讲座题目：Pseudo-Rigid Formation Design 

报告人：Li-Sheng Wang

时 间：8月18日（周四）上午9：30
地 点：力学楼316（三楼会议室）
主持人：刘才山（教授）

报告内容摘要：
     A virtual structure, called the pseudo-rigid formation, for a multi-agent system is presented in this talk. Under this framework, the position of each agent can be determined by the position of the geometric center (center of the group) and a homogeneous deformation gradient. The underlying configuration space becomes the product of the three dimensional real vector space and the general linear group , a twelve dimensional manifold. The design of the formation for a system with many agents moving in space can be then transformed into that of twelve system variables. It is shown that the objective function in the optimal design for collision avoidance and goal approaching can be represented in terms of the system variables and the initial configuration of the system explicitly. The optimal formation can be then obtained, which is allowed to translate, rotate, stretch, and shear. To illustrate the main idea, one design methodology is proposed. The multi-RRT is used to find a candidate path for the center of the group, and the virtual-potential method and the Bezier curve are applied to refine and smooth the path, respectively. As for the deformation matrix, the method of virtual potential function is also adopted. However, here the optimal potential function is designed so that the deformation is optimal. Both 2D and 3D design examples show that the proposed scheme is feasible and effective. With pseudo-rigid formation, not only the design can be easier to adapt to the environment containing densely distributed obstacles, but also the inherent formality is beneficial to communication and coordination between agents.

报告人简介：
     Prof. Li-Sheng Wang received the B.S. degree from National Taiwan University in 1983, and the M.S. and Ph.D. degrees from the University of Maryland, College Park, in 1987 and 1990, respectively, all in electrical engineering. From 1990 to 1991, he held a research and teaching position at the Department of Mathematics, University of Maryland, College Park. Since 1991, he has been with the Institute of Applied Mechanics, National Taiwan University, where he is currently a Professor. His research interests include nonlinear systems theory, geometrical mechanics, robotics, and navigation and control. He is a senior member of IEEE, and served as an Associate Editor for the IEEE Transactions on Automatic Control from 1998 to 1999. Since 2010, he serves as a committee member of the Aero-Astronautical Engineering Program in National Science Council (Taiwan)。