集中式超大规模储能电站信息物理系统建模与可靠性评估

集中式超大规模储能电站与其控制系统逐渐发展成为信息物理系统(cyber physical system, CPS),信息技术和监控系统能够使超大规模储能电站应对多样化场景和满足不同的需求,但也带来一定程度的安全运行风险,因此对其进行可靠性建模和分析具有非常重要的意义.首先,建立超大规模储能电站的CPS模型,并分析物理侧与信息侧的交互影响;其次,对信息系统中多种信息扰动的可靠性状态进行建模分析,并提出储能电站CPS可靠性评估指标;然后,分别采用非序贯和序贯蒙特卡洛方法对超大规模储能电站的信息层和物理层元件进行抽样,并量化分析多信息扰动因素对超大规模储能电站CPS可靠性的影响;最后,通过算例仿真结果验证所提模型和方法的有效性,结果表明所提模型可为超大规模储能电站规划和运行提供有效技术支撑.     

信息物理系统在变压器稳压调节控制中的应用研究

考虑到现有变压器电压调节方法受调压档位限制,且电压调整判断依据为调度部门确定的电压曲线,难以实现灵活、高效、高精度的变压器输出电压稳定调节,提出一种基于信息物理融合系统的稳压动态调节方法以更好地解决变压器运行过程中出现的电压偏移问题。建立变压器的物理模型与信息模型,通过物理参数与信息属性的相互映射,利用动态链接对物理模型与信息模型在统一仿真平台上进行整合,建立变压器的信息物理融合系统模型,通过信息量对物理量的实时反馈作用机制,控制变压器原副线圈匝数比的自动调节,实现变压器输出稳压。仿真实验结果表明信息物理融合方法在变压器输出电压稳定调节应用中具有一定的有效性。     

基于XML的信息物理融合系统组件建模与仿真

信息物理融合系统（CPS）涉及多种计算模型的集成和协同工作，针对CPS设计方法不统一、重塑性差、复杂度高、难以协同建模验证等问题，提出一种结构化、可描述行为的异元组件模型。首先，用统一组件建模方法进行建模，解决模型不开放问题；然后，用可扩展标记语言（XML）规范描述各类组件，解决不同计算模型描述语言不一致和不可扩展问题；最后，用多级开放组件模型的协同仿真验证方式进行仿真验证，解决验证的不可协同问题。通过通用组件建模方法、XML组件规范描述语言以及验证工具平台XModel对医用恒温箱进行了建模、描述和仿真。医用恒温箱的案例表明，这种模型驱动建立可重塑异元组件并确认其设计正确性的过程，支持信息物理协同设计和边构建边纠正，可避免在系统实现过程中发现问题时再进行反复修改。     

信息物理系统下的耦合映射跟驰模型

针对车辆跟驰模型中信息响应延迟时间导致交通拥堵,通过信息物理系统对耦合映射跟驰模型重新定义,在嵌入计算功能的网络端与延迟导致拥堵的物理端相互作用下,提出均衡车头距的概念,在此基础上量化跟驰过程中的响应延迟时间,从而间接增大了车头距,拉长可操作时间线,给驾驶系统提供预估功能。考虑前车、后车对己车的反馈控制,并选取不同的反馈系数,仿真结果表明CPS定义下的耦合映射跟驰模型,对交通拥堵具有明显的抑制效果。     

离散事件系统框架下信息物理系统攻击问题综述

信息物理系统(cyber physical system, CPS)由受控对象、传感器、执行器、监控器和通信网络组成,通信网络的使用增加了信息物理系统面临外部攻击的风险.鉴于此,综述基于离散事件系统框架处理信息物理系统攻击问题的相关研究工作.首先对信息物理系统进行简要介绍;然后对信息物理系统中的攻击进行分类;最后重点阐述信息物理系统中攻击策略的设计、攻击的检测与防御以及攻击鲁棒性监控器设计的研究现状.     

Special issue on cyber physical systems

This special issue is devoted to recent research findings in the field of Cyber Physical Systems. The special issue follows “The IEEE 26th International Conference on Advanced Information Networking and Applications (AINA-2012)”, held at the Fukuoka Institute of Technology, Fukuoka, Japan, March 26–29, 2012.     

Fuzzy harmony search based optimal control strategy for wireless cyber physical system with industry 4.0

Journal of Intelligent Manufacturing - Recently, Industry 4.0 facilitates implementing several modular smart factories particularly the Cyber-Physical System. Due to enhanced growth in the...     

