遭受执行器攻击的工控系统输出反馈滑模控制

针对工业控制系统存在测量噪声及外界执行器攻击问题，提出一种基于无偏状态估计的输出反馈离散滑模控制方法。在执行器攻击存在的情况下，构造等效滑模控制律。由于攻击信号与系统状态未知，通过引入无偏状态观测器从遭受噪声干扰的传感测量数据中获得系统真实状态的最小方差无偏估计量。在此基础上，利用一步延时攻击估计得到攻击信号的近似估计值，使所设计的鲁棒滑模控制律得以实现。给出了在此控制律作用下滑模面的收敛性分析及闭环系统最终有界稳定的证明。数值仿真实验结果验证了面向执行器攻击的无偏状态估计器的有效性，也表明与传统滑模控制方法相比，提出的输出反馈滑模控制方法对执行器攻击具有更强的抑制力，能够有效提高系统的鲁棒性能。

Output-feedback sliding mode control for industrial control systems subject to actuator attacks

An output-feedback discrete sliding mode control based on unbiased state estimation is proposed for industrial control systems under actuator attack and measurement noisy. In the presence of actuator attack, an equivalent sliding mode control law is constructed. Since the attack signal and the state of the system are unknown, an unbiased state observer is introduced to provide the minimum variance unbiased estimator of the system real state from the sensor measurement data subject to noise interference. In order for the designed robust sliding mode control algorithm to be implemented, a one-step delay attack estimation is introduced to obtain the approximate estimate of attack. The convergence of the sliding surface and the bounded stability of the closed-loop system under the proposed control algorithm is proved. Numerical simulation results demonstrate the effectiveness of the unbiased state estimator, and show that compared with the traditional sliding mode control method, the proposed output feedback sliding mode control algorithm has better suppression for the actuator attack and can effectively improve the robustness of the system.