隐蔽攻击下信息物理系统的安全输出反馈控制

Secure Output-feedback Control for Cyber-physical Systems Under Stealthy Attacks

研究了受到隐蔽攻击的信息物理系统(Cyber-physical system,CPS)安全控制问题.采用KL(Kullback-Leibler)散度描述攻击的隐蔽性,并设计动态输出反馈控制器,使系统可达集始终保持在安全区域内,其中可达集定义为系统状态以一定概率属于的集合.首先,给出隐蔽攻击下检测器残差所在范围的一个外椭球近似集;其次,根据该近似集和噪声的范围给出控制器参数与系统椭球形不变可达集的关系;然后,通过设计可逆线性变换并构造凸优化问题,求解安全控制器参数和相应的不变可达集;最后,使用弹簧−质量−阻尼系统进行仿真,验证了所提控制方法的有效性.

Secure control problem of cyber-physical systems(CPS)under stealthy attacks is studied.The Kullback-Leibler(KL)divergence is adopted to describe the attack's stealthiness.The aim is to design a secure dynamic output-feedback controller such that the reachable set,which is defined as the set that the system's state resides in with a certain probability,resides in a safe set.Firstly,an ellipsoidal outer approximation for the set of residual under stealthy attacks is given.Secondly,based on the approximation and the ranges of noises,the relationship between controller's parameters and the ellipsoidal invariant reachable set is analyzed.Thirdly,a convex optimization problem is constructed by designing an invertible linear transformation.Parameters of the secure controller and the corresponding invariant reachable set are obtained by solving the problem.Finally,a simulation of the springmass-damping system is given to verify the effectiveness of the proposed controller.