Attitude Control of Spacecraft by State Dependent Riccati Equation and Power Series Expansion of Riccati Methods

Attitude control of spacecraft in order to nonlinear and high order dynamics is fundamental and challenging issue. With respect to these nonlinearities, linear control theories are not suitable choices and spacecraft may be unstable or lose performance. In this paper, State Dependent Riccati Equation (SDRE) method is utilized to 3-axis stabilization using four reaction wheels. State dependent Riccati equation method is systematic approach for optimal control of nonlinear systems which satisfies constraints of systems. In order to solve time consuming problem of this method in practical systems, Theta-D method is used. Results demonstrate the effectiveness of Theta-D in compare with Riccati method.