Research On Aero-Assisted Interception Trajectory Optimization Of Spacecraft

With the constant development of science and technology,all kinds of space power with satellite as the main part has flourished.And the rapid development of satellite technology promotes the development of anti-satellite technology.Traditional ground-based and air-based anti-satellite weapons have the problems of slow response,long launch preparation time,high fuel consumption,low payload ratio,so the interceptor method which use aero-assisted technology and could reduce launch preparation time and fuel consumption is proposed.In this paper,the aero-assisted spacecraft was chosen as the study object.Aiming at the problem of aero-assisted interception trajectory optimization,minimum-fuel was taken as the objective function and the continuous optimal control problem was transformed into the discrete one based on the direct shooting method and the Gauss pseudospectral method.The problem of interception optimization was solved using Sequential Quadratic Programming,and the optimization results were compared.Advantages and disadvantages of the two discretization methods were discussed and the study of aero-assisted interception optimization was completed.Firstly,the current research status of aero-assisted orbit transfer and trajectory optimization techniques was investigated and analyzed.The research significance of aero-assisted interception trajectory optimization was presented.Secondly,the dynamic model of aero-assisted spacecraft was constructed,including the definition of coordinate systems,transformation relations between them and derivation of the dynamics equations which were normalized.The atmospheric model,aerodynamic model,objective function and constraints were given for solving the problem of interception optimization.Then,the discretization of the control variables based on the direct shooting method was studied.The solution to the optimization based on SQP was presented.A theoretical solution to the calculation of the target's longitude and latitude was given to accelerate optimization process.In order to solve the problem that it was difficult to get initial feasible solution using the direct shooting method,the initial solution prediction method was presented based on genetic algorithm.And the effectiveness of the algorithm was verified by solving the aero-assisted interception trajectory optimization,including calculating the orbit parameters which satisfied constraints and analyzing the influence of target's inclination change on trajectory of spacecraft.Finally,the discretization of the control variables and status variables based on GPM was researched and the detailed realization of GPM was given.The effectiveness of the algorithm was verified by solving the aero-assisted interception trajectory optimization,including calculating the orbit parameters which satisfied constraints and contrasting the results with ones using the direct shooting method.And advantages and disadvantages of the two discretization methods were discussed.