Current Research Projects

I work in control theory and its applications. The following is a brief listing of recent papers from research projects that I am pursuing now (some alone, others with graduate students or other faculty). The description that I have for each area is pretty low tech! Mostly some general description and the citation to a recent paper or two (or three, or ...) As I become a little bit more literate (`home-page wise' speaking) I will put up more pictures and plots or automatic paper downloading. For now, if you want any of my papers, just email me.

Research in control theory

Applications to civil engineering and `Semi-active' techniques

Collaborative work in fluids and Fuel Cell related work

Control Theory :

In control theory, my interests lie in design of control laws for uncertain, or more generally speaking linear parmeter varying, systems. More recently, I have been working on the saturation problem and its connections to parameter varying structure.

Selected References

Kim, J.H., and Jabbari, F., ``A scheduling approach for tracking of general signals," accepted in International Journal of Control , 2007

Sajjadi-Kia, S., Jabbari, F., ``Use of Scheduling for Anti-Windup Controller Design," Proceedings of American Control Conference, 2007, July 07, New York, NY.

Sajjadi-Kia, S., Jabbari, F., ``Combining anti-windup and over-saturation," Proceedings of AIAA Guidance, Navigation and Control Conference and Exhibit, August 20-23, 2007, Hilton Head South Carolina. AIAA Paper 2007-6401

Sajjadi-Kia, S., Jabbari, F., ``Dilated Matrix Inequalities for Control Design in Systems with Actuator Constraint," Proceedings of CDC-07, Dec 112-14, 2007, New Orleans, LA.

Sajjadi-Kia, S., Jabbari, F., ``Scheduling in Anti-windup Controllers: Output Feedback Case," Proceedings of CDC-07, Dec 112-14, 2007, New Orleans, LA.

Sajjadi-Kia, S., Farre, A., Jabbari, F., ``Scheduled anti-windup controllers for application to aircraft in unstable operating conditions," Proceedings of AIAA Guidance, Navigation and Control Conference and Exhibit, August 20-23, 2007, Hilton Head South Carolina. AIAA paper 2007-6416

Jabbari, F., Kim, J-H., ``Scheduled controllers for buildings under seismic excitation with limited actuator capacity," J. of Engineering Mechanics , ASCE, vol 130, no 7, July 2004, pp. 800-808

Jabbari, F., Kose, I.E., ``Rate and magnitude bounded actuators: scheduled output feedback design, International journal of Robust and Nonlinear Control , vol 14, 2004, pp. 1169-84.

Kose, I.E., Jabbari, F., `` Scheduled controllers for linear systems with saturating actuator," Automatica , Vol. 39, No 8, pp. 1377-87, 2003.

Kim, K-S., Jabbari, F., ``Disturbance attenuation via strictly positive real compensators, " Journal of the Franklin Institute , vol 340, 2003, pp 515-521.

This research is a joint project with Professor and Yang (who is a member of the Civil Engineering Department) and Professor Kim (from Korea), as well as Professor Bobrow of UCI. The main focus of this project (which is funded by NSF) is to use recent development in control theory to design control laws for applications to civil structures (to reduce the effects of ground motion or strong wind gusts). Most of the work so far has been analytical, though some experiments were conducted at the National Earthquake Engineering Research Center. A big part is development of semi-active actuators. The basic idea is to manipulate the effective damping or stiffness of the system on-line. The main thrust is to develop control laws that use very small amounts of energy, namely enough to open and close a value (this is why sometimes these techniques are called `semi-active'). The progress so far includes control laws and actuators that are decentralized, reliable and cheap. They also can be used as guidelines in design consideration (e.g., placement of sensors). Professor Bobrow is the key experimentalist in this project.

