Research On Corrosive Environment And Angular Rotation Monitoring Of Aircraft Structure

With the rapid development of naval aviation,the advanced and complex degree of the equipment is constantly improving.The requirement for environmental adaptability is constantly improving too.At the same time,the requirements for authenticity and rationality of assessment on corrosive environment are also increasing.Therefore,a real-time monitoring node based on advanced sensor for corrosive environment was developed.By monitoring the corrosion parameters in aircraft structure service environment,a corrosion database can be established to guide corrosive environment assessment and aircraft anti-corrosion maintenance in later stage.In the field of aerospace and other harsh environments,traditional electronic sensors can be failed to meet the requirements of EMI,high reliability,high stability and light weight.Based on the diffraction principle of blazed grating,a Y-shaped self-collimating diffraction system was established.The system can be used to recognize small angle changes and bring further development to the study of angular displacement recognition.The main work includes the following aspects:Initially,the corrosion environment of the aircraft in service was analyzed and discussed.Temperature,humidity,time-of-wetness,chloride ion concentration and pH value were selected as monitoring parameters in corrosion environment of aircraft structure.The detection mechanism of each monitoring parameter was analyzed in detail.Based on that,an integrated temperature and humidity sensor and an interdigital electrode had been selected.The chloride ion concentration and pH sensor were studied and designed by ourselves.Furthermore,the corrosion monitoring node based on MSP430 was designed.It could measure the digital and analog signal of the sensor,collect and deal with the data,and store the data.At the same time,the node was powered by batteries.The node could run with low power consumption and realize the function of continuous environmental monitoring for a long time.According to hardware of the node,the software system of the node was designed.Also,a host computer software based on LabVIEW was designed to collect data uploaded by main control chip through serial port,and display data dynamically and store data to text files.Each function of the corrosion monitoring node was verified.It turned out that temperature and humidity sensor could work normally,and the time-of-wetness sensor could give expected response potential output.The chloride ion concentration sensor and pH sensor have good response potential output.Additionally,the basic principle of blazed gratings was introduced and simulated in two dimensions.The 3D diffraction spectrum graphics simulation of the blazed grating was carried out and characteristics of the diffraction spectrum related to the variation of the angular displacement of the blazed grating,that is,the diffraction angle,are extracted.A self-collimating optical transmission system based on Y-type optical fiber was built.It can realize self-collimating and collecting diffractive light.It can achieve the identification of rotation angle displacement of blazed grating by the peak wavelength shift of diffraction spectrum.The function verification was carried out on the optical platform,and angular displacement recognition can be realized.