Distributed Coordinate Formation Control Of Nonholonomic Agents Using Relative Information

Coordinate control for multi-agent system(MAS)involves the subjects in mathematics,machinery,control theory,artificial intelligence and etc,which has been widely applied in related fields,e.g.,social service and military security.As an important part in the coordinate control researches for MAS,MAS formation control,of which objective is to make the whole agents achieve and maintain the desired formation shape along the moving trajectory,has drawn great attentions.There are two aspects in MAS formation control researches: the description of the MAS model and the information used for controller design.For the MAS model,the agent in nonholonomic unicycle-type has become popular,because its modeling process is close to the reality.Furthemore,the relative information has been widely used in MAS control,since it just consider the information obtained in the local coordinate frame without any global information,which can overcome the limitations of the global coordinate frame.Thus,in this thesis,it is valuable to study the formation control for nonholonomic unicycles with relative information.This thesis considers the distributed coordinate formation control for nonholonomic unicycle-type MAS and proposes a class of distributed controllers based on function S,using relative information,to solve three kinds of MAS formation control problems(R-type,T-type,combined-type).For the R-type,firstly,the general mathematical description of this problem is summarized,the core of which is the immobility of the target point and the rotation of the formation;then,using the relative information in the local coordinate system,a class of distributed controllers are proposed based on function S,while the global asymptotic stability is analyzed;finally,the effectiveness of the controllers is verified by numerical simulation,and the proposed controllers are compared with the existing literature to summarize the characteristics of these controllers.For the T-type,in the same way,the mathematical description is firstly summarized,the core of which is the movement of the target point and the translation of the formation;then a class of distributed controllers are proposed based on state observers using function S.In particular,when the target trajectory is circular,the proposed controller can degenerate to similar results to the R-type case.Also,the global asymptotic stability is analyzed,supporting by numerical simulation,and the characteristics of these controllers are summarized.For the combined-type,similarly,the mathematical description is summarized(the core lies in the movement of the target point and the rotation of the formation),a class of distributed controllers is proposed based on function S,similar to the R-type case,the global asymptotic stability is analyzed,the results are verified by numerical simulation,and finally the characteristics of these controllers are summarized.The main contributions of this thesis are: the relative information used in the controllers,the more general topology of MAS,and the global asymptotic stability of the system from the theoretical level,specifically:1.Propose a class of distributed controllers with function S,for three types MAS formation control problems,and prove the global asymptotic stability.Especially,for the T-type,consider a distributed controller based on the S-type state observer.2.Consider the relative information.Especially,for the R-type and combined-type,the relative information of the target can only be access to some agents,and other agents do not know the desired target.3.As for the communication topology,consider a weighted digraph,which is more general and makes sense.