Table of Contents

24 February 2012, Volume 33 Issue 1 Previous Issue    Next Issue

---

For Selected:

Download Citations EndNote Ris BibTeX

Toggle Thumbnails

Select

Research on function-model format language and FFL model Liu Xiaoping, Chen Xin, Lu Qiang, Tang Yiming, Lu Jingting 2012, 33(1): 1-6.  Abstract ( 83 )   PDF (254KB) ( 192 )   Function model is the kernel processing object of the conceptual design. First, a function-model format language (FFL) is proposed based on the analysis of function tree and extenics function model. The reatures of FFL are summarized and the definition and grammar are given. Second, an algorithm of conversion from extenics function model to function tree is put forward. Lastly, an example testifies the important role of FFL in promoting the connections among function models. Related Articles | Metrics

Select

Research on design method of winch driven by contactless magnetic coupling under deepwater Zhang Bo, Wang Zhuo, Zhang Baizheng, Wu Lei 2012, 33(1): 8-14.  Abstract ( 65 )   PDF (345KB) ( 202 )   A design method of the winch driven by contactless magnetic coupling is researched for the core purpose of the turning shaft sealing in a deepwater environment. This method has six design phases, including domestic and foreign information query and retrieval, graphic analyses of relevant structures, innovative design of 2D assembly sketches, a theoretical computation of structure parameters, the 3D modeling and motion simulation and engineering drawing. This method is of generality, which can provide examples for the post-graduate students and engineering personnel in self-renovation design of scientific research. Related Articles | Metrics

Select

Application of propeller drawing based on computer aided drawing Liu Sheng, Zhang Limin 2012, 33(1): 15-18.  Abstract ( 104 )   PDF (309KB) ( 298 )   The propeller automatical drawing is obtained by using the secondary-development technology VBA of AutoCAD. The method and basic steps to achieve drawing of propeller are introduced, especially the drawing of expanded outline, project outline and side projection. And the computer aided design system of conventional propeller is developed on the base of it. The system can improve the efficiency of design and find a new way to plot marine propeller exactly and effectively. Related Articles | Metrics

Select

Adaptive optimization technique of engineering drawings in 3D environment Lu Chunyue, Wang Zongyan, Guo Xing, Yu Guojun 2012, 33(1): 19-14.  Abstract ( 78 )   PDF (593KB) ( 215 )   Engineering drawing is an important basis for production, so it’s necessary to optimize the 3D engineering drawings to meet enterprises’ requirements. An adaptive optimization principle based on model templates and engineering drawings templates is given by using the correlation between the model and the drawings. Principles of template customization are put forward; the methods with ordinary and special customization are presented to lay the foundation for the subsequent optimization. Several key technologies of adaptive optimization are discussed, including view positioning, scale matching, dimension positioning and part-list optimization. And finally a satisfying engineering drawing of large complex assembly is obtained. Related Articles | Metrics

Select

Two kinds of trigonometric curves with shape parameters Yan Lanlan, Liang Jiongfeng, Huang Tao 2012, 33(1): 25-30.  Abstract ( 70 )   PDF (272KB) ( 174 )   Two kinds of trigonometric curves with shape parameters are defined, they are trigonometric polynomial curves and cubic trigonometric spline curves. The former retains the main properties of the quadratic Bézier curve, and it is closer to the control polygon and can achieve higher order of continuity than the quadratic Bézier curve. The latter is similar to the quadratic B-spline curve, each piece of it is generated by three consecutive control points. For equidistant knots, the curves are C2 continuous, and they are C3 continuous under special conditions. Related Articles | Metrics

Select

Study on formation mechanism of product style and decision-making process in design based on information entropy Chen Li, Zhou Haihai 2012, 33(1): 31-37.  Abstract ( 89 )   PDF (364KB) ( 219 )   The information theory method is introduced into the field of product form design. The formation principle of a certain product form style and the decision-making points in design are analyzed through the calculation of the information coefficients of every two form variables. Taking two styles of finance equipments as examples, the representative product samples are selected, the style feature variables are extracted, and the information entropy of every variable and the information coefficients of every two variables are calculated. Then the formation mechanism of the target styles and the decision-making process in design are summarized. The examples prove that the method proposed is feasible and can provide effective reference to form design. Related Articles | Metrics

