Rotational vibration gyroscope

• US 5,377,544 A
• Filed: 12/19/1991
• Issued: 01/03/1995
• Est. Priority Date: 12/19/1991
• Status: Expired due to Term

• Current Assignee: Freescale Semiconductor, Inc. (NXP Semiconductors NV)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Dunn, William C.
• Primary Examiner(s): CHAPMAN JR, JOHN E
• Application Number:
  US07/810,043
• Time in Patent Office: 1,111 Days
• Field of Search: 73/505, 73/510, 73/517 AV
• US Class Current: 73/504.08
• CPC Class Codes: G01C 19/5719 using planar vibrating masses driven in a translation vibration along an axis
• CPC Class Codes: G01P 15/18 in two or more dimensions

Abstract

A rotor affixed to a central mounting post by helical springs for oscillatory rotary movement about the post. The post defining a Z axis and the sensing capacitors adjacent the rotor defining X and Y axes. The rotor, helical springs and post being formed of polysilicon in a single semiconductor process step,

Claims

1. A rotational vibration gyroscope comprising:

a base with a generally planar upper surface;

a mounting post fixedly attached to the base and defining a first axis;

a mass including a generally disk shaped layer of semiconductor material lying in a plane parallel to and spaced from the planar upper surface of the substrate and positioned in a plane perpendicular to the post;

springs affixed at one end to the post and at another end to the mass, and mounting the mass for oscillatory rotary movement about the post;

oscillatory motion driving apparatus mounted adjacent to the mass for causing the mass to move in an oscillatory rotary motion about the first axis; and

sensing apparatus, positioned adjacent to the mass and defining second and third axes mutually perpendicular to each other and to the first axis, for sensing movement of the disk about the third axis in response to movement of the gyroscope about the second axis, the sensing apparatus including first plates positioned in parallel to and adjacent the mass for sensing movement about the third axis in response to movement of the gyroscope about the second axis and second plates positioned in parallel to and adjacent the mass for sensing movement about the second axis in response to movement of the gyroscope about the third axis.

2. A rotational vibration gyroscope comprising:

a base with a generally planar upper surface;

a mounting post fixedly attached to the base and defining a first axis;

a mass including a generally disk shaped layer of semiconductor material lying in a plane parallel to and spaced from the planar upper surface of the substrate and positioned in a plane perpendicular to the post;

springs affixed at one end to the post and at another end to the mass, and mounting the mass for oscillatory rotary movement about the post;

oscillatory motion driving apparatus mounted adjacent to the mass for causing the mass to move in an oscillatory rotary motion about the first axis, the driving apparatus including plates positioned parallel to and spaced from the mass which when properly pulsed produce oscillatory rotational motion of the mass; and

sensing apparatus, positioned adjacent to the mass and defining second and third axes mutually perpendicular to each other and to the first axis, for sensing movement of the disk about the third axis in response to movement of the gyroscope about the second axis.

3. A rotational vibration gyroscope as claimed in claim 2 wherein the plates are formed from a layer of semiconducting material.

4. A rotational vibration gyroscope comprising:

a base with a generally planar upper surface;

a mounting post fixedly attached to the base and defining a first axis;

a mass including a generally disk shaped layer of semiconductor material lying in a plane parallel to and spaced from the planar upper surface of the substrate and positioned in a plane perpendicular to the post;

springs affixed at one end to the post and at another end to the mass, and mounting the mass for oscillatory rotary movement about the post;

oscillatory motion driving apparatus mounted adjacent to the mass for causing the mass to move in an oscillatory rotary motion about the first axis; and

sensing apparatus, positioned adjacent to the mass and defining second and third axes mutually perpendicular to each other and to the first axis, for sensing movement of the disk about the third axis in response to movement of the gyroscope about the second axis, the sensing apparatus including plates positioned parallel to and spaced from each major surface of the mass and further positioned adjacent the third axis to form a plurality of capacitors, the combined capacitance of which is an indication of movement of the mass about the third axis.

5. A rotational vibration gyroscope as claimed in claim 4 wherein the plates are formed from a layer of semiconducting material.

6. A rotational vibration gyroscope comprising:

a mounting post fixedly attached to a base and defining a first axis;

a mass positioned in a plane perpendicular to the post;

springs affixed at one end to the post and at another end to the mass, and mounting the mass for oscillatory rotary movement about the post, the springs including a plurality of helical springs each connected from the post to the mass;

oscillatory motion driving apparatus mounted adjacent to the mass for causing the mass to move in an oscillatory rotary motion about the first axis; and

sensing apparatus, positioned adjacent to the mass and defining second and third axes mutually perpendicular to each other and to the first axis, for sensing movement of the rotor about the third axis in response to movement of the gyroscope about the second axis.

7. A rotational vibration gyroscope comprising:

a substrate having a generally planar surface;

a central mounting post fixedly attached to the planar surface of the substrate, generally perpendicular to the planar surface of the substrate and defining a first axis;

a disk shaped mass having a central opening therethrough and positioned coaxially about the post in a plane parallel to the planar surface of the substrate;

generally helical springs affixed at one end to the post and at another end to the mass, and mounting the mass for oscillatory rotary movement about the post;

oscillatory motion driving apparatus mounted adjacent to the mass for causing the mass to move in an oscillatory rotary motion about the first axis; and

sensing capacitors, positioned adjacent the mass and defining second and third axes mutually perpendicular to each other and to the first axis, for sensing movement about the third axis in response to movement of the gyroscope about the second axis.