在這項研究中，針對有時變延遲和數據包丟失的非線性離散時間網絡控制系統提出了一種基於觀測器的強健H_∞攻擊容忍追蹤控制策略。除此之外，基於觀測器的強健H_∞攻擊容忍追蹤控制策略對於非線性離散時間網路控制系統的設計過程中，考慮了不可用的外部干擾、測量誤差、網絡引起的時變延遲和數據包丟失。為了減輕追踪控制過程產生的巨大計算負擔，我們將網絡控制系統連接到遠程工作站，以便遠程計算機可以計算複雜的追踪控制命令。通過使用離散時間的平滑動態模型，可以將傳感器和執行器上的惡意攻擊信號嵌入非線性離散時間網路控制系統中，避免它們的損壞並方便地進行估計。因此，可以通過傳統的Luenberger觀察器同時估計系統狀態和惡意攻擊信號。為了同時消除不可用的外部干擾、測量誤差、網絡引起的時變延遲、數據包丟失和惡意攻擊對狀態估計和追踪性能的不良影響，一種基於觀測器的強健H_∞攻擊容忍追蹤控制策略引入非線性離散時間網路控制系統。利用Lyapunov函數的特點，基於觀測器的強健H_∞攻擊容忍追蹤控制策略需要解決一個非常複雜的非線性離散時間 Hamilton-Jacobi 不等式（HJI）。。由於非線性離散時間HJI不易解析或數值求解，因此採用全局線性化插值技術，通過一組局部線性化系統對非線性離散時間網路控制系統進行插值，使得這些非線性離散時間HJI被轉換為一組線性矩陣不等式，可以通過 MATLAB LMI TOOLBOX 輕鬆解決。最後，提供了一種名為Penguin BE飛行器的無人機在惡意的傳感器攻擊和執行器攻擊下的追蹤控制，以驗證所提方法的有效性。

In this study, a robust H_∞ attack-tolerant observer-based tracking control strategy is proposed for the nonlinear discrete-time networked control system (NCS). Further, unavailable external disturbance, measurement noise, network-induced time-varying delay, and data packet dropout are taken into account in the design procedure of the robust H_∞ observer-based reference tracking control strategy of the nonlinear discrete-time NCS. In order to alleviate the huge computational burden generated by the tracking control process, we connect the NCS to the remote workstation so that complex tracking control commands can be calculated by the remote computer. By using the discrete-time smoothed dynamic model, the malicious attack signals on the sensor and actuator can be embedded in nonlinear discrete-time NCS to avoid their corruption and be conveniently estimated. Thus, the system state and the malicious attack signals can be simultaneously estimated through a conventional Luenberger observer. In order to eliminate the bad effects of unavailable external disturbance, measurement noise, network-induced time-varying delay, data packet dropout, and malicious attack on the state estimation and reference tracking performance simultaneously, a robust H_∞ attack-tolerant observer-based reference tracking control strategy is introduced to the nonlinear discrete-time NCS. By utilizing the characteristic of Lyapunov function, the robust H_∞ attack-tolerant observer-based reference tracking control strategy needs to solve a very complex nonlinear discrete-time Hamilton--Jacobi inequality (HJI). Since the nonlinear discrete-time HJI is not easy to be solved analytically or numerically, the global linearization interpolation technique is employed to interpolate the nonlinear discrete-time NCS by a set of local linearized systems so that the nonlinear discrete-time HJI is converted to a set of linear matrix inequalities (LMIs) which can be easily solved by the MATLAB LMI TOOLBOX. Finally, a reference tracking control of an unmanned aerial vehicle (UAV) named Penguin BE aircraft discrete-time NCS under malicious sensor and actuator attacks is provided to validate the effectiveness of the proposed method.

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