Research On The Algorithms Of 3D Concrete Printing Path Optimization

3D concrete printing is an efficient,green,and sustainable way to build intelligently.In the printing process,the printing nozzle always follows the set running path to complete the printing of the predetermined component graphics,which leads to the situation of excessive idle strokes and low printing efficiency when printing some structural complex components.In view of the above problems,this paper carries out the research of 3D concrete printing path optimization algorithm as follows:(1)Aiming at the problem of how to convert the 3D concrete printing component model into a digital model that can be handled by the path optimization algorithm,a digital modeling algorithm for the 3D concrete printing process is proposed.First,the concrete components were modeled in Sketch Up software,and then sliced using Cura to obtain the sliced images.The model feature points in the sliced images are extracted using the edge detection algorithm and Harris corner point detection algorithm,and then the digital model is built based on the connection information between each feature point.The algorithm saves a lot of human resource costs for the path optimization step in the 3D concrete printing process and ensures the accuracy of digital model establishment.(2)Aiming at the problems of poor forming quality and long printing time of 3D concrete printing components with constant printing path width,a 3D concrete printing path optimization algorithm with constant path width is proposed in this paper.The algorithm searches for the maximum Euler-loop in the printing path multiple times to ensure that the printing nozzle traverses the entire printing path with as few heads-up as possible,and then applies the ant colony algorithm to find the shortest path for the printing nozzle to run between each Euler-circuit,and finally determines the printing path of the entire concrete component to reduce the number of printing nozzle head-up times and the idle strokes in the running path.experimental data show that the printing nozzle head-up times is reduced by up to 75%,and the idle strokes of the printing path is reduced by up to 39.9% when printing the same component with the 3D concrete printing path algorithm proposed by this paper.The experimental results show that the printing nozzle head-up times and printing path idle strokes have a very important impact on the forming quality and printing time of 3D concrete printing,and the algorithm in this paper has a significant improvement on the problems existing in the3 D concrete printing,it is provided an effective reference for optimizing the forming quality and printing time of concrete components with constant printing path width.(3)Aiming at the problems of poor forming quality and long printing time of 3D concrete printing components with variable width of printing path,a 3D concrete printing path optimization algorithm with variable path width is proposed.The algorithm uses system identification technology to fit the relationship model between printhead diameter,printhead loading speed,and print path width of concrete components;then it finds the central axis of the print path based on the skeleton extraction algorithm,solves the print path width based on the eight-neighborhood connectivity analysis algorithm,and finally solves the printing speed of different printing points based on the relationship model to reasonably arrange the whole printing process.The experimental results show that when processing 3D concrete printing components with variable printing path width,the printing error in the effective width range of the proposed algorithm is only 0%-7.5%,which can avoid repeated path printing and replacement nozzles,improve the forming quality of printed components,and shorten the printing time.