Wings deployment UAV control system via second order sliding modes method

The problem of designing control laws in the longitudinal and lateral planes of the Modular Stand Off Vehicle (MSOV), for the wings deployment phase is considered. During the wings opening phase the main tasks of the controller is to ensure optimal conditions for wings deployment (i.e. about zero angle of attack in terms of equivalent normal force coefficient N C_N ) and to stabilize the vehicle when the wings open in spite of possible roll asymmetries and aerodynamic parameter uncertainties. It should be noted that the controller has to compensate the severe jump effect on the plant parameters due to the fast wings deployment. This work presents an extension of the 2-order sliding modes method to the roll plane and an application to the MSOV, where two different schemes of the VSS control law operate simultaneously in both pitch and roll planes along with parameters switching at wings deployment. The Roll and Pitch VSS algorithms are both presented in this paper. Results of 6 DOF Monte-Carlo simulations of VSS controllers at wings deployment and that of the MSOV flight test show that the VSS loops provide successful wing deployment, a safe transient response and lead to the successful completion of its mission.