Ascent trajectory and parameter collaborative optimization for aerospace vehicles with rocket-based combined cycle propulsion

The rocket-based combined cycle (RBCC) propulsion adopted by aerospace vehicles has multiple modes, and each mode operation and transition will directly affect the ascent trajectory design. This paper focuses on the ascent trajectory optimization research of aerospace vehicles with RBCC. Firstly, the trajectory optimization issue in ascent phase scenario is constructed considering the trajectory planning requirements for different propulsion modes. In order to balance the trajectory optimization and modal transition, an angle of attack-velocity profile design based on high-order polynomials is proposed. The number of constraints is significantly simplified through the profile design, and the collaborative optimization problem of ascent trajectory and modal parameters is constructed. Subsequently, three particle swarm optimization (PSO) improvement strategies are given oriented to convergence performance and constraint processing. Furthermore, a trajectory and parameter collaborative optimization method based on improved PSO and parallel search theory is proposed. At last, the effectiveness and superiority of the proposed method are illustrated through comparative simulations with existing methods.