多充液可机动柔性航天器模块化建模和耦合动力学分析

Modular modeling and coupled dynamical study for liquid-filling spacecraft with multiple maneuverable flexible appendages

针对现代航天器因携带多类型充液贮箱及可机动柔性附件而导致的动力学建模困难,文中基于参数辨识理论和有限元方法实现了该类复杂航天器的模块化建模。首先,考虑航天器运行时贮箱内液体的小幅晃动问题,利用球形贮箱小幅晃动的参数化模型推导出球形充液贮箱小幅晃动的动力学方程;其次,根据薄板小幅振动理论,运用有限单元法建立柔性附件四边形板单元动力学模型,将附件相对航天器变化的姿态角代入坐标转换矩阵,构造柔性附件作大范围机动时的时变坐标转换矩阵。再次,基于凯恩方程推导航天器整体系统的动力学状态方程,利用MATLAB软件编制出相应的模块化建模程序。最后,通过数值算例分析,研究典型构型航天器中柔性附件以不同方式机动的系统整体耦合动力学性能,验证了该建模方法的通用性、适用性和准确性。

This paper focuses on the problem of dynamic modeling for modern spacecraft with multi-type liquid-filling tanks and maneuverable flexible appendages.Based on parameter identification theory and finite element method,the dynamic modeling for complex spacecraft is deduced.Firstly,in view of small disturbance during spacecraft operation,the dynamic equations of small-amplitude liquid sloshing in spherical tank are derived by using the parametric model for liquid sloshing.Secondly,based on the theory for small deformation of plate,the dynamic quadrilateral plate element model of flexible appendage is established using finite element method.The time-varying coordinate transformation matrix of flexible appendage relative to spacecraft is constructed by substituting the attitude angle of the appendage into the transformation matrix.Then,the dynamic state equations of the spacecraft system are derived based on Kane's equation,and the corresponding modular modeling program is compiled by MATLAB software.Finally,through numerical example analysis,the coupling dynamic performance of the typical configuration spacecraft with flexible appendages maneuvering in different ways is studied,and the universality,availability and accuracy of the modeling method are confirmed.