Research On Multiple Autonomous Underwater Vehicle Recovery Coordinated Control Method

This study takes the marine recovery task as the application background,takes the autonomous unmanned vehicle(AUV)as the research object,and takes the coordinated and stable control of the multi-AUV recovery as the research purpose.Considering that there are various communication constraints in the multi-AUV recovery process,the dynamic recovery mother ship is used as the leader,and the other AUVs are used as the follower.The multi-AUV recovery problem is transformed into the leader-follower consistency coordinated control problem.The reco very coordination control model of multiple autonomous underwater vehicles under limited communication and the stability of the recovery system are analyzed.The coordinated control problem of multi-AUV recovery tasks,the key issues such as weak communication limitations,external disturbance limitations,vehicle information exchange and data processing capabilities limitations,and network attack limitations of recovery systems are studied and analyzed.In this study,based on the linear second-order integral model of the AUV,and based on the architecture and characteristics of the multi-AUV recovery system,a multiAUV coordinated control system based on accurate feedback linearization is constructed.The main research contents are as follows:Firstly,considering the time-varying time delay and channel instability problems of underwater acoustic communication during the recovery process,an exponentially consistent coordinated control method for multi-AUV recovery under time-triggered mechanism is proposed.We were considering communication’s time-varying time delay problem.The forward difference theory establishes a linearized second-order integral model of vehicle feedback under time-triggered mechanism.An exponentially consistent coordinated control method for multi-AUV recovery under fixed communication topology is proposed.The relevant lemmas such as graph theory,Lyapunov-Krasovskii theory,and matrix theory obtain sufficient conditions for the system to achieve stable convergence in the recovery mission.To further solve the problem of underwater acoustic channel instability,the Markov stochastic transformation topology is used to describe the communication topology.An exponentially consistent coordinated control method for multi-AUV recovery under switching communication topology is proposed simultaneously.The boundary conditions that multi-AUV can be stably recovered from the mother ship are obtained.The exponentially consistent controller gain that ensures the stable convergence of the system is obtained.Secondly,considering that external disturbances limit the system during the recovery process,and H∞ consistent,coordinated control method for multi-AUV recovery under timetriggered mechanism is designed.A linearized second-order integral model of the AUV feedback with external disturbance is established under time-triggered mechanism by using the forward difference theory.The time-varying time delay and channel instability conditions of underwater acoustic communication,the relevant lemmas of graph theory,LyapunovKrasovskii theory,and matrix theory are applied to the system under fixed communication topology and switching communication topology,respectively.Based on sufficient conditions for stable convergence,the gain of the H∞ consistent controller is established to ensure the tracking performance,stability,and convergence of the recovery system.Thirdly,considering the system communication burden and the data processing capability of the AUV,an event-triggered multi-AUV coordinated control method is proposed.Considering that all AUVs in the recovery process share an event-triggered function,a multiAUV coordinated control method with a centralized event-triggered mechanism under time delay is proposed.Controller gain constraints and the upper bound are on time delay.Each AUV to be sailed has its event-triggered function.A multi-AUV coordinated control method with a distributed event-triggered mechanism under the time delay condition is proposed,and a distributed event-triggered state is designed.The controller independently triggers events,executes control tasks,and solves the controller gain constraints that can ensure the stable convergence of the recovery system.The coordinated control algorithm based on the eventtriggered mechanism can effectively reduce the number of communication updates of the multiAUV system,thereby reducing the energy consumption.Finally,a distributed,event-triggered safety consistency coordinated control method is proposed considering the influence of DoS attacks and additional nonlinear factors on the vehicle during the recovery process.The recovery time is divided into the communication interval and the attack interval.A segmented Lyapunov function is constructed to obtain the sufficient conditions for the existence of the security consistency controller gain,analyze and establish the constraints of the attack frequency and attack duration of the DoS attack,and at the same time,exclude possible Zeno behavior during event firing.