Optimization Design And Study On Water Hydraulic Flexible Manipulator

Conventional manipulator is composed of rigid parts whose adaptability to the environment is very poor.Flexible manipulator is very flexible and the environmental adaptability is very strong,but it is too flexible and difficult to model.Based on the analysis of the organization structure of the Octopus tentacles,a flexible manipulator is designed by replacing the longitudinal muscle of the Octopus tentacles with axial elongation artificial muscles.Then the manipulator is analyzed by using the finite element method,and the following research is mainly conducted in this paper:Firstly,the structure design of the flexible manipulator is carried out in this paper based on the tissue analysis of Octopus tentacles.It is found that the flexibility of Octopus tentacles originates from its four groups of longitudinal muscles,spiral muscle and transverse muscle.And the axial elongation artificial muscles are used to simulate the longitudinal muscles of Octopus tentacles,afterwards a flexible manipulator is designed which consists of three identical segments.Through the comparison and analysis of the two structures of the three-muscle joint and four-muscle joint,it is found that the three muscles has stronger bending ability and lighter quality.According to the actual situation,three-muscle segments are selected to form the flexible manipulator.Then,three-muscle joint is analyzed theoretically and the main working condition is selected.Secondly,the bending characteristics of joint are analyzed by simulation software,and the design is optimized.After that the 3-D model of flexible joint is obtained by using SolidWorks software,the influence of joint structural parameters on joint angle and axial elongation are studied by using Response surface optimization tool.Ant each joint structure parameter's sensitivities to joint angle and joint axial elongation is studied by Parameter Correlation module.Then,maximizing the joint angle and minimizing the axis elongation are taken as the optimization goals,the MOGA algorithm is used to optimize the joint structure parameters and three design schemes are obtained.Consequently the deformation analyses of the three design schemes under the action of gravity are analyzed respectively.Thirdly,the kinematic analysis and load capacity analysis of the manipulator are emplemented.Based on the hypothesis of piecewise arc,the kinematic equations of the manipulator are established by the homogeneous transformation matrix.Thus the forward kinematic equation is verified by the finite element simulation method,differential inverse kinematics is validated by MATLAB.Then the load capacityies of single joint,two joint and three joints manipulators are studied.Finally,based on the above analysis,the prototype of flexible manipulator is fabricated.The kinematic performance and the load capacity are experimentally analyzed by using water hydraulic comprehensive experimental system.