Interference Detection of Non-Convex Solids for Manipulators

1994 ◽  
Author(s):  
Karim A. Abdel-Malek ◽  
Burton Paul
Keyword(s):  
Computer Aided Design ◽  
Analytical Study ◽  
Moving Objects ◽  
Computational Method ◽  
Interference Detection ◽  
Curved Surfaces ◽  
Multiply Connected ◽  
Points Of Interest ◽  
Intersection Points ◽  
Aided Design

Abstract When performing a computer simulation on analytical study of robot motions it is possible to unwittingly require a part of the robot (e.g. the hand) to interpenetrate (i.e. to interfere with) another part (e.g. an arm). It is therefore important to be able to predict in advance whether self interference or collision of any type occurs. This problem arises in fields of interest other than robotics, e.g. computer aided design and computer graphics. In this report, we have developed a computational method which predicts interference of moving objects in space. The method works for non-convex solids and multiply-connected solids (solids containing holes). The method checks the boundaries of surfaces enveloping solids for interference. Every pair of surfaces (one on each body) are examined for points of intersection. Points of interest are then studied to determine whether any two solids do interfere. The theory is developed for planar, ruled, and double curved surfaces.

scholarly journals Computer-Aided Sketching: Incorporating the Locus to Improve the Three-Dimensional Geometric Design

Symmetry ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1181 ◽  
Author(s):  
José Ignacio Rojas-Sola ◽  
David Hernández-Díaz ◽  
Ricardo Villar-Ribera ◽  
Vicente Hernández-Abad ◽  
Francisco Hernández-Abad
Keyword(s):  
Computational Geometry ◽  
Computer Aided Design ◽  
Three Dimensional ◽  
Geometric Design ◽  
Curved Surfaces ◽  
Two Dimensional ◽  
Technical Design ◽  
Computer Aided ◽  
Aided Design

This article presents evidence of the convenience of implementing the geometric places of the plane into commercial computer-aided design (CAD) software as auxiliary tools in the computer-aided sketching process. Additionally, the research considers the possibility of adding several intuitive spatial geometric places to improve the efficiency of the three-dimensional geometric design. For demonstrative purposes, four examples are presented. A two-dimensional figure positioned on the flat face of an object shows the significant improvement over tools currently available in commercial CAD software, both vector and parametric: it is more intuitive and does not require the designer to execute as many operations. Two more complex three-dimensional examples are presented to show how the use of spatial geometric places, implemented as CAD software functions, would be an effective and highly intuitive tool. Using these functions produces auxiliary curved surfaces with points whose notable features are a significant innovation. A final example provided solves a geometric place problem using own software designed for this purpose. The proposal to incorporate geometric places into CAD software would lead to a significant improvement in the field of computational geometry. Consequently, the incorporation of geometric places into CAD software could increase technical-design productivity by eliminating some intermediate operations, such as symmetry, among others, and improving the geometry training of less skilled users.

scholarly journals Computational wrapping: A universal method to wrap 3D-curved surfaces with nonstretchable materials for conformal devices

2020 ◽  
Vol 6 (15) ◽  
pp. eaax6212 ◽  
Author(s):  
Yu-Ki Lee ◽  
Zhonghua Xi ◽  
Young-Joo Lee ◽  
Yun-Hyeong Kim ◽  
Yue Hao ◽  
...  
Keyword(s):  
Computer Aided Design ◽  
Reliable Method ◽  
Design Method ◽  
Universal Method ◽  
Curved Surfaces ◽  
Two Dimensional ◽  
Steel Sheets ◽  
Computer Aided ◽  
Conformal Structures ◽  
Aided Design

This study starts from the counterintuitive question of how we can render conventional stiff, nonstretchable, and even brittle materials sufficiently conformable to fully wrap curved surfaces, such as spheres, without failure. Here, we extend the geometrical design method of computational origami to wrapping. Our computational wrapping approach provides a robust and reliable method for fabricating conformal devices for arbitrary curved surfaces with a computationally designed nonpolyhedral developable net. This computer-aided design transforms two-dimensional (2D)–based materials, such as Si wafers and steel sheets, into various targeted conformal structures that can fully wrap desired 3D structures without fracture or severe plastic deformation. We further demonstrate that our computational wrapping approach enables a design platform that can transform conventional nonstretchable 2D-based devices, such as electroluminescent lighting and flexible batteries, into conformal 3D curved devices.

