Sampled-Data-Based ${H_{\infty}}$ Control Design for 2-DoF Helicopter System under Stochastic Actuator Fault

This paper explores the problem of stabilization and the $H$∞performance of a 2-degree-of-freedom (2- DoF) helicopter system (HS) subject to bounded external perturbation via sampled-data control. Meanwhile, the random variable, which follows a Bernoulli distribution, is established to characterize the stochastic actuator faults. Then, a looped Lyapunov-Krasovskii functional (LKF) is constructed with complete information throughout the sampling interval. Based on the looped LKF and robust control, new stability criteria for the closed-loop HS are obtained in the form of linear matrix inequalities (LMIs). Thus, the proposed sampled-data control for the given HS model ensures the asymptotic stability and satisfies the $H$∞performance index. Finally, the effectiveness of the proposed theoretical concepts are validated through numerical results, in achieving robust stability and diminishing perturbation attenuation levels.