Research On Configuration Design And Dynamic Characteristics Of Deformable Spacecraft

With the improvement of aerospace technology in various countries in the world,the production of satellites has been mass-produced and the cost has been greatly reduced,which has led to a sharp increase in the number of satellites launched by various countries,resulting in an increase in the number of failed satellites and space debris in space.On the one hand,it is very likely that the failed satellites and space debris in space will collide with other spacecraft in orbit.The space debris generated after the collision will become new space junk,which will increase the pollution to the space environment.On the other hand,due to the limited orbital resources in space,if these failed satellites and space debris occupy the orbits,it will lead to a reduction in the resources of the entire space environment,which will greatly hinder other countries from exploring space.Therefore,it is of vital value and significance to vigorously carry out research on on-orbit service technology.In this paper,aiming at the on-orbit capture of micro-nano satellites and space debris,the conceptual design of a deformable spacecraft is carried out,and a foldable deformable spacecraft configuration is proposed.The overall closed-chain space mechanism is used as the main structure of the deformable spacecraft.Features of deformation and high mobility.In addition,the overall mechanism has six meshes.When capturing a target,the internal space formed by the six meshes can be used to capture targets of different shapes and sizes.All six meshes can capture targets,realizing omnidirectional capture.The specific research contents are as follows:(1)The configuration design of deformable spacecraft is carried out,and the overall closed-chain space mechanism is determined as the main structure of the deformable spacecraft,and the capture strategy of the mechanism is given.After that,the degree of freedom analysis of the mechanism is carried out,and it is concluded that the mechanism has 7 degrees of freedom.The inverse solution of the mechanism and the position coordinates of each joint are obtained through kinematic analysis.The capture tolerance analysis of the deformable spacecraft is carried out,and the envelope size in the presence of both positional and attitude deviations is given.Then,a secondary folding design is carried out for the deformable spacecraft;(2)The Lagrange method is used to analyze the deformation of a single vertex of the deformable spacecraft,and the torque change curve is obtained,which is compared with the torque change curve obtained by simulation to verify the correctness of the theoretical analysis.Afterwards,the working mode,deformation mode and the process of capturing the target of the deformable spacecraft are simulated to verify the rationality of the configuration and provide input parameters for the subsequent ground principle prototype test.(3)The mechanical properties of the deformable spacecraft are analyzed,including the static analysis of the rods,modal analysis,harmonic response analysis and random vibration response analysis,and the strength and stiffness properties of the deformable spacecraft under the excitation of the external environment are obtained,which verifies the feasibility of the structure of the deformable spacecraft.(4)The ground principle prototype of the deformable spacecraft is developed.After that,the test platform is built,and the vertex deformation tests and target capture tests of the prototype are carried out.The folding,deformation and capture functions of the prototype are tested through the tests to verify the feasibility of the concept of the deformable spacecraft designed in this paper.There are 117 pictures,13 tables and 69 references in this paper.