Fuel Injection Timing Adjustment for Cylinder Air-Fuel Maldistribution
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Fuel injection systems face challenges in maintaining consistent fuel pressure in the fuel rail, leading to cylinder-to-cylinder air-fuel ratio maldistribution and increased engine emissions due to pressure changes during engine cycles.
Innovation Solution
Monitoring and sampling fuel rail pressure at high speeds while fuel injectors are open to generate compensation factors, adjusting subsequent fuel injection timings, and evaluating fuel injector degradation to optimize fuel injection amounts and timing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If fuel is injected based on expected pressure without real-time monitoring, then the fuel injection system is simple and fast, but cylinder to cylinder air-fuel ratio maldistribution occurs and emissions increase
Solution Approach 1:
The system implements feedback by monitoring fuel rail pressure in real-time during fuel injection events and using this information to generate compensation factors that adjust subsequent fuel injection timing. This closed-loop approach ensures accurate fuel delivery despite pressure variations, eliminating air-fuel ratio maldistribution without requiring complex hardware modifications.
2Manufacturing precision
If fuel rail pressure is monitored at high speed during injector open period, then air-fuel ratio control precision improves, but measurement and processing complexity increases
Solution Approach 1:
The system performs preliminary action by sampling fuel rail pressure specifically during the injector open period, when the pressure change is most informative for determining compensation factors. This targeted sampling approach captures the critical pressure data needed for precise air-fuel ratio control while minimizing unnecessary measurements, thereby reducing processing complexity.
3Stability of the object's composition
If compensation factors are generated from pressure sampling to adjust injection timing, then cylinder to cylinder fuel maldistribution is reduced, but processing time and computational load increase
Solution Approach 1:
The system applies periodic action by generating compensation factors on a cycle-by-cycle basis, updating fuel injection timing adjustments periodically with each engine cycle. This approach maintains stable air-fuel ratio composition across cylinders while managing computational load through regular, predictable processing intervals rather than continuous calculation.
4Object-generated harmful factors
If fuel injection timing is adjusted using compensation factors, then emissions decrease, but control system complexity increases
Solution Approach 1:
The system implements parameter changes by adjusting fuel injection timing based on compensation factors derived from pressure sampling. This modifies the injection timing parameter dynamically to optimize combustion and reduce emissions. The approach achieves emission reduction through software-based parameter adjustment rather than hardware changes, minimizing control system complexity.
Data Source
AI summary
Methods and systems for adjusting timing of fuel injectors to reduce cylinder to cylinder air-fuel maldistribution are disclosed. In one example, fuel injection timing is adjusted as a function of pressure ratios that are based on fuel rail pressures observed during injection of fuel. The pressure ratio may be a ratio of a root-mean-square pressure and a scheduling fuel pressure.