Trajectory planning method based on Newton iteration, convex optimization and active thrust adjustment

To solve the problem of inability to satisfy quantitative aerodynamic bending-moment constraints in launch vehicle trajectory planning. A trajectory planning method that combines Newton iteration, convex optimization, and active thrust adjustment is proposed. Firstly, a four-dimensional Newton iteration method is employed to design a standard trajectory, disregarding wind and process constraints. Then, considering the maximum aerodynamic bending-moment of the ascent phase and wind influence, one-dimensional Newton method is applied to obtain the thrust coefficient, ensuring the aerodynamic bending-moment constraint within the wind area. Considering the impact of thrust active adjustment on orbit entry parameters, a sequential convex optimization with two-step correction and relaxation factor adaptive adjustment method is adopted in second-stage to meet the orbit entry constraints. Finally, the effectiveness of the proposed algorithm is verified through three different trajectories. The simulation results show that the proposed method can limit aerodynamic constraints to less than 2800 Pa·rad and ensure that the orbital altitude deviation is less than 60 m without compromising capacity and energy optimization. © 2023 Editorial Department of Journal of Chinese Inertial Technology. All rights reserved.