Energy-Efficient Control System for Small-Scale Rocket Recovery

This study investigates energy efficient control system for a small scale rocket recovery, utilizing thrust vector control (TVC) and reaction gas control (RGC) approaches. The dynamics of the rocket is managed through control input thruster forces and gimbaled angles, with the output parameters expressed in terms of velocity. Leveraging this model, several controllers: the linear quadratic regulator (LQR), linear quadratic Gaussian (LQG), sliding mode control (SMC), and proportional integral derivative (PID) controllers were designed and implemented. A linearized version of the nonlinear dynamic model of the rocket, obtained through Jacobian linearization, facilitates the application of LQR and LQG controllers. For precise pitch and yaw control, the architecture incorporates a single-nozzle TVC actuation and four-sided gas thrusters. Simulation studies, conducted in MATLAB/Simulink, evaluated the energy consumption profiles of each control strategy during rocket recovery, with the PID controller used as a baseline for comparison. Without disturbances, the LQG controller reduced energy consumption by 17.63% compared to PID, while SMC and LQR achieved reductions of 14.65% and 14.24%, respectively. Under disturbed conditions, LQG, SMC, and LQR reduced energy consumption by 30.39%, 27.38%, and 27.30%, respectively. These results highlight the potential of advanced control techniques to optimize energy efficiency. Thus, this study provides valuable insights for the development of more sustainable and cost-effective reusable rocket systems by emphasizing energy-efficient recovery control.