Research On Obstacle Avoidance Path Planning Of 6-DOF Industrial Robot

Industrial robots have played an important role in the transformation of modern manufacturing,and have gradually become an irreplaceable role in industrial production by relying on their high efficiency and high precision characteristics in production.Robotic obstacle avoidance path planning has always been the research focus of scientific researchers.This article uses the six-freedom industrial robot as the research object,explore its obstacle avoidance path planning method,proposes a planning APF-RRT algorithm to plan the obstacle avoidance path of the robot,and conduct simulation to verify the algorithm.The main research content in this article is as follows:(1)Kinematic analysis of the robot.The improved D-H method was used to establish the coordinate system of connecting rod,and the forward kinematics equation of the robot was derived.Combined with the wrist and arm separation method,an inverse kinematics optimization algorithm was proposed.Aiming at minimizing the rotation Angle,a group of joint angles with the minimum dinorm difference from the initial joint Angle was selected as the optimal joint Angle,and the robot was analyzed when it was in the singular configuration.MATLAB software is used to establish the robot model,and the forward and inverse kinematics of the robot are verified.The Monte Carlo method is used to plot the robot’s workspace.(2)Processing of visual information and analysis of collision detection.After selecting the depth camera,the camera is calibrated for intrinsic and hand-eye parameters to eliminate camera acquisition errors and obtain the pose relationship between the camera and the robot base.Through filtering algorithm,radius filtering algorithm and voxel filtering algorithm were used to process and optimize the point cloud information collected by the camera,and octree map was established by using the point cloud information to obtain the environment information of the robot working space.According to the robot structure characteristics,the robot structure is abstracted into multiple line segments,and the radius is superimposed on the obstacle,and finally the collision detection is realized.(3)An improved APF-RRT algorithm for obstacle avoidance path planning is proposed.The distance factor was introduced to modify the APF potential field function,and the IRRT algorithm was switched when the local minimum value was reached.IRRT algorithm introduced the bilateral nearest node selection method,proposed a new node secondary expansion method,and used target bias guidance method,cone subset constraint sampling and target guidance mixed strategy for path expansion.The APF-RRT algorithm was improved by combining IAPF and IRRT algorithm to detect the redundancy of the searched paths and remove the redundant nodes.The path is smoothed using tertiary non-uniform rational B-spline curves.The simulation results show that the improved algorithm takes shorter time and better path.(4)Simulation verification is conducted using the ROS system.The robot model was built according to URDF format and imported into the ROS platform.Then the visual information processing and obstacle avoidance path were verified.The simulation results proved that the path planned by the improved algorithm is feasible.