This paper presents a higher-order fully actuated system (HOFAS) approach for integrated guidance and control of launchers during orbit insertion, addressing the limitations of traditional decoupled architectures in handling the coupled translational and rotational dynamics, as well as underactuation constraints. By integrating the attitude dynamics directly into the position tracking framework, a unified HOFAS model is formulated that inherently accommodates cascade dynamics and eliminates the need for sequential attitude reference generation. A HOFAS-based control architecture is developed using a recursive control strategy to construct a set of decoupled linear closed-loop subsystems, enabling parametric eigenstructure assignment across all subsystems. Furthermore, a feedback gain optimization framework is introduced to enhance dynamic performance under physical constraints and actuator limitations, making full use of the design freedom of every closed-loop subsystem. Comparative simulations demonstrate that under equivalent control effort the proposed HOFAS-based framework achieves faster convergence, reduced oscillation, and improved compliance with actuator limitations compared to conventional state-space-based methods. The results validate the effectiveness and robustness of the HOFAS approach in addressing coupled and cascade system dynamics and highlight its potential as a new paradigm for aerospace control under stringent nonlinear constraints.
Sun et al. (Sun,) studied this question.