Dynamic Modeling And Simulation Of OTV On-board Launch

Reliable on-board launch ability is the precondition of executing the task of OTV(Orbit Transfer Vehicle), which is a maneuvering platform. Modeling and simulation of dynamic system is the effective way to develop the technology of on-board launch.This dissertation takes OTV platform, seperation mechanism and payload as a launch system.The dynamic simulation models of the launch process are established, including in-orbit phase, launch phase and separating phase.The stability of on-board launch is analyzed considering the influence of separation mechanism error. And the safety of relative motion after launch is studied.The main achievements in this dissertation are summarized as follows:1,Aiming at the study of safety and stability of on-board launch process, a concise unrooted system model is build, using Roberson-Wittenburg methods of multibody system dynamics.Compared with the dynamic model based on two individual rigid bodies(OTV platform and payload), the model based on multibody system has the advantage in analysising coupling effect of orbit and attitude motions.2,The orbit motion model of OTV is built, which takes earth oblateness perturbation and aerodynamic drag perturbation into account.The orbit motion model and the unrooted system model compose a complete kinematic and dynamic model for on-board launch process simulation.3,Based on C-W (Clohessey-Whiltshire) equation, relative trajectory of OTV and payload is calcutated. The safety of relative motion after launch is studied4,Taking Object-Oriented design method as guidelines,the hierarchy analysis of simulation system is carried out,and the framework design is completed.Then the on-board launch dynamic simulation software is developed.5,The assessing index of on-board launch safty and stability is presented. Using the on-board launch dynamic simulation software, simulation of whole launch process is completed. Based on the simulation results, the factors affecting the assessing index are analyzed.An effective OTV on-board launch dynamic model is proposed in this dissertation.The on-board launch dynamic simulation software has been applied to the design of separation mechanism of OTV.