Adaptive Slicing Algorithm Research Articles

Development of an Adaptive Slicing Algorithm of Laminated Object Manufacturing Based 3D Printing for Freeform Formwork

Recently, as “Freeform buildings” have increased in number, studies on ways to increase productivity in the construction of freeform buildings are increasing. In the case of 3D printing in construction, many studies are being conducted using the material extrusion method; among the 3D printing methods, manufacturing freeform forms using laminated object manufacturing (LOM) can overcome the limitation presented above. However, there is a lack of cases used in LOM construction sites, so it is necessary to increase the productivity of construction work and study the slicing method suitable for construction. Therefore, in this paper, we propose using study criteria and adaptive slicing methods to combine both the shape error and the manufacturing time of freeform construction. A case study was conducted to verify the results of this study; the freeform concrete form manufacturing with the algorithm that proposed this study could save 66.1% of the manufacturing time compared with CNC milling, and it needs 19.8% less manufacturing time than the existing uniform slicing method. This is a result of the production of one freeform form, and it can be expected to have a greater effect if applied to many freeform forms used in construction sites. In addition, the results of this study can be used as a decision-making tool that can determine the shape and manufacturing time of production according to the on-site situation.

A Legorization method based on 3D color printing trajectory

In this paper, a Legorization method which can reconstruct LEGO model with complex internal and external structures from 3D color printing trajectory is proposed. Different from voxelization methods, by combining advanced adaptive slicing algorithm with building “high-resolution” regions with thin plates, the reconstruction accuracy of initial LEGO units can be guaranteed. Furthermore, the tree structure is employed for automatically generating support structures which can be converted into LEGO support structures. By adopting split assembly appropriately and implementing combination of these parts accurately, the reducing supporting structures can be further simplified. In order to optimize the Legorization scheme, a machine learning method is used to guarantee the quality and efficiency of the reconstruction work. Complex LEGO models are provided to demonstrate the effectiveness of the proposed method.

A novel adaptive slicing algorithm based on ameliorative area ratio and accurate cusp height for 3D printing

PurposeAdaptive slicing is a key step in three-dimensional (3D) printing as it is closely related to the building time and the surface quality. This study aims to develop a novel adaptive slicing method based on ameliorative area ratio and accurate cusp height for 3D printing using stereolithography (STL) models.Design/methodology/approachThe proposed method consists of two stages. In the first stage, the STL model is sliced with constant layer thickness, where an improved algorithm for generating active triangular patches, the list is developed to preprocess the model faster. In the second stage, the model is first divided into several blocks according to the number of contours, then an axis-aligned bounding box-based contour matching algorithm and a polygons intersection algorithm are given to compare the geometric information between several successive layers, which will determine whether these layers can be merged to one.FindingsSeveral benchmarks are applied to verify this new method. Developed method has also been compared with the uniform slicing method and two existing adaptive slicing methods to demonstrate its effectiveness in slicing.Originality/valueCompared with other methods, the method leads to fewer layers whilst keeping the geometric error within a given threshold. It demonstrates that the proposed slicing method can reach a trade-off between the building time and the surface quality.

A New Adaptive Slicing Algorithm Based on Slice Contour Reconstruction in Layered Manufacturing Process

Computer-Aided Design and Applications is an international journal on the applications of CAD and CAM. It publishes papers in the general domain of CAD plus in emerging fields like bio-CAD, nano-CAD, soft-CAD, garment-CAD, PLM, PDM, CAD data mining, CAD and the internet, CAD education, genetic algorithms and CAD engines. The journal is aimed at all developers and users of CAD technology to ptovide CAD solutions for various stages of design and manufacturing. The journal publishes all about Computer-Aided Design and Computer-Aided technologies.

Intelligent Process Planning for Additive Manufacturing

Abstract This paper introduces an intelligent approach for process planning of additive manufacturing (AM) in digital environment. A global adaptive slicing algorithm is developed and embedded in the introduced concept, which determines the layer thicknesses and widths based on the minimization of the deviations between the CAD model boundary and its stepped approximation. It is discussed that there are different metrics to measure the deviations such as cusp height, cusp volume and surface roughness criteria. A new criterion is developed to globally minimize the overall volumetric deviations of the final product from the desired geometric model. The proposed methodology uses the locally optimized layer thicknesses as the inputs to calculate the globally optimized layer thicknesses and the optimal contour for each layer. The global optimization problem is highly nonlinear that can be solved with a metaheuristic algorithm such as Simulated Annealing.

