Research On Formation Coordination And Control Of Mobile Multi-robot System

Multi-robot system(MRS)is more efficient than a single robot in the face of complex tasks with high degree of parallelism and real-time performance due to its inherent distributed characteristics.It have been gradually applied to military investigation,cargo handling and automated warehouses,etc.The study of MRS has important research significance and it has broad application prospects.Among the researches of MRS,a well-attended and basis topic is the formation control of MRS.Based on the previous studies,the research of multi-robot formation control algorithm and system implementation has been presented.The main works are as follows:1.The background and significance of multi-robot system is introduced.The basic problems of multi-robot formation control are proposed in this paper.The current research status and methods of multi-robot formation control are summarized.2.Aiming at the problem of multi-robot system formation generating,a novel formation planning method based on virtual structure optimization model is proposed.The corresponding nodes of the virtual formation are optimized by designing a evolutionary algorithm and distribution method.Then a simple artificial potential is designed.The field completes the collision avoidance of the robot when reaching the corresponding node to form the desired formation.The MATLAB simulation proves that this method can make the robots with random distribution quickly form the target formation with the least energy consumption.3.A formation coordination based on flocking law is designed,which includes a smooth artificial potential function to maintain the desired distance between robots and a coherence protocol which completes the speed matching between robots.In the case of obstacle avoidance,the concept of "virtual robot" is introduced,the control method for smooth obstacle avoidance of robots is designed by imitating the interaction between robots.The simulation proves that the formation control can maintain stability and adaptability in the presence of interference such as target changing and obstacles in the environment.4.For the problems of MRS formation experiment using physical robots,the construction of the mobile robot hardware platform was completed.Under the framework of ROS(robot operating system),the control process has been designed.It including the motion input conversion from “particle” to mobile robot,wheel speed calculation,odometry and neighbor robots identification based on feature extraction.The stability and effectiveness of the algorithm are verified by the straight and steering motions of the three robots maintaining the equilateral triangle formation.