Rotor-Stator RF Fault Isolation Using VSWR and TDR
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Solution Overview
Problem
Current fault isolation systems in aircraft engines cannot accurately determine whether a detected anomaly is on the rotor or stator side, leading to unnecessary inspection and repair of components that are not the likely source of the fault.
Innovation Solution
A fault isolation sensor system that includes a rotor antenna and a stator antenna, with a radio frequency (RF) sensor generating measurement signals as the shaft rotates, and a controller using a voltage standing wave ratio circuit (VSWRC) and time domain reflectometer (TDR) to differentiate between rotor and stator side faults by analyzing signal ratios and propagation times.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If discrete sensors are installed on the rotating shaft to monitor properties, then measurement capability is improved, but fault isolation capability deteriorates because the system cannot determine which side (rotor or stator) is the fault source
Solution Approach 1:
The system divides the fault detection function into two independent antenna systems: a rotor antenna on the rotating shaft and a stator antenna on the stationary housing. By segmenting the sensing capability across these two distinct locations, the system can determine which side (rotor or stator) is the fault source based on which antenna detects the anomaly, thereby recovering the lost fault location information.
Solution Approach 2:
The patent introduces an intermediary signal transmission mechanism where measurement signals from the rotor-mounted sensor are transmitted wirelessly through the rotor antenna to the stator antenna. This intermediary transmission path allows the system to compare signal characteristics at different locations and identify the fault side, resolving the information loss about fault location.
2Productivity
If fault detection is performed without side identification, then detection speed is improved, but maintenance efficiency deteriorates due to unnecessary inspection and repair of non-fault components
Solution Approach 1:
By segmenting the antenna system into rotor and stator components with independent detection capabilities, the system可以快速 identify which side has the fault. This segmentation enables immediate direction of maintenance efforts to the correct side, preventing unnecessary inspection of the other side and thereby improving maintenance efficiency while preserving detection speed.
3Device complexity
If a single antenna system is used for measurement, then device complexity is reduced, but fault isolation capability is lost
Solution Approach 1:
The system uses segmentation of the antenna function into two simple, separate antenna systems rather than one complex antenna system. Each antenna is simple in design (rotor antenna on the shaft, stator antenna on the housing), but together they provide fault side identification capability. This approach maintains low device complexity while recovering fault isolation information.
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 system efficiently isolates faults to the correct side, reducing unnecessary inspections and repairs by providing accurate identification of fault locations, thereby improving maintenance efficiency and reducing downtime.
Implementation Method 1
the rotor antenna rotates with the shaft relative to the stator antenna, the stator antenna wirelessly connected to the rotor antenna across an air gap
Implementation Method 2
a controller using a voltage standing wave ratio circuit (VSWRC) to differentiate between rotor and stator side faults by analyzing signal ratios
Implementation Method 3
time domain reflectometer (TDR) to differentiate between rotor and stator side faults by analyzing signal propagation times
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
The present disclosure is generally related to a fault isolation sensor system for use with determining whether a potential fault is more likely to be on a rotor side or a stator side. The measurement signals are transmitted from the rotor antenna to the stator antenna, and then from the stator antenna to a controller. The controller is configured to monitor the measurement signals. If the measurement signal is outside of a predetermined range or past a predetermined threshold, then the stator antenna can be interrogated with an interrogation signal with a reflected signal being compared with the interrogation signal and a ratio thereof being used to identify the potential side of the fault.