SYSTEMS AND METHODS FOR SEA STATE PREDICTION AND AUTOMATED VESSEL NAVIGATION

• US 20120130569A1
• Filed: 06/15/2011
• Published: 05/24/2012
• Est. Priority Date: 06/15/2010
• Status: Active Grant

• Current Assignee: California Institute of Technology
• Original Assignee: California Institute of Technology
• Inventors: Huntsberger, Terrance L., Aghazarian, Hrand, Rankin, Arturo, Howard, Andrew B., Reinhart, Rene Felix
• Granted Patent: US 8,989,948 B2
• Time in Patent Office: Days
• US Class Current: 701/21
• CPC Class Codes: B63B 79/20 using models or simulation, e.g. statistical models or stochastic models
• CPC Class Codes: B63H 25/04 automatic, e.g. reacting to compass
• CPC Class Codes: G01C 11/00 Photogrammetry or videogrammetry, e.g. stereogrammetry; Photographic surveying
• CPC Class Codes: G01C 11/04 Interpretation of pictures
• CPC Class Codes: G01C 13/002 Measuring the movement of open water
• CPC Class Codes: G01C 21/203 Specially adapted for sailing ships
• CPC Class Codes: G05D 1/0206 specially adapted to water vehicles
• CPC Class Codes: G05D 1/0251 extracting 3D information from a plurality of images taken from different locations, e.g. stereo vision stereoscopic image analysis H04N13/00; depth recovery from images G06T7/593
• CPC Class Codes: G08G 3/00 Traffic control systems for marine craft marking of navigational route B63B22/16, B63B51/00

Abstract

Systems and methods for sea state prediction and autonomous navigation in accordance with embodiments of the invention are disclosed. One embodiment of the invention includes a method of predicting a future sea state including generating a sequence of at least two 3D images of a sea surface using at least two image sensors, detecting peaks and troughs in the 3D images using a processor, identifying at least one wavefront in each 3D image based upon the detected peaks and troughs using the processor, characterizing at least one propagating wave based upon the propagation of wavefronts detected in the sequence of 3D images using the processor, and predicting a future sea state using at least one propagating wave characterizing the propagation of wavefronts in the sequence of 3D images using the processor. Another embodiment includes a method of autonomous vessel navigation based upon a predicted sea state and target location.

Claims

1. A method of predicting a future sea state comprising:

generating a sequence of at least two 3D images of a sea surface using at least two image sensors;

detecting peaks and troughs in the 3D images using a processor;

identifying at least one wavefront in each 3D image based upon the detected peaks and troughs using the processor;

characterizing at least one propagating wave based upon the propagation of wavefronts detected in the sequence of 3D images using the processor; and

predicting a future sea state using the at least one propagating wave characterizing the propagation of wavefronts in the sequence of 3D images using the processor.

2. The method of claim 1, wherein generating a sequence of at least two 3D images of a sea surface uses two pairs of image sensors.

3. The method of claim 1, wherein generating a sequence of at least two 3D images of a sea surface also includes using a radar sensor in combination with the at least two image sensors.

4. The method of claim 1, wherein the images sensors capture black and white images.

5. The method of claim 1, wherein the image sensors capture color images.

6. The method of claim 1, wherein detecting peaks and troughs comprises using a random sampling process.

7. The method of claim 1, wherein detecting peaks and troughs comprises using a least means squares process.

8. The method of claim 1, wherein detecting peaks and troughs comprises using a thresholding process.

9. The method of claim 1, wherein identifying at least one wavefront comprises using a nearest neighbor process.

10. The method of claim 1, wherein characterizing at least one propagating wave comprises determining the amplitude, frequency and velocity of the at least one propagating wave.

11. The method of claim 1, wherein characterizing at least one propagating wave comprises determining the direction of the at least one propagating wave.

12. The method of claim 1, wherein characterizing at least one propagating wave comprises determining the wave phase of the at least one propagating wave.

13. The method of claim 1, further comprising autonomously navigating a vessel based upon the predicted future sea state.

14. A method of autonomous vessel navigation based upon a predicted sea state and target location, comprising:

determining at least one subtarget based upon the target location and the predicted sea state using a macronavigation system;

communicating the at least one subtarget to the micronavigation system; and

controlling a vessel to navigate toward the at least one subtarget using a micronavigation system.

