Researching Of The The Rigid-flexible Coupled System Analytical Dynamics Modeling

Most spacecrafts belong to the rigid-flexible coupled system which thecoupled effect have a big impact to the spacecraft dynamics characteristicsand behavior and bring problems on dynamics modeling and motion control. Ifwe can do the modeling of the rigid-flexible coupled spacecraft accurately whichhas soft attachment, and fully considering the coupled effect on spacecraftstructural dynamics, it will be conducive to understand structure dynamicsglobally. Therefore, the rigid-flexible coupled system dynamics modelingresearch has practical certain significance and theoretical value.At the beginning, this paper summarized the achievements of therigid-flexible coupled system modeling research at many fields which mostlyconcentrated in the aerospace field. All scholars are trying to seek the modelswhich can reflect the dynamics characteristics of the rigid-flexible coupledsystem accurately. The single rigid-flexible coupled system is the foundationof the rigid-flexible coupled system, only the single rigid-flexible coupledsystem dynamics modeling has been studied thoroughly, can we lay a solidfoundation of the study of rigid-flexible coupled system modeling.Then, in order to analysis the rigidization phenomenon of the rigid-flexiblecoupled system, this paper derived the dynamics equation and took a simplesimulation (Matlab/Simulink) of a flexible linkage example using three methodsincluding rectangular coordinate system, angle coordinate system, thegeneralized coordinates and energy principle. The theory analysis and simulationresults showed that taking mathematical modeling of the rigid-flexible coupledsystem at generalized coordinates in the inertial system has strong universalityand accuracy using the analytical dynamics and revealed the physicalsignificance of rigidization item.Nextly, this paper deduced the dynamics equation of two models: rigid-body&cantilever-beam and rigid-body&cantilever-slab which belong to the flexiblespacecraft (the single rigid-flexible coupled system) using the mechanics ofKane equation in Analytical dynamics, and took a simple simulation (Matlab/Simulink) when rigid-body abides by the acceleration rotation law ofmotion. The simulation results showed that the rigid-flexible coupled systemdynamics equation using Kane equation conforms to the fact in a sense, and theexistence of dynamic stiffness would cause influence to dynamic equation.Finally, the quasi value conditions and prerequisites of the rigid-flexiblecoupled body(the single rigid-flexible coupled system) based on therigid-flexible coupled body quasi Hamilton’s principle have been got by usinganalytical dynamics functional analysis method. By applying the rigid-flexiblecoupled body quasi Hamilton’s principle quasi value conditions and prerequisiteson a simplified missile, the coupling between the elastic deformation and rigidbody displacement are revealed, the missile dynamics equations in specific casescan be simplified as a rod longitudinal vibration and space free beam dynamicsequation.