Key Techniques Research On Auto-body Panel Die-design Platform Based On Grid

It is the times that the technique in computer science changes quickly, the distributed system is widely used, and people have been depended on the Internet gradually. Every country pays more attention to the application of the distributed computer cooperation in every industrial field. Meanwhile the automatic industry is the dominant part in all industries. Nowadays, not only at home, but also in the whole world, can none of a company in die making finish the task, which is to make the die of whole vehicle in a limited period. But a virtual company can make it come true on a CAE truss with distributed cooperation technique through the network. It can split the process of design the large quantities of high precision die designing on bodywork. Each group only designs the part, which it is good at in different place. On the whole, each part is designed by computer supported cooperation work so as to keep the same step in precision and progress, and then assembled to be a figuration by the virtual company to assist forming technique analysis. In 1990's, the grid technology became hot. Grid makes the resources that belong to different organizations virtual, and we can use all the resources in the Internet as to be using a computer. In all kinds of virtual environments, the grid system makes the resources that heterogeneously distributed to map to a single system. By this way, the developers can focus on the logic itself other than how to use the distributed resources. The virtual resources of the grid are appeared in the form of the services. To application developers themselves, they are faced to all kinds of services that can assure the quality of the service. Through these services, they can construct the required applications conveniently which can be abstracted to new services. This service system, which is growing, is the character of the grid. To close coupled distributed system, gird is a distributed system that is built on the public network and realized by the public protocols, so it is more distributed and open. Comparison to Internet, grid has abundant resources and behaviors of the resources, it also has better cooperation and has efficiency in accessing. Now the grid technique is developed to standardization, hybrid technique, large-scale and commercialization. Every country is busy to do some research on grid with great fortune. According to the theory of" the theory and method of die design of car body ", we choose a base environment which has wide development prospect, supporting heterogeneousness, and has the advantage of open and security .On this foundation we build the grid application of Auto-body panel Die-design at a large scale, and based on it, we design the grid running environment of Auto-body panel Die-design, which will be an important measure in die-design domain of automobiles .To apply the environment in the mechanism design platform based on grid will be the new explore and the new application in the industry of the mechanism of our country. It is also a useful chance for the auto industry to be stronger and to be of much cooperation. This article is based on a design platform model, which runs in the Internet, using grid technology, and supporting application of CAD/CAE/CAM. We developed some grid computing and case library applications in the grid environment combined automobile die design, and verified feasibility and validity of the platform with our practical results. The whole platform is focus on Globus, intimately combining the design procedure of the dies, and it offers a highly safe, reliable, available and performance design platform. 1. AAA security proposal based on grid The environment of net platform has Internet as the way of communications, the inside topology of most of nodes can be kept constant, so the design of dies and scientific research done before can be continue; leaf nodes adopt B/W/S mode inside, so this increases the safety of the whole system, making professional technical personnel relieved from computer operation knowledge, meanwhile, it reduces the requisition of hardware devices. The most of die design environment (design nodes) now set up grid not adopting the ways of grid, Globus offers proposal of attaching network only for design nodes, not for none-grid environment resources inside design nodes, thus shield a lot of resources and services; and limit the possibility of a part of clients visiting gird resource from none-grid environment. Globus uses certificate to authenticate, shielding the possibility of clients without certificate to obtain grid resources, this limit the designers to know more requirement of grid resource. So the platform adopts the proposal of Web Server + Grid, offering well support for clients, and setting up a complete way of authentication, it resolved the limit of Globus. According to the resources and services types the platform offered, we bring forward an encryption technology to control method of pay for consult services and for resource requirement services, we adopt to draw from log, and bring up an accounting method using resource + service. Combining reputation degree function, influence function, and acceptance time function, we improved resource authentication mode of Globus, bindingconsumers of services to make use of resources orderly, abstemiously and reasonable. Based on Authentication, Authorization and Accounting model of grid, this builds a safe model of AAA, assuring the platform to run orderly and use effectively. 2. The schema of grid computing combined with Auto-body panel Die-design. The procedure of the pressing and the molding is a complicated physics procedure interfered with three non-linear procedure coupling with each other, which are geometry, physics and borderline conditions, and the factors affect it are so many. The technique of computing and simulation for the pressing and the molding is a hot topic of multi-knowledge, including the science of material, the science of stretch computing power, the finity unit, the computing and the analyse of the numerical value, the theory of the material shaped, the craftwork and the equipment of the pressing, the design and the making of the model, the geometry of the sculpt and the computing graphics and so on. So it is a technique, which is very difficult. The analyse data and the computing of the pressing and the molding is very large, to utilize the abundant resource of the grid, the cycle of the study of the distributing high efficiency computing can be shorten greatly. A schema combined AAA and Accounting is established on the platform. The explore, the response center, the resource management center and the resource schedule center work together to transfer the resource in the grid to supply with high efficiency computing schema for the users. The platform adopts running mode, which combines resource management center with Index Service of Globus, realizing the function of obtaining the information of the nodes dynamically for the Web +Grid, adopting the resource management center and the Index service of the Globus. It supplies the resource schedule center and the counting with the credible evidence. According to the price mechanism of the market, the theory of parallel project and customer psychology .the platform simulate market process environment, which was controlled by price mechanism and put forward high QoS economic distributional strategy, it can assure high efficiency and at the same time lessen cost for users. The platform also provides resource booked strategy in order to make sure that customer need can be satisfied successfully. 3. The application of case library based on grid The design methods, which are based on case library, come from the hot technique "case reasoning" in AI. Case reasoning is also a widely used method in CAD. Case library is also an expert knowledge system and the set of expert's experiences. We can build a huge expert case library system by using the openness and distribution of grid. The case library, which is based on grid, is a logical set of the entire node case base in grid. Case library is integration for the user and the user does not need to know the organization form and physical distribution of the case library.