The Design And Dynamics Analysis Of The Orbital Replacement Unit Assembly

With human continuous development of space exploration， the number ofspacecraft performing various tasks is becoming larger and larger. The technology ofspacecraft on-orbit servicing becomes particularly important, spacecraft has problems,such as, energy shortage, technology lagging behind, software and hardware failure,may lead to be scrap by the loss of satellite. So designing of spacecraft orbitalreplacement unit based on on-orbit servicing was proposed，on-orbit replacing andupgrading module, supplying consumables, can extend the servicing life of spacecraftand keep the task sustainability. This paper designs an orbital replacement unit, and doessome statics and dynamics analysis to verify the rationality of the design.This paper starts from mission requirements and design principles, have a designscheme of orbital replacement unit, the structure design includes the structure shelldesign, the quasi cone-pin positioning device design, the locking device based on quasirectangular screw blade design; The locking device uses the Ultrasonic Motor withself-locking when power is off, successfully solved the problem of the locking looseswhen power is off, and have the advantages of simple structure and light quality; andstudy the cold welding protection of orbital replacement unit.In the process of injecting into orbit with the spacecraft, the orbital replacementunit will suffer the impact of overweight and strong vibration load, In this paper,mechanics performance of orbital replacement will be analyzed unit by the finiteelement software ANSYS Workbench. to check strength whether meet the requirements,by analyzing the static overload for the whole orbital replacement unit; getting theinherent frequency by conducting the whole orbital replacement unit and the orbitalreplacement unit box modal analysis, and compare with the vibration frequency of therocket engine, make the inherent frequency of the orbital replacement unit not in thescope of resonance frequency, by strengthening the rigidity of the locating pins; haveharmonic response analysis of the orbital replacement unit in the process of launchingand on-orbit working, checking the vibration resistance.Study the dynamics modeling theory and contact-impact force model of thedynamics analysis software ADAMS, and build a dynamic model of orbit replacementunit in ADAMS, through the simulation analysis, verifying the installability of modulein virtual assembly process; analyze contact-impact force in the process of positioningand locking, proving the correctness of the dynamic model; have simulation analysis ofthe horizontal position deviation and positioning cone angle, which are two of the factoreffecting orbital replacement unit assembly, getting an engineering guidance significance conclusion.