力学系与湍流国家重点实验室学术报告5.24日上午两场报告(报告人 Stjepan Bogdan, Frank L. Lewis)
发布时间: 2011-05-19 05:20:00
SEMINAR SERIES
北京大学工学院 
力学与空天技术系
力学与空天技术系 湍流与复杂系统国家重点实验室
题目：Formation control in multi-agent systems
报告人 Stjepan Bogdan
University of Zagreb
摘要
Use of cooperative formation of agents enables achieving goals that would not be possible for single agent. The ability to achieve, maintain and change formation is one of the fundamental prerequisites for coordinated behavior. So far various approaches to formation control are proposed and used. They vary from stochastic to deterministic control, both, open loop and closed loop, decentralized and centralized. A variety of mathematical theories such as graph theory, game theory and dynamical systems theory are therein utilized. In this talk we present three approaches to formation control in multi-agent systems:
- fuzzy logic based control,
- artificial potential based control,
- grid-based control algorithm.
Fuzzy logic based approach represents a methodology for control and decentralized decision making in multi agent systems. Driving forces are described by the set of fuzzy logic rules that have been determined by fuzzy Lyapunov stability criteria. The second approach is based on the artificial potential function that characterizes potential of the entire formation, created by the set of the bell-shaped elementary potential functions. The special feature of the introduced potential function is its dependence on a control parameter that widens or, conversely, concentrates the bell-shape changing the effective range of interactions. Finally, grid-based control algorithm is based on abstracting the agent formation by a rectangular grid. We develop a coordination strategy that ensures collision-free transitions between arbitrarily defined formations. This coordination strategy is based on a well-established control design methodology for manufacturing systems. Group navigation is achieved by integrating a waypoint planner with a novel grid-based formation reconfiguration controller. The proposed hybrid architecture is capable of driving a group of agents through a cluttered environment, while maintaining specified formation constraints. We present simulation and experimental results verifying the validity of the proposed methodologies.
- fuzzy logic based control,
- artificial potential based control,
- grid-based control algorithm.
Fuzzy logic based approach represents a methodology for control and decentralized decision making in multi agent systems. Driving forces are described by the set of fuzzy logic rules that have been determined by fuzzy Lyapunov stability criteria. The second approach is based on the artificial potential function that characterizes potential of the entire formation, created by the set of the bell-shaped elementary potential functions. The special feature of the introduced potential function is its dependence on a control parameter that widens or, conversely, concentrates the bell-shape changing the effective range of interactions. Finally, grid-based control algorithm is based on abstracting the agent formation by a rectangular grid. We develop a coordination strategy that ensures collision-free transitions between arbitrarily defined formations. This coordination strategy is based on a well-established control design methodology for manufacturing systems. Group navigation is achieved by integrating a waypoint planner with a novel grid-based formation reconfiguration controller. The proposed hybrid architecture is capable of driving a group of agents through a cluttered environment, while maintaining specified formation constraints. We present simulation and experimental results verifying the validity of the proposed methodologies.
简历
Stjepan Bogdan received his Ph.D.E.E. in 1999, M.S.E.E. in 1993 and B.S.E.E. in 1990 at the University of Zagreb, Croatia. Currently he is an associate professor at the Faculty of Electrical Engineering and Computing, University of Zagreb. His main areas of interest are discrete event systems, intelligent control systems, and autonomous systems. He is a coauthor of three books and numerous papers published in journals and proceedings. He is a member of IEEE CSS Technical Committee of Intelligent Control and is appointed General Chair of 2012 IEEE Multi-conference on Systems and Control. He is Vice-President of Croatian Robotics Society. He serves as associate editor of IEEE Transactions of Automation Science and Engineering, Journal of Intelligent and Robotic Systems, Transactions of the Institute of Measurement & Control and Journal of Control Theory and Applications.
主持人：段志生 教授
时 间：5月24日（周二）上午10：00－11：00
地 点：力学楼434大教室
欢迎广大师生光临！
题目：Cooperative Control for Synchronization in Nature and Engineering
报告人 Frank L. Lewis
The University of Texas at Arlington
摘要
Distributed systems of agents linked by communication networks only have access to information from their neighboring agents, yet must achieve global agreement on team activities to be performed cooperatively. Examples include networked manufacturing systems, the global aircraft routing system, wireless sensor networks, networked feedback control systems, and the internet. Sociobiological groups such as flocks, swarms, and herds have built-in mechanisms for cooperative control wherein each individual is influenced only by its nearest neighbors, yet the group achieves consensus behaviors such as heading alignment, leader following, exploration of the environment, and evasion of predators. It is known that groups of fireflies and of crickets align their frequencies, neurons in the brain fall into patterns of interacting burst phenomena, and biological groups fall into the circadian rhythm. It was shown by Charles Darwin that local interactions between population groups over long time scales lead to global results such as the evolution of species.
This talk explores the structure of complex distributed naturally occurring and human engineered systems. We review the basic sorts of graphs including random, small world, and scale free. It is shown how these notions can be used to design cooperative control systems for dynamical systems interacting on communication graph topologies. The fundamental ideas behind cooperative control for networked interacting teams are presented, including the graph Laplacian matrix, Fiedler eigenvalue, time to consensus, and consensus values reached. Discussed are local voting protocols, second-order consensus, control of systems in formations, and synchronization of distributed interacting oscillators. Local protocols based only on interactions between neighbors lead to global optimal behavior of distributed teams. Results from graph theory show the importance of the communication structure on the agreement reached by the networked team.
简历
Frank L. Lewis, Fellow IEEE, Fellow IFAC, Fellow U.K. Institute of Measurement & Control, PE Texas, U.K. Chartered Engineer, is Distinguished Scholar Professor and Moncrief-O’Donnell Chair at University of Texas at Arlington’s Automation & Robotics Research Institute. He obtained the Bachelor's Degree in Physics/EE and the MSEE at Rice University, the MS in Aeronautical Engineering from Univ. W. Florida, and the Ph.D. at The Georgia Institute of Technology in Atlanta. He works in feedback control, intelligent systems, distributed control systems, and sensor networks. He is author of 6 U.S. patents, 216 journal papers, 330 conference papers, 14 books, 44 chapters, and 11 journal special issues. He received the Fulbright Research Award, NSF Research Initiation Grant, ASEE Terman Award, Int. Neural Network Soc. Gabor Award2009, U.K. Inst Measurement & Control Honeywell Field Engineering Medal 2009. Received Outstanding Service Award from Dallas IEEE Section, selected as Engineer of the year by Ft. Worth IEEE Section. Listed in Ft. Worth Business Press Top 200 Leaders in Manufacturing. Received the 2010 IEEE Region 5 Outstanding Engineering Educator Award and the 2010 UTA Graduate Dean’s Excellence in Doctoral Mentoring Award. He served on the NAE Committee on Space Station in 1995. Has served as Visiting Professor at Democritus University in Greece, Hong Kong University of Science and Technology, Chinese University of Hong Kong, City University of Hong Kong, National University of Singapore, Nanyang Technological University Singapore. He is an elected Guest Consulting Professor at South China University of Technology and Shanghai Jiao Tong University. Founding Member of the Board of Governors of the Mediterranean Control Association. Helped win the IEEE Control Systems Society Best Chapter Award (as Founding Chairman of DFW Chapter), the National Sigma Xi Award for Outstanding Chapter (as President of UTA Chapter), and the US SBA Tibbets Award in 1996 (as Director of ARRI’s SBIR Program).
主持人：段志生 教授
时 间：5月24日（周二）上午9:00－10:00
地 点：力学楼434大教室
欢迎广大师生光临！