The accelerometer of claim 1 further including means for energizing said electrode means to vibrate said resonator structure.

Claim 9

The accelerometer of claim 7 in which said means for energizing includes means for establishing the vibration frequency of said resonator.

Claim 10

The accelerometer of claim 8 further including means, responsive to said means for establishing, for determining the acceleration of said proof mass.

Claim 11

The accelerometer of claim 9 in which said means for determining includes means for calculating the change in vibration frequency of said resonator as said proof mass is accelerated.

Claim 12

The accelerometer of claim 9 further including means for sensing the temperature of said quartz sensing structure.

Claim 13

The accelerometer of claim 11 in which said quartz sensing structure is integral with said means for sensing temperature.

Claim 14

The accelerometer of claim 11 in which said means for sensing temperature includes a temperature-sensitive resonator structure and means for vibrating said temperature-sensitive resonator structure.

Claim 15

The accelerometer of claim 13 in which said means for sensing temperature further includes means for resolving the vibration frequency of said temperature-sensitive resonator structure.

Claim 16

The accelerometer of claim 14 in which said means for determining the acceleration of said proof mass is responsive to said means for resolving for determining a temperature-corrected acceleration.

Claim 17

The accelerometer of claim 1 in which said proof mass includes a quartz member having the same crystallographic orientation as said monolithic quartz sensing structure.

Claim 18

The accelerometer of claim 1 in which said resonator structure includes two resonator elements aligned along a common longitudinal axis.

Claim 19

The accelerometer of claim 1 in which said resonator structure includes an elongated beam member.

Claim 20

The accelerometer of claim 18 in which said elongated member includes a double tuning fork structure.

Claim 21

The accelerometer of claim 1 in which said monolithic quartz sensing structure is rotated less than 10 degrees from the quartz Z axis.

Claim 22

A monolithic quartz resonator accelerometer, comprising: a monolithic quartz sensing structure including: a frame; a proof mass support structure within said frame; and a pair of axially aligned elongated beam resonator structures interconnecting said frame and said support structure; a proof mass fixed to said support structure; a first quartz support plate on one side of said sensing structure and a second quartz support plate on the opposite side of said sensing structure for securing said sensing structure, said support plates having the same crystallographic orientation as said sensing structure; at least one of said support plates having hinge means projecting toward said sensing structure proximate said resonator structures for clamping said resonator structures proximate said support structure; electrode means on said resonator structures; means for energizing said electrode means to vibrate said resonator structures at a frequency dependent on the force applied to said resonator structures along said alignment axis; means, responsive to said means for energizing, for determining the difference in vibration frequency of said resonator structures; and means, responsive to said means for determining, for establishing the acceleration of said proof mass in the direction of said alignment axis.

Claim 23

A monolithic quartz resonator accelerometer, comprising: a monolithic quartz sensing structure including: a frame; a proof mass support structure within said frame; and a pair of axially aligned elongated beam resonator structures interconnecting said frame and said support structure; a proof mass fixed to said support structure; a first quartz support plate on one side of said sensing structure and a second quartz support plate on the opposite side of said sensing structure for securing said sensing structure, said support plates having the same crystallographic orientation as said sensing structure; at least one of said support plates having hinge means projecting toward said sensing structure proximate said resonator structures for clamping said resonator structures proximate said support structure; electrode means on said resonator structures; means for energizing said electrode means to vibrate said resonator structures at a frequency dependent on the force applied to said resonator structures along said alignment axis; means, responsive to said means for energizing, for determining the difference in vibration frequency of said resonator structures; and means, responsive to said means for determining, for establishing the acceleration of said proof mass in the direction of said alignment axis.