Vessel Propulsion Control for Trolling Speed
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Solution Overview
Problem
Existing vessel propulsion systems using internal combustion engines are limited in their ability to maintain constant speed travel at higher speeds during trolling, as they rely on stepwise adjustments of engine speed between upper and lower limits, resulting in insufficient propulsive force for higher speed requirements.
Innovation Solution
A vessel propulsion system that includes a throttle valve, an accelerator operation unit, and a control unit capable of varying engine output even when the throttle opening degree is maintained at a fixed value other than idling, allowing for fine adjustments of engine output through an output operation unit and control modes, including a trolling mode that adjusts ignition timing and bypass passage control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the target engine speed is adjusted between upper and lower limits based on idling engine speed, then the vessel can maintain constant speed travel at low speed or be held against tidal current, but the propulsive force is insufficient for higher speed travel
Solution Approach 1:
The invention changes the control parameter from fixed throttle opening degree to variable engine output control. By allowing the control unit to vary engine output independently of throttle position through ignition timing adjustment and air-fuel ratio control, the system achieves higher propulsive force while maintaining the ability to operate at low speeds for trolling applications.
2Ease of operation
If the throttle opening degree is maintained at a fixed value, then the accelerator operation is simplified, but the engine output cannot be varied for different propulsion requirements
Solution Approach 1:
The control unit acts as an intermediary between the accelerator operation unit and the engine output. It receives the accelerator operation signal and additionally processes ignition timing and air-fuel ratio control signals to vary engine output independently, thereby providing both simplified operation and enhanced adaptability without requiring additional manual controls.
3Device complexity
If stepwise adjustment of engine speed is used for trolling, then the control mechanism is simple, but the propulsion function is limited to low speed constant travel
Solution Approach 1:
The control unit is designed to perform multiple functions: it controls engine speed for basic trolling operations while also independently adjusting ignition timing and air-fuel ratio to provide variable engine output. This multi-functionality allows the same control mechanism to serve both simple trolling and higher speed propulsion requirements without increasing device complexity.
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
Enables efficient propulsion at higher speeds by allowing precise control of engine output, providing a more effective trolling propulsion function without the need for additional components, and allowing seamless transitions between ordinary and trolling modes.
Implementation Method 1
the control unit varies an ignition timing of the engine to vary the engine output when the throttle opening degree is maintained at the fixed value other than the idling opening degree
Data Source
AI summary
A vessel propulsion system includes an engine that provides a propulsive force to a vessel, a throttle valve to adjust an air amount supplied to the engine, an accelerator operation unit operated by an operator to adjust a throttle opening degree, the throttle opening degree corresponding to an operation amount of the accelerator operation unit, and a control unit programmed to vary an engine output even when the throttle opening degree is maintained at a fixed value other than an idling opening degree, the engine output corresponding to the operation amount of the accelerator operation unit as a reference output.