Engine Controller Fuel Property Detection via Cylinder Speed Variation

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Solution Overview

Problem

Existing controllers for internal combustion engines face challenges in accurately determining fuel properties without deteriorating drivability, particularly due to uncertainties in ignition timing and low detection frequency, which can lead to unstable combustion conditions and poor emission and fuel economy.

Innovation Solution

A controller for a multicylinder engine that varies fuel injection conditions based on engine speed computations for both operation and non-operation cylinders, allowing for accurate fuel property determination without significantly affecting engine drivability, by using a computing means to assess engine speed variations and determining fuel properties through cylinder torque analysis.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If fuel injection condition is varied to detect fuel property, then fuel property determination accuracy is improved, but engine drivability deteriorates

Engineering Contradiction:

Improvefuel property determination accuracyVSAvoidengine drivability

Core Design Contradiction:

Measurement precisionVSEase of operation

Solution Approach 1:

The engine cylinders are divided into operation cylinders and non-operation cylinders. The fuel injection condition is varied only in the non-operation cylinders while maintaining normal injection in operation cylinders, allowing fuel property detection without significantly impacting overall engine drivability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The fuel injection condition variation is applied locally to specific non-operation cylinders rather than all cylinders. This localized approach enables fuel property determination while minimizing the impact on overall engine performance and drivability.

Inventive Principle:

Principle #3Local quality

2Productivity

If fuel injection is performed during vehicle deceleration to detect fuel property, then detection frequency is improved, but drivability is deteriorated

Engineering Contradiction:

Improvedetection frequencyVSAvoiddrivability

Core Design Contradiction:

ProductivityVSEase of operation

Solution Approach 1:

The system performs fuel property detection during normal engine operation by utilizing non-operation cylinders, rather than waiting for specific conditions like vehicle deceleration. This allows continuous or frequent detection without requiring the engine to be in a specific operating state, thereby maintaining both high detection frequency and good drivability.

Inventive Principle:

Principle #10Preliminary action

3Difficulty of detecting and measuring

If ignition timing is used to detect fuel property, then detection capability is improved, but measurement accuracy deteriorates due to uncertainty in ignition timing causes

Engineering Contradiction:

Improvefuel property detection capabilityVSAvoidfuel property measurement accuracy

Core Design Contradiction:

Difficulty of detecting and measuringVSMeasurement precision

Solution Approach 1:

The invention extracts the fuel property detection function from the ignition timing parameter, which is confounded by multiple factors. Instead, it directly measures the effect of varied fuel injection on engine speed in non-operation cylinders, isolating the fuel property effect from other influencing factors like ignition timing variations and EGR.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The engine speed variation in non-operation cylinders serves as an intermediary measurement that directly reflects fuel property effects. By measuring engine speed response to controlled fuel injection variations, the system obtains a more direct and accurate indication of fuel properties compared to using ignition timing as an indirect measure.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 accurate fuel property determination while minimizing the impact on engine drivability, improving combustion stability and reducing emissions by differentiating between high and low cetane fuels through controlled fuel injection patterns.

Implementation Method 1

a fuel injector 11 for injecting fuel into a cylinder

Methodology Applied

Scientific EffectCombustion: Combustion

Implementation Method 2

a computing means for computing an engine speed, which varies according to fuel combustion, with respect to each cylinder based on a time period which is required for a crankshaft to rotate a specified angle

Methodology Applied

Scientific EffectRotational motion measurement:

Data Source

PatentUS8977471B2Controller for internal combustion engine

Publication Date: 2015.03.10 DENSO CORP

AI summary

A multicylinder engine is provided with a fuel injector for each cylinder. An ECU defines a fuel injection condition of the fuel injector based on an engine driving condition and executes a fuel injection control for each cylinder based on the defined fuel injection condition. The ECU computes an engine speed with respect to each cylinder. While the engine is running, the fuel injection condition is operated in an operation cylinder. A fuel property is determined based on the engine speed of the operation cylinder and an engine speed of a non-operation cylinder.