Research On Cooperative Formation And Obstacle Avoidance Algorithm For Multi-AGV Transport

As an important research direction in the field of multi-AGV system collaboration,the problem of multi-AGV system collaboration is widely used in many scenarios such as industry,life and military.Based on the multiple AGV collaboration fleet to carry large objects as application background,in view of the traditional multi-robot coordination in the process of the formation as a result of robot needs a large amount of data transmission between delay and communication the problem of the large amount of calculation,subtly introduction of visual identification bar code way to achieve the purpose of coordination between multiple robots formation.This thesis focuses on the study of multi-robot cooperative formation and obstacle avoidance,and gradually realizes the functions of multi-robot cooperative formation and obstacle avoidance.Firstly,the kinematics modeling of multi-robot system is carried out.Secondly,the formation control algorithm and obstacle avoidance strategy are studied.Finally,the formation control of multi-robot system is realized by using the navigation following mode with the help of visual recognition and location bar code.The main research contents are as follows:1.Build and design a multi-robot collaboration system platform.The experimental platform in this thesis is composed of three mobile robots.In this thesis,the most common triangle is taken as the formation formation for study.The pilot robot is one of the vertices in space,and the other two follow robots are the other two vertices.The distance Angle between the following robot and the pilot robot forms a formation together.The pilot robot is equipped with lidar and Kinect camera,and carries the bar code used to follow the robot to identify.The robot is followed by a visual system to identify the bar code and complete its own positioning.All the robots used were designed based on the open-source robot operating system(ROS),and the autonomous navigation of a single robot and the formation obstacle avoidance experiment of multiple robots were completed on the simulation software MATLAB and real objects.2.Multi-robot formation.In this paper,the pilot following formation mode based on virtual structure is adopted,which is different from the traditional formation control method.The formation is controlled by introducing barcode,which can reduce the influence of the pilot robot on the formation caused by the communication packet loss of the following robot.In this thesis,the visual system on the following robot is mainly used to identify the bar-code positions carried by the guiding robot,so as to confirm the relative positions of the guiding robot and the following robot,and the following robot can adjust its travel speed and direction with the obtained positions,so as to achieve the purpose of formation.3.Study on obstacle avoidance strategies of multiple robots.Since the application background of this thesis is to coordinate the handling of large objects by multiple robots,the original formation should not be changed as much as possible in the process of obstacle avoidance by multiple robots.For example,the triangular formation studied in this thesis can be completed by increasing or decreasing the alignment Angle between the pilot robot and the following robot according to the actual situation.But for the formation without load,the obstacle avoidance strategy is more flexible.In this thesis,isomorphic formation transformation and heterogeneous formation transformation are proposed to avoid obstacles.