Cyber-Physical Codesign of Wireless Structural Control System

Structural control systems play a critical role in protecting civil infrastructure from natural hazards such as earthquakes and extreme winds. Utilizing wireless sensors for sensing, communication and control, wireless structural control systems provide an attractive alternative for structural vibration mitigation. Although wireless control systems have advantages of flexible installation, rapid deployment and low maintenance cost, there are unique challenges associated with them, such as wireless network induced time delay and potential data loss. These challenges need to be considered jointly from both the network (cyber) and control (physical) perspectives. This research aims to develop a framework facilitating cyber-physical codesign of wireless control system. The challenges of wireless structural control are addressed through: (1) a numerical simulation tool to realistically model the complexities of wireless structural control systems, (2) a codesign approach for designing wireless control system, (3) a sensor platform to experimentally evaluate wireless control performance, (4) an estimation method to compensate for the data loss and sensor failure, and (5) a framework for fault tolerance study of wireless control system withreal-time hybrid simulation. The results of this work not only provide codesign tools to evaluate and validate wireless control design, but also the codesign strategies to implement on real-world structures for wireless structural control

Holistic Control for Cyber-Physical Systems

The Industrial Internet of Things (IIoT) are transforming industries through emerging technologies such as wireless networks, edge computing, and machine learning. However, IIoT technologies are not ready for control systems for industrial automation that demands control performance of physical processes, resiliency to both cyber and physical disturbances, and energy efficiency. To meet the challenges of IIoT-driven control, we propose holistic control as a cyber-physical system (CPS) approach to next-generation industrial automation systems. In contrast to traditional industrial automation systems where computing, communication, and control are managed in isolation, holistic control orchestrates the management of cyber platforms (networks and computing platforms) and physical plant control at run-time in an integrated architecture. Specifically, this dissertation research comprises the following primary components. Holistic wireless control: The core of holistic wireless control is a holistic controller comprising a plant controller and a network controller cooperating with each other. At run-time the holistic controller generates (1) control commands to the physical plant and (2) network reconfiguration commands to wireless networks based on both physical and network states. This part of dissertation research focused on the design and evaluation of holistic controllers exploiting a range of network reconfiguration strategies: (1) adapting transmission redundancy, (2) adapting sampling rates, (3) self-triggered control, and (4) dynamic transmission scheduling. Furthermore, we develop novel network reconfiguration protocols (NRP) as actuators to control network configurations in holistic control. Holistic edge control: This part of dissertation research explores edge computing as a multitier computing platform for holistic control. The proposed switching multi-tier control (SMC) dynamically switches controllers located on different computation platforms, thereby exploiting the trade-off between computation and communication in a multi-tier computing platform. We also design the stability switch between local and edge controllers under information loss from another perspective, based on co-design of edge and local controllers that are designed via a joint Lyapunov function. Real-time wireless cyber-physical simulators: To evaluate holistic control, we extend the Wireless Cyber-Physical Simulator (WCPS) to integrate simulated physical plants (in Simulink) with real wireless networks (WCPS-RT) and edge computing platforms (WCPS-EC). The real-time WCPS provides a holistic environment for CPS simulations that incorporate wireless dynamics that are challenging to simulate accurately, explore the impacts and trade-off of computation and communication of multi-tier platforms, and leverage simulation support for controllers and plants

Trustworthiness in Mobile Cyber Physical Systems

Computing and communication capabilities are increasingly embedded in diverse objects and structures in the physical environment. They will link the ‘cyberworld’ of computing and communications with the physical world. These applications are called cyber physical systems (CPS). Obviously, the increased involvement of real-world entities leads to a greater demand for trustworthy systems. Hence, we use "system trustworthiness" here, which can guarantee continuous service in the presence of internal errors or external attacks. Mobile CPS (MCPS) is a prominent subcategory of CPS in which the physical component has no permanent location. Mobile Internet devices already provide ubiquitous platforms for building novel MCPS applications. The objective of this Special Issue is to contribute to research in modern/future trustworthy MCPS, including design, modeling, simulation, dependability, and so on. It is imperative to address the issues which are critical to their mobility, report significant advances in the underlying science, and discuss the challenges of development and implementation in various applications of MCPS

NASA Tech Briefs, May 1992

Topics include: New Product Ideas; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery; Fabrication Technology; Mathematics and Information Sciences; Life Sciences