Mechanical Engineering Commons^™

A Robot Vision System For Determining 3-D Coordinates Of Object Points, Tea-Quin Kim

Theses

A stereo disparity algorithm is implemented on an industrial robot vision system. One camera manipulated by an industrial robot is used to obtain stereo images of an object. After a pair of stereo images are processed, the points of interest are selected from each image. The similarities of three types of feature characters are used to assign initial weights of the, matching probabilities to a set of point candidates. Then a relaxation method, which is based on probabilities of local connectivity, similarity of feature characters, and smoothness of matching, is used iteratively to improve the initial probabilities of image matching. …

Investigation Of Surface Formation In Abrasive Waterjet Cutting, Shy-Shyan Chen

Theses

This study is concerned with experimental and numerical investigation of the dynamics of surface generation during the impingement of the abrasive waterjet on a workpiece.

A series of erosion zones were generated by the abrasive waterjet on the polished surface of stainless steel samples. The impingement was carried out at different traverse speeds and abrasive flow rates. An optical, a scanning electron microscope and a laser displacement sensor were used to investigate the developed surface.

The microscopical examination of the surface enabled determination of the shape of asperities created by individual particles, distribution of asperities on the surface and the …

An Interactive Graphics Capability For Numerical Design Optimization, Abbay P. Joshi

Theses

Hierarchical Object Oriented Program Software [HOOPS] is used here to develop an interactive graphical interface for the design optimization program CADOP5. A preprocessor provides the user with button menu options. Using various buttons like Variable Button, Obj Button, Parameter Button, etc. the user can interactively define problem variables, parameters and limits as well as interactively modify the behavior and the constraint functions. The post processor displays variable values for three consecutive design cycle in the form of bar charts. Objective function values are plotted against the number of design cycle. Using this information the user can determine if the solution …

Investigation Of The Distribution Of Particles In An Abrasive Water Jet, Sun Kim

Theses

This study is concerned with the distribution of abrasive particles within an abrasive waterJet. The Jet is generated by the Ingersoll Rand nozzle set at the different diameters of the sapphire nozzles and carbide mixers. Water pressure is maintained at 4.7- 4.9 ksi.

The distribution of particles is examined by the separation of the central and adjacent part of the flow and the measurement of the fractions of the mixture and abrasive in the separated region. The separation is carried out by diamond washers coaxial with a carbide mixer. The second series of experiments involve the estimation of the Jet …

The Rate Of Vibrational Segregation In Particulate Materials, Yidan Lan

Theses

The rate of vibratory size segregation has been modeled in multi-component size systems as a process of mutual sorting between each size species. The concept of mutual sorting is introduced from which generalized expressions are derived for the rates of change of the local concentration of each size species. In a binary system, the expressions simplify to give the expected result that the segregation rates for the large and small particles are equal but of opposite sign. Also, in these systems, the segregation rate is described by measuring the rising speed of the interface between the small and large particles. …

Design Of A Gear Driven Anti-Twister Mechanism For A Seal-Less Blood Processor, Ajit Nachiket Dastane

Theses

This thesis presents the design of a gear driven anti- twister mechanism for a blood cell separator. The anti- twister mechanism allows for continuous feed and discharge lines that are rigidly attached to the rotating centrifuge head, thus eliminating the need of rotating seals. It is anticipated that the device using a gear driven anti-twister mechanism will have smoother power transmission and closer rpm tolerances.

