Fuel Injection Control for Engine Pressure Compensation
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Solution Overview
Problem
Existing fuel supply apparatuses for internal combustion engines struggle to accurately control fuel injection amounts, especially in group injection modes, due to neglecting pressure changes during fuel injection valve operation, leading to inefficiencies in engine output torque and air-fuel ratio.
Innovation Solution
A fuel supply apparatus with fuel injection control means that adjusts fuel injection periods and parameters based on engine operating conditions, using reference and overlapped injection modes, and correction coefficients to compensate for pressure changes, ensuring accurate fuel injection amounts across different modes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If group injection mode is used to improve fuel injection efficiency, then fuel injection speed increases, but fuel injection amount control accuracy deteriorates due to pressure changes during overlapping injection periods
Solution Approach 1:
The ECU calculates and stores correction parameters before group injection occurs, based on predicted fuel pressure changes during overlapping injection periods. This preliminary preparation allows the system to compensate for pressure effects without real-time calculation delays, maintaining both high injection speed and accurate fuel amount control.
Solution Approach 2:
The system dynamically adjusts the fuel injection amount parameter (TOUTS, TOUTD) by applying correction parameters (TOVRLP) that account for fuel pressure changes during overlapping injection periods. This parameter modification enables accurate fuel control despite the pressure fluctuations inherent in group injection mode.
2Manufacturing precision
If sequential injection mode is used to maintain stable fuel pressure, then fuel injection control accuracy improves, but fuel injection efficiency deteriorates due to longer total injection periods
Solution Approach 1:
The ECU pre-calculates correction parameters for group injection mode based on engine operating conditions, storing them for rapid application when group injection is required. This eliminates real-time calculation overhead, allowing the system to switch to efficient group injection without sacrificing control accuracy.
Solution Approach 2:
The system dynamically selects between sequential and group injection modes based on engine operating conditions, and dynamically adjusts injection parameters using correction values. This dynamic adaptability allows the system to achieve both the stability of sequential injection and the efficiency of group injection as needed.
3Manufacturing precision
If correction parameters are calculated in real-time during overlapping injection, then fuel injection accuracy improves, but computational load and response time increase
Solution Approach 1:
The ECU calculates correction parameters in advance based on engine operating conditions (rotation speed, load, temperature) and stores them in memory. When group injection occurs, the system simply retrieves the pre-calculated correction parameter corresponding to the current condition, eliminating real-time computation and ensuring both accuracy and rapid response.
Solution Approach 2:
The system pre-determines correction parameters for various engine operating conditions and stores them in advance. During actual group injection, the ECU only needs to lookup and apply the appropriate pre-calculated correction parameter, avoiding complex real-time calculations while maintaining accurate fuel control.
Data Source
AI summary
A fuel supply apparatus for an internal combustion engine having a plurality of cylinders, which supplies fuel through fuel injection valves provided corresponding to the plurality of cylinders. An amount of fuel supplied to the engine is controlled by changing a fuel injection period of said fuel injection valve, and performing a fuel injection with a plurality of injection modes including a reference injection mode. A fuel injection amount parameter for controlling a valve opening period of the fuel injection valve in the reference injection mode, is calculated according to an operating condition of said engine. When the injection mode is determined to be another injection mode which differs from the reference injection mode, the fuel injection amount parameter is corrected so as to compensate shortage or oversupply of the fuel injection amount according to a correction parameter indicative of a time period which affects a pressure change of the fuel supplied to the fuel injection valve caused by employing the other injection mode.