一种带有动力切换的飞回段迭代制导算法

Given the strict velocity and position constraints before the reentry of reusable launch vehicles into the atmosphere and to realize the crossphase guidance with power switching, the estimation, compensation, and switching of iterative targets are taken as the main research content to improve the traditional iterative guidance. On the basis of the derivation idea of the traditional iterative guidance algorithm, the multisegment iterative guidance model is established in the launch coordinate system to predict the terminal state of glided phase. Then, the analytical expression of the attitude angle is derived. By integrating the return, glide, and deceleration phases into one logical flyback phase and deploying only one guidance algorithm, the initial deviation can be dispersed in multiple flight phases to correct and reduce the guidance pressure of each single power phase. Numerical simulations demonstrate that this algorithm has less computation time, high precision, and strong robustness; the horizontal speed is less than 0.05 m/s, and the position is less than 0.5 m.