Outboard Motor Toe Angle Control for Marine Vessel Steering
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Solution Overview
Problem
Existing marine vessel steering systems with outboard motors face increased power consumption during straight travel due to external forces from water streams, which require higher motor torques and thus higher electric currents, leading to inefficient energy use.
Innovation Solution
A marine vessel steering system that controls the toe angle between outboard motors during straight travel to minimize electric currents flowing through the motors, reducing external forces and improving performance by setting the toe angle to a specific 'straight traveling toe angle' that minimizes power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the toe angle is maintained at a standard neutral position during straight travel, then the steering stability is improved, but the external force from water streams increases requiring higher motor torque and electric current consumption
Solution Approach 1:
The patent changes the toe angle parameter from a standard neutral position (0 degrees) to a specific optimized value during straight travel. This parameter modification reduces the external force from water streams acting on the outboard motors, thereby decreasing the motor torque and electric current required to maintain steering stability, directly resolving the contradiction between steering stability and energy consumption.
2Measurement precision
If higher motor torque is applied to counteract external water stream forces, then the steering control precision is improved, but the power consumption increases significantly
Solution Approach 1:
The patent optimizes the toe angle parameter to a specific value that minimizes external water stream forces. This reduction in external forces decreases the motor torque required for steering control, thereby maintaining steering control precision while significantly reducing power consumption, effectively resolving the contradiction between control precision and power usage.
3Device complexity
If the outboard motors are kept in a parallel alignment during straight travel, then the structural simplicity is maintained, but the energy efficiency deteriorates due to increased external forces
Solution Approach 1:
The patent modifies the toe angle parameter from a parallel alignment (0 degrees) to an optimized angle configuration during straight travel. This parameter change reduces the external forces from water streams, improving energy efficiency without significantly increasing structural complexity, as the change involves only angular adjustment rather than structural modification.
Data Source
AI summary
A marine vessel steering system includes a basic target turning angle computing unit that computes a basic target turning angle δo* common to two outboard motors based on a steering angle θ detected by a steering angle sensor. A traveling state determining unit determines whether a traveling state of a marine vessel is a straight traveling state based on the received basic target turning angle δo*. When the traveling state of the marine vessel is determined as being the straight traveling state, a target turning angle computing unit determines, based on the basic target steering angle δo* and a straight traveling toe angle φs stored in a nonvolatile memory, target turning angles δ* of the two outboard motors such that a toe angle between the two outboard motors is equal to the straight traveling toe angle φs.