Research On Trajectory Optimization And Guidance Of Orbital Transfer Vehicle

With the development of China’s space transportation system, the requirements ofthe launch vehicles’ transport capacity are improving. Nowadays, both at home andabroad the demands of launch vehicles are toward low cost, high reliability, rapidmobility trends, orbital transfer vehicle is developped from the foundation of thesedemands. The appearance of the orbital transfer vehicle greatly enhanced the servicecapability of the space transportation system.Currently, the research on orbital transfer vehicle are mainly foucus on systemstructual design, advanced propulsion technology, orbital control technology, thermalprotection and other related aspects. In this article, dynamic modeling, trajectoryoptimization and guidance of orbital transfer vehicle are main points to research anddebate.According to the different vehicle flying stage, we can build2-body dynamic modeland atmospheric dynamic model, through this modeling method, we can describevehicles’ motion in different stages well and guarantee the reliability of the model.Trajectory optimization and guidance technology is the key technology of orbitaltransfer vehicle, aero-assisted orbital transfer problem and the aero-gravity assist orbitalmaneuver problem, which are researched both at home and abroad in recent years, arestudied in this paper. Considering the advantages (high convergence precision andconvergence rate) of using psedospectral method to solve trajectory optimizationproblems, psedospectral method is used to solve the optimal trajectories of aero-assistedorbital transfer problem and the aero-gravity assist orbital maneuver problem. Throughthe comparison with Hohmann Transfer, we have got the conclusion that aero-assistedorbital transfer has advantage in saving fuel, and the influence of different orbitinclination and the restriction of convective heating rates to the optimal trajectories isconsidered. In this paper, in the aspect of aero-assisted orbital transfer problem research, the effect of different heliocentric velocity is considered, and considering the influenceof aeroheat, the convective heating rates of the vehicle is constraint. Simulation resultshows that, compared with the situation without restraint, the provided turning angleand heliocentric velocity increment are all decreased. So when we design the optimaltrajectories for vehicles, we should not only make the performance function optimal, butalso keep convective heating rates in a affordable level to the vehicles during a flight, toavoid doing thermal damage to them. Finally, combined atmospheric guidance methodis used for the aero-gravity assist orbital maneuver problem research, and theeffectiveness of the algorithm is verified through simulation.In conclusion, in this thesis, we have made a theoretical analysis on some relatedissues like dynamic modeling, trajectory optimization and guidance of the orbitaltransfer vehicle, and made research and discussion on these problems by combiningtrajectory optimization method with simulation technology. This research will play animportant role when it applied in China’s space transportation system.