The Point Cloud Collection of the Incisor Teeth of Beaver and Re-Construction of its Curved Surface

2012 ◽  
Vol 426 ◽  
pp. 387-390
Author(s):  
Feng Xie ◽  
J. W. Zhao ◽  
F. Ju
Keyword(s):  
Mechanical Property ◽  
Point Cloud ◽  
State Of The Art ◽  
Cutting Tools ◽  
Three Dimensional ◽  
Evolutionary Process ◽  
Geometric Shape ◽  
Curved Surface ◽  
Surface Model ◽  
Dimensional Surface

The research of state-of-the-art bionics shows that teeth, claw and animal surface etc. of a lot of animals obtain perfect geometric shape and biologic-mechanical property after long evolutionary process. The paper was based on the bionic research of the incisor teeth of beaver. The point cloud of the incisor teeth was obtained by Reverse Engineering (RE) technology. And the curved surface of the incisor teeth was re-constructed by RE software to get its three-dimensional surface model. All of those research results will supply the base of bionic study to the optimization of the geometric shape and the mechanical property of cutting tools.

scholarly journals Automated 3D-Objectdocumentation on the Base of an Image Set

2011 ◽  
Vol 6 ◽  
pp. 370-375
Author(s):  
Sebastian Vetter ◽  
Gunnar Siedler
Keyword(s):  
Point Cloud ◽  
Search Algorithm ◽  
Three Dimensional ◽  
Point Clouds ◽  
Spatial Dimension ◽  
High Accuracy ◽  
Relative Orientation ◽  
Reference Points ◽  
Surface Model ◽  
Object Surface

Digital stereo-photogrammetry allows users an automatic evaluation of the spatial dimension and the surface texture of objects. The integration of image analysis techniques simplifies the automation of evaluation of large image sets and offers a high accuracy [1]. Due to the substantial similarities of stereoscopic image pairs, correlation techniques provide measurements of subpixel precision for corresponding image points. With the help of an automated point search algorithm in image sets identical points are used to associate pairs of images to stereo models and group them. The found identical points in all images are basis for calculation of the relative orientation of each stereo model as well as defining the relation of neighboured stereo models. By using proper filter strategies incorrect points are removed and the relative orientation of the stereo model can be made automatically. With the help of 3D-reference points or distances at the object or a defined distance of camera basis the stereo model is orientated absolute. An adapted expansion- and matching algorithm offers the possibility to scan the object surface automatically. The result is a three dimensional point cloud; the scan resolution depends on image quality. With the integration of the iterative closest point- algorithm (ICP) these partial point clouds are fitted to a total point cloud. In this way, 3D-reference points are not necessary. With the help of the implemented triangulation algorithm a digital surface models (DSM) can be created. The texturing can be made automatically by the usage of the images that were used for scanning the object surface. It is possible to texture the surface model directly or to generate orthophotos automatically. By using of calibrated digital SLR cameras with full frame sensor a high accuracy can be reached. A big advantage is the possibility to control the accuracy and quality of the 3d-objectdocumentation with the resolution of the images. The procedure described here is implemented in software Metigo 3D.

Proportional Integral Control Approach for Controlling the Temperatures of Multi-Steel Cylinders Barrel in an Injection Molding Machine

2015 ◽  
Author(s):  
Ma’moun Abu-Ayyad ◽  
Tapan Khilnani
Keyword(s):  
Injection Molding ◽  
Three Dimensional ◽  
Surface Model ◽  
Process Variables ◽  
Molding Machine ◽  
Injection Molding Machine ◽  
Proportional Integral ◽  
Non Linear ◽  
Sampling Instant ◽  
Dimensional Surface

This work presents a three dimensional prototype of the surface model to demonstrate the working of the controller. The three dimensional surface model is a prototype of the Injection Molding Machine (IMM), wherein the temperature of the system needs to be gradually increased to a very high temperature to melt plastics uniformly, despite the non-linear process. This process tends to be non-linear mainly due to thermal loss, heat transfer between the three cylinders and atmospheric disturbances. This paper presents a unique approach for designing a nonlinear surface model-based for controlling the temperature of multi steel cylinders in an injection molding machine. The innovation of this strategy is that the controller structure uses the nonlinear model to update the process variables at every sampling instant while the closed-loop control is executed. In this work, a new optimization routine will be used to minimize the errors between the model and process outputs. This allows the determination of the system’s variables resulting in a new set of the Proportional Integral (PI) controller parameters with every sampling instant. The most important feature of 3-dimensional surface model control strategy is that it uses the process’ variables to construct the surface model which are used in calculation of the control actions. In the meantime, this surface model is constructed offline by conducting several open-loop tests using different input signals and profiles while the measured output of the process is recorded. From these data, the main dynamic parameters of the process (process gain and time constant) are extracted to construct the surface model. Finally, the control law of the PI approach is updated every sampling instant to counteract the nonlinear effects of the system. In order to achieve a good control response for this process, an accurate model has to be developed to design a robust controller that can follow the reference trajectory and track the setpoint changes smoothly. Also, the model has to be of the adaptive form so that the controller has the ability to reject any disturbances or noisy feedback.

