Wave power

• US 7,371,136 B2
• Filed: 05/18/2006
• Issued: 05/13/2008
• Est. Priority Date: 01/20/2006
• Status: Active Grant

• Current Assignee: Liquid Robotics, Inc. (The Boeing Co.)
• Original Assignee: Liquid Robotics, Inc. (The Boeing Co.)
• Inventors: Kiesow, Kurt A. F., Hine, Derek L., Burcham, Robert, Rizzi, Joseph D., Stutz, William A., Hine, Roger G.
• Primary Examiner(s): Olson; Lars A.
• Application Number:
  US11/436,447
• Publication Number:
  US 20070173141A1
• Time in Patent Office: 726 Days
• Field of Search: 440/3, 440/9, 440/13, 440/17, 440/18, 440/19, 440/20, 114/293
• US Class Current: 440/9
• CPC Class Codes: B63B 2035/006 Unmanned surface vessels, e.g. remotely controlled
• CPC Class Codes: B63H 1/36 swinging sideways, e.g. fishtail type
• CPC Class Codes: B63H 19/02 by using energy derived from movement of ambient water, e.g. from rolling or pitching of vessels
• CPC Class Codes: B63H 19/04 propelled by water current
• CPC Class Codes: B63H 2025/028 using remote control means, e.g. wireless control; Equipment or accessories therefor
• CPC Class Codes: B63H 2025/045 making use of satellite radio beacon positioning systems, e.g. the Global Positioning System [GPS]
• CPC Class Codes: B63H 25/04 automatic, e.g. reacting to compass
• CPC Class Codes: Y02T 70/5236 Renewable or hybrid-electric solutions

Abstract

A wave-powered water vehicle includes a surface float, a submerged swimmer, and a tether which connects the float and the swimmer, so that the swimmer moves up and down as a result of wave motion. The swimmer includes one or more fins which interact with the water as the swimmer moves up and down, and generate forces which propel the vehicle forward. The vehicle, which need not be manned, can carry communication and control equipment so that it can follow a course directed by signals sent to it, and so that it can record or transmit data from sensors on the vehicle.

Claims

1. A wave-powered water vehicle which comprises

(1) a float,

(2) a swimmer, and

(3) a tether connecting the float and the swimmer;

the float, swimmer and tether being such that, when the vehicle is in still water,

(i) the float is on or near the surface of the water,

(ii) the swimmer is submerged below the float, and

(iii) the tether is under tension;

the swimmer comprising

(2a) a swimmer body having a longitudinal axis, and

(2b) a fin system which

(a) is secured to the body,

(b) comprises a fin, and

(c) when the vehicle is in wave-bearing water,

(i) has a configuration which changes as a result of the wave motion, and

(ii) interacts with the water to generate forces which tend to move the swimmer in a horizontal direction;

the vehicle having one or more of the following characteristics;

(A) the fin system comprises a fin which rotates about an axis of rotation, the axis of rotation having a spatial relationship to the swimmer body which changes when the vehicle is in wave-bearing water;

(B) the fin system comprises a fin having a leading edge which comprises (i) a relatively rigid central section which has a fixed spatial relationship with the swimmer body, and (ii) relatively deformable outboard sections;

(C) the fin system comprises two generally laminar fins, each of which rotates about an axis of rotation generally aligned with the longitudinal axis of the swimmer body;

(D) the swimmer body has a substantially rigid fore section, a midsection which is relatively flexible in the vertical plane, and a substantially rigid aft section;

(E) the swimmer comprises a swimmer body comprising a central tubular housing and wave-actuated fins which extend either side of the housing; and

(F) the swimmer body comprises a generally tubular housing and vertical fin surfaces respectively adjacent to the leading end and the trailing end of the swimmer body.

2. A water vehicle according to claim 1 which has characteristic (A), and wherein the fin is a generally laminar fin and the axis of rotation is generally transverse to the longitudinal axis of the swimmer body.

