(NOTE: THIS IS UNDER CONSTRUCTION)

Research focus is on fundamental and applied aspects of dynamics, control, and structures. Strong mathematical skills combined with  passion for research, desire to innovate, and a motivating curiosity to explore unchartered intelectual teritories are guarantees for success. Proving results that may have the potential of impact beyond what was originally contemplated is highly desired. Some current research topics are given next along with representative journal publications. As revealed by my complete list of journal publications, the following list is not exhaustive.

Note: Publications marked by * are listed under several research topics.  

Rotorcraft Dynamics and Control

Complex, physics based, control oriented models are developed to accurately capture essential rotorcraft dynamics. These models are further used in advanced control for steady and maneuvering flight, failure management via control adaptation, integrated helicopter and control design, passive and active blade morphing, autonomy in shipboard operations, etc.

Sample journal publications

7. Ngo, T., Sultan, C., Model Predictive Control for Helicopter Shipboard Operations in the Ship Airwakes, AIAA Journal of Guidance, Control, and Dynamics, Vol. 39(3), 574-589, 2016

6.  Oktay, T., Sultan, C., Comfortable Helicopter Flight Via Passive/Active Morphing, IEEE Transactions on Aerospace and Electronic Systems, Vol. 51(4), 2776-2786, 2015

5. Oktay, T., Sultan, C., Flight Control Energy Saving via Helicopter Rotor Active Morphing, Journal of Aircraft, AIAA Journal of Aircraft, Vol. 51(6), 1784-1804, 2014  

4. Oktay, T., Sultan C., Modeling and Control of a Helicopter Slung-Load System, Aerospace Science and Technology, Vol. 29, 206-222, 2013

3. Oktay, T., Sultan C., Simultaneous Helicopter and Control System Design, AIAA Journal of Aircraft, Vol. 50(3), 911-925, 2013

2. Oktay, T., Sultan C., Variance Constrained Control of Maneuvering Helicopters with Sensor Failure, Journal of Aerospace Engineering Proc. of the Institute of Mechanical Engineers Part G, to appear

1. Oktay, T., Sultan C., Constrained Predictive Control of Helicopters, Aircraft Engineering and Aerospace Technology, Vol. 85(1), 32-47, 2013

Tensegrity Structures,  Membranes

Prestressable structures such as tensegrity, membranes, as well as general thin structures are investigated. Fundamental theoretical aspects of these structures modeling, design, stability and control are of interest as well as  applications in civil and space engineering, robotics, energy harvesting. 

Journal publications

24. Yang, S., Sultan, C., Deployment of Foldable Tensegrity-Membrane Systems via Transition Between Tensegrity Configurations and Tensegrity-Membrane Configurations, International Journal of Solids and Structures, Vol. 160, 103-119, 2019

23. Yang, S., Sultan, C., LPV Control of a Tensegrity-membrane System, Mechanical Systems and Signal Processing, Vol. 95, 397-424, 2017

22. Yang, S., Sultan, C., A Comparative Study on the Dynamics of Tensegrity-membrane Systems Based on Multiple Models, International Journal of Solids and Structures, Vol. 113, 47-69, 2017

21. Yang, S., Sultan, C., Control Oriented Modeling and Deployment of Tensegrity Membrane Systems, International Journal of Robust and Nonlinear Control, Vol. 27(16),  2722–2748, 2017

20.* Sudalagunta, P.R., Sultan, C., Watson, L., Raj, P., Kapania, R.K., Accurate Computing of Higher Vibration Modes of Thin Flexible Structures, AIAA Journal, Vol. 54(5), 1704-1718, 2016

19. Yang, S., Sultan, C., Modeling of Tensegrity Membrane Systems, International Journal of Solids and Structures, Vol. 82, 125-143, 2016

18. Ferhat, I., Sultan, C., System Analysis and Control Design for a Membrane with Bimorph Actuators, AIAA Journal, Vol. 53(8), 2110-2120, 2015

17. Sultan, C., Tensegrity Deployment Using Infinitesimal Mechanisms, International Journal of Solids and Structures, Vol. 51, 3653-3668, 2014

16.* Sunny, M., Sultan, C., Kapania, R., Optimal Energy Harvesting From a Membrane Attached to a Tensegrity Structure, AIAA Journal, Vol. 52(2), 307-319, 2014

15.* Sultan, C., Decoupling Approximation Design Using the Peak to Peak Gain, Mechanical Systems and Signal Processing, Vol. 36, 582–603, 2013

14. Sultan, C., Stiffness Formulations and Necessary and Sufficient Conditions for Exponential Stability of Prestressable Structures, International Journal of Solids and Structures, Vol. 50(14-15), 2180-2195, 2013

13. Sunny, M., Kapania, R., Sultan, C., Solution of Nonlinear Vibration Problem of a Prestressed Membrane by Adomian Decomposition, AIAA Journal, Vol. 50(8), 1786-1800, 2012

12.* Sultan, C., Proportional Damping Approximation Using the Energy Gain and Simultaneous Perturbation Stochastic Approximation, Mechanical Systems and Signal Processing, Vol. 24(6), 2210-2224, 2010

11.* Sultan, C., Designing Structures for Dynamical Properties via Natural Frequencies Separation. Application to Tensegrity Structures Design, Mechanical Systems and Signal Processing, Vol. 23(4), 1112-1122, 2009

10. Sultan, C., Tensegrity: Sixty Years of Art, Science and Engineering, Advances in Applied Mechanics, Vol. 43, 70-145, 2009

9. Huang, S., Sultan, C., Ingber, D.E., Tensegrity, Dynamic Networks, and Complex Systems Biology: Emergence in Structural and Information Networks within Living Cells. In Complex Systems Science in Bio-Medicine, New York, Springer Verlag, 283-310, 2006

