Tim Bretl


148 Coordinated Science Laboratory

Lab Page
Curriculum Vita

Tim Bretl

Assosciate Professor, Aerospace Engineering
Collins Award for Innovative Teaching, College of Engineering, University of Illinois at Urbana-Champaign, 2015.

AIAA Teacher of the Year Award, AIAA Student Chapter, University of Illinois at Urbana-Champaign, 2015 and 2013.

Best Manipulation Paper Award (for ”Mechanics and Manipulation of Planar Elastic Kinematic Chains,” with Zoe McCarthy), IEEE International Conference on Robotics and Automation, 2012.

Engineering Council award for Excellence in Advising, University of Illinois at Urbana-Champaign, 2011.

CAREER Award, National Science Foundation, 2010.

Theoretical and algorithmic foundations of robotics and automation. Motion planning, control, optimization.

The members of the Bretl Research Group are students, faculty, and affiliates of the University of Illinois at Urbana-Champaign. We have diverse backgrounds and come from a variety of academic departments across engineering and science. Our goals include making prosthetic devices affordable to all who need them, increasing the efficiency and safety of building construction, and lowering barriers to the use of robots for manufacturing automation by small businesses (particularly those owned and controlled by their workers). In pursuit of these goals, we conduct basic research in areas that include electrodiagnostic analysis of brain and muscle activity and control-theoretic analysis of dexterous manipulation and legged locomotion.

Major Grants

(NSF Grant No. 1544999) CPS/Synergy/Collaborative Research: Safe and Efficient Cyber-Physical Operation System for Construction Equipment

(NSF Grant No. 1427111) NRI/Collaborative Research: Improving the Safety and Agility of Robotic Flight with Bat-Inspired Flexible-Winged Robots

(NSF Grant No. 1446765) CPS: Synergy: Autonomous Vision-based Construction Progress Monitoring and Activity Analysis for Building and Infrastructure Projects

(NSF Grant No. 1320519) RI: Small: Mechanics, Manipulation, and Perception of Deformable Objects for Robotic Manufacturing

Representative Publications

A. Akce, J. J. S. Norton, and T. Bretl, “An SSVEP-based brain-computer interface for text spelling with adaptive queries that maximize information gain rates,” IEEE Transactions on Neural Systems and Rehabilitation Engineering, 23(5):857-866, 2015.

J. J. S. Norton, D. S. Lee, J. W. Lee, W. Lee, O. Kwon, P. Won, S.-Y. Jung, H. Cheng, J.-W. Jeong, A. Akce, S. Umunna, I. Na, Y. H. Kwon, X.-Q. Wang, Z. Liu, U. Paik, Y. Huang, T. Bretl, W.-H. Yeo, and J. Rogers, “Soft, curved electrode systems capable of integration on the auricle as a persistent brain–computer interface,” Proceedings of the National Academy of Sciences, 112(13):3920-3925, 2015.

A. Becker, C. Onyuksel, T. Bretl, and J. McLurkin, “Controlling many differential-drive robots with uniform control inputs,” International Journal of Robotics Research, 33(13):1626-1644, 2014.

T. Bretl and Z. McCarthy, “Quasi-static manipulation of a kirchhoff elastic rod based on a geometric analysis of equilibrium configurations,” International Journal of Robotics Research, 33(1):48–68, 2014.

M. W. Kennedy, T. Bretl, and J. P. Schmiedeler, “Interpreting lateral dynamic weight shifts using a simple inverted pendulum model,” Gait & Posture, 40(1):134–139, 2014.

A. Akce, M. Johnson, O. Dantsker, and T. Bretl, “A brain-machine interface to navigate a mobile robot in a planar workspace: enabling humans to fly simulated aircraft with EEG,” IEEE Transactions on Neural Systems and Rehabilitation Engineering, 21(2):306-318, 2013.

T. Bretl and Z. McCarthy, “Mechanics and quasi-static manipulation of planar elastic kinematic chains,” IEEE Transactions on Robotics, 29(1):1–14, 2013.

J.-W. Jeong, W.-H. Yeo, A. Akhtar, J. J. S. Norton, Y.-J. Kwack, S. Li, S.-Y. Jung, Y. Su, W. Lee, J. Xia, H. Cheng, Y. Huang, W.-S. Choi, T. Bretl, and J. A. Rogers, “Materials and optimized designs for human-machine interfaces via epidermal electronics,” Advanced Materials, 25(47):6839-6846, 2013.

A. Becker and T. Bretl, “Approximate Steering of a Unicycle Under Bounded Model Perturbation Using Ensemble Control,” IEEE Transactions on Robotics, 28(3):580-591, 2012.

T. Bretl, “Minimum-time optimal control of many robots that move in the same direction at different speeds,” IEEE Transactions on Robotics, 28(2):351-363, 2012.

R. D. Gregg, A. K. Tilton, S. Candido, T. Bretl, and M. W. Spong, “Control and planning of 3-D dynamic walking with asymptotically stable gait primitives,” IEEE Transactions on Robotics, 28(6):1415– 1423, 2012.

R. Ma, N. Aghasadeghi, J. Jarzebowski, T. Bretl, and T. Coleman, “A stochastic control approach to optimally designing hierarchical flash sets in P300 communication prostheses,” IEEE Transactions on Neural Systems and Rehabilitation Engineering, 20(1):102–112, 2012.

K. A. Shorter, Y. Li, T. Bretl, and E. T. Hsiao-Wecksler, “Modeling, control, and analysis of a robotic assist device,” Mechatronics, 22(8):1067–1077, 2012.

Y. Li, A. Becker, K. A. Shorter, T. Bretl, and E. Hsiao-Wecksler, “Estimating system state during human walking with a powered ankle-foot orthosis,” IEEE/ASME Transactions on Mechatronics, 16(5):835-844, 2011.

C. Omar, A. Akce, M. Johnson, T. Bretl, R. Ma, E. Maclin, M. McCormick, and T. Coleman, “A feedback information-theoretic approach to the design of brain-computer interfaces,” International Journal of Human-Computer Interaction, 27(1):5–23, 2011.

T. Bretl, G. Arechavaleta, A. Akce, and J.-P. Laumond, “Comments on ‘an optimality principle governing human walking’,” IEEE Transactions on Robotics, 26(6):1105–1106, 2010.

T. Bretl and S. Lall, “Testing static equilibrium for legged robots,” IEEE Transactions on Robotics, 24(4):794–807, 2008.

K. Hauser, T. Bretl, J.-C. Latombe, K. Harada, and B. Wilcox, “Motion planning for legged robots on varied terrain,” International Journal of Robotics Research, 27(11-12):1325–1349, 2008.

T. Bretl. "Motion Planning of Multi-Limbed Robots Subject to Equilibrium Constraints: The Free-Climbing Robot Problem" (2006). International Journal of Robotics Research, 25(4): 317-342.

Complete Publications List (PubMed)