Fuel Injection Controller Pilot Injection Learning
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Solution Overview
Problem
Existing fuel injection controllers struggle to determine the optimum pilot injection quantity due to variations in ignition timing and cetane number, leading to issues with combustion noise, emission, and smoke production, as they rely on detecting ignition timing of the main injection rather than directly analyzing combustion waveforms.
Innovation Solution
A fuel injection controller that learns the optimum pilot injection quantity by varying the pilot injection quantity based on ignition timing and ignition delay time, using an electronic control unit (ECU) to adjust the fuel injection system and detect the most suitable pilot injection quantity within a specified range, thereby stabilizing the ignition timing and delay time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the pilot injection quantity is increased to advance the ignition timing of the main injection, then the combustion noise and NOx are reduced, but the combustion noise increases and smoke is generated due to excessive pilot injection quantity
Solution Approach 1:
The patent applies feedback control by detecting the ignition timing of the main injection and using this information to adjust the pilot injection quantity. The ECU continuously monitors the ignition timing and modifies the pilot injection amount to maintain optimal combustion characteristics, thereby reducing both combustion noise and NOx while preventing excessive smoke generation.
Solution Approach 2:
The patent changes the pilot injection quantity parameter based on detected ignition timing variations. By dynamically adjusting this parameter in response to measured combustion characteristics, the system optimizes the balance between reducing NOx and preventing excessive smoke and combustion noise.
2Object-generated harmful factors
If the pilot injection quantity is decreased to reduce smoke and combustion noise, then the smoke and combustion noise are reduced, but the ignition timing of the main injection is retarded causing deteriorated emission and increased combustion noise
Solution Approach 1:
The feedback mechanism detects when ignition timing is retarded and responds by increasing the pilot injection quantity to advance the ignition timing back to the optimal range, thereby preventing emission deterioration and excessive combustion noise while maintaining reduced smoke levels.
Solution Approach 2:
The system dynamically adjusts the pilot injection quantity parameter in response to detected combustion characteristics, increasing it when ignition timing retards to maintain optimal emission levels and combustion noise control.
3Object-generated harmful factors
If the pilot injection quantity is controlled based on ignition timing of the main injection to avoid excessive smoke, then the smoke is reduced, but the optimum pilot injection quantity cannot be established due to variations in cetane number and fuel injector characteristics
Solution Approach 1:
The feedback control system continuously monitors ignition timing and uses this information to compensate for variations in cetane number and fuel injector characteristics. By adjusting the pilot injection quantity based on actual measured ignition timing rather than fixed predetermined values, the system maintains optimal combustion across different fuel and injector variations.
Solution Approach 2:
The system transitions from static predetermined pilot injection quantities to dynamic adjustment based on real-time ignition timing detection. This allows the pilot injection quantity to adapt to varying operating conditions, fuel properties, and injector characteristics, establishing the optimum quantity for each specific situation.
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
This approach allows for the establishment of an optimum pilot injection quantity that maintains ignition timing and delay time within a specified range, reducing combustion noise and improving emission quality by directly addressing variations in cetane number and fuel injector characteristics.
Implementation Method 1
the ECU 50 detects an ignition timing of the main injection based on a signal from the in-cylinder pressure sensor 42
Data Source
AI summary
A fuel injector performs a main injection and a pilot injection prior to the main injection. A fuel injection controller detects an ignition timing of a fuel injected at the main injection, detects a driving condition of the internal combustion engine, and varies a pilot injection quantity of the pilot injection when the driving condition is stable. Furthermore, the controller detects a variation in ignition timing due to a variation in the pilot injection quantity, and learns the pilot injection quantity based on the variation in ignition timing due to the variation in the pilot injection quantity.