Institute for Systems Research Technical Reports
Permanent URI for this collectionhttp://hdl.handle.net/1903/4376
This archive contains a collection of reports generated by the faculty and students of the Institute for Systems Research (ISR), a permanent, interdisciplinary research unit in the A. James Clark School of Engineering at the University of Maryland. ISR-based projects are conducted through partnerships with industry and government, bringing together faculty and students from multiple academic departments and colleges across the university.
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Item "Manufacturing-Operation Planning Versus AI Planning(1995) Nau, D.S.; Gupta, Sandeep K.; Regli, W.C.; ISRAlthough AI planning techniques can potentially be useful in several manufacturing domains, this potential remains largely unrealized. Many of the issues important to manufacturing engineers have not seemed interesting to AI researchers---but in order to adapt AI planning techniques to manufacturing, it is important to address these issues in a realistic and robust manner. Furthermore, by investigating these issues, AI researchers may be able to discover principles that, are relevant for AI planning in general.As an example, in this paper we describe the techniques for manufacturing-operation planning used in IMACS (Interactive Manufacturability Analysis and Critiquing System). We compare and contrast them with the techniques used in classical AI planning systems, and point out that some of the techniques used in IMACS may also be useful in other kinds of planning problems.
Item Integrating DFM with CAD through Design Critiquing(1994) Gupta, Satyandra K.; Regli, W.C.; Nau, D.S.; ISRIn research on concurrent engineering and engineering design, the increasing use of design for manufacturability(DFM) is expanding the scope of traditional design activities in order to identify and eliminate manufacturing problems during the design stage. However, manufacturing a product generally involves many different kinds of manufacturing activities, each having different characteristics. A design that is good for one kind of activity may not be good for another; for example, a design that is easy to assemble may not be easy to machine. One obstacle to DFM is the difficulty involved in building a single system that can handle the various manufacturing domains relevant to a design.In this paper, we propose an architecture for integrating CAD with DFM. This involves the use of multiple critiquing systems, each one dedicated to one type of manufacturing domain. In the proposed framework, as the designer creates a design, a number of critiquing systems analyze its manufacturability with respect to different manufacturing domains (machining, fixturing, assembly, inspection, and, so forth), and offer advice about potential ways of improving the design.
We anticipate that this approach can be used to build an environment that will allow designers to create high-quality products that can be manufactured more economically. This will reduce the need for redesign, thus reducing product cost and lead time.
Item Building MRSEV Models for CAM Applications(1993) Gupta, Satyandra K.; Kramer, Thomas R.; Nau, D.S.; Regli, W.C.; Zhang, G.M.; ISRIntegrating CAD and CAM applications, one major problems is how to interpret CAD information in a manner that makes sense for CAM. Our goal is to develop a general approach that can be used with a variety of CAD and CAM applications for the manufacture of machined parts.In particular, we present a methodology for taking a CAD model, extracting alternative interpretations of the model as collections of MRSEVs (Material Removal Shape Element Volumes, a STEP-based library of machining features), and evaluating these interpretations to determine which one is optimal. The evaluation criteria may be defined by the user, in order to select the best interpretation for the particular application at hand.
Item Generation and Evaluation of Alternative Operation(1992) Nau, D.S.; Zhang, G.M.; Gupta, Satyandra K.; ISRThis paper presents a new and systematic approach to assist decision-making in selecting machining operation sequences. The approach is to produce alternative interpretations of design as different collections of machinable features, use these interpretations to generate alternative machining operation sequences, and evaluate the cost and achievable machining accuracy of each operations sequence. Given the operation sequences and their evaluations, it is then possible to calculate the performance measures of interest, and use these performance measures to select, from among the various alternatives, one or more of them that can best balance the need for a quality product against the need for efficient machining.Item Evaluating Product Machinability for Concurrent Engineering(1992) Nau, D.S.; Zhang, G.M.; Gupta, Satyandra K.; Karinthi, Raghu R.; ISRDecisions made during the design of a machined part can significantly affect the product's cost, quality, and lead time. Thus, in order to address the goals of concurrent engineering, it is important to evaluate the machinability of the proposed design, so that the designer can change the design to improve its machinability, To determine the machinability of the part, all of the possible alternative ways to machine the part should be generated, and their machinability evaluated. This chapter describes the techniques we have developed to do this automatically.The information provided by these techniques will prove useful in two ways: (1) to provide information to the manufacturing engineer about alternative ways in which the part might be machined, and (2) to provide feedback to the designer identifying problems that may arise with the machining.