This paper considers the problem of efficiently and securely controlling cyber-physical systems that are operating in uncertain, and adversarial environments. To mitigate sensor, actuator attacks, and performance loss due to such attacks, we formulate a secure control algorithm that consists of a proactive and a reactive defense mechanism. The proactive mechanism, which is based on the principles of moving target defense, utilizes a stochastic switching structure to dynamically and continuously alter the parameters of the system, while hindering the attacker's ability to conduct successful reconnaissance to the system. The unpredictability of the current actuator and sensor is optimized using an information entropy measure, which is induced by probabilistic switching. The reactive mechanism on the other side, detects potentially attacked components, namely sensors and actuators, by leveraging online data to compute an integral Bellman error. A rigorous mathematical framework is presented to guarantee the stability of the equilibrium point of the closed-loop system, and provide a quantified bound on the performance loss when utilizing both reactive and proactive mechanisms. Simulation results show the efficacy of the proposed approaches on a benchmark aircraft model.

中文翻译：

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网络物理系统的移动目标防御控制框架

本文考虑了有效和安全地控制在不确定和对抗性环境中运行的网络物理系统的问题。为了减轻传感器、执行器攻击和此类攻击造成的性能损失，我们制定了一种安全控制算法，该算法由主动防御机制和被动防御机制组成。主动机制基于移动目标防御的原理，利用随机切换结构来动态、持续地改变系统参数，同时阻碍攻击者对系统进行成功侦察的能力。当前执行器和传感器的不可预测性使用由概率切换引起的信息熵测量进行了优化。另一边的反应机制，通过利用在线数据来计算积分贝尔曼误差，检测潜在受到攻击的组件，即传感器和执行器。提出了一个严格的数学框架来保证闭环系统平衡点的稳定性，并在利用被动和主动机制时提供性能损失的量化界限。仿真结果显示了所提出的方法对基准飞机模型的有效性。