Select

Research on the design and key technology of product family based on genetic engineering ideas Gao Lei, Wan Jing, Chen Dongning 2012, 33(1): 38-43.  Abstract ( 94 )   PDF (241KB) ( 234 )   By analyzing the inheritance relationships of the size and the shape feature of the profiles, and the structure variation of profile model, the idea of genetic engineering is used in the development and design of product family, and the profile feature is taken as the DNA of the product structure information. The propagation of the profile feature, as information streams, in product tree is revealed referenced to the principle of genetic engineering of biology. On this basis, a method of gene coding and gene recombination for product based on the idea of genetic engineering is provided. By discussing the concept of product family and product gene DNA and the connotation and the research contents of the designing of product family DNA, the key support technologies of genetic engineering are pointed out. To take the door profile’s structural for an example, the result shows the designing effect on the idea of genetic engineering of the product family. Related Articles | Metrics

Select

Multilevel graph cuts for fast image segmentation Jiang Jianguo, Zhang Jie, Zhan Shu, Guo Yanrong 2012, 33(1): 44-49.  Abstract ( 82 )   PDF (586KB) ( 272 )   Graph Cuts (GC) is a novel image segmentation method based on graph theory framework. The innovations of this theory lie in its global optimization and the unity of knowledge. However, if the image is large, computation will be very time-consuming. This paper presents a GC-based Hierarchical image segmentation method. First the initial segmentation is obtained through GC in the low-resolution with a very low computational cost. Then the contour is projected back to the high-resolution image to construct a narrow band. At last accurate segmentation in the narrow-band is achieved by using of matting arithmetic. Experimental results show that this method can ensure the accuracy of segmentation results with a significant increasing in computing speed. Related Articles | Metrics

Select

Using improved weighted parabolic interpolation and wavelet transformation to zoom images for super-resolution Cai Nian, Zhang Haiyuan, Zhang Nan, Pan Qing 2012, 33(1): 50-55.  Abstract ( 64 )   PDF (991KB) ( 182 )   In order to preserve the basic information of images and to improve their visual performance and space resolution, a novel image zooming algorithm is proposed by using improved weighted parabolic interpolation and wavelet transformation which incorporates the error-amended part into the classical weighted parabolic interpolation algorithm. Directions of interpolation points are determined by the Sobel operator, then a preliminary zoomed image is obtained. High-frequency components are got by a wavelet transformation, and low-frequency components are replaced by the enhanced amplitude of the original image. At last, a high-resolution image is achieved by inverse wavelet transformation. The experimental results indicate that, compared with traditional image zooming algorithms, this algorithm can get clearer and sharper edges due to considerations of global pixels correlation of the original image. Related Articles | Metrics

Select

A novel method for virtual walkthrough using polygonal panoramic mosaics Wang Haiying, Qin Kaihuai 2012, 33(1): 56-62.  Abstract ( 98 )   PDF (5975KB) ( 233 )   A new method of virtual walkthrough using image-based rendering with polygonal panoramic mosaics is presented. First, we take pictures and get multiple panoramas with ordinary handhold camera along a route or in a square region. Second, we use SIFT feather points detection to get slim images with depth which can be used in interpolation for the rendering of new view point. The algorithm proposed in this method is very efficient for virtual walkthrough in the large outdoor scene. The construction and rendering process with multiple panoramas is easy to implement and the data capturing is simple without expensive equipments. Related Articles | Metrics

Select

Image edge detection technology based on Daubechies wavelet Mao Anding, Guan Yihong, Duan Rui, Wang Yanhua, Lü Liang, Ji Yunhai 2012, 33(1): 63-67.  Abstract ( 113 )   PDF (281KB) ( 253 )   In this paper, an image wavelet transform is conducted by using the features of Daubechies orthogonal wavelet and the Mallat multi-scale analysis method. The image is decomposed into four parts of a low-frequency contour, the horizontal high-frequency, the vertical high-frequency and the slash high frequency. Because the image edge mainly concentrates in the high-frequency parts, the high-frequency wavelet coefficients are reserved while low-frequency wavelet coefficients are conducted of wavelet transform again, extracting the second high-frequency signals from low-frequency contour parts. Finally, the maximization of edge information of image is achieved in extraction by use of inverse transformation of the high-frequency wavelet coefficients and the second high-frequency wavelet coefficients. Related Articles | Metrics

