Fuel Injector Pulse-Width Mapping Without Spoon Regions
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Solution Overview
Problem
Existing fuel injector control methods fail to account for pintle rebound, leading to 'spoons' in the fuel delivery plot, causing inconsistent fuel delivery and poor Injector Close Loop Compensation (ICLC) performance.
Innovation Solution
A modified fuel quantity versus pulse width plot is created by excluding spoon regions, ensuring monotonicity and optimizing control by avoiding these areas, using precise analysis of Hydraulic Opening (HO) measurements to determine optimal pulse widths.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a standard fuel quantity versus pulse width plot is used for injector control, then the control system can operate with a simple mapping, but pintle rebound causes spoon regions that lead to inconsistent fuel delivery and poor ICLC performance
Solution Approach 1:
The patent extracts and removes the harmful spoon regions from the fuel quantity versus pulse width plot. By identifying these regions where pintle rebound causes non-monotonic behavior and excluding them from the control map, the system eliminates the source of inconsistent fuel delivery while maintaining a relatively simple control structure.
Solution Approach 2:
The patent introduces dynamic compensation through ICLC (Injector Close Loop Compensation) that adapts the control plot based on actual injector behavior. The system dynamically adjusts the mapping between pulse width and fuel quantity by learning from actual performance and applying corrections, allowing the control system to adapt to variations and maintain reliability.
2Ease of operation
If ICLC trim is determined using a monotonic curve, then control is simplified, but the physical injector behavior with pintle rebound is not accurately represented, causing local errors
Solution Approach 1:
The patent changes the parameters used in the control plot by applying ICLC trim values that compensate for the discrepancies between the idealized monotonic curve and actual injector behavior. By adjusting pulse width or fuel quantity parameters based on learned corrections, the system maintains simple monotonic control while achieving accurate fuel delivery that accounts for physical pintle rebound effects.
3Reliability
If hydraulic optimization is used to minimize pintle rebound effects, then spoon regions are reduced, but part-to-part sensitivity increases and excessive force margin is required
Solution Approach 1:
The patent employs ICLC feedback mechanisms that measure actual fuel delivery and compare it with target values, then apply corrections to subsequent injections. This closed-loop approach compensates for pintle rebound and spoon regions without requiring hydraulic optimization, thereby avoiding increased part-to-part sensitivity and excessive force margins while maintaining reliable performance.
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
Improves ICLC performance by ensuring consistent fuel delivery and reducing part-to-part sensitivity, enhancing control accuracy and efficiency.
Implementation Method 1
electrical actuators (such as piezo or solenoid operated actuators) which are used to operate a needle valve
Implementation Method 2
against the biasing spring means
Data Source
Figure 1~2
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Figure 5~6
AI summary
A method of controlling a fuel injector, said injector including an electrically controlled actuator, said actuator adapted to control a needle valve by the movement of a needle to and from a valve seat of said needle valve, said method comprising : a) determining for said fuel injector, a plot of fuel quantity delivered (Q) by said fuel injector against the pulse width of an actuator actuation pulse sent to said actuator; b) providing a modified plot of fuel quantity delivered by said fuel injector against the pulse width of the actuator actuation pulse based on the plot of step a); c) using said modified plot to subsequently control activation of said fuel injector; wherein step b) comprising the steps of d) identifying spoons regions in said plot of step a), and e) reproducing the plot of step a) without any data from the spoon regions of the plot of a).