Performance evaluation of an improved non-singular sliding mode attitude control of a perturbed quadrotor: Experimental validation

In this paper, a new control scheme, that combines the Super-Twisting (ST) algorithm with the Nonsingular Terminal Sliding Mode Control (NTSMC), is adopted to robustly stabilize the quadrotor attitude while compensating for the impact of uncertainties/perturbations. The main merit of the proposed ST-NTSMC is to take advantage of the robustness and chattering avoidance allowed by the ST algorithm and the finite-time convergence, the fast transitions, and the high trajectory tracking accuracy allowed by the NTSMC algorithm. Lyapunov criterion is used to analyze the closed-loop stability of the proposed ST-NTSMC controller. Experimental tests are conducted on a quadrotor prototype under various flight conditions in order to test and evaluate the performance of the new controller. Comparisons with multiple linear and nonlinear controllers are also performed to highlight the outperformance of the suggested approach. Experimental results demonstrate the high performance of the developed controller in terms of tracking accuracy, robustness, and chattering reduction.