Microstructure Feature Recognition for Materials Using Surfacelet-Based Methods for Computer-Aided Design-Material Integration

2014 ◽  
Vol 136 (6) ◽  
Author(s):  
Namin Jeong ◽  
David W. Rosen
Keyword(s):  
Computer Aided Design ◽  
Feature Recognition ◽  
Computational Method ◽  
Geometric Features ◽  
Material Microstructure ◽  
Control Material ◽  
Computer Aided ◽  
Aided Design ◽  
And Control ◽  
Material Information

With the material processing freedoms of additive manufacturing (AM), the ability to characterize and control material microstructures is essential if part designers are to properly design parts. To integrate material information into Computer-aided design (CAD) systems, geometric features of material microstructure must be recognized and represented, which is the focus of this paper. Linear microstructure features, such as fibers or grain boundaries, can be found computationally from microstructure images using surfacelet based methods, which include the Radon or Radon-like transform followed by a wavelet transform. By finding peaks in the transform results, linear features can be recognized and characterized by length, orientation, and position. The challenge is that often a feature will be imprecisely represented in the transformed parameter space. In this paper, we demonstrate surfacelet-based methods to recognize microstructure features in parts fabricated by AM. We will provide an explicit computational method to recognize and to quantify linear geometric features from an image.

Computer-Aided Design of Curved Surfaces With Automatic Model Generation

1982 ◽  
Vol 104 (4) ◽  
pp. 817-824 ◽  
Author(s):  
S. M. Staley ◽  
R. B. Jerard ◽  
P. R. White
Keyword(s):  
Computer System ◽  
Computer Aided Design ◽  
Three Dimensional ◽  
Model Generation ◽  
Curved Surfaces ◽  
B Spline ◽  
Three Dimensional Objects ◽  
Computer Aided ◽  
Automatic Model Generation ◽  
Aided Design

The design and visualization of three-dimensional objects with curved surfaces have always been difficult. This paper describes a computer system that facilitates both the design and visualization of such surfaces. The system enhances the design of these surfaces by virtue of various interactive techniques coupled with the application of B-Spline theory. Visualization is facilitated by including a specially built model-making machine that produces three-dimensional foam models. Thus the system permits the designer to define an object and, with little additional effort, produce an inexpensive model of the object which is suitable for evaluation and presentation.

Residual stress and quantitative phase mapping on complex geometries

2014 ◽  
Vol 29 (2) ◽  
pp. 176-185 ◽  
Author(s):  
Masoud Allahkarami ◽  
Jay C. Hanan
Keyword(s):  
Residual Stress ◽  
Computer Aided Design ◽  
Complex Geometry ◽  
Geometry Optimization ◽  
Curved Surfaces ◽  
Laser Alignment ◽  
Fine Mesh ◽  
Alignment System ◽  
Aided Design ◽  
Five Axis

As a consequence of substantial advances in computer-aided design and manufacturing technology, engineering parts are no longer restricted to combination of simple geometrical shapes. Implementing complex curved surfaces in engineering components in combination with finite-element geometry optimization has become a prevalent means of designing a part. Measuring residual stresses using X-ray diffraction (XRD) on complex curved surfaces requires further development of current measurement methods. Here we investigate how a laboratory XRD system equipped with a five-axis stage and two-dimensional detector can execute sin2ψ residual stress measurements on curved surfaces. Shadowing that blocks the diffracted beam to reach the detector was avoided using proper rotations and tilting of the sample. A standard video-laser alignment system commonly used to manually place the sample in the center of diffraction was used to also generate virtual maps of the sample's curved surfaces on a fine mesh grid. The geometry was then used for setting the required rotations and tilt angles. A set of diffraction frames collected using this method on a model zirconia dental ceramic, afforded the opportunity to superimpose phase and stresses on a complex geometry. This is a step forward for the XRD technology, and its usefulness applies to many different industries.

A Separating Channel Decomposition Algorithm for Nonconvex Polygons With Application in Interference Detection

1989 ◽  
Vol 111 (2) ◽  
pp. 270-277 ◽  
Author(s):  
T. S. Ku ◽  
B. Ravani
Keyword(s):  
Design Automation ◽  
Computer Aided Design ◽  
Companion Paper ◽  
Detection Algorithm ◽  
Geometric Constraints ◽  
Decomposition Algorithm ◽  
Interference Detection ◽  
Aided Design ◽  
Computational Basis ◽  
Channel Decomposition

An algorithm for efficient decomposition of interface channels between nonconvex polygons in a Computer-Aided Design (CAD) environment is presented. This algorithm forms the computational basis for the solution of several design automation problems. In this paper, the channel decomposition algorithm is presented and applied to the problem of interference detection between nonconvex polygons. The resulting interference detection algorithm does not require preprocessing of the data and uses a simple data structure. In a companion paper (Ku and Ravani, 1989), the rigid channel decomposition algorithm is applied to the problem of model-based rigid-body guidance in presence of geometric constraints.

