Marine Engine Control Module for Lean Burn Mode Transitions

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Solution Overview

Problem

Existing marine internal combustion engine control systems face challenges in efficiently transitioning between stoichiometric and lean burn operations, particularly in managing fuel-air equivalence ratios to optimize fuel economy while maintaining engine efficiency, emissions control, and drivability.

Innovation Solution

The implementation of a control module that uses separate sets of mapped parameter values and feedback controllers to adjust combustion parameters, such as spark timing, air quantity, and fuel quantity, allowing seamless transitions between stoichiometric and lean burn modes by scheduling these adjustments based on engine operating conditions and operator demands.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If the engine operates at lean burn limits to improve fuel economy, then fuel efficiency is improved, but engine stability and drivability deteriorate

Engineering Contradiction:

Improvefuel economyVSAvoidengine stability

Core Design Contradiction:

Use of energy by moving objectVSReliability

Solution Approach 1:

The control module continuously monitors engine operating parameters including manifold absolute pressure, engine speed, and temperature sensors to detect deviations from optimal lean burn operation. This feedback enables real-time adjustments to fuel injection timing and quantity, maintaining stable combustion at lean burn limits while maximizing fuel efficiency.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The system dynamically transitions between stoichiometric and lean burn modes based on real-time sensor inputs and operating conditions. The control module adjusts combustion parameters on-the-fly, allowing the engine to operate at the edges of lean burn limits when conditions permit, while automatically retreating to stable stoichiometric operation when stability concerns arise, thus resolving the contradiction between fuel economy and stability.

Inventive Principle:

Principle #15Dynamics

2Use of energy by moving object

If the engine transitions between stoichiometric and lean burn modes to optimize fuel economy, then fuel efficiency is improved, but drivability and torque stability deteriorate

Engineering Contradiction:

Improvefuel efficiencyVSAvoiddrivability

Core Design Contradiction:

Use of energy by moving objectVSEase of operation

Solution Approach 1:

The control module anticipates transitions between operating modes by monitoring trends in sensor data and proactively adjusting combustion parameters before actual mode changes occur. This preliminary action smooths the transition process, preventing abrupt changes in torque output that would affect drivability, while still enabling the fuel efficiency benefits of lean burn operation.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system employs separate sets of mapped parameter values for different operating modes (stoichiometric vs. lean burn) and smoothly interpolates between them during transitions. By carefully managing changes in fuel injection timing, air quantity, and spark timing parameters, the system maintains stable torque output and smooth drivability while achieving fuel efficiency improvements through mode transitions.

Inventive Principle:

Principle #35Parameter changes

3Use of energy by moving object

If separate sets of mapped parameter values are used for stoichiometric and lean burn modes to achieve optimal fuel economy, then fuel efficiency is improved, but system complexity increases

Engineering Contradiction:

Improvefuel economyVSAvoidcontrol system complexity

Core Design Contradiction:

Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The control module serves multiple functions: it manages both stoichiometric and lean burn modes, processes data from multiple sensors, performs real-time calculations for fuel injection timing and quantity, and executes mode transitions. This multi-functionality consolidates what could be separate systems into a single integrated control unit, achieving optimal fuel economy through multiple operating modes without proportionally increasing overall system complexity.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS10094321B1Method for controlling a marine internal combustion engine

Publication Date: 2018.10.09 BRUNSWICK CORP

AI summary

Controlling a marine engine includes operating the engine according to an initial set of mapped parameter values to achieve a first target fuel-air equivalence ratio, determining a first actual fuel-air equivalence ratio, and using a feedback controller to minimize a difference between the first target and actual ratios. Feedback controller outputs are used to populate an initial set of adapt values to adjust combustion parameter values from the initial set of mapped parameter values. The method includes transitioning to operating the engine according to a subsequent set of mapped parameter values to achieve a different target fuel-air equivalence ratio. The method includes determining a second actual fuel-air equivalence ratio, using the feedback controller to minimize a difference between the second target and actual ratios, and using feedback controller outputs to populate a subsequent set of adapt values to adjust combustion parameter values from the subsequent set of mapped parameter values.