6D trajectory, guidance and control development for air-breathing phase of reusable launch vehicle

This paper presents the development of 6D trajectory, integrated guidance and control algorithm for winged cone hypersonic air-breathing vehicle. Trajectory models aerodynamics, scramjet-based propulsion, guidance and control subsystems for the ascent phase of flight regime addressing the various coupling issues between them. Reference trajectory is generated with optimal guidance law to command angle of attack, velocity and flight path angle. Integrated controller developed here considers the longitudinal, lateral states together with translational states to track angle of attack, velocity and flight path angle of the reference trajectory and to regulate side slip and roll angle. The hybrid controller consists of a decoupling controller based on a state feedback, to decouple input/output ensuring independent control of the output variables with separate command inputs. Further, a PID controller with compensator is designed to achieve the required stability margins in each channels which improves the robustness to parameter perturbations.