1.Technical Features and Advantages

Fiber Bragg grating sensors have demonstrated significant technical advantages in the aerospace field. Firstly, its light weight and small size make it highly suitable for aircraft applications that are sensitive to weight. A single optical fiber can achieve multi-point measurement, significantly reducing the weight burden brought by traditional sensors. Secondly, it has outstanding anti-electromagnetic interference capability and is not affected by the strong electromagnetic environment on board, ensuring the reliability of data collection. Furthermore, it is made of quartz material and has excellent corrosion resistance, capable of adapting to extreme environments such as high altitudes, low temperatures, and strong radiation. In addition, its intrinsic safety feature ensures that it does not generate electric sparks, making it particularly suitable for monitoring hazardous areas such as fuel systems. These characteristics make FBG an ideal choice for aerospace monitoring.

2.Typical Application Scenarios

In the aspect of aircraft structural health monitoring, the fiber Bragg grating system plays a key role. The wing is a key monitoring area. By embedding the FBG sensor network in the composite material wing, the strain distribution and deformation under flight loads can be monitored in real time, providing data support for structural integrity assessment. Fatigue monitoring of the fuselage is equally important. Deploying FBG sensors in stress concentration areas can accurately capture the initiation and propagation of metal fatigue cracks. As a key load-bearing component, the landing gear also adopts FBG technology for its impact load monitoring, which assesses its service life by dynamically measuring the stress changes during landing.

Aero-engine monitoring is another important application field. Integrating FBG sensors on engine blades can monitor the vibration characteristics and temperature distribution in real time during operation, providing early warnings for preventing blade failure. The temperature monitoring of the hot-end components of the engine also adopts FBG technology. Its high-temperature resistance feature (up to 1000℃ with special packaging) meets the measurement requirements in extreme environments. Rotor dynamic balance monitoring utilizes the high-frequency response capability of FBG to accurately capture the vibration characteristics of the rotor.

In terms of flight control systems, FBG sensors are used for the precise measurement of key parameters. The position monitoring of the control surface adopts FBG displacement sensors to replace the traditional potentiometer sensors, improving reliability and accuracy. The pressure monitoring of the hydraulic system utilizes the pressure-sensitive characteristics of FBG to achieve passive measurement and avoid electromagnetic interference. In terms of fuel quantity monitoring, the FBG liquid level sensor achieves precise measurement by detecting changes in the refractive index of the medium.

3. Characteristics of Technical Implementation

The FBG system used in aerospace has special technical requirements. Sensor packaging needs to take into account the adaptability to extreme environments and be protected by using special alloys or ceramic materials. The installation process has strict requirements. There are both integrated solutions pre-embedded in composite materials and special treatment methods such as surface bonding. The data acquisition system needs to meet the requirements of high reliability and usually adopts redundant design and anti-radiation reinforcement measures. Signal processing algorithms need to have real-time performance and high precision, and be capable of extracting effective features from complex working conditions.

4. Application Cases and Development

New-generation passenger aircraft such as the Airbus A350 and Boeing 787 have adopted the FBG monitoring system for structural health monitoring. In the aerospace field, FBG is used for strain monitoring of launch vehicle bodies and temperature field measurement of satellite structures. NASA of the United States has applied FBG technology to the strain monitoring of the composite fuel tanks of the space shuttle, while the European Space Agency has deployed the FBG sensor network on the Ariane rocket.

The current development trends are mainly reflected in several aspects: Firstly, there is the development of miniaturization, with the size of sensors further reduced to meet the monitoring requirements of more precise components. Secondly, there is multi-functional integration. A single FBG sensor can simultaneously measure multiple physical quantities. The application of intelligent diagnostic algorithms is also deepening, and early warning of faults is achieved through machine learning. In addition, the development of wireless FBG sensor networks will simplify system wiring and enhance maintenance convenience.