Attitude Tracking Control Using an Online Identification and a Linear Quadratic Regulator–Based Strategy in the Presence of Orbital Eccentricity

Abstract

This paper presents attitude trajectory control for a satellite system. The pitch loop of the satellite is controlled by momentum wheel; whereas the roll/yaw loops are stabilized by two different magnetic torques along their axes. The controller is on the basis of both the linear quadratic regulator (LQR) control theory and recursive least square (RLS) algorithm that is used to identify the equivalent linear canonical second order system for each axis at discrete points on references. Then, the linear identified model is used to design the LQR-based controller. This process is done in each time span. The efficiency of the controller to bring the position error close to zero is shown by some numerical simulations. The performance of the proposed controller is remarkable in stabilizing the satellite attitude even in the presence of orbital eccentricity.