New methods for projecting a 3D object onto a free-form surface

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Jingyu Pei ◽  
Xiaoping Wang ◽  
Leen Zhang ◽  
Yu Zhou ◽  
Jinyuan Qian
Keyword(s):  
Approximate Solution ◽  
New Method ◽  
Free Form ◽  
Parallel Projection ◽  
Content Type ◽  
3D Object ◽  
New Methods ◽  
Free Form Surface ◽  
Newton Raphson ◽  
Raphson Iteration

Purpose This paper aims to provide a series of new methods for projecting a three-dimensional (3D) object onto a free-form surface. The projection algorithms presented can be divided into three types, namely, orthogonal, perspective and parallel projection. Design/methodology/approach For parametric surfaces, the computing strategy of the algorithm is to obtain an approximate solution by using a geometric algorithm, then improve the accuracy of the approximate solution using the Newton–Raphson iteration. For perspective projection and parallel projection on an implicit surface, the strategy replaces Newton–Raphson iteration by multi-segment tracing. The implementation takes two mesh objects as an example of calculating an image projected onto parametric and implicit surfaces. Moreover, a comparison is made for orthogonal projections with Hu’s and Liu’s methods. Findings The results show that the new method can solve the 3D objects projection problem in an effective manner. For orthogonal projection, the time taken by the new method is substantially less than that required for Hu’s method. The new method is also more accurate and faster than Liu’s approach, particularly when the 3D object has a large number of points. Originality/value The algorithms presented in this paper can be applied in many industrial applications such as computer aided design, computer graphics and computer vision.

The Study on the Linking-Up of Free-Form Surface Fiber Placement Track Based on Mesh Creating

2008 ◽  
Vol 392-394 ◽  
pp. 682-687 ◽  
Author(s):  
Zhong Xi Shao ◽  
Hong Ya Fu ◽  
De Cai Li
Keyword(s):  
Projective Plane ◽  
Calculation Method ◽  
New Method ◽  
Free Form ◽  
Parallel Projection ◽  
Reference Vector ◽  
Fiber Placement ◽  
Vertex Point ◽  
Free Form Surface ◽  
Pass Through

When using meshing creating method of FP (fiber placement) track, once the track point falls at some vertex point of mesh element, in the meantime the vertex point happens to be shared by several mesh elements, there needs a reasonable calculation method to select next mesh element which the FP track will pass through. Then it comes to the problem on linking of FP tracks. In order to solve it, in this paper, the author puts forward a new method, in which parallel projection theory is used, project need analytical mesh element and FP reference vector to a sound projective plane, on which the mesh element be selected and the FP track be calculated, then the FP track would be projected back to the placement surface. Program using this method realized a reasonable joint at the shared vertex point of meshing elements, which the FP direction has little change, and the mutation of track doesn’t come forth. So, the correctness of the method, which putted forward in this paper, is proved.

A new two-step adaptive direct slicing approach for bio-scaffolds in tissue engineering

2017 ◽  
Vol 23 (6) ◽  
pp. 1170-1184 ◽  
Author(s):  
Wangyu Liu ◽  
Mingke Li
Keyword(s):  
Tissue Engineering ◽  
Free Form ◽  
Exterior Surface ◽  
Content Type ◽  
Direct Slicing ◽  
Pore Architecture ◽  
Free Form Surface ◽  
Adaptive Direct Slicing ◽  
Internal Pore ◽  
Internal Architecture

