US 5,850,035 A · Closed loop resonant rotation rate sensor

Abstract

A closed loop sensor that utilizes a piezoelectric structure. In one embodiment, drive/non-control electrodes apply drive voltages to the piezoelectric structure and drive/control electrodes apply drive/control voltages to the piezoelectric structure to cause drive mode displacement of the piezoelectric structure and cancel motion induced pickup mode and quadrature displacements of the piezoelectric structure. In another embodiment, pickup/control electrodes detect a pickup signal from the piezoelectric structure corresponding to the motion induced pickup mode and quadrature displacements and apply a control signal to the piezoelectric structure so as to cancel these displacements. In still another embodiment of the invention, an optical sensing device optically senses the motion induced pickup mode and quadrature displacements and control electrodes apply a control signal to the piezoelectric structure so as to cancel them.

Claims24

Dependent claims

A sensor comprising:

a piezoelectric structure;
a sensor circuit to generate an AC drive signal and an AC control signal;
and
drive electrodes coupled to the sensor circuit and configured on the piezoelectric structure so that (a) all of the drive electrodes together apply the AC drive signal to the piezoelectric structure to cause drive mode displacement of the piezoelectric structure, and (b) at least some of the drive electrodes also together apply the AC control signal to the piezoelectric structure to cancel motion induced pickup mode and quadrature displacements of the piezoelectric structure.

1 more element

A sensor comprising:

a piezoelectric structure;
and
drive electrodes configured on the piezoelectric structure so that (a) drive mode displacement of the piezoelectric structure is caused when all of the drive electrodes together apply an AC drive signal to the piezoelectric structure, and (b) motion induced pickup mode and quadrature displacements of the piezoelectric structure are canceled when at least some of the drive electrodes together also apply an AC control signal to the piezoelectric structure.

A rotation rate sensor comprising:

a piezoelectric tuning fork having drive tines and pickup tines;
and
drive electrodes configured on the piezoelectric structure so that (a) drive mode vibration of the drive tines is caused when all of the drive electrodes together apply an AC drive signal to the drive tines, and (b) motion induced pickup mode and quadrature vibrations of the pickup tines are canceled when at least some of the drive electrodes together also apply an AC control signal to the drive tines.

Dependencies are inferred from the claim text.

Closed loop resonant rotation rate sensor

Life of this patent

Closed loop resonant rotation rate sensor

Life of this patent

Abstract

Claims24