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31 August 2017, Volume 38 Issue 4 Previous Issue    Next Issue

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Adjustable Tangent Points Trigonometric Bézier Curve of Two Order with#br# Shape Parameters PENG Xingxuan, PAN Jing, CHEN Xuejiao, JIANG Xinxin 2017, 38(4): 463-468.  DOI: 10.11996/JG.j.2095-302X.2017040463 Abstract ( 134 )   PDF (393KB) ( 264 )   A trigonometric Bézier basic functions of two order with shape parameters are constructed. By using of position parameters, the adjustable tangent points trigonometric Bézier curve of two order with shape parameters is defined. It retains the properties of Bézier curve. Its shape and tangent points are adjustable. And it can accurately represent ellipse and circle. The curves are G1 continuous and the condition of curves blending is simple. Examples illustrate the method is effective for curve and surface design. Related Articles | Metrics

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Interacting Feature Recognition Based on AAG Expansion and Hint CHENG Bin1, REN Zhenhua2 2017, 38(4): 469-475.  DOI: 10.11996/JG.j.2095-302X.2017040469 Abstract ( 150 )   PDF (697KB) ( 236 )   To recognize interacting feature effectively and improve the recognition efficiency, a feature recognize algorithm was proposed based on AAG expansion and hint. By simplifying the AAG, the machining feature faces are considered only for recognition. And then the virtual features are added to construct the auxiliary constituent surface to complete the separation of interacting features. The differences of local sub-graph are enhanced by extending the edge properties of the sub-graph, which improves the recognition efficiency and quality. The feasibility of proposed algorithm was verified by practical experiment. Related Articles | Metrics

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Topology Authentication of 2D Engineering CAD Drawings Based on Hashing MA Xiaobin, YE Ying, SU Zhiyong 2017, 38(4): 476-482.  DOI: 10.11996/JG.j.2095-302X.2017040476 Abstract ( 105 )   PDF (535KB) ( 193 )   Since it’s difficult to authenticate the topological relation in the 2-dimensional engineering CAD drawing, a topological integrity authentication algorithm is proposed based on Hashing in this paper. Firstly, the algorithm extracts the topological relations of the drawings to generate the topology graph. Secondly, the components in the engineering CAD drawing are encoded, and the local topological quantization pattern (LTQP) is proposed to quantize the topological features of each component. Then, the components are divided into five categories according to their coding, and a Hash sequence is generated by discrete cosine transform based on the LTQP values. Finally, the Hash sequence of each category is combined to obtain the complete Hash sequence of the drawing. The experimental results show that the algorithmis robust to rotation, scaling and translation in engineering CAD drawings, and is vulnerable to the change of topological connection. By classifying the components to generate a Hash sequence, the algorithm can locate the type of components which is subjected to the topology attack. Related Articles | Metrics

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Tooth Modeling Method Based on Tooth Crown and the Features of Tooth Root LI Zhanli, GAO Tianyu, LI Hongan, WU Fanfei 2017, 38(4): 483-488.  DOI: 10.11996/JG.j.2095-302X.2017040483 Abstract ( 137 )   PDF (872KB) ( 269 )   Three-dimensional (3D) scanning technology and 3D reconstruction based on CT images are popular methods for tooth modeling recently. However, 3D scanning only can provides partial 3D data of tooth crown, and the data of gingival root wrapped by the gum cannot be collected. Using CT images for 3D reconstruction can get complete data model of tooth, but the process is time-consuming and costly. In order to overcome the weakness of these methods above mentioned, a novel tooth modeling method is proposed based on tooth crown and the features of tooth root. This method establishes association rules for tooth crow and root based on the measured data of tooth, and 3D model is constructed according to the Cardinal spline interpolation and Tangent weight - Laplacian mesh editing. Compared the modeling results and original data, experimental results show that the modeling method is efficient and feasible. Related Articles | Metrics

