Chemical and Biomolecular Engineering

Joseph K. Scott, Ph.D.

 

 

Joseph K. Scott

Assistant Professor
Process Systems Engineering, Renewable Energy Systems, Dynamic Simulation and Optimization, Global Optimization, Fault Detection and Fault-Tolerant Control
Email: jks9@clemson.edu
Phone: 864-656-0997
Office:  207B Earle Hall

Education

Ph.D., Massachusetts Institute of Technology, 2012
M.S., Massachusetts Institute of Technology, 2008
B.S., Wayne State University, 2006

Research Interests

Professor Scott’s research group develops mathematical and algorithmic tools that support the design, operation, and control of complex chemical processes. Technological advances in areas from renewable energy to bioengineering and automation have led to a host of modern chemical processes characterized by (1) non-standard design/control specifications, including stringent safety and environmental considerations, robustness to uncertainty, and fault tolerance, and (2) the need for advanced modeling techniques incorporating features such as stochasticity, multiscale physics, and hybrid discrete-continuous dynamics. Although simulation techniques for these processes have advanced considerably in recent years, many design and control challenges posed by these processes remain beyond the state-of-the-art. In the Scott group, we draw from expertise in mathematical analysis, numerical simulation, dynamic systems theory, and optimization theory to develop new theoretical and computational techniques to address these challenges. Some specific areas of interest are described below.

Optimal Design and Operation of Renewable Energy Systems
The use of wind and solar resources for electrical power generation is severely limited by the intermittent and unpredictable nature of these resources. In order to reliably meet consumer demand using conventional generation and dispatching methods, these factors have forced utilities to use a mix of resources in which the combined wind and solar generation capacity is dominated by a large, controllable generation capacity based on fossil-fuels. Achieving a high percentage of wind and solar resources in this mix requires a different approach with two key ingredients: (1) the use of multiple renewable resources that are less variable in aggregate than individually, and (2) the use of multiple energy storage options to buffer both long and short-term variations.

The Scott group is undertaking research to develop effective algorithms for determining optimal designs and operational policies for these so-call hybrid renewable energy systems. Due to the variability of wind and solar resources, these systems must be evaluated using stochastic simulations. This severely limits the applicability of numerical optimization algorithms, and has led to the use of ad hoc randomized algorithms that are computationally intensive and provide only suboptimal solutions. Our research aims to develop efficient new optimization methods with performance guarantees for a class of stochastic models. Developments in this area have the potential to impact the design and operation of renewable energy system at all scales, and bear upon the overall cost effectiveness of such systems.

Fault Detection and Fault-Tolerant Control
Equipment failures and other abnormal events have become a significant source of economic loss and safety hazards in many industries (e.g., petrochemical, aerospace, power generation, etc.). This is especially true for processes with automated control systems and/or tightly interconnected components, where minor, localized faults (e.g., sensor and actuator failures) can quickly lead to severe faults throughout the system. The Scott group is undertaking research into automated methods for detecting and diagnosing faults in complex systems. We are also investigating fault-tolerant control systems that automatically react to faults in order to achieve the best possible operation given the circumstances. Our methods make use of dynamic models of various fault scenarios to achieve fast and accurate fault diagnosis through the design of optimal test settings for the manipulated variables. In addition to the expected economic benefits in the conventional chemical industries, improved fault detection and fault-tolerant control is also crucial for processes in remote locations, such as unmanned drilling operations, off-grid power generation, and various military applications.

Selected Publications

Scott, J.K., Findeisen, R., Braatz, R.D., and Raimondo, D.M., “Input Design for Guaranteed Fault Diagnosis Using Zonotopes,” Submitted (2013)

Stuber, M.D., Scott, J.K., and Barton, P.I., “Global Optimization of Implicit Functions,” Submitted (2013)

Scott, J.K., and Barton, P.I., “Bounds on the Reachable Sets of Nonlinear Control Systems,” Automatica, 49, 93-100 (2013)

Scott, J.K., Chachuat, B., and Barton, P.I., “Nonlinear Convex and Concave Relaxations for the Solutions of Parametric ODEs,” Optimal Control Applications and Methods, 34, 145-163 (2013)

Scott, J.K., and Barton, P.I., “Interval Bounds on the Solutions of Semi-Explicit Index-One DAEs. Part 1: Analysis & Part 2: Computation,” Numerische Mathematik, In Press (2013) (doi: 10.1007/s00211-013-0531-y)

Scott, J.K., and Barton, P.I., “Convex and Concave Relaxations for the Parametric Solutions of Semi-Explicit Index-One Differential-Algebraic Equations,” Journal of Optimization Theory and Applications, 156, 617-649 (2013)

Scott, J.K., Marseglia, G.R., Magni, L., Braatz, R.D., and Raimondo, D.M., “A Hybrid Stochastic-Deterministic Input Design Method for Active Fault Diagnosis,” Proceedings of the 52nd IEEE Conference on Decision and Control, Firenze, Italy (December 2013)

Raimondo, D.M., Marseglia, G.R., Braatz, R.D., and Scott, J.K., “Fault-Tolerant Model Predictive Control with Active Fault Isolation,” Proceedings of the 2nd International Conference on Control and Fault Tolerant Systems, Nice, France (October 2013)

Raimondo, D.M., Braatz, R.D., Scott, J.K., “Active Fault Diagnosis using Moving Horizon Input Design,” Proceedings of the 2013 European Control Conference, Zurich, Switzerland (July 2013)

Scott, J.K., Raimondo, D.M., Findeisen, R., and Braatz, R.D., “Design of Active Inputs for Set-Based Fault Diagnosis,” Proceedings of the 2013 American Control Conference, Washington D.C. (June 2013)

Scott, J.K., and Barton, P.I., “Improved Relaxations for the Parametric Solutions of ODEs using Differential Inequalities,” Journal of Global Optimization, In Press (2012) (doi: 10.1007/s10898-012-9909-0)

Scott, J.K., Stuber, M.D., and Barton, P.I., “Generalized McCormick Relaxations,” Journal of Global Optimization, 51, 569-606 (2011)

Scott, J.K. and Barton, P.I., “Convex Relaxations for Nonconvex Optimal Control Problems,” Proceedings of the 50th IEEE Conference on Decision and Control, Orlando, FL (December 2011)

Scott, J.K., and Barton, P.I., “Tight, Efficient Bounds on the Solutions of Chemical Kinetics Models,” Computers and Chemical Engineering, 34, 717-731 (2010)

Scott, J.K. and Barton, P.I., “Convex Enclosures for the Reachable Sets of Nonlinear Parametric Ordinary Differential Equations,” Proceedings of the 49th IEEE Conference on Decision and Control, Atlanta, GA (December 2010)