Select

3D model reconstruction of external thread based on image processing technology Wan Peng, Jiang Lijun, Chen Xuedong, Li Zhelin 2012, 33(1): 68-72.  Abstract ( 106 )   PDF (402KB) ( 272 )   This paper proposes a method to realize 3D model reconstruction of thread pieces based on features of multi-angle sequence images. Firstly, multi-angle sequence images of thread pieces are acquired on rotating platform, and feature points are extracted from each image, then 3D transformation and interpolation are conducted to feature points, and finally 3D model is realized. The experiment results show that this algorithm can accurately realize 3D model reconstruction of thread pieces with high presicion. Related Articles | Metrics

Select

The object-oriented classification of high resolution images with spectrum analysis Su Xiaoyu, Gan Fuping, Wan Lifei, Liu Shaofeng 2012, 33(1): 73-79.  Abstract ( 92 )   PDF (552KB) ( 240 )   With the improvement of remote sensing image spatial resolution, the spatial information of ground objects is more abundant, the ground objects’ size, shape and the relationships between adjacent ground objects are reflected better. As a result, high resolution image classification methods are currently more emphasized on using spatial information and many artificial subjective factors are participated in the classification process. In the abandoned area it is difficult to interpret. Too much fine segmentation causing plenty of operations is another difficult problem of high resolution images classification. The object-oriented classification of high resolution images with spectrum analysis is put forward as follows: SAM is firstly classified roughly with mask operation, and then fine object-oriented classification is conducted. That solves better the problems of type uncertainty of ground objects and too much fine segmentation in object-oriented classification. The river and road of the Tibet naqu area are extracted with eight bands WorldView2 data of 0.5 meters spatial resolution and accuracy reaches 96.6%. Related Articles | Metrics

Select

The research of astronautics simulation based on virtual reality technology Cui Shanjun, Tan Dunming, Zhao Gang 2012, 33(1): 80-86.  Abstract ( 67 )   PDF (514KB) ( 242 )   Astronautics simulation mainly focuses on multimedia simulation and scene simulation currently. However, the immersion is limited. An astronautics simulation system is developed to solve this problem with virtual reality technology. The system is based on tiled-display technology and a series of open-source software. According to the application demand, separated display mode and combined display mode are developed to detach data computation and visual display. The system has advantages in portability and immersion. Related Articles | Metrics

Select

Application of virtual reality in VRML-based assembly visualization Liu Yang, Shao Wei, Wang Jing, Shi Geya, Tang Chuanling 2012, 33(1): 87-90.  Abstract ( 95 )   PDF (422KB) ( 236 )   The process of virtual assembly is achieved on computer and three dimensions visible virtual scene is established by VRML. A method of constructing virtual reality based on the VRML and Java is offerproposed. It can strengthen the interaction between VRML virtual scene and outside, meanwhile, a specific technique on how to implement the virtual assembly with cartoon demo on the network is brought forward with an example. This method can not only be used to show the visible assembly in network environment, but also be applied to the scientific visualization based on VRML in other fields. Related Articles | Metrics

Select

Mesh segmentation of animation characters under the skin restriction Li Lin, Xie Wenjun, Liu Xiaoping 2012, 33(1): 91-97.  Abstract ( 81 )   PDF (484KB) ( 284 )   The efficiency of design in production of game and movie can be improved through the reuse of the animation characters data, which can also bring the diversification of characters. A division method under the skin restriction is presented, which aims at mesh segmentation——the first step of model reuse. The newis method gets the pre-segmentation results based on the motion relativity of the skin information firstly, then processes the results by topologic check and optimization calculation, then obtains the mesh parts adapting to blending of animation characters finally. After someThe new method is tested given on theusing the models from game company, the testing results confirmshowed that thise new method is simple and effective. Related Articles | Metrics