Surface roughness improvement using volumetric error control through adaptive slicing

This research presents the development of advanced adaptive slicing procedure to improve the surface roughness by adaptively selecting the layer thickness based on the user specified volumetric error (VE) value bound. However, most of the researchers have developed slicing procedures to improve the part surface quality under cusp height concept. Moreover, cusp height-based adaptive slicing procedures do not have any direct control on VE. It is possible that with very little variation in cusp height the large variation in VE may occur on shallow surfaces. In contrast, the advanced adaptive slicing algorithm has been developed and implemented to vary layer thickness directly under a specified VE value on the fused deposition modelling (FDM) part surfaces although this procedure can also be useful for all AM processes to control VE. In this work, different models have been used to estimate VE and surface roughness according to the layer thickness changes.

Adaptive slicing algorithm to keep model characteristics for rapid prototyping

Adaptive slicing algorithm to keep model characteristics for rapid prototyping

Global adaptive slicing of NURBS based sculptured surface for minimum texture error in rapid prototyping

Purpose – This paper aims to propose a global adaptive direct slicing technique of Non-Uniform Rational B-Spline (NURBS)-based sculptured surface for rapid prototyping where the NURBS representation is directly extracted from the computer-aided design (CAD) model. The imported NURBS surface is directly sliced to avoid inaccuracies due to tessellation methods used in common practice. The major objective is to globally optimize texture error function based on the available range of layer thicknesses of the utilized rapid prototyping machine. The total texture error is computed with the defined error function to verify slicing efficiency of this global adaptive slicing algorithm and to find the optimum number of slices. A variety of experiments are conducted to study the accuracy of the developed procedure, and the results are compared with previously developed algorithms. Design/methodology/approach – This paper proposes a new adaptive algorithm which globally optimizes a texture error function produced by staircase effect for a user-defined number of layers. The adaptive slicing algorithm dynamically calculates optimized slicing thicknesses based on the rapid prototyping machine’s specifications to minimize the texture error function. This paper also compares the results of implementing the developed methodology with the results of previously developed algorithms and presents cost-effective optimum slicing layer thicknesses. Findings – A new methodology for global adaptive direct slicing algorithm of CAD models, based on a texture error function for the final product and the possible layer thicknesses in rapid prototyping, has been developed and implemented. Comparing the results of implementation with the common practice for several case studies shows that the proposed approach has greater slicing efficiency. Typically, by utilizing this approach, the number of prototyping layers can be reduced by 20-50 per cent compared to the slicing with other algorithms, while maintaining or improving the accuracy of the final manufactured surfaces. Therefore, the developed slicing method provides a better solution to trade-off between the rapid prototyping time and the rapid prototyping accuracy. For the many advantages of global direct slicing, it can be seen as the future solution to the slicing process in rapid prototyping systems. Originality/value – This paper presents an innovative approach in direct global adaptive slicing of the additive manufacturing parts. The novel definition of an error function which comprehensively addresses the resulting manufactured surface quality of the entire product allows presenting an objective function to solve and to find the optimum selection of all the layer thicknesses during the slicing process.