In addition, a procedure for the dynamic analysis of the existing device, which uses a belt-driven anti-twister mechanism, is developed. The experimental values obtained from the device are compared with the theoretical values obtained by …

Ionitriding To Improve The Wear Resistance Of Ferrous Materials, Ravi K. Kodali

Theses

In this work the effect of ionitriding treatment on wear resistance of ferrous materials was studied. A basic understanding of the ionitriding concepts were given and the advantages of this process over other conventional nitriding treatments were outlined. The effect of various parameters like gas composition, temperature, pressure, process duration and power density on the metallurgical aspects of this process were discussed. Under technical aspects of this technology, advantages of pulsed direct current over conventional direct current nitriding systems were given. In this work wear tests were performed on components made from gray cast iron, alloy steel (AISI 4340), and …

Artificial Intelligence And Mechanical Engineering, Efthimios Papayianis

Theses

Many artificial intelligence programs have been developed to assist engineers in their search for solutions. Most of them are designed to assist with a specific type of problem and they usually take the form of an expert system. However one may also use the concepts of artificial intelligence to solve a problem for which an expert system is not yet available.

Three expert systems were developed with Prolog to demonstrate how artificial intelligence can help solve problems in mechanical engineering. The first expert assists in the design of simply supported beams. The second expert assists in the design of thick …

An Automated System For Optimal Synthesis Of Planar Linkages, Daming Wang

Theses

This thesis addresses the fundamental weakness of the current CAD capabilities and develops a new CAD system with optimization capability. A computer-aided mechanism design system is developed for general problems of optimal kinematic synthesis of planar four-bar mechanisms. The new system is made as user-friendly as possible and it is unique in that it combines Graphics capability, general Analysis capabilities, and Optimization capability into one system. Related background theory in IMP, optimization and optimal synthesis of mechanisms are discussed. The problems and methods in developing the new system are addressed. New routines and modifications made to the original systems are …

Effects Of Compliance And Machining Prameters On Robotic Grinding/Deburring, Kung-Le Chang

Theses

A theoretical model for robotic grinding/deburring has been developed and compared with experimental results. Various grinding parameters such as depth of cut, feed rate, surface profile and roughness, grinding forces, and robot stiffness, have been experimentally investigated in this study. It was observed that the depth of cut is a function of specific grinding energy, force, and robot compliance. The observed roughness and waviness are directly proportional to depth of cut and feed rate and, in addition, to the robot compliance and the encoder quantization error. Other effects of the robot system for grinding performance are also addressed.

Hydrodynamic Lubrication Performance Of Mineral Oils With Polymer Additives, Moshe David Felzenstein

Theses

This study was undertaken with the view to determining experimentally the influence of polymer additives on journal bearing performance under static load. Viscoelastic lubricants such as oils with polymer additives are in common use and exhibit a reduced dependence of the viscosity on temperature but the effect on the performance of a static journal bearing is not clear. Additives of the polymer polyisobutylene and STP were blended with Newtonian base oil which was used to establish the baseline performance of the test bearing. A comparison was made between the performance of these blends and the base oil. The performance of …

Finite Element Method In Turbo Pascal, Tingwang Kuo

Theses

A finite element program FEM2D in FORTRAN language by J.N. Reddy has been translated into TURBO PASCAL and several features such as interactive input, mesh generation for a rectangular plate with a circular hole at the center of the plate and graphical display of the meshes and node numbers have been implemented. Four examples including potential flow and plane stress problems have been tested successfully. It is concluded that the PASCAL language on a microcomputer can he used to write a finite element program and is easier to give graphical display than FORTRAN language. The maximal number of nodes that …

Seizure And Wear Testing Methodology, I-Tsung Shih

Theses

In this work the seizure as an adhesive wear has been discussed and analyzed The diffusion hypotheses is accepted as the seizure mechanism. It was determined that the surface of machine components, material properties, and contact stresses in sliding and loading zone are responsible for the wear.

A computer controlled wear testing methodology has been developed and a wear testing machine has been designed and assembled. The tests for the selected gray cast non and alloy steel specimens with different surface treatment were performed on the designed wear testing machine.

