Research On Efficient Combined Slicing And Composite Path Planning Algorithm For Wire Arc Additive Manufacturing And Its Software Development

Wire and Arc Additive Manufacturing(WAAM)technology is based on the welding process,which involves data preprocessing,slicing,and path planning of the model,and generates instruction information files that can be recognized by the WAAM system to drive the WAAM equipment to melt metal wires point by point,line,and surface,ultimately achieving rapid stacking and manufacturing of parts.Compared to laser and electron beam additive manufacturing,WAAM is particularly suitable for manufacturing large and mediumsized metal complex structural components due to its high deposition efficiency,low manufacturing cost,and short production cycle.Therefore,it has broad application prospects in industries such as aerospace,transportation,and construction.Slicing and path planning are key steps in data processing of WAAM models.The rationality of algorithm design directly determines the efficiency of model data processing,affects the surface forming accuracy and quality of parts,etc.Therefore,it is urgent to design efficient slicing and path planning algorithms that comply with WAAM technology for complex topology models with large number of patches.This article conducts in-depth research on efficient slicing and path planning algorithms for complex models,and the main tasks completed are as follows:(1)Corresponding reading algorithms have been designed for the two file formats of the STL model.Homogeneous coordinates are used to represent spatial points,vectors and matrices,and the translation,rotation and scaling function functions are encapsulated to realize the spatial geometric transformation of the position,size,etc.of the STL model.The data visualization of STL model is realized based on VTK.Compared with Matplotlib visualization method,it is more efficient,interactive and can clearly show the texture of the model.(2)A layer height matching algorithm based on interpolation search is proposed,which can quickly find and match the intersection planes with STL model facets in the slice height list.Compared with traditional layer height matching algorithms,the algorithm can save more than43.28% time when the number of model facets and slice layers is large.By constructing a connection point data structure,a line segment concatenation algorithm based on dictionary key value pairs has been implemented.Compared with traditional algorithms,the efficiency of scattered line segment concatenation is significantly improved when the number of model facets and slice layers is large.Combined with the layer height matching intersection algorithm based on interpolation search and the line segment splicing algorithm based on dictionary key value pair,an efficient combined slicing algorithm of STL model is realized.Compared with the traditional algorithm,the algorithm can quickly and accurately generate the slice contour of each layer of the model,and the algorithm time saving rate is 90.04%.(3)In response to the computational complexity and poor robustness of traditional path planning algorithms caused by path self-intersection and mutual-intersection,various Boolean clipping and filling functions of the Clipper library were used to implement the global continuity contour offset path planning algorithm and zigzag path planning algorithm for the STL model slice layer.When the number of model facets and slice layers is large,the former algorithm runs in less than 100 seconds,the latter only takes 10 seconds.Subsequently,combining the advantages of high boundary restoration degree of contour offset path and high efficiency of zigzag path algorithm,a composite path planning algorithm for WAAM was implemented based on the weld bead width size and optimal lap spacing of WAAM.The filling direction and number of zigzag paths were optimized,and the algorithm was finally tested.The results showed that the algorithm can generate a composite path covering the entire slice layer of the STL model,The boundary restoration degree of the path and the filling density inside the slice layer are good,and the algorithm efficiency is high.(4)Based on the STL model reading and visualization algorithm,the efficient combined slicing and composite path planning algorithms mentioned above,a WAAM model data processing software was developed by using Qt Designer and Py Qt6.To verify the effectiveness of the software,a three factor and three level experimental method was used to obtain weld beads with good morphology,stable height and width dimensions.Based on the optimal overlap spacing between weld beads,the model was sliced and path planned using the developed software,and a path instruction file for a certain layer was exported.Finally,the feasibility of the software was verified through WAAM stacking experiment.