The Design And Dynamic Analysis Of Capturing Mechanism Of Sampling Container For Extraterrestrial Bodies

With the final stage of the lunar exploration project and the mission planning of the future space development,the return of sampling container becomes the key point in deep space exploration task for China.The traditional method of sampling return is to use two large spacecraft for rendezvous and docking,then the sampling container can be transferred from a spacecraft to another by using the sealed channel.The sampling container is light and small,however,as for the two docking mechanism,their quality is large,their structure is complex,their control precision is high and their cost is great.Therefore,how to reduce the demand and weight of rendezvous and docking resources,simplify the operation of intersection and optimize the transfer task of sampling containers is the key to the research of sampling and return technology.According to the defect in cooperative target docking mechanism,a novel non cooperative target acquisition mechanism for sampling containers is designed and the corresponding research work has been carried out in this paper.The specific contents are as follows.Firstly,a set of extraterrestrial sampling container acquisition mechanism is designed to capture the sampling vessel in orbit.Each sub mechanism is designed in detail with the capture mechanism requirements for the capture envelope,structure weight,and performance.The three-dimensional geometric model was established and the function of each part is analyzed.Secondly,the expressions of the kinetic energy and potential energy of the system are obtained by determining the position vector of the deformed particle in the inertial coordinate system.Then the deformation displacement is discretized by the hypothetical mode method,and the dynamic equation of the system in the generalized coordinates is obtained.Then,the thermal simulation analysis and strength checking of the capture mechanism are carried out.The results show that the capture mechanism has less thermal deformation,and the strength and stiffness meet the design requirements.Finally,the dynamic simulation analysis of the mechanism is carried out in ADAMS.The simulation results of different working conditions show that the capture mechanism can capture the target successfully.All the parameters are in accordance with the design requirements.