ADCS Design for a Sounding Rocket with Thrust Vectoring

Abstract

This paper addresses the development of an attitude determination and control system (ADCS) for a sounding rocket using thrust vector control (TVC). To design the ADCS, a non-linear 6 degrees-of-freedom (DoF) model for the rocket dynamics and kinematics is deduced and implemented in simulation environment. An optimal attitude controller is designed using the linear quadratic regulator (LQR) with an additional integral action (LQI), and relying on the derived linear, time-varying, state-space representation of the rocket. The controller is tested in the simulation environment, demonstrating satisfactory attitude tracking performance, and robustness to model uncertainties. A navigation system is designed, based on measurements available on-board, to provide accurate real-time estimates on the rocket’s state and on the aerodynamic forces and moments acting on the vehicle. These aerodynamic estimates are used by an adaptive version of the controller that computes the gains in real time after correcting the state-space model. Finally, the ADCS is the result of the integration of the attitude control and navigation systems, with the complete system being implemented and tested in simulation, and demonstrating satisfactory performance.