Integrated guidance and control for reusable launch vehicle in reentry phase

An integrated guidance and control scheme is developed for next generation of reusable launch vehicle (RLV) with the aim to improve the flexibility, safety and autonomy. Firstly, an outer-loop optimal feedback reentry guidance law with online trajectory reshaping capability is designed. Then, a novel reentry attitude control strategy is proposed based on multivariables smooth second-order sliding mode controller and disturbance observer. The proposed control scheme is able to guarantee that the guidance commands generated from the guidance system can be tracked in finite time. Furthermore, a control allocation is integrated in the system in order to transform the control moments to control surface deflection. Finally, some representative simulation tests are conducted to demonstrate the effectiveness of the proposed integrated guidance and control strategy for six-degree-of-freedom RLV.