Accuracy Evaluation Method for Blade Vibration Measurement in Blade Tip Timing Based on Direct Calibration Using Time...

Area of Science:

• Mechanical Engineering
• Condition Monitoring
• Instrumentation and Measurement

Background:

• Non-contact blade vibration measurement (BTT) is crucial for rotating machinery health monitoring.
• Time of Arrival (ToA) data in BTT directly impacts vibration analysis accuracy.
• Current BTT error assessment lacks direct calibration for ToA, leading to imprecise evaluations.

Purpose of the Study:

• To develop a direct calibration method for ToA to evaluate BTT measurement accuracy.
• To create a dedicated device for assessing BTT accuracy and stability.
• To validate the proposed method and device using an optical fiber BTT system.

Main Methods:

• Developed a ToA direct calibration model transforming ToA variations into angular differences.
• Systematically analyzed associated errors for BTT accuracy assessment.
• Employed the Monte Carlo method for device uncertainty evaluation, considering systematic and random factors.

Main Results:

• The developed device at 0.5° and 1000 rpm yielded ToA with standard uncertainty of 8.824 × 10⁻³ μs.
• Validated optical fiber BTT system achieved relative accuracy <0.8% and repeatability accuracy >0.5%.
• Demonstrated the effectiveness of the direct calibration method and device for BTT systems.

Conclusions:

• The proposed method offers a reliable and precise approach for evaluating BTT measurement accuracy.
• Direct ToA calibration enhances the effectiveness of real-time condition monitoring and fault detection.
• The developed device provides a validated tool for assessing BTT system performance.