Watercraft Propulsion Control for Precise Lateral Hull Translation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing watercraft propulsion systems face challenges in efficiently translating and maneuvering the hull without unwanted bow turning, particularly when using propulsion devices on the stern, as existing calibration methods are not suitable for systems without rudders.
Innovation Solution
A watercraft propulsion system that controls the bow thruster and stern propulsion devices to ensure their propulsive forces cross at a specific point, adjusting their output and steering angles to achieve lateral translation while balancing moments, with a controller optimizing these parameters based on user commands.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the propulsive force action lines of the stern propulsion devices are made to cross each other in the hull to achieve lateral translation, then the hull translation precision is improved, but the system complexity increases due to the need for coordinated control of multiple propulsion devices
Solution Approach 1:
The patent combines the bow thruster and stern propulsion devices into a unified control system that operates in coordination. The controller integrates control signals for both the bow thruster and stern propulsion devices, merging their functions to achieve precise lateral translation while canceling unwanted bow turning moments through coordinated operation.
Solution Approach 2:
The system dynamically adjusts the steering angles and propulsive forces of the stern propulsion devices based on real-time operational conditions. The controller continuously optimizes the crossing point of propulsive force action lines and the distribution of thrust between devices to maintain precise hull translation while adapting to changing loads and sea conditions.
2Measurement precision
If the steering angles of the stern propulsion devices are adjusted to balance the bow turning moment with the bow thruster, then the hull translation accuracy is improved, but the maneuverability response time may be reduced due to the need for moment balancing
Solution Approach 1:
The system performs preliminary calibration to determine the optimal crossing point of propulsive force action lines and the corresponding steering angles for the stern propulsion devices. This pre-established configuration allows the controller to quickly execute translation maneuvers by directly applying the calibrated parameters without requiring iterative moment balancing during actual operation.
Solution Approach 2:
The controller incorporates feedback mechanisms that monitor the actual hull movement and bow turning behavior in real-time. Based on this feedback, the controller dynamically adjusts the steering angles and thrust distribution of the stern propulsion devices to maintain accurate lateral translation while minimizing response time through adaptive optimization.
3Force
If one stern propulsion device is driven forward and another in reverse to generate lateral propulsive force, then the lateral translation capability is improved, but the energy consumption increases due to the opposing drive directions
Solution Approach 1:
The system optimizes the propulsive force parameters of the stern propulsion devices by adjusting their steering angles and thrust magnitudes. The controller calculates the optimal parameter combination that achieves the required lateral propulsive force while minimizing energy consumption, taking into account the opposing drive directions necessary for lateral movement.
Solution Approach 2:
The stern propulsion devices are designed to perform multiple functions: generating lateral propulsive force for translation, creating bow turning moments for orientation control, and providing propulsion in forward and reverse directions. This multi-functionality allows the system to use the same devices for both translation and steering, reducing the need for additional dedicated components and optimizing energy utilization across different operational modes.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The system enables precise hull translation with minimal bow turning, enhancing maneuverability and responsiveness to user inputs, allowing for efficient and controlled lateral movement.
Implementation Method 1
two engines that respectively rotate port-side and starboard-side forward/reverse propellers
Implementation Method 2
a side thruster that generates a lateral propulsive force
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A watercraft propulsion system (100) includes a bow thruster (BT), at least two propulsion devices (OM), a translation/bow turning operator (8) to apply a translation command to translate a hull (2) and a bow turning command to turn a bow of the hull (2), and a controller (50) configured or programmed to drive the bow thruster (BT), and drive one of the at least two propulsion devices (OM) forward and another of the at least two propulsion devices (OM) in reverse while controlling the steering angles of the at least two propulsion devices (OM) so that propulsive force action lines (71s, 71p) of the at least two propulsion devices (OM) cross each other in the hull (2) in a translation watercraft maneuvering mode to translate the hull (2) in response to an operation of the translation/bow turning operator (8). The controller (50) includes a calibration mode in which calibration is performed for the translation watercraft maneuvering mode.