Zero Dynamic Active Suppression Control for Underactuated Reusable Launch Vehicles With Nonminimum Phase Property

This paper investigates the attitude controller design for an underactuated reusable launch vehicle (RLV) with nonminimum phase property. To address the nonminimum phase problem, a zero dynamic active suppression control (ZDASC) method based on Byrnes-Isidori (B-I) standard model transformation is proposed. First, a computable criterion for the nonminimum phase property of RLVs is presented, by which we can effectively determine the nonminimum phase property based on aerodynamic parameters in the RLV model. Second, an augmented system consisting of internal dynamics and dynamic compensator is constructed, and a ZDASC method is proposed for the RLV attitude control system with nonminimum phase property, which can enable adaptive stabilization of the RLV’s zero dynamics under different operating conditions and uncertainties. ZDASC achieves output accurate tracking without solving the ideal internal dynamics, which reduces the computational complexity and enhances system robustness. Finally, simulation results of the RLV attitude control are provided to verify the effectiveness and robustness of the proposed controller in tracking the guidance commands as well as stabilizing the internal dynamics.