Efficient Thrust Management Algorithm for Variable Thrust Solid Propulsion System with Multi-Nozzles

Abstract

A thrust management algorithm that integrates combustion chamber pressure control and thrust distribution is proposed for a variable thrust solid propulsion system with multiple nozzles. In this study, a divert and attitude control system installed with pintle thrusters that can continuously and proportionally change the thrust by varying the nozzle throat area with pintle actuators is considered. The multiple pintle thrusters sharing the combustion chamber has to stabilize the combustion chamber pressure and simultaneously produce the thrust required by the vehicle. A nonlinear combustion chamber pressure controller with application of a nonlinear disturbance observers is proposed in order to consider the chamber dynamics, actuator, nozzle geometry, model uncertainty, and disturbances. Also, a thrust distribution algorithm that can efficiently allocate thrust commands to each thruster based on the pressure control is proposed. Finally, a numerical simulation is conducted to verify the performance of the proposed thrust management algorithm.