Robust Agility and Safety for Dynamic Aerial Manipulation and Legged Locomotion

Presented on October 26, 2016 from 12:00 p.m.-1:00 p.m in the Marcus Nanotechnology Building, Rooms 1116-1118 on the Georgia Tech campus.Koushil Sreenath is an assistant professor in the departments of Mechanical Engineering and Electrical & Computer Engineering at Carnegie Mellon University. He is also a member of CMU’s Robotics Institute. In 2011, Sreenath received a Ph.D. in Electrical Engineering: Systems and an M.S. degree in Applied Mathematics from the University of Michigan at Ann Arbor. His research interest lies at the intersection of highly dynamic robotics and applied nonlinear control. His work on dynamic legged locomotion on the bipedal robot MABEL was featured on The Discovery Channel, CNN, ESPN, FOX, and CBS. His work on dynamic aerial manipulation was featured on the IEEE Spectrum, New Scientist, and Huffington Post. Additionally, his work on adaptive sampling with mobile sensor networks was published as a book entitled Adaptive Sampling with Mobile WSN (IET). Sreenath received the best paper award at the Robotics: Science and Systems (RSS) Conference in 2013, and the Google Faculty Research Award in Robotics in 2015.Runtime: 49:46 minutesBiological systems are able to move with great elegance, agility, and efficiency in a wide range of environments. Endowing machines with similar capabilities requires designing controllers that can address the challenges of high-degree-of-freedom, high-degree-of-underactuation, nonlinear dynamics, while simultaneously enforcing constraints of available actuators, sensors and processors. In this talk, I will present the design of planning and control policies for two problems - dynamic aerial manipulation and dynamic legged locomotion. First, I will show how a coordinate-free, geometric mechanics formulation of the dynamics of a quadrotor carrying a suspended payload allows us to synthesize nonlinear geometric controllers with almost-global stability properties for aggressive maneuvers. I will present the problem of cooperative transportation of a cable-suspended payload using multiple aerial robots, and show how we can design dynamically feasible trajectories that can handle hybrid dynamics resulting from the cable tension going to zero. Next, I will present the design of control policies for dynamic bipedal locomotion by explicitly considering the nonlinear and hybrid dynamics of bipedal robots subject to input torque constraints, contact force constraints, and safety-critical constraints. This is achieved through control Lyapunov and Barrier functions. In addition, I will show that the adverse of effects of model uncertainty on both stability and constraint enforcement can be addressed through a robust formulation of control Lyapunov and Barrier functions