Research On Path Planning Of Laser Cladding Remanufacturing Robot For PDC Bit

Remanufacturing technology takes the repair technology as the means to repair the local surface of the used parts,so that the used products can be developed and used again.Laser cladding technology has been widely used in remanufacturing products with its advantages such as small heat affected zone,high bonding strength and easy precision control.Path planning has a direct effect on the repair quality of parts in the repair process of laser cladding robot.How to make a reasonable path planning for laser cladding robot and create a simple and efficient cladding repair path is an urgent problem to be solved.Based on the 3D point cloud data of the damaged PDC bit,the path planning method of the cladding remanufacturing robot was studied in this paper,and the quality inspection of the cladding repaired bit was carried out to verify the effectiveness of the method.The main research contents are as follows.1.For laser cladding repairing problem of the optimal process parameters selection,building cladding geometrical morphology characteristics(height,width)and process parameters(laser power,feeding rate and scanning speed),the relationship between the then based on the response surface method of central composite design(CCD)regression prediction model is established,through the analysis of variance test of significance,The relationship between the process parameters and the output response values,as well as the interaction between different process parameters were studied to guide the determination of the optimal process parameters,which laid a foundation for the realization of the optimal cladding path planning.2.The point cloud data of the damaged PDC bit is collected based on the blue ray 3D scanner.Combined with Boolean operation,the point cloud data of the damaged PDC bit is extracted from the point cloud data of the defect area.In order to achieve accurate data processing,point cloud library(PCL)is used for point cloud denoising.Aiming at the defective parts without original CAD data,the Eucluster-type clustering algorithm of point cloud database was applied to segment the defect surface to realize the extraction of the sag area,and finally the defect point cloud data needed for path planning was obtained.3.Combined with laser cladding process parameters and defect point cloud data,cladding path planning was carried out for the surface of defect area.The cladding path was obtained by point cloud slicing technique.Processing points were obtained by KD tree equidistant search algorithm.The normal vector is estimated by means of K neighborhood fitting point cloud data.Cubic B-spline was used to fit the processing points between the slice paths.Finally,the processing cladding path of point cloud data based on robot base coordinates is obtained.4.The laser cladding remanufacturing robot platform was used to carry out the physical cladding of the damaged parts and flat parts of the bit,and the quality inspection of the cladding repaired bit was carried out to verify the correctness and effectiveness of the point cloud data processing planning path.