3. A water vehicle according to claim 1 wherein the fin is generally laminar and elastically deformable.

4. A water vehicle according to claim 3 wherein the fin is the sole elastic component of the fin system.

5. A wave-powered water vehicle which comprises

(1) a float,

(2) a swimmer,

(3) a tether connecting the float and the swimmer, and

(4) a computer system;

the float, swimmer and tether being such that, when the vehicle is in still water,

(i) the float is on or near the surface of the water,

(ii) the swimmer is submerged below the float, and

(iii) the tether is under tension;

the swimmer, when the vehicle is in wave-bearing water, interacting with the water to generate forces which tend to move the float horizontally;

the float comprising a satellite-referenced position sensor;

the swimmer comprising (a) a horizontal sensor which senses direction in a horizontal plane, and (b) a steering actuator; and

the computer system (a) being linked to the position sensor, the horizontal sensor and the steering actuator, and (b) containing, or being programmable to contain, instructions to control the steering actuator in response to signals received from the position sensor and the horizontal sensor, or in response to signals received from a sensor on the vehicle.

6. A water vehicle according to claim 5 wherein the horizontal sensor is a magnetic compass.

7. A water vehicle according to claim 5 wherein the swimmer has a center of gravity, and the tether is attached to the swimmer substantially vertically above the center of gravity.

8. A water vehicle according to claim 5 wherein the float has a center of buoyancy, and tether is attached to the float substantially vertically below the center of buoyancy.

9. A water vehicle according to claim 5 wherein the float has a center of drag, and the tether is attached to the float in front of the center of drag.

10. A water vehicle according to claim 5 wherein the swimmer comprises a fin system which

(a) is secured to the body,

(b) comprises a fin, and

(c) when the vehicle is in wave-bearing water,

(i) has a configuration which changes as a result of the wave motion, and

(ii) interacts with the water to generate forces which tend to move the swimmer in a horizontal direction.

11. A water vehicle according to claim 5 wherein the swimmer comprises at least one member which (i) has a fixed shape and (ii) when the vehicle is in wave-bearing water, generates forces which tend to move the swimmer in a horizontal direction as the swimmer is moved by movement of the float.

12. A water vehicle according to claim 11 wherein the swimmer comprises a single said member having a fixed shape, and all the forces which tend to move the swimmer in a horizontal direction when the vehicle is in wave-bearing water are generated by the single member having a fixed shape.

13. A water vehicle according to claim 5 wherein the steering actuator is a rudder.

14. A water vehicle according to claim 5 wherein the float includes a solar panel.

15. A water vehicle according to claim 5 wherein the swimmer comprises a swimmer body and a fin system which together form a unitary body.

16. A method of utilizing wave power which comprises placing a wave-powered water vehicle in a body of water which has or which is expected to have water waves traveling across its surface, the water vehicle comprising

(1) a float,

(2) a swimmer, and

(3) a tether connecting the float and the swimmer;

the float, swimmer and tether being such that, when the vehicle is in still water,

(i) the float is on or near the surface of the water,

(ii) the swimmer is submerged below the float, and

(iii) the tether is under tension;

the swimmer comprising

(2a) a swimmer body having a longitudinal axis, and

(2b) a fin system which

(a) is secured to the body,

(b) comprises a fin, and

(c) when the vehicle is in wave-bearing water,

(i) has a configuration which changes as a result of the wave motion, and

(ii) interacts with the water to generate forces which tend to move the swimmer in a horizontal direction;

the vehicle having one or more of the following characteristics;

(A) the fin system comprises a fin which rotates about an axis of rotation, the axis of rotation having a spatial relationship to the swimmer body which changes when the vehicle is in wave-bearing water;

(B) the fin system comprises (i) a fin which rotates about an axis of rotation, and (ii) an elastic component which is not part of the fin, and which deforms elastically and thus influences changes in the configuration of the fin system when the vehicle is in wave-bearing water;

(C) the fin system comprises a fin having a leading edge which comprises (i) a relatively rigid central section which has a fixed spatial relationship with the swimmer body, and (ii) relatively deformable outboard sections;

(D) the fin system comprises two generally laminar fins, each of which rotates about an axis of rotation generally aligned with the longitudinal axis of the swimmer body;

(E) the tether comprises an elastically deformable member;

(F) the tether comprises a component which transmits data and/or electrical power;

(G) the swimmer body has a substantially rigid fore section, a midsection which is relatively flexible in the vertical plane, and a substantially rigid aft section;

(H) the swimmer comprises a swimmer body comprising a central tubular housing and wave-actuated fins which extend either side of the housing; and

(I) the swimmer body comprises a generally tubular housing and vertical fin surfaces respectively adjacent to the leading end and the trailing end of the swimmer body.