15. The method of claim 14, wherein the predicted sea state comprises a main wave direction.

16. The method of claim 14, wherein the predicted sea state comprises a wave phase information.

17. The method of claim 14, wherein the subtarget is the target location.

18. The method of claim 14, wherein the micronavigation system comprises a proportional integral derivative controller.

19. The method of claim 14, wherein navigating toward the at least one subtarget causes the vessel to tack relative to a main wave direction.

20. The method of claim 14, wherein the subtarget causes the vessel to navigate at 60 degrees relative to the main wave direction.

21. The method of claim 14, wherein controlling the vessel comprises controlling the throttle and the rudder of the vessel.

22. The method of claim 14, wherein the predicted sea state is predicted using at least one propagating wave characterizing propagation of wavefronts from detected peaks and troughs in a sequence of 3D images.

23. A system for predicting a future sea state comprising:

a sensor system configured to capture information concerning the shape of the sea surface;

a sea state processor configured to communicate with the sensor system;

wherein the sensor system and the sea state processor are configured so that the captured information is used to generate a sequence of 3D images of a sea surface;

wherein the sea state processor is configured to;

detect peaks and troughs in the 3D images;

identify at least one wavefront in each 3D image based upon the detected peaks and troughs;

characterize at least one propagating wave based upon the propagation of wavefronts detected in the sequence of 3D images using the processor; and

predict a future sea state using the at least one propagating wave characterizing the propagation of wavefronts in the sequence of 3D images using the processor.

24. The system of claim 23, wherein the sensor system comprises two pairs of image sensors.

25. The system of claim 23, wherein the sensor system comprises a radar sensor.

26. The system of claim 23, wherein the sensor system and the sea state processor are configured so that the captured information is used to generate a sequence of black and white 3D images of a sea surface.

27. The system of claim 23, wherein the sensor system and the sea state processor are configured so that the captured information is used to generate a sequence of color 3D images of a sea surface.

28. The system of claim 23, wherein the sea state processor is configured to detect peaks and troughs using a random sampling process.

29. The system of claim 23, wherein the sea state processor is configured to detect peaks and troughs using a least means squares process.

30. The system of claim 23, wherein the sea state processor is configured to detect peaks and troughs using a thresholding process.

31. The system of claim 23, wherein the sea state processor is configured to identify the at least one wavefront using a nearest neighbor process.

32. The system of claim 23, wherein the sea state processor is configured to characterize the at least one propagating wave by the amplitude, frequency and velocity of the at least one propagating wave.

33. The system of claim 23, wherein the sea state processor is configured to characterize the at least one propagating wave by the direction of the at least one propagating wave.

34. The system of claim 23, wherein the sea state processor is configured to characterize the at least one propagating wave by the wave phase of the at least one propagating wave.

35. The system of claim 23, further comprising an autonomous vessel navigation system that utilizes the predicted future sea state to determine vessel heading when navigating toward a target.

36. An autonomous vessel navigation system, comprising:

a macronavigation system configured to receive a predicted sea state and a target as inputs and to generate a subtarget as an output; and

a micronavigation system configured to receive a subtarget as an input and to generate vessel control signals as outputs;

wherein the macronavigation system is configured to;

determine at least one subtarget based upon the target location and the predicted sea state; and

communicate the at least one subtarget to the micronavigation system; and

wherein the micronavigation system is configured to generate vessel control signals that head a vessel toward the at least one subtarget.

37. The system of claim 36, wherein the predicted sea state comprises a main wave direction.

38. The system of claim 36, wherein the predicted sea state comprises wave phase information.

39. The system of claim 36, wherein the subtarget is the target location.

40. The system of claim 36, wherein the micronavigation system comprises a proportional integral derivative controller.

41. The system of claim 36, wherein the macronavigation system is configured to cause the vessel to tack relative to a main wave direction.

42. The system of claim 36, wherein the macronavigation system is configured to determine at least one subtarget that causes vessel navigation at 60 degrees relative to the main wave direction.

43. The system of claim 36, wherein the micronavigation system is configured to generate vessel control signals configured to control the throttle and the rudder of a vessel.

44. The system of claim 36, wherein the macronavigation system is configured to receive the predicted sea state from a system for predicting a future sea state.