The potential of many nondestructive inspection methods and evaluation procedures are often demonstrated under rather pristine conditions. Considerable difficulty may result from attempting to apply such methodologies to actual components. This is further complicated if the material is inhomogeneous and anisotropic. Nevertheless with the use of advanced materials in complex geometry critical components, it is necessary to develop methods for assuring their quality during or upon completion of manufacture. This presentation will examine the challenges associated with this task and discuss the feasibility of the acousto-ultrasonic material characterization method for meeting these challenges. Particular attention will be given to implementing this methodology in an automated, cost effective manner. Work that is in progress involving laser in/out ultrasonic generation and detection technology, along with robotic sensor manipulation, and advanced computerized data acquisition and analysis will be discussed. / Master of Science

For about ten years, Texas Instruments has been developing a software environment of integrated tools for designing, debugging and documenting process control solutions that run on programmable controllers. The product - the Applications Productivity Tool (APT), allows process and control engineers to design and program in a graphical environment that compiles into machine code (relay ladder logic). APT is primarily targeted for the batch manufacturing industry in which engineers combine elements of both discrete and continuous control strategies. The objective of this research was to determine the applicability of APT in discrete parts manufacturing, using two applications of discrete manufacturing. One of these applications was a Fischertechnik model of a manufacturing system, configured to simulate the production of three distinct parts. The other application was the flexible manufacturing system being assembled in the Computer Integrated Manufacturing Laboratory (CIM Laboratory), which is equipped to produce models of a robot and a CNC milling machine. / Master of Science

Fuzzy control is a rule based type of control that aims to imitate the human's ability to express a control policy using linguistic rules, and to reason using those rules to control a system. Fuzzy control is nonlinear and not dependent on a precise mathematical description of the plant, and is therefore more easily applied to systems such as industrial processes that are hard to model. An overview is given of the fuzzy controller, along with descriptions of applications and theoretical approaches to designing and analyzing the controller. The self-organizing controller is able to generate or modify its rules in real time based on the system performance. It was tested to determine how well it was able to learn a quality control policy. The self-organizing controller was found to exhibit poor steady state performance, and to be equally likely to learn poor control as to learn good control. It was not found to eliminate the need for careful tuning of the controller parameters and gains. / Master of Science

An industrial vision system is a useful and often integral part of a computer integrated manufacturing system. Successful integration of vision capabilities into a manufacturing system involves extracting from image data the information which has meaning to the task at hand, and communicating that information to the larger system. The goal of this research was to integrate the activities of a stand-alone vision system into the operation of a manufacturing system; more specifically, the host controller and vision system were expected to work together to determine the status of pallets moving through the system. Pallet status was based on whether the objects on the pallet were correct in shape, location, and orientation, as compared to a pallet model generated using the microcomputer-based CADKEY CAD program. Cadd.c, a C language program developed for this research, extracts object area, perimeter, centroid, and principal angle from the CAD KE Y model for comparison to counterparts generated by the vision system. This off-line approach to supplying known parameters to the vision system was chosen over the traditional "teach by showing" method to take advantage of existing CAD data and to avoid disruption of the production system. The actual comparison of model and image data was performed by a program written in VPL, the resident language of the GE Optomation II Vision System. The comparison program relies on another short VPL program to obtain a pixel/inch ratio which equates the disparate units of the two systems. Model parameters are passed to the vision system via hardware and software links developed as part of this research. Three C language programs enable the host computer to communicate commands and parameters, and receive program results from the vision system. Preliminary testing of the system revealed that the object location and surface texture, lighting conditions, and pallet background all affected the image parameter calculations and hence the comparison process. / Master of Science

This study traces the evolution of the applied ecological discipline of range management in terms of the goals, methods, concepts, and criteria developed by range management for their science between 1897 and 1920. It argues, in contrast to the traditional view uÌ uat describes the knowledge-development process in applied science as just science applied to social problems, that wider social goals, values, concepts, and criteria play a definite role in shaping the applied science knowledge-development process. The first generation of range management allowed the primary users of the knowledge in the wider society, the stockmen in the West and Southwest, to have a direct influence on the knowledge-development process. The next generation of scientists eliminated the stockmen's direct influence on the knowledge-development process, yet the stockmen still influenced that process indirectly in various ways. This study concludes that an orientation towards the wider society that actually applies the knowledge is characteristic of range management and may be illustrative of illustrative of many applied sciences. Due to that orientation towards the wider society and to the wider society's influence on the scientist's choice of methods,concepts, and criteria, another characteristic of range management and possibly of other applied sciences is a tension in the knowledge development process between that orientation and the individual goals of scientists in their research. / Master of Science

