Disturbance observer-based SMC for nonlinear cyber-physical systems with FDI attacks and multi-source disturbances

This paper studies the issue of sliding mode control for nonlinear cyber-physical systems subject to actuator false data injection attacks and multi-source disturbances at the same time. To begin with, nonlinear disturbance observers are developed to estimate the unknown disturbances. Then, to counter the effects from false data injection attacks, an attack compensator is designed based on higher-order sliding mode observer, which can online estimate the attack values. Subsequently, by integrating the attack and disturbance estimations, a dynamic sliding manifold is constructed, and then a novel sliding mode controller is designed. Under the proposed approach, the false data injection attacks and multi-source disturbances can be online estimated and compensated, thereby enhancing disturbance rejection ability and security for nonlinear cyber-physical systems. In addition, satisfactory control performance can be achieved with smaller switching gain under the proposed approach, and the chattering in sliding mode controller can be effectively attenuated. Finally, the proposed approach is applied for a single-link manipulator system, and simulation results demonstrate the effectiveness and superiority.