A Fog-Cloud based cyber physical system for Ulcerative Colitis diagnosis and stage classification and management

Ulcerative Colitis is a fairly common, chronic or long-term disease that causes inflammation of the large intestine. It can be debilitating and can sometimes lead to life threatening complications. Therefore, its diagnosis in nascent stages is important. Healthcare services based on Fog-Cloud assisted Cyber-Physical Systems are emerging as a proactive and efficacious solution to provide remote monitoring of individuals for early detection and consequent management of several diseases. This paper presents a novel IoT-Fog-Cloud assisted Cyber Physical System for diagnosis and stage classification of Ulcerative Colitis using Naïve Bayes classifier and Deep Neural Network respectively. A vital point of this paper is real-time alert generation from Fog Layer in case the user need emergency treatment if he/she is already diagnosed with UC. Finally, analysis results and compiled medical information of each user is stored on cloud. Implementation results of the proposed framework proves its efficiency in diagnosis and subsequent stage classification of Ulcerative Colitis with real-time classification mechanism at fog layer. Furthermore, alert generation improves the efficacy of the proposed system.     

基于Markov模型的系统安全性和可靠性分析

建立了二乘二取二系统状态转换的Markov模型,研究了失效率、维修系数、故障检测覆盖率等参数对二乘二取二系统的安全性、可靠性和可用性的影响,证明分布式二乘二取二系统具有更高的可靠性、安全性。     

Physical layer authentication for automotive cyber physical systems based on modified HB protocol

Automotive cyber physical systems (CPSs) are ever more utilizing wireless technology for V2X communication as a potential way out for challenges regarding collision detection, wire strap up troubles and collision avoidance. However, security is constrained as a result of the energy and performance limitations of modern wireless systems. Accordingly, the need for efficient secret key generation and management mechanism for secured communication among computationally weak wireless devices has motivated the introduction of new authentication protocols. Recently, there has been a great interest in physical layer based secret key generation schemes by utilizing channel reciprocity. Consequently, it is observed that the sequence generated by two communicating parties contain mismatched bits which need to be reconciled by exchanging information over a public channel. This can be an immense security threat as it may let an adversary attain and recover segments of the key in known channel conditions. We proposed Hopper-Blum based physical layer (HB-PL) authentication scheme in which an enhanced physical layer key generation method integrates the Hopper-Blum (HB) authentication protocol. The information collected from the shared channel is used as secret keys for the HB protocol and the mismatched bits are used as the induced noise for learning parity with noise (LPN) problem. The proposed scheme aims to provide a way out for bit reconciliation process without leakage of information over a public channel. Moreover, HB protocol is computationally efficient and simple which helps to reduce the number of exchange messages during the authentication process. We have performed several experiments which show that our proposed design can generate secret keys with improved security strength and high performance in comparison to the current authentication techniques. Our scheme requires less than 55 exchange messages to achieve more than 95% of correct authentication.     

选煤厂信息物理系统任务调度研究

建立了选煤厂信息物理系统模型,将动态联盟思想引入选煤厂信息物理系统任务调度中,并提出了一种基于改进离散粒子群优化算法的选煤厂信息物理系统任务调度算法。该算法首先采用离散粒子群优化算法进行全局寻优,然后采用禁忌搜索算法进行局部搜索,求得全局最优解。仿真结果表明,该算法提高了任务调度的收敛速度、精度以及处理器的平均利用率。     

QoS guaranteeing robust scheduling in attack resilient cloud integrated cyber physical system

In this paper, we propose a security framework based on the semi-network form game in unison with a robust and attack resilient scheduling mechanism for a cloud integrated Cyber Physical System (CPS). As CPS moves from the traditional Sensing Control and Data Acquisition (SCADA) systems with limited on-board processing units, the need to use cloud computing arises owing to the ever increasing processing demands of heterogeneous CPS applications. In such systems, system stability and critical operational capability have the highest priority. This multi-system coupling can have security vulnerabilities which can cripple the speed and effectiveness of data processing, which is unacceptable in time and resource critical CPS applications owing to the need for satisfying the stringent Quality of Service (QoS) requirements. Therefore, a robust scheduling mechanism invulnerable to security attacks is needed to efficiently utilize the scalable processing components as provided by a cloud computing platform. However, scalability brought in by the cloud integration and data migration increases the attack space of an attacker due to an increase in available access points. To address this issue, we developed a new method of learning procedure using Bayesian Networks for the semi-network form game to aid our scheduling algorithm. We employ game theoretic principles to proactively understand the behavior of an attacker based on the strategic decisions made by the defender. This helps us in building a robust scheduling mechanism that schedules tasks based on the decisions made from the output of the game.     

