Cyber-Physical Systems (CPS) focus on the combination and coordination of computational and physical resources. The goal is to offer autonomy, adaptability, and improve efficiency beyond current embedded computing systems. These networked systems are in a variety of fields including aerospace, transportation, energy, manufacturing, and civil infrastructure. As a result, many of the techniques and hardware developed are cross-disciplinary, but an understanding of the physical system of interest, i.e. bridges or buildings, is essential. The group works in three main areas required for CPS:

• Algorithms and techniques to integrate cyber and civil infrastructure
• Hardware development tailored to these civil systems
• Analysis tools to evaluate performance

Structural control offers an alternative approach to structural modification to limit building response under dynamic loads, such as wind or earthquakes. Structural control systems limit the vibration response through altering mass, stiffness, or introducing counter forces by adding a supplemental damping device. This group focuses on active, hybrid, or semi-active systems, which impart forces based on measurement feedback. 

Modern control systems often use a centralized feedback design, which is sensitive to controller failure. Decentralized control schemes offer an approach robust to sensor or controller failure. In decentralized control architectures, there is often little or no knowledge sharing among local controllers. These decentralized control strategies offer several advantages for wireless structural control: limiting communication and associated delays, leverage onboard processing power, and add robustness to the control system.

Wireless smart sensors combine communication, processing, memory and sensing capabilities on one platform. Smart sensors are popular for structural health monitoring (SHM) due to their lower cost and ease of implementation. As such, hardware and software development has been tailored to SHM. Recently, the applications of wireless sensor networks have expanded to include wireless control. 

This group currently focuses on the Imote2 Smart Sensor Platform, which offers a variable speed processor and  a flexible sensor interface. Previous sensor hardware developed for the Imote2 was tailored to SHM applications and, as a result, the data acquisition architecture introduces significant latency. Data acquisition and actuation hardware have been developed for control applications that limits latency due to the hardware. The SHM-SAR and SHM-D2A (pictured below) can stack with the Imote2 to offer a complete control loop on an individual sensor node. The wireless control software developed builds on the ISHMP Toolsuite, which uses a modular service-oriented architecture that can easily be tailored to new applications.