Secure Tracking Control via Fixed-Time Convergent Reinforcement Learning for a UAV CPS

Dear Editor,This letter is concerned with the secure tracking control problem in the unmanned aerial vehicle(UAV) system by fixed-time convergent reinforcement learning(RL). By virtue of the zero-sum game,the false data injection(FDI) attacker and secure controller are viewed as game players.

基于MASAC强化学习算法的多无人机协同路径规划

针对动态不确定环境下异构多无人机协同路径规划问题,提出了一种新的多智能体深度强化学习算法.首先,开发了一个空域场景下多无人机到达目标地点的强化学习环境,环境引入了无人机动力学方程,并考虑了无人机异构的因素以及安全避障的需求.其次,设计了任务完成率、编队保持率、飞行时间等性能指标,用以衡量算法的优劣.然后,将多无人机协同路径规划问题建模为部分可观Markov决策过程,提出了一种多智能体柔性执行评价(multi-agent soft actorcritic,MASAC)算法寻求该问题的近似最优策略.最后,通过仿真实验验证了所提算法的有效性和优越性.

Resilient distributed economic dispatch of a cyber-power system under DoS attack

The economic dispatch problem of a smart grid under vicious denial of service(DoS)is the main focus of this paper.Taking the actual situation of power generation as a starting point,a new distributed optimization model is established which takes the environmentai pollution penalty into account.For saving the limited bandwidth,a novel distributed event-triggered scheme is proposed to keep the resilience and economy of a class of cyber-power syst ems when the communication net work is subject to malicious DoS attack.Then an improved multi-agent consensus protocol based on the gradient descent idea is designed to solve the minimization problem,and the prerequisites to minimize the system power generation cost are analyzed from the aspects of optimality and stability.Finally,the theoretical results are verified through a single-area 10-generat or unit simulation.

Robust fault detection filter design for a class of time-delay systems via equivalent transformation

This paper is concerned with the robust fault detection filter （RFDF） design for a class of linear time- invariant systems （LTISs） with output state time delays. Although existing results in literatures study the RFDF for time- delay systems, few is concerned with the output state time-delay systems. The basic idea of our study is to eliminate the time delays of system and transform it to a delay-free system （i.e., a linear time-invariant system without time delays） by the bicausal change of coordinates approach. Then, we design the RFDF for the delay-free LTIS, which is equivalent to the original system with time delays. We first introduce a class of systems with output state time delays, whose fault can be detected by using the RFDF design approach for delay-free systems. Then, since the RFDF design problem can be formulated as a standard H-infinity-model matching problem, it is solved by using H-infinity-optimization LMI techniques. In the last, the adaptive threshold of fault detection is chosen and an illustrative design example is used to demonstrate the validity of the design approach.

混合攻击下基于带宽感知型事件触发机制的负荷频率控制

针对混合攻击下的一类新型电力系统,本文提出了一种负荷频率安全控制方案,实现在欺骗与拒绝服务(denial of service,DoS)攻击下的闭环稳定与安全运行.首先,基于确认字符(acknowledgement character,ACK)技术提出了一种针对非周期性DoS攻击的“阴阳”检测机制.其次,为保持系统控制性能并节约网络通信资源,提出了一种新颖的带宽感知事件触发机制.再次,建立了一个混合攻击下包含风力发电机组与电池储能系统的多区域电力系统切换模型.利用Lyapunov-Krasovskii泛函(Lyapunov-Krasovskii functional,LKF)理论与线性矩阵不等式(linear matrix inequality,LMI)技术,给出满足H∞性能的系统指数均方稳定充分条件,并导出了事件触发负荷频率安全控制器的设计准则.最后,通过仿真实验验证了所提DoS攻击检测机制和事件触发安全控制器的有效性与优越性.