A conceptual framework for the design and performance evaluation of flexible manufacturing cells (FMCS) based on the strategic objectives of firms was developed. Four different types of manufacturing task profiles were identified based on the primary manufacturing task, product characteristics, and manufacturing system characteristics of a strategic business unit (SBU). Performance measures were discussed for each of the manufacturing task profiles, and the task profiles of firms likely to implement FMCs were identified. A methodology, based on the analytic hierarchy process (AHP), introduced by Saaty, was developed to prioritize the manufacturing objectives of an FMC. The implications of each of the manufacturing objectives for an FMC were hypothesized and related performance measures identified. An interactivecomputer-based model, based on the theory of closed network-of–queues, was then developed to aid in the preliminary design and evaluation on an FMC. Field work was carried out to determine the practical applicability of the conceptual framework. Visits to a company in the Southeastern United States were made and an analysis of the FMC being developed in the Department of Industrial Engineering and Operations Research, at Virginia Tech was conducted. The framework developed in this research was used to determine the manufacturing task profile of the company, identify key performance measures, and exercise the AHP methodology for one cell. Operational measures were then calculated for the FMC, using the computer-based model. / Master of Science

Variable Geometry Trusses (VGT’s) can be used as the fundamental building blocks in constructing long-chain, high degree-of-freedom manipulators. This thesis focuses on the kinematics of two such manipulators. It also illustrates how the concept of shape control can be applied to simplify the computational aspects of controlling these devices. To serve as examples, algorithms are developed for the control of both a thirty degree of freedom planar manipulator and a sixty degree-of-freedom spatial manipulator. Based on a review of the literature, this work appears to be the first attempt to develop real-time, position control strategies for such highly-dexterous manipulators. / Master of Science / incomplete_metadata

A method of modifying a uÌ ber optic fused biconical tapered coupler to produce a relatively temperature insensitive Michelson interferometer is presented. The modification was accomplished by cleaving the coupler after the minimum taper region and polishing, perpendicular to the endface, to a point just short of the interaction region. This allows one of the two fiber cores, which are within micrometers of each other with their claddings fused together, to be coated at its endface with a reflecting material. This reflecting core serves as the reference arm, while the other core serves as the sensing arm. Variations in the method of fabrication of the sensor are described. Because of the close proximity and short length of the reference and sensing arms, the interferometer is temperature insensitive. The miniaturized Michelson interferometer is characterized and its limitations are discussed. A surface acoustic wave detection scheme is successfully demonstrated. Results of a magnetic field sensor using the miniaturized Michelson interferometer and a magnetostrictive material are presented. / Master of Science

Computer aided diagramming (CAD) tools today are based on the approach of a fixed symbol into which text is fitted. This approach leads to shortfalls in human interfacing and tool development. The inverse view of entering the text and then drawing the symbol around it provides the basis for an innovative approach that is more natural and user friendly. This report documents benefits realized from the new approach in the development of a CAD tool referred to as DiagramEdit. / Master of Science / incomplete_metadata

A method was developed for estimating costs of harvesting operations in the hardwood stands of the Appalachian region of southwestern Virginia. The method was then tested on one logging operation to estimate the cost of harvesting a group selection tract as compared to a clearcut. Eight loggers were contacted and interviewed to obtain data on their costs of logging. The mean, median, and standard deviation of the responses were calculated to develop a profile. Mean crew size was three men, including the owner operator. Mechanized equipment consisted of a cable skidder from 75 to 120 hp. and a small to medium size loader. Average skidder age was 4.8 years. Loggers produced 144 cords per week, of which 54.6% was pulpwood and 42.4% sawtimber with 3% firewood. Products were hauled an average of 33 miles one way. Labor costs, including wages and all benefits averaged $411 per man per week. Total harvesting costs had a mean of $2252 per week. Mean hauling cost was $1289 per week. Annual production averaged 6778 cords. Cords per man hour was 0.99. Total cost per cord including hauling averaged $26. The information taken from the interviews was incorporated along with data from current literature into the Harvesting Analysis Technique (HAT), a main frame harvesting simulator, to model group selection harvests against clearcut harvests. A twenty-seven acre group selection cut was compared to a 160-acre clearcut. Clearcut area was based on the access estimated possible by the group selection skid road network. Results showed group selection harvested at a 21% slower rate than clearcutting. Harvest cost per cord was 25.8% greater. Variation in cost was caused mainly by the increased average skid distances present in the groups. Every 100 foot increase in skid distance resulted in a $0.68 increase in cost per cord for skidding in group selection harvests compared to a $0.33 increase for clearcutting. / Master of Science