Computer-Aided Design of Composite Materials Using Reversible Multiscale Homogenization and Graph-Based Software Engineering

2018 ◽  
Vol 779 ◽  
pp. 11-18 ◽  
Author(s):  
Alexander Pavlovich Sokolov ◽  
Anton Yurievich Pershin
Keyword(s):  
Composite Materials ◽  
Software Engineering ◽  
Computational Methods ◽  
Computer Aided Design ◽  
Homogenization Method ◽  
Computational Method ◽  
Mathematical Basis ◽  
Computer Aided ◽  
Aided Design ◽  
Multiscale Homogenization

In this work, a new software for computer-aided design of composite materials with predefined thermomechanical properties is presented in case of incomplete input data. The mathematical basis of underlying computational method of the properties identification is a modified method of multiscale homogenization named reversible multiscale homogenization method. The system has a modular architecture and includes software implementation of the reversible multiscale homogenization method based on a new technique of construction of software implementations of complex computational methods. The latter was named «Graph-based software engineering» (GBSE) and is based on category and graph theories. The corresponding numerical and experimental results were obtained and compared. The expediency of GBSE approach is discussed for the case of the development of complex computational methods required when solving the applied problems of the design of new heterogeneous materials.

Remove Mesh Self-Intersections Based on Light Projection Algorithm

2014 ◽  
Vol 598 ◽  
pp. 471-475
Author(s):  
Zhi Wei Huang ◽  
Ning Dai ◽  
Chang Ye Guo ◽  
Chang You Wu ◽  
Wei Yin ◽  
...  
Keyword(s):  
Computer Aided Design ◽  
Projection Algorithm ◽  
Radius Of Curvature ◽  
Triangle Mesh ◽  
Offset Distance ◽  
Design And Manufacturing ◽  
Cad Cam ◽  
Intersection Points ◽  
Aided Design ◽  
Geometric Operation

Offset in computer aided design and manufacturing (CAD/CAM) is a kind of important geometric operation, such as rapid prototyping technology, NC machining, the collision detection, etc. When offset distancedis greater than the minimum radius of curvature on the original surface, or part of the distance between parts of curved surface pieces, it causes self-intersection. Self-intersection makes distance between two models smaller than the offset distancer, leading to offset model local intersection or distortion. This paper proposes a method based on light projection algorithm to remove self-intersections and achieve good results. Firstly, set point coordinates on the original model as the light source locations and build the projection light according to adjacent plane vector weighted sum.Secondly, the projection light passes through the offset model. We extract the triangles on the outermost layer and load it into a list. Finally it is essential to filter the intersection points and construct triangle mesh. We use different discrete data models to do experiments and prove the validity and practicability of the algorithm.

Accurate Tool Path Generation Method for Large-Scale Discrete Shapes

2019 ◽  
Vol 13 (2) ◽  
pp. 279-288 ◽  
Author(s):  
Hiromu Kitahara ◽  
Jun’ichi Kaneko ◽  
Masahiro Ajisaka ◽  
Takeyuki Abe ◽  
Kenichiro Horio ◽  
...  
Keyword(s):  
Computer Aided Design ◽  
Large Scale ◽  
Tool Path ◽  
Curved Surfaces ◽  
Product Model ◽  
Tool Paths ◽  
Spherical Surfaces ◽  
Tool Axis ◽  
End Mills ◽  
Aided Design

Three-axis ball end mills are used for the finishing of metal molds of complicated curved surfaces. Typically, a tool path of this shape machining is derived from the geometric calculations of a tool used, and a product model that is a computer aided design (CAD)-based polyhedron approximating the shape. The polyhedron is more complicated to approximate a shape with more curved surfaces, as it is highly time consuming. To solve this problem, methods to accelerate geometric calculations using a computer graphics drawing processing mechanism were proposed. However, these methods cannot guard against errors arising from the approximation of an inverse offset shape using a set of polygons. In the present study, we propose a method to generate tool paths accurately based on calculating the crossing points of the tool axis and defining the offset surface as a set of polygons, cylindrical surfaces, and spherical surfaces. With this method, it is expected that the height of an area, which was divided by fine polygons in previous methods, can be derived accurately, and a tool path can be generated with high precision.

A Separating Channel Decomposition Algorithm for Non-Convex Polygons With Application in Interference Detection

1988 ◽  
Author(s):  
T. S. Ku ◽  
B. Ravani
Keyword(s):  
Computer Aided Design ◽  
Companion Paper ◽  
Detection Algorithm ◽  
Geometric Constraints ◽  
Decomposition Algorithm ◽  
Interference Detection ◽  
Convex Polygons ◽  
Aided Design ◽  
Computational Basis ◽  
Channel Decomposition

Abstract An algorithm for efficient decomposition of interface channels between non-convex polygons in a Computer-Aided Design (CAD) environment is presented. This algorithm forms the computational basis for the solution of several design automation problems. In this paper, the channel decomposition algorithm is presented and applied to the problem of interference detection between non-convex polygons. The resulting interference detection algorithm does not require preprocessing of the data and uses a simple data structure. In a companion paper (Ku and Ravani 1988), the channel decomposition algorithm is applied to the problem of model-based rigid-body guidance in presence of geometric constraints.

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