Rudder Load Control for Stable Ship Steering in Waves
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Solution Overview
Problem
Existing ship steering control systems face inefficiencies due to disturbances from natural phenomena like currents and waves, leading to frequent rudder adjustments and increased travel distance, as they struggle to maintain a stable course.
Innovation Solution
A ship steering control device that calculates an angle difference between the ship's course and target direction, measures propeller rotation speed, and adjusts the rudder load to match a target load, thereby controlling the rudder angle to compensate for disturbances and improve navigation efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If feedback control is performed to match the current rudder angle to the determined rudder angle, then the ship can be steered toward the target point, but the ship sails in a meandering manner and travels an unnecessarily long distance due to frequent rudder adjustments caused by disturbances
Solution Approach 1:
The system calculates a target rudder angle in advance based on the angle difference between current course and target direction, then determines the optimal rudder angle by learning from historical data and marine conditions before actual steering action is taken. This preliminary determination allows the ship to maintain a more direct course while still responding to disturbances.
Solution Approach 2:
The system changes the control parameter from direct rudder angle control to rudder angle determination based on learned empirical rules and marine conditions. By using machine learning to optimize the rudder angle determination, the system achieves better course keeping with fewer adjustments, improving navigation efficiency while maintaining reliability.
2Adaptability or versatility
If the rudder angle is frequently adjusted to maintain optimal course against changing natural phenomena, then the ship can respond to disturbances, but the operation efficiency of the rudder is degraded
Solution Approach 1:
The system continuously monitors marine conditions and ship response, using this feedback to update the learned empirical rules for rudder angle determination. This adaptive feedback mechanism allows the system to maintain high adaptability to changing conditions while optimizing rudder operation efficiency through data-driven decision making.
Solution Approach 2:
The system uses machine learning to automatically determine optimal rudder angles based on learned empirical rules, reducing the need for frequent manual or automated adjustments. The learned model serves itself by continuously improving its performance through accumulated operational data, thereby enhancing both adaptability and efficiency.
3Adaptability or versatility
If machine learning is used to determine rudder angle according to various marine conditions, then the control can adapt to natural phenomena, but the rudder still needs to be frequently turned to maintain optimal course
Solution Approach 1:
The system performs preliminary determination of the optimal rudder angle by calculating the angle difference and applying learned empirical rules before executing the steering action. This advance calculation reduces the frequency and time of rudder adjustments while maintaining adaptive response to marine conditions.
Solution Approach 2:
The system dynamically adjusts the rudder angle determination strategy based on the learned empirical rules and current marine conditions. By making the control system dynamic and adaptive rather than static, it reduces unnecessary frequent adjustments while maintaining responsiveness to actual environmental changes.
Data Source
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AI summary
A controller (1) calculates an angle difference between a course of a ship (10) and a target direction, calculates a target load serving as a target load to be applied to a rudder (4) based on the calculated angle difference, measures a load on the rudder (4), and controls a ship steering machine (6) for turning the rudder (4) to match the measured load on the rudder (4) to the calculated target load.