Abstract: During the phase of large span flight, aerodynamic parameters of guided-munitions have a large-amplitude high-frequency nonlinear chattering accompanied by varying velocity, altitude and angle of attack, adversely affecting the roll stability. Moreover, the failure and time-lag features of the actuator increase the difficulty in roll stability control. To address these problems, this paper proposes a robust adaptive fault-tolerant roll stability control method. A mathematical model of the roll channel considering the actuator fault is first established. Taking the nonlinear term and model uncertainties as external disturbances, a robust roll stability control method based on the adaptive sliding mode control theory is then presented to compensate the severe influence resulted from the nonlinear term and actuator fault. Additionally, the actuator time-lag is considered and the backstepping method implemented to suppress the actuator lag and increase the roll response speed. Simulation results show strong robustness of the proposed control method in aerodynamic disturbances and fault handling.

Key words: guided-munition, roll stability, adaptive sliding mode control, actuator faults, actuator dynamic lag, backstepping technique