Blade Health Monitoring via Deflection Normalization
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Solution Overview
Problem
Existing systems fail to accurately predict cracks or fractures in rotor blades or airfoils in real time, leading to potential hazards and significant monetary losses due to the inability to differentiate between defects and operational variations.
Innovation Solution
A method that uses sensors to measure the time of arrival (TOA) of blades at a reference point, processing subsystems to determine static and dynamic deflection by accounting for operational data and reseating effects, and normalization techniques to accurately assess blade health.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional vibration monitoring systems are used to detect blade defects, then they can identify potential issues, but they produce false positives by unable to differentiate between operational variations and actual defects
Solution Approach 1:
The system transforms raw vibration data into a different parameter domain by calculating blade deflection through double integration of acceleration signals. This parameter transformation (from acceleration to deflection) enables differentiation between operational variations and actual defects, resolving the contradiction between detection sensitivity and false positive rate
Solution Approach 2:
The patent replaces traditional mechanical vibration analysis with a signal processing approach that uses numerical integration to convert acceleration measurements into deflection profiles. This substitution of mechanical interpretation with mathematical transformation enables more accurate defect identification by eliminating false positives from operational variations
2Reliability
If real-time monitoring is implemented to predict cracks and fractures, then safety and maintenance efficiency improve, but system complexity and cost increase
Solution Approach 1:
The system introduces a processing subsystem as an intermediary between the simple TOA sensor and the health prediction outcome. This intermediary performs signal processing (integration and normalization) to translate raw timing data into meaningful deflection measurements, enabling real-time safety prediction without requiring complex sensor arrays or measurement systems
Solution Approach 2:
The patent creates a virtual model of blade behavior by calculating expected TOA based on operational conditions and comparing it with actual measurements. This copying approach (creating a reference model for comparison) enables real-time health assessment using simple timing measurements rather than complex direct monitoring of blade stress or crack propagation
3Measurement precision
If operational data is collected and processed to normalize blade deflection, then accurate health assessment is achieved, but data processing time and computational requirements increase
Solution Approach 1:
The system performs preliminary normalization of blade deflection data by accounting for operational conditions (speed, load, temperature) in real-time. By pre-establishing the relationship between operational parameters and expected deflection variations, the system can quickly normalize new measurements without extensive computational analysis, reducing processing time while maintaining accuracy
Data Source
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AI summary
A method for monitoring the health of one or more blades (12) is presented. The method includes steps of determining (106) a delta TOA corresponding to each of the one or more blades (12) based upon respective actual time of arrival (TOA) of the one or more blades (12), determining (320) a normalized delta TOA corresponding to each of the one or more blades (12) by removing effects of one or more operational data from the delta TOA, and determining (330) a corrected delta TOA corresponding to each of the one or more blades by removing effects of reseating of the one or more blades from the normalized delta TOA.