Alexander Chernoguzov

Robust architectures for embedded wireless network control and actuation

Networked cyber-physical systems are fundamentally constrained by the tight coupling and closed-loop control of physical processes. To address actuation in such closed-loop wireless control systems there is a strong need to rethink the communication architectures and protocols for reliability, coordination, and control. We introduce the Embedded Virtual Machine (EVM), a programming abstraction where controller tasks with their control and timing properties are maintained across physical node boundaries and functionality is capable of migrating to the most competent set of physical controllers. In the context of process and discrete control, an EVM is the distributed runtime system that dynamically selects primary-backup sets of controllers given spatial and temporal constraints of the underlying wireless network. EVM-based algorithms allow network control algorithms to operate seamlessly over less reliable wireless networks with topological changes. They introduce new capabilities such as predictable outcomes during sensor/actuator failure, adaptation to mode changes, and runtime optimization of resource consumption. An automated design flow from Simulink to platform-independent domain-specific languages, and subsequently, to platform-dependent code generation is presented. Through case studies in discrete and process control we demonstrate the capabilities of EVM-based wireless network control systems.

Performance analysis of AADL models using real-time calculus

Architecture Analysis and Design Language (AADL) captures both platform and software architectures of embedded systems in a component-oriented fashion. Properties embedded in an AADL model enable several high-level analysis techniques. In this work, we explore how to perform analysis of end-to-end timing characteristics of an AADL model using Real-Time Calculus (RTC). We identify properties of AADL models that are necessary to enable such analysis and develop an algorithm to transform an AADL model into an RTC model. We use the proposed technique to identify analyze the infrastructure for sensor network architecture.

Next-Generation Access Control for Distributed Control Systems

With the rapid integration of wired and wireless internetworking technologies, distributed control systems (DCS) are increasingly susceptible to cyberattacks. A well-designed access control framework could potentially contain and mitigate the impact of cyberattacks. However, existing solutions often fail to cover and protect all connected devices, leaving holes that are sufficient to undermine the security and safety of a plant. Further, in current DCS environments, its hard to adhere to the least-privilege principle because access control policies are distributed among many heterogeneous systems. In this article, the authors identify key challenges in moving toward a more complete and manageable access control framework for DCS, and present a model architecture that can be adapted by the industrial control system community to ensure that every access is checked against policies that adhere to the least-privilege principle. Their proposed architecture facilitates centralized (plant-wide) policy management and protection of every connected field device.