Angular rate sensor system

An angular rate sensor comprising:

• (a) a single crystal of quartz having two substantially parallel sections, each of said sections being provided at its center with a first gap, leaving a small bridge between the two portions of each section, each portion forming a tine of a tuning fork;
• (b) said sections being interconnected at each end by an interconnecting member forming an output shaft, each of said members being separated from its associated section by a second gap leaving a small bridge between each member and its associated section, said gaps controlling said tine inertia and frequency of said sensor, whereby the dimensions of said gaps and of said portions and the masses of said sections, portions and members determine the resonant frequency of said tines and the frequency of an output signal indicative of the angular rate of motion to which said sensor is subjected.

An angular rate sensor system comprising:

• (a) a single crystal resonant structure exhibiting piezoelectric properties, said structure having at least two vibrating elements, each of said vibrating elements comprising two tines and a common shaft, said tines and shaft being disposed in a plane, said common shaft serving as an output shaft, said single crystal structure providing a balanced resonant sensor responsive solely to a component of angular motion about the longitudinal axis of said output shaft, causing a torsional deflection on said output shaft
• (b) driving means coupled to said tines for causing them to vibrate at a drive frequency and
• (c) output means coupled to said output shaft for detecting a piezoelectric signal representative of the angular rate of motion about said axis to which said system is subjected.

An angular rate sensor comprising:

• a single crystal of piezoelectric material having at least two tines symmetrically disposed in a plane about a common shaft, which are vibrated in first and second opposing directions in said plane, and
• electrodes mechanically connected to said single crystal for piezoelectrically measuring stresses caused by the movement of said tines in third and fourth opposing directions orthogonal to said plane caused by rotation of said vibrated tines.

An angular rate sensor comprising:

• a single crystal of piezoelectric material formed as first and second tines disposed symmetrically about a common axis
• first and second sets of electrodes attached to said first and second tines of said single crystal of piezoelectric material for subjecting said tines to oscillating voltages, thereby causing said tines to vibrate in a plane and
• a third set of electrodes attached to said single crystal of piezoelectric material to detect piezoelectric voltages generated by said material caused by movement of said tines in directions orthogonal to said plane when said material is rotated.

A gyroscope comprising:

• a single crystal of piezoelectric material having first and second tines
• a driver for piezoelectrically driving said tines to move said tines along first paths and
• a sensor for sensing rotation of said piezoelectric material by piezoelectrically detecting stress caused by the tendency of said tines to continue moving along said first paths.

A gyroscope comprising:

• a single crystal of piezoelectric material having a first portion comprising first and second tines which are driven along first and second paths, said first and second paths disposed in a common plane and
• a sensor mechanically connected to a second portion of said single crystal to piezoelectrically measure stresses caused in said second portion of said single crystal by rotation of said tines of said single crystal which forces said tines to move along a path other than said first path.

A method of sensing rotation comprising the steps of:

• vibrating the tines of a single, tuning fork-shaped crystal having piezoelectric properties in a first plane and
• sensing piezoelectric voltages generated by stresses within said vibrating single crystal resulting from the movement of said tines in directions orthogonal to said plane caused by the rotation of said single crystal.

A method of sensing rotation of a gyroscope which includes a single crystal of piezoelectric material having at least first and second tines comprising a tuning fork with said two tines and a common shaft disposed in a plane, the method comprising the steps of:

• electrically driving tines of said single crystal of piezoelectric material to move the tines of said single crystal along a first path;
• and
• piezoelectrically detecting stress in said single crystal caused by the tendency of said tines to continue moving along said first path, thereby detecting rotation of said single crystal of piezoelectric material.