Global positioning using planetary constants

• US 7,822,549 B2
• Filed: 05/05/2006
• Issued: 10/26/2010
• Est. Priority Date: 05/05/2005
• Status: Expired due to Fees

• Current Assignee: Nytell Software LLC (Intellectual Ventures LLC)
• Original Assignee: Aprolase Development Co LLC (Intellectual Ventures LLC)
• Inventors: Itzhak, Sapir
• Primary Examiner(s): ARTHUR JEANGLAUDE, GERTRUDE
• Application Number:
  US11/429,468
• Publication Number:
  US 20100211351A1
• Time in Patent Office: 1,635 Days
• Field of Search: 701/213, 701/214, 701/216, 701/219, 701/221, 701/225, 359/429, 359/430
• US Class Current: 701/213
• CPC Class Codes: G01C 21/04 by terrestrial means G01C21/24, G01C21/26 take precedence

Abstract

The disclosed invention is generally comprised of a device capable of measuring the vector sum of the centripetal acceleration of the rotation of the Earth (or that of any other planet in a planetary system) around its axis (a_rot) and the centripetal acceleration of the planet'"'"'s revolution in its orbit around the Sun (a_rev) and a method for performing the same using the measured physical data to calculate the latitude and longitude of the device on a surface. Measurements are taken by stepping accelerometers through different axis to determine centripetal acceleration, reading the output of the accelerometers and reading the angular disposition of the accelerometers using encoders and calculating the latitude and longitude from the measured data.

Claims

1. A location measurement device comprising:

a reference member having at least two degrees of freedom and coupled to a frame, wherein the reference member includes a rotatable end;

an arm pivotably coupled to the rotatable end and having an axis;

a rotatable head rotatably coupled to the arm, wherein the rotatable head includes a first inertial measurement device configured to measure acceleration parallel to the axis of the arm and a second inertial measurement device configured to measure acceleration perpendicular to the axis of the arm; and

a computation module configured to determine a position of the reference member relative to a body based on at least one measurement of the first inertial measurement device while the frame is stationary.

2. The device of claim 1, wherein one end of the reference member comprises a weighted end, and wherein the device further comprises a locking mechanism configured to lock the reference member to the frame.

3. The device of claim 1, wherein the computation module is further configured to:

align the reference member to a gravitational vector associated with the body;

rotate the reference member and the arm to a first position where an acceleration reading of the first inertial measurement device is maximized; and

determine the position of the reference member relative to the body based on the acceleration reading.

4. The device of claim 1, wherein the first inertial measurement device and the second inertial measurement device comprise an accelerometer.

5. The device of claim 4, wherein the accelerometer is one of a piezoelectric, piezoresistive, or a microelectromechanical system (MEMS) accelerometer.

6. The device of claim 1, wherein the rotatable end further comprises at least one first encoder and a first motor, and wherein the rotatable head further comprises at least one second encoder and a second motor.

7. A location measurement device comprising:

a reference member configured to align with a gravitational vector of a body; and

a first inertial measurement device configured to align with an equivalent vector including a rotation vector and a revolution vector of the body;

wherein an acceleration reading of the first inertial measurement device and the alignment of the first inertial measurement device are associated with a position of the reference member relative to the body.

8. The device of claim 7, further comprising a second inertial measurement device configured to align normal to a plane defined by the rotation vector and the revolution vector.

9. The device of claim 8, further comprising a computation module that is configured to:

determine a first revolution vector based on a first measurement by the second inertial measurement device at a first time and a second measurement by the second inertial measurement device at a second time;

determine a first rotation vector based on the first revolution vector; and

determine a latitude of the reference member based on the first rotation vector.

10. The device of claim 9, wherein the computation module is further configured to determine a longitude of the reference member based on acceleration characteristics of a reference longitude.

