This is a CAREER grant to fund research and educational activities aimed at using wireless sensors and actuators to control industrial chemical processes.
Intellectual merit
Existing process control systems rely on sensors, actuators and controllers that are connected via dedicated, wired control networks to reliably achieve critical control objectives such as stability, robustness and set-point tracking. Recently, the convergence of innovations in actuator and sensor technologies, wireless communications and digital electronics has led to the availability of low-cost wireless sensors and actuators that can be easily deployed and interfaced with the existing control systems. Augmenting pre-existing process control systems with additional wireless sensor and actuator networks (WSANs) creates new opportunities for enhancing and expanding the capabilities of process control technology through high density sensing and actuation, as well as deployments in unsafe areas that may be impossible to instrument with wired approaches. The availability of more sensor data, more actuation capabilities and more intercommunication between plant units enables the attainment of goals that cannot be achieved with existing control systems including proactive fault-tolerance and real-time plant reconfiguration to accommodate market demand changes. These goals are aligned with the emerging paradigm in process control and operations dealing with the development of ?smart plant? solutions.
Realizing this potential requires handling the fundamental challenges that this new technology introduces from a control point of view. Low-cost WSANs are often resource constrained, with limited power, computation and communication capabilities, and may occasionally be unreliable due to interference in the field, device failure, or environmental impact. These two real-world limitations can significantly limit the performance and flexibility benefits of WSANs if not accounted for in the controller design framework. Motivated by this, the objective of the proposed research is to resolve the fundamental issues associated with the deployment of wireless sensor and actuator networks in chemical plants for the purpose of augmenting existing process control systems to improve closed-loop system performance.
To achieve this objective, a number of projects are planned, including: (1) the development of model-based control,1 estimation and scheduling strategies that achieve the desired closed-loop performance with optimal use of WSAN resources, (2) the development of robust control methods that handle communication disruptions and the unreliability of the wireless communication medium, (3) application of the networked control, estimation and scheduling methods to large-scale chemical plants and distributed fuel cell networks used in distributed energy generation, and (4) integration of the research results into education and outreach activities. In addition to the networked analysis and control methods, this research will provide a fundamental understanding of the capabilities and limitations of WSANs in augmenting process control systems, give insight into the tradeoffs that exist between control and communications, and address practical implementation issues for managing these tradeoffs.
Broader Impact
Augmenting existing process control systems with WSANs is an important step towards realizing the vision of a smart reconfigurable plant which utilizes advanced cyber-infrastructure and communication technologies to tightly integrate process control and operations with real-time process information. There is a wide range of industrial processes that could benefit including large-scale chemical plants and fuel cell networks where the deployment of WSANs has the potential to enhance and expand existing control technology. To transfer the results and insight of the research into the industrial sector, the PI plans to seek collaborations with industry, organize tutorials and workshops both at UC Davis and in the context of major control conferences, and develop user-friendly software that will facilitate the practical implementation of the developed methods.
A number of activities are planned to integrate the research with education, including incorporation of research results into undergraduate and graduate-level process control courses, writing the first research monograph on networked process control, undergraduate student participation in research in collaboration with the NSF- funded California Alliance for Minority Participation program at UC Davis, the development of a Process Control Breadboard system to facilitate curriculum integration as well as outreach to high-school and college students from under-represented groups.
