Engine Fuel Injection Control for Stable Synchronous Injection
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Solution Overview
Problem
Existing fuel injection systems in internal combustion engines struggle to maintain accurate synchronous injection amounts while reducing particulate matter (PM) and other exhaust gas emissions, particularly when factors such as fresh air intake, coolant temperature, and fuel vapor interference affect the injection process.
Innovation Solution
A controller that performs a base injection amount calculation, followed by a division process into synchronous and asynchronous injection amounts, with asynchronous injection being corrected using feedforward control to maintain stable synchronous injection, while compensating for disturbances and variations in fresh air intake, fuel vapor, and temperature.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If both synchronous injection amount and asynchronous injection amount are corrected according to the required correction amount, then the air-fuel ratio control is improved, but the synchronous injection amount cannot be maintained at an adequate value for reducing PN
Solution Approach 1:
The patent segments the injection amount correction into two independent parts: synchronous injection amount and asynchronous injection amount. The base injection amount is divided into these two components, and only the asynchronous injection amount is corrected according to the required correction amount, while the synchronous injection amount is kept uncorrected to maintain it at an adequate value for reducing PN.
Solution Approach 2:
The patent applies different correction strategies to different parts of the injection system: the synchronous injection amount is maintained without correction to ensure low PN, while the asynchronous injection amount is corrected to improve air-fuel ratio control. This local differentiation allows each component to optimize its specific function.
2Measurement precision
If the synchronous injection amount is corrected according to the required correction amount, then the air-fuel ratio control is improved, but it becomes difficult to sufficiently reduce PN
Solution Approach 1:
The patent segments the injection correction function, applying correction only to the asynchronous injection amount while leaving the synchronous injection amount uncorrected. This segmentation allows the synchronous injection to maintain its PN-reducing capability while the asynchronous injection handles air-fuel ratio control.
Solution Approach 2:
Different correction qualities are applied to different injection components: the synchronous injection maintains a fixed, adequate value optimized for PN reduction, while the asynchronous injection receives dynamic correction for air-fuel ratio management.
3Object-generated harmful factors
If the asynchronous injection amount is not corrected, then PN is reduced, but the air-fuel ratio control deteriorates
Solution Approach 1:
The patent assigns different functional responsibilities to different injection components: the synchronous injection amount is dedicated to PN reduction and remains uncorrected, while the asynchronous injection amount handles air-fuel ratio control and receives correction according to the required correction amount.
Solution Approach 2:
The synchronous injection is optimized locally for PN reduction without correction, while the asynchronous injection is optimized locally for air-fuel ratio control with dynamic correction, allowing each to excel at its specific function.
Data Source
Figure 1
Figure 2
Figure 3(a)~3(b)
AI summary
A port injection valve (16) injects fuel into an intake passage (12). A base injection amount (Qb) is an injection amount proportional to an amount of fresh air (η) introduced into a cylinder (20) of an internal combustion engine (10). A division process (S18 in Fig. 4) involves dividing the base injection amount (Qb) into a synchronous injection amount (Qs) and an asynchronous injection amount (Qns). In an intake-synchronous injection, the fuel is injected in synchronization with a period in which an intake valve (18) is open. In an intake-asynchronous injection, the fuel is injected at a time advanced with respect to the intake-synchronous injection. In a selective correction process (S20, S24), the asynchronous injection amount (Qns) is corrected according to a required correction amount (KAF, Dp, Dd, LAF, ΔQ) for the base injection amount (Qb), and the synchronous injection amount (Qs) is not corrected (Fig.4).