Distributed Output Regulation Control Of Multiple Robots Based On Topology

Multi-robot formation control is a system based on a single robot,through the communication of robots and the design of control algorithm to achieve the information sharing among robots and to achieve the desired formation.Although the performance of single robot continuously is improved,single robot cannot handle the situation facing a very complex environment which requires interaction of multiple robots.Therefore,the research on multi-robot cooperative control has become an important part of today's scholars.In this paper,the robot leader is virtualized and the formation control problem is transformed into the output regulation problem.The communication relation between the robots is described by the method of graph theory.The distributed control law is designed to realize the formation control of robots in the case of fixed topology and variable topology.The main work of this paper can be divided into the following four parts:Firstly,this paper introduces the theoretical basis of system stability and the Lyapunov method.The type of constraint is briefly introduced and by the constraints which the robot does not slip,it is concluded that the robot is subject to nonholonomic constraints.The dynamic model of the mobile robot is deduced and it is controllable according to the controllability theorem.The simulation platform MobileSim and the experimental robot AmigoRobot is described.Secondly,the implementation of multi-robot cooperative control is the basis of multi-robot control.The controller based on Lyapunov is designed by using the BackStepping controller design method and the Matlab simulation is carried out.The effectiveness of the algorithm is verified by simulation.By converting the coordinates into the Cartesian coordinate system,the tracker tracking and formation control based on the leader-follower feedback linearization controller are obtained.Thirdly,the defects of the BackStepping design method and the l-? controller are pointed out.Due to the shortcomings of these two methods,we propose a systematic distributed design method based on the virtual leadership.This method is a method of designing the controller which use the external trajectory as a virtual leader,the rest of the robot as a direct follower or indirect followers and apply graph theory to describe the communication relationship between multiple robots.The problem of tracking the virtual robot's trajectory is transformed into the output regulation problem.In the case of fixed topology,a distributed composite nonlinear feedback controller based on internal mode is designed to solve this output regulation problem.The derivation method of the controller is given and two methods of selecting the nonlinear part are described.Finally,because of considering the appearance of changing the topology in real life,the control under variable topology is studied.Setting the weight of the neighbor robot and the virtual leader is different and considering the father robot and child robot is not equal.The theory of multi-robot switching topology control is analyzed and the distributed dynamic feedback control law based on multiple inner membrane and observer is designed.The method of parameter selection is given.The example that the virtual leader and the three robots switched among the three topologies are displayed and the validity of the algorithm is verified by MATLAB simulation.