Research On Containment Control Algorithm Of Underwater Vehicle Under Stochastic Environmental Disturbances

In recent years,with the continuous exploration and development of the ocean,Autonomous Underwater Vehicle(AUV)has gradually become an important tool in marine engineering.For some specific application scenarios such as submarine archaeology and oil exploration,it is necessary to deploy multiple underwater vehicles to perform containment control to increase the scope of work and complete the work efficiently.Containment control refers to that under the framework of a system with multiple leaders and followers,all followers eventually enter the convex hull formed by leaders’ trajectories through the guidance of all leaders.However,the stochastic characteristics of environmental disturbances make the research on the containment control of multiple underwater vehicles challenging.Based on the above problem,considering the stochastic environmental disturbances,this paper mainly studies the containment control problem of multiple underwater vehicles.The main work contents are as follows:(1)Aiming at the stochastic environmental disturbances,the trajectory tracking control problem of AUV is studied.Firstly,the stochastic environmental disturbances are divided into deterministic parts and stochastic parts,so the system model of AUV will be transformed into a stochastic nonlinear system form.Then,the adaptive law is designed by using adaptive method to deal with the influence acted on AUV by environmental disturbances.Based on this,an adaptive tracking controller is designed for trajectory tracking control of AUV.In addition,the stability of the designed controller is analyzed by constructing Lyapunov function.Finally,the simulation shows the effectiveness of the designed controller.(2)Considering the stochastic environmental disturbances,the containment control problem of multi-AUV is extended to study,and the situation of AUV with state constraints is also considered.The containment errors of AUV caused by environmental disturbances are compensated by adaptive method.Then,combined with the dynamic surface error method,a distributed finite-time containment controller is designed to enable the system to realize finite-time containment control,in which a state-based nonlinear function is introduced to deal with the state constraint problem.In addition,the stability of the designed controller is analyzed,which provides sufficient conditions for the bounded stability of the system in finite time.(3)For the case that the velocities of AUV are unmeasurable,the containment control problem of multiple AUVs under random environment disturbance is further studied.Firstly,the coordinate transformation of the multi-AUV system model is performed to construct a terminal sliding mode velocity observer to observe the velocities.Then,according to the estimated velocity information,a distributed adaptive containment controller is designed by combining dynamic surface error method and adaptive method,so that the follower AUVs converge to the convex hull formed by the trajectory of all leader AUVs.In addition,the stability of the proposed velocity observer and containment controller is proved by Lyapunov stability theory.Finally,the feasibility of the proposed control strategy is verified by simulation and experiment.