Glitch Detector for Fuel Injector Valve Timing
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Solution Overview
Problem
Existing glitch detection methods in fuel injector systems are inefficient due to energy addition from sampling windows, incorrect window positioning, and inability to distinguish between natural current decay and valve motion changes, leading to erratic valve timing and noise-induced errors.
Innovation Solution
A method that adjusts the sampling window position based on detected glitches, using second and third derivatives of the current profile to identify discontinuities and filter out noise, allowing for precise detection of valve movements without energy addition, and enabling real-time adaptation of injector firing characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a sampling window is used to detect current discontinuities for valve movement detection, then valve movement detection capability is improved, but energy is added to the system causing erratic valve timing
Solution Approach 1:
The patent extracts only the essential detection function by using a narrow sampling window that captures current discontinuities without applying voltage to the actuator. This separates the detection function from the actuation function, allowing glitch detection without energy addition that would cause erratic valve timing.
Solution Approach 2:
The patent introduces an intermediary sampling circuit that monitors current discontinuities without directly energizing the actuator. This intermediary detection mechanism allows valve movement detection while preventing the sampling process itself from influencing valve timing through energy addition.
2Measurement precision
If the sampling window position is fixed, then device complexity is reduced, but detection accuracy decreases due to inability to track valve movement changes
Solution Approach 1:
The patent implements a dynamic sampling window position that automatically adjusts based on detected glitch patterns. The sampling window transitions from a fixed position to a movable position that tracks valve movement characteristics, improving detection accuracy while using simple feedback control rather than complex positioning mechanisms.
Solution Approach 2:
The patent uses feedback from detected current discontinuities to adjust the sampling window position. The system monitors glitch occurrences and automatically repositions the sampling window to optimize detection, creating a self-adjusting mechanism that improves accuracy without requiring complex external control.
3Measurement precision
If standard glitch detection methods are used, then detection capability is provided, but noise-induced errors occur and natural current decay cannot be distinguished from valve motion changes
Solution Approach 1:
The patent applies preliminary filtering and analysis to the sampled current data before making detection decisions. By pre-processing the current signals and establishing baseline characteristics of natural decay, the system prepares detection criteria that distinguish genuine valve motion glitches from noise and normal current variations.
Solution Approach 2:
The patent changes detection parameters dynamically based on operating conditions. The sampling window position, duration, and threshold levels are adjusted according to detected patterns, allowing the system to adapt to different noise levels and valve movement characteristics, thereby improving reliability across varying operating conditions.
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 approach minimizes energy input, improves detection accuracy, and allows for real-time correction of valve timing changes, enhancing the precision and reliability of fuel injection systems by accurately tracking valve movement characteristics without external sensors.
Implementation Method 1
the valve comprising an electromagnetic actuator which is arranged to move the valve between first and second positions during a valve cycle
Implementation Method 2
sensing means for sensing a current through the actuator, a processor arranged to analyse the received data for current discontinuities
Data Source
Figure 1~2
Figure 3A~3C
Figure 4~5
AI summary
A glitch detector (6) for detecting valve movement of a valve in a fuel injector of an engine system, the valve comprising an electromagnetic actuator (4) arranged to move the valve between first and second valve positions during a valve cycle, the engine system comprising sensing means (10) for sensing a current through the actuator. The detector comprises control means (30) arranged to control the sensing means; inputs for receiving from the sensing means data related to the current through the actuator (4); a processor (28) arranged to analyse the received data for current discontinuities; and outputs for outputting a valve movement signal in dependence upon the current discontinuities determined by the processor. The control means is arranged to enable the sensing means during a finite sampling window (80) and to (i) move the sampling window from a first window position for a first injection event to a progressively later window position for one or more subsequent injection events; (ii) to calculate a new sampling window position on the basis of a valve movement signal output for at least two of the preceding window positions; and (iii) to feedback the new sampling window position for a subsequent injection event.