Richard E. Billo

Optimization of indoor wireless communication network layouts

Radio Frequency Data Communications (RFDC)technology is rapidly becoming a critical component of many traditional industrial engineering functions including materials tracking, inventory control, warehousing, order processing, shipping and database management. As a means of moving information, RFDC has many attractive features, such as speed, accuracy, reliability, convenience and low operating costs. When implementing RFDC systems a major problem is to quickly and efficiently determine the locations where transceivers should be placed so that effective radio communication can take place. The research described in this paper addresses this issue by developing a computerized layout simulation system that incorporates heuristic optimization methods to solve the placement problem. The effectiveness of this unique automated layout methodology is demonstrated by comparing it with the current method of utilizing manual site surveys, as well as with other placement methods. The methodology and solutions are validated by field-testing at actual facilities.

A neural network process model for abrasive flow machining operations

This paper describes the development of a predictive process modeling system for the abrasive flow machining (AFM) process. This process is used for polishing and surface removal of workpieces with an internal flow path. The core of the process modeling system is a set of neural network models that predicts surface finish and dimensional change. These neural network models are then paired with a heuristic search algorithm to select sets of machine setup parameters for the AFM process. The heuristic search is specifically designed to avoid allowing the neural networks to extrapolate. The completed system was validated using several test pieces, and the results were very promising. The system is currently planned for implementation into the production process. The system has the potential to significantly reduce the development time for new applications of the process and can also be used to suggest alternative machine setup parameters when certain media types are unavailable.

A cost model for the evaluation of alternative cellular manufacturing configurations

This paper describes the use of a cost model to aid a design team in selecting a configuration of parts and machines for manufacturing cells. Given a set of proposed solutions ranging from a pure job shop to a pure cellular configuration, the total cost of each solution is evaluated. This calculation includes machine investment, machine setup, and material move costs. The model is illustrated with a simple example. In addition to the cost model, other pertinent factors which are not included in the model are discussed and used to aid in the final cell configuration decision. Finally, the work is illustrated with an actual data set from a local manufacturer that recently implemented manufacturing cells.

A genetic cluster algorithm for the machine-component grouping problem

This research presents the usage of a genetic algorithm for the clustering of parts and machines. A detailed analysis is shown comparing GCA results with single link cluster analysis, rank order clustering, and the direct clustering algorithm. GCA was also compared with several additional cell formation heuristics described in the recent literature, including GRAPHICS, MODROC, and a cost-based heuristic. Results showed that the GCA was far superior over single link cluster analysis and provided equivalent results to those of the direct clustering algorithm and rank order clustering. GCA was also found to provide superior results to the other heuristics. The discussion explains these findings by illustrating the inflexibility of traditional cell formation heuristics in the selection of final machine-component groupings.

Representing group technology classification and coding techniques with object oriented modeling principles

The purpose of this paper is to show the common basis of several object-oriented design modeling principles as compared with those used in classification and coding (C&C) for group technology applications. Five types of decision tree (E-trees, N-trees, X-trees, D-trees, and C-trees) are shown to be in exact correspondence with the object-oriented modeling principles generalization with disjoint subclasses, generalization with overlapping subclasses, classification, generalization with restriction, and aggregation, respectively. In addition, C&C modeling and subsequent database implementation are shown to be enhanced through application of such object-oriented modeling principles as association and role names. Finally, a case study is presented that illustrates the application of these principles in the design and implementation of a C&C system for abrasive flow machining.

Three rapid and effective requirements definition modelling tools: evolving technology for manufacturing system investigations

Abstract Current structured analysis tools are plagued by such problems as long completion times, complex notation, high costs, and voluminous documentation. To overcome these difficulties, the authors propose three new tools for effective definition of integrated information systems for manufacturing systems: the triple diagonal, the user-concept diagram, and the concept map. The triple diagonal is used to identify and prioritize major information system modules required of the factory. The user-concept diagram plays a complementary, expansive role to the triple diagonal as it serves to model the details of the process Dow for major information system modules. The concept map is used in parallel with both of the above tools to help structure important entity/object classes making up ihc database. The tools were tested through a case study involving a startup information system design effort. This effort involved the verification of contractor software support of essential information flows within a large...

A design methodology for configuration of manufacturing cells

This paper presents a general design methodology for manufacturing cells. The approach makes use of the observation that 85% of the production demand of a manufacturing facility can be attributed to 15% of the products manufactured in the facility. This logic was extended to manufacturing cell design. Specifically, within a part family, those parts that have a high steady demand should be placed in cells that are configured and operated similar to a flow line. Those part numbers within the family that have little demand should be assigned to cells designed to operate more as a job shop. In this way, a manufacturing cell that is designed to serve both the high and low demand components will not be impeded by imposed constraints resulting from demand or processing time considerations for individual parts within the family. The author presents a ten step approach for analysis and design of such cells after initial machine-component groupings have been formed.

Accelerating the generation of work measurement standards through automatic speech recognition: A laboratory study

Automatic Speech Recognition (ASR) is an emerging technology. As often is the case with new technologies, there is little guidance available on the considerations accompanying its incorporation into industrial settings. This paper presents the steps and factors to consider for successful integration of ASR systems into industrial environments. In particular, this work shows the successful application of ASR within the context of the generation of work measurement time standards. The generation of time standards is a time consuming process that has always slowed the work measurement task and increased its costs. It is shown that by using ASR the work analyst can develop more efficient, more reliable, detailed time estimates in real time, without the need for a keyboard or paper. In laboratory experiments, time reductions of 70% were demonstrated in generating time standards for common manual labour tasks. In two field studies, positive user satisfaction was expressed in the application of ASR for generatin...

Performance standards and testing of two-dimensional bar code systems for overhead scanning

Abstract This paper describes a standard testing methodology to objectively compare the performance of a new class of two-dimensional bar code systems for an overhead sortation and tracking application in an automated material handling environment. The performance of two different two-dimensional bar code systems was compared on five different tests. These tests included (1) range of speed, (2) width of field, (3) symbol rate with undamaged, unoriented symbols, (4) symbol rate with damaged, oriented symbols, and (5) focus time. Results showed that four of the five tests appear to be valid means for comparing performance of differing two-dimensional technologies for an overhead sortation/tracking application.

TEST PROTOCOL FOR COMPARING TWO-DIMENSIONAL BAR CODE HAND-HELD READER TECHNOLOGIES

Abstract Current advances in reader technology offer users of two-dimensional bar codes many choices in selecting a hand-held reader for their particular application. Specifications exist that describe required functionality for various scanning technologies, but little work has been done in the published literature with respect to assessing the relative performances of these technologies when actually incorporated into a hand-held unit. In this paper, a suite of standard tests is presented to measure the decode time of hand-held readers. These tests were applied to a PDF417 two-dimensional bar code symbol and used to compare the performance of five newly developed hand-held readers over four different reader technologies. The technologies included laser scanning, linear CCD, area CCD, and CMOS technology. The tests focused on the following factors that typically affect decode time: lighting conditions, reading distance, orientation angles of the reader, and use of the readers in a typical freehand application. Results show the tests to be a valid means for comparing performance of differing hand-held reader technologies typically used for two-dimensional dimbologies.