To adapt to the uncertain environment smartly and timely, cyber physical systems (CPSs) have to interact with the physical world in a decentralized but rigorous, organized way. Guaranteeing the timing reliability is key to achieve consensus on the order of distributed events, as well as dependable cooperative decision processing. Based on our hierarchically decentralized compositional self-adaptive framework, we propose a formal compositional reliability-contract-based solution to guarantee the timing reliability of event observation and decision processing in a large-scale, geographically distributed CPS. As the prophetic decision may not fit the local situation well because of the uncertainties, we propose a gradual contract optimization solution to refine the dependability, timeliness, and energy consumption. Following the seven proposed composition schemes, we employ the nondominated sorting genetic algorithm II (NSGA-II) algorithm to optimize arrangement of decision. Moreover, a topology-aware time reserving solution is applied to improve the resilience of processing time and to tolerance timing failures. Both simulation results and real-world testing are introduced to evaluate the efficacy of our proposal. We believe that the formal compositional contract will be a competitive CPS solution to analyze requirements and optimize the self-adaptation decision at runtime.

中文翻译：

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用形式组合契约提高自适应信息物理系统的可靠性

为了巧妙及时地适应不确定的环境，网络物理系统 (CPS) 必须以分散但严谨、有组织的方式与物理世界交互。保证时序可靠性是达成分布式事件顺序共识的关键，也是可靠的协同决策处理的关键。基于我们的分层分散的组合自适应框架，我们提出了一个正式的基于组合可靠性契约的解决方案，以保证大规模、地理分布的 CPS 中事件观察和决策处理的时间可靠性。由于不确定性，预测性决策可能无法很好地适应当地情况，因此我们提出了渐进式合约优化方案，以完善可靠性、时效性和能耗。根据提出的七种组合方案，我们采用非支配排序遗传算法 II (NSGA-II) 算法来优化决策安排。此外，应用拓扑感知时间预留解决方案来提高处理时间的弹性和容错计时故障。引入了模拟结果和实际测试来评估我们建议的有效性。我们相信正式的组合合约将是一个有竞争力的 CPS 解决方案，用于分析需求并优化运行时的自适应决策。引入了模拟结果和实际测试来评估我们建议的有效性。我们相信正式的组合合约将是一个有竞争力的 CPS 解决方案，用于分析需求并优化运行时的自适应决策。引入了模拟结果和实际测试来评估我们建议的有效性。我们相信正式的组合合约将是一个有竞争力的 CPS 解决方案，用于分析需求并优化运行时的自适应决策。