Marine Propulsion Wave Control for Head and Following Seas
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing marine propulsion systems fail to adequately control vessel stability and ride comfort during waves, as they do not differentiate between head waves and following waves, leading to insufficient hull stability and comfort.
Innovation Solution
A marine propulsion system with an up-and-down movement sensor and controller that distinguishes between head waves and following waves, adjusting vessel speed and attitude to stabilize the hull by temporarily reducing speed during head waves and maintaining speed during following waves, using attitude and speed controls.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the vessel speed is temporarily reduced each time the marine vessel rides over a wave, then the up-and-down attitude change of the hull is reduced and hull stability is improved, but when following waves are occurring, the hull tends to become unstable and the vessel speed should not be reduced
Solution Approach 1:
The controller changes the vessel speed parameter dynamically based on wave direction detection. When head waves are detected, the vessel speed is temporarily reduced to stabilize the hull. When following waves are detected, the vessel speed is maintained to prevent hull instability. This parameter change approach allows the system to adapt control strategies to different wave conditions, resolving the contradiction between improving hull stability and maintaining adaptability.
Solution Approach 2:
The system implements dynamic control by continuously monitoring wave conditions and adjusting the vessel speed in real-time. The controller detects wave direction and dynamically modifies the speed reduction strategy accordingly - applying speed reduction for head waves while avoiding it for following waves. This dynamic adaptation enables the system to maintain optimal hull stability across varying wave conditions.
2Device complexity
If simple control is performed taking into account only the magnitude of the impact that the hull receives, then the control system is simple, but appropriate control is not sufficiently performed according to the wave condition and the stability of the hull is not sufficiently maintained
Solution Approach 1:
The system introduces an up-and-down movement sensor as an intermediary device to detect wave conditions and provide feedback to the controller. This sensor acts as a mediator between the physical wave environment and the control system, enabling the controller to make informed decisions about speed adjustment. The addition of this sensing intermediary allows for more sophisticated control while maintaining a relatively simple overall system architecture.
Solution Approach 2:
The controller uses feedback from the up-and-down movement sensor to continuously monitor hull motion and wave conditions. Based on this feedback, the controller adjusts the vessel speed appropriately - reducing speed when head waves are detected to improve stability. This feedback mechanism enables the system to achieve better hull stability without requiring complex control logic, as the sensor provides real-time information about actual wave impact conditions.
3Stability of the object's composition
If the vessel speed is reduced during following waves, then the hull may become unstable, but if the vessel speed is maintained, then the ride comfort during head waves deteriorates
Solution Approach 1:
The controller dynamically changes the vessel speed parameter based on detected wave direction. When head waves are detected, the system reduces vessel speed to minimize impact and improve ride comfort. When following waves are detected, the system maintains vessel speed to prevent hull instability. This conditional parameter adjustment resolves the contradiction by applying different speed control strategies to different wave conditions.
Solution Approach 2:
The system implements dynamic speed control that adapts to real-time wave conditions. The controller continuously monitors wave direction and dynamically adjusts the speed reduction strategy - applying speed reduction during head waves to reduce impact while maintaining speed during following waves to ensure stability. This dynamic approach allows the system to optimize both ride comfort and hull stability across varying sea states.
Data Source
AI summary
A marine propulsion system includes a propulsion device, an up-and-down movement sensor, and a controller configured or programmed to control driving of the propulsion device and perform a wave control including an attitude control to reduce an up-and-down attitude change of a hull by temporarily reducing a vessel speed based on a measurement result of the up-and-down movement sensor each time a marine vessel rides over a wave. The controller is configured or programmed to, in the wave control, perform the attitude control when it is determined that a wave condition is a head wave, and not perform the attitude control when it is determined that the wave condition is a following wave.