The IASTED International Conference on
Engineering and Applied Science
EAS 2012

Engineering Applications for the 21st Century

December 27 – 29, 2012
Colombo, Sri Lanka


Novel Developments in Intelligent Systems Approaches to Control of UAV Systems and Formations

Tong H. Lee
The National University of Singapore, Singapore


This Keynote presentation will firstly, consider pertinent general recent developments in intelligent automation, mechatronics and systems; and then more specifically, consider the development of an intelligent and hybrid control structure for a group of cooperative Unmanned Aerial Vehicles (UAVs), which covers the control sub-module interactions, and captures the discrete nature of the decision making unit and continuous evolution of the system collectively. To achieve such a goal which has rather mixed hybrid/switched systems constituents, the development uses two parts: first, the hybrid modeling and control of a single UAV is established; and next, the development then deals with the team behavior of several UAVs in formation. To construct such a hybrid model of a single UAV, we develop a semi-linearized model of a UAV helicopter, and establish an effective multi-layer low-level controller for the UAV helicopter, using the H-Inf control-design technique in the inner-loop and employing a decentralized feedback controller combined with non-linear compensation in the outer-loop. This suitably novel approach for the design of the outer-loop controller of the UAV provides rather successful flight control at this first-level. Using this model, we then develop a hierarchical hybrid controller for the single UAV stage, which consists of three layers: regulation layer, coordination layer, and supervision layer. Next, a suitably new approach of hybrid supervisory control of the UAVs is developed for leader-follower formations, within a cooperative scenario. Such an approach is able to comprehensively capture the internal relations between the path-planner dynamics and the decision-making unit of the UAVs. In the design for such a hybrid supervisory controller for the formation problem, a method of abstraction, based on polar-partitioning of the state-space, is introduced. Then, the properties of the multi-affine vector fields over the polar partitioned space are utilized. Within this framework, a modular decentralized supervisor in the path-planner level of the UAVs is then designed to achieve two major goals: first, reaching the formation; and second, keeping the formation. In addition, an inter-collision avoidance mechanism is embedded in the controller structure. Additionally, various other recent new developments in intelligent automation, mechatronics and systems will be discussed.

Biography of the Keynote Speaker

Keynote Speaker Portrait


T. H. Lee
received the B.A. degree with First Class Honours in the Engineering Tripos from Cambridge University, England, in 1980; and the Ph.D. degree from Yale University in 1987. He is a Professor in the Department of Electrical and Computer Engineering at the National University of Singapore (NUS); and also a Professor in the NUS Graduate School, NUS NGS. He was a Past Vice-President (Research) of NUS.
Dr. Lee’s research interests are in the areas of adaptive systems, knowledge-based control, intelligent mechatronics and computational intelligence. He currently holds Associate Editor appointments in the IEEE Transactions in Systems, Man and Cybernetics; IEEE Transactions in Industrial Electronics; Control Engineering Practice (an IFAC journal); and the International Journal of Systems Science (Taylor and Francis, London). In addition, he is the Deputy Editor-in-Chief of IFAC Mechatronics journal.
Dr. Lee was a recipient of the Cambridge University Charles Baker Prize in Engineering; the 2004 ASCC (Melbourne) Best Industrial Control Application Paper Prize; the 2009 IEEE ICMA Best Paper in Automation Prize; and the 2009 ASCC Best Application Paper Prize. He has also co-authored five research monographs (books), and holds four patents (two of which are in the technology area of adaptive systems, and the other two are in the area of intelligent mechatronics). He has published more than 300 international journal papers.
Dr. Lee was an Invited Panelist at the World Automation Congress, WAC2000 Maui U.S.A.; an Invited Keynote Speaker for IEEE International Symposium on Intelligent Control, IEEE ISIC 2003 Houston U.S.A.; an Invited Keynote Speaker for LSMS 2007, Shanghai China; an Invited Expert Panelist for IEEE AIM2009; an Invited Plenary Speaker for IASTED RTA 2009, Beijing China; an Invited Keynote Speaker for LSMS 2010, Shanghai China; an Invited Keynote Speaker for IASTED CA 2010, Banff Canada; an Invited Keynote Speaker for IFTOMM ICDMA 2010, Changsha China; and an Invited Keynote Speaker for ICUAS 2011, Denver USA.