Security-conscious dynamic output feedback control for periodic piecewise nonlinear systems under output-reliant disturbance observer

This article focuses on addressing the finite-time dynamic output feedback control problem for periodic piecewise nonlinear systems in the midst of multifaceted disturbances and cyber attack scenarios. Moreover, multifaceted disturbances encompass mismatched disturbances and multiple matched disturbances. Therein, the mismatched disturbances are presumed to be norm-bounded vectors, whereas multiple matched disturbances emanate from exogenous systems. Additionally, two instances of nonlinear dynamics in the plants are looked at, pertaining to both known and unknown cases. Furthermore, to estimate the multiple matched disturbances, output-reliant multiple periodic piecewise disturbance observers for both the nonlinear instances are framed separately on the grounds of the control input and the measurement output. Moreover, the mismatched disturbances are attenuated using the mixed H∞/passivity approach. From thereon, a holistic control framework blending these observers with a dynamic output feedback mechanism is put together to guarantee the intended closed-loop performance in a finite-time span by rejecting the matched disturbances. Therein, a probabilistic model with Bernoulli-distributed variable is laid out to characterize the incidence of deception attacks, potentially improving the resilience of the control. Following that, by means of Lyapunov stability theory, the stability of the target system is analyzed and the precise setups of the periodic piecewise controller and disturbance observer gains are put forward. Ultimately, simulation results are put forward to confirm the reliability and effectiveness of the control protocol.