Navigational aid for diver

• US 7,333,394 B2
• Filed: 06/22/2005
• Issued: 02/19/2008
• Est. Priority Date: 06/22/2005
• Status: Expired due to Fees

• Current Assignee: Estate Of Albert R. Basilico
• Original Assignee: Albert R. Basilico
• Inventors: Basilico, Albert R.
• Primary Examiner(s): Lobo; Ian J.
• Application Number:
  US11/158,678
• Publication Number:
  US 20060293806A1
• Time in Patent Office: 972 Days
• Field of Search: 367/124, 367/131, 701/21, 701/200
• US Class Current: 367/124
• CPC Class Codes: B63C 11/00 Equipment for dwelling or working underwater; Means for searching for underwater objects composition of chemical substances for use in breathing apparatus A62D9/00; swimming aids or equipment A63B31/00 - A63B35/00; submarines B63G8/00
• CPC Class Codes: B63C 11/02 Divers' equipment
• CPC Class Codes: B63C 2011/021 Diving computers, i.e. portable computers specially adapted for divers, e.g. wrist worn, watertight electronic devices for detecting or calculating scuba diving parameters
• CPC Class Codes: G01C 21/00 Navigation; Navigational instruments not provided for in groups G01C1/00 - G01C19/00 measuring distance traversed on the ground by a vehicle G01C22/00; control of position, course, altitude or attitude of vehicles G05D1/00; traffic control systems for road vehicles involving transmission of navigation instructions to the vehicle G08G1/0968

Abstract

A diver unit computes the direction and distance to a specified target. When the target is obstructed, the diver unit receives navigation assistance data from another diver unit. The navigation assistance data includes direction information that is referenced to a common reference line extending between the two diver units.

Claims

1. A method of underwater navigation, said method comprising:

determining, at a first underwater device, a direction to a target relative to a first angular reference known to the first underwater device;

establishing a reference line between the first and a second underwater device, said reference line forming the base of a reference triangle whose vertices correspond respectively to the first underwater device, the second underwater device and the target;

computing, at the first underwater device, a first included angle of said reference triangle between the reference line and a line extending from the first underwater device to the target based on the direction to the target from the first underwater device;

determining, at the first underwater device, a first distance between the first underwater device and the target;

determining at the first underwater device, a second distance between the first and second underwater device;

computing, at the first underwater device, a third distance from the second underwater device to the target based on the first included angle and the first and second distances; and

transmitting the third distance to the second underwater device to assist the second underwater device in locating the target.

2. The method of claim 1 further comprising:

computing at said first underwater device the direction from the second underwater device to the target; and

sending from the first underwater device to the second underwater device the direction of the second underwater device to the target.

3. The method of claim 2 wherein the direction from the second underwater device to the target is computed relative to the reference line between the first and second underwater devices.

4. The method of claim 2 wherein the direction from the second underwater device to the target is computed relative to an angular reference provided to said first underwater device by said second underwater device.

5. The method of claim 1 further comprising:

computing, at the first underwater device, a second included angle in the reference triangle between the reference line and a line extending from the second underwater device to the target, and

transmitting the second included angie to the second underwater device.

6. The method of claim 5 further comprising computing, at the second underwater device, the direction to target relative to a second angular reference known to the second underwater device based on the second included angle and the direction from the second underwater device to the first underwater device.

7. The method of claim 6 further comprising sending from said second underwater device to said first underwater device, the angle between the reference line and an angular reference used by the second underwater device, and wherein the first underwater device computes the direction relative to said angular reference used by said second underwater device.

8. The method of claim 1 further including transmitting the first included angle to the second underwater device.

9. The method of claim 8 further including computing, at the second underwater device, a second included angle between the reference line and a line extending from the second underwater device to the target.

10. The method of claim 9 further comprising computing, at the second underwater device, the direction to target relative to an angular reference known to the second underwater device based on the second included angle and the direction from the second underwater device to the first underwater device.

11. The method of claim 1 wherein computing the first included angle comprises computing a direction from the first underwater device to the second underwater device, and using the direction to target and the direction to the second underwater device to compute the first included angle.

12. The method of claim 1 wherein determining distance comprises:

receiving a signal; and

computing the distance based on the time of arrival of the signal.

13. The method of claim 1 wherein determining distance comprises:

transmitting a signal;

receiving a reply signal; and

computing the distance based on the time of arrival of the reply signal.

14. The method of claim 1 wherein determining the distance to the target comprises:

receiving a dual tone signal from the target; and

computing the distance based on a difference in signal strength between first and second tones in the dual tone signal.

15. A method of underwater navigation, said method comprising:

determining, at a first underwater device, a direction to a target relative to a first angular reference known to the first underwater device;

establishing a reference line between the first and a second underwater device, said reference line forming the base of a reference triangle whose vertices correspond respectively to the first underwater device, the second underwater device and the target;

computing, at the first underwater device, a first included angle of said reference triangle between the reference line and a line extending from the first underwater device to the target based on the direction to the target from the first underwater device;

determining, at the first underwater device, a first distance between the first underwater device and the target; and

transmitting the first included angle and the first distance to the second underwater device to assist the second underwater device in locating the target.

16. The method of claim 15 further comprising:

determining, at the second underwater device, a second distance between the first and second underwater device;

computing, at the second underwater device, a third distance to the target based on the first included angle and the first and second distances.

17. The method of claim 16 further comprising computing, at the second underwater device, the direction from the second underwater device to the target based on the first included angle, the first distance, and the third distance.

18. The method of claim 15 wherein determining distance comprises:

receiving a signal; and

computing the distance based on the time of arrival of the signal.

19. The method of claim 15 wherein determining distance comprises:

transmitting a signal;

receiving a reply signal; and

computing the distance based on the time of arrival of the reply signal.

20. The method of claim 15 wherein determining the distance to the target comprises:

receiving a dual tone signal; and

computing the distance based on a difference in signal strength between first and second tones in the dual tone signal.