Study On Modular Flexible Capturing And Docking Mechanism

Compared with the allogeneic isomorphic docking mechanism,the rod-cone docking mechanism has a small envelope range and light weight,and is widely used in space docking.With the development of on-orbit maintenance and service technology,the spacecraft raises certain requirements in the docking process such as impact sensitivity and low disturbance.The traditional rigid rod-cone docking mechanism has certain limitations result from docking and correcting attitude directly.A flexible probe-cone docking scheme using a claw-type capturing lock and a spring as flexible probe is proposed.This solution uses a flexible probe instead of the rigid rod for docking.The probe adaptively bends into the docking cone during the capturing process to achieve low impact and correct attitude softly.At the same time,the docking mechanism adopts the peripheral modular arrangement,which proposes a solution for the problem of the probe's vibration during docking process of large spacecrafts,and optimizes the layout scheme of the flexible docking module.Considering the berthing condition with mechanical arm assists,the kinematic model of the flexible capturing and docking mechanism is established by D-H coordinate transformation method,and the contact force model of the guiding head and the docking cone in the capturing process is established by using the Hertz contact force theory.The equivalent beam model and dynamic model of the spring are established by energy equivalence theory and absolute nodal coordinate method.The rigid-flexible coupled dynamics model of the capturing process is established by Lagrange multiplier method,and these models are verified by ABAQUS/Explicit Dynamic simulation.Modeling and analyzing the range that can reliably capture at a given initial deviation for single-module docking.By changing the parameters of the docking mechanism in the established dynamic model and doing numerical simulation,the contact form in the capturing process is studied,and then the coupling relationship between the contact force and each parameter is analyzed and the parameter selection method of low contact force capture is given.In addition,for the multi-module docking conditions,the criteria for its capture feasibility and the method for analyzing the mechanical arm during capturing are proposed.A set of single-module prototypes and a test platform for the flexible docking mechanism were developed,and the docking function test,separation performance test,axial tensile stiffness test of the docking mechanism were carried out.The test results showed that all aspects of the developed docking mechanism performance meets the design requirements and verify the correctness of the proposed flexible docking scheme and the established theoretical analysis model.