Research on entry trajectory optimization of lifting reentry vehicle

The Simpson collocation method was studied in the trajectory optimization of lifting reentry vehicle. The 3DOF model of reentry vehicle's trajectory optimization control problem was built. The optimization control problem was transformed into NLP( Non-Linear Programming) problem by using the collocation method,and the DFP method in the quasi-Newton method was used to solve the parameter optimization problem. Through the simulation,it is found that the reentry trajectory got with this method can meet the requirements for longer transverse distance,meanwhile it has higher reentry speed,and the vehicle's reentry terminal position is of high accuracy. At the same time,the optimized control variables can be used to reproduce the optimal reentry trajectory. Therefore,the lifting vehicle can meet the requirements of large landscape distance,and the direct collocation method is feasible to solve the reentry vehicle trajectory optimization problem.