Research On Water Hydraulic Underwater Manipulator And Fuzzy PID Control

With the acceleration of the development process of ocean, research and application of underwater manipulator and other underwater operation are becoming increasingly important.With the complexity and control of autonomous underwater tasks requires continuous improvement, it put forward higher requirements of the autonomous operating capabilities and control capabilities. Underwater equipments work in a complex marine environment,such as random interference by ocean currents.Meanwhile, the non-linear performance of the underwater equipments have different to land-based equipment.Research on hydraulic manipulator and control technologies for improving the intelligence level and accelerating the practical process have important significance and practical values.This paper makes water hydraulic underwater manipulator as the object for study.Based on the basic hydraulic oil manipulator and motor-driven manipulator robot control method and considering underwater manipulator's requires,studied the water hydraulic drive system and hydraulic underwater manipulator control technology.Analyzing kinetics and dynamic,studied the motion control algorithm and carried out related control tests on the development of the test platform.This paper analysis domestic and overseas status of underwater manipulator system and motion control technology, summarized the research of underwater manipulator system and main motion control's algorithms as the base of the research on motion control technology of underwater manipulator.For the research of underwater manipulator motion control technology, this paper bases on the master-slave controlling mode develops the control system of underwater manipulator.By analyzing the requirements of manipulator motion control this paper confirms overall plan of its control system, divides function modules and designs hardware circuit of the every function modules.In the process of designing hardware circuit, for electromagnetic interference and current fluctuations caused by the power circuit, this paper gives the way of the optical isolation, which can isolate digital circuit and analog circuit to decrease coupling relationships. By analyzing the software system structure of its control system, this paper divides the software system structure, explains the main task of every modules, and gives detailed the flow chart.This paper analyses kinematics and dynamics and planes motion of the underwater manipulator according to the actual needs.First proceeding from manipulator forward kinematics, based on the way of Denavit-Hartenberg to establish equations of forward kinematics, because of the reverse kinematics is more important than forward kinematics ,so this paper establishes equations of reverse kinematics based on forward kinematics;Second to establish the dynamics model of the underwater manipulator based on Lagrange equations,this paper analyses the hydrodynamic effect and establishes the hydrodynamic model of the underwater manipulator. With the principle of tracking smoothly and least time design the tracking of the motion.Underwater manipulator systems are high accuracy, strong coupling parameter varying system,this paper designs a Fuzzy-PID controller on manipulator control.Based on the PID controller and using a two-dimensional fuzzy controller,the paper designs fuzzy PID controller. From the perspective of trajectory tracking capability, through simulation experiments on the effectiveness of fuzzy PID control method for verification, simulation results show that: Compared with PID control, fuzzy PID controller design has a higher regulation accuracy and faster response speed.This paper makes the underwater manipulator as the experimental platform, does experiments of its control system to make sure its reliability and stability after long time operation.The paper builds a water hydraulic system experimental platform for experiments,designs the hardware control circuit and writes software control systems. Motion control experiments were carried out on land and water, and analyzes the impact of the amplitude and frequency tracking trajectory tracking accuracy; the paper also carried out mechanical hand movement interference experiments, based on the experimental results analysis the manipulator control anti-jamming capability. Using PID controller and fuzzy PID controllers do experiments,and comparative analysis of the experimental results, the results verify the validity of fuzzy PID.