Purpose This paper aims to propose the new two-step adaptive direct slicing method for building bio-scaffold with digital micro-mirror device (DMD)-based MPμSLA systems. Design/methodology/approach In this paper, the authors proposed a new approach to directly slice a scaffold’s CAD model (i.e the three-dimensional model built by computer-aided design platforms) and save the slices’ data as BMP (bitmap, i.e. the data format used in DMD) files instead of other types of two-dimensional patterns as an intermediary. The proposed two-step strategy in this paper, i.e. a CAD model’s exterior surface and internal architecture were sliced, respectively, at first, and then assembled together to obtain one intact slice. The assembly process is much easier and convenient based on the slice data in BMP format. To achieve the adaptive slicing for both the exterior part and internal part, two new indices, the exterior surface-dominated index and internal architecture-dominated index, are, respectively, utilized as the error estimation indices. The proposed approach in this paper is developed on SolidWorks platform, but it can also be implemented on other platforms. Findings The authors found that the approach is not only more accurate but also more efficient by avoiding the repeated running of those inefficient rasterization programs. The approach is able to save computer resource and time, and enhance the robustness of slicing program, as well as is appropriate for the scaffolds’ model with internal pore architecture and external free-form surface. Practical implications Bio-scaffolds in tissue engineering require precise control over material distribution, such as the porosity, connectivity, internal pore architecture and external free-form surface. The proposed two-step adaptive direct slicing approach is a good balance of slicing efficiency and accuracy and can be useful for slicing bio-scaffolds’ models. Originality/value This paper gives supports to build bio-scaffold with DMD-based MPμSLA systems.

The New Method of Free Form Surface Honing

CIRP Annals ◽  
1993 ◽  
Vol 42 (1) ◽  
pp. 425-428 ◽  
Author(s):  
Bogdan Nowicki ◽  
Maciej Szafarczyk
Keyword(s):  
New Method ◽  
Free Form ◽  
Free Form Surface

Analytical Boundary Method for Obtaining Feed Scallop of Toroidal Cutter in Multi-Axis Milling

2017 ◽  
Vol 728 ◽  
pp. 48-53 ◽  
Author(s):  
Hendriko Hendriko
Keyword(s):  
Inclination Angle ◽  
New Method ◽  
Free Form ◽  
Scallop Height ◽  
Surface Machining ◽  
Boundary Method ◽  
Surface Profiles ◽  
Free Form Surface ◽  
Toroidal Cutter

This paper presents a new method to calculate the feed scallop height for a toroidal cutter during a free-form surface machining in multi-axis milling. The proposed method is an extended analytical boundary method to define the cut geometry during a free-form surface milling. The algorithm was developed by taken into account the existence of inclination angle. The proposed method was successfully implemented to calculate the scallop for two model parts with different surface profiles. The accuracy was verified by comparing the scallop height calculated using the proposed method with those measured using Siemens-NX. The results proved that the proposed method was accurate

scholarly journals Selection of the Best Model of Distribution of Measurement Points in Contact Coordinate Measurements of Free-Form Surfaces of Products

Sensors ◽  
2019 ◽  
Vol 19 (24) ◽  
pp. 5346 ◽  
Author(s):  
Marek Magdziak
Keyword(s):  
Coordinate Measuring Machine ◽  
New Method ◽  
Free Form ◽  
Experimental Investigations ◽  
Accuracy Of Measurements ◽  
Measuring Machine ◽  
Coordinate Measurements ◽  
Free Form Surface ◽  
Free Form Surfaces ◽  
Selection Of

The article presents a new method for determining the distribution of measurement points, which can be used in the case of contact coordinate measurements of curvilinear surfaces of products. The developed method is based on multi-criteria decision analysis. In the case of the new method, the selection of the distribution of measurement points on free-form surfaces is carried out based on the analysis of five different criteria. The selection of the best model of the distribution of measurement points results from the accuracy of coordinate measurements, the time needed to complete measurement tasks, the number of measurement points, the accuracy of the substitute surface representing the measured free-form surface and the area where measurement points are located. The purpose of using the developed method of the distribution of measurement points is to increase the performance of coordinate measurements primarily by increasing the automation of strategy planning of measurements of curvilinear surfaces and improving the accuracy of measurements of free-form surfaces of products. The new method takes into account various aspects of coordinate measurements to determine the final model of the distribution of measurement points on measured surfaces of products, thereby increasing the probability of the proper determination (i.e., identifying the highest deviations of a product) of the location of measurement points on the surfaces of a measured object. The paper presents an example of the application of the created method, which concerns the selection of the best model of the distribution of measurement points on a selected free-form surface. This example is based on, among others, the results of experimental investigations, which were carried out by using the ACCURA II coordinate measuring machine equipped with the VAST XXT measuring probe and the Calypso measurement software. The results of investigations indicate a significant reduction in time of coordinate measurements of products when using the new method for determining the distribution of measurement points. However, shortening the time of coordinate measurements does not reduce their accuracy.

