Research On Control System Method Of UVMS Based On Disturbance Observation

As an important tool to explore and develop the marine resources,the Underwater Vehicle Manipulator System(UVMS)is widely used in Offshore Oil Engineering,underwater salvage and other industries all over the world.However,in the complex underwater environment,the anti-interference ability of UVMS system has always been a hot research at present.Supported by the National Natural Science Foundation of China research project(51809128),this project designed and developed a kind of operational underwater vehicle system,and carried out research on key issues such as UVMS motion control and trajectory tracking control of underwater manipulator.The main content of this paper is as follows:Firstly,the overall structure and scheme of UVMS system are designed.The system mainly consists of four parts,ground control station,umbilical cord cable,underwater vehicle and underwater manipulator system.The design of key modules,hardware and software of control system are completed.Secondly,the mathematical modeling method of UVMS system is studied.The UVMS system is mainly composed of two subsystems,underwater vehicle and underwater manipulator.By analyzing the kinematics and dynamics of underwater vehicle,the mathematical model of 6-DOF is established and simplified,and the depth control model of UVMS is constructed.And then the mathematical model of underwater manipulator is established by using Lagrangian modeling method.At last the kinematics model of UVMS is established by coordinate transformation.Thirdly,the motion control of UVMS system is studied due to the complex and changeable characteristics of underwater disturbance.The ADRC algorithm is applied to the close-loop control of UVMS motion.It observes and compensates the total disturbance of system by extended state observer in real-time.The simulation results show that the system has stronger anti-interference ability and robustness which provides a good platform for the research on cooperation control of underwater manipulator system.Fourthly,the trajectory tracking control method of underwater manipulator is studied.Because the unknown external disturbance such as current will affect the trajectory of underwater manipulator,the nonlinear disturbance observer is introduced into the control system to predict and compensate the unknown disturbance accurately,and the trajectory tracking controller of the underwater manipulator is designed based on back stepping algorithm,and the effectiveness of this method is verified by simulation.Finally,the experiments of water pool and field lake are carried out on the UVMS system.The results show that the UVMS system has stable motion and good control ability.The underwater manipulator can grasp underwater targets accurately and quickly,which meets the expected design requirements.