Contact Detumbling Of Tumling Large Space Debris Capture

With exploring of space,plenty of space debris have occupied the Geostationary Orbit.These debris pose a major threat to on orbit equipment.In response to this threat,the Active Space Debris Removal Technology(ADR)of space debris emerged at the right moment.In particular,ADR for large-scale space debris has great significance for controlling the number of space debris.However,the movement of a large-scale space debris is complex,which is difficult to directly capture and remove.In order to increase the capture success rate of large space debris,a detumble module is added to an active removal system,which can reduce the impact to the active removal system during the removal process.Firstly,this paper focuses on the research of detumble process.In this paper the detumble mechanism for large-scale space debris is connected between a capture mechanism and a robot arm.The target to detumble is a special satellite.The motion characteristics of the target are analyzed.According to the distribution of its kinematic energy,the motion of target can be classified into single-axis motion and three-axis motion.Then the detumble momentum is analyzed,in this paper the momentum is applied by friction,the dimension of momentum is roughly confirmed.To correspond to the motion of target,single-axis detumble and three-axis detumble are analyzed,the dynamic functions of the detumbling process are constructed,basing on the equation of three-axis detumble,decomposition of the detumble momentum is analyzed.Secondly,according to technical requirements design of detumble mechanism is finished.The detumble mechanism is consisted of three dissipators,the dissipator can consume energy of target with a friction pair,the stress of the friction pair is analyzed,the components which can influent the stress are found.After the dissipator is designed,according to the decomposition of the detumble momentum,the special position relationship among dissipators can be roughly determined,the spatial parameters are precisely determined according to the motion space of detumble mechanism,in what the detumble mechanism can keep safety during motion.When the position of dissipators are determined,the connecters are designed.The connectors can keep position and provide structure support.The primary parts are checked for stress.Then the dynamics model of triaxial detumble is set up,the feedback force is analyzed.According to the detumble mechanism,building a simulation platform in Adams the model simulates detumbling process,in the process the target is at different initial angular velocities and forces.The relationship between the force distribution of the detumble mechanism and the initial angular velocity and the feedback force on the pedestal is analyzed.The RBF neural network is used to fit this relationship.The neural network is used to determine the initial force and to ensure that the detumble mechanism can maintain a certain range of feedback force for a type of target with different initial angular velocity.Finally,according to the three-axis detumble mechanism,a ground uniaxial experimental platform is set up.In the ground experiment,the dynamic and static friction relations of the friction pair is tested,and the uniaxial detumble experiment was performed.The relationship between the force and friction torque of the friction pair is simulated.Coupling,and use the experimental data of uniaxial detumble to correct the triaxial detumbling simulation.Applying the detumble momentum simultaneously on the three axes of the target centroid coordinate system,what can eliminate the target residual kinematic energy.For large space debris,adding a detumble mechanism to the active removal system can reduce the feedback force in the capture process and increase the active shift the target angular kinetic energy range.