Reliability Analysis Of Spacecraft Separation Based On Monte Carlo Method

Spacecraft like rockets and missiles demand accomplishing the operation of separations(e.g.the separation of strap-on boosters,stage separation)in the process from the launch to the end of the flight mission.The success of separation is closely associated with the trajectory safety of spacecraft,so it is of great importance to study the reliability of separation.However,the operation of separation requires the collaborative work of the system of trajectory,control,structure,initiating explosive devices and power,etc.Nowadays,the system of separation is divided into the system of control and initiating explosive devices and so on during its analysis and calculation.It lacks the reliability study on certain process of separation alone.The motion's reliability of separation is studied and a universal software of the reliability of separation is developed.The main work is summarized as follows:The trajectory safety of spacecraft's separation under various constraints is studied.Based on the theory of dynamics of multibody systems with variable topology,the process of a spacecraft's separation is divided into multiple stages according to its topology structure.Dynamics models are established and mathematic models of corresponding forces and moments are established in different stages,respectively.Then the kinematics model of the relative motion of the separated bodies is proposed.Thus,the distance of certain characteristics points of these spacecraft and the point of landing can be obtained and the criteria of safety separation are determined accordingly.Research on the reliability analysis of separation motion is conducted using Monte Carlo method.First,the rationale for the study on separation reliability analysis with Monte Carlo method is put forward and reliability,i.e.the probability of success,is chosen as the mathematical index to measure the reliability of separation system.Then the possible deviations and disturbances during separation are analyzed and their probability distribution functions are given.Relative random sampling experiments are designed based on the Monte Carlo method,and the mathematical model of the estimation of reliability is established.The universal software of the reliability of separation is designed and developed.Considering the analysis of the users' functional need and performance need and based on the concept of universal software design,the general structure,main modules and their sub-modules are designed in detail.Then the relationship of the connection of different modules is introduced.Finally,the graphical users interface is designed and the management of input and output files is introduced.In conclusion,the motion of multiple separation processes is analyzed in detail in this dissertation.Furthermore,the reliability of motion during separation is studied.The developed software will provide important reference for the design of separation system in the future study.