Tomas B. Co

Tomas B. Co


Associate Professor, Chemical Engineering

  • PhD, University of Massachusetts


I am interested in advanced control strategies and algorithms including the application of artificial intelligence to process control

Process Integrity

As systems undergo operational changes due to equipment degradation, market demands, and other external disturbances, some processes approach failure conditions. To provide appropriate actions to prevent failure, predictive monitoring and control are needed. To this end, we are currently developing a mathematical theory of process integrity Our study focuses on three major parts: (1) process integrity measure, (2) process integrity control, and (3) plant-wide system integrity. We incorporate existing tools from reliability theory and control theory to assess integrity based on how rapidly recovery can be achieved

Process Modeling

Process models are needed to better analyze and design controllers for chemical processes. We are currently investigating methods for parameter estimation of nonlinear continuous-time systems as well as unstable systems. In particular, we are developing transformatio techniques such as modulating functions to model nonlinear systems and relay schemes to model unstable processes. The development of recursive techniques are being explored for use in on-line for process control and failure diagnosis

Research Interests

  • Process Integrity
  • Process Modeling
  • Plant-Wide Control


  • Ungarala, S., Z.-Z. Chen and T. B. Co, "The theory of process integrity and global analysis for process monitoring and diagnosis," Proceedings of the 4th IFAC Workshop on On-Line Fault Detection and Supervision in theChemical Process Industries (CHEMFAS-4), 2001.
  • S. Ungarala and T. Co, "Model parameter tracking in microbial growthprocesses", AIChE J, 44, 2129-2134 (2000)
  • T.Co, "Relay-Stabilization and Bifurications of Unstable SISO Processes with Time Delay", IEEE Transactions on Automatic Control, Vol. 55, No.5, pp 1131 - 1141, 2010
  • T. Co, "Relay Stabilization and Identification of Unstable Processes", Proceedings of the 17th International Federation of Automatic Control, Seoul, South Korea, July 6-11, 2008.
  • T. Co, "Use spreadsheets to estimate modeling parameters", Chemical Engineering Progress, February, 2008, pp. 45-50.
  • T. Co, "Modeling Dynamic Processes Using Granular Runge-Kutta Methods", Proceedings of the IEEE International Conference on Granular Computing, Silicon Valley, November 2-4, 2007.