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A Ray Tracing Method of Splat-Based Surface Using Height Difference#br# Intersection CAI Peng1,2, SHI Ping1,2, FAN Yueyuan1,2 2017, 38(4): 489-496.  Abstract ( 106 )   PDF (1942KB) ( 174 )   The main drawbacks of current ray tracing methods for splat-based surface are coarse rendering effects in the parts of silhouettes and sharp features. A ray tracing method for splat-based surface is proposed based on the high computation function defined by blending projective distances between the point of ray and the corresponding splats. And the height difference is used as step length to compute iteratively intersection. The height difference function is closed to geometric features of splat-based surface. Experiment results show that the method has good rendering quality in the parts of silhouettes and sharp features, and high convergence rate as well as low computation cost. Related Articles | Metrics

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The Multidimensional Visualization of Radar Data WANG Xuan1, LU Mingyue1,2, ZHENG Jianqin1,3, LIU Bin1, MAO Yuanxiang1 2017, 38(4): 497-503.  DOI: 10.11996/JG.j.2095-302X.2017040497 Abstract ( 120 )   PDF (4948KB) ( 445 )   According to the spatial characteristics of radar data, the radar projection plane space and the radar stereo space are divided into two kinds of radar space to construct the lattice model, which provides model support for the multidimensional representation and analysis of meteorological radar information. Combining the surface information of the research area, the visualization development package VTK is used to realize the visual expression of the lattice model. Under the support of the model, the visual expression of integrated terrestrial information is no longer limited to the two-dimensional form. The three-dimensional representation can display the radar details more comprehensively, which is helpful for the meteorological personnel to study and analyze the structural characteristics of radar echo. Related Articles | Metrics

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An Effective Fracture Surface Segmentation Method of the Terracotta Warrior Block ZHAO Fuqun1,2, ZHOU Mingquan2,3 2017, 38(4): 504-508.  DOI: 10.11996/JG.j.2095-302X.2017040504 Abstract ( 95 )   PDF (666KB) ( 197 )   The Terracotta Warrior block is a rigid block with some thickness, and it’s fracture surface segmentation is an important work of Terracotta Warrior restoration. Aiming at triangular mesh data model of Terracotta Warrior blocks, an effective fracture surface segmentation method was proposed here. Firstly, the feature segmentation points were extracted by calculating the volume integral invariant of each vertex on surfaces. Secondly, the closed boundary lines were solved by minimum spanning trees algorithm and pruning strategy. Finally, all the surfaces were extracted and the fracture surfaces were distinguished from original surfaces. The experimental results showed that the proposed method could effectively complete fracture surface segmentation of the Terracotta Warrior block when the fracture surfaces were rougher than original surfaces. So the proposed fracture surface segmentation method is an effective fracture surface segmentation way of Terracotta Warrior blocks. Related Articles | Metrics

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Ergonomic Optimization of Heavy-Duty Commercial Vehicle Cab LIU Senhai1,2, LI Songtao1, CAO Shuwei1, LI Huan1 2017, 38(4): 509-515.  DOI: 10.11996/JG.j.2095-302X.2017040509 Abstract ( 143 )   PDF (2220KB) ( 363 )   Taking a heavy duty commercial vehicle cab as research objects, the ergonomic engineering characteristics of this cab is analyzed and optimization promotion targets determined by professional subjective drive and evaluation for ergonomics. The optimization design is analyzed by ergonomic analysis tools in CATIA, and optimization path and method are provided. After which ergonomic engineering characteristics of optimized cab is drove and evaluated subjectively again. Compared with original design, the ergonomics of cab after optimizing are improved a lot. All these analysis can provide some experience and way to ergonomic analysis and design optimization for heavy duty commercial vehicle cab. Related Articles | Metrics

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Batiks Patterns of Individual Preference Research Based on Eye Movement Data SHI Shifang, PAN Weijie, LV Jian, LIU Dan, LIU Zhenghong 2017, 38(4): 516-522.  DOI: 10.11996/JG.j.2095-302X.2017040516 Abstract ( 108 )   PDF (696KB) ( 230 )   The traditional personalized preferences are limited to sensibility analysis, and the user perceptual preferences of a particular product gotten. The sensibility analysis is subjectivity and instability, and the personal preferences are lack of scientific theoretical basis. The eye movement data is put forward a prediction method of users personalized. The multivariate regression equation is established based on the eye movement data and design elements. The patterns of the batik personalized user preferences are explored, and the weight of different design elements is gotten to obtained different solutions according to different user personalization. Related Articles | Metrics

