CAREER: A Compositional Approach to Modular Cyber-Physical Control System Design

复杂的、网络化的、分布式的网络物理系统(CPSS)正出现在航空航天、汽车等安全关键应用领域。这种系统的设计在很大程度上依赖于工程师的洞察力和经验，因为缺乏能够处理这些系统的复杂性的原则性设计方法。因此，需要进行广泛的测试和微调，以确保最终产品满足设计目标。作为一种原则性的替代方案，该项目建议在网络物理系统的设计和生命周期中使用模块化来管理复杂性。其目的是为设计模块化的计算机物理控制系统开发科学基础和相关的算法工具。如果成功，从长远来看，这项研究将导致在自动化设计工具的支持下，为CPSS提供“即插即用”的集成框架，用户可以用一个子系统替换另一个子系统或对子系统进行升级，同时保持操作的正确性保证。这项研究的结果将与许多应用领域相关，包括下一代飞行器、汽车系统和机器人。其潜在的变革性影响将是这些领域国家方案的设计和运作方式。向经济的转化将通过积极寻找和接触行业合作伙伴来进行。这项研究工作将得到一个教育计划的补充，该计划将在本科生和研究生中培养CPS领域的跨学科研究和思维，以培养下一代CPS研究人员和实践者。具体地说，该项目将开发理论基础和相关的算法工具，用于分布式综合可证明是正确的控制协议，从而产生网络物理控制系统的组合设计原则。特别是，将开发离散/逻辑级别的系统要求分解和连续/系统级别的系统状态分解的算法。其主要思想是在影响每个子系统的外部和内部因素之间进行新颖的分离，从而允许显式地计算子系统成功运行所需的内部交互作用。这些内部交互，即接口规则，根据假设和保证对来捕获，这些假设和保证对用于解决局部综合问题，以分布式方式获得局部控制器，同时保持这些控制器同时部署时的全局正确性保证。通过在这些接口规则上引入适当的偏序，并根据这些顺序关系调整接口规则的复杂性，将探索模块化与性能的权衡空间。来自控制理论(分散和鲁棒控制、模型降阶、离散事件系统)和形式化方法(时序逻辑、成分验证、分布式反应综合)的工具将用于解决这些问题。

Complex, networked, distributed cyber-physical systems (CPSs) are emerging in many safety-critical application domains such as aerospace and automotive. Design of such systems heavily relies on insights and experiences of engineers as principled design methodologies that can cope with the complexity of these systems are lacking. As a result, extensive testing and fine-tuning is required to ensure that the final product satisfies the design objectives. As a principled alternative, this project proposes to use modularity for managing complexity during both the design- and the life-cycles of cyber-physical systems. The objective is to develop the scientific foundation and associated algorithmic tools for the design of modular cyber-physical control systems. If successful, in the long-run this research will lead to a "plug and play" integration framework for CPSs supported by automated design tools, where one can replace a subsystem with another one or perform upgrades to subsystems while maintaining operational correctness guarantees. Results from this research will be relevant to many application domains, including next generation air vehicles, automotive systems and robotics. Its potential transformative impact will be on the way CPSs in these domains are designed and operated. Translation to the economy will proceed by actively seeking and engaging industrial partners. This research effort will be complemented by an education plan where interdisciplinary research and thinking in the area of CPS will be fostered among undergraduate and graduate students to prepare the next generation of CPS researchers and practitioners.To be specific, the project will develop theoretical foundations and associated algorithmic tools for distributed synthesis of provably correct control protocols that give rise to compositional design principles for cyber-physical control systems. In particular, algorithms for decompositions of system requirements at the discrete/logic level and of the system states at the continuous/system level will be developed. The main idea is a novel separation between external and internal factors affecting each subsystem that allows internal interactions required for the successful operation of a subsystem to be computed explicitly. These internal interactions, namely interface rules, are captured in terms of assumption and guarantee pairs that are used for solving local synthesis problems to obtain local controllers in a distributed manner, while maintaining global correctness guarantees when these controllers are deployed simultaneously. The modularity-performance trade-off space will be explored by introducing proper partial orders on these interface rules and by tuning the complexity of the interface rules according to these order relations. Tools from control theory (decentralized and robust control, model reduction, discrete event systems) and formal methods (temporal logics, compositional verification, distributed reactive synthesis) will be brought to bear to address these problems.