The thesis presents an approach to adaptive decision making strategies to reduce bottlenecks in a drilling operation and to extend tool life. It is an attempt to portray the real drilling system in a typical Flexible Manufacturing System (FMS) layout. The system designed serves as back end intelligence to drilling machines (INTELLIDRILL) in a Flexible Manufacturing System for making dynamic and real time decisions. INTELLIDRILL uses mathematical and adaptive tool reliability models to simulate the machining conditions and tool availability for an operation based on history of tool failures. The results are used to compute the machining parameters and the tools required for an operation. INTELLIDRILL can devise strategies for different tool materials to operate on batches of different materials. INTELLIDRILL decisions could lead to significant savings in tooling costs and reduction in flow line bottlenecks.

The thesis presents an approach to adaptive decision making strategies to reduce bottlenecks in a drilling operation and to extend tool life. It is an attempt to portray the real drilling system in a typical Flexible Manufacturing System (FMS) layout. The system designed serves as back end intelligence to drilling machines (INTELLIDRILL) in a Flexible Manufacturing System for making dynamic and real time decisions. INTELLIDRILL uses mathematical and adaptive tool reliability models to simulate the machining conditions and tool availability for an operation based on history of tool failures. The results are used to compute the machining parameters and the tools required for an operation. INTELLIDRILL can devise strategies for different tool materials to operate on batches of different materials. INTELLIDRILL decisions could lead to significant savings in tooling costs and reduction in flow line bottlenecks.

A tool path generation method for sculptured surfaces defined by triangular meshes is presented in this thesis along with an algorithm that helps determine the best type of cutter geometry to machine a specific surface. Existing tool path planning methods for sculptured surfaces defined by triangular meshes require extensive computer processing power and result in long processing times mainly since surface topology for triangular meshes is not provided. The method presented in this thesis avoids this problem by offsetting each triangular facet individually. The combination of all the individual offsets make up a cutter location surface. A single triangle offsetting results in many more triangles; many of these are redundant, increasing the time required for data handling in subsequent steps. To avoid the large number of triangles, the proposed method creates a bounding space to which the offset surface is limited. The original surface mesh describes the bounding surface of a solid, thus it is continuous with no gaps. Therefore, the resulting bounding spaces are also continuous and without gaps. Applying the boundary space limits the size of the offset surface resulting in a reduction in the number of triangular surfaces generated. The offset surface generation may result in unwanted intersecting triangles. The tool path planning strategy addresses this issue by applying hidden-surface removal algorithms. The cutter locations from the offset surface are obtained using the depth buffer. The simulation and machining results show that the tool paths generated by this process are correct. Furthermore, the time required to generate tool paths is less than the time required by other methods. The second part of this thesis presents a method for selecting an optimal cutter type. Extensive research has been carried out to determine the best cutter size for a given machining operation. However, cutter type selection has not been studied in-depth. This work presents a method for selecting the best cutter type based on the amount of material removed. By comparing the amount of material removed by two cutters at a given cutter location the best cutter can be selected. The results show that the optimal cutter is highly dependent on the surface geometry. For most complex surfaces it was found that a combination of cutters provides the best results.

Today&rsquo / s Computer Aided Software Engineering (CASE) technology covers nearly all activities in software development ranging from requirement analysis to deployment.Organizations are evaluating CASE tool solutions to automate or ease their processes. While reducing human errors, these tools also increase control, visibility and auditability of the processes. However, to achieve these benefits, the right tool or tools should be selected for usage in the intended processes. This is not an easy task when the vast number of tools in the market is considered. Failure to select the right tool may impede project&rsquo / s progress besides causing economic loss. In this thesis study, a methodology is proposed for CASE tool evaluation and selection among various candidates and the points that separate this work from similar studies in the literature are explained. Moreover, the methodology is performed on a case study.

A tool path generation method for sculptured surfaces defined by triangular meshes is presented in this thesis along with an algorithm that helps determine the best type of cutter geometry to machine a specific surface. Existing tool path planning methods for sculptured surfaces defined by triangular meshes require extensive computer processing power and result in long processing times mainly since surface topology for triangular meshes is not provided. The method presented in this thesis avoids this problem by offsetting each triangular facet individually. The combination of all the individual offsets make up a cutter location surface. A single triangle offsetting results in many more triangles; many of these are redundant, increasing the time required for data handling in subsequent steps. To avoid the large number of triangles, the proposed method creates a bounding space to which the offset surface is limited. The original surface mesh describes the bounding surface of a solid, thus it is continuous with no gaps. Therefore, the resulting bounding spaces are also continuous and without gaps. Applying the boundary space limits the size of the offset surface resulting in a reduction in the number of triangular surfaces generated. The offset surface generation may result in unwanted intersecting triangles. The tool path planning strategy addresses this issue by applying hidden-surface removal algorithms. The cutter locations from the offset surface are obtained using the depth buffer. The simulation and machining results show that the tool paths generated by this process are correct. Furthermore, the time required to generate tool paths is less than the time required by other methods. The second part of this thesis presents a method for selecting an optimal cutter type. Extensive research has been carried out to determine the best cutter size for a given machining operation. However, cutter type selection has not been studied in-depth. This work presents a method for selecting the best cutter type based on the amount of material removed. By comparing the amount of material removed by two cutters at a given cutter location the best cutter can be selected. The results show that the optimal cutter is highly dependent on the surface geometry. For most complex surfaces it was found that a combination of cutters provides the best results.