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Target Edge Extraction of Remote Sensing Images Based on Non-Subsampled Shearlet Transform and Improved Mathematical Morphology WU Shihua1, WU Yiquan1,2,3,4,5,6, ZHOU Jianjiang1 2017, 38(4): 523-530.  DOI: 10.11996/JG.j.2095-302X.2017040523 Abstract ( 91 )   PDF (708KB) ( 211 )   In order to extract edges of target area more completely and accurately from remote sensing images, a method of target edge extraction is proposed based on improved mathematical morphology and modulus maxima of non-subsampled Shearlet transform. Firstly, the image is decomposed into high-frequency components with more edges and details and low-frequency component with fewer edges and minutiae through non-subsampled Shearlet transform. Then considering the property of coefficients of edge points under different decomposing conditions, the modulus maximum detection is performed for each sub-band of high-frequency components and the double-layer mask is adopted afterwards so as to get the high-frequency edge extraction result. Moreover, the low-frequency component is processed through the improved mathematical morphology method to get the low-frequency edge extraction result. Finally, the above two parts are fused and the final target edge image is obtained after removing the isolated points according to the regional connectivity. A large number of experimental results show that, compared with Canny method and four similar edge extraction methods, the detected edges by the proposed method are accurate, clear, complete and with abundant details. The method has strong anti-noise performance, which lays a better foundation for the following target feature extraction and recognition of remote sensing images. Related Articles | Metrics

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Side Information Fusion Algorithm Based on Reliability Evaluation in DMDVC XIONG Wenshi, QING Linbo, WU Xiaohong, CHEN Zhenzhen 2017, 38(4): 531-536.  DOI: 10.11996/JG.j.2095-302X.2017040531 Abstract ( 91 )   PDF (825KB) ( 181 )   In depth-based multi-view distributed video coding (DMDVC), the quality of side information is one of the key factors that affect the compression efficiency. In order to make full use of the temporal side information, spatial side information and depth map to improve the quality of side information of the DMDVC system, a fusion algorithm based on reliability evaluation is proposed. The motion compensated temporal interpolation (MCTI) is used to generate temporal side information, and then the spatial side information can be generated using the depth image based rendering (DIBR) technique. The object’s fast movement in the scene would affect the quality of temporal side information and the use of DIBR to generate spatial domain side information would lead to holes. To solve these problems, this paper selectively corrects the fast moving regions in temporal side information or the holes and edge regions in spatial side information. The experimental results show that the algorithm can effectively fuse the temporal side information and the spatial side information, which can achieve up to 5.6 dB improvement over [4]. Related Articles | Metrics

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A Single Image Super Resolution Algorithm Based on Reciprocal Cell Model ZHAO Liling1,2, SUN Quansen1, ZHANG Zelin2 2017, 38(4): 537-542.  DOI: 10.11996/JG.j.2095-302X.2017040537 Abstract ( 88 )   PDF (1258KB) ( 156 )   In order to improve single image resolution, a new algorithm based on the reciprocal cell model is proposed. First, based on the framework of example-based learning super resolution theory by Freeman, a pre-filtering step is introduced by reciprocal cell model. Then a corresponding relationship is established, within the feature enhanced low resolution image and the original high resolution image. At last, the super-resolution reconstruction is completed by using the trained correspondence. The characteristics of the low resolution image are enhanced after the new pre-filtering algorithm. The problems of “one-to-many” and “dimension difference” in training database between the low and high resolution image feature space is effectively weakened. Comparing with other algorithms such as bi-cubic interpolation, neighbor embedding and the example-based learning algorithm, our experimental results show that the new approach has better effect on subject image quality and PSNR index. Related Articles | Metrics

