Position And Attitude Adaptive Control Of UUV Near Sea Surface Constraint

Unmanned Underwater Vehicle(UUV)has gradually become one of the effective marine exploration in marine environment and equipment,with the rapid development of ocean development in recent years.UUV often needs to be recovered to the support ship after completing certain marine missions.However,it is not always easy to be finished in UUV's working region because of the unpredictability of the sea situation.One of the methods to solve this problem is to make UUV track the trajectory of the support ship for some time to the appropriate region.While the motion control is very important technical support for autonomic recovery of under-actuated UUV,so it has some significant value in both theoretic and engineering application to research the motion control method aiming at the process of recovery.The paper is motivated by solving the problem of UUV recovery near sea surface autonomously.Based on such requirement,the control and motion characteristics of the tracking problems based on the trajectory planning that descripted by SA-PSO is carried out.The main contents of this paper are as follows:Fistly,through the analysis of the process that the movement submarine autonomously recovers the UUV is divided into the typical two stages: rendezvous and homing.The UUV can reach the recovery collection point by the water trajectory planning and trajectory tracking control.Then,UUV tracks the movements of mother submarine and back to the near of the docking mechanism.The six degrees of freedom kinematics and dynamics equations of motion of UUV are established,then the environment disturbance models of ship such as waves and currents environment are established.In addition,the added mass,hydrodynamic force(moment)and the restoring force(moment)are analyzed,and the thrust model and thrust allocation are given.Furthermore,the dynamic system properties are discussed.Secondly,introduce the basic theory of particle swarm optimization algorithm(PSO)Because the PSO algorithm has a slow convergence speed and is easy to drop into a local minimum,the SA is integrated into the PSO to effectively avoid the local minimum and improve evolutionary rate during temperature decreasing procedures.The experiment results demonstrate that the proposed algorithm is superior to original PSO algorithm.In this paper,I use the simulated annealing algorithm particle swarm optimization(SA-PSO)to obtain a collision free,optimal and satisfying the above constraints trajectory.The processes of the problem have characteristics of online execution,so UUV can online replan the trajectory when it detects the obstacles.The simulations of typical cases can verify the feasibility of the method.Next,according to the planned trajectory that is descripted by SA-PSO,I carry out the research about the trajectory tracking control of UUV,so that UUV cans track the trajectory to the collection point.In the tracking process,in order to satisfy the time and attitudes constraints,UUV must track the velocity state and position state of sea surface trajectory.Therefor,I built the partially linearized kinematic errors model and dynamic errors model of UUV in tracking processes.Aiming at underactuated error system,the water surface trajectory tracking controller is designed by using PID method and a nonlinear sliding mode adaptive compensation.The simulations of tracking the planned space trajectory can verith the feasibility of the controller.Finally,it is carried out in this paper that the research of the UUV's horizontal trajectory tracking method in the process of following the support ship back to port.This research provides important theoretical and technical supports for UUV finishing the water task mission and being recovered safely and reliably.Make sure that position and attitude adaptive control of UUV near sea surface constraint is accurate.