Close to CAD model curved-form adaptive slicing

Purpose – The main aim of this study is to generate curved-form cut on the edge of an adaptive layer. The resulting surface would have much less geometry deviation error and closely fit its computer aided design (CAD) model boundary. Design/methodology/approach – This method is inspired by the manual peeling of an apple in which a knife's orientation and movement are continuously changed and adjusted to cut each slice with minimum waste. In this method, topology and geometry information are extracted from the previously generated adaptive layers. Then, the thickness of an adaptive layer and the bottom and top contours of the adjacent layers are fed into the proposed algorithm in the form of the contour and normal vector to create curved-form sloping surfaces. Following curved-form adaptive slicing, a customized machine path compatible with a five-axis abrasive waterjet (AWJ) machine will be generated for any user-defined sheet thicknesses. Findings – The implemented system yields curved-form adaptive slices for a variety of models with diverse types of surfaces (e.g. flat, convex, and concave), different slicing direction, and different number of sheets with different thicknesses. The decrease in layer thickness and increase of the number of the sloped cuts can make the prototype as close as needed to the CAD model. Research limitations/implications – The algorithm is designed for use with five-axis AWJ cutting of any kind of geometrical complex surfaces. Future research would deal with the nesting problem of the layers being spread on the predefined sheet as the input to the five-axis AWJ cutter machine to minimize the cutting waste. Practical implications – The algorithm generates adaptive layers with concave or convex curved-form surfaces that conform closely to the surface of original CAD model. This will pave the way for the accurate fabrication of metallic functional parts and tooling that are made by the attachment of one layer to another. Validation of the output has been tested only as the simulation model. The next step is the customization of the output for the physical tests on a variety of five-axis machines. Originality/value – This paper proposes a new close to CAD design sloped-edge adaptive slicing algorithm applicable to a variety of five-axis processes that allow variable thickness layering and slicing in different orientations (e.g. AWJ, laser, or plasma cutting). Slices can later be bonded to build fully solid prototypes.

Adaptive Slicing Algorithm Based on STL Model

An adaptive slicing algorithm based on stereo lithography (STL) model was proposed in order to improve the forming precision of product in rapid prototyping. In the algorithm, the topological information of STL model was established, and the relationship between triangle facet and vertexes was constructed. And the adaptive slicing process based on STL model was implemented using the proposed method with combination of intersection points tracking and marking. The slicing thickness was automatically calculated according to the area differential ratio of adjacent slices.

3D sculpture algorithm based on hierarchical slicing theory

Some kinds of fast slicing algorithms based on the STL models were analyzed in this paper.Firstly,sorting the apex of the triangular facets according to ascending order in their slice direction was proposed to filter out redundant vertex quickly;secondly,the triangle-vertex list and facet vector were established to reconstruct the topology information of the STL model;finally,the efficient adaptive slicing algorithm was realized with geometric continuity algorithm,and through C+ + programming,this algorithm was realized.The experimental results show that the technique is feasible that the layered manufacturing in rapid prototyping technology can be applied to three-dimensional carving CAD/CAM.

An Adaptive Slicing Algorithm and Its Application in 3D Finite Difference Mesh Generation

An Adaptive Slicing Algorithm and Its Application in 3D Finite Difference Mesh Generation

New concept contemporary integrated rapid prototyping system and its software implementation

In this paper, a new concept Contemporary Integrated Rapid Prototyping System (CIRPS) is proposed and the software system is developed under the environment of Mechanical Desktop (MDT). First of all, the systematic framework of the software is described. Then the methods to internally represent 3D model built in MDT and to extract the model data including geometrical and topological information are studied. Based on them, an adaptive direct slicing algorithm is constructed and realised by applying a grid-based intersection principle between the plane and parametric surface. In addition, a novel 2D layer file named CLA is proposed. Finally, all functional modules are developed employing VC++ and MDT API, thus implementing the seamless integration of 3D modelling, model data processing and NC codes generation. The work of this study is significant in improving the part quality, simplifying the RP data preprocessing and calling for the market reorientation of RP devices.

Implementation of a New Adaptive Slicing Algorithm for the Rapid Prototyping Manufacturing System

Rapid prototyping is an automated manufacturing process that quickly builds physical models from three-dimensional (3-D) prototype computer-aided design files. It dramatically speeds up design and manufacturing processes and substantially reduces the cost. This paper presents a new adaptive slicing algorithm for rapid prototyping (RP) processes. The proposed adaptive slicing approach determines the layer thickness based on comparing the contour circumference or the center of gravity of the contour with those of the adjacent layer. Most commercial rapid prototyping systems use uniform slicing procedures with a fixed layer thickness to build parts. To implement the adaptive slicing algorithm, we developed a thermal extrusion based RP mechatronics system equipped with a linear planar servo motor. The RP material is wax. The XYZ table is controlled using a PC based multi-axis DSP motion controller. The RP material flow rate for the thermal extrusion head is controlled using a dc servo motor and motion controller. The Taguchi method was used to analyze the process parameters for the proposed RP system to improve the quality of the RP part. Based on the experimental results, the proposed RP mechatronics system can produce good quality RP parts with the adaptive slicing algorithm. The proposed RP system also implements the high-precision exterior, high-speed interior slicing strategy for STL models.

