Analysis and attitude control of spacecraft with input uncertainty

A moving mass control of rotating spacecraft is a kind of new control mode, it differs from other control modes because it generates an angle of attack and an angle of sideslip directly from the mass motion. The nonlinear equations of motion for rotating Maneuverable Spacecraft are derived. the variable structure attitude controller is presented according to the nonlinear equations, It's based on two-timescale separation and with two loops, faster loop and slower loop respectively. Inertial uncertainties and aerodynamic moment uncertainties are considered simultaneously, In order to track the command signals perfectly, the sliding surface is of integral form, results of the simulation shows that this kind of attitude control system is potentially practical and robust in the presence of inertial uncertainties of guided missile and uncertainties of aerodynamic moments. Compared with the common attitude control system, it has the following advantages:(1) non linear model is directly controlled, (2)it has robust. Because the non-linear factor is considered, it has the practical use for the engineering field.