Variable thrust Exo-atmosphere ascent iterative guidance

This paper presents a method for exo-atmospheric ascent guidance to accomplish the orbital insertion with full states satisfied for the new generation of launch vehicles with variable-thrust engine. The variable thrust provides the possibility to verify the Iterative Guidance Mode (IGM) to overcome its deficiency of not satisfying all the 6 terminal states constraints. A feedback guidance scheme is formed by setting the thrust needed as a feedback. The thrust needed is obtained through the differential relationship between the estimated orbital insertion error and thrust parameters. By embedding the IGM to the feedback scheme, a closed-loop guidance mode is built. Simulation results demonstrate that the adaptive variable thrust iterative guidance method proposed can complete the full-state insertion missions accurately, and the algorithm in the method is simple and easy to implement for engineering practice.