Robotics and Artificial Intelligence

Biography

Biography: Ziad Zamzami

Abstract

Humans and animals are capable of overcoming complex terrain challenges with graceful and agile movements. One of the key ingredients for such complex behaviors is motion coordination to exploit their natural dynamics. Sports performers coordinate their action in many different ways to achieve their goals. Coordination is a key feature in highly dynamic maneuvers ranging from the graceful, precise action of an ice dancer to the explosive, physical power of a triple jumper. Lizard coordinates its tail swing to stabilize its dynamic motion over rough terrain. Cheetah can rapidly accelerate and maneuver during the pursuit of its prey by the coordinating of the motion of its tail. Understanding and emulating these motions is one of the long-standing grand challenges in robotics and biomechanics with possible applications in rehabilitation, sport, search-and-rescue, environmental monitoring and security. Despite the existence of powerful tools such as nonlinear trajectory optimization, they are usually treated as black boxes that provide local optimal trajectories. We introduce the Dynamical Coupling Map (DCM), a novel graphical technique, to help gain insight into the output trajectory of the optimization and analyze the capability of underactuated robots. As examples of dynamic maneuvers, the DCM analysis is demonstrated on the swing-up motion of a simplified model of a gymnast on high bar as well as a vertical jump for a high-dimensional humanoid robot with arms swing. The DCM shows graphically and intuitively the pivotal role of exploiting the natural dynamics in order to exceed their physical capacity which is dictated by the input torques limits. We also extend the current posteriori analysis to exploiting the natural dynamics as a priori for guiding motion generation of highly dynamic maneuvers.