基于LabVIEW的虚拟仪器技术在结构健康监测中的应用

基于虚拟仪器技术构建新的结构健康监测系统,介绍了利用LabVIEW图形化编程语言开发设计结构健康监测系统的设计思想、结构组成、实现方法和功能.与传统结构健康监测系统相比,基于虚拟仪器的结构健康监测系统,具有可操作性强、通用性好、性价比高、功能强大、快捷方便等特点.并且能够实现数据的自动采集和在线实时监测,可以对数据进行多种方式的分析和处理,在工程实际中具有广阔的应用前景.     

Structural reliability assessment based on directional vector approximation method

A new numerical integration method for calculating structural failure probabilities based on a directional vector approximation is proposed. The approach is based on a division method of the surface of the unit hypersphere, in which the directional vectors are determined by relating to the finite element meshes allocated on the surface of the unit hypersphere. The failure probability is calculated by using the values of area of the finite element meshes and the upper probabilities of the chi square distribution. Numerical examples are provided to show the validity of the proposed method, which gives efficiently good approximate values of structural failure probabilities.     

工业信息物理系统的攻击建模研究

无线通信网络的脆弱性使得工业信息物理系统易遭受各类网络攻击.为了更深入地了解不同网络攻击的特征进而建立有效的防御措施,构建一种线性时不变离散系统的工业信息物理系统结构;深入研究信息物理系统攻击者攻击空间及攻击者攻击模型,采用控制理论方法研究攻击空间模型的模型知识、披露资源和破坏资源的数学表达;对拒绝服务攻击、重放攻击、虚假数据注入攻击3种典型网络攻击的基本特性,以及对应攻击下攻击模型的表现形式进行分析.通过Simulink/Truetime仿真工具对破坏性和隐蔽性性能进行仿真实验.结果表明,所研究的攻击空间模型及攻击者攻击模型能够有效地描述网络攻击的攻击特性.     

Structural health monitoring system based on multi-agent coordination and fusion for large structure

In practical applications of structural health monitoring technology, a large number of distributed sensors are usually adopted to monitor the big dimension structures and different kinds of damage. The monitored structures are usually divided into different sub-structures and monitored by different sensor sets. Under this situation, how to manage the distributed sensor set and fuse different methods to obtain a fast and accurate evaluation result is an important problem to be addressed deeply. In the paper, a multi-agent fusion and coordination system is presented to deal with the damage identification for the strain distribution and joint failure in the large structure. Firstly, the monitoring system is adopted to distributedly monitor two kinds of damages, and it self-judges whether the static load happens in the monitored sub-region, and focuses on the static load on the sub-region boundary to obtain the sensor network information with blackboard model. Then, the improved contract net protocol is used to dynamically distribute the damage evaluation module for monitoring two kinds of damage uninterruptedly. Lastly, a reliable assessment for the whole structure is given by combing various heterogeneous classifiers strengths with voting-based fusion. The proposed multi-agent system is illustrated through a large aerospace aluminum plate structure experiment. The result shows that the method can significantly improve the monitoring performance for the large-scale structure.     

欺骗攻击环境下具有执行器故障的跳变耦合信息物理系统的同步控制

针对一类离散Markov跳变耦合信息物理系统(CPS)的同步控制问题,在考虑系统参数跳变、耦合参数跳变、控制信息不完全和人为攻击的情况下,设计同步控制器实现CPS的同步.首先,给出具有随机欺骗攻击和执行器故障的Markov跳变耦合CPS模型.其次,基于矩阵Kronecker积,得到同步误差系统,将CPS的同步控制问题转化为同步误差系统的稳定性分析问题.再次,通过构造合适的Lyapunov-Krasovskii泛函,并利用Lyapunov稳定性理论和线性矩阵不等式方法得到使同步误差系统稳定的充分条件,在此基础上,设计同步控制器实现对Markov跳变耦合CPS的同步控制.最后,通过数值仿真例子说明该同步控制器设计方法的有效性.