Design and experiment of interval type 2 fuzzy hierarchical sliding mode control for pendubot with uncertainties

In this article, a novel interval type-2 fuzzy hierarchical sliding mode control (IT2FHSMC) is proposed for controlling a pendubot system under uncertain conditions. The proposed methodology involves the construction of a hierarchical sliding-mode controller (HSMC) to provide rapid response and finite-time convergence, resulting in an excellent performance characteristics. Interval type-2 fuzzy logic control is applied to optimize HSMC for avoiding chattering phenomena and reducing the effects of uncertainty or noises. Moreover, key parameters of HSMC are tuned by using the balancing composite motion optimization algorithm. By employing the Lyapunov synthesis technique, the system's overall stability is ensured. Computer simulations and physical experiments are carried out to prove the efficacy of the IT2FHSMC compared with HSMC and type-1 hierarchical sliding-mode control and adaptive backstepping nonsingular fast terminal sliding-mode control for robust fault tolerant control.