Distributed Formation Control of Multi-Robot Systems Using Potential Field Methods

• Main Authors: Yung-Lun Lin, 林雍倫
• Other Authors: Feng-Li Lian
• Format: Others
• Language: en_US
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/26922146879021380981

碩士 === 國立臺灣大學 === 電機工程學研究所 === 93 === The research topics of multi-robot systems have attracted much attention in recent years. Due to the ability of cooperation of robots, multiple robots can perform more difficult and complex tasks than one robot can perform. However, formation control problem is an important topic because multiple robots can perform tasks efficiently if the robots are in formation. Some specific formations can be formed by the multiple robots by planning trajectories of all robots. Moreover, when there are some obstacles in the real environment, the trajectories of the robots must be planned to navigate all robots for avoiding the obstacles and forming specific formations in the real environment. In the trajectory planning problems of multi-robot systems, potential field methods are used widely in the past. Artificial forces related to the potential field are used as the controllers of the robots. There are many kinds of the artificial forces proposed previously. One is the inverse power force. However, the coefficients of the inverse power force are designed intuitively in previous research. Moreover, there is another potential field method which is stream function method used to navigate a robot to avoid the obstacles in the environment. In this thesis, the trajectory planning problem of multi-robot systems is focused. The formations of multi-robot systems are defined firstly for the formation control problems. Secondly, the potential field methods and the artificial inverse power forces used in this thesis are defined. Thirdly, a case of three-robot system in is analyzed mathematically. There are two analysis methods used in thesis, that is, Lyapunov’s method and Linearization method. The convergence of these three robots is analyzed by Lyapunov’s method. The relationship between the stability of the formations which formed by these there robots and the coefficients of the artificial inverse power force are analyzed by the linearization method. The analysis results act as a design criterion when using inverse power forces in multi-robot systems. Moreover, the stream function method is combined with the artificial power forces to navigate these three robots to avoid obstacles and move to goal. Furthermore, some simulations demonstrate the analysis results in this thesis.