A Study Of Interference Detection And Path Planning Of Industrial Robots

With the development of science and technology,the operational environment and tasks of industrial robots have become more and more complicated,and the requirements for the path planning of industrial robots are improved too.Therefore,the issue of interference detection of industrial robots in the process of movement has become an important part of robot path planning technology research.Based on the study of kinematics modeling of the robot,this thesis detects the working state of the robot by comparing the axial distance and the axial angle between the connecting link and the obstacle.On this basis,the Rapidly-Exploring-Random Tree(RRT)algorithm has been enhanced,and its stability has been improved too.The research applies it to path planning and achieves a preferable result.The specific research content includes the following aspects:Firstly,this thesis analyzes the related theories of robot kinematics further so as to get more information about the robot pose,coordinate transformation and so on.Taking the Motoman ES165 D robot as its research object,the study establishes D-H parameter model and solves the forward kinematics and inverse kinematics equations.Then,the thesis studies two methods of detecting the interference between robot linkages and obstacles.One is based on the distance between the axis to determine interference,the other is based on axial angle of obstacles and connecting links to detect interference.Both of the two methods turn the obstacle's position parameters into detection conditions to judge whether there is an interference condition or not.In this way,the accuracy of the interference detection is improved.In order to avoid the large and complex calculations in 3-dimension space,the robot links and obstacles are both simplified to cones or cylinders,and the plane projection is applied to translate the problems of 3-dimension interference detection into 2-dimension.As a result,the algorithm greatly reduces the computation complexity and notably improves the speed and efficiency of the operation.Next,to avoid the randomness,slow convergence,and non-optimal path of the traditional fast-expanding random tree algorithm,the study introduces the direction vectors,based on which,the selection of nodes is expanded.In this way,the leaf nodes gradually increases,so the randomness of the nodes reduces and speed of expansion improves.The simulation results show that the number of random nodes in the path of the improved RRT algorithm decreases,and the path obtained by the planning is better.Finally,the 3-dimension simulation test of the robot interferometric detection method and the improved RRT algorithm is completed with the Unity 3D software to intuitively present the process of the obstacle avoidance path planning of the robot under the improved RRT algorithm.