Geomagnetic orientation sensor, means, and system

• US 5,394,029 A
• Filed: 02/17/1993
• Issued: 02/28/1995
• Est. Priority Date: 02/17/1993
• Status: Expired due to Fees

• Current Assignee: Billy R. Smith, John C. Gay
• Original Assignee: Billy R. Smith, John C. Gay
• Inventors: Smith, Billy R., Gay, John C.
• Primary Examiner(s): Callahan, Timothy P.
• Assistant Examiner(s): TRAN, TOAN V
• Application Number:
  US08/018,872
• Time in Patent Office: 741 Days
• Field of Search: 307/309, 364/449, 364/453, 364/454, 364/559, 33/361, 33/356, 73/178 R
• US Class Current: 327/511
• CPC Class Codes: G01C 17/28 Electromagnetic compasses with north seeking magnetic elements and having electric pick-offs G01C17/26
• CPC Class Codes: G01R 33/0206 Three-component magnetometers

Abstract

The Geomagnetic Orientation Sensor is a device used to determine the orientation of objects with respect to the magnetic field surrounding the earth. The sensor may also be used to determine orientation with respect to a local magnetic field, a local attenuation of the earth'"'"'s magnetic field, or used as a pointer to track moving magnetic potentials. The device incorporates three mutually orthogonal Hall effect generator pairs, the output voltage differentials of which are directly proportional to the magnetic field intensity and direction relative to each generator pair. A set of three differential amplifier circuits detect and amplify the small voltages induced by the geomagnetic field. The resulting voltages, V_X, V_Y, and V_Z, are multiplied by a constant to acquire three orthogonal angular displacement values with a range of 0 degrees to 180 degrees. The device is further arranged with an analog to digital converter for subsequent analysis of the three indicative voltages by a digital computer, and a computer program that performs the necessary calculations to convert the 180 degree maximum angular displacement values to pitch, roll, and yaw numbers with a maximum value of 360 degrees. A second computer program performs the various calculations necessary to describe and display the orientation of remote objects on a computer display. The preceding embodiment may be referred to as a computer input device.

Claims

1. A geomagnetic orientation sensor apparatus for generating three sets of voltage differentials representing the angular displacement of the geomagnetic flux with respect to said sensor apparatus comprising:

(a) a plurality of Hall voltage generating means arranged in three groups such that each of said groups is mutually orthogonal.

(b) a set of electrical connections to each of said groups by which a plurality of opposing currents may flow in opposite directions through each of said groups.

(c) electrical connections to each of said groups such that three sets of voltage differentials may be detected by an electronic amplifying means.

2. The geomagnetic orientation sensor of claim 1 wherein said Hall voltage generating means are made of semiconductive material.

3. The geomagnetic orientation sensor of claim 1 wherein said electronic amplifying means includes:

three differential amplifiers;

first of said differential amplifiers, connected to first of said groups;

second of said differential amplifiers, connected to second of said groups;

third of said differential amplifiers, connected to third of said groups.

4. The geomagnetic orientation sensor of claim 1 further including a protective enclosure.

5. The geomagnetic orientation sensor of claim 4 wherein said protective enclosure is rectangular shaped.

6. The geomagnetic orientation sensor of claim 5 wherein said protective enclosure is made of epoxy.

7. A computer input device comprising a geomagnetic orientation sensing means for generating three sets of orthogonal voltage differentials representative of the angular displacement of the geomagnetic flux with respect to said sensing means comprising:

(a) a plurality of Hall voltage generating means arranged in three groups such that each of said groups is mutually orthogonal to the others.

(b) a set of electrical connections to each of said groups such that a plurality of opposing currents may flow through each of said groups.

(c) electrical connections to each of said groups such that three sets of voltage differentials may be detected by an electronic amplifying means.

(d) an interfacing means of connecting said electronic amplifying means to a computer.

8. The computer input device of claim 7 wherein said interfacing means is a high speed analog to digital converter.

9. The computer input device of claim 7 wherein said electronic amplifying means includes:

three differential amplifiers;

first of said differential amplifiers connected to first of said groups;

second of said differential amplifiers, connected to second of said groups;

third of said differential amplifiers connected to third of said groups.

10. The computer input device of claim 7 wherein said Hall voltage generating means are made of semiconductive material.

11. The computer input device of claim 7 further including a protective enclosure.

12. The computer input device of claim 11 wherein said protective enclosure is rectangular shaped.

13. The computer input device of claim 12 wherein said protective enclosure is made of epoxy.

14. A computer input device for controlling graphics on a computer graphic display comprising:

(a) a protective enclosure;

(b) a geomagnetic orientation sensor means, within the enclosure, for sensing the magnitude and direction of angular displacement of the geomagnetic flux for a continuous range of angles with respect to three orthogonal planes passing therethrough and for generating electrical signals representative thereof, and including a plurality of Hall voltage generating means arranged in three groups such that each of said groups are mutually orthogonal, and a set of electrical connections to each of said groups by which a plurality of opposing currents may flow in opposite directions through each of said groups;

(c) interface means, coupled to the sensor means, for translating said electrical signals into digital graphics control signals for transmission to a computer.

15. The computer input device of claim 14 wherein said Hall voltage generating means are made of semiconductive material.