ESE PhD candidate Timothy Greco defended his thesis on Spatial Compositions for Agile Quadrupedal Locomotion on Monday, July 20th. Advised by Professor Daniel Koditschek, Greco’s research advances a biologically-inspired approach to understanding legged locomotion, helping to bring its core concepts — describing and controlling agile behaviors by viewing them as compositions of simple dynamical models — into 3D space.
“The ability of this approach to generate robust and agile behaviors suggests that both animal and robotic locomotion reflects this compositional and explainable structure, an insight that can guide the application of other methods of robotic control as well,” Greco says, citing optimization and reinforcement learning as examples.
Obtaining some of the formal stability proofs in a mathematically rigorous way proved challenging throughout Greco’s research. “The main ideas of the proofs are fairly simple and commonly used in control theory, but the problems to which we were applying them demanded that we essentially rebuild them from the ground up,” Greoc explains. Surmounting those challenges required significant iteration with Professor Koditschek to formulate a “suitable proof, but I learned a lot about the math behind it.”
Completing the ESE 5300 Elements of Probability Theory with Professor Santosh Venkatesh stands out as one of Greco’s most memorable experiences at Penn. “It was one of the most conceptually challenging courses I’ve ever taken, and the content had very little direct applicability to my research, but he was one of the best lecturers I’ve ever seen,” Greco said. “Every lecture was fascinating, making me curious about problems I had never considered. And staying up until 2AM with the rest of the first-years in my cohort to finish every problem set was a great way to get to know them.”
Greco expresses deep gratitude to several people for supporting his research. First and foremost, he thanks his advisor Professor Daniel Koditschek, as well as his committee: Professor George Pappas and Professor Michael Posa, “for all of their help and feedback along the way.” Greco extends gratitude to his labmates in the Kodlab, collaborators is GRASP, his parents, family, friends, and girlfriend. Further, Greco extends gratitude to staff support from both GRASP and ESE.
After Penn, Greco is joining Ghost Robotics as a Controls Engineer.
When Greco’s not working, he enjoys “skiing, working out, and spending time with Buster, a Dutch Shepherd puppy whom I am fostering for the Penn Vet Working Dog Center.”
Learn more about Greco’s work here