Differential Thruster Piloting for Autonomous Surface Vessels
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Solution Overview
Problem
Existing unmanned marine surface vessels face challenges in reliable and power-efficient steering, as traditional steering mechanisms require powered mechanisms, increasing weight, complexity, and power consumption, and existing systems are designed for human operation rather than autonomous use.
Innovation Solution
A piloting system using a pair of independently controllable fixed thrusters on the outer hull, which coordinates thrust differentials to steer the vessel, allowing autonomous operation in straight line and circling modes, with automatic adjustment of thrust to maintain vessel trajectory and reduce power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional steering mechanisms (rudders or turnable thrusters) are used, then the vessel can be steered, but the weight, complexity, and power consumption increase
Solution Approach 1:
The steering function is segmented from the propulsion function. Instead of using a single integrated rudder or turnable thruster, the system uses multiple fixed thrusters (at least two) positioned at different locations on the vessel. Each thruster remains fixed in orientation while independently controllable, dividing the steering task across multiple simple units rather than one complex mechanism.
Solution Approach 2:
The steering and propulsion functions are merged into a single system using fixed thrusters. The same fixed thrusters that provide forward propulsion also enable steering through differential thrust control, eliminating the need for separate steering mechanisms like rudders or turnable thrusters.
2Reliability
If traditional steering mechanisms are used, then the vessel can be steered, but the power consumption increases
Solution Approach 1:
The steering and propulsion functions are merged into a single system using fixed thrusters. The same fixed thrusters that provide forward propulsion also enable steering through differential thrust control, eliminating the need for separate steering mechanisms like rudders or turnable thrusters.
Solution Approach 2:
The system dynamically adjusts the thrust of individual fixed thrusters based on steering requirements. By varying the thrust differential between thrusters in real-time, the system achieves steering without mechanical movement, reducing energy consumption compared to powered steering mechanisms that must continuously overcome mechanical resistance.
3Device complexity
If fixed thrusters with coordinated thrust differential are used, then weight and complexity are reduced, but autonomous piloting capability is limited
Solution Approach 1:
The piloting system incorporates feedback loops that continuously monitor vessel position, orientation, and thruster performance. This feedback enables autonomous operation by allowing the control system to automatically adjust thrust differentials to maintain desired course and position, eliminating the need for constant human intervention while using the simple fixed thruster configuration.
Solution Approach 2:
The system is designed to perform piloting functions autonomously without requiring a human operator physically present on the vessel. The control system automatically processes navigation data, calculates required thrust adjustments, and commands the fixed thrusters accordingly, enabling the vessel to pilot itself through programmed routes and respond to environmental conditions.
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 robust, reliable, and energy-efficient steering of unmanned marine vessels, reducing operational costs and improving safety by eliminating the need for human operators and minimizing power consumption, while allowing for extended ocean data collection missions.
Implementation Method 1
a first thruster and a second thruster attached to the vessel, the first thruster and second thruster spaced apart from each other
Data Source
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AI summary
The present teachings relate to a piloting system for an unmanned marine vessel having a first thruster and a second thruster attached to the vessel, the first thruster and second thruster spaced apart from each other, wherein the system is configured to pilot the vessel in a straight line mode of operation in which the vessel autonomously tracks a line between two waypoints and a circling mode of operation in which the vessel autonomously tracks a circle around a waypoint, wherein when the vessel is piloted in said straight line mode, the system controls the overall thrust level applied to the first and second thrusters and the thrust differential between the first and second thrusters to maintain the vessel on the line, and wherein when the vessel is piloted in said circling mode, the system controls the overall thrust level applied to the first and second thrusters and the thrust differential between the first and second thrusters to maintain the vessel on the circle.