论文标题
基于计时的框架,用于在安全限制下设计弹性的网络物理系统
A Timing-Based Framework for Designing Resilient Cyber-Physical Systems under Safety Constraint
论文作者
论文摘要
需要网络物理系统(CPS)来满足各种应用领域的安全限制,例如机器人技术,工业制造系统和电力系统。已经显示出故障和网络攻击会导致安全违规,这可能会损害系统并危害人类生命。已经提出了弹性体系结构,以确保CP在此类故障和攻击中的安全性,包括冗余和从安全的操作条件中重新启动。现有的CPS弹性体系结构利用不同的机制来确保安全性,目前尚无对它们进行比较的方法。此外,用于使用一种体系结构的CPS进行的分析和设计不容易扩展到另一种体系结构。在本文中,我们提出了一个基于计时的框架,用于采用各种弹性架构,并开发一种通用方法来安全分析和计算控制策略和设计参数。利用网络子系统在有限数量的状态中运行的洞察力,我们首先开发了一种混合系统模型,该模型捕获了采用这些架构中任何一个的CPS。基于混合系统,我们制定了控制策略的联合计算和CPS相关的时序参数的问题,以满足给定的安全限制并为解决方案提供足够的条件。利用派生条件,我们提供了一种算法来计算与就业体系结构相关的控制策略和正时参数。我们还注意到,我们的解决方案可以应用于具有多项式动力学的宽类CP,并且还允许合并新的体系结构。我们通过对车辆的自适应巡航控制进行案例研究来验证我们的拟议框架。
Cyber-physical systems (CPS) are required to satisfy safety constraints in various application domains such as robotics, industrial manufacturing systems, and power systems. Faults and cyber attacks have been shown to cause safety violations, which can damage the system and endanger human lives. Resilient architectures have been proposed to ensure safety of CPS under such faults and attacks via methodologies including redundancy and restarting from safe operating conditions. The existing resilient architectures for CPS utilize different mechanisms to guarantee safety, and currently there is no approach to compare them. Moreover, the analysis and design undertaken for CPS employing one architecture is not readily extendable to another. In this paper, we propose a timing-based framework for CPS employing various resilient architectures and develop a common methodology for safety analysis and computation of control policies and design parameters. Using the insight that the cyber subsystem operates in one out of a finite number of statuses, we first develop a hybrid system model that captures CPS adopting any of these architectures. Based on the hybrid system, we formulate the problem of joint computation of control policies and associated timing parameters for CPS to satisfy a given safety constraint and derive sufficient conditions for the solution. Utilizing the derived conditions, we provide an algorithm to compute control policies and timing parameters relevant to the employed architecture. We also note that our solution can be applied to a wide class of CPS with polynomial dynamics and also allows incorporation of new architectures. We verify our proposed framework by performing a case study on adaptive cruise control of vehicles.