Research On Teleoperation Force Feedback Control Of Underwater Manipulator Based On Virtual Environment

The oil and natural gas resources in the sea are rich,huge reserves and valuable to exploit.The construction of underwater robot teleoperation system can greatly improve the operating efficiency of offshore petroleum gas resources exploitation.Underwater robots can replace divers to complete seabed exploration,cable cutting,underwater salvage and other tasks.The introduction of virtual reality technology can increase the visual presence of the operator,and the application of force presence technology to the teleoperation control system can make the underwater robot complete the underwater task more accurately,which has a high application value.In this thesis the kinematics,dynamics,control structure,control algorithm and virtual environment platform simulation of the teleoperation system of the underwater manipulator are studied in detail in order to improve the stability and transparency of the teleoperation system of the underwater manipulator.The main research contents are as follows:Firstly,according to the structural characteristics of the underwater manipulator,the linkage coordinate system of the underwater manipulator was established by using the improved D-H construction system method,and the forward and inverse kinematics of the underwater manipulator was deduced in detail.The simulation was verified on the MATLAB platform,and the working space of the manipulator was drawn by Monte Carlo method.The Lagrange method is used to analyze the dynamics of the underwater manipulator,and the hydrodynamics of the underwater manipulator is studied.The calculation methods of the water resistance moment,inertia moment and floating moment are introduced.Finally,the dynamics equation of the underwater manipulator is deduced.Secondly,in order to solve the problems of uncertain dynamics model and external interference such as ocean current in the teleoperation control system of underwater manipulator,two control strategies are proposed.One is a new bilateral impedance control strategy.By using the function approximation technique with error estimation to approximate the unknown external interference of the slave,the adaptive updating law is designed to estimate the model parameters of the master-slave manipulator online,and the estimation error is suppressed by the robust term,so as to realize the synchronous tracking of the master-slave manipulator force and position.The effectiveness of the control algorithm is verified by simulation on MATLAB/Simulink platform.The other control strategy is the hybrid control structure of force feedback and position feedback.The master uses the gray predictive controller with error compensation ability combined with PID controller for hybrid control.The slave uses the fuzzy adaptive system to adjust the switching gain online and the sliding mode control law to design the algorithm.Through the simulation comparison experiment on MATLAB/Simulink platform,it is verified that the control algorithm can make master and slave have good force and position tracking ability.Finally,Unity3D engine and MATLAB co-simulation were used to build a virtual environment that based teleoperation simulation platform for underwater robotic manipulator.The modeling of master and slave robotic manipulator,underwater environment modeling,virtual environment underwater robotic manipulator modeling,UI interface setting and collision detection theory were introduced.The angle tracking ability of the master and slave robotic manipulator,the end force tracking ability of the slave manipulator,the trajectory tracking ability of the master and the slave manipulator in virtual environment were verified by the teleoperation simulation platform of the underwater robotic manipulator in virtual environment,and the virtual force feedback in virtual environment was simulated and analyzed.