Fuel Injector Sensor Signal Error Recognition
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Solution Overview
Problem
Existing methods for recognizing errors in sensor signals for fuel injectors in internal combustion engines are inadequate, particularly in detecting shunts and increased contact resistance, which can lead to imprecise injection quantities and increased emissions.
Innovation Solution
A method that evaluates the signal level of the sensor signal in predefined time windows to recognize errors such as shunts and increased contact resistance, using recognition thresholds and additional physical variables to determine the resistance value of electrical shunts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional diagnostic methods are used to detect sensor signal errors, then simple errors like short-circuits can be detected, but shunts and increased contact resistance cannot be detected
Solution Approach 1:
The patent changes the diagnostic parameter from simple signal presence/absence to analyzing the temporal relationship between sensor signal edges and activation signal edges. By measuring time differences and comparing them against threshold values, the system can detect shunts and contact resistance issues that conventional methods miss, while maintaining compatibility with existing sensor systems.
Solution Approach 2:
The patent replaces conventional electrical diagnostic methods with a temporal-signal-based diagnostic approach. Instead of measuring electrical properties directly, it uses timing relationships between signals to infer electrical errors, enabling detection of shunts and contact resistance without additional electrical measurement hardware.
2Measurement precision
If additional sensors are used to detect characteristic operating points in fuel injectors with switch valves, then direct connection between electrical activation and injection timing is achieved, but system complexity increases
Solution Approach 1:
The patent makes the existing sensor serve multiple functions: it continues to detect characteristic operating points (injection timing) while simultaneously enabling diagnostic functionality for detecting electrical errors. The diagnostic method reuses the sensor signal without requiring additional sensors, thus achieving enhanced functionality without increasing hardware complexity.
Solution Approach 2:
The existing sensor system serves itself by providing diagnostic information through its normal operation. The sensor signal, already being used for injection timing detection, is additionally analyzed for timing deviations that indicate electrical errors, eliminating the need for separate diagnostic sensors or systems.
3Reliability
If sensor signal amplitude is used for error detection, then simple short-circuits can be identified, but shunts with non-negligible resistance cannot be detected
Solution Approach 1:
The patent transitions from static error detection (checking signal amplitude at fixed points) to dynamic error detection (analyzing temporal relationships between signal transitions). By examining how the sensor signal timing changes relative to the activation signal timing, the system can adaptively detect various error types including shunts with different resistance values, greatly expanding the detection range.
Data Source
AI summary
A method for recognizing an error in a sensor signal during operation of a fuel injector of an internal combustion engine. In the method, a switch valve of the fuel injector is activated with the aid of an activation signal, and the sensor signal is detected as a signal of a sensor, which is provided for the purpose of detecting characteristic operating points of the fuel injector, in a respectively predefined time window of the sensor signal, which includes a point in time of a characteristic operating point of the fuel injector. At least one property of the sensor signal is determined, which includes a signal level and/or a rise time. It is determined, based on the at least one property of the sensor signal, whether an error is present.