Marine Thruster Control System for Low-Speed Maneuvering
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Solution Overview
Problem
Existing marine vessel thruster systems lack efficient control mechanisms, particularly at lower speeds and in situations with limited space, where rudder effectiveness decreases, and thruster operation is not optimally integrated with vessel speed and ballasting systems.
Innovation Solution
A thruster system with a controller that receives helm inputs to automatically operate thrusters, distinguishing between forward and aft directions, and adjusting based on vessel speed and ballast levels, while allowing manual control options and incorporating a crossover device to prevent cavitation through exhaust port management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a rudder is used as the primary steering mechanism, then the vessel can be steered effectively at higher speeds, but the rudder effectiveness decreases at lower speeds and when making sternway
Solution Approach 1:
The patent combines the rudder steering mechanism with a separate thruster system into an integrated control system. The thrusters are positioned to work in conjunction with the rudder, providing additional lateral force that supplements rudder effectiveness, particularly at low speeds and when making sternway, thereby resolving the contradiction between speed and rudder effectiveness.
Solution Approach 2:
The thruster system acts as an intermediary mechanism that bridges the gap in steering effectiveness. When the rudder alone is insufficient (at low speeds or sternway), the thrusters provide the necessary lateral propulsion to achieve desired vessel movement, effectively mediating the steering control across all operating conditions.
2Ease of operation
If thrusters are added to improve low-speed maneuverability, then handling at lower speeds improves, but the system complexity and control difficulty increase
Solution Approach 1:
The thruster system is designed to perform multiple functions: it provides lateral propulsion for low-speed maneuvering, assists with sternway handling, and works in conjunction with the rudder for overall vessel control. This multi-functionality justifies the added complexity by delivering comprehensive performance improvements across various operating conditions.
Solution Approach 2:
The control system automatically coordinates thruster operation with rudder commands, reducing the manual control burden on the operator. The system self-regulates the interaction between thrusters and rudder based on detected vessel state and steering inputs, thereby managing the inherent complexity without proportionally increasing operational difficulty.
3Temperature
If exhaust ports are positioned below the waterline for cooling, then engine cooling efficiency improves, but thruster cavitation occurs during operation
Solution Approach 1:
The exhaust system is segmented into separate pathways: one exhaust port positioned below the waterline for optimal cooling when the thruster is not operating, and another exhaust port positioned above the waterline to prevent cavitation when the thruster is operating. The system selectively activates the appropriate exhaust pathway based on thruster operation state, resolving the contradiction between cooling efficiency and thruster reliability.
Data Source
AI summary
A boat comprises a hull, a primary steering mechanism carried by the hull, a control station located on the hull, a helm located at the control station, and a thruster system carried by the hull. The primary steering mechanism, such as a rudder, is operable via the helm with a helm input being derived from operation of the primary steering mechanism thereby. The thruster system includes at least one thruster mounted to the hull, distinct from the primary steering mechanism, and a controller. The controller receives the helm input and is configured with program instructions to operate the at least one thruster responsive to the helm input to supplement a corresponding movement of the hull. The controller can also automatically operate the thruster responsive to direction, speed and ballast inputs.