Research On Morphology Perception And 3D Reconstruction Of Flexible Structure Based On Distributed Optical Fiber Sensor

Large flexible structures and space deployable structures are applied more and more widely in aerospace,such as large aspect ratio vehicles,solar panels,large deployable antennas and space manipulator.The intelligent identification of the service state of this kind of structure is of great significance to the design of new aircraft and the study of high altitude deep space exploration.Therefore,a real-time monitoring technology of structural deformation and vibration based on distributed optical fiber sensor is put forward in this paper,and real-time monitoring of aircraft structure deformation,vibration and impact is implemented to enhance the safety and reliability of aircraft during service.The main contents of this paper include the following aspects.Firstly,the strain sensing characteristics of fiber Bragg grating sensors are briefly introduced.The calibration,quantity calculation method and selection basis of FBG sensor are given.It provides an important guarantee for the subsequent construction of flexible structure oriented distributed optical fiber deformation,vibration and impact monitoring system.Secondly,In view of the requirement of the wing deformation monitoring of the variant aircraft structure,the numerical simulation and the morphological reconstruction algorithm of the flexible single side fixed support plate with similar wings are carried out.By means of MSC.Patran/Nastran finite element simulation,the overall strain distribution of flexible plate structure and the deformation characteristics under single point loading and multi-point loading are obtained by numerical simulation.Curvature computation and continuity method based on Fiber Bragg grating strain monitoring are studied.Based on that,a surface reconstruction algorithm based on orthogonal curvature information is presented.Thirdly,the deformation monitoring and inversion technique of flexible single side fixed support plate based on distributed optical fiber sensor.Based on the graphical software LabVIEW,the monitoring,inversion and visualization of static three-dimensional bending deformation,static torsion deformation and dynamic deformation are realized respectively.The results of laser displacement sensor and finite element simulation are used to verify and evaluate the effect of deformation reconstruction.Fourthly,in view of the requirement of on orbit deformation monitoring for deployable structures,a deformation monitoring and inversion algorithm for flexible deployable composite deployable structures based on curvature and arc length information curve reconstruction is studied.With the help of MSC.Patran/Nastran finite element analysis,the deformation characteristics of the free ends of the extended structure under two point symmetric loading and multi-point symmetrical loading are obtained by numerical simulation.A distributed optical fiber deformation monitoring and morphological inversion system is constructed,and the configuration and visualization of the extensional structure in different loading modes are realized.Finally,In view of the needs of on orbit vibration and shock monitoring for deployable structures,a fast identification method based on distributed optical fiber sensor for flexible service structure of deployable composite deployable structures is studied.With the help of the MSC.Patran/Nastran finite element analysis method,the displacement response law and the vibration modal characteristics of the extensional structure are obtained by numerical simulation.On this basis,a distributed optical fiber vibration and impact monitoring platform is built,and the first three natural modes and mode shapes of flexible and reel composite material extension structure are obtained.