Marine Engine Speed Control for Smooth Mode Transition
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Solution Overview
Problem
Existing systems for controlling the rotational speed of internal combustion engines in marine propulsion devices experience a sharp decrease in vessel speed when transitioning from trolling mode to non-trolling mode, leading to undesirable deceleration and operator discomfort.
Innovation Solution
A system and method that utilize a controller communicating with operator input devices, such as a throttle lever and joystick, to manage the engine speed transition by ensuring the second operator-selected engine speed is greater than the current speed and requiring a threshold input, allowing a seamless transition from trolling to non-trolling mode by mapping user inputs directly to engine speed setpoints and using feed-forward signals to adjust the throttle valve position.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the engine transitions directly from trolling mode to non-trolling mode, then the engine speed changes rapidly to reach the new operating point, but this causes a sharp decrease in vessel speed leading to operator discomfort
Solution Approach 1:
The system performs preliminary action by detecting the operator's intent to transition modes through threshold input on the second input device, then proactively manages the speed transition by comparing selected speed with current speed and controlling the intermediate steps, preventing the sharp speed drop before it occurs
Solution Approach 2:
The controller continuously monitors current engine speed and compares it with the selected speed, using this feedback to determine whether to allow mode transition and to control the throttling process, ensuring the transition follows a path that maintains operator comfort
2Loss of time
If the controller allows immediate mode transition, then the system responds quickly to operator input, but this results in sudden engine speed drops and vessel deceleration
Solution Approach 1:
The controller uses feedback from comparing selected speed with current speed to determine whether to allow immediate transition or to implement controlled throttling, ensuring the transition maintains reliability while responding to operator input
Solution Approach 2:
The system changes the parameter of engine speed control by implementing different transition behaviors based on the relationship between selected and current speeds, allowing immediate transition when appropriate and controlled throttling when needed to maintain smooth operation
Data Source
AI summary
A system for controlling a rotational speed of a marine internal combustion engine has a first operator input device for controlling a speed of the engine in a trolling mode, in which the engine operates at a first operator-selected engine speed so as to propel a marine vessel at a first non-zero speed. A second operator input device controls the engine speed in a non-trolling mode, in which the engine operates at a second operator-selected engine speed so as to propel the marine vessel at a second non-zero speed. A controller is in signal communication with the first operator input device, the second operator input device, and the engine. In response to an operator request to transition from the trolling mode to the non-trolling mode, the controller determines whether to allow the transition based on the second operator-selected engine speed and a current engine speed.