Selected References

Bobrow, J.E., and Jabbari, F., ``Design of a 20,000 pound variable stiffness actuator for shock and vibration attenuation," accepted in ASME J. on Shock and Vibration , 2007

Yang, J.N., Bobrow, J., Jabbari, F., Leavitt, J., Cheng, C.P., Lin, P.Y., ``Full-scale experimental varication of resetable semi-active stiffness dampers, Earthquake Engineering and Structural Dynamics , vol 36, 2007, pp 1255-1273

Ngyuen, T., Leavitt, J., Jabbari, F., Bobrow, J.E.,, ``Accurate sliding mode control of pneumatic systems using low cost solenoid valves," IEEE/ASME Transactions on Mechatronic , Volume 12, no 2, April 2007

Leavitt, J., Jabbari, F., Bobrow, J.E., ``Optimal Performance Of Variable Stiffness Devices For Structural Control'', ASME Journal of Dynamics, Measurement and Control , March 2007, pp 171-177

Leavitt, J.L., Bobrow, J.E., Jabbari, F., Yang, J.N., ``Application of a high-pressure gas semi-active resetable damper to the benchmark smart base-isolated buildings, " Journal of Structural Control and Health Monitoring , vol 13, 2006, pp. 748-757

Yang, J.N., Lin, S., Jabbari, F., ``H-infinity based control strategies for civil engineering structures," J. of Structural Engineering , vol 11, 2004 , pp 223-237.

Yang, J.N., Lin, S., Jabbari, F., ``Linear multi-objective control strategies for civil engineering structures, " Journal of Engineering Mechanics , ASCE, April 2004.

Yang, J.N., Lin, S., Jabbari, F., ``H_$ based strategies for civil engineering structures, " Journal of Structural Control , 2003 (in press)

Jabbari, F., Kim, J-H., ``Scheduled controllers for buildings under seismic excitation with limited actuator capacity," J. of Engineering Mechanics ASCE, vol 130, n0 7, July 2004, pp. 800-808.

This a joint research projects, with my colleague Professor Dunn-Rankin. Our current efforts were originally funded through a small seed grand from CIEE and more recently by a grant from NSF. Our main focus is on developing techniques for controlling the size of droplets, over a wide range of sizes and conditions, that are generated in a capillary stream break-up.

I am also involved with UCI National Center for Fuel Cell Research, which is funded by a variety of sources including CEC, to look into dynamic modeling and control issues in Fuel Cells.

Selected References

Rohani, m., Iobbi, D.K., Dunn-Rankin, D. and Jabbari, F. ``Controlling Liquid Jet Breakup with Practical Piezoelectric devices," accepted in Atomization and Spray , 2007

Rohani, M., Dunn-Rankin, D., Jabbari, F., ``Predicting breakup characteristics of liquid jets disturbed by practical piezoelectric devices," Proceedings of 20th Conference on Liquid Atomization and Spray Systems (ILASS), May 2007, Chicago, Il.

Mueller, F., Gaynor, R., Auld, A.E., Brouwer, J., Jabbari, F., Samuelsen, G.S., ``Synergistic integration of a gas turbine and solid oxide fuel cell for improved transient capability," Journal of Power Sources , vol. 176, 2008, pp 229-239.

Mueller, F., Jabbari, F., Gaynor, R., Brouwer, J., ``Novel solid oxide fuel cell system controller for rapid load following, Journal of Power Sources , 2007

Mueller, F., Jabbari, F., Brouwer, J., Roberts, R., ``Control design for a bottoming solid oxide fuel cell gas turbine hybrid system," ASME Journal of Fuel Cell Science and Technology ,August 2007, pp 221-230.

Roberts, R., Brouwer, J. Jabbari, F., Junker, T., Ghezel-Ayahg, H., ``Control design of an atmospheric solid oxide fuel cell/gas turbine hybrid systems: Variable versus fixed speed has turbine operation, Journal of Power Sources , vol 161, 2006, pp 484-491

Mueller, F., Brouwer, J., Jabbari, F., Samuelsen, G.S., ``Dynamic simulation of an integrated solid oxide fuel cell system including current based fuel flow control," ASME Journal of Fuel Cell Science and Technology , vol vol 3, May 2006, pp 144-154.

Meecham, J.R., Jabbari, F., Brouwer, J., Mauzey, J.L., Samuelsen, G.S., ``Analysis of stationary fuel cell dynamic ramping capabilities and ultra capacitor energy storage using high resolution demand data," , Journal of Power Sources , vol 156, 2006, pp 472-479

Brouwer, J., Jabbari, F., Martin Leal, E., Orr, T., ``Analysis of a molten carbonate fuel cell: numerical modeling and experimental validation," Journal of Power Sources , vol 158, 2006, pp 213-224.