Marine Vessel Thrust Vector Alignment for Station Keeping
Solution Overview
Problem
Existing marine vessel positioning systems face inefficiencies in station keeping modes due to variations in available thrust, particularly when maneuvering sideways, as propulsion devices are less efficient in reverse directions and transverse to the vessel's heading.
Innovation Solution
A system comprising multiple marine propulsion devices controlled by a programmable circuit that calculates and aligns the thrust vector with the vessel's heading, switching between modes to maintain position and adjust heading, automatically activating a thrust maximization mode when the second mode fails to maintain the global position.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If propulsion devices are vectored to achieve side directed forces for station keeping, then the vessel can maintain position, but the available thrust in the actual direction of vessel movement is reduced
Solution Approach 1:
The system dynamically adjusts the orientation of propulsion devices between two modes: a first mode where propulsion devices are vectored to generate side-directed forces for station keeping, and a second mode where propulsion devices are aligned with the vessel's actual heading to maximize available thrust. The control device switches between these modes based on real-time vessel position and thrust requirements, allowing the system to optimize between station keeping capability and available thrust depending on the operational context
Solution Approach 2:
The control device changes the operational parameters of the propulsion devices by adjusting their orientation angles relative to the vessel's heading. In the first mode, propulsion devices are oriented at angles that generate lateral thrust components for position maintenance. In the second mode, the orientation parameter is changed to align propulsion devices with the vessel's actual heading, thereby maximizing the thrust component in the direction of movement. This parameter adjustment allows the system to resolve the contradiction between station keeping and available thrust
2Reliability
If propulsion devices operate in reverse direction to maintain position, then the vessel can counteract external forces, but propulsion efficiency is reduced
Solution Approach 1:
The system dynamically selects between operational modes based on the vessel's current state and external force conditions. When the vessel requires counteracting external forces, the control device determines whether to use reverse propulsion or alternative thrust vectoring strategies. By switching between modes, the system can maintain position while minimizing the use of inefficient reverse propulsion operations
Solution Approach 2:
The control device continuously monitors the vessel's position, heading, and the forces acting upon it through feedback from sensors. This feedback information is used to calculate the required thrust vector and determine the optimal operational mode. The system adjusts propulsion device operation in real-time based on feedback, selecting reverse propulsion only when necessary and preferring efficient forward propulsion when conditions allow, thereby optimizing overall energy usage while maintaining position
Data Source
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AI summary
Systems and methods for orienting a marine vessel enhance available thrust in a station keeping mode. A control device having a memory and a programmable circuit is programmed to control operation of a plurality of marine propulsion devices to maintain orientation of a marine vessel in a selected global position. The control device is programmed to calculate a direction of a resultant thrust vector associated with the plurality of marine propulsion devices that is necessary to maintain the vessel in the selected global position. The control device is programmed to control operation of the plurality of marine propulsion devices to change the actual heading of the marine vessel to align the actual heading with the thrust vector.