一种改进的运载火箭迭代制导方法

To improve the optimality, robustness and adaptability of the guidance method for the launch vehicle in case of thrust fault outside the atmosphere, this paper proposes an improved iterative guidance method which derives the transversality condition with five orbital elements as the terminal constraint using the analytical expression based on the optimal control theory as the optimal control solution, thereby enhancing the optimization of the algorithm. In the iterative process, a Gauss Legendre integral method is adopted to calculate the thrust integral, and a Taylor polynomial approximation method is used to calculate the gravity integral, improving the integration accuracy in the fault mode. The proposed method adopts the dimension reduction iteration mode and the reasonable limiting of the control variables to ensure the real-timeness and convergence of the algorithm under the condition of thrust fault. The simulation results based on the Monte Carlo method and thrust fault conditions show the strong optimality, robustness and fault adaptability of the proposed method.