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Image Retrieval Based on Improved Color Histogram and Gray Level#br# Co-occurrence Matrix WU Qingtao1,2, CAO Zaihui1, SHI Jinfa1 2017, 38(4): 543-548.  DOI: 10.11996/JG.j.2095-302X.2017040543 Abstract ( 139 )   PDF (2263KB) ( 414 )   There are the problems that the extracted color feature is high dimension based on the traditional color histogram, and the direction of texture is neglected based on the traditional co-occurrence matrix. A new image retrieval algorithm combining the improved color histogram and gray level co-occurrence matrix algorithm is proposed. The K-means clustering is used to cluster the detected images in order to reduce the number of colors. The image codes are computed to form the color histogram based on vector codes in the HSV space. So the color features are extracted. The gray level co-occurrence matrix is used to extract the four eigenvalues of the detected image, and the four eigenvalues are combined with the weighting factor determined by the direction measure. The texture eigenvectors are obtained from normalizing the fused components. Finally, weighted average is used to fuse the feature distance of color and texture. Compared with the other two algorithms, experimental results show that our algorithm has higher recall and precision in general images and textured images. Related Articles | Metrics

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Video Fire Detection Based on Fusion of Multiple Features ZENG Sitong1, WU Haibin2, SHEN Peihui1 2017, 38(4): 549-557.  DOI: 10.11996/JG.j.2095-302X.2017040549 Abstract ( 152 )   PDF (889KB) ( 299 )   Video fire detection has important practical significance for fire safety. According to low detection rate and high false-alarm rate in the current flame detection algorithm, a novel method to detect flame is proposed, which combined flame motion detection, color clues and realized the multi-feature fusion based on the analytic hierarchy process (AHP). Firstly, the background modeling is carried out by optimizing the selective background updating to extract the fire-like moving region. Secondly, the color analysis technique is applied to extract suspiciousflametarget. Thirdly, study the dynamic features of flame and discuss detailed frequency property, angle, roundness characteristics, areagrowth and overall movement of the flame. Finally, a method of realizing the multi-feature fusion based on AHP for calculating the weight of the dynamic features of flame is proposed. The experimental results on the flame video library show that the proposed method is accurate and robust, which has high detection rate and low false-alarm rate. Related Articles | Metrics

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Image Inpainting Algorithm Based on Adaptive High Order Variation in Eight Neighbors XU Liming, WU Yajuan, ZHANG Bo 2017, 38(4): 558-565.  DOI: 10.11996/JG.j.2095-302X.2017040558 Abstract ( 89 )   PDF (1792KB) ( 388 )   To solve the problems of traditional variation inpainting algorithms, like insufficient information utilization, destroyed texture and strong artificial interference, an adaptive high order variational image inpanting algorithm based on eight neighbors is presented. Firstly, it makes full use of eight neighbors at the points to be repaired in damaged images and divides them into two groups of four-neighbor, then repairs images by nonlinear anisotropic diffusion in each four-neighbor respectively. The optimal value of parameter p in every four-neighbor will be determined by adaptive method. Then those points will be discreted through the central difference method. Finally, the Gauss-Jacobi Iteration of the damaged images can be obtained by using weighting and averaging. Compared with the image inpainting algorithms in recent years, the simulation results show that, the images obtained by the proposed algorithm have good evaluations. Not only is the repair time reasonable, but the texture structure is closest to the original images and values of PSNR or SA are the highest. Related Articles | Metrics

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Virtual Viewpoint Synthesis of Quick Remove the Distortion YAO Li1,2, LI Xiaomin1, HAN Yingdong1 2017, 38(4): 566-576.  DOI: 10.11996/JG.j.2095-302X.2017040566 Abstract ( 192 )   PDF (12386KB) ( 1466 )   Depth image based rendering (DIBR) is an effective method for virtual view synthesis. But synthetic images often contain distortion, the main problem is ghost effect and some holes of varying sizes. To cope with the ghost effect, the color correction of reference views is first used, and then two fusion methods are combined which are depth-based color image fusion and direct color image fusion. Inverse warping is adopted to fill cracks. In order to fill the remaining disocclusions, the image inpainting with depth map is used to get a better virtual view. Because the process of image inpainting is very time-consuming, the inpainting algorithm on GPU is implemented to accelerate the inpainting process based on compute unified device architecture (CUDA). Experimental results show that our proposed method improved the quality of virtual view synthetic images, and the image inpainting algorithm based on CUDA implemented also significantly reduced the time of hole filling. Related Articles | Metrics

