Marine Engine Control System for Smooth Gear Shifting

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Solution Overview

Problem

Conventional marine propulsion systems experience noise, gear degradation, and engine stalling due to high engine speeds during gear shifting, leading to undesirable shock forces and potential drive component failure.

Innovation Solution

An engine control system that delays gear shifts until the engine speed is reduced below a threshold for a predetermined time, using a controller connected to a shifter and throttle control to manage engine speed and prevent shifts until the speed stabilizes, thereby reducing shock and noise.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If gear shifting is performed at high engine speeds, then shifting speed is improved, but shock forces and noise increase causing drive component failure

Engineering Contradiction:

Improveshifting speedVSAvoidshock forces and noise

Core Design Contradiction:

SpeedVSObject-affected harmful factors

Solution Approach 1:

The control system performs preliminary action by detecting a shift request and delaying the actual gear shift execution until engine speed reduces below a threshold. This preliminary delay allows the engine to naturally decelerate, ensuring the shift occurs at optimal speed conditions, thereby preventing shock forces and noise while maintaining responsive shifting

Inventive Principle:

Principle #10Preliminary action

2Object-affected harmful factors

If gear shifting is delayed to reduce engine speed, then shock forces and noise are reduced, but shifting response time increases

Engineering Contradiction:

Improveshock forces and noiseVSAvoidshifting response time

Core Design Contradiction:

Object-affected harmful factorsVSLoss of time

Solution Approach 1:

The control system continuously monitors engine speed and uses feedback to determine when to execute the delayed shift. The system only permits the shift after confirming engine speed has reduced below the threshold, creating a closed-loop control that balances noise reduction with responsive shifting by adapting to real-time engine conditions

Inventive Principle:

Principle #23Feedback

3Stability of the object's composition

If engine speed is maintained at predetermined level for predetermined time, then gear shifting smoothness is improved, but engine operation flexibility is reduced

Engineering Contradiction:

Improvegear shifting smoothnessVSAvoidengine operation flexibility

Core Design Contradiction:

Stability of the object's compositionVSAdaptability or versatility

Solution Approach 1:

The control system dynamically adjusts engine operation by temporarily maintaining speed for shift smoothness, then immediately transitioning to follow the throttle position after shift completion. This dynamic behavior provides temporary stability during shifting while preserving overall operational flexibility through post-shift throttle following

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS10234031B2Engine control system and method

Publication Date: 2019.03.19 CUMMINS INTELLECTUAL PROPERTY INC

AI summary

An engine control strategy for a marine vessel propulsion system receives a request for a gear from among plural transmission gears, determines an engine speed for the requested transmission gear shift, adjusts the engine to the determined speed for a predetermined amount of time, and prevents the requested transmission gear shift from occurring for the predetermined amount of time while maintaining the engine at the predetermined speed. After the predetermined amount of time elapses, the requested shift is allowed to occur.