Select

Research on synchronous modeling in engineering graphics teaching Huo Guangqing, Zheng Change 2012, 33(1): 98-5.  Abstract ( 71 )   PDF (276KB) ( 217 )   The synchronous technique is a new 3D modeling one and its application in the engineering graphics teaching is the research focus of this article. Through analyzing the synchronous modeling technique and the contents of engineering graphics, the ways and methods of applying this technique in teaching are obtained. The results show that the technique of steering wheel in synchronization is a very flexible modeling tool, which can be used for modeling and editing of intersection line and cutting solid, and for the translation and rotation of basic characteristics and surface. Using synchronization draft regional recognition, modeling is more flexible and it can significantly improve student’s learning interests in the teaching practice of drawing reading, modeling and projection. Related Articles | Metrics

Select

Discussion on the teaching of many-class-hour mechanical drawing course with 3D CAD Shu Hong, Gao Fei, Cheng Xia 2012, 33(1): 103-106.  Abstract ( 76 )   PDF (401KB) ( 245 )   For the combination of the traditional many-class-hour mechanical drawing teaching with 3D CAD, its features are analyzed, the drawing representation methods different from projection are concluded, and a two-step combination method is proposed: the first step is combining 3D CAD with traditional drawing contents with a mutual support to each other, and the second step is the independent teaching mainly with 3D CAD. Moreover, with the help of teaching practice in 3D modeling with Iinventor, students can enhance their capacity in mechanical drawing representation, innovation thinking and constructing to fit the demand of modern design and manufacture. Related Articles | Metrics

Select

The graphics curriculum reform of higher vocational education based on generalized geometric shape analysis Liu Haiqiong, Tan Jianrong 2012, 33(1): 107-112.  Abstract ( 61 )   PDF (413KB) ( 198 )   The generalized geometry shape analysis method, with which the core contents of the engineering graphics curriculum are divided into five modules, i.e. geometric elements, geometric structures, functional structures, component assemblies and knowledge and skills, is believed to be an exploratory and innovative method for the curriculum reform. The engineering graphics curriculum reform scheme based on the generalized geometry shape analysis method for the higher vocational education and its key points for the realization are introduced, preliminary exploration and practice have been conducted and good results are achieved. Practice results show that this method can effectively enhance the teaching effectiveness for the graphics basis and its applications, and is helpful for the rapid occupational adaptation, the logical thinking formation and the development of the innovation capacity. Related Articles | Metrics

Select

Local interference detection and avoidance in five-axis machining of complex surfaces Du Juan, Yan Xianguo, Tian Xitian 2012, 33(1): 113-121.  Abstract ( 61 )   PDF (383KB) ( 183 )   This paper presents a methodologymethod of an automatic detection and elimination of local gouging for five-axis complex surface machining with a fillet-end milling cutter based on the technique of curvature matching and grid points. Firstly, a diameter of milling cutter is chosen by complete curvature matching to ensure un-gouging at any cutter contact point along any direction, and the first inclination angle of cutter can be determined by comparing the minimum principal curvature of cutter with the maximum principal curvature at each cutter contact point. In order to detect if a rear gouging occurs at the adjacent domain of contact point, the grid points is employed to form detection area and candidate detection points. A method to choose valid detection points from candidates and the technology of detection and avoidance of local interference are presented in detail in this paper. Finally, the validity of proposed method and algorithms are testified by an example of non-uniform rational B-spline surface. Related Articles | Metrics

Select

Research on axisymmetric aspheric surface machining model Zhang Xuechen, Cao Guohua, Nie Fengming, Wu Qingtang 2012, 33(1): 122-126.  Abstract ( 58 )   PDF (520KB) ( 177 )   Due to axisymmetric aspheric surface elements’ their excellent optical performance , axisymmetric aspheric surface elements therye are occupyingpossessing more and moreincreasingly bigger utilization proportion in modern optical system. The high processing quality and machining precision make greater challenges for optical components manufacturing. This paper aims at diamond wheel machining requirement of axisymmetric aspheric surface machining system, proposes a reasonable theory scheme, provides an appropriate geometrical model, and verifyies the reliability of scheme through dynamic simulation, provides reliable parameters for popular processing process. Related Articles | Metrics