This study explores the influence of infill patterns on machine acceleration prediction in the realm of three-dimensional(3D)printing,particularly focusing on extrusion technology.Our primary objective was to develop ...This study explores the influence of infill patterns on machine acceleration prediction in the realm of three-dimensional(3D)printing,particularly focusing on extrusion technology.Our primary objective was to develop a long short-term memory(LSTM)network capable of assessing this impact.We conducted an extensive analysis involving 12 distinct infill patterns,collecting time-series data to examine their effects on the acceleration of the printer’s bed.The LSTM network was trained using acceleration data from the adaptive cubic infill pattern,while the Archimedean chords infill pattern provided data for evaluating the network’s prediction accuracy.This involved utilizing offline time-series acceleration data as the training and testing datasets for the LSTM model.Specifically,the LSTM model was devised to predict the acceleration of a fused deposition modeling(FDM)printer using data from the adaptive cubic infill pattern.Rigorous testing yielded a root mean square error(RMSE)of 0.007144,reflecting the model’s precision.Further refinement and testing of the LSTM model were conducted using acceleration data from the Archimedean chords infill pattern,resulting in an RMSE of 0.007328.Notably,the developed LSTM model demonstrated superior performance compared to an optimized recurrent neural network(RNN)in predicting machine acceleration data.The empirical findings highlight that the adaptive cubic infill pattern considerably influences the dimensional accuracy of parts printed using FDM technology.展开更多
Large-scale simulation optimization(SO)problems encompass both large-scale ranking-and-selection problems and high-dimensional discrete or continuous SO problems,presenting significant challenges to existing SO theori...Large-scale simulation optimization(SO)problems encompass both large-scale ranking-and-selection problems and high-dimensional discrete or continuous SO problems,presenting significant challenges to existing SO theories and algorithms.This paper begins by providing illustrative examples that highlight the differences between large-scale SO problems and those of a more moderate scale.Subsequently,it reviews several widely employed techniques for addressing large-scale SOproblems,such as divide-and-conquer,dimension reduction,and gradient-based algorithms.Additionally,the paper examines parallelization techniques leveraging widely accessible parallel computing environments to facilitate the resolution of large-scale SO problems.展开更多
In this paper, a vibration motion control is proposed and implemented on a foamed polystyrene machining robot to suppress the generation of undesirable cusp marks, and the basic performance of the controller is verifi...In this paper, a vibration motion control is proposed and implemented on a foamed polystyrene machining robot to suppress the generation of undesirable cusp marks, and the basic performance of the controller is verified through machining experiments of foamed polystyrene. Then, a 3 dimensional （3D） printer-like data interface is proposed for the machining robot. The 3D data inter- face enables to control the machining robot directly using stereolithography （STL） data without conducting any computer-aided man- ufacturing （CAM） process. This is done by developing a robotic preprocessor that helps to remove the need for the conventional CAM process by directly converting the STL data into cutter location source data called cutter location （CL） or cutter location source （CLS） data. The STL is a file format proposed by 3D systems, and recently is supported by many computer aided design （CAD）/CAM soft- waxes. The STL is widely used for rapid prototyping with a 3D printer which is a typical additive manufacturing system. The STL deals with a triangular representation of a curved surface geometry. The developed 3D printer-like data interface allows to directly control the machining robot through a zigzag path, rectangular spiral path and circular spiral path generated according to the information included in STL data. The effectiveness and usefulness of the developed system are demonstrated through actual machining experiments.展开更多
Large-scale cooling energy system has developed well in the past decade.However,its optimization is still a problem to be tackled due to the nonlinearity and large scale of existing systems.Reducing the scale of probl...Large-scale cooling energy system has developed well in the past decade.However,its optimization is still a problem to be tackled due to the nonlinearity and large scale of existing systems.Reducing the scale of problems without oversimplifying the actual system model is a big challenge nowadays.This paper proposes a dimension reduction-based many-objective optimization(DRMO)method to solve an accurate nonlinear model of a practical large-scale cooling energy system.In the first stage,many-objective and many-variable of the large system are pre-processed to reduce the overall scale of the optimization problem.The relationships between many objectives are analyzed to find a few representative objectives.Key control variables are extracted to reduce the dimension of variables and the number of equality constraints.In the second stage,the manyobjective group search optimization(GSO)method is used to solve the low-dimensional nonlinear model,and a Pareto-front is obtained.In the final stage,candidate solutions along the Paretofront are graded on many-objective levels of system operators.The candidate solution with the highest average utility value is selected as the best running mode.Simulations are carried out on a 619-node-614-branch cooling system,and results show the ability of the proposed method in solving large-scale system operation problems.展开更多
