| EPS (Electronic Power Steering), a new safe, comfort, environmental protecting and energy saving steer, is hot in the worldwide automotive industry. It is also a new high-tech product published by national department. Because of the complexity of EPS components and the difficulty of modeling them, it takes a lot of time and huge amount of work to set up a 3D model on the software platform directly. In order to speed up the EPS development and improve the design efficiency, it is significantly important to develop a 3D parametric design system that fits EPS system characters very well. EPS system has a lot of power transmission devices that induces a large mount of design calculation. But these devices do have standard parameter and can be categorized according to their attributes. Based on these characters and using secondary development technology of UGII, we have developed a CAD system which fit to EPS very much , it can accomplish all these works—parameter calculating, structure designing, 3D parametric model setting up, assembling and motion simulating. Study of the key technology of secondary development also is done. This paper have accomplished these works:1. Illuminate the principle and features of EPS. Compare EPS with traditional Power Steering and analyze the development trend of EPS. Principle of Computer Assistant Design and its using on EPS design are discussed in this paper also.2. Form a general scheme base on the demand of the design, it is depend on secondary development mainly, combine with user order and make model base on UGNX directly. Set up construction of EPS 3D parametric design system and function module of software.3. Investigated the UG secondary development method thoroughly to master the whole development process. It includes researching the UGNX application interface based on VC++6. 0 design platform, customizing the main menu (MenuScript) and user menu (User Tools), visualizing the dialog window (UG/Open UlStyler), implementing multi-user interface.4. Investigated 3D parametric model design through UG/Open Grip. Setting and managing entity attributes, generating attribute file which match with CAPP/CAM at the same time.5. Assemble models automatically and research the application of UG WAVE function for assembling or modeling, the motion simulator and motion interference analysis scheme be investigated too.In order to fit to the demands of EPS development raised by Sanli stock limited company in Mianyang, we built and developed the special purpose CAD software - EPS assistant design system. This system can build parametric 3D model of most important parts of EPS and assemble automatically. It can save the working information like product number, material, coarse degree, tolerance, and so on at the same time of creating a model. This makes product CAPP/CAM working easier. This system uses UG menu, it is simple and easy to use. It also has a good interaction between user and system, and very extensible. It avails to improve efficiency and quality of EPS design. |
