Engine Fuel Injection Control for Sudden Load Increase
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Solution Overview
Problem
Existing engine control systems struggle to quickly increase fuel injection amount at appropriate timing when engine load increases from a low value, leading to insufficient air excess ratio, which can cause issues like increased toxic substances in exhaust gas and engine stalling.
Innovation Solution
An engine control device that switches between normal and load application control modes, using feedback and feedforward calculations to adjust fuel injection amounts based on engine speed and load changes, ensuring timely increases in fuel injection without insufficient air excess ratio.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the fuel injection amount is quickly increased to improve engine drive responsiveness, then the engine response speed is improved, but the air excess ratio becomes insufficient causing increased toxic emissions and decreased thermal efficiency
Solution Approach 1:
The control device performs preliminary action by detecting load application states (sudden increases in engine load) and proactively switching to load application control mode before the air excess ratio becomes insufficient. This anticipatory control prevents the harmful effect by preparing the appropriate fuel injection strategy in advance, rather than reacting after the problem occurs.
Solution Approach 2:
The system dynamically switches between two control modes (normal control and load application control) based on real-time detection of engine load changes. This dynamic adaptation allows the fuel injection amount to be optimally adjusted according to the current operating state, achieving both rapid response and adequate air excess ratio maintenance.
2Speed
If the fuel injection amount is quickly increased to improve engine drive responsiveness, then the engine response speed is improved, but the thermal efficiency decreases due to insufficient air excess ratio
Solution Approach 1:
The control device performs preliminary action by detecting load application states (sudden increases in engine load) and proactively switching to load application control mode before the air excess ratio becomes insufficient. This anticipatory control prevents the harmful effect by preparing the appropriate fuel injection strategy in advance, rather than reacting after the problem occurs.
Solution Approach 2:
The system dynamically switches between two control modes (normal control and load application control) based on real-time detection of engine load changes. This dynamic adaptation allows the fuel injection amount to be optimally adjusted according to the current operating state, achieving both rapid response and adequate air excess ratio maintenance.
3Speed
If the fuel injection amount is quickly increased to improve engine drive responsiveness, then the engine response speed is improved, but engine stalling occurs due to insufficient air excess ratio
Solution Approach 1:
The control device performs preliminary action by detecting load application states (sudden increases in engine load) and proactively switching to load application control mode before the air excess ratio becomes insufficient. This anticipatory control prevents the harmful effect by preparing the appropriate fuel injection strategy in advance, rather than reacting after the problem occurs.
Solution Approach 2:
The system dynamically switches between two control modes (normal control and load application control) based on real-time detection of engine load changes. This dynamic adaptation allows the fuel injection amount to be optimally adjusted according to the current operating state, achieving both rapid response and adequate air excess ratio maintenance.
4Speed
If the feedforward fuel injection amount is added to the basic fuel injection amount in normal operation, then the engine drive responsiveness is improved, but the air excess ratio becomes insufficient when the engine load is low
Solution Approach 1:
The system dynamically switches between two control modes (normal control and load application control) based on real-time detection of engine load changes. This dynamic adaptation allows the fuel injection amount to be optimally adjusted according to the current operating state, achieving both rapid response and adequate air excess ratio maintenance.
Solution Approach 2:
The control device changes the control parameter (fuel injection calculation method) based on the detected engine state. When a load application state is detected, the system switches to adding feedforward fuel injection amount to basic fuel injection amount, otherwise it uses only basic fuel injection amount, thereby adapting to different operating conditions.
Data Source
AI summary
An engine control device includes: an injection command unit for outputting a fuel injection amount command value; a first calculation unit for outputting a fuel injection amount obtained by FB calculation based on an engine speed deviation to the injection command unit as a basic fuel injection amount; and a second calculation unit for outputting a fuel injection amount obtained by FF calculation based on an engine load at present of an engine to the injection command unit as a FF fuel injection amount. The fuel injection amount command value switches from a fuel injection amount calculated based on the basic fuel injection amount by the injection command unit to a fuel injection amount calculated based on a value obtained by adding the FF fuel injection amount to the basic fuel injection amount, if it is determined that a load application state has occurred in which the engine load before a prescribed time, which is not greater than a prescribed value, increases by not less than a variation threshold.