11. The device of claim 10, wherein the computation module is further configured to determine a hemisphere of the latitude by comparing the first rotation vector and the first revolution vector to the gravitational vector when a longitude vector of the device relative to the body is pointed opposite of the direction of the first revolution vector.

12. The device of claim 7, further comprising a computation module configured to:

measure the equivalent vector for at least three-quarters of a rotation of the body;

determine a first midway equivalent vector and a second midway equivalent vector, wherein the first midway equivalent vector occurs halfway between a maximum equivalent vector and a minimum equivalent vector during the rotation, and wherein the second midway equivalent vector occurs halfway between the minimum equivalent vector and the maximum equivalent vector during the rotation;

determine the revolution vector based on the first midway equivalent vector and the second midway equivalent vector;

determine a first rotation vector based on the revolution vector; and

determine a latitude of the device based on the first rotation vector.

13. The device of claim 12, further comprising an altimeter, wherein the determination of the latitude is based, at least in part, on a reading of the altimeter.

14. A location measurement device comprising:

a reference member;

an arm pivotably mounted to the reference member; and

an accelerometer coupled to the arm; and

a computation module configured to;

align the reference member to a gravitational vector associated with a body;

at a first time, pivot the arm to a first position where a first acceleration reading of the accelerometer is maximized;

at a second time, pivot the arm to a second position where a second acceleration reading of the accelerometer is maximized; and

determine a position of the reference member relative to the body based on the first acceleration reading and second acceleration reading.

15. The device of claim 14, wherein the reference member is configured to be adjusted by a compensation angle that corrects for rotational and revolution effects of the body.

16. The device of claim 14, further comprising a vibration compensator associated with the reference member.

17. The device of claim 14, wherein the computation module comprises a look-up table including acceleration characteristics associated with latitudes and longitudes of the body.

18. A method of locating a device, the method comprising:

determining, at a first time, a first normal vector normal to a rotation vector and a revolution vector of a body;

determining, at a second time, a second normal vector normal to the rotation vector and the revolution vector of the body;

determining the revolution vector based on the first normal vector and the second normal vector;

determining a first rotation vector based on the revolution vector; and

determining a latitude of the device based on the first rotation vector.

19. The method of claim 18, further comprising:

determining a first angle between the second normal vector and a vector normal to the rotation vector and a gravitational vector;

comparing the first angle to a model of longitudinal angles associated with a known location; and

determining a longitude of the device based on the comparison.

20. The method of claim 18, wherein said determining a first normal vector and said determining a second normal vector each comprise aligning a first inertial measurement device with an equivalent vector including the rotation vector and the revolution vector and aligning a second inertial measurement device normal to a plane defined by the rotation vector and the revolution vector.

21. A method of locating a device, the method comprising:

measuring an equivalent vector including a rotation vector and a revolution vector for at least three-quarters of a rotation of a body;

determining a first midway equivalent vector and a second midway equivalent vector, wherein the first midway equivalent vector occurs halfway between a maximum equivalent vector and a minimum equivalent vector during the rotation, and wherein the second midway equivalent vector occurs halfway between the minimum equivalent vector and the maximum equivalent vector during the rotation;

determining the revolution vector based on the first midway equivalent vector and the second midway equivalent vector;

determining a first rotation vector based on the revolution vector; and

determining a latitude of the device based on the first rotation vector.

22. The method of claim 21, wherein said measuring an equivalent vector comprises aligning a first inertial measurement device with the equivalent vector.

23. The method of claim 21, further comprising:

comparing a time of occurrence of at least one of the maximum equivalent vector or the minimum equivalent vector with a known reference; and

determining a longitude of the device based on the comparison.

24. The method of claim 23, wherein the time of occurrence is determined using a clock synchronized with a clock associated with the known reference.

25. The method of claim 21, further comprising determining a hemisphere of the latitude by comparing the first rotation vector and the revolution vector to the gravitational vector when a longitude vector of the device relative to the body is pointed in the direction opposite of the direction of the first revolution vector.