Research On Kinematics And Dynamics Of Soft Manipulator Based On Modal Methed

Inspired by muscle structures such as elephant nose,octopus arm and tongue,the soft manipulator developed based on bionics can extend,contract and bend along any point of its structure.Compared with rigid manipulator,it has the characteristics of high flexibility,complex environment adaptability and human-machine safety interaction.In order to play its good performance,the soft manipulator must move accurately and reliably.Therefore,it is very important to calculate the dynamic model accurately and efficiently,which is inseparable from the modeling and simulation analysis of kinematics and dynamics.In this paper,a kind of flexible manipulator with constant curvature bending and elongation is taken as the research object,and a modal method is used to study the kinematics and dynamics of the soft manipulator.The research focuses on the following aspects:Firstly,the kinematics of the plane soft manipulator is studied.In order to avoid the singularity and complex nonlinearity of the piecewise constant curvature method,a modal method is used to establish the kinematic equation of the soft manipulator with a single element,and the accuracy and advantages of the method and the kinematic characteristics are analyzed.Based on the modal kinematics of a single unit,the kinematics equation of the soft manipulator with multiple elements is derived,and the kinematic characteristics of the manipulator with multiple elements are further analyzed.Then,the kinematics of the space soft manipulator is studied.Based on the kinematic analysis of plane soft manipulator by modal method,the modal kinematics model of the space soft manipulator with single unit is established,and its motion characteristics are analyzed in detail.On this basis,the modal motion of the multi element space soft manipulator is established.Furthermore,the motion planning of the multi-element planar and spatial soft manipulator is studied.For the plane motion planning,a distributed motion planning algorithm and particle swarm optimization algorithm are used to study the problem,and the advantages and disadvantages of the two are compared.In order to solve the problem of space motion planning,particle swarm optimization is used to study the effectiveness of the two algorithms.Different numerical simulation examples are used to simulate the effectiveness of the two algorithms.The simulation results show that the two algorithms are effective for different dimensions.Finally,the dynamic characteristics of the space soft manipulator are studied.The second kind of Lagrange equation is used to establish the dynamic equation of the soft manipulator.In the process of solving the mass matrix of the system,the soft manipulator is considered as a continuum with uniform distribution mass.Then,an equivalent centralized mass dynamics model based on the centroid is proposed,which places the concentrated mass at the position(centroid)matching the energy of the soft manipulator.The results show that the model takes into account the accuracy of Lagrange method and the efficiency of the centralized mass model.