Self-Learning Fuel Injector Control for Cylinder Balance

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Solution Overview

Problem

Current fuel injector systems in vehicle engines face challenges in precisely predicting and controlling fuel delivery due to manufacturing variations, leading to inefficiencies and unbalanced combustion across cylinders, particularly in advanced engine cycles like HCCI, SI/HCCI, and Diesel engines.

Innovation Solution

A real-time self-learning system and method that uses an algorithm in the engine controller to correlate fuel mass and pulse width for each fuel injector, adapting to variations in temperature and fuel rail pressure, allowing for precise fuel injection control by learning and updating the characteristic curves of individual injectors during engine operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a typical characteristic curve for fuel injectors is used (established through laboratory testing), then the general fuel delivery performance can be predicted, but individual injector variations due to manufacturing tolerances cause imprecise fuel control and cylinder unbalancing

Engineering Contradiction:
Improveinjector performance consistencyVSAvoidfuel delivery prediction accuracy
Core Design Contradiction:
Manufacturing precisionVSMeasurement precision

Solution Approach 1:

The system performs preliminary identification of each injector's actual characteristic curve during initial engine operation or idle periods. This preliminary action captures individual injector variations before normal operation begins, allowing the controller to compensate for manufacturing tolerances from the start rather than using generic laboratory curves.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system continuously monitors actual fuel delivery through cylinder pressure sensors and air-fuel ratio measurements, comparing it against commanded injection quantities. This feedback loop allows the controller to detect deviations caused by individual injector variations and adjust pulse widths or injection timing to compensate, maintaining precise fuel control despite manufacturing tolerances.

Inventive Principle:
Principle #23Feedback

2Measurement precision

If individual injector characteristic curves are determined for each injector, then precise fuel control can be achieved, but the complexity of the system increases due to the need for real-time learning and adaptation

Engineering Contradiction:
Improvefuel delivery control precisionVSAvoidcontroller algorithm complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The controller performs self-learning by automatically identifying individual injector characteristic curves during normal engine operation without requiring external testing equipment or manual calibration. The system uses its own sensors and processing capabilities to adaptively determine each injector's performance, eliminating the need for complex external calibration systems while achieving precise fuel control.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system dynamically adapts injector characteristic curves based on changing operating conditions such as temperature, fuel rail pressure, and injector aging. Rather than using fixed static curves, the controller continuously updates injector parameters in real-time, allowing the system to maintain precision despite varying conditions while using a unified adaptive algorithm rather than multiple static lookup tables.

Inventive Principle:
Principle #15Dynamics

3Adaptability or versatility

If real-time learning of injector characteristics is implemented, then adaptive response to operating environment changes is achieved, but the learning process requires additional computational resources and processing time

Engineering Contradiction:
Improveresponse to operating conditionsVSAvoidlearning process time
Core Design Contradiction:
Adaptability or versatilityVSLoss of time

Solution Approach 1:

The system performs continuous learning and adaptation during normal engine operation rather than requiring separate calibration phases. The controller uses every combustion cycle to refine injector characteristics, accumulating data continuously as the engine runs. This approach converts idle computational capacity during routine operation into useful learning, achieving adaptability without dedicated calibration time.

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The system implements a two-stage learning approach where initial rapid learning occurs during idle or low-load conditions using simplified algorithms, followed by finer adjustments during normal operation. This partial action strategy allows the bulk of learning to occur when computational resources are abundant, reducing the processing burden during high-performance driving conditions while still achieving full adaptability.

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentUS8676476B2Method for real-time, self-learning identification of fuel injectors during engine operation
Publication Date: 2014.03.18 GM GLOBAL TECHNOLOGY OPERATIONS LLC
  • US8676476B2 patent drawing
  • US8676476B2 patent drawing
  • US8676476B2 patent drawing

AI summary

A system and method for real-time, self-learning characterization of fuel injector performance during engine operation. The system includes an algorithm for an engine controller which allows the controller to learn the correlation between the fuel mass and pulse width for each injector in the engine in real time while the engine is running. The controller progressively perceives those pulse widths that achieve the desired fuel mass, while it can continuously adapt what it has learned based on various input variations, such as temperature and fuel rail pressure. The controller then uses the learned actual performance of each injector to command the pulse width required to achieve the desired quantity of fuel for each cylinder on each cycle.