Dingfang Chen

Research on Distributed Multi-Screen Overhead Crane Simulator

This paper describes the development of an overhead crane simulator system targeted to operator training and examine. The virtual overhead crane model were made by 3DMAX with its real dimensions, and be export as IVE data Format which can be used OSG (OpenSceneGraph) 3D engine to control its inner relative mechanism motion. And distributed Multi-Screen display technique of visual system is used to afford high quality video with wide angle of view. Using hardware and software to realize the interactive response between operator and virtual scene. And these response simulations can optionally be stored as animations, and can later be played back, modified, filmed from different viewpoints. An overhead crane simulator is implemented successfully and is used to train new motormen who can be easier to control real cranes after training.

Design and Realtime Simulation of Rain and Snow based on LOD and Fuzzy Motion

This paper has studied the basic principles to generate special rain and snow rendering effects using particle systems. To overcome the problem that the system operation efficiency are currently low in the simulation process, an optimization strategy is proposed which combines Level of Detail(LOD) and fuzzy motion technologies. The point eidolon technologies are used to enhance the rain and snow rendering effects based on GPU acceleration technology. To make the simulation effects more vivid, texture mapping among various types was studied while the winds aerodynamic affects on rain and snow are taken into account By the help of the OSG three-dimensional engine, we designed a special effect dialogue box interface to make adjustable the particle parameters, including its magnitude, speed, texture switching, etc. More vivid simulation effects for the falling rain and snow are thus easily achieved as the relevant parameters can be dynamically adjusted through the purposely-designed interface.

The Virtual Design and Assembly of A Multilevel Planetary Reducer

This article mainly introduced carries on the multilevel planetary gear reducers virtual design process in the oil drilling platform raising mechanism using the computer virtual prototype technology. The paper on complex mechanical design in a virtual assembly process of the problems has carried on the introduction. In the paper appears question after analytical study has given the theoretical calculation formula and the practices two corresponding solutions. The examples proved that these methods are effective. These methods have the bigger reference value to the similar complex mechanisms virtual prototype design.

A development method study of rapid generating complicated 3D parts

In this paper, the present three dimension machine elements design methods were studied. The development strategy and concrete method of the using integration methods design complex three dimension parts based on the study of design method have been put forward. The system has been actualized, and the three dimension solid model of gear can be established just once from design condition and demand. The design efficiency was heightened, and the design quantity was improved. The design thought and method presented in this paper has bigger reference value to developing the complex three dimension solid elements.

Study on simulation technology applied in virtual surgery of peritoneal membrane

Based on physical properties of peritoneal membrane tissue, Mass Spring Model, which is fit for simulating the deformation of peritoneal membrane tissue in virtual surgery, is built in the paper. Then three numerical solution methods of this model are compared and analyzed to furthur put forward another simulating and modeling method, which is more reasonable and reliable. Also, problems of new models collision detection and collision response are raised. The model is solved by quasi-static method to get steadier and more realistic simulating effect of deformation, and then to lay the foundation for furthur simulation of peritoneal membranes virtual surgery.

Research and application of Web mining based on Web service

This paper presents the data mining system model based on Web services to solve the problems such as the deficiency of expansibility and the high cost. Simultaneously the model is better to adapt to the variability and dynamics of customers requests. According to the strong encapsulation and extensibility in Web Services, the model is more flexible and it enhances the performance greatly. Through the practical test of the models feasibility in this project, this thesis further details a higher efficiency, implementation and reusability comprised in the proposed model.

Soft body cutting simulation based on a new tetrahedralization method

A finite element method is used to simulate the deformation of soft body. The crucial procedure of cutting simulation is the geometry remeshing. During remeshing, the inner topologie consistence need be considered. Previously, a large number sub-tetrahedral is used to avoid the consistence problem or an additional algorithm is used to check and adjust the geometry to keep its consistence. In this paper we present a novel method with minimal elements to guarantee the geometry consistence during tetrahedralization. And when the edge cut is close to an existing node, then just split the node instead of cutting the edge, which avoids small tetrahedra generated and significantly improves the stability of numeric solution.

The Acquisition of Tooth Profile Curve Based on Image Recognition

Gear wear is a common failure mode of gears transmission. Their usual monitoring methods are influenced by the machine suffered the load, lubrication conditions and other factors. These factors affect the accuracy of monitoring. Therefore, use image recognition technology to overcome these deficiencies, research on diagnosis of gear wear. Studies obtained a better method of gray cutting which can enhance the gear profile, the tooth profile curve of geometric correction methods and formulas, tooth profile curve extraction of the optimal algorithm, and carried out the discrete studies of that extracted tooth profile curve, and made the research of extraction tooth profile curve discretization, as well as a comparative study with the curve which obtained in the analysis method. The results show that the method can obtain the satisfactory actual gear profile curve, obtained the comparison curve is more accurate, intuitive, easy to carry out comparative research, further through the image recognition to determine the degree of gear wear failure to provide possible.

Distributed Display technique Based on Virtools

Using distributed display technique, scene can be divided into several parts from different angle of view. When they project to different screens, the multi channel display effects can be achieved, and it is possible to simulate specified interactive virtual reality environment with high immersion. According to the specialty of virtual driving simulator, adopt the construction technique and components configuration technique of multi-screen display, and realize two kinds of projection screen system, CAVE and CYLINDER. Finally, a three channel virtual driving cab is developed by the technique mentioned above, and a high immersive virtual driving environment is founded, in which the liquid screens represent the windows of automobile. Comparing with related technology at home and abroad, the Studies have the features of good demonstration result, low cost and easy to use.

Research of the Model of Distributed E-Commerce Based on Grid Services

As the development of e-commerce, many new e-commerce models, such as B2B2C, are emerging. In the traditional e-commerce environment, when customers search for certain merchandise, they have to visit different websites time after time because of the lack of a unified and integrated center of e-commerce. On the other hand, many distributed business resources can not be shared sufficiently and efficiently, such as business logic services. The paper first introduces a new distributed e-commerce model based on grid service. The model supplies a platform of access to business data and business resources with a unified form, which facilitates e-commerce clients. The technology and principle related to the model are researched deeply, including the model of semantic transform based on XML technology, the model of data integration based on OGSA-DAI and the mechanism of sharing distributed resources based on grid services Finally it presents a frame of a simple instance.