Research And Simulation Of Hydraulic Underwater Manipulator In The Simulated Environment Of Deep Sea

With the continuous consumption of the land resources, human speed up the pace tothe development of the resources in the ocean. Underwater manipulator, as a component ofthe underwater work-system, plays an important role in exploring resource and rescue indeep sea.The international and domestic development of underwater manipulator is introducedfirst in this paper. Three-dimensional model of the hydraulic manipulator, which couldwork in the deep-sea simulation environment, is established and the type of drive of whichis selected according to the demand. The static loads of the manipulator are analyzed usingthe FEM software COSMOSWorks. The results show that strength could meet therequirements in the maximum load.The kinematics model is constructed by using the D-H method, obtaining the forwardkinematics solutions. Inverse kinematics is solved by using the counter transformationmethod. The methods of Monte-carlo and fixed step are respectively used to thesimulation of the workspace. The characteristics of these two methods are compared in thesimulation interface of MATLAB GUI in this paper.Electro-hydraulic position servo control system of the underwater manipulator isdesigned based on the analysis and research of the hydraulic system. Because themanipulator use the asymmetric cylinder as driving source, fundamental equations of thevalve controlled asymmetric cylinder system are deduced. The parameter of the hydraulicpower components is determined and the components are chosen by static design. Transferfunctions of the components are confirmed in the dynamic design, obtaining the transferfunction model of the electro-hydraulic position servo control system. The models ofelectro-hydraulic servo system of the arm and forearm are simulated under the simulationenvironment of the Simulink. The stability and frequency characteristic are analyzedaccording to the simulation results.The method of fuzzy PID is applied to the control system of the manipulator in thepaper at last. Compared with electro-hydraulic servo system using traditional PIDcontroller, the system which adopts the fuzzy PID controller shows more adaptive in the circumstance of the load disturbance. The electro-hydraulic servo system of theunderwater manipulator, which uses the fuzzy PID control method of the underwatermanipulator based on trajectory planning, is studied. The simulation results verify thefeasibility of the electro-hydraulic control method based on trajectory planning.