8. Sultan, C., Stamenovic, D., Ingber, D.E., A Computational Tensegrity Model Explains Dynamic Rheological Behaviors of Living Cells, Annals of Biomedical Engineering, Vol. 32(4), 520-530, 2004

7. Sultan, C., Skelton, R. E., A Force and Torque Tensegrity Sensor, Sensors and Actuators: A. Physical, Vol. 112/2-3, 220-231, 2004

6. Sultan, C., Skelton, R.E., Deployment of Tensegrity Structures, International Journal of Solids and Structures, Vol. 40(18), 4637-4657, 2003

5. Sultan, C., Skelton, R. E., Tensegrity Structures Prestressability Investigation, International Journal of Space Structures, Vol. 18(1), 15-30, 2003

4. Sultan, C., Corless, M., Skelton, R.E., Linear Dynamics of Tensegrity Structures, Engineering Structures, Vol. 26(6), 671-685, 2002

3. Sultan, C., Corless, M., Skelton, R.E., Symmetrical Reconfiguration of Tensegrity Structures, International Journal of Solids and Structures, Vol. 39(8), 2215-2234, 2002

2. Sultan, C., Corless, M., Skelton, R.E., The Prestressability Problem of Tensegrity Structures. Some Analytical Solutions, International Journal of Solids and Structures, Vol. 38(30-31), 5223-5252, 2001

1. Sultan, C., Corless, M., Skelton, R.E., Tensegrity Flight Simulator, AIAA Journal of Guidance, Control, and Dynamics, Vol. 23(6), 1055-1064, 2000

Energy Harvesting

Energy harvesting from ocean current turbines (OCT) is of primary interest. Advanced control is pursued for individual devices as well as farms of OCT. Energy harvesting from vibrating structures (e.g. tensegrity-membranes) is also of interest.

Journal publications

4. Pyakurel, P., Van Zwieten, J.H., Sultan, C., Dhanak, M., Xiros, N.I., Numerical Simulation and Dynamical Response of a Moored Hydrokinetic Turbine Operating in the Wake of an Upstream Turbine for Control Design, Renewable Energy, Vol. 114, 1134-1145, 2017

3. Tzelepis, V., Xiros, N.I., Van Zwieten, J.H., Sultan, C., System Modeling and Simulation of In-Stream Hydrokinetic Turbines for Power Management and Control, ASME Journal of Dynamic Systems, Measurement, and Control, Vol. 139(5), 051005-1-0510005-15, 2017

2. Van Zwieten, J., Xiros, N.I., Ngo, T., Sultan, C., An Assessment of Using Variable Blade Pitch for Moored Ocean Current Turbine Flight Control International Journal of Marine Energy, Vol. 13, 16-26, 2016

1.* Sunny, M., Sultan, C., Kapania, R., Optimal Energy Harvesting From a Membrane Attached to a Tensegrity Structure, AIAA Journal, Vol. 52(2), 307-319, 2014

Trajectory Generation, Coordination

Path planning, trajectory, and coordination algorithm for vehicle formations is investigated.

Journal Publications

2. Sultan, C., Seereeram, S., Mehra, R., Deep Space Formation Flying Spacecraft Path Planning, International Journal of Robotics Research, Vol. 20(4), 405-430, 2007

1. Sultan, C., Seereeram, S., Mehra, R., Energy Sub-Optimal Collision-Free Path Planning for Spacecraft Formation Flying, AIAA Journal of Guidance, Control, and Dynamics, Vol. 29(1), 190-192

High Speed Aerospace Vehicles

Control oriented modeling, analysis, and design of hyper/supersonic aerospace vehicle is investigated.  

Journal Publications

4. Sudalagunta, P.R., Sultan, C., Kapania, R.K., Watson, L.T., Raj, P., Aeroelastic Control Oriented Modeling of an Airbreathing Hypersonic Vehicle, AIAA Journal of Guidance, Control, and Dynamics, Vol. 41(5), 1136-114, 2018

3. Morris, C.C., Sultan, C., Schetz, J.A., Kapania, R.K., State Variance Based Approach to Flight Dynamic Constraints in Multidisciplinary Design Optimization, AIAA Journal of Guidance, Control, and Dynamics,  Vol. 40(5), 1206-1220, 2017

2.* Sudalagunta, P.R., Sultan, C., Watson, L., Raj, P., Kapania, R.K., Accurate Computing of Higher Vibration Modes of Thin Flexible Structures, AIAA Journal, Vol. 54(5), 1704-1718, 2016

1. Morris, C.C., Allison, D.L., Schetz, J.A., Kapania, R.K., Sultan, C., Parametric Geometry Model for Design Studies of Tailless Supersonic Aircraft, AIAA Journal of Aircraft, Vol. 51(5), 1455-1466, 2014

Intriguing Topics (Control, Decoupling, Design, etc.)

Journal Publications

4. Sultan, C., Close Tracking of Equilibrium Paths, International Journal of Robust and Nonlinear Control, Vol. 28(6), 2209-2230, 2018

3.* Sultan, C., Decoupling Approximation Design Using the Peak to Peak Gain, Mechanical Systems and Signal Processing, Vol. 36, 582–603, 2013

2.* Sultan, C., Proportional Damping Approximation Using the Energy Gain and Simultaneous Perturbation Stochastic Approximation, Mechanical Systems and Signal Processing, Vol. 24(6), 2210-2224, 2010

1.* Sultan, C., Designing Structures for Dynamical Properties via Natural Frequencies Separation. Application to Tensegrity Structures Design, Mechanical Systems and Signal Processing, Vol. 23(4), 1112-1122, 2009