faculty.Jeffrey T. Scruggs

Jeffrey T. Scruggs, Assistant Professor

Professor Scruggs's research concerns the dynamics and control of electromechanical vibratory systems. His research bridges the fields of power electronics, structural mechanics, and nonlinear control.  The general concepts of his work are applicable in many areas, including civil structures, aerospace systems, vehicle suspensions, and MEMS.

One current project concerns the control of seismically-excited civil structures, toward the reduction of risk. Due to the unreliability of external power during earthquakes, such systems must operate in the absence of external power. This research considers control systems which electrically extract energy from a structure, using motors as transducers. By using power electronics to manage this extracted energy, it can be dissipated, transmitted from one place in a structure to another, or stored for reuse. These capabilities can be used to achieve superior performance to that obtainable with simpler passive systems.

Another current project involves tensegrity structures. These are truss structures in which cables are used for all tensile members. They are appealing in applications requiring structures to be lightweight, flexible, controllable, or reconfigurable. This research concerns the use of electronic systems to generate energy from the motion of externally-excited tensegrity structures. Of particular interest is the use of such systems to harvest energy from the motion of ocean waves.

Research Interests

• Mechatronic systems for vibrating structures
• Nonlinear control of systems with constrained actuation
• Reliability-based structural design and control
• Semiactive vibration suppression
• Dynamics and control of tensegrity structures
• Energy harvesting applications

Education

• Ph.D., Applied Mechanics, Caltech, 2004
• M.S., Applied Mechanics, Caltech, 2000
• M.S. Electrical Engineering, Virginia Tech, 1999
• B.S., Electrical Engineering, Virginia Tech, 1997

Professional Experience

• Postdoctoral Research Associate, University of California, San Diego Supervisor: Prof. R.E. Skelton, November 2005 – December 2006.
• G.W. Housner Postdoctoral Research Fellow, California Institute of Technology, July 2004 – October 2005
• Instructor, California Institute of Technology, Sept. 2004 – May 2005
• Teaching Assistant, California Institute of Technology, Sept. 2002 – May 2004
• Moore Graduate Research Fellow, California Institute of Technology, Sept. 1999 – May 2003
• H.L. Bradley Graduate Research Fellow, Virginia Tech, August 1997 – August 1999

Sample Publications

• Scruggs, J.T., A.A. Taflanidis, W.D. Iwan. “Nonlinear Controllers for Semiactive & Regenerative Systems with Guaranteed Quadratic Performance Bounds.” 4th World Conf. Structural Control, San Diego, July 2006.
• Scruggs, J.T. and R.E. Skelton. “Regenerative Tensegrity Structures for Energy Harvesting Applications.” 45th IEEE Conf. on Decision & Control, San Diego, Dec. 2006.
• Scruggs, J.T. and W.D. Iwan. “Optimal Non-Local and Asymmetric Linear Structural Damping with Regenerative Force Actuators.” ASCE J. Engineering Mechanics (in press).
• Scruggs, J.T., A.A. Taflanidis, J.L. Beck. (2006) “Reliability-Based Control Optimization for Active Base Isolation Systems.” J. Structural Control & Health Monitoring, 13(2-3), 705-723.
• Scruggs, J.T. and W.D. Iwan. (2005). “Structural Control with Regenerative Force Actuation Networks.” J. Structural Control & Health Monitoring, 12(1), 25-46.
• Scruggs, J.T. and W.D. Iwan. (2003). “Control of a Civil Structure Using an Electric Machine with Semiactive Capability.” ASCE J. Structural Engineering, 129(7), 951-959.

Professional and Service Activities

• Reviewer for ASCE Journal of Engineering Mechanics, IEEE Transactions on Control Systems Technology, & International Journal of Nonlinear Mechanics.
• Member of ASCE, IEEE, and HKN