Randy Freeman joined Northwestern in 1996 after receiving his Ph.D. in Electrical Engineering from the University of California at Santa Barbara. He received the NSF CAREER Award in 1997. He has served as Associate Editor of the IEEE Control Systems Society Conference Editorial Board, has served on Program and Operating Committees for the IEEE Conference on Decision and Control and the American Control Conference, and has served as Associate Editor of the IEEE Transactions on Automatic Control.

Current research interests:

• nonlinear control theory
• robust control, optimal control
• nonlinear system theory
• control and estimation for multi-agent systems

Recent journal publications:

• P. Yang, R.A. Freeman, G.J. Gordon, K.M. Lynch, S.S. Srinivasa, and R. Sukthankar, "Decentralized estimation and control of graph connectivity for mobile sensor networks," Automatica, vol. 46, no. 2. pp. 390–396, Feb. 2010.
• P. Yang, R.A. Freeman, and K.M. Lynch, "Multi-agent coordination by decentralized estimation and control," IEEE Trans. Automat. Contr., vol. 53, no. 11. pp. 2480–2496, Dec. 2008.
• K.M. Lynch, I.B. Schwartz, P. Yang, and R.A. Freeman, "Decentralized environmental modeling by mobile sensor networks," IEEE Trans. Robot., vol. 24, no. 3, pp. 710–724, June 2008.
• A. Chen, G.-Q. Chen, and R.A. Freeman, "Stability of nonlinear feedback systems: a new small-gain theorem," SIAM J. Control Optim., vol. 46, no. 6, pp. 1995–2012, Nov. 2007.
• B.E. Miller, J.E. Colgate, and R.A. Freeman, "On the role of dissipation in haptic systems," IEEE Trans. Robot., vol. 20, no. 4, pp. 768–771, Aug. 2004.
• H. Ito and R.A. Freeman, "Uniting local and global controllers for uncertain nonlinear systems: beyond global inverse optimality," Sys. Control Letters, vol. 45, no. 1, pp. 59–79, 2002.
• H. Ito and R.A. Freeman, "State-dependent scaling design for a unified approach to robust backstepping," Automatica, vol. 37, pp. 843–855, 2001.
• B.E. Miller, J.E. Colgate, and R.A. Freeman, "Guaranteed stability of haptic systems with nonlinear virtual environments," IEEE Trans. Robot. Autom., vol. 16, no. 6, pp. 712–719, Dec. 2000.

Recent conference publications:

• R.A. Freeman, T.R. Nelson, and K.M. Lynch, "A complete characterization of a class of robust linear average consensus protocols," Proceedings of the 2010 American Control Conference, Baltimore, Maryland, pp. 3198–3203, June 2010.
• T.R. Nelson and R.A. Freeman, "Set-valued estimation for mobile sensor networks," Proceedings of the 48th IEEE Conference on Decision and Control, Shanghai, China, pp. 2681–2686, Dec. 2009.
• T.R. Nelson and R.A. Freeman, "Decentralized H_∞ filtering in a multi-agent system," Proceedings of the 2009 American Control Conference, St. Louis, Missouri, pp. 5755–5760, June 2009.
• P. Yang, R.A. Freeman, G.J. Gordon, K.M. Lynch, S.S. Srinivasa, and R. Sukthankar, "Decentralized estimation and control of graph connectivity in mobile sensor networks," Proceedings of the 2008 American Control Conference, Seattle, Washington, pp. 2678–2683, June 2008.
• P. Yang, R.A. Freeman, and K.M. Lynch, "A general stability condition for multi-agent coordination by coupled estimation and control," Proceedings of the 2007 American Control Conference, New York, pp. 723–728, July 2007.
• P. Yang, R.A. Freeman, and K.M. Lynch, "Distributed cooperative active sensing using consensus filters," Proceedings of the IEEE Int. Conf. Robotics and Automation, Rome, Italy, pp. 405–410, Apr. 2007.
• R.A. Freeman, P. Yang, and K.M. Lynch, "Stability and convergence properties of dynamic average consensus estimators," Proceedings of the 45th IEEE Conference on Decision and Control, San Diego, California, pp. 398–403, Dec. 2006.
• R.A. Freeman, P. Yang, and K.M. Lynch, "Distributed estimation and control of swarm formation statistics," Proceedings of the 2006 American Control Conference, Minneapolis, Minnesota, pp. 749–755, June 2006.
• P. Yang, K.M. Lynch, and R.A. Freeman, "Optimal information propagation in sensor networks," Proceedings of the 2006 IEEE International Conference on Robotics and Automation, Orlando, Florida, pp. 3122–3127, May 2006.
• A. Chen, G.-Q. Chen, and R.A. Freeman, "Conditional gain is necessary and sufficient for the robust stabilization of nonlinear systems," in Proceedings of the 43rd IEEE Conference on Decision and Control, Paradise Island, Bahamas, pp. 1347–1351, Dec. 2004.
• R.A. Freeman, "On the relationships between induced l_∞-gain and various notions of dissipativity" in Proceedings of the 43rd IEEE Conference on Decision and Control, Paradise Island, Bahamas, pp. 3430–3434, Dec. 2004.
• R.A. Freeman, "On the necessity of the small-gain theorem in the performance analysis of nonlinear systems," in Proceedings of the 40th IEEE Conference on Decision and Control, Orlando, Florida, pp. 51–56, Dec. 2001.
• R.A. Freeman, "On the necessity of the small-gain theorem for nonlinear systems without fading memory," in Proceedings of the 39th Annual Allerton Conference on Communication, Control, and Computing, Monticello, Illinois, pp. 1225–1233, Oct. 2001.
• B.E. Miller, J.E. Colgate, and R.A. Freeman, "Environment delay in haptic systems," in Proceedings of the 2000 IEEE International Conference on Robotics and Automation, San Francisco, California, pp. 2434–2439, 2000.
• B.E. Miller, J.E. Colgate, and R.A. Freeman, "Framework for the design of stable haptic systems," in Proceedings of the World Automation Conference ISORA, Maui, Hawaii, 2000.
• V. Rawls and R.A. Freeman, "Comparison of receding horizon control and an adaptive approach to cost reduction using Lyapunov design in nonlinear systems," in Proceedings of the 2000 American Control Conference, Chicago, Illinois, pp. 265–269, June 2000.
• V. Rawls and R.A. Freeman, "Adaptive minimum-cost Lyapunov-descent control of nonlinear systems," in Proceedings of the 2000 American Control Conference, Chicago, Illinois, pp. 1649–1653, June 2000.