Method and system for maneuvering movable object

• US 20040006423A1
• Filed: 05/20/2003
• Published: 01/08/2004
• Est. Priority Date: 05/20/2002
• Status: Active Grant

• Current Assignee: Kawasaki Jukogyo Kabushiki Kaisha (Kawasaki Heavy Industries Limited)
• Original Assignee: Kabushiki Kaisha Kawasaki Zosen, Kawasaki Jukogyo Kabushiki Kaisha (Kawasaki Heavy Industries Limited)
• Inventors: Fujimoto, Hiroaki, Higashi, Masaaki, Saito, Yasuo, Nakashima, Kenichi, Hamamatsu, Masanori, Ohnishi, Hiroshi, Kohno, Yukinobu
• Granted Patent: US 7,366,593 B2
• Time in Patent Office: Days
• US Class Current: 701/201
• CPC Class Codes: G05D 1/0206 specially adapted to water vehicles

Abstract

A movable object maneuver method wherein a destination point is set; wherein a thrust value is calculated in real time which minimizes or maximizes a performance index associated with one or more state variables and thrust required for a movable object to reach the destination point and which takes into account non-linear conditions inherent to the movable object; and wherein the movable object is moved based on the calculated thrust value.

Claims

1. A method of maneuvering a movable object, comprising:

setting a destination point;

calculating a thrust value in real time which minimizes or maximizes a performance index associated with one or more state variables and thrust required for a movable object to reach the destination point and which takes into account non-linear conditions inherent to the movable object, and

moving the movable object based on the calculated thrust value.

2. The method according to claim 1, wherein the thrust value is calculated in real time which minimizes or maximizes the performance index over a specified period of time from the present time to a future time.

17. The method according to claim 1, wherein upon detection of an event, the destination point is set by switching between the present location and any of other points than the present location.

18. The method according to any one of claims 1, wherein the performance index includes the state variables and the thrust as variables and wherein the state of the movable object is estimated, using a non-linear or linear state observer.

19. The method according to any one of claims 1, wherein necessary items including the destination point and the performance index are set using a human-machine interface.

3. A method of maneuvering a movable object, comprising:

setting a destination point;

calculating a thrust value in real time which minimizes or maximizes a performance index associated with thrust required for a movable object to reach the destination point;

moving the movable object based on the calculated thrust value;

setting one or more transit points on a planned route for the movable object;

and sequentially setting one or more set transit points as the destination point.

4. The method according to claim 3, wherein the thrust value is calculated in real time which minimizes or maximizes the performance index over a specified period of time from the present time to a future time.

5. The method according to any one of claim 3, wherein the performance index includes weights for the state variables, the thrust and each term, wherein the weights arc set as constraints which limit the values of the state variables and the thrust, and wherein the thrust value restricted by the set constraints is calculated.

6. The method according to claim 3, wherein the planned route includes only two transit points which are a starting point and a terminal point, and the two transit points are set to the same point.

7. The method according to claim 3, wherein a guide point is set which consists of a virtual point and moves on the planned route, preceding the movable object, and wherein when the guide point has reached a transit point which is the present destination point, the destination point is switched to the next transit point.

8. The method according to claim 3, wherein the performance index includes weights for the state variables, the thrust and each term, wherein the weights are set for each zone of the planned route as constraints which limit the values of the state variables and the thrust, each zone being defined by the transit points and wherein the thrust value restricted by the constraints corresponding to each transit point is calculated.

9. The method according to claim 5, wherein the weights are set as constants.

10. The method according to claim 5, wherein the weights are set as function of positions.

11. The method according to claim 5, wherein the weights are set as functions of the position and attitude of the movable object.

12. The method according to claim 5, wherein the weights are set as functions of deviation from the state variables at the destination point.

13. The method according to claim 5, wherein the weights are set as function of speeds.

14. The method according to claim 5, wherein the weights are set as function of times.

15. The method according to claim 5, wherein the weights are set as functions of an event signal.

16. The method according to claim 5, wherein the weights are set as functions of data on obstacles.

39. The method according to any one of claims 3, wherein the movable object is a ship.

40. The method according to any one of claims 3, wherein the movable object is an underwater craft.

41. The method according to any one of claims 3, wherein the movable object is an aircraft.

20. A system for maneuvering a movable object, comprising:

means for setting a destination point;

arithmetic operation means for calculating a thrust value in real time which minimizes or maximizes a performance index associated with one or more state variables and thrust required for a movable object to reach the destination point and which takes into account non-linear conditions inherent to the movable object; and

actuators for moving the movable object based on the calculated thrust value.

21. The system according to claim 20, wherein the arithmetic operation means calculates the thrust value in real time which minimizes or maximizes the performance index over a specified period of time from the present time to a future time.

22. A system for maneuvering a movable object, comprising:

means for setting a destination point;

arithmetic operation means for calculating a thrust value in real time which minimizes or maximizes a performance index associated with thrust required for a movable object to reach the destination point; and

actuators for moving the movable object based on the calculated thrust value,

the system further comprising means for setting a planned route for the movable object and one or more transit points on the planned route,

wherein one or more set transit points are sequentially set as the destination point.

23. The system according to claim 22, wherein the arithmetic operation means calculates the thrust value in real time which minimizes or maximizes the performance index over a specified period of time from the present time to a future time,

24. The system according to any one of claims 22,

wherein the performance index includes weights for the state variables, the thrust and each term,

which further comprises means for setting the weights as constraints which limit the values of the state variables and the thrust, and

wherein the arithmetic operation means calculates the thrust value restricted by the set constraints.

25. The system according to claim 22, wherein the planned route includes only two transit points which are a starting point and a terminal point, and the two transit points are set to the same point.

26. The system according to claim 22, further comprising means for setting a guide point which consists of a virtual point and moves on the planned route, preceding the movable object,

wherein when the guide point has reached a transit point which is the present destination point, the destination point is switched to the next transit point.

27. The system according to claim 22,

wherein the performance index includes weights for the state variables, the thrust and each term,

which further comprises means for setting the weights for each zone of the planned route as constraints which limit the values of the state variables and the thrust, each zone being defined by the transit points and

wherein the arithmetic operation means calculates the thrust value restricted by the constraints corresponding to each transit point.

28. The system according to claim 22, wherein the weights are set as constants.

29. The system according to claim 24, wherein the weights are set as function of positions.

30. The system according to claim 24, wherein the weights are set as functions of the position and attitude of the movable object.

31. The system according to claim 24, wherein the weights are set as functions of deviation from the state variables at the destination point.

32. The system according to claim 24, wherein the weights are set as function of speeds.

33. The system according to claim 24, wherein the weights are set as function of times.

34. The system according to claim 24, wherein the weights are set as functions of an event signal.

35. The system according to claim 24, wherein the weights are set as functions of data on obstacles.

36. The system according to claim 24 further comprising means for detecting an event,

wherein upon detection of an event, the destination point is set by switching between the present location and any of other points than the present location.

37. The system according to any one of claims 22,

wherein the performance index includes the state variables and the thrust as variables, and

which further comprises a non-linear or linear state observer for estimating the state of the movable object.

38. The system according to any one of claims 22, further comprising a human-machine interface for setting necessary items including the destination point and the performance index.

42. The system according to any one of claims 22, wherein the movable object is a ship.

43. The system according to any one of claims 22, wherein the movable object is an underwater craft.

44. The system according to any one of claims 22, wherein the movable object is an aircraft.