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Research of Railway Vehicles Working Augmented Reality Simulating System WANG Weiming1, HE Yaxuan1, REN Bin1, ZHANG Yong2 2017, 38(4): 577-581.  DOI: 10.11996/JG.j.2095-302X.2017040577 Abstract ( 103 )   PDF (2620KB) ( 158 )   In view of lack of low-cost visualization simulation tools for simulation of complex conditions in the railway vehicles operation, a railway vehicles operation augmented reality (AR) simulation system based on OpenFrameworks is proposed. Firstly, the overall plan of the railway vehicles operation AR simulation system is introduced. Secondly, using OpenFrameworks powerful 3D model display, system modeling and image processing functions, the augmented reality simulation system based on improved AR code is structured. Lastly, railway vehicles dynamic running augmented reality scene is implemented and the experimental result is given. Related Articles | Metrics

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Application of BIM Visualization Technology in Foundation Pit Engineering YU Lina1, WU Mai1, GENG Huixuan2 2017, 38(4): 582-588.  DOI: 10.11996/JG.j.2095-302X.2017040582 Abstract ( 285 )   PDF (2351KB) ( 517 )   BIM visualization model is the core of BIM technology implementation. On the basis of summarizing the advantages of BIM, this paper further analyzes its specific needs of the foundation pit engineering construction. According to the characteristics and difficulties of foundation pit engineering in three groups of Haihe River, BIM technology is put into the project construction, and establish BIM model, launch the application of BIM technology, mainly for construction site layout optimization, complex technical clarification, quality inspection, data collection, process simulation, tec. Practice has proved that it has achieved good results. Related Articles | Metrics

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Research on BIM Component Library Based on IFC Standard ZHOU Hongbo1, SHI Pingwang2, DENG Xueyuan1 2017, 38(4): 589-595.  DOI: 10.11996/JG.j.2095-302X.2017040589 Abstract ( 150 )   PDF (608KB) ( 471 )   BIM technology has become one of the most popular fields in AEC industry, and various kinds of 3D software have been developed to support the design with BIM technology. However, due to the differences in data formats, the inefficiency in information sharing and exchange has occurred, and further may cause serious economic losses. Therefore, it is necessary to standardize and unify the data formats in BIM technology. The IFC standard is widely recognized as international standard for the BIM data. By researching on the IFC standard, the design scheme of the BIM component library and the methods for adding, modifying and deleting BIM components are proposed. Finally, a case study was introduced to demonstrate the design scheme’s feasibility of BIM component library based on IFC standard, which can provide a reference for the standardization and unification of data standards for BIM software. Related Articles | Metrics

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Correction Method of the Projection Images’ Rotational Center Based on Sinogram ZHAO Yuqing1, CONG Changhong2, HU Chunhong1, JI Dongjiang3, JIAN Jianbo1, QIN Lili1, SUN Mengyu1 2017, 38(4): 596-602.  DOI: 10.11996/JG.j.2095-302X.2017040596 Abstract ( 376 )   PDF (1506KB) ( 343 )   Affected by the precision of instruments and other factors, CT turntable may cause the deviation of projection center of rotation (COR), which will seriously affect the quality of the reconstructed images. Thus, the precise correction of COR in projection images plays an important role in the CT reconstruction. In this paper, a method of measuring the address of COR is proposed based on the radon transform, which is suitable for the parallel beam scanning model. The method can be summarized as follows: the COR address of the projection is obtained using one half of the mean of the 0° and 180° projections’ addresses in sinogram. According to the method, the data, which represent 0° and 180° projections in sinogram, were respectively copied by N times to get the image matrix A. The image matrix A was then segmented into binarization with the “Chan-Vese” method, and the 0° and 180° projections’ addresses of sample were obtained to calculate the COR address of the projection. Finally, the COR value was regarded as the center of the sinogram, and the sinogram was clipped properly in the horizontal direction. The simulation and experiment show that this method can accurately correct the COR, which effectively improves the quality of the reconstructed images. method can accurately correct the COR, which effectively improves the quality of the reconstructed images. Related Articles | Metrics

