Control of flexible spacecraft via state-dependent riccati equation technique

This paper studies the attitude control problem of flexible spacecraft via state-dependent Riccati equation (SDRE) technique. Firstly, the dynamic equations of a flexible spacecraft are established and the error dynamic equations are derived. An attitude controller is designed via SDRE technique. The controller is solved using three methods, i.e. Schur method, modified Newton method, and θ-D method. The controller will transform into a suboptimal controller on attitude maneuver if the desired attitude is fixed. Finally a numerical simulation of a flexible spacecraft is carried out to validate the controller and compare different solving methods. The simulation results show that the modified Newton method has the highest accuracy of resolution, the Schur method takes second place, and the θ-D method has the worst accuracy. However, the θ-D method has an outstandingly computing efficiency compared with others. Furthermore, it can also guarantee adequate quality of attitude control. The highly computing efficiency of θ-D method makes the SDRE controller possible for practical application.