Motion Planning And Simulation System For Multi-section Continuum Robots

With the development of modern industrial production and technology,people have stricter requirements on the operating environment of robots.Traditional robots are limited to being manipulated in complex space environment due to their structural limitations.Continuum robots,as the new type of bionic robots,are more suitable to work in a restricted environment due to their excellent bending characteristics and passive compliance with constraints.In this paper,the research works on the multisection continuum robots are carried on in the context of the operation in a complex space environment.Firstly,based on the experimental platform of the multi-section continuum manipulator in our laboratory,the movement mechanism of cable-driven continuum robots is analyzed and the hypothetical conditions for the kinematics model of continuum robots are proposed.Next,the three spaces and mappings between them,including actuator space,configuration space,and task space of continuum robots,these spaces are analyzed with the spin theory and the exponential coordinates based on Lie group theory.Then the forward & inverse kinematics and differential kinematics algorithms of continuous robots are proposed.The MATLAB simulation experiments of space motion and endpoint trajectory tracking of the multi-section continuum robot are carried out by MATLAB,and the results verify the effectiveness of the kinematics model proposed previously.Secondly,a multi-point coordinated motion planning method is proposed for the motion planning problem for continuum robots in a complex space environment.In this method,the motion planning problem for continuum robots is divided into two subproblems: path planning and path following.In the path planning progress,based on the traditional artificial potential field method,the harmonic field of multiple obstacles is established according to the complex potential,so that the continuum manipulator's end-effector can be planned to have a collision-free path which is used as the reference path.In the path following progress,multiple special points on the manipulator are selected and the points on the reference path are regarded as sink points which update continuously as the manipulator approaching its target points.The sink points can ensure that the special point avoids the obstacle and reaches the target point safely.Through the kinematics constraints of the continuum robot,the method guides multiple special points to move coordinately,thereby ensuring that the whole continuum manipulator can complete the operation task in a complex space environment.The MATLAB simulation experiments of four-section continuum manipulator motion planning in a multi-obstacle environment are carried out,and the results show that the proposed multi-point coordinated motion planning method can effectively meet the requirements of motion planning tasks for continuum robots in a complex space environment.Finally,a multi-section continuum robot motion planning simulation system is designed by MATLAB GUI.Users can easily change the test parameters through the designed human-computer interaction interface to complete the experiment of endpoint trajectory tracking and motion planning for continuum manipulators in a complex space environment,which are shown in this paper.The changing curves of relevant parameters are given and the evaluation indicators are proposed in the system.