Six Degree of Freedom Model for Testing Vehicle with Liquid Rocket Engine

Abstract

The purpose of the paper is to present a calculus model for a testing vehicle which can be used to validate guidance, navigation and control system for launcher family in ascending phase and for reusable launchers in all flight phase. Technical solution is based on liquid rocket engine capable to ensure by thrust vectoring control and throttling the pitch, the yaw and the velocity control, and a reaction control system used for roll control. For calculus we will develop a nonlinear model with six degrees of freedom, extended with equation for Triger Schmidt nonlinear system used on roll control. In order to obtain an attitude controller, we develop also a linear model, both models (linear and nonlinear), being similarly with those of the launcher, with the purpose to validate their guidance system. We will analyze the ascending flight, the horizontal flight and the descending flight specific for reused launchers.