Closed-Loop Fuel Injection Calibration for Combustion Optimization

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Solution Overview

Problem

Conventional methods for calibrating fuel injection profiles in internal combustion engines are time-consuming and do not always achieve the thermodynamic optimum, as they rely on manual or statistical approaches that fail to efficiently identify the optimal fuel injection profile.

Innovation Solution

A closed-loop control method is employed to determine an optimized fuel injection profile by defining a setpoint combustion profile and using influential parameters such as cylinder pressure gradient, peak pressure, and start of combustion to iteratively adjust the fuel injection, minimizing deviations through multiple control loops and scaling factors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If manual or statistical test planning methods are used for fuel injection profile calibration, then the calibration process can be performed with simple equipment, but the calibration time is excessively long and the thermodynamic optimum cannot be reliably identified

Engineering Contradiction:
Improvecalibration speedVSAvoidcalibration time
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The patent implements a closed-loop control system where actual combustion parameters (cylinder pressure gradient alpha, peak pressure pMax, indicated mean effective pressure pmi, start of combustion SOC) are continuously measured and fed back to a controller. The controller compares actual values with setpoint values and automatically adjusts the fuel injection profile parameters (injection quantity, injection timing, injection pressure) to minimize deviations. This feedback mechanism enables rapid iterative optimization without manual intervention, dramatically reducing calibration time while achieving thermodynamic optimum.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent employs simulation models to predict combustion behavior and optimize fuel injection profiles before actual engine testing. The simulation environment allows virtual testing of multiple injection scenarios, identifying promising candidates for physical validation. This preliminary computational action reduces the number of required physical test cycles, thereby accelerating the overall calibration process while maintaining optimization quality.

Inventive Principle:
Principle #10Preliminary action

2Manufacturing precision

If manual calibration approaches are used, then the system complexity remains low, but the manufacturing precision of the fuel injection profile is insufficient to achieve thermodynamic optimum

Engineering Contradiction:
Improvefuel injection profile precisionVSAvoidcontrol system complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The closed-loop control system continuously measures actual combustion parameters (alpha, pMax, pmi, SOC) and compares them with target setpoints. Based on the deviations, the controller automatically adjusts fuel injection parameters with high precision. This feedback-driven approach achieves thermodynamic optimum by systematically optimizing multiple injection characteristics simultaneously, far surpassing the precision of manual calibration while accepting the necessary increase in control system complexity.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent implements a dynamic optimization process where the fuel injection profile is not fixed but continuously adapted based on real-time combustion feedback. The control system adjusts injection quantity, timing, and pressure dynamically across different operating conditions to maintain optimal combustion. This dynamic approach enables high manufacturing precision of the injection profile by responding to actual combustion behavior rather than relying on static pre-calibrated values.

Inventive Principle:
Principle #15Dynamics

3Ease of manufacture

If statistical test planning methods are used, then the calibration process is simpler to implement, but it is not always possible to find the optimum fuel injection profile due to the wide variety of combinations

Engineering Contradiction:
Improvecalibration process simplicityVSAvoidoptimization reliability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The closed-loop control system provides systematic optimization by continuously measuring combustion parameters and automatically adjusting injection settings based on feedback. This eliminates the randomness inherent in statistical test planning, ensuring that the true optimum is reliably identified through deterministic optimization algorithms. The feedback mechanism guides the search process efficiently through the parameter space, guaranteeing convergence to the optimal solution rather than relying on statistical sampling.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

Simulation models perform preliminary optimization calculations to identify promising injection profiles before physical testing. This computational pre-processing narrows down the search space and provides a reliable starting point for experimental validation, ensuring that the optimum is reliably found by combining virtual and physical optimization stages rather than relying solely on statistical testing.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentUS11441503B2Method for determining optimized fuel injection history
Publication Date: 2022.09.13 FEV EURO GMBH
  • US11441503B2 patent drawing
  • US11441503B2 patent drawing
  • US11441503B2 patent drawing

AI summary

In a method for determining an optimized fuel injection profile in an internal combustion engine, a setpoint combustion profile is firstly defined. Furthermore, at least one influential parameter which influences the setpoint combustion profile is determined. With the influential parameter, a corrected fuel injection profile is determined in a closed-loop control process. This method is preferably repeated iteratively.