Research Team



Rifat Sipahi, PhD


Photo: Courtesy of Mary Knox Merrill/Northeastern University


Office: 321 Snell Engineering Center.

Phone: (617) 373 6011.

Email: rifat AT coe DOT neu DOT edu

Just got back from 2015 IFAC Workshop on Time Delay Systems

As several of you also noticed and mentioned me at the workshop, our group at NEU owns the novel and original contributions in the exact computation of upper/lower bounds of frequency spectrum of multiple delay LTI systems using "discriminants", and in the use of frequency sweeping as a novel connection to identifying "2D stability charts" of such systems in the presence of more than three delays, where some delays are fixed a priori. These developments extend the elegant ideas of Cooke and van den Driessche (1986).

Here are the two papers where original ideas were published (others in publication list):

Sipahi, R., Delice, I.I., 2011, Advanced Clustering with Frequency Sweeping Methodology for the Stability Analysis of Multiple Time-Delay Systems, IEEE Transactions on Automatic Control, 56(2), 467-472

Delice, I.I., Sipahi, R., 2012, Delay-Independent Stability Test for Systems with Multiple Time-Delays, IEEE Transactions on Automatic Control, 57(4), pp. 963-972.




  • 2013 European Control Conference, Zurich, Switzerland
  • 2013 Ieee Conference On Decision And Control, Florence, Italy
  • 2014 European Control Conference, Strasbourg, France


  • Fatihcan M. Atay, GERMANY

  • Dimitri Breda, ITALY

  • Wim Michiels, BELGIUM

  • Silviu-Iulian Niculescu, FRANCE

  • Hitay Ozbay, TURKEY

  • Rifat Sipahi, USA



  • Sipahi elected ASME Fellow (2014)

  • Sipahi elected Faculty Fellow, College of Engineering, NU (2014)

  • According to the statistics from Springer Verlag, over 18,000 times chapter downloads were recorded from the volume edited by Loiseau, J.-J. Niculescu, S.-I., Michiels, W., Sipahi, R., from August 11, 2009 to June, 2014.

  • According to the statistics from Springer Verlag, over 23,000 times chapter downloads were recorded from the volume edited by Sipahi, R., Vyhlidal, T., Niculescu, S.-I., Pepe, P., from February 23, 2012 to June, 2014.

  • According to the statistics from Springer Verlag, over 24,000 times chapter downloads were recorded from the volume edited by Vyhlidal, T., Lafay, J.-F., Sipahi, R., from September 10, 2013 to June, 2014.

  • Sipahi gave a plenary talk at the past IEEE International Conference on Electrical Engineering, Computing Science¬†and Automatic Control held in Mexico City.

  • Sipahi's plenary talk can be accessed via YouTube at http://www.youtube.com/watch?v=8Vt4ySkgcrE

  • Sipahi was awarded the 2011 DARPA Young Faculty Award.

  • Sipahi was awarded the 2011 Martin Essigman Outstanding Teaching Award of the College of Engineering.

  • What's with the delay? -- Sipahi is in the news @ Northeastern.

Active research & engineering education topics
  • Novel results in LTI systems with multiple delays, both in delay-dependent and delay-independent stability (since 2001)

  • Novel control design techniques to enhance effectiveness of man-machine systems (since 2010)

  • Engineering solutions in ways to suppress hand tremors in daily tasks (since 2010)

  • Mechatronics based portable Braille writing device (since 2009)

  • Development of new hands-on mechatronics curriculum covering energy systems, bioengineering, biomedical devices, and sustainability (since 2011)

  • Responsible Eigenvalue concepts in networked systems in presence of delays. Design of network topologies that can withstand larger delays without losing stability (since 2006)


Mailing Address: 334 Snell Engineering Center, 360 Huntington Avenue, Northeastern University, Boston, MA 02115