Research On Kinematics And Obstacle Avoidance Path Planning Of Super-redundant 9-dof Manipulator

The country's increasing attention to space science and technology has promoted the development of space technology,making the application of space station,space robot become a reality.And as its key technology-space manipulator also has a huge prospect,has been widely concerned.The second generation of the Canadian arm has attracted much attention because of its redundancy.Due to its advantages of high flexibility,strong structural interchangeability,good fault tolerance and high obstacle avoidance ability,its application in space has attracted more and more attention from researchers.It can not only be used to avoid singularity and obstacle avoidance in mission space,but also be used to minimize joint torque and energy consumption for specific tasks.At present,the redundant manipulator studied in the literature is mostly7 degrees of freedom,and this paper innovatively carries out in-depth research on the basis of 9 degrees of freedom super-redundant manipulator.Compared with the 7-dof manipulator,the 9-dof manipulator is more fault-tolerant.Even if one or two joints have problems during operation,it will not cause much impact on the working condition and can still continue to work.This paper mainly revolves around the following parts.Firstly,this paper introduces the characteristics of nine-free arm redundancy,analyzes the development status of tandem arm and obstacle avoidance path planning at home and abroad,summarizes the key technologies of tandem arm,and analyzes the development trend of tandem arm.Based on 9 degrees of freedom in series arm,has established the mechanical arm is inverse kinematics model and the obstacle model,detailed introduces the coordinate system,the transformation matrix transformation,connecting rod,lay a foundation for robot kinematics described,separately the mechanical arm is solution of the inverse kinematics,and by using Matlab Toolbox of Robotics are inverse kinematics simulation Toolbox.Then,a corresponding error model is established for the static pose accuracy of the manipulator.The main research method is the transfer matrix method.Then monte carlo method is used to measure whether the pose precision of the end of the manipulator meets the requirements of the index.On the basis of meeting the requirements of the index,the workspace of the nine-dof tandem manipulator isstudied.Finally,an improved algorithm,intree_RRT(save the initial tree),is proposed based on the bi_RRT(double tree rapid expansion random tree)algorithm.In other words,a complete barrier-free path is saved before the search tree is created,and then the obstacle avoidance of the 9-dof arm is studied.Firstly,the forward and inverse kinematics model and obstacle model are established.Then the bi_RRT algorithm and the improved algorithm are used for obstacle avoidance simulation test respectively in the 2-d planar robot and the 9-dof super-redundant arm.Simulation tests show that the improved algorithm is more efficient than the traditional algorithm in high dimensional space.The simulation results show that the average iteration time of the improved algorithm is shortened from one hour to ten minutes.