Longitudinal Ascending Trajectory Design and Tracking Control for Two-Stage-To-Orbit Aerospace Vehicles Before Stage-Separation

The design of the pre-separation ascending trajectory and the tracking control problem are key issues in the hypersonic stage-separation of multi-body two-stage-to-orbit (TSTO) aerospace vehicles (ASV). This paper addresses the situation that the spacecraft is on the back of the carrier. In this study, considering the conditions required for a safe separation, a strategy is proposed to make the ASV climb according to a parabolic shaped trajectory with a terminal constraint of zero normal overload at the moment of separation. Then, the parabolic separation trajectory strategy is modelled analytically, a profile design strategy based on range derivative is proposed. And combined with the trajectory linearization control method to design the tracking control law for designed parabolic separation trajectory; finally, the simulation is carried out through Matlab to analyse and verify the feasibility of the strategy and to test the tracking control effect of the parabolic separation trajectory designed in this paper.