Research On Singular Point Avoidance And Trajectory Planning Of Six-axis Robot

With the State's Proposal of "Made in China 2025" vPlan,China's robotics and industry have developed rapidly.Robots are becoming the key equipment for enterprises in the production of products increasingly.At the same time,the functions of robots are becoming more and more strictly.Automatic obstacle avoidance and singularity avoidance in the process of robot motion have always been the research hotspots in the field of robotics.In the process of industrial robots'movement,obstacles often make it impossible to complete the established trajectory.At the same time,the singularity area is a specific area which can not be avoided by multi-joint serial robots,and it is extremely prone to production accidents in actual production.Based on obstacle avoidance and singularity problem,this paper has some theoretical research.The main research contents are as follows:(1)According to the content of the subject,the development status and trend of industrial robots at home and abroad are analyzed,and the research achievements and shortcomings of obstacle avoidance and singularity avoidance of robots are emphasized.On this basis,the necessity of further research on relevant theories of obstacle avoidance and singularity avoidance of robots is pointed out.(2)Taking the EFORT robot as an example,the corresponding parameters are obtained by the instruction manual,so the D-H parameter table of the robot is determined.The paper solves the forward and inverse kinematics of the robot,including the spatial transformation of the coordinate system of the robot and the relationship between the parameters of the link,and focuses on the analysis of the multi-solution problem in the inverse kinematics of the robot.This lays the foundation for the subsequent motion planning and singularity analysis of the robot.(3)For the robot obstacle avoidance problem,combined with the current extensive reinforcement learning algorithm in the field of trajectory planning,an intelligent algorithm based on Markov model and greedy decision is proposed.By selecting the appropriate state transfer function and reward function,a detailed flow chart of the algorithm is constructed.Then it enables the robot to achieve the basic obstacle avoidance purpose and also realize the shortest motion path.Finally,the 2D and 3D simulation of the robot is realized on the MATLAB software.(4)Aiming at the singular point problem of multi-joint serial robot,firstly,according to the D-H kinematics parameter table and the geometric parameters of the link,the velocity transfer relationship between the links is calculated,and that is the velocity conversion from the base coordinate system to the end coordinate system and the inverse solution calculation from the end to the base coordinate system.In this paper,Jacobian matrix is used to analyze the causes of singularities.Finally,a method of singularity avoidance based on Markov model is proposed.Through theoretical deduction and simulation verification,it is ensured that the robot can transition smoothly in the vicinity of the singular region.(5)The simulation platform of the robot is built,and the actual distance between the obstacle and the robot is calculated by the laser range finder.The algorithm is embedded in the controller.The simulation experiments of obstacle avoidance and singularity avoidance are carried out to verify the practicability of the algorithm.Finally,on the basis of this study,the possible research directions and methods in the future are discussed,and the author's own shortcomings in this paper are summarized.