The objective of the work is to determine the influence of the PLA melting temperature during 3D printing on the dimensional accuracy of the model parts. Two modular drilling devices were also made using PLA model par...The objective of the work is to determine the influence of the PLA melting temperature during 3D printing on the dimensional accuracy of the model parts. Two modular drilling devices were also made using PLA model parts. The model parts were 3D printed using FDM technology and the ZMorph 2.0 hybrid 3D printer. The accuracy of 3D printing of the model part influences the realization of modular devices. In recent years, technology has evolved a lot, and the need to have the most efficient manufacturing equipment has increased. This is the reason for the development of 3D printers using FDM technology for plastic parts. The software used by these 3D printers used in FDM technology is very sophisticated, as they allow the manufacture of very precise 3D prototypes, identical to the designed 3D model, through modern additive manufacturing techniques. The quality and mechanical strength of the prototypes obtained using 3D printers is very good. The materials used by the 3D printers manufactured by FDM are cheap and accessible. These 3D printers are used to make three-dimensional objects (gears, flanges, bearings, covers, casings, mechanisms, figurines, interior and exterior design elements, architectural models, medical models).展开更多
利用不同厚度的亚波长介质块实现0~2π的相位变化,并基于惠更斯人工电磁表面原理设计了工作于28 GHz通信频段的全介质电磁透镜,该电磁透镜的焦距与口径比（F/D）为0.15。通过3D打印制备该电磁透镜,并将其与基片集成波导（SIW）贴片天线...利用不同厚度的亚波长介质块实现0~2π的相位变化,并基于惠更斯人工电磁表面原理设计了工作于28 GHz通信频段的全介质电磁透镜,该电磁透镜的焦距与口径比（F/D）为0.15。通过3D打印制备该电磁透镜,并将其与基片集成波导（SIW）贴片天线进行集成,构造了超低剖面的宽带透镜天线。全波分析与实验测量结果显示该电磁透镜能够将原SIW贴片天线的增益提高7 d B左右,而将3 d B波束宽度减小到10°左右,同时该透镜天线系统还具有良好的低副瓣。展开更多
Printing short fibre/thermoplastic composites using the fused filament fabrication method sometimes creates a gap between print paths. In this study, the two-dimensional moving particle semi-implicit method for liquid...Printing short fibre/thermoplastic composites using the fused filament fabrication method sometimes creates a gap between print paths. In this study, the two-dimensional moving particle semi-implicit method for liquid simulation was applied to simulate the print-path fusion process. The three-dimensional movement of the nozzle was simulated using the sliding motion of the nozzle. The method was applied to the printing of short carbon fibre/polyamide-6 composites, and the simulation results were compared with those of experiments. The simulated results of the cross-sectional configuration agreed well with the experimental results. This will enable the optimization of printing process parameters thus reducing the gap between print paths.展开更多
文摘This study explores the influence of infill patterns on machine acceleration prediction in the realm of three-dimensional(3D)printing,particularly focusing on extrusion technology.Our primary objective was to develop a long short-term memory(LSTM)network capable of assessing this impact.We conducted an extensive analysis involving 12 distinct infill patterns,collecting time-series data to examine their effects on the acceleration of the printer’s bed.The LSTM network was trained using acceleration data from the adaptive cubic infill pattern,while the Archimedean chords infill pattern provided data for evaluating the network’s prediction accuracy.This involved utilizing offline time-series acceleration data as the training and testing datasets for the LSTM model.Specifically,the LSTM model was devised to predict the acceleration of a fused deposition modeling(FDM)printer using data from the adaptive cubic infill pattern.Rigorous testing yielded a root mean square error(RMSE)of 0.007144,reflecting the model’s precision.Further refinement and testing of the LSTM model were conducted using acceleration data from the Archimedean chords infill pattern,resulting in an RMSE of 0.007328.Notably,the developed LSTM model demonstrated superior performance compared to an optimized recurrent neural network(RNN)in predicting machine acceleration data.The empirical findings highlight that the adaptive cubic infill pattern considerably influences the dimensional accuracy of parts printed using FDM technology.
基金supported by the National Natural Science Foundation of China(Nos.72071146,72091211,72293562,and 72031006).
文摘Large-scale simulation optimization(SO)problems encompass both large-scale ranking-and-selection problems and high-dimensional discrete or continuous SO problems,presenting significant challenges to existing SO theories and algorithms.This paper begins by providing illustrative examples that highlight the differences between large-scale SO problems and those of a more moderate scale.Subsequently,it reviews several widely employed techniques for addressing large-scale SOproblems,such as divide-and-conquer,dimension reduction,and gradient-based algorithms.Additionally,the paper examines parallelization techniques leveraging widely accessible parallel computing environments to facilitate the resolution of large-scale SO problems.
