Coding-Decoding Protocol-Based Data-Driven Adaptive Sliding Mode Control Under Energy-Constrained DoS Attacks

The security tracking control problem is addressed for nonlinear discrete-time networked control systems (NCSs) subject to energy-constrained denial-of-service (EC-DoS) attacks. A probabilistic quantization-based coding-decoding protocol (CDP) is designed to mitigate bandwidth limitations and enhance transmission security. Then, a CDP-based data-driven adaptive sliding mode control (DDASMC) method is presented on the basis of a linear data model (LDM) of the nonlinear NCSs. A detection algorithm is designed to detect EC-DoS attacks so that the proposed CDP-based DDASMC can automatically switch between two cases with and without EC-DoS attacks, respectively. In the duration that the attack does not occur, an integral sliding function and a reaching law are designed to achieve fast convergence while ensuring a good control performance. In the duration that the attack occurs, a prediction mechanism is introduced to construct a predictive LDM for estimating future control information. Further, a sliding mode predictive control is developed to address the EC-DoS attacks and enhance the control performance. All the algorithms of the proposed DDASMC are computed only using the input-output (I/O) data instead of any other information of the physical models. Simulation study validate the results. Note to Practitioners—NCSs have been extensively applied in numerous fields, such as smart grid and aerospace. However, the open network environment provides attackers with many opportunities for cyber-attacks, resulting in the deterioration of control performance. Accordingly, it is urgent to analyze the security problems of NCSs that are vulnerable to cyber-attacks. This study considers the security tracking control problem of NCSs under EC-DoS attacks. A probabilistic quantization-based CDP is introduced for the feedback channel to reduce the bandwidth of communication networks and improve the security of data transmission by compressing the data before transmission. Then, a detection mechanism is proposed to determine whether NCSs are attacked, and a DDASMC with a switching mechanism is developed to address both cases with and without EC-DoS attacks. The presented control method is data-driven and includes an adaptive switching mechanism that not only saves resources but is also more suitable for practical applications.