Research On Following Technology Of Follower Based On Leader-Follower Strategy

In the advanced equipment manufacturing industry,such as aviation,aerospace and high-speed railway,there are generally large-quality,large-size parts.Compared with single AGV,multi-robot system has higher carrying capacity,guidance performance,flexibility and intelligence.Aiming at the problem of multi-robot cooperative handling of large parts,this paper studies the following AGV motion control technology based on Leader-Follower strategy.Firstly,the multi-robot cooperative handling technology scheme based on Leader-Follower strategy is studied,and a two-degree-of-freedom bearing platform for connecting AGV with large components is designed,and a motion control technology framework for following AGV is proposed.The kinematics laws of a single Mecanum wheel are analyzed,and the forward and inverse kinematics models of the omnidirectional moving AGV of the Mecanum wheel are established.In the kinematics control link,two kinds of motion control tasks and control fusion methods following AGV are studied.On the one hand,based on the Leader-Follower control strategy,the Formation-keeping control problem of multi-AGV is studied.The Formation-keeping error model is established by the kinematics relationship,and the Formation-keeping control law is obtained by using the feedback linearization theory.On the other hand,based on the Backstepping method,the trajectory tracking technology following AGV is studied,and combined with the neurodynamic control method,the problem of sudden change of speed occurring at the initial tracking or turning time following AGV is solved.Secondly,according to the two motion controller models established,the control errors of trajectory tracking and formation keeping are taken as fuzzy inputs,and the weighted fusion of the above two motion control variables is carried out by using fuzzy logic reasoning to output the motion control variables following AGV.Then the angular velocity control of four Mecanum wheels is calculated according to AGV inverse kinematics model.Thirdly,the Lagrangian dynamic equation following AGV is established in the dynamic control link.Aiming at the uncertainties and external disturbances in the system operation,the adaptive sliding mode control based on disturbance observer is studied to compensate the gain of sliding mode switching term adaptively,so as to eliminate the chattering problem of control output.Finally,according to the practical application requirements,the omnidirectional tracking AGV system of Mecanum wheels for multi-robot cooperative handling was developed,and the experiment of visual guidance cooperative handling was completed in the laboratory environment.The experimental results validate the feasibility of the AGV-following motion control technology proposed in this paper.It effectively integrates the dual control objectives of Backstepping trajectory tracking controller and Leader-Follower formation controller.Following AGV can quickly,stably and accurately follow the AGV,and realize the coordinated handling of large components on straight and curve paths.