Giant magnetoresistance based gyroscope

• US 20060055551A1
• Filed: 08/28/2003
• Published: 03/16/2006
• Est. Priority Date: 11/17/2000
• Status: Active Grant

• Current Assignee: David P. Fries
• Original Assignee: David P. Fries
• Inventors: Fries, David P.
• Granted Patent: US 7,113,104 B2
• Time in Patent Office: Days
• US Class Current: 340/672
• CPC Class Codes: G01D 5/145 influenced by the relative movement between the Hall device and magnetic fields see G01R33/06
• CPC Class Codes: G01D 5/2451 Incremental encoders G01D5/2454 takes precedence
• CPC Class Codes: G01P 13/00 Indicating or recording presence, absence, or direction, of movement electric switches H01H; counting moving objects G06M7/00
• CPC Class Codes: G01P 15/105 by magnetically sensitive devices
• CPC Class Codes: G11B 5/40 Protective measures on heads, e.g. against excessive temperature G11B5/31 takes precedence; protection against wear G11B5/255 ; protective structure of the head: see under structures, e.g. G11B5/3106

Abstract

A gyroscope (10) for determining rate of rotation includes a giant magnetoresistor (GMR) (14) attached to a mass (12) oscillating along a first axis. When the gyroscope (10) is rotated, the mass (12) also oscillates along a second axis perpendicular to the first axis. A magnetic element (16), which includes of a strip of magnetic bits (18), is disposed along the first axis, the second axis, or both. The magnetic bits (18) supply discrete magnetic fields. The GMR (14) changes in electrical resistance when exposed to these magnetic fields. A voltage sensor (20) and processor (34) are then utilized to calculate the rate of rotation.

Claims

1. A gyroscope (10) for determining rate of rotation, said gyroscope (10) comprising:

a mass (12) that oscillates with oscillations that vary as said gyroscope (10) is rotated;

a magnetic element (16) producing a magnetic field;

a giant magnetoresistor (GMR) (14) operatively connected to said mass (12) for changing in electrical resistance in response to changes in the magnetic field produced by said magnetic element (16);

a voltage sensor (20) operatively connected to said GMR (14) for sensing a voltage across said GMR (14);

said magnetic element (16) including a strip of magnetic bits (18) providing discrete magnetic regions disposed linearly relative to one another along a path;

said mass (12) and said strip of magnetic bits (18) being supported for movement relative to one another along said path to produce digital signals from said voltage sensor (20).

2. A gyroscope (10) as set forth in claim 1 further comprising a drive circuit (24) for vibrating said mass.

3. A gyroscope (10) as set forth in claim 1 further comprising a tuning fork (30) for supporting said GMR (14).

4. A gyroscope (10) as set forth in claim 1 further comprising a processor (34) operatively connected to said voltage sensor (20) for computing the rate of rotation based on said digital signals produced by said voltage sensor (20).

5. A gyroscope (10) as set forth in claim 1 further comprising a plurality of biasing members (22) for supporting said mass (12).

6. A gyroscope (10) as set forth in claim 5 wherein said plurality of biasing members (22) is comprised of a plurality of springs (22).

7. A gyroscope (10) for determining rate of rotation comprising:

a mass (12) that oscillates with oscillations that vary as said gyroscope (10) is rotated;

a magnetic element (16) producing a magnetic field;

a giant magnetoresistor (GMR) (14) operatively connected to said mass (12) for changing in electrical resistance in response to changes in the magnetic field produced by said magnetic element (16);

a voltage sensor (20) operatively connected to said GMR (14) for sensing the voltage across said GMR (14);

said magnetic element (16) including a first strip of magnetic bits (18) providing discrete magnetic regions disposed linearly relative to one another along a first path and a second strip of magnetic bits (18) providing discrete magnetic regions disposed linearly relative to one another along a second path; and

said mass (12) and said strips of magnetic bits (18) being supported for movement relative to one another along said paths to produce digital signals from said voltage sensor (20).

8. A gyroscope (10) as set forth in claim 7 further comprising a drive circuit (24) for oscillating said mass (12).

9. A gyroscope (10) as set forth in claim 7 further comprising a tuning fork (30) for supporting said GMR (14).

10. A gyroscope (10) as set forth in claim 7 further comprising a processor (34) operatively connected to said voltage sensor (20) for computing the rate of rotation based on said digital signals produced by said voltage sensor (20).

11. A gyroscope (10) as set forth in claim 7 further comprising a plurality of biasing members (22) for supporting said mass (12).

12. A gyroscope (10) as set forth in claim 11 wherein said plurality of biasing members (22) is comprised of a plurality of springs (22).