Research On Obstacle Avoidance Path And Trajectory Planning Of Six-degree-of-freedom Manipulator

Under the guidance of the “quality-first” basic policy proposed by “Made in China 2025”,China is in a critical stage of shifting from expanding quantity to improving quality,and robotic arms are gradually being widely used in various fields.However,there is still a large gap in practical application and core technology research and development compared with developed countries.Therefore,research on key technologies of robotic arms is increasingly receiving attention.Among them,path planning and time-optimal trajectory planning technology are hot topics in robotic arm research,which play an important role in the motion control of robotic arms.The text is about a research project that focuses on a six-degreeof-freedom robot arm called IRB120.The research includes studying the kinematics of the robot arm,obstacle avoidance path planning,and time-optimal trajectory planning.The main research results include:(1)The traditional D-H parameter method was used to construct the kinematic model of the IRB120 robotic arm,and the forward and inverse kinematics equations were solved based on the model.The correctness of the derived forward and inverse kinematics equations was verified using MATLAB Robotics Toolbox.The workspace of the robotic arm was also calculated using the monte carlo method,providing theoretical support for subsequent research on path planning and trajectory planning.(2)In the process of robotic arm path planning,an analysis was conducted on the collision detection problem that needs to be solved.Several commonly used bounding box methods were introduced.Cylindrical bounding was used to envelop the linkages based on the structural characteristics of the robotic arm,and rectangular bounding was used to envelop obstacles.The radius of the linkages was added to the bounding box of obstacles using a transformation and superposition approach,which simplified the collision detection problem to determining whether a line segment in the workspace intersects with the rectangular bounding box.This lays the foundation for subsequent obstacle avoidance path planning.(3)In terms of obstacle avoidance path planning,a series of improvement methods were proposed,including incorporating genetic algorithm,to address the shortcomings of the conventional ant colony algorithm in path planning in a three-dimensional workspace,and to enhance the overall performance of the improved ant colony algorithm.Construct a working environment model using the grid method,compare and validate two algorithms through MATLAB,and smooth the path of the improved ant colony algorithm using the cubic B-spline curve method to make the planned path more reasonable.(4)Using different interpolation algorithms in joint space and cartesian space,a trajectory planning method is developed for a sixdegree-of-freedom robot arm.The method includes a time-optimal 3-5-3 segmented polynomial interpolation using butterfly optimization algorithm to optimize interpolation time for obstacle avoidance path smoothed by cubic B-spline function,under the constraint of speed.The method is iteratively optimized using this approach,and MATLAB is used for simulation experiments.The results demonstrate that the method has fast convergence speed and good operational stability,showing its feasibility and superiority.