Station keeping and waypoint tracking methods
A method for controlling movement of a marine vessel includes controlling a propulsion device to automatically maneuver the vessel along a track including a series of waypoints, and determining whether the next waypoint is a stopover waypoint at or near which the vessel is to electronically anchor. If the next waypoint is the stopover waypoint, a control module calculates a distance between the vessel and the stopover waypoint. In response to the calculated distance being less than or equal to a threshold distance, the propulsion device's thrust is decreased. In response to sensing that the vessel thereafter slows to a first threshold speed, the vessel's speed is further reduced. In response to sensing that the vessel thereafter slows to a second, lower threshold speed or passes the stopover waypoint, the propulsion device is controlled to maintain the vessel at an anchor point that is at or near the stopover waypoint.
1. A method for controlling movement of a marine vessel powered by a marine propulsion system commanded by a control module, the method being carried out by the control module and comprising:
controlling a propulsion device of the marine propulsion system so as to automatically maneuver the marine vessel along a track including a series of waypoints;
determining whether a next waypoint in the series of waypoints is a predetermined stopover waypoint at or near which the marine vessel is to electronically anchor;
in response to determining that the next waypoint is the predetermined stopover waypoint, calculating a distance between the marine vessel and the predetermined stopover waypoint;
in response to the calculated distance being less than or equal to a threshold distance, decreasing a magnitude of thrust of the propulsion device;
in response to sensing that the marine vessel has thereafter slowed to a first threshold speed, controlling the marine propulsion system to further decrease vessel speed; and
in response to sensing that one of (a) the marine vessel has thereafter slowed to a second threshold speed that is less than the first threshold speed or (b) the calculated distance has thereafter begun to increase, controlling the propulsion device so as to maintain the marine vessel at an anchor point that is at or near the predetermined stopover waypoint.
2. The method of claim 1 , further comprising automatically controlling at least one of the magnitude of thrust, a shift position, and a steering angle of the propulsion device so as to maintain the marine vessel at a given heading.
3. The method of claim 2 , further comprising setting a current, actual geographic location of the marine vessel as the anchor point in response to reaching the second threshold speed or in response to the calculated distance increasing.
4. The method of claim 3 , further comprising setting a current, actual heading of the marine vessel as the given heading in response to reaching the second threshold speed or in response to the calculated distance increasing.
5. The method of claim 2 , further comprising setting a geographic location of the predetermined stopover waypoint as the anchor point.
6. The method of claim 5 , further comprising setting an operator-selected heading as the given heading.
7. The method of claim 1 , further comprising decreasing the propulsion device's magnitude of thrust upon reaching the threshold distance from the predetermined stopover waypoint by slowing a speed of an engine of the propulsion device at a given rate.
8. The method of claim 7 , wherein the given rate at which the engine speed is slowed is inversely proportional to a current, actual speed of the marine vessel upon reaching the threshold distance from the predetermined stopover waypoint.
9. The method of claim 7 , further comprising slowing the engine speed at the given rate until the engine speed reaches a predefined idle speed.
10. The method of claim 2 , further comprising disregarding a position of a throttle lever of the marine propulsion system until an operator of the marine vessel moves the throttle lever to a neutral position and subsequently commands the marine vessel to move off the anchor point or to rotate away from the given heading.
11. The method of claim 1 , further comprising generating a prompt while the marine vessel is being maintained at the anchor point, wherein the prompt alerts an operator of the marine vessel to move a throttle lever of the marine propulsion system to a neutral position.
12. The method of claim 1 , further comprising shifting the propulsion device into reverse in response to sensing that the marine vessel has slowed to the first threshold speed.
13. A system for controlling movement of a marine vessel, the system comprising:
a marine propulsion system including a marine propulsion device;
a control module that controls a magnitude of thrust, a shift position, and a steering angle of the marine propulsion device;
an electronic navigation device that provides to the control module a desired track including a series of waypoints, wherein the series of waypoints includes a stopover waypoint at or near which the marine vessel is to electronically anchor; and
a position determination device that provides to the control module a current, actual geographic location of the marine vessel as the marine vessel navigates the desired track under the command of the control module;
wherein, in response to determining that the marine vessel has reached a threshold distance from the stopover waypoint, the control module commands the marine propulsion device's magnitude of thrust to decrease;
wherein, in response to sensing that the marine vessel has thereafter slowed to a first threshold speed, the control module commands the marine propulsion system to further decrease vessel speed; and
wherein, in response to sensing that one of (a) the marine vessel has thereafter slowed to a second threshold speed that is less than the first threshold speed or (b) a distance between the marine vessel and the stopover waypoint has thereafter begun to increase, the control module controls at least one of the magnitude of thrust, the shift position, and the steering angle of the marine propulsion device so as to maintain the marine vessel at an anchor point that is at or near the stopover waypoint.
14. The system of claim 13 , further comprising a heading detector that detects a heading of the marine vessel, wherein the control module controls at least one of the magnitude of thrust, the shift position, and the steering angle of the marine propulsion device so as to maintain the marine vessel at a heading that is equal to a given heading.
15. The system of claim 14 , wherein, in response to the marine vessel reaching the second threshold speed or in response to the distance between the marine vessel and the stopover waypoint increasing, the control module sets the given heading as one of a current, actual heading of the marine vessel or an operator-selected heading.
16. The system of claim 15 , wherein the control module sets a geographic location of the stopover waypoint as the anchor point.
17. The system of claim 15 , wherein, in response to the marine vessel reaching the second threshold speed or in response to the distance between the marine vessel and the stopover waypoint increasing, the control module sets the current, actual geographic location of the marine vessel as the anchor point.
18. The system of claim 14 , wherein the marine propulsion system further includes a throttle lever, and wherein the control module disregards a position of the throttle lever until an operator of the marine vessel moves the throttle lever to a neutral position and subsequently commands the marine vessel to move off the anchor point or to rotate away from the given heading.
19. The system of claim 13 , wherein the marine propulsion system further includes a throttle lever and a notification device, and wherein the control module commands the notification device to emit a prompt that alerts an operator of the marine vessel to move the throttle lever to a neutral position while the marine vessel is being maintained at the anchor point.
20. The system of claim 13 , wherein the electronic navigation device is a chart plotter including an operator interface that allows an operator of the marine vessel to select one or more of the desired track, the stopover waypoint, the threshold distance, the first threshold speed, and the second threshold speed.
21. The system of claim 13 , wherein the control module defaults to setting a final waypoint in the desired track as the stopover waypoint.
22. The system of claim 13 , wherein, in response to sensing that the marine vessel has slowed to the first threshold speed, the control module commands the marine propulsion device to shift into reverse.