数据注入攻击下ICPS的自适应事件触发弹性控制

为使工业信息物理系统(ICPS)抵御数据注入攻击, 本文研究了事件触发弹性控制策略, 采用自适应事件触发以减少通信资源, 构建攻击估计器以降低攻击对系统性能的影响. 通过H∞渐近稳定性准则推导估计器参数, 采用Lyapunov-Krasovskii函数推导事件触发、数据注入攻击、网络延迟和弹性控制器之间的定量关系. 以二自由度质量–弹簧–阻尼串联系统为被控对象, MATLAB仿真验证基于自适应事件触发的ICPS在数据注入攻击下的系统性能,结果表明所采取策略能保证系统的稳定性, 并有效减少通信资源.     

基于DoS攻击能量分级的ICPS综合安全控制与通信协同设计

针对一类有限能量拒绝服务（denial of service,DoS）攻击与执行器故障共存的工业信息物理系统（industry cyber-physical system,ICPS）,研究了综合安全控制与通信协同设计问题。首先,考虑单侧网络遭受DoS攻击的情形,构建了ICPS综合安全控制架构,并从防御者的视角通过分析不...     

假数据注入攻击下信息物理融合系统的稳定性研究

假数据注入（False data injection,FDI）攻击由于其隐蔽性特点,严重威胁着信息物理融合系统（Cyber-physical systems,CPS）的安全.从攻击者角度,本文主要研究了FDI攻击对CPS稳定性的影响.首先,给出了FDI攻击模型,从前向通道和反馈通道分别注入控制假数据和测量假数据.接着,提出了FDI攻击效力模型来量化FDI攻击对CPS状态估计值和测量残差的影响.在此基础上,设计了一个攻击向量协同策略,并从理论上分析出操纵CPS稳定性的攻击条件：攻击矩阵H和系统矩阵A的稳定性及时间参数ka的选取时机.数值仿真结果表明FDI攻击协同策略能够有效操纵两类（含有稳定和不稳定受控对象）系统的稳定性.该研究进一步揭示了FDI攻击的协同性,对保护CPS安全和防御网络攻击提供了重要参考.     

Edge event-triggered control for multi-agent systems under directed communication topologies

The edge event-triggered consensus control for multi-agent systems with single- or double-integrator dynamics under directed communication topologies is investigated in this paper. With the edge event-triggered sampling strategies, a class of novel consensus protocols is proposed to reduce control update frequency. The main features of the proposed edge event-triggered control include three aspects: (i) measurement errors are defined based on directed information flow and thus they allow that the communication topology is directed, (ii) each individual controller updates its output only when the associated edge event occurs and the control actions are independent of other agents, and (iii) the proposed edge event-triggered control does not exhibit Zeno behaviour and it is shown that the inter-event intervals are lower bounded by a positive constant. In the consensus analysis, matrix transformation techniques are used to convert the high-dimensional system into a low-dimensional system, and some sufficient consensus conditions are derived for the multi-agent systems with single- or double-integrator dynamics. Finally, the effectiveness of the edge event-triggered sampling strategies is illustrated by simulations.     

Decentralized dynamic event-triggered control for networked control systems under unreliable communication network and actuator saturation

In this paper, the stochastic stability of networked control systems (NCSs) with nonlinear perturbation and parameter uncertainties is studied. A decentralized dynamic event triggering scheme (DDETS) is introduced to reduce energy consumption and network transmission burden. Each channel can decide whether to transmit signals sampled by corresponding sensors through this mechanism. Due to the unreliability of communication network, a new mathematical model of NCSs based on multi-channel fading and hybrid cyber attacks is established, and the actuator is constrained by saturation. A sufficient condition for stochastic stability based on static controller is derived through Lyapunov stability theory, and two numerical examples are given to demonstrate the effectiveness of the method.     

动态事件触发机制下二阶多智能体系统完全分布式控制

本文研究了无向通信拓扑下二阶多智能体系统的一致性问题, 分别针对有领导者和无领导者的情形, 设计 了一类基于辅助动态变量的完全分布式事件触发控制策略, 该策略具有参数较少且易调等特点. 智能体自身的触 发函数满足条件时才向邻居广播自身的状态信息, 有效避免了连续通信, 减少了系统能量耗散. 每个智能体的控制 协议和触发函数都只用到自身的状态和邻居触发时刻的状态, 不涉及邻居的实时状态信息, 也不依赖通信拓扑网络 的任何全局信息. 利用代数图论以及Lyapunov稳定性理论, 证明在所提出的控制策略下, 二阶多智能体系统能够实 现渐近一致性, 且不存在Zeno行为. 仿真示例进一步验证了理论结果的有效性.     

