Frequency Sensor Fault Detection Using Inverted Signal Segmentation
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Solution Overview
Problem
Current methods for detecting faults in frequency sensors, particularly in aeroengine control devices, are inadequate as they cannot reliably identify short circuits to ground, leading to costly and unreliable component replacements.
Innovation Solution
A method involving injecting pulses into the terminals of a frequency sensor, with a digital computer analyzing the output signals to differentiate between types of faults, including short circuits to ground, using alternating signals of varying amplitudes to determine fault types based on signal frequency responses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If complex electronic components are used to detect and identify sensor faults, then fault identification capability is improved, but device complexity and cost increase
Solution Approach 1:
The fault detection method segments the fault identification process into distinct test phases: open circuit detection, differential short circuit detection, and ground short circuit detection. Each phase uses a specific signal injection pattern and evaluation criterion, allowing comprehensive fault identification without requiring complex electronic components. The segmentation of detection functions into discrete, manageable steps resolves the contradiction by achieving high measurement precision through procedural complexity rather than hardware complexity.
2Measurement precision
If complex electronic components are used to detect and identify sensor faults, then fault identification capability is improved, but cost increases
Solution Approach 1:
The detection method is segmented into sequential test phases that can be implemented using existing simple electronic components already present in the sensor system. By dividing the fault identification into distinct phases (open circuit test, differential short test, ground short test), the invention achieves comprehensive fault detection capability without requiring additional complex or expensive hardware, thus resolving the cost contradiction.
Solution Approach 2:
The sensor system performs self-diagnosis by using its own existing components (the sensor element, power supply, and basic circuitry) to detect and identify faults. The method leverages the sensor's inherent properties and existing structure to conduct multiple types of fault detection, eliminating the need for external complex diagnostic equipment and reducing overall system cost while maintaining high fault identification capability.
3Device complexity
If simple detection methods are used, then device complexity is reduced, but fault identification capability deteriorates
Solution Approach 1:
The invention applies preliminary actions by injecting specific test signals into the sensor before actual operation to proactively detect and identify faults. The method performs preliminary tests including open circuit detection, differential short detection, and ground short detection by injecting calibrated signals and measuring responses. This preliminary action approach enables comprehensive fault identification using simple detection hardware, resolving the contradiction between simplicity and capability.
Solution Approach 2:
The fault detection method employs periodic action by sequentially executing different test phases at predetermined intervals or before operation. The system periodically injects test signals, measures responses, and evaluates fault conditions in a structured sequence. This periodic execution of simple test routines achieves comprehensive fault identification capability without requiring continuously complex monitoring systems, thus resolving the contradiction between simplicity and detection capability.
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 allows for simple and reliable detection and identification of faults, reducing unnecessary component replacements and improving system reliability by distinguishing between open circuits, differential short circuits, and short circuits to ground.
Implementation Method 1
the frequency sensor generally including a coil that presents inductance so that it responds to the pulse by returning a strong pulse in the output signal
Data Source
AI summary
A method of detecting a fault of a frequency sensor having a bias resistor and associated with a rotary member. The following steps are performed while the rotary member is stationary: injecting into the bias resistor of the sensor inverted alternating signals (S1, S2) comprising at least one first alternation (A1) and at least one second alternation (A2), the first alternation being of amplitude greater than the amplitude of the second alternation; and detecting a frequency of an output signal (S″) from the sensor. A measurement circuit implementing the method is also provided.