Robust finite time integral sliding mode tracker for nth-order non-affine non-linear system with uncertainty and disturbance estimator

This paper presents a novel control technique for a class of uncertain and time varying nth-order non-affine non-linear systems with an integral terminal sliding mode augmented with uncertainty and disturbance estimator (UDE). These non-linear systems are difficult to control due to non-affine nature of their inputs, failure of feedback linearization approach and control singularity problems. Therefore, an integral terminal sliding surface is chosen to ensure the faster and finite time convergence of the system dynamics to the desired dynamics. UDE provides a chatter-free auxiliary controller for eliminating the impacts of complex system non-affine uncertainties. Moreover, the system uncertainties and external disturbances are tackled without requiring information about their upper bounds. Furthermore, the superior tracking performances and stability are guaranteed through Lyapunov’s direct method. Also, three simulation examples are presented to illustrate the efficacy of the proposed methodology by comparing with the previous methods in literature.