$H_{2}-H_{\infty}$ Model Reference Adaptive Control of Tethered Satellite System

This study aims to investigate the control of a triangular configuration and triple mass tethered satellite system using a novel robust H
₂
-H
_∞
Model Reference Adaptive Control (HMRAC) scheme. The system is actuated by thrusters to generate control forces. The dynamical model of the semi-ideal system, which acts as a reference model is described with a known external disturbance, called the J2 perturbation. The proposed MRAC design methodology is based on the stable semi-ideal nonlinear reference model, which is regulated by a state feedback controller using H
₂
-H
_∞
State Dependent Riccati Equation (SDRE) techniques. Then, the real system with the unknown disturbances is controlled by the feedback of the reference model control scheme. The main benefit of using the HMRAC is having robustness of the reference model, which decreases the computational burden of the classical MRAC. The numerical simulation results are presented and compared with the Linear Quadratic Regulator to demonstrate the effectiveness of the proposed control method. Also, the effectiveness of the proposed controller in improving attitude maneuverability is demonstrated.