Zhong Yi-fang

A systematic design and evaluation method for output characteristics of epicyclic gear trains

The aim of this article is to provide a systematic method to perform probabilistic-fuzzy design or evaluation for epicyclic gear trains (EGTs). Based on investigation of the probabilistic-fuzzy characteristics (about kinematics and dynamics) which are originated by manufacturing errors and assembling deformation of EGTs, the key performance indexes of EGTs that include kinematic accuracy, dynamic accuracy are analyzed. The probabilistic mapping relations between input parameters and output characteristics of EGTs are established on the basis of systematic design point. Furthermore, these design processes for improving performance are induced as some bilateral-fuzzy events. The new design criterion is presented for these key performance indexes of EGTs. So the fuzzy-reliability model for design or evaluation of EGTs is built. Finally, an example is discussed to apply the method.

Unified Modeling of Complex Real-Time Control Systems

The complex real-time control system is a software dense and algorithm dense system, which needs modern software engineering techniques to design. UML is an object-oriented industrial standard modeling language, used more and more in the real-time domain. This paper first analyses the advantages and problems of using UML for real-time control systems design. Then, it proposes an extension of UML-RT to support time-continuous subsystems modeling. So we can unify modeling of complex real-time control systems on a UML-RT platform, from requirement analysis, model design, simulation, through to code generation.

Design and implementation of an integrated CAD/CAPP system based on PDM

Product data management (PDM) is a new technique that is developed from database management system (DBMS) to manage the information and the associated procedure of a product. Many design engineers have employed PDM tools to coordinate and control access to documented versions of product designs. But it is still a focus of research efforts in industry and academic how to further build an efficient and effective integrated product/process development environments (IPDEs) based on PDM to meet requirements of enterprises. This paper introduces the approach to design and implementation of an integrated CAD/CAPP system (IC2S) based on PDM. This system is an important compent of computer integrated manufacturing system in KELON Inc(Kelon-CIMS). It is mainly used to support for the design and development of the home electric appliances (HEA).

Virtual Facility Layout Design Using Virtual Reality Techniques

Manufacturing facility layout design has long been recognized as one of the most critical and difficult design tasks in manufacturing industries. Traditional layout methods can not fully solve this complex spatial layout problem. Virtual reality (VR) is a new form of human-computer interaction, which has the potential to support a range of engineering applications. This paper discusses the reasons why manufacturing facility layout design is considered to be an appropriate new area of VR utilization. A VR-based layout design framework is proposed. The virtual environment construction issues are discussed. An example of the immersive VR application of facility layout is examined.

Vibration analysis of segmented shells coupled with liquid using a mixed FS-BE method

An analysis is presented for the coupled vibration of segmented shells submerged in or filled with liquid. To improve computing efficiency, the finite strip (FS) technique was used to analyze the segmented shell. As for the liquid area, a special boundary element (BE) was proposed. Compared to the classical boundary element method (BEM), this BE not only guarantees the continuity condition on the liquid-shell interaction plane, but also has fewer unknowns. By using Bernoullis law and the continuity conditions on the shell-liquid interaction plane, the influence of liquid area was simplified to an added mass matrix; therefore, the shell-liquid systems governing equations, shells FS equation, and liquids BE equation are decreased to a group of refined equations that has the same form of FS equation with a modified mass matrix. The method has been applied to a typical segmented shell-liquid system, and the natural frequencies, mode shapes, and response of vibration were calculated numerically. It shows that the method shown here has good efficiency and precision in computing and can analyze the arbitrary rotating shell-liquid system easily. *Communicated by Z. Mróz.