Control of a Waterjet Propelled Vessel
First Claim
1. A method for controlling the heading of a watercraft, comprising:
- acquiring a desired heading of the watercraft;
acquiring an actual heading of the watercraft at time T0;
calculating a heading error by comparing the desired heading with the actual heading;
determining a rate of change of the heading error;
determining algorithm gains used to control at least one of the amount and rate of a deflection of a nozzle of the watercraft for use in maintaining the heading of the watercraft;
determining a value for a nozzle control signal by taking into account each determined algorithm gain;
determining an amount of deflection for a nozzle of the watercraft, for altering a heading of the watercraft, based on the value for the nozzle control signal;
deflecting the nozzle based on the determined amount of deflection;
repeating the above steps until the actual heading equals the desired heading.
2 Assignments
0 Petitions
Accused Products
Abstract
A method for controlling a watercraft includes acquiring a desired heading of the watercraft, acquiring an actual heading of the watercraft at time T0, calculating a heading error by comparing the desired heading with the actual heading and determining a rate of change of the heading error. A P gain, I gain and D gain for use in maintaining the heading of the watercraft is determined and used to calculate factors related to heading error, cumulative heading error and rate of change of heading error. These factors are summed to form a control value for deflecting a nozzle of the watercraft to maintain a heading of the watercraft. Further embodiments include methods for calculating and correcting a heading of the watercraft, as well as methods for controlling roll out and sideways motion of the watercraft.
-
Citations
59 Claims
-
1. A method for controlling the heading of a watercraft, comprising:
-
acquiring a desired heading of the watercraft; acquiring an actual heading of the watercraft at time T0; calculating a heading error by comparing the desired heading with the actual heading; determining a rate of change of the heading error; determining algorithm gains used to control at least one of the amount and rate of a deflection of a nozzle of the watercraft for use in maintaining the heading of the watercraft; determining a value for a nozzle control signal by taking into account each determined algorithm gain; determining an amount of deflection for a nozzle of the watercraft, for altering a heading of the watercraft, based on the value for the nozzle control signal; deflecting the nozzle based on the determined amount of deflection; repeating the above steps until the actual heading equals the desired heading. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 57)
-
-
14. A method for calculating a heading of a watercraft, comprising:
-
acquiring a heading of the watercraft at a base time; acquiring a heading turn rate from an angular rate of turn sensor of the watercraft at a later time; determining whether the acquired heading is believed accurate at the later time; if the acquired heading is believed inaccurate, calculating a heading of the watercraft based on the heading turn rate and the originally acquired heading; outputting the calculated heading for control of the heading of the watercraft. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28)
-
-
29. A method for correcting a heading of a watercraft, comprising:
-
measuring an amount of error induced by the effect of at least one disturbance on at least one of x, y and z heading data from a heading sensor; acquiring at least one of x, y and z heading data from a heading sensor; determining whether the at least one disturbance is occurring; correcting the heading data in the occurrence of a disturbance by adding a correction value to the heading that offsets the measured amount of error induced by the disturbance; outputting the corrected heading data for control of the heading of the watercraft. - View Dependent Claims (30, 31, 32, 33)
-
-
34. A method for controlling roll out of a watercraft, comprising:
-
determining whether a nozzle control apparatus is off center to alter a position of a nozzle of the watercraft; if the nozzle control apparatus is off center, setting a nozzle control command to a nozzle control apparatus command; determining whether the nozzle control apparatus has been returned to a center position; if the nozzle control apparatus has been returned to a center position, setting a nozzle control command to oppose a turn of the watercraft. - View Dependent Claims (35, 36, 37, 38, 39, 40, 41, 42, 43)
-
-
44. A method for controlling a watercraft having a rear propulsion device and a thruster, comprising:
during at least one of initiation and cessation of sideways movement of the watercraft by engagement/disengagement of the thruster, prepositioning an angle of the rear propulsion device to provide a sideways force that minimizes vessel yaw prior to the occurrence of a heading error, the prepositioned angle based on the operating characteristics of the watercraft. - View Dependent Claims (45, 46, 47, 58)
-
48. A method for controlling a watercraft having a rear propulsion device and a thruster, comprising:
-
initiating a sideways movement of the watercraft by engaging the rear propulsion device while delaying engagement of the thruster; engaging the thruster after a first predetermined time delay to assist in the sideways movement of the watercraft after a stern of the watercraft has gained sideways momentum from the rear propulsion device, the first predetermined time delay based on the operating characteristics of the watercraft to minimize yaw of the watercraft during the sideways movement. - View Dependent Claims (49, 50, 51, 59)
-
-
52. A method for compensating for disturbances of a magnetic heading sensor of a watercraft, comprising:
reducing the effect of electro-magnetic field interference from electrical equipment of the watercraft on the accuracy of a heading signal from the magnetic sensor by changing a use of the heading signal based on at least one of a function mode of the watercraft and a position of a vessel movement control apparatus by at least one of;
compensating for the field interference and acquiring the heading signal only when electro-magnetic interference is sufficiently low to prevent substantive inaccuracy of the heading data.- View Dependent Claims (53, 54, 55, 56)
Specification