Robust GDI-based adaptive recursive sliding mode control (RGDI-ARSMC) for a highly nonlinear MIMO system with varying dynamics of UAV

The novelty of the proposed work lies in the control technique, referred to as the robust generalized dynamic inversion based adaptive recursive sliding mode control (RGDI-ARSMC), for addressing various challenges to control a highly coupled and perturbed system called twin rotor MIMO systems (TRMS) UAV. The continuous disturbances, varying parameter values, actuator failure, and unmodeled states are the challenges related to the proposed controller. The method aims to effectively mitigate unwanted signals, including coupling effects, unknown states, gyroscopic disturbance torque, parametric uncertainties, and other disturbances. The control design process is divided into two phases: the first involves estimating the deviation between the actual and desired output angles and conducting a stability phase analysis. The confined stability-based Lyapunov stability was verified. While the second phase involves the addition of a robust term and the use of an adaptive recursive design procedure to determine the controller parameters for pitch and yaw angles. The proposed control strategy is compared with other techniques such as classical sliding mode control, backstepping, and RGDI-SMC controls. The proposed strategy is also implemented in real-time to characterize its performance. On the basis of obtained results, the considered perturbations were effectively addressed by the augmentation of adaptation laws and recursive control design.