Research on the Technology of Three-Dimensional Surface Topological Reconstruction of Underground Rock Salt Cavern Based on Sonar Detection Data

2012 ◽  
Vol 500 ◽  
pp. 218-225
Author(s):  
Jian Zhong Chen ◽  
Ye Hua Sheng ◽  
Yong Zhi Wang
Keyword(s):  
Rock Salt ◽  
Three Dimensional ◽  
Scientific Basis ◽  
Boundary Representation ◽  
Surface Model ◽  
Social Significance ◽  
Technological Support ◽  
Salt Cavern ◽  
Rock Salt Cavern ◽  
Dimensional Surface

After analyzing the characteristics of rock salt and the feasibility and importance of using underground rock salt cavern as energy stockpiles, this paper explains in detail about the principle of sonar detection technology in cavern measuring and its data organization. This paper studies the technology of three-dimensional surface topological reconstruction of underground rock salt cavern based on sonar detection data with half-edge data structure and boundary representation models. Meanwhile, by conducting validity check for constructed surface model and repair of possible defects, the paper finds correct and effective three-dimensional surface models of underground rock salt cavern, and provides effective data base for the stability analysis, creep analysis and other numerical simulations of underground rock salt cavern. This method, with important economic and social significance, can provide a scientific basis and technological support for the construction of caverns, especially for the safe and rational use of underground rock salt cavern.

Three-Dimensional Structure Trajectory Guiding Scan and Points Cloud Registration

2013 ◽  
Vol 300-301 ◽  
pp. 423-426
Author(s):  
Yong Cai
Keyword(s):  
Point Cloud ◽  
Structural Parameters ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Surface Model ◽  
Visual Measurement ◽  
Local Point ◽  
Inverse Kinematics Problem ◽  
The Relationship ◽  
Measurement Approach

Three-dimensional visual scanning is an advanced non-contact measurement approach that can obtain a complete surface model of object. But, in the method, the local raster point cloud sets calculated must be registered to a whole. To reduce fluctuating errors and increase efficiency, we propose a new method that scanner can be moved around object guided by pre-planning trajectory of the robot. First, considering the structural parameters of the robot, the Inverse Kinematics Problem of each joint rotating function is derived, and the moving trajectory is simulated. Then, the relationship between the distances of controlled motion and data gotten by scanner is analyzed, a transform matrix which registered the local point cloud sets is deduced, the raster data can be normalized to the world coordinate by it. The experimental results show that error of registration is less than 0.09mm. The method is suited to measuring different targets in robot workspace. It can improve the efficiency and flexibility of visual measurement system.

scholarly journals Dynamic polygon clouds: representation and compression for VR/AR

2018 ◽  
Vol 7 ◽  
Author(s):  
Eduardo Pavez ◽  
Philip A. Chou ◽  
Ricardo L. de Queiroz ◽  
Antonio Ortega
Keyword(s):  
Point Cloud ◽  
State Of The Art ◽  
Three Dimensional ◽  
Point Clouds ◽  
Polygonal Meshes ◽  
Triangle Meshes ◽  
Previous State ◽  
Temporal Redundancy ◽  
Inter Frame ◽  
Robust To Noise

We introduce the polygon cloud, a compressible representation of three-dimensional geometry (including attributes, such as color), intermediate between polygonal meshes and point clouds. Dynamic polygon clouds, like dynamic polygonal meshes and dynamic point clouds, can take advantage of temporal redundancy for compression. In this paper, we propose methods for compressing both static and dynamic polygon clouds, specifically triangle clouds. We compare triangle clouds to both triangle meshes and point clouds in terms of compression, for live captured dynamic colored geometry. We find that triangle clouds can be compressed nearly as well as triangle meshes, while being more robust to noise and other structures typically found in live captures, which violate the assumption of a smooth surface manifold, such as lines, points, and ragged boundaries. We also find that triangle clouds can be used to compress point clouds with significantly better performance than previously demonstrated point cloud compression methods. For intra-frame coding of geometry, our method improves upon octree-based intra-frame coding by a factor of 5–10 in bit rate. Inter-frame coding improves this by another factor of 2–5. Overall, our proposed method improves over the previous state-of-the-art in dynamic point cloud compression by 33% or more.

scholarly journals Flexible point cloud matching method based on three-dimensional image feature points

2018 ◽  
Vol 10 (9) ◽  
pp. 168781401879503
Author(s):  
Haihua Cui ◽  
Wenhe Liao ◽  
Xiaosheng Cheng ◽  
Ning Dai ◽  
Changye Guo
Keyword(s):  
Point Cloud ◽  
Three Dimensional ◽  
Point Clouds ◽  
Feature Point ◽  
Image Feature ◽  
Surface Measurement ◽  
Surface Model ◽  
Feature Points ◽  
Matching Method ◽  
Dimensional Image

Flexible and robust point cloud matching is important for three-dimensional surface measurement. This article proposes a new matching method based on three-dimensional image feature points. First, an intrinsic shape signature algorithm is used to detect the key shape feature points, using a weighted three-dimensional occupational histogram of the data points within the angular space, which is a view-independent representation of the three-dimensional shape. Then, the point feature histogram is used to represent the underlying surface model properties at a point whose computation is based on the combination of certain geometrical relations between the point’s nearest k-neighbors. The two-view point clouds are robustly matched using the proposed double neighborhood constraint of minimizing the sum of the Euclidean distances between the local neighbors of the point and feature point. The proposed optimization method is immune to noise, reduces the search range for matching points, and improves the correct feature point matching rate for a weak surface texture. The matching accuracy and stability of the proposed method are verified using experiments. This method can be used for a flat surface with weak features and in other applications. The method has a larger application range than the traditional methods.

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