Integrated control design for orbit injection of launchers via fully-actuated system approach

Due to the strong coupling and nonlinearity in dynamics, launchers often employ separate designs for guidance loop trajectory planning and attitude loop tracking control. While this simplified approach reduces problem complexity, it neglects the interaction between guidance and attitude control. In this paper, an integrated control design for orbit injection of launchers is proposed using a fully-actuated system approach, which offers interpretability and high flexibility for nonlinear systems. First, a refined time-varying model of the launcher is established, accounting for mass property variations caused by propellant consumption. Next, both guidance and attitude closed-loop error dynamics are parameterised through the fully-actuated system approach. Furthermore, the Lyapunov stability of the integrated closed-loop system is demonstrated by explicitly considering the influence of attitude tracking error on control force generation. Additionally, a constraint-compatible online optimisation scheme for feedback controller gains is proposed to adaptively meet multiple desired performance indicators as the system state evolves. Finally, a numerical simulation of orbit injection of a launcher is conducted to validate the effectiveness of the proposed controller.