Optimal Trajectory Design And Control For Space Interception

As the war situation changed, more and more country pay attention to space interception. Whether the interception mission successfully completed is depended on the amount of fuel consumption in the interception process, thus orbit optimization and control is of great significance. This paper focuses on orbit optimization, initial control, terminal control and hovering, based on above corresponding software was developed.Nonlinear programming and primer vector theory was used for orbit optimization. Optimal multiple-impulse interception was studied by nonlinear programming, considering the J2 perturbation. Based on normal Interception model, the nonlinear programming model was set up. Using this method,the times , magnitudes and directions of three-impulse Interception with time constraint were obtained. Finally, optimal results were compared for one-impulse interception, two-impulse interception and three-impulse interception with different time constrain. The simulation results show that the initial control is rational and efficient. Whether the fuel consumption was optimal in time-fixed interception was mainly studied by primer vector theory. Based on orbit dynamic theory,the close interception model was set up. According to primer vector theory, whether the interception optimal and how to optimize was given. Finally, a great lot of simulations were done to investigate the fuel consumption with different time and impulses restraint.Initial control for space Interception was studied by differential correction method. Based on the mathematical model and the state transition matrix for orbit Interception, the magnitude and direction of velocity were attained. The miss distance caused by the effects of perturbation was compensated in this initial control. The simulation results show that the initial control is rational and efficient. Terminal control for space Interception was studied by quasi-sliding mode control. For the nonlinear models of the space interception and characteristics of the engines terminal guidance laws were proposed based on quasi-sliding mode control theory. The guidance law is easy to be realized in engineering. Numerical simulation is carried out with available and satisfactory results.Circular orbit of satellite hovering over space target was studied. Dynamics analysis of hovering orbit was presented, not considering J2 perpetual. By implementing a continuous pulse thrust control, the satellite was kept in a period of time on a new hovering orbit other than Kepler orbit. Finally, numerical simulation shows that it was feasible to hover over space targets in a period of time.