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Plagiarism Detection System for Software SolidWorks of#br# Students’ Assignment WANG Shuxia, JING Xiaoke, GAO Mantun 2017, 38(4): 603-609.  DOI: 10.11996/JG.j.2095-302X.2017040603 Abstract ( 239 )   PDF (535KB) ( 259 )   In order to prevent a student copying three dimensional CAD homework of others’ students, the detection methods for copying SolidWorks documents are taken for example to analyze. Firstly, all the possible copy methods of SolidWorks Documents are analyzed, and they can be divided into two types which are constant feature properties copy and inconstant feature properties copy. Then, different detection principles are proposed to the copy methods. Finally, this paper develops a checking system for all kinds of copy methods with C++ programming language. The system can read feature properties of SolidWorks documents, and compare their similarities to find the possible copies for teachers. The practical application proved that the system can prevent students from copying others’ documents efficiently. Related Articles | Metrics

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Research and Implementation of Interactive CAD Drawing Exercise Platform LIU Zhihong 2017, 38(4): 610-614.  DOI: 10.11996/JG.j.2095-302X.2017040610 Abstract ( 103 )   PDF (908KB) ( 225 )   In the field of CAD teaching, there have been many innovative teaching methodologies and software to help students understand abstract principle, complicated assemble procedures and forms, and students draw a complex engineering drawing easier. But until now, CAD drawing exercises of students do not much ground-breaking change. Teachers do not have enough time to carefully track every drawing steps and methods, and there is no possibility to correct their problems. An interactive CAD drawing experiment platform is developed. The interactive platform, on the one hand through the system automatically stores the student in the process of drawing the progress, so that teachers can understand the student's practice, and then provide a recommendation. And on the interaction between students and teachers, will also encourage cooperation between the students together to complete complex projects. Related Articles | Metrics

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The Application of Three-Dimensional Reconstruction Technique Based on Motion Parallax in AGV LUO Changping1,2, XIA Haibo1, ZHAO Qiong3 2017, 38(4): 615-622.  DOI: 10.11996/JG.j.2095-302X.2017040615 Abstract ( 90 )   PDF (14352KB) ( 85 )   The principle of motion parallax is used for achieving the three-dimensional reconstruction of scenes ahead with a single camera, and this process is expounded in detail by some geometric operations. The application of the reconstruction in indoor automatic guided vehicle (AGV) about processes of obstacle detection is researched. The traditional solution using some algorithms to divide the real-time image passed back by the camera into some accessible areas is improved to make obstacle information been of more authenticity and actual calculated meaning. Experimental results indicate that the proposed solution is of strong operability and enhances the obstacle detection ability of indoor AGV under the condition of a single camera, and has good robustness in different real environments. Related Articles | Metrics

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The Image Detection of Wheel-Rail Relative Lateral Displacement Based on Laser MA Zengqiang, WANG Yongsheng, SONG Zibin 2017, 38(4): 623-628.  DOI: 10.11996/JG.j.2095-302X.2017040623 Abstract ( 108 )   PDF (1960KB) ( 229 )   The position change of wheel rail contact point can directly reflect the wheel-rail contact. Aiming at the disadvantages of current camera monitoring method which is difficult to fully capture the position of the wheel rail contact point, a kind of wheel relative sliding image detection system is designed based on laser source. The system combines a camera with a laser source. The camera and laser source which keep a certain angle to the ground are installed on the bogie to convert wheel relative sliding into the inside rail surface laser spot extraction. The experimental results show that the system can real-time display and store the data of wheel relative sliding. And it has very important significance to the study of high speed locomotive stability and safety. Related Articles | Metrics