Dawson (2009) suggested a twelve step methodology for implementing knowledge management solutions following research which showed that implementing knowledge management solutions was not as successful as expected. This thesis investigates the third of this twelve step methodology which requires finding a knowledge management solution in the context of the problem. The aim of the research is to determine a methodology that will provide a systematic way for managers to select an appropriate knowledge management tool given a particular working environment. Two organisations are investigated to confirm that there is a need for a systematic methodology for selecting knowledge management tools and how a methodology may help in achieving selecting an appropriate tool. This investigation is carried out using case studies, action research and interviews and results in discovering that organisations do not have a systematic method for selecting tools which leads to tools being selected haphazardly and not always successfully. Two tools are developed to aid a manager in selecting a knowledge management tool: the House of Knowledge Management Tool Selection and the Knowledge Management Tool Classification Grid. The House tool helps to identify the knowledge problem being solved and evaluates all potential knowledge management tools against the problem. The barriers to the potential success of the tools are also examined. The grid identifies potential tools by classifying them against knowledge problems. The two tools are further refined and developed using the two organisations as case studies to demonstrate how and when the tools can be used. This leads to development of the Barrier House and the Evaluation Grid. A framework and associated methodology are then developed that can be used as a guide to using the tools, offering a systematic approach to selecting knowledge management tools given any environment and thus accomplishing the aim of the thesis.

The process of taking a solid model and producing a machined part requires the time and skillset of a range of professionals, and several hours of part review, process planning, and production. Much of this time is spent creating a methodical step-by-step process plan for creating the part from stock. The work presented here is part of a software package that performs automated process planning for a solid model. This software is capable of not only greatly decreasing the planning time for part production, but also give valuable feedback about the part to the designer, as a time and cost associated with manufacturing the part. In order to generate these parameters, we must simulate all aspects of creating the part. Presented here are models that replicate these aspects. For milling, an automatic tool selection method is presented. Given this tooling, another model uses specific information about the part to generate a tool path length. A machining simulation model calculates relevant parameters, and estimates a time for machining given the tool and tool path determined previously. This time value, along with the machining parameters, is used to estimate the wear to the tooling used in the process. Using the machining time and the tool wear a cost for the process can be determined. Other models capture the time of non-machining production times, and all times are combined with billing rates of machines and operators to present an overall cost for machining a feature on a part. If several such features are required to create the part, these models are applied to each feature, until a complete process plan has been created. Further post processing of the process plan is required. Using a list of available machines, this work considers creating the part on all machines, or any combination of these machines. Candidates for creating the part on specific machines are generated and filtered based on time and cost to keep only the best candidates. These candidates can be returned to the user, who can evaluate, and choose, one candidate. Results are presented for several example parts. / text

The focus of the present work is natural human like grasping, for realistic performance simulations in digital human modelling (DHM) environment. The performance simulation for grasping in DHM is typically done through high level commands to the digital human models (DHMs). This calls for a natural and unambiguous scheme to describe a grasp which would implicitly accommodate variations due to the hand form, object form and hand kinematics. A novel relational description scheme is developed towards this purpose. The grasp is modelled as a spatio-temporal relationship between the patches (a closed region on the surface) in the hand and the object. The task dependency of the grasp affects only the choice of the relevant patches. Thus, the present scheme of grasp description enables a human like grasp description possible. Grasping can be simulated either in an interactive command mode as discussed above or in an autonomous mode. In the autonomous mode the patches have to be computed. It is done using a psychological concept, of affordance. This scheme is employed to select a tool from a set of tools. Various types of grasps a user may adopt while grasping a spanner for manipulating a nut is simulated. Grasping of objects by human evolves through distinct naturally occurring phases, such as re-oreintation, transport and preshape. Hand is taken to the object ballpark using a novel concept of virtual object. Before contact establishment hand achieves the shape similar to the global shape of the object, called preshaping. Various hand preshape strategies are simulating using an optimization scheme. Since the focus of the present work is human like grasping, the mechanism which drives the DHMs should also be anatomically pertinent. A methodology is developed wherein the hand-object contact establishment is done based on the anatomical observation of logarithmic spiral pattern during finger flexion. The effect of slip in presence of friction has been studied for 2D and 3D object grasping endeavours and a computational generation of the slip locus is done. The in-grasp slip studies are also done which simulates the finger and object response to slip. It is desirable that the grasping performance simulations be validated for diverse hands that people have. In the absence of an available database of articulated bio-fidelic digital hands, this work develops a semi-automatic methodology for developing subject specific hand models from a single pose 3D laser scan of the subject's hand. The methodology is based on the clinical evidence that creases and joint locations on human hand are strongly correlated. The hand scan is segmented into palm, wrist and phalanges, both manually and computationally. The computational segmentation is based on the crease markings in the hand scan, which is identified by explicitly painting them using a mesh processing software by the user. Joint locations are computed on this segmented hand. A 24 dof kinematic structure is automatically embedded into the hand scan. The joint axes are computed using a novel palm plane normal concept. The computed joint axes are rectified using the convergence, and intra-finger constraints. The methodology is significantly tolerant to the noise in the scan and the pose of the hand. With the proposed methodology articulated, realistic, custom hand models can be generated. Thus, the reported work presents a geometric framework for comprehensive simulation of grasping performance in a DHM environment.