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A method of modeling the radiative energy transfer, which takes place during the transient of joining two concentric, semitransparent glass cylinders, is presented. The transient temperature field is computed using both the Discrete Ordinate Method (DOM) and the widely used Rosseland's approximation.

Motivated by the need to investigate thermal effects on the deflection and stresses in a thin-wall workpiece during machining, the thermal problem is modeled with an axisymmetric input to emulate the heat generated at the tool-workpiece interface in a turning process. Using a compressor disk as an illustrative example, the boundary value problem is formulated with a plate model where the perimetric edge is clamped and insulated, and the upper and lower surfaces are subjected to heat convection. The closed form solution of temperature distribution is obtained via Green's function method, based on which the thermal deflection/stresses are obtained in serial forms from the plate constitutive relations. The obtained solutions have been numerically verified with finite-element analysis (FEA), where simulations have been performed for three different materials with discrepant thermomechanical properties to study the thermal effects on the induced deflection and stresses. The analytical result is justified by its good agreement with FEA and its time efficiency in computation offers advantages in potential real-time application to manufacturing process monitoring. [ABSTRACT FROM AUTHOR]

The development of a grating interferometer with application to the angular measurement of a hard disk drive actuator arm for application to the servo-track writing process is presented. First, the theoretical background related to the linear type grating interferometer is presented, and this theory is extended to the measurement of the angular displacement of a hard disk drive actuator arm using a linear grating. A vector based diffraction technique has also been developed as a tool for visualization and analysis of the grating interferometer design. Finally, experimental setups and results from a prototype grating interferometer design are presented and discussed to demonstrate the feasibility of the grating interferometer measurement system. [DOI: 10.1115/1.1360694]

An important aspect in recycling and reuse for environmentally conscious manufacturing is disassembly. Although disassembly systems contain the same basic elements as assembly systems, the disassembly problem differs significantly from the assembly problem due to the fact that the incoming disassembly product is not controlled. In addition, complete dismantling of products is not necessarily required for disassembly, whereas assembly builds a product completely. This paper describes a model for automated disassembly that accounts for workcell interaction and used product constraints. The model provides an essential means to determine, in real-time, the next component for disassembly using the knowledge of the product design and sensor feedback minimizing the steps to remove goal components. Sets of components for removal were resolved by minimizing setup time for disassembling the component. Given the model, a controller for product disassembly is defined that can account for missing and known replacement components. The controller can recover from unknown replacement components and jammed components when alternate removal sequences exist to meet the cell goal. Two case study examples are presented and experimentally simulated. Simulation results based on real product, vision sensor measure, and process input are presented and discussed. It is expected that the concepts demonstrated through these case studies can provide useful insights into other mechanical assemblies. Index Terms--Assembly system, disassembly, product modeling, supervisory control, workcell programming.

In machine vision applications, accuracy of the image far outweighs image appearance. This paper presents physically-accurate image synthesis as a flexible, practical tool for examining a large number of hardware/software configuration combinations for a wide range of parts. Synthetic images can efficiently be used to study the effects of vision system design parameters on image accuracy, providing insight into the accuracy and efficiency of image-processing algorithms in determining part location and orientation for specific applications, as well as reducing the number of hardware prototype configurations to be built and evaluated. We present results illustrating that physically accurate, rather than photo-realistic, synthesis methods are necessary to sufficiently simulate captured image gray-scale values. The usefulness of physically-accurate synthetic images in evaluating the effect of conditions in the manufacturing environment on captured images is also investigated. The prevalent factors investigated in this study are the effects of illumination, the sensor non-linearity and the finite-size pinhole on the captured image of retroreflective vision sensing and, therefore, on camera calibration was shown; if not fully understood, these effects can introduce apparent error in calibration results. While synthetic images cannot fully compensate for the real environment, they can be efficiently used to study the effects of ambient lighting and other important parameters, such as true part and environment reflectance, on image accuracy. We conclude with an evaluation of results and recommendations for improving the accuracy of the synthesis methodology.