Development And Control Of An Intervention AUV System

With the deepening of ocean exploration,an intervention underwater vehicle that can replace human for underwater exploration,collection and other tasks has become an important tool for marine development.The intervention underwater vehicle is equipped with a manipulator to form the underwater vehicle-manipulator systems(UVMS).The system has nonlinear,strong coupling,time-varying and high-dimensionality characteristics and its technology has become a research hotspot in the field of ocean engineering.Studying the coordinated control of the underwater vehicle and the manipulator is the key to achieving underwater autonomous operation of the UVMS.Taking the independently developed UVMS experimental platform as the research object,research work on modeling,control and experiment is carried out.A control strategy for solving the coupling problem between the underwater vehicle and the manipulator is proposed.And the stability of the position and the posture during underwater grabbing operation is realized in simulation and physical experiments.The specific contents and results are as follows:(1)Building an UVMS experimental platformBased on the PCE system architecture,a lightweight UVMS equipped with a two-degree-of-freedom manipulator and six thrusters is built for studying key technologies such as motion control and coordinated control.In addition,a corresponding simulation experiment platform is established for early design of the control algorithm.(2)UVMS system modelingKinematics and dynamics models of the underwater vehicle-manipulator systems are established.Furthermore,the dynamic characteristics of the underwater vehicle and the manipulator are analyzed,and the interaction between two parts is described.It lays a theoretical foundation for the subsequent control research.(3)Motion control of the underwater vehicleA sliding mode robust motion controller is proposed to achieve good tracking of the preset traj ectory in the still water.In order to overcome the disturbance such as smooth flow,an adaptive sliding mode robust controller based on RBF neural network compensation is proposed to improve the anti-interference ability of the underwater vehicle.The simulations and experiments demonstrate the performance of the above two controllers.(4)UVMS coordinated controlFor solving the forces/moments coupling between the underwater vehicle and the underwater manipulator,a sliding mode robust controller with the recursive adaptive compensation is proposed.This controller consists of a control item and a compensation item.The sliding mode structure of the control item has good anti-unknown disturbance performance.The compensation term is obtained by the Newton-Eulerian iterative equation of the manipulator and can adaptively compensate the disturbance of the manipulator to the vehicle.The simulation experiments of the grabbing operation and the physical experiments of the hovering swing are carried out successively,which prove that the algorithm can weaken the disturbance of the manipulator to the vehicle and improve the stability of the UVMS during operation,which has strong practicability.