Ship Autopilot Turning Center Accuracy via Dynamic Rudder Feedback
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Solution Overview
Problem
Conventional autopilots for ships fail to accurately turn around a desired turning center position due to external factors like tidal currents, resulting in unpredictable ship paths and increased workload for steersmen, as they lack the capability to adjust rudder angles based on real-time ship positioning.
Innovation Solution
An automatic steering control apparatus equipped with a positioning device that measures the ship's position, allowing for input and storage of desired turning center and radius, and a rudder angle adjuster that calculates and outputs commands to maintain a turning arc around the specified center, unaffected by external factors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If conventional autopilot uses constant rudder angle for turning, then the turning operation is simple to perform, but the ship cannot turn around a fixed point due to drift from extraneous factors
Solution Approach 1:
The autopilot system continuously receives feedback from the positioning device about the ship's actual position and calculates the distance to the turning center. Based on this feedback, the rudder angle adjuster dynamically adjusts the rudder angle to maintain the ship on the correct turning arc, compensating for drift caused by extraneous factors like tidal currents.
Solution Approach 2:
The patent replaces the conventional mechanical steering system with constant rudder angle with an automated control system that uses positioning devices, microprocessors, and algorithms to calculate and adjust rudder angle in real-time, enabling precise turning around a fixed point despite environmental disturbances.
2Extent of automation
If conventional autopilot adjusts rudder angle to follow target bearing, then course change can be performed automatically, but stationary deviation and overshoot occur causing unpredictable paths
Solution Approach 1:
The system dynamically adjusts the rudder angle based on the ship's current position relative to the turning center and the desired turning radius. Instead of following a fixed target bearing, the rudder angle is continuously modified to keep the ship on the correct circular arc, eliminating stationary deviation and overshoot.
Solution Approach 2:
The patent changes the control parameter from fixed target bearing to dynamic turning radius maintenance. The rudder angle adjuster modifies the rudder angle based on the calculated distance from the turning center and the desired arc trajectory, ensuring accurate course change without deviation or overshoot.
3Strength
If conventional autopilot uses limiter to prevent large load on steering, then steering system is protected from excessive load, but smooth automatic course change cannot be achieved
Solution Approach 1:
The system dynamically adjusts the rudder angle in a controlled manner based on the ship's position and motion characteristics. By calculating the optimal rudder angle to maintain the turning arc, the system achieves smooth course change while keeping the rudder movements within safe operational limits, eliminating the need for restrictive limiters.
Data Source
AI summary
An object of the present invention is to provide an automatic steering control apparatus, including an autopilot, which enables a ship to turn around a desired fixed point as a turning center with a desired turning radius without being affected by an extraneous factor, such as a tidal current or the like.To achieve the object, a center position, a turning radius and a turning direction for turning are initially designated by the operator, a tangent to a turning circle at an intersection of a straight line from the turning center to a position of the ship and the turning circle, and a course of the ship is controlled to approach the tangent.