17. A method according to claim 16 wherein the water vehicle is directed along a desired geographical path.

18. A method according to claim 16 wherein the water vehicle is kept close to a fixed point.

19. A method according to claim 16 wherein all the forces generated by the interaction of the fin system with wave-bearing water are used to move the vehicle in a horizontal direction or are wasted.

20. A method of utilizing wave power which comprises placing a wave-powered water vehicle in a body of water which has or which is expected to have water waves traveling across its surface, the water vehicle comprising

(1) a float,

(2) a swimmer,

(3) a tether connecting the float and the swimmer, and

(4) a computer system;

the float, swimmer and tether being such that, when the vehicle is in still water,

(i) the float is on or near the surface of the water,

(ii) the swimmer is submerged below the float, and

(iii) the tether is under tension;

the swimmer, when the vehicle is in wave-bearing water, interacting with the water to generate forces which tend to move the float horizontally;

the float comprising a satellite-referenced position sensor;

the swimmer comprising (a) a horizontal sensor which senses direction in a horizontal plane, and (b) a steering actuator; and

the computer system (a) being linked to the position sensor, the horizontal sensor and the steering actuator, and (b) containing, or being programmable to contain, instructions to control the steering actuator in response to signals received from the position sensor and the horizontal sensor, or in response to signals received from a sensor on the vehicle.

21. A method according to claim 20 wherein the computer

(a) processes (i) input from the horizontal sensor, (ii) input from the satellite-referenced position sensor, and (iii) geographical coordinates pre-programmed into the computer or input to the computer by radio commands, and

(b) outputs commands to the steering actuator.

22. A method according to claim 20 wherein the computer

(a) processes input from a sensor attached to the vehicle or from a network of vehicles, and

(b) outputs commands to the steering actuator.

23. A method according to claim 20 wherein all the forces generated by the interaction of the fin system with wave-bearing water are used to move the vehicle in a horizontal direction or are wasted.

24. A method of obtaining information which comprises analyzing information obtained from or recorded by a wave-powered water vehicle which comprises

(1) a float,

(2) a swimmer, and

(3) a tether connecting the float and the swimmer;

the float, swimmer and tether being such that, when the vehicle is in still water,

(i) the float is on or near the surface of the water,

(ii) the swimmer is submerged below the float, and

(iii) the tether is under tension;

the swimmer comprising

(2a) a swimmer body having a longitudinal axis, and

(2b) a fin system which

(a) is secured to the body,

(b) comprises a fin, and

(c) when the vehicle is in wave-bearing water,

(i) has a configuration which changes as a result of the wave motion, and

(ii) interacts with the water to generate forces which tend to move the swimmer in a horizontal direction;

the vehicle having one or more of the following characteristics;

(A) the fin system comprises a fin which rotates about an axis of rotation, the axis of rotation having a spatial relationship to the swimmer body which changes when the vehicle is in wave-bearing water;

(B) the fin system comprises (i) a fin which rotates about an axis of rotation, and (ii) an elastic component which is not part of the fin, and which deforms elastically and thus influences changes in the configuration of the fin system when the vehicle is in wave-bearing water;

(C) the fin system comprises a fin having a leading edge which comprises (i) a relatively rigid central section which has a fixed spatial relationship with the swimmer body, and (ii) relatively deformable outboard sections;

(D) the fin system comprises two generally laminar fins, each of which rotates about an axis of rotation generally aligned with the longitudinal axis of the swimmer body;

(E) the tether comprises an elastically deformable member;

(F) the tether comprises a component which transmits data and/or electrical power;

(G) the swimmer body has a substantially rigid fore section, a midsection which is relatively flexible in the vertical plane, and a substantially rigid aft section;

(H) the swimmer comprises a swimmer body comprising a central tubular housing and wave-actuated fins which extend either side of the housing; and

(I) the swimmer body comprises a generally tubular housing and vertical fin surfaces respectively adjacent to the leading end and the trailing end of the swimmer body.

25. A method according to claim 24 wherein the information is derived from signals (i) communicated by communication equipment which is part of the vehicle and (ii) reflecting data collected by a monitoring or sensing device which is part of the vehicle.

