空间桁架横梁分布式光纤变形监测与误差修正

Distributed Optical Fiber Deformation Monitoring and Error Correction for Space Truss Beams

空间桁架结构是一种具有低频、密模、非线性等复杂动力学特征的大型挠性空间结构,针对此类结构服役状态的智能辨识对于目前开展高轨深空探测研究具有重要意义。为此,该文提出了一种基于分布式光纤光栅传感技术的空间桁架横梁结构变形监测与反演方法。借助ANASYS有限元分析法,数值模拟得到横梁结构在不同载荷作用下的应变、位移分布特征,研究了基于位移算法的桁架横梁结构变形反演算法,计算得到空间桁架结构不同位置的挠度信息。在此基础上,构建了单边固支桁架横梁分布式光纤变形监测与反演系统,平均相对误差约为2.4%。最后,提出了一种用于横梁结构变形反演精度提升的误差分离修正方法,修正后平均相对误差下降了41.7%。研究结果表明,该文所提方法具有精度高,实时性好等优点,能为及时准确获取空间桁架结构展开形态,实现桁架形态自适应调节与主动控制提供有力保障。

The space truss structure is a large flexible space structure with complex dynamic characteristics such as low frequency,dense mode and non-linearity.The intelligent identification of the service state of such structure is of great significance for deep space exploration of high orbit.For this reason,a method of deformation monitoring and inversion of space truss beam structure based on distributed fiber Bragg grating sensing technology is proposed in this paper.With the help of ANASYS finite element analysis method,the strain and displacement distribution characteristics of the beam structure under different loads are obtained by numerical simulation.The inversion algorithm of the deformation of truss beam structure is studied based on displacement algorithm,and the deflection information of space truss structure at different positions is obtained by calculation.On this basis,a distributed optical fiber deformation monitoring and inversion system for unilateral fixed-supported truss beams is constructed.The average relative error is about 2.4%.Finally,an error separation correction method for improving the inversion accuracy of beam structure deformation is proposed.After correction,the average relative error is reduced by 41.7%.The research results show that the proposed method has the advantages of high precision and good real-time performance.It can provide timely and accurate access to the structure of the space truss structure,and realize a powerful guarantee for adaptive adjustment and active control of the truss shape.