Engine Control Device Combustion State Adaptation

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Solution Overview

Problem

Existing engine control devices face challenges in preventing excessive engine speed at startup due to inadequate consideration of combustion states, leading to prolonged starting periods and delayed control responsiveness.

Innovation Solution

A control device that uses the crank angle cycle ratio to quantify the combustion state and adjust ignition timing and fuel injection amounts, ensuring responsive engine speed control and reduced exhaust emissions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If ignition timing is retarded to suppress excessive engine speed at startup, then engine speed control is improved, but starting performance deteriorates

Engineering Contradiction:
Improveengine speed controlVSAvoidstarting performance
Core Design Contradiction:
SpeedVSReliability

Solution Approach 1:

The patent applies parameter changes by dynamically adjusting ignition timing based on the detected combustion state. When combustion is strong, ignition timing is retarded to suppress excessive engine speed. When combustion is weak, ignition timing is advanced or maintained to ensure reliable starting. This conditional parameter adjustment resolves the contradiction between speed control and starting performance.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent implements feedback control by detecting the combustion state (through crank angle sensor signals or other combustion indicators) and using this information to adjust ignition timing in real-time during the startup phase. This closed-loop feedback mechanism enables the system to adapt ignition timing to actual combustion conditions, simultaneously achieving engine speed control and maintaining starting performance.

Inventive Principle:
Principle #23Feedback

2Adaptability or versatility

If area-based engine speed calculation is used for ignition timing correction, then combustion state adaptation is improved, but control responsiveness deteriorates

Engineering Contradiction:
Improvecombustion state adaptationVSAvoidcontrol responsiveness
Core Design Contradiction:
Adaptability or versatilityVSSpeed

Solution Approach 1:

The patent replaces the mechanical integration method (area calculation over time) with a direct detection and calculation method. Instead of calculating the area under the engine speed curve, the system directly detects combustion state parameters (such as crank angle sensor signal characteristics) and calculates the required ignition timing correction immediately. This substitution of measurement method maintains combustion state adaptation while dramatically improving control responsiveness.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentEP2405122B1Control device for internal combustion engine
Publication Date: 2019.06.05 HITACHI AUTOMOTIVE SYST LTD
  • EP2405122B1 patent drawingFigure 1
  • EP2405122B1 patent drawingFigure 2~3
  • EP2405122B1 patent drawingFigure 4~5

AI summary

Even when an engine is started in various combustion states, an excessive increase in engine speed at the start of the engine is suppressed without an influence of the combustion states and with an excellent responsiveness. Ignition timing (or a combustion injection amount) at the start of an internal combustion engine is corrected in accordance with a crank angle cycle ratio which is a ratio of a combustion period crank angle cycle and a reference crank angle cycle.