Faculty Candidate Seminar

Autonomy Through Geometry: From Surgical Needle Steering to Cooperative Robot Control

Vinutha Kallem

Research Scientist
University of Pennsylvania
Tuesday, April 05, 2011
09:00am - 10:00am
1005 EECS

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About the Event

In this talk, I will present algorithms that leverage the geometric structure of the control problem to navigate robotic systems in complex environments. First, I will discuss image-guided controllers for steerable needle insertions to reach percutaneous targets for biopsies or drug delivery while avoiding sensitive organs and anatomical obstacles. We develop nonlinear observer-based controllers, which we use with subspace planners to drive the needle tip to a desired location inside the tissue. We show that the tasks of these controllers induce symmetry, resulting in a reduced system that greatly simplifies controller and observer design. We then propose a method to perform such "task-induced" reductions for a broader class of nonholonomic systems on Lie groups. Second, I will present control algorithms for cooperative robots while maintaining communication needs and avoiding inter-robot collisions and obstacles. To achieve this, we decompose the free space into obstacle-free cells and generate local smooth feedback laws that drive a single robot or a team of robots from one cell to an adjoining cell. These local controllers are then sequenced using discrete graph search methods like A* or incremental D* to reach the goal. Because each local controller is designed to reach a submanifold, this local task is exploited to overcome geometric and nonholonomic constraints. We demonstrate successful implementations on ground and flying robots to show the robustness of the algorithms to changes in environment topologies and uncertainties in modeling and measurement.


Vinutha Kallem is a Research Scientist at the University of Pennsylvania in the GRASP Laboratory. Her research aims to provide autonomy in mobile robotic systems and supervised autonomy for surgical systems. Her research interests include dynamical systems, control theory, robotics, and their applications in solving real-world problems that arise in mobile systems, medicine, and health care. Dr. Kallem received her Ph.D. in Mechanical Engineering from Johns Hopkins University in 2008, where she was also a recipient of the Heath Fellowship. Dr. Kallem has an M.S. from Stanford University and a B.Tech. from the Indian Institute of Technology - Madras, both in Mechanical Engineering.

Additional Information

Contact: Beth Olsen

Phone: 734 763-8040


Sponsor(s): ECE

Open to: Public