A New Method for Free Surface Polishing Based on Soft-Consolidation Abrasive Pneumatic Wheel

2012 ◽  
Vol 497 ◽  
pp. 190-194
Author(s):  
Shi Ming Ji ◽  
Xi Zeng ◽  
Ming Sheng Jing
Keyword(s):  
High Hardness ◽  
Polymer Binder ◽  
New Method ◽  
Rubber Matrix ◽  
Free Form ◽  
Silicone Sealant ◽  
Mechanics Model ◽  
Surface Polishing ◽  
Pneumatic Wheel ◽  
Free Form Surface

in order to improve the polishing efficiency to high hardness and high resistance free-form surface of mold, the paper present a new method based on soft-consolidation abrasive pneumatic wheel. The abrasive group is bond to the rubber matrix by the polymer binder. In this way, a flexible pneumatic wheel is formed to get copying contact with the free-form surface for efficient cutting. Combined with the elastic system theory, mechanics model of polishing is found. Scidic silicone sealant is used as the polymer binder, because of its excellent effect of adhesion. The result of experiment shows its wild prospects in the process of polishing.

Connection of electronic and microelectronic modules

2014 ◽  
Vol 31 (2) ◽  
pp. 86-89 ◽  
Author(s):  
Josef Sandera
Keyword(s):  
Design Methodology ◽  
Metal Electrode ◽  
New Method ◽  
Thermomechanical Loading ◽  
Content Type ◽  
Practical Solution ◽  
New Methods ◽  
Original Construction ◽  
Practical Implications ◽  
New System

Purpose – The purpose of this article is to describe the design of electronic and microelectronic modules and, in particular, it focuses on connecting system of electrical modules to the main board of printed board. The theory of thermomechanical loading of system is presented. New methods of rigid solder connection for electronic modules are also presented. Design/methodology/approach – A newly developed system with chip or cylindrical components is presented. The article describes a practical solution of connection with 0.603 and mini-metal electrode leadless face (MELF) surface mount device (SMD) resistors. Findings – A new method of rigid solder connection for electronic modules is presented. This system is original and patented. Practical implications – This solution is not used yet. Testing of a new system is executed now. Originality/value – This article shows a real and original construction with chip and cylindrical chip components.

Lubricant compatibility of FKM seals in synthetic oils

2019 ◽  
Vol 72 (5) ◽  
pp. 557-565
Author(s):  
Dilek Bulut ◽  
Tatjana Krups ◽  
Gerhard Poll ◽  
Ulrich Giese
Keyword(s):  
Polyethylene Glycol ◽  
Design Methodology ◽  
Elevated Temperatures ◽  
Failure Mechanisms ◽  
Standard Test ◽  
New Method ◽  
Static Tests ◽  
Content Type ◽  
Lip Seals ◽  
First Results

Purpose Elastomer seals are used in many applications. They are exposed to lubricants and additives at elevated temperatures, as well as mechanical stresses. They can only provide good sealing function when they have resistance to those factors. There are many elastomer-lubricant compatibility tests based on DIN ISO 1817 in industry. However, they are insufficient and costly. Correlations between the tests and the applications are inadequate. The purpose of this study is investigating lubricant compatibility of fluoroelastomers (FKM) seals in polyethylene-glycol (PG)- and polyalphaolefin (PAO)- based synthetic oils and developing a methodology to predict seal service life. Design/methodology/approach A new compatibility test which is more sufficient in terms of time and cost was developed and compared with a standard test, currently used in industry. Compatibility of FKM radial lip seals with PG- and PAO-based synthetic oils with different additives was investigated chemically and dynamically. Failure mechanisms were examined. Findings The new method and the Freudenberg Flender Test FB 73 11 008 showed similar results concerning damages and similar tendencies regarding wear. The additive imidazole derivative was the most critical. Static tests give indications of possible chemically active additives, but alone they are insufficient to simulate the dynamic applications. Originality/value The paper describes a new method to investigate elastomer-lubricant compatibility and gives first results with a variety of lubricants.

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