Research On The Path Planning Method Of Robot Autonomous Grinding Surface Based On Point Cloud Data

With the continuous development of national manufacturing technology and the continuous improvement of the degree of intelligence,the application of robot grinding technology is becoming more and more extensive.Compared with traditional manual grinding,the robot grinding posture is flexible,adaptable and high-quality grinding,which keeps workers away from harsh environments and high-intensity labor.Grinding path planning is the key technology of robot grinding.Most of the existing planning methods use manual teaching or offline programming using 3D models.The paths calculated by these methods have problems such as low accuracy,difficult positioning,and mismatch with the actual workpiece.In order to solve the above problems,this paper designs a set of robot selfgrinding surface plan,and builds a set of robot grinding experiment platform according to this plan;researches a set of robot grinding path planning method based on low-precision point cloud;integrates the path planning method into In the experimental platform,a set of robot autonomous grinding control and simulation system was developed,and the accuracy of the grinding path was tested through experiments and the feasibility of the autonomous grinding control system was verified.The main research contents and conclusions are as follows:(1)An experimental platform for autonomous robotic grinding based on point cloud data was built.A set of robot self-grinding surface plan is designed,and the whole platform is divided into three subsystems: robot system,point cloud acquisition system and constant force grinding system.Different precision requirements are put forward for each subsystem based on grinding requirements.The coordinate transformation relationship between the robot,the depth camera and the center of the grinding tool is determined by the hand-eye calibration method and the tool coordinate center calibration method,respectively,and a hand-eye collaborative experiment is designed to verify the feasibility of the platform.(2)A set of path planning methods for robotic autonomous grinding of curved surfaces based on low-precision point clouds are proposed.Firstly,a point cloud smoothing algorithm based on normal direction is designed to preprocess the point cloud to reduce the fluctuation error of the surface point cloud;The generation algorithm is used to calculate the original grinding path between the section plane and the point cloud.By comparison,the path point generation algorithm only accounts for 11.89%of the time consumption of the existing algorithm,which improves the calculation speed of the path point;again,A path step adaptive algorithm is developed to resample the original path,which recalculates the path point spacing according to the curvature change;finally,the attitude of the grinding tool in contact with the surface is determined according to the normal vector of each path point,and based on the material Removing the model optimizes the distance between adjacent paths,which solves the problem of planning grinding paths on low-precision surface point clouds.(3)A set of robot autonomous grinding surface control system and simulation platform was developed,and the planning accuracy of the grinding path was tested through experiments.The designed control system integrates the experimental platform and the grinding path planning method,and calls each function in the system in turn through the upper-layer software to control the grinding process.Based on this system,the robot grinding simulation function is developed,and the robot motion,surface point cloud and path are displayed on the simulation interface to achieve the effect of real-time monitoring of the grinding progress.Finally,based on this control system,the normal accuracy test experiment of the grinding path is completed.The experimental results show that the planned path error of the system is within-1 mm to 1 mm,which can meet the requirements of the entire grinding plan for the path accuracy,and also verifies the independent Feasibility of grinding control system.