Autonomous ascent guidance with multiple terminal constraints for all-solid launch vehicles

Abstract

Removing the thrust termination mechanism of solid rocket motors is an inevitable trend but reduces the ability of terminal multi-constraints. This paper presents an improved analytic algorithm for rapid and automated ascent guidance of responsive small solid launch vehicles shutting off by fuel exhaustion. The proposed new analytical solution is solved for the two-point boundary value problem with coast arc and constraints of the given burn arc. A velocity increment control method is derived from the minimum steering angle constraints to dissipate the extra energy and an improved pointing algorithm is constructed to restrain the coupling vectors caused by the process of velocity increment control. Then, the solution of the improved pointing algorithm provides the direction of the velocity increment control and the effect of the additional coupling vectors on terminal constraints is suppressed by this direction. Finally, the application of the developed theoretical algorithm in this paper is conducted by using the last stage of all-solid launch vehicles. The proposed guidance method is verified by Monte Carlo simulations and the testing results demonstrate the adaptability, strong robustness and excellent performance for different orbital-insertion missions.