Fiber-grating-vibration-sensing-system-based mass unbalance detection method of helicopter blade

Abstract

The invention provides a fiber-grating-vibration-sensing-system-based mass unbalance detection method of a helicopter blade. Fiber grating sensors are arranged on a blade surface (1) and a blade pedestal surface (2) of a helicopter and are connected to a demodulation instrument and upper computer at the rear side by a fiber slip ring and an optical cable. When the blade rotates, the strain of the blade surface and vibration of the blade pedestal are sensed (3)and data are connected (4); a rear data processing system carries out a time domain analysis (5) and a frequency domain analysis (6) to extract data features; and the extracted data are compared with the normal blade data to determine whether the mass of the helicopter blade is unbalanced and the unbalanced degree (7). According to the invention, defects that time and effort are wasted and certain danger is caused when the manual paper roller type benchmarking method and the result is not objective due to human eye dependence and the calibration time is long when the stroboscopic lamp targeting method is used can be overcome; and the detection and quantitative analysis can be carried out on the mass unbalance of the helicopter blade objectively and precisely.

Description

technical field [0001] The invention belongs to the field of structural health monitoring, in particular to a method for detecting the mass imbalance of a helicopter blade based on a fiber grating vibration sensing system. Background technique [0002] Helicopter rotor, as the core component that provides lift and control force for helicopter flight, is directly related to the safety of helicopter and the pros and cons of other important performances. The cone produced by the high-speed rotation of the helicopter rotor is a comprehensive reflection of the technical state of the helicopter rotor system, including changes in the quality of the blades, blade installation and fixing, etc., which are reflected in the changes in the cones of the rotor. Among them, the mass imbalance of the blades will cause the vibration of the aircraft fuselage, which will affect the flight safety. problem is detected. [0003] There are two traditional methods for measuring blade mass imbalanc...

AI Technical Summary

Problems solved by technology

Compared with the artificial paper tube target method, this method has made some progress, but it still has disadvantages: 1. It cannot record data, relies on human judgment, and is not objective enough and cannot perform quantitative analysis; 2. It takes a long time to lock the target for the first time, and it may Helicopter body structure poses a hazard

At present, there are no examples and patents of applying fiber grating sensors to the unbalance detection of helicopter blades, but the advantages of fiber grating sensors make them have good application prospects, and the invention content of this patent is also rich. Practical

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