Fuel Injector Reference Current Determination via Flux Profile Analysis
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Fuel injectors with solenoid drives experience variations in injection quantity due to electrical and mechanical tolerances, making precise actuation challenging, especially as injection times and quantities become smaller.
Innovation Solution
A method to determine a suitable reference current value by analyzing current and magnetic flux profiles through repeated actuations, varying the first predetermined current value, and comparing relationships during free-wheeling phases to synchronize the end of the opening process with the boost phase.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a fixed reference current value is used to end the boost phase, then the control method is simple, but the injection quantity varies due to temporal differences in opening behavior
Solution Approach 1:
The patent applies dynamics by making the reference current value variable rather than fixed. The system adapts the reference current value individually for each injector based on its temporal opening behavior characteristics, allowing the control parameter to change dynamically to match each injector's specific response profile, thereby achieving precise injection quantities despite manufacturing tolerances
Solution Approach 2:
The patent changes the parameter of reference current value from a fixed constant to a variable parameter that is determined individually for each injector. By measuring the temporal opening behavior and using this information to set injector-specific reference current values, the system compensates for manufacturing variations and achieves consistent injection quantities across all injectors
2Ease of operation
If the boost voltage is applied until a fixed current value is reached, then the control is simple, but the end of boost phase does not coincide with end of opening process
Solution Approach 1:
The patent implements feedback by measuring the temporal opening behavior of each injector and using this measurement information to determine an optimized reference current value. This feedback loop allows the system to adjust the boost phase duration and reference current value based on actual injector performance, ensuring that the end of the boost phase coincides with the end of the opening process for each individual injector
Solution Approach 2:
The patent applies preliminary action by determining the optimized reference current value in advance through measurement and analysis of the injector's opening behavior. This pre-determined reference current value is then used during normal operation to ensure proper synchronization without requiring complex real-time adjustments during the actual injection process
3Productivity
If shorter injection times are used to improve productivity, then the injection efficiency increases, but the relative differences in injection quantity become larger
Solution Approach 1:
The patent changes the reference current value parameter individually for each injector based on its measured temporal opening behavior. This individualization compensates for manufacturing tolerances that become more significant at shorter injection times, allowing each injector to achieve its target injection quantity accurately even when operating at high speeds with reduced injection duration
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 method allows for precise and balanced fuel injector actuation by ensuring the end of the boost phase coincides with the end of the opening process, improving injection control without additional hardware.
Implementation Method 1
Fuel injectors with a solenoid drive (also referred to as coil injection injectors)
Implementation Method 2
each current profile has a temporal progression of the current strength of a current flowing through the solenoid drive
Data Source
AI summary
A method for determining a reference current value for actuating a fuel injector, comprising a solenoid drive, for an internal combustion engine of a motor vehicle is described. The method comprises the following: (a) acquiring a multiplicity of current profiles with repeated actuation of the fuel injector, wherein each current profile has a temporal progression of the current strength of a current flowing through the solenoid drive, and wherein each actuation of the fuel injector comprises the following steps: (aa) applying a boost voltage to the solenoid drive of the fuel injector until the current strength of the current flowing through the solenoid drive reaches a first predetermined value, (ab) waiting for the current strength to reach a second predetermined value during a first free-wheeling phase, (ac) applying the boost voltage to the solenoid drive again until the current strength reaches the first predetermined value, and (ad) waiting for the current strength to reach the second predetermined value during a second free-wheeling phase, wherein the first predetermined value is varied for each actuation, the method also comprising (b) determining a multiplicity of magnetic flux profiles, wherein each magnetic flux profile corresponds to one of the multiplicity of acquired current profiles, and (c) selecting the reference current value on the basis of an analysis of the associated current profiles and magnetic flux profiles.