Emergency reentry trajectory planning for reusable launch vehicle based on dynamic gauss pseudo-spectral

A new dynamic pseudo-spectral method is proposed for the emergency trajectory planning problem of a Reusable Launch Vehicle in this paper, making trajectory reconstruction come true under the condition of target changed or aerodynamic ability decreased. Firstly, the emergency trajectory planning problem is transformed into a globally dynamic planning problem. Secondly, the continuous optimal problem is discretized based on the Legendre-Gauss-Lobatto Pseudo-spectral method. Thirdly, the uniformity between the Pseudo-spectral method and the Continuous Bolza problem is proved. And the performance index is optimized based on Lagrange operator. In consideration of the difficulty of convergence of the non-continuation optimal solution, the high effective initial allocation and the dynamic planning algorithm are proposed. The final numerical simulation results show the effectiveness of the approach to reconfigure the reentry trajectory with the terminal error less than 10m and 20% aerodynamic force bias.