26. A method of obtaining information which comprises analyzing information obtained from or recorded by a wave-powered water vehicle which comprises

(1) a float,

(2) a swimmer,

(3) a tether connecting the float and the swimmer, and

(4) a computer system;

the float, swimmer and tether being such that, when the vehicle is in still water,

(i) the float is on or near the surface of the water,

(ii) the swimmer is submerged below the float, and

(iii) the tether is under tension;

the swimmer, when the vehicle is in wave-bearing water, interacting with the water to generate forces which tend to move the float horizontally;

the float comprising a satellite-referenced position sensor;

the swimmer comprising (a) a horizontal sensor which senses direction in a horizontal plane, and (b) a steering actuator; and

the computer system (a) being linked to the position sensor, the horizontal sensor and the steering actuator, and (b) containing, or being programmable to contain, instructions to control the steering actuator in response to signals received from the position sensor and the horizontal sensor, or in response to signals received from a sensor on the vehicle.

27. A method according to claim 26 wherein the information is derived from signals (i) communicated by communication equipment which is part of the vehicle and (ii) reflecting data collected by a monitoring or sensing device which is part of the vehicle.

28. A method for controlling a function of a wave-powered water vehicle, the method comprising sending signals to a wave-powered water vehicle which comprises

(1) a float,

(2) a swimmer, and

(3) a tether connecting the float and the swimmer,

the float, swimmer and tether being such that, when the vehicle is in still water,

(i) the float is on or near the surface of the water,

(ii) the swimmer is submerged below the float, and

(iii) the tether is under tension;

the swimmer comprising

(2a) a swimmer body having a longitudinal axis, and

(2b) a fin system which

(a) is secured to the body,

(b) comprises a fin, and

(c) when the vehicle is in wave-bearing water,

(i) has a configuration which changes as a result of the wave motion, and

(ii) interacts with the water to generate forces which tend to move the swimmer in a horizontal direction;

the vehicle having one or more of the following characteristics;

(A) the fin system comprises a fin which rotates about an axis of rotation, the axis of rotation having a spatial relationship to the swimmer body which changes when the vehicle is in wave-bearing water;

(B) the fin system comprises (i) a fin which rotates about an axis of rotation, and (ii) an elastic component which is not part of the fin, and which deforms elastically and thus influences changes in the configuration of the fin system when the vehicle is in wave-bearing water;

(C) the fin system comprises a fin having a leading edge which comprises (i) a relatively rigid central section which has a fixed spatial relationship with the swimmer body, and (ii) relatively deformable outboard sections;

(D) the fin system comprises two generally laminar fins, each of which rotates about an axis of rotation generally aligned with the longitudinal axis of the swimmer body;

(E) the tether comprises an elastically deformable member;

(F) the tether comprises a component which transmits data and/or electrical power;

(G) the swimmer body has a substantially rigid fore section, a midsection which is relatively flexible in the vertical plane, and a substantially rigid aft section;

(H) the swimmer comprises a swimmer body comprising a central tubular housing and wave-actuated fins which extend either side of the housing; and

(I) the swimmer body comprises a generally tubular housing and vertical fin surfaces respectively adjacent to the leading end and the trailing end of the swimmer body.

29. A method according to claim 28 wherein the signals direct the water vehicle along a desired geographical path.

30. A method according to claim 28 wherein the signals direct the water vehicle to stay close to a fixed point.

31. A method for controlling a function of a wave-powered water vehicle, the method comprising sending signals to a wave-powered water vehicle which comprises

(1) a float,

(2) a swimmer,

(3) a tether connecting the float and the swimmer, and

(4) a computer system;

the float, swimmer and tether being such that, when the vehicle is in still water,

(i) the float is on or near the surface of the water,

(ii) the swimmer is submerged below the float, and

(iii) the tether is under tension;

the swimmer, when the vehicle is in wave-bearing water, interacting with the water to generate forces which tend to move the float horizontally;

the float comprising a satellite-referenced position sensor;

the swimmer comprising (a) a horizontal sensor which senses direction in a horizontal plane, and (b) a steering actuator; and

the computer system (a) being linked to the position sensor, the horizontal sensor and the steering actuator, (b) containing, or being programmable to contain, instructions to control the steering actuator in response to signals received from the position sensor and the horizontal sensor, or in response to signals received from a sensor on the vehicle.

32. A method according to claim 31 wherein the water vehicle includes communication equipment for receiving signals from a base station, the signals are signals from the base station, and the computer processes input which comprises the signals.

