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The flatness measurement of a large 2-D flat work- piece such as a satellite solar panel substrate is a key problem in its manufacturing process. Based on the current measuring methods and the actual engineering project, a new noncontact high-precision, low-cost large 2-D flat workpiece flatness measuring system is developed, in which the techniques of oblique optical triangle measuring structure, virtual measurement datum plane, and error self-correction are adopted. By means of the oblique optical triangle measuring structure that is first proposed, the measuring area and resolution of the measuring system can be greatly increased. Meanwhile, on the basis of the techniques of virtual measurement datum plane and error self-correction, the noncontact high-precision, low-cost flatness measurement can be realized on a nonprecise large metallic platform. Experimental results on the satellite solar panel substrate indicate the correctness and effectiveness of the proposed noncontact flatness-measuring system of the large 2-D flat workpiece. Although the specific application of the satellite solar panel substrate is presented in this paper, the proposed measurement techniques and measuring system could be applied independent of the nature or use of the large 2-D flat workpieces. [ABSTRACT FROM AUTHOR]

This paper describes a modeling language that aims to provide a unified framework for representing control systems, namely, physical plants coupled with computer-based control devices. The proposed modeling methodology is based on the cardinal principle of object orientation, which allows describing both control software and physical components using the same basic concepts, particularly those of capsules, ports, and protocols. Furthermore, it is illustrated how the well-known object-oriented specification language unified modeling language can be adopted, provided an adequate formalization of its semantics, to describe structural and behavioral aspects of control systems, related to both logical and physical parts. [ABSTRACT FROM AUTHOR]

This paper proposes a method by which material in- homogeneity may be taken into account in a reliability calculation. The method employs Monte-Carlo simulation; and introduces a material strength index, and a standard deviation of material strength to model the variation in the strength of a component throughout its volume. The method is compared to conventional load-strength interference theory. The results are identical for the case of homogeneous material, but reliability is shown to reduce for the same load as the component volume increases. The case of a tensile bar is used to explore the variation of reliability with component volume. [ABSTRACT FROM AUTHOR]