The Development of an Intelligent Web-Based Rapid Prototyping Manufacturing System

A rapid prototyping (RP) machine system which combines a PC-based controller with the thermal-extrusion method is presented. The proposed RP system offers a three-axis platform, an extrusion head, a temperature controller, and a PC-based control system. Low-cost acrylonitrile-butadiene-styrene (ABS) pellets/powder are used for thermal extrusion, although the system is easily adapted to other not-too-dissimilar materials. In order to improve the quality of RP part, the Taguchi method was used to analyzing the process parameters of the proposed RP system. Based on the experimental results, the proposed RP mechatronics system can produce good quality RP parts. The RP software technique includes slicing, support, tool path, and motion code generation. This paper also presents a new adaptive slicing algorithm for RP system. According to this algorithm, the three-dimensional (3-D) computer-aided design (CAD) model can be sliced with different thickness automatically by comparing the contour circumference or the center of gravity of the contour with those of the adjacent layer. With this adaptive slicing method, the part can be fabricated faster than it uses uniform slicing method with identical accuracy. Finally, the intelligent web-based RP system allows remote users to upload an STL file, to directly building up of the physical model, and to monitor the actual fabrication process from a charged coupled devices (CCD) camera located in the RP machine itself. The user does not need to buy an expensive RP machine; instead, he can rent time and uses the machine remotely via the Internet.<br><br>Note to Practitioners-RP has being used as an essential augmented tool between CAD and computer-aided manufacturing (CAM) for product manufacturing. RP uses layered manufacturing technology to produce complicated prototypes directly from a CAD model. As imaging, materials, and processing techniques improve, RP functions such as assembly fit, tooling masters, prototype tools, and prototype parts are made possible. RP technology that can construct parts of multiple materials, colors, and even parts composed of composite materials will soon be available. In this paper, an RP machine system which combines PC-based controller with thermal extrusion method is presented. Low-cost ABS pellets are used for thermal extrusion, although the system is easily adapted to other not-too-dissimilar materials. Based on the experimental results, the proposed RP mechatronics system can produce good quality RP parts. In this paper, a new adaptive slicing algorithm is developed to decrease fabrication time without much reducing the model accuracy. According to this algorithm, the 3-D CAD model can be sliced with different thickness automatically. With this adaptive slicing method, the part can be fabricated much faster than it uses traditional uniform slicing method. Finally, the intelligent web-based RP system has been developed which allows remote users to upload a CAD file of the part, direct building up of the physical model, and monitoring of the actual fabrication process from a CCD camera located in the RP machine itself. The greatest advantage is that user does not need to buy an expensive RP machine; instead he rents time and uses the machine remotely via the Internet. This really drastically reduces the production development cycle for the highly competitive time-to-market challenge.

A process planning method for improving build performance in stereolithography

A process planning method is presented to aid stereolithography users in selecting appropriate values of process variables in order to achieve characteristics desired in a part to be fabricated. To accomplish this, the method achieves a balance of objectives specified by geometric tolerances, surface finishes, and part build time, where the balance is specified through preferences on the objectives. Given these objectives and preferences, values are chosen for six process variables to best achieve the balance of objectives. The process variables include part orientation, layer thicknesses, and four recoat variables (Z-level wait time, sweep period, hatch overcure, and fill overcure). The process planning method is adapted from multiobjective optimization and utilizes empirical data, analytical models, and heuristics to quantitatively relate process variables to the objectives. Of particular importance, a new adaptive slicing algorithm has been developed. The process planning method is demonstrated on a part with non-trivial geometric features.

Generating Optimal Slice Data for Layered Manufacturing

Staircase errors are inherent in layered manufacturing because the fabrication processes involve layering of materials. The CAD input format that reduces this error has, therefore, been investigated by several researchers. Among others, adaptive slicing methods improve the accuracy and the build speed of a model using variable slice thicknesses. However, these methods have problems in practice owing to computational inefficiency. A new adaptive slicing algorithm that gives a drastic improvement in computing time is proposed in this research. It uses contour line intervals between two consecutive slices instead of calculating the slice thickness at each sampled point. The calculation efficiency is further improved by introducing the vertical character lines of the model. The results in terms of accuracy and speed are compared with the existing methods.