Research On Identification And Repair Of The Motion Function Reliability Defects For A Space Docking Mechanism

Docking mechanism is an important device of the space station.It is of great significance to improve reliability of the docking mechanism for ensuring docking and completing space missions.The kinematic accuracy reliability model and the action reliability model considering jam of a new type of ring docking mechanism（hereinafter referred to as "docking mechanism"）are established,and the defects in the motion function reliability of the docking mechanism are identified by sensitivity analysis and its motion function reliability is improved by using particle swarm optimization to repair the defects.The main failure modes of the docking mechanism and their corresponding influencing factors are analyzed.The kinematic accuracy model of the gear mechanism is established baesd on the energy mehtod with the time-varying meshing stiffnesss of the gear mechanism as the main error excitation.The kinematic error of the gear mechanism under the maximum ambient temperature corresponding to different modification coefficients is obtained through finite element analysis,and the limit state function of the kinematic error of the gear mechanism is obtained by using BoxBehnken design and response surface method fitting;the kinematic accuracy model of the single cam curved groove mechanism is obtained by combining the effects of load deformation,wear,hinge clearance and manufacturing errors of the parts,and the kinematic accuracy reliability model of the docking mechanism is obtained by coupling the kinematic error of the gear mechanism and single cam curved groove mechanism.The dynamics of the docking mechanism is analyzed and the forces under different stages of the docking process are obtained by Adams simulation.The lubrication state of the docking mechanism under different working conditions is obtained by analyzing the effect of the temperature on the oil film thickness,and the action reliability of the docking mechanism is evaluated by comparing the magnitude of the driving torque and resistance torque considering self-locking and the lack of the driving torque.The defects in the kinematic function reliability of the docking mechanism are identificated by Monte Carlo simulation and Sobol sensitivity analysis,and the gear mechanism and cam curved groove mechanism of the docking mechanism are optimized by using particle swarm optimization to reduce the kinematic error under the influence of the sapce heat radiation and avoid the motion jam.The defects in the motion function reliability of the docking mechanism are repaired.