33. A wave-powered water vehicle which comprises

(1) a float,

(2) a swimmer, and

(3) a tether connecting the float and the swimmer;

the float, swimmer and tether being such that, when the vehicle is in still water,

(i) the float is on or near the surface of the water,

(ii) the swimmer is submerged below the float, and

(iii) the tether is under tension;

the swimmer comprising

(2a) a swimmer body having a longitudinal axis, and

(2b) a fin system which

(a) is secured to the body,

(b) when the vehicle is in wave-bearing water,

(i) has a configuration which changes as a result of the wave motion, and

(ii) interacts with the water to generate forces which tend to move the swimmer in a horizontal direction; and

(c) comprises

(i) a fin which rotates about an axis of rotation which is generally transverse to the longitudinal axis of the swimmer body, and

(ii) an elastic component which is not part of the fin, and which deforms elastically and thus influences changes in the configuration of the fin system when the vehicle is in wave-bearing water.

34. A water vehicle according to claim 33 wherein the fin is a generally laminar fin and the elastic component is a coil spring.

35. A water vehicle according to claim 34 wherein the generally laminar fin is elastically deformable.

36. A water vehicle according to claim 33 wherein the elastic component is a torsion bar.

37. A water vehicle according to claim 33 wherein the fin is generally laminar and elastically deformable.

38. A water vehicle according to claim 33 wherein the fin system comprises a plurality of generally laminar and elastically deformable fins.

39. A water vehicle according to claim 38 wherein said fins lie in the same generally horizontal plane.

40. A water vehicle according to claim 39 wherein the fin system includes a rigid spine which is rigidly fixed above the body portion and to which the fins are secured.

41. A wave-powered water vehicle which comprises

(1) a float,

(2) a swimmer, and

(3) a tether which connects the float and the swimmer and which comprises a coil spring;

the float, swimmer and tether being such that, when the vehicle is in still water,

(i) the float is on or near the surface of the water,

(ii) the swimmer is submerged below the float, and

(iii) the tether is under tension;

the swimmer comprising

(2a) a swimmer body having a longitudinal axis, and

(2b) a fin system which

(a) is secured to the body,

(b) comprises a fin, and

(c) when the vehicle is in wave-bearing water,

(i) has a configuration which changes as a result of the wave motion, and

(ii) interacts with the water to generate forces which tend to move the swimmer in a horizontal direction.

42. A wave-powered water vehicle which comprises

(1) a float,

(2) a swimmer, and

(3) a tether which (i) connects the float and the swimmer, and (ii) comprises at least one component which transmits one or both of data and electrical power;

the float, swimmer and tether being such that, when the vehicle is in still water,

(1) the float is on or near the surface of the water,

(ii) the swimmer is submerged below the float, and

(iii) the tether is under tension; and

the swimmer comprising

(2a) a swimmer body having a longitudinal axis, and

(2b) a fin system which

(a) is secured to the body,

(b) comprises a fin, and

(c) when the vehicle is in wave-bearing water,

(i) has a configuration which changes as a result of the wave motion, and

(ii) interacts with the water to generate forces which tend to move the swimmer in a horizontal direction.

43. A water vehicle according to claim 42 wherein

(1) the tether comprises a tensile member which carries tensile load between the float and the swimmer, and

(2) the at least one component which transmits one or both of data and electrical power does not carry any tensile load.

44. A water vehicle according to claim 43 wherein the tether has a streamlined shape, and the tensile member is at the front of the streamlined shape.

45. A water vehicle according to claim 43 wherein the tether has an aligned dimension of 0.5 to 1.0 inch and a transverse dimension of about 0.19 inch.

46. A wave-powered water vehicle which comprises

(1) a float,

(2) a swimmer, and

(3) a tether connecting the float and the swimmer;

the float, swimmer and tether being such that, when the vehicle is in still water,

(i) the float is on or near the surface of the water,

(ii) the swimmer is submerged below the float, and

(iii) the tether is under tension;

the swimmer comprising

(2a) a swimmer body which has a longitudinal axis and which comprises one or more components selected from communications equipment, recording equipment and sensors, and

(2b) a fin system which

(a) is secured to the body,

(b) comprises a fin, and

(c) when the vehicle is in wave-bearing water,

(i) has a configuration which changes as a result of the wave motion, and

(ii) interacts with the water to generate forces which tend to move the swimmer in a horizontal direction.

47. A water vehicle according to claim 46 wherein the float includes a satellite-referenced position sensor and a solar panel.