Research On Motion Control For Underwater Manipulator Based On Terminal Sliding Mode

With the advances of ocean exploitation，underwater operation tasks are becomingincreasingly complex. Manipulator as an important tool for ocean exploitation, such asundersea salvage, exploration of marine resources, submarine pipeline laying andmaintenance and so on requires higher overall performance, so the research on motion controltechnology of underwater manipulator has important significance and practical values.This paper makes underwater manipulator motion control technology as the object ofstudy to summarize the present research situation of underwater manipulator and motioncontrol technology and develop the underwater manipulator control system, analyzes kineticsand dynamic, research the motion control algorithm and do control experiments and otherrelated work.This paper analysis domestic and overseas status of underwater manipulator system andmotion control technology, and summarize the research of underwater manipulator systemand main motion control’s algorithms as the base of the research on motion controltechnology of underwater manipulator.For the research of underwater manipulator motion control technology, this paper baseson the master-slave controlling mode develops the control system of underwater manipulator.By analyzing the requirements of manipulator motion control this paper confirms overall planof its control system, divides function modules and design hardware circuit of the everyfunction modules.In the process of designing hardware circuit, for electromagneticinterference and current fluctuations caused by the power circuit, this paper gives the way ofthe optical isolation, which can isolate digital circuit and analog circuit to decrease couplingrelationships. By analyzing the software system structure of its control system, this paperdivides the software system structure, explains the main task of every modules, and givesdetailed the flow chart.This paper analyses kinematics and dynamics and planes motion of the underwatermanipulator according to the actual needs.First proceeding from manipulator forwardkinematics, based on the way of Denavit-Hartenberg to establish equations of forwardkinematics, but, because of the reverse kinematics is more important than forward kinematics,so this paper establishes equations of reverse kinematics based on forwardkinematics;Second to establish the dynamics model of the underwater manipulator based onLagrange equations, this paper analyses the hydrodynamic effect and establishes thehydrodynamic model of the underwater manipulator. Last on the principle of trackingsmoothly and least time to design the track of the motion.On the base of the analysis of kinematics and dynamics, this paper does the research onmotion control technology of underwater manipulator. This paper designes Fuzzy-PIDcontroller on manipulator control and does simulation experiment, getted a conclusion: theFuzzy-PID controller has a low accuracy on the underwater manipulator controlling and a badability to self-adapt.This paper gives the self-adaptive terminal sliding mode control methodon that problem, which way introduces RBF neural network,and does simulation experiment.This paper makes the underwater manipulator as the experimental platform, doesexperiments of its control system to make sure its reliability and stability after long timeoperation. On that basis, this paper conducts experimental verification between the controlmethod of the self-adaptive terminal sliding mode and the Fuzzy-PID, and analyzes controlperformances of the two different ways. The results of the experiments show that the controlmethod of the self-adaptive terminal sliding mode has better self-adaptive capacity and higheraccuracy than Fuzzy-PID.