Design And Characteristic Analysis Of Underwater Manipulator

The underwater manipulator is widely used in resource exploration and scientific research of underwater robots,and it is an important carrier to improve the efficiency of underwater robots.Based on the shortcomings of low efficiency,complex structure,high cost and poor versatility of light industrial underwater manipulators,this paper designs a modular underwater manipulator for small underwater robot sample collection and resource exploration,and its kinematics and hydrodynamics are analyzed and simulated.The main research contents are as follows:Firstly,according to the technical indicators and overall design scheme of the underwater manipulator,the structural design of the joints,claws and connecting parts of the module is completed;By calculating the maximum torque required by each joint,and the dynamic layout and detailed parameters of the module joints are determined.Using ANSYS Workbench to check the strength of the joint shell,output shaft and the manipulator under the maximum load,which verified the rationality of the material selection and structural design of the body;Through modal analysis,the natural frequency and mode characteristics of the manipulator are obtained,avoiding the resonance caused by the lower frequency of the underwater manipulator.Finally,the assembly of modular underwater manipulator prototype is completed.Then,the kinematics model of the underwater manipulator is established by D-H parameter method,and the MATLAB/Simulink model is built to verify the kinematics correctness.On this basis,the working space of the underwater manipulator is analyzed by Monte Carlo method.The results show that the parameters of the link and the range of joint rotation are set reasonably;The trajectory planning of the sampling motion process of the manipulator is carried out by using the five-degree multinomial interpolation method,which ensures the smoothness of the motion of each driving joint and provides a theoretical basis for the hydrodynamic simulation of the underwater manipulator.Finally,the hydrodynamic analysis and simulation of the underwater manipulator.Through the hydrodynamic analysis of the single link of the manipulator,the mathematical model of water resistance of underwater manipulator is established by Fluent software and Morsion equation,and the force of the water resistance on the manipulator link is simulated.By using ADAMS software to simulate the dynamics of the manipulator,the curves of kinetic energy and driving torque of each joint with time are obtained.The simulation results show that the running process of each joint is stable without large vibration,which meets the design requirements.The maximum driving torque of each joint under the influence of water environment factors is less than the driving torque calculated in Chapter 3,which proves that the joint dynamic layout and design of the underwater mechanical arm module is reasonable,which provides a basis for the manufacture of the mechanical arm prototype.