The Dynamic Analysis On Probe-Cone Docking And Capture Process Of Micro-Satellite

Docking technology plays a key role in the operation and function enhancement of Micro-Satellite.The final purpose of the docking operation is the capture of the target satellite by the chasing satellite.Therefore,it is important to carry out the research on the docking capture dynamics.Considering the 6-DOF space movements of the chasing and the target satellites,the docking capture dynamic model in three-dimension is developed in this investigation.Aiming at the problem of probe-cone docking and capture of Micro-Satellite,the paper is organized as follows:First,according to the basic principle of the probe-cone docking mechanisms,the cushioning device,the inner wall of the receiving cone and the catching lock are designed in the paper.And the volume coordinate system is established based on the structural characteristics of each part.The three-dimension dynamic model of docking is established based on the Lagrange method.The dynamic model includes the whole process from the initial docking to the capture of collision,and the model obtains the generalized force matrix by virtual work principle.Secondly,a contact search algorithm for complex structures is proposed.In order to determine the contact point,this paper transforms the three-dimension search problem into two-dimension plane by using the rotating section method according to the characteristics of the contact point,the center of the docking ball and the rotation axis in the same plane.According to the geometric characteristics of the inner wall of the receiving cone,the method divided the cone into straight line zone,transition zone and capture zone.And the calculation method of the contact point inthese zones is proposed.Then,the direction and the magnitude of normal collision force are determined through using Hertz contact collision theory,and the magnitude and direction of tangential contact force are determined with the relative position and velocity of the contact point at the same time.Then,the simulated tests are conducted on the theoretical model.The finite element model is established by ABAQUS software.The modeling process includes the design and assembly of components,the definitions of materials,the constraints of definitions,the determination of connection elements,the division of mesh,the definition of contact,the definition of boundary conditions,etc.The contact force,the velocity of the center of mass,the stroke of the buffer device and the time course curves of the capturing distance are compared with the results obtained from the theoretical model.The results show that the curves of time history are in great agreement with each other,which fully proves the accuracy of the theoretical model.Finally,the factors of the docking system are analyzed.The influences of the initial relative velocity,the angle of the docking cone and the smoothness of the contact surface on the docking performance are mainly discussed.Moreover,the mechanism of the buffering device is analyzed.The effects of single factor and multi-factor are analyzed under certain conditions.Monte Carlo simulation analysis is introduced to determine the capture percentage under uncertain conditions.Based on these researches,an optimal method of buffering parameters is proposed.The work of this paper for the system of probe-cone docking of Micro-Satellite,which could provide some reference for the parameters design and optimization.