Abstract

We develop a hybrid controller for global asymptotic stabilization on the n-dimensional sphere using synergistic potential functions. These consist of a collection of potential functions that induce a gradient descent controller during flows of the hybrid closed-loop system and a switching law that, at undesired equilibrium points of the gradient vector field, jumps to the lowest value among all the potential functions in the collection. We show that the proposed controller can be used for global reduced attitude synchronization, i.e., given a network of rigid-bodies, the proposed synergistic hybrid feedback can be used to globally synchronize a reference direction of each agent within a global but unknown inertial reference frame. We study this application for a network of three vehicles by means of simulation results.

Bio

Pedro Casau is a Research Assistant at the SCORE Lab of the Faculty of Science and Technology, University of Macau. He received received the B.Sc. in Aerospace Engineering in 2008 from Instituto Superior Técnico (IST), Lisbon, Portugal.  In 2010, he received the M.Sc. in Aerospace Engineering from IST and enrolled in the Electrical and Computer Engineering Ph.D. program at the same institution which he completed with distinction and honours in 2016. While at IST, he participated on several national and international research projects on guidance, navigation and control of unmanned air vehicles (UAVs) and satellites. His current research interests include nonlinear control, hybrid control systems, vision-based control systems, controller design for autonomous air-vehicles.