B.S. in Chemical Engineering, National Institute of Technology, Warangal, India (2003).
M.S. in Chemical Engineering, Indian Institute of Technology Bombay, India (2005).
Honors and Awards:
- SBC Chancellor’s Fellowship recipient for the years of 2005-08, TTU.
- R. G. Manudhane M.Tech. Student Excellence Award 2005, IIT.
- Nominated for P.C. Ray award for The Best Bachelor’s Thesis – 2003, Indian Institute of Chemical Engineers, Kolkata, India.
PhD Research Topic:
Modeling, Identification and, Control of Complex Systems – A New Paradigm
Understanding the physical phenomena and ‘engineering’ the processes involve methods to correlate process parameters that determine the progression and state of the process. These correlations form the basis for engineering analysis, design, optimization and control of the process of interest. However, in practice there is no perfect mathematical model that can accurately represent a physical process. This is because of various reasons namely; uncertainty in the process, nonlinearity associated with cause and effect relationships, and time varying external disturbances.
Usage of linear dynamic models for describing such systems irrespective of their complex nature is pervasive in control engineering applications. Such models are useful only in small ranges of operating conditions and may be no longer valid outside this window. This can be mathematically perceived as a change in the input-output causality when the system operating conditions are different from that of the conditions when the linear dynamic model is built. However, poor agreement between model predictions and output data does not imply that input-output causality has changed from the time of modeling, because the unmodeled component may not be necessarily from change in process dynamics. Very often time-varying external disturbances that are entering the process may lead to plant-model mismatch. For these reasons, model validation is an important tool which is used not only as a final ‘quality control station’ before controller deployment, but also as ‘supervisor station’ whiles the controller is active to detect any changes in process behavior. While the model validation at the initial system identification stage is well addressed, on-line model validation using closed-loop data is still a challenging area. Even after isolating the proper root cause for plant model mismatch (PMM), it is a difficult task to perform system identification in presence non-stationary external disturbances.
In this work, an attempt has been made to resolve some of the issues posed by above mentioned complexities using simple linear dynamic models. Following figure outlines the major contributions of my research.
- Srinivas Karra, and M. Nazmul Karim, 2009. “Automatic Detection and Daignosis of Oscillatory Control Loops”, accepted for publication in Control Engineering Practice.
- Srinivas Karra, and M. Nazmul Karim, 2009. “Alternative Model Structure with Simplistic Noise Model to Identify Linear Time Invariant Systems Subjected to Non-Stationary Disturbances”, Journal of Process Control, doi:10.1016/j.jpcont.2008.12.007
- Christopher Betts, Srinivas Karra, M. Nazmul Karim and James B. Riggs, 2009. "A modified extended recursive least-squares method for closed-loop identification", accepted for publication in Industrial Engineering and Chemistry Research Journal.
- Srinivas Karra, and M. Nazmul Karim, 2009. “Integrated performance assessment and model validation for model based predictive control applications”, in preperation for Journal of Process Control.
- Srinivas Karra, Brian Sager and M. Nazmul Karim, 2009, “Robust predictive control strategies for glycemic regulation in insulin dependent diabetes patients”, in preparation – IEEE Transactions on Biomedical Engineering.
- Srinivas Karra, Rajesh Shaw, Sachin C. Patwardhan and Santosh Nornha, 2008,“ Adaptive Model Predictive Control of Multivariable Time-varying Systems”, Industrial Engineering and Chemistry Research Journal, 47(8), 2708-2720.
- Suma Peri, Srinivas Karra, Y.Y. Lee, and M. Nazmul Karim, 2007, “Modeling intrinsic kinetics of enzymatic cellulose hydrolysis”, Biotechnology Progress, 23(3), 626-637.
Peer Reviewed Conference Proceedings:
- Srinivas Karra and M. Nazmul Karim, “Modeling, Identification and Control of Complex Systems – A New Paradigm”, Key Note Lecture in Systematic Methods and Tools for Managing the Complexity-II, 10th International Chemical and Biological Engineering Conference, September 4-6, 2008, Braga, Portugal.
- Srinivas Karra and M. Nazmul Karim, “Modeling of CHO Cell Culture Processes”, Systematic Methods and Tools for Managing the Complexity II, 10th International Chemical and Biological Engineering Conference, September 4-6, 2008, Braga, Portugal.
- Suma Peri, Srinivas Karra, Y.Y. Lee, and M. Nazmul Karim, " Modeling for Optimization of Enzymatic Hydrolysis of Cellulose", proceedings in 10th International IFAC Symposium on Computer Applications in Biotechnology, June 4-6, 2007, Cancun, Mexico.
- Srinivas Karra, M. Nazmul Karim, and Binbing Han, " Predictive Control of Blood Glucose Concentration in Type-I Diabetic Patients using Linear Input-Output Models", in 10th International IFAC Symposium on Computer Applications in Biotechnology, June 4-6, 2007, Cancun, Mexico.
- James B. Riggs, Christopher L. Betts, M. Nazmul Karim and Srinivas Karra, “Closed-Loop Model Identification”, filed for disclosure at Office of Technology Transfer and Intellectual Property, TTU, dt. 06/21/2008.
- Srinivas Karra, and M. Nazmul Karim, “Detection, Discrimination and Diagnosis of Oscillatory Feed-back Control Loops”, filed for disclosure at Office of Technology Transfer and Intellectual Property, TTU, dt. 08/16/2007.
- Srinivas Karra, M. Jelali, and A. Horch, “Detection of oscillating control loops”, Chapter in Book titled: 'Detection and diagonosis of stiction in control loops: State of the art and advacned methods', M. Jelali and B. Huang (eds.), Springer-Verlag, proposal accepted Feb, 2008.
- Srinivas Karra, and M. Nazmul Karim, “Oscillation root-cause detection and quantification”, Chapter in Book titled: ' Detection and diagnosis of stiction in control loops: State of the art and advanced methods ', M. Jelali and B. Huang (eds.), Springer-Verlag, proposal accepted Feb, 2008.
*Address all inquiries to Dr. Nazmul Karim