基金supported by the Japam Society for the Promotion of Science(JSPS)KAKENHI(Nos.25420232 and 16K06203)
文摘In this paper, a vibration motion control is proposed and implemented on a foamed polystyrene machining robot to suppress the generation of undesirable cusp marks, and the basic performance of the controller is verified through machining experiments of foamed polystyrene. Then, a 3 dimensional （3D） printer-like data interface is proposed for the machining robot. The 3D data inter- face enables to control the machining robot directly using stereolithography （STL） data without conducting any computer-aided man- ufacturing （CAM） process. This is done by developing a robotic preprocessor that helps to remove the need for the conventional CAM process by directly converting the STL data into cutter location source data called cutter location （CL） or cutter location source （CLS） data. The STL is a file format proposed by 3D systems, and recently is supported by many computer aided design （CAD）/CAM soft- waxes. The STL is widely used for rapid prototyping with a 3D printer which is a typical additive manufacturing system. The STL deals with a triangular representation of a curved surface geometry. The developed 3D printer-like data interface allows to directly control the machining robot through a zigzag path, rectangular spiral path and circular spiral path generated according to the information included in STL data. The effectiveness and usefulness of the developed system are demonstrated through actual machining experiments.
基金supported by the Key-Area Research and Development Program of Guangdong Province(2020B010166004)Natural Science Foundation of China(52007066).
文摘Large-scale cooling energy system has developed well in the past decade.However,its optimization is still a problem to be tackled due to the nonlinearity and large scale of existing systems.Reducing the scale of problems without oversimplifying the actual system model is a big challenge nowadays.This paper proposes a dimension reduction-based many-objective optimization(DRMO)method to solve an accurate nonlinear model of a practical large-scale cooling energy system.In the first stage,many-objective and many-variable of the large system are pre-processed to reduce the overall scale of the optimization problem.The relationships between many objectives are analyzed to find a few representative objectives.Key control variables are extracted to reduce the dimension of variables and the number of equality constraints.In the second stage,the manyobjective group search optimization(GSO)method is used to solve the low-dimensional nonlinear model,and a Pareto-front is obtained.In the final stage,candidate solutions along the Paretofront are graded on many-objective levels of system operators.The candidate solution with the highest average utility value is selected as the best running mode.Simulations are carried out on a 619-node-614-branch cooling system,and results show the ability of the proposed method in solving large-scale system operation problems.
文摘The objective of the work is to determine the influence of the PLA melting temperature during 3D printing on the dimensional accuracy of the model parts. Two modular drilling devices were also made using PLA model parts. The model parts were 3D printed using FDM technology and the ZMorph 2.0 hybrid 3D printer. The accuracy of 3D printing of the model part influences the realization of modular devices. In recent years, technology has evolved a lot, and the need to have the most efficient manufacturing equipment has increased. This is the reason for the development of 3D printers using FDM technology for plastic parts. The software used by these 3D printers used in FDM technology is very sophisticated, as they allow the manufacture of very precise 3D prototypes, identical to the designed 3D model, through modern additive manufacturing techniques. The quality and mechanical strength of the prototypes obtained using 3D printers is very good. The materials used by the 3D printers manufactured by FDM are cheap and accessible. These 3D printers are used to make three-dimensional objects (gears, flanges, bearings, covers, casings, mechanisms, figurines, interior and exterior design elements, architectural models, medical models).
文摘利用不同厚度的亚波长介质块实现0~2π的相位变化,并基于惠更斯人工电磁表面原理设计了工作于28 GHz通信频段的全介质电磁透镜,该电磁透镜的焦距与口径比（F/D）为0.15。通过3D打印制备该电磁透镜,并将其与基片集成波导（SIW）贴片天线进行集成,构造了超低剖面的宽带透镜天线。全波分析与实验测量结果显示该电磁透镜能够将原SIW贴片天线的增益提高7 d B左右,而将3 d B波束宽度减小到10°左右,同时该透镜天线系统还具有良好的低副瓣。
文摘Printing short fibre/thermoplastic composites using the fused filament fabrication method sometimes creates a gap between print paths. In this study, the two-dimensional moving particle semi-implicit method for liquid simulation was applied to simulate the print-path fusion process. The three-dimensional movement of the nozzle was simulated using the sliding motion of the nozzle. The method was applied to the printing of short carbon fibre/polyamide-6 composites, and the simulation results were compared with those of experiments. The simulated results of the cross-sectional configuration agreed well with the experimental results. This will enable the optimization of printing process parameters thus reducing the gap between print paths.
