Design of compound control law for near space vehicle reentry

To solve the compound control problem for high-dynamic near space vehicles (NSV) with multiple control effectors in the reentry phase, an appropriate compound control mode and its framework are proposed for NSV with both aerodynamic fins and reaction control system. Furthermore, the corresponding heterogeneous compound control law is developed. Accordingly, a command structure controller and a moment structure controller are designed for NSV in high-altitude areas and medium-altitude areas, respectively. Thus, a rapid and smooth control responding is achieved with the command structure controller in high-altitude areas; precise and strong robust attitude control performances are gained with the moment structure controller in medium-altitude areas. The simulation indicates the proposed method can satisfy the demands of NSV's attitude compound control in practice, including the attitude angles and rudder deflections smooth and stable, the tracking error below 0.5° and the overshoot less than 5% under disturbances.