Fast model predictive control scheme for attitude control systems of rigid-flexible satellite

Abstract

In recent years, the applications related to artificial satellites have considerably grown in several areas such as telecommunications, astronomy and meteorology. An important point that must be taken into account to place a satellite in orbit is the design of Attitude Control System (ACS) to control the angular position according to a fixed reference frame. Most satellites have in their structure the presence of flexible appendices such as solar panels, sails, or even antennas that may produce undesirable oscillations during satellite maneuvers and this can excite the whole system’s structure. Therefore, it is important to develop an ACS that limits the excursion of the flexible structure and meet the control requirements for attitude stabilization. In this paper, a Model Predictive Control (MPC) scheme is proposed for ACS of a Rigid-Flexible Satellite. MPC handles structurally the system’s constraints in problem formulation by solving at each sampling instant an optimization problem that express the control objectives. As a result, MPC is able to track efficiently the references for attitude control by keeping the displacement of flexible structure within predetermined limits reducing vibration of the system. Moreover, MPC also deals with constraints on control inputs since actuators are physically bounded by its maximum allowable value. Another important feature of the proposed control strategy is the parameterization of MPC which reduces considerably the complexity of the optimization problem enabling short computation times. Simulation results are shown to emphasize the efficiency of the parameterized MPC strategy and a comparison with a Linear Quadratic Regulator (LQR) is also performed