Robot

International Journal of Control, Automation, and Systems (2010) 8(6):1288-1295 DOI 10.1007/s12555-010-0614-9

http://www.springer.com/12555

A Generalized Framework of Dynamic Role Assignment for Robot Formation Control

Yu-Cheng Chen and Yin-Tien Wang* Abstract: A dynamic role assignment algorithm is proposed in the paper for formation control of multiple mobile robots. The goal of the algorithm is to reassign a role for each robot automatically during a formation is forming or switching. Many formation control systems have been successfully implemented and validated by supporting experimental results. Nevertheless, this research aims at providing an efficient algorithm of role assignment for a class of formation control systems employing the concept of combinational optimization problems. Specifically, by exploring spatial relationship between robots and information of obstacles surrounding the robots, a character cost function is found to represent the degree of difficulty for a robot been assigned a specified role in a formation. Instead of using complex cost minimization procedure, a solution is provided by calculating the largest value of character set fitness, and a new formation is selected for robots accordingly. The developed algorithm is applied to the formation control of a group omni-directional driven robots. Simulation and experimentation are performed with real platform to verify the proposed algorithm and the results show that the performance of the proposed dynamic role assignment algorithm is efficient for robot formation control. Keywords: Dynamic role assignment, formation control, multi-agent system, obstacle avoidance.

1. INTRODUCTION There are many advantages for a robot team to keep a formation while moving. For example, only the leader of the robot team needs to perform the task of selflocalization, and the other robots obtain their own location by referring to the leader. Furthermore, it is a purpose of safety for a robot team...