Research On Biomimetic Rigid-Soft Hybrid Underwater Manipulator

At present,rigid robot has been widely used in all walks of life.However,its rigid structure cause it cannot adapt to various unstructured environments,and its security is poor when interacting with fragile objects.The fully soft robot has high flexibility and strong adaptability,but it has problems such as low carrying capacity and difficult modeling.In this context,based on the application of bionic technology in engineering practice,a new rigid-soft hybrid underwater manipulator is designed in this paper.The research is mainly carried out in the following aspects:Firstly,based on the method of combining BioTRIZ and Extenics,a radially deformable underwater rigid-soft hybrid manipulator is developed.Through demand analysis and looking up BioTRIZ contradiction matrix,the continuum animal snake is established as the biological prototype.Then,the biological coupling extension model is established according to the extension theory,and the similarity between the biological prototype and the biomimetic model is evaluated.For the deficiency of biomimetic design,TRIZ theory is used to optimize and improve biomimetic design.The designed manipulator is driven by water hydraulic artificial muscles,which is composed of soft components and rigid components.The manipulator not only has a certain flexibility,but also has a large carrying capacity.Secondly,based on geometric constraints and force balance constraints,the kinematics of the underwater rigid-soft hybrid manipulator without load and with load are analyzed.The static mathematical model of water hydraulic artificial muscle is established,and then based on the assumption of piecewise constant curvature,the forward and inverse kinematics model of the manipulator without load are established according to the geometric relation of the manipulator.According to the forward kinematics,Matlab software is used to solve the position and attitude of the end of the manipulator,and the workspace cloud map of the end of the soft arm is obtained.Then the static model of the manipulator with load is analyzed,the forward and inverse kinematics of the manipulator with load are solved by establishing the relationship between the force constraint and the geometric constraint,and the workspace of the manipulator with load is compared with that of the manipulator without load.Then,the Abaqus software are used to simulate the movement of the single artificial muscle and the whole manipulator.Using the modeling function of Abaqus software,the finite element simulation model of the single artificial muscle and manipulator are established.The single artificial muscle is simulated to analyze the influence of braiding angle and wall thickness on its shrinkage rate.Then,the whole manipulator is simulated without load and with load to analyze its motion characteristics.Finally,the experiments of water hydraulic artificial muscle and rigid-soft hybrid underwater manipulator are carried out.The static characteristics of the water hydraulic artificial muscle are tested.Then the load capacity of the manipulator is tested when it is bent,and the swallowing experiments and disgorging experiments of the manipulator are carried out in the upright and bending states,which verifies hat the manipulator has strong environmental adaptability and large carrying capacity.