基于事件触发的非线性多智能体系统的固定时间分群一致性

结合事件触发控制方法研究非线性多智能体系统的固定时间分群一致性问题.提出一种非线性分布式事件触发分群一致性控制协议,并给出状态信息触发控制器更新的条件.该控制协议不受入度平衡条件限制,且只需自身状态信息与邻居智能体进行通信即可在固定时间内快速实现分群一致性.系统收敛时间与智能体的初始状态无关,可有效降低系统控制器更新频率和系统的资源消耗.结合代数图论、矩阵分析及Lyapunov稳定性理论,证明在所提出协议作用下,多智能体系统在固定时间内能够实现分群一致性,且不存在Zeno行为.最后,通过仿真实例检验了理论结果的可行性.     

基于事件触发的时变拓扑多智能体系统编队控制

针对资源受限的时变拓扑多智能体系统的编队控制问题,提出一种基于复合误差信息事件触发机制以减少不必要的信息传输,降低带宽占用,并设计了多智能体系统的编队控制协议和分布式事件触发机制.通过将多智能体系统的编队控制问题转化为闭环延时系统的稳定性问题,构造Lyapunov-Krasovskii函数并利用线性矩阵不等式技术,给出多智能体系统实现编队的充分条件.最后,通过仿真验证了所提出方法的有效性.     

Decentralized control scheme for adaptive earthworm locomotion using continuum-model-based analysis

Crawling locomotion has been the focus of attention in the field of robotics because various applications of it are expected. However, the design methodologies for crawling robots, which can be applied in various environments, are not yet established. Therefore, we considered an earthworm as our model and employed an unconventional approach: we analyzed the motion of the earthworm with a continuum model and derived an optimal force distribution for its efficient propulsion, based on which we proposed an autonomous decentralized control scheme. The validity of the proposed control scheme was confirmed via simulations.     

Optimal control strategy by tracking and compensation for ICPS under the DoS attack

To solve the security problem of industrial cyber-physical systems (ICPS) suffering from the Denial of Service (DoS) attack, this paper proposes an optimal control strategy with functions of tracking and compensation control. The system model, being depicted as a discrete linear time-invariant system combined with an improved Bernoulli model, is established to describe the system under DoS attacks by using the feedback control theory. The optimal control strategy is completed by designing linear quadratic Gaussian (LQG) controller consisting of a tracking regulator and a Kalman filter to achieve tracking control of ICPS whose equilibrium state is neither zero state nor zero output, where a periodic event-triggered mechanism is adopted for ensuring the system's stability. The compensation control strategy is completed by designing a compensator to compensate the system to a certain extent through the multistep state prediction compensation strategy after a DoS attack being detected, where the ${\chi }^2$ detector is adopted to detect the DoS attack based on the measurement residual obtained by the Kalman filter. The simulation test is conducted by using Simulink/True Time tool with a ball-beam system as the physical object, whose results show that the tracking regulator can achieve the tracking control of ICPS; compensation strategy can reduce the impact of the attack on the system to a certain extent.     

A low-cost communication security scheme of UAV based on multi-round reverse auction model

In recent years, the security of wireless communication has received more and more attention. However, with the increasing requirements for security performance in the process of wireless communication, the cost of improving security also increases. Therefore, how to improve the security of wireless communication while reducing costs has become a serious challenge. Aiming at the security problems in the UAV-assisted wireless communication link based on the premise of low cost and high profit, this paper studies how to motivate non-offloading users to send jamming power to interfere with eavesdropping UAVs, so efficiently and economically to improve the security performance of wireless communication link. Firstly, the relationship between the security performance of the communication link and the interference power is revealed through the theoretical model. Then, we propose a scenario consisting of a legitimate UAV, a ground user group, and an eavesdrop UAV. In this scenario, we divide the ground users into offloading users and non-offloading users. At the same time, the cost functions for offloading users and utility functions for non-offloading users are defined, and non-offloading users are encouraged to help to offload users unload data safely to a legitimate UAV by obtaining rewards for offloading users. Considering the selfishness of users, a reverse auction algorithm based on multi-user groups is proposed to achieve the optimal mapping between non-offloading users and offloading users. Finally, the effectiveness of the proposed scheme is verified by a large number of simulations. The research results show that the scheme innovative designs a method for users to cooperate to interfere with eavesdroppers, which can reduce costs and improve utility while maximizing the improvement of wireless communication link security.     

PDE-based event-triggered containment control of multi-agent systems with input delay under spatial boundary communication

This article studies the containment control problem for multi-agent systems with input delay under spatial boundary communication by employing an event-based approach. Firstly, the collective dynamics of multi-agent systems are described as parabolic partial differential equations (PDEs). Applying the integral transformation method developed in PDEs, the delayed parabolic PDEs are transformed into a series of new coupled PDE-PDE systems. Then, by taking the spatial boundary communication scheme into account and using the local boundary information, two boundary containment control protocols together with a dynamic event-triggered scheme (DETS) are designed, such that the states of all followers converge to a convex hull formed by multiple leader agents with and without input delay. The optimal protocols are given by minimizing the 2-norm of the designed control gain matrix, and the exclusion of the Zeno behavior is analyzed. Finally, a numerical simulation example is provided to support the main results.