The test results showed that the selected materials with additional …

Investigation Of Forces In The Course Of The Water Jet--Work Piece Interaction, Hung-Yuan Li

Theses

This study is concerned with the dynamic of the interaction between the water jet and the work-piece. The piezoelectric transducer was used to construct an experimental setup. The simultaneous use of the constructed setup and strain gage enables us to validate the experimental procedure. The forces in the impingment zone were measured at different operational conditions. Totally about 400 different combinations of these conditions were tested. It was found that the force is mainly determined by the diameter of the sapphire. The effects of the abrasive size , abrasive flow rate, the diameter of the carbide tube, and the stand-off …

Investigation Of A Technology For Glass Shaping By The Use Of Abrasive Waterjet, Wu-Tzung Lee

Theses

This study investigates the effects of AWJ properties on the results of glass machining and examines the feasibility of contour glass cutting. The principal defects of AWJ glass cutting are identified. A practical technique to prevent defects and to improve the quality of the glass surface is presented. A computer package was developed to provide a computer-aided programming function, a control program transformation fuction, and a object image operation function. Throughout the programming function, robot control programs can be generated to improve cutting quality and cutting speed. The transformation function can be used to change the programming modes or the …

Computer Aided Synthesis Of A Four-Bar Linkage To Generate A Symmetrical Coupler Curve, Shailendra R. Pachalag

Theses

The purpose of this study is to develop a new analytical technique for the synthesis of four-bar mechanisms to generate symmetrical curves with a coupler point passing through 8 points. The geometric expressions involved in kinematic synthesis often tend to offer difficulties such as negative radicals, alternative choices and repetitions. Here a solution procedure has been developed which avoids these difficulties. This solution procedure includes a development of a computer algorithm that should synthesize a crank-rocker type linkage for any given input crank length. This algorithm dismisses all solutions involving negative radicals and lists magnitudes of members so that those …

Design And Construction Of A Thermoelectric Calorimeter To Measure Thermal Resistance Of Building Components, Ravindra Samtaney

Theses

The steady-state thermal resistance of a building wall is an important parameter in determining its thermal performance. In-situ measurement of thermal resistance is the only unambiguous way of determining thermal resistance since the actual value may significantly differ from the laboratory or the calculated R-value.

Hitherto, the in-situ measurement of thermal resistance has been largely confined to the winter season. A thermoelectric calorimeter was designed, constructed and tested in order to provide measurements of thermal resistance during the summer as well as the winter season.

This thermoelectric calorimeter is a rectangular box, insulated on five sides and covered with an …

Integration Of Cad/Cam System Into A Waterjet Cutting Cell, Sanjay C. Shah

Theses

The work is intended to bridge the gap between CAD and CAM fora waterjet cutting cell. The output of CAD is used by CAM directly through the software interface developed. To achieve this, a postprocessor is designed for a two-dimensional system for the series 8200 Allen Bradley's 5-axes Robot Controller. Calma's DDM & DIMENSION III interactive graphics system implemented on VAX was used for the part design. The postprocessor is a computer program, written in the structured FORTRAN, that is unique for a given machine-tool/controller combination. The conversion of the coding and recording format of the APT file to the …

Investigation Of High Shear-Rate Viscoelastic Flow, Sudarshan S. Sood

Theses

The object of this study is to understand two important characteristics exhibited by viscoelastic fluids at high shear-rates, and analyse their influence on practical applications Viscoelastic fluids, such as polymer solutions, when subjected to high shear stress, behave in a manner which has not been sufficiently analytically explained In experimental studies, such fluids have shown.

(a) Stress relaxation.

(b) Decrease of viscosity with an increase in shear rate.

(c) Slight decrease of viscosity with temperature.

(d) Normal stress differences in shear flow.

In this thesis an analytical explanation is given for two (a and b ) of these features This …

Automatic Generation Of Robot Paths For Waterjet Cutting From Autocad Drawings, Samir Vij

Theses

The automatic generation of robot paths for a commercial water-jet cutting system by establishing a link with a commercial CAD system, in an attempt to achieve paper-less manufacturing and to minimize human interface is the objective of this thesis.

Water-jet cutting is an emerging technology with unlimited potential for a wide variety of manufacturing applications. Water-jet cutting systems integrated with robotic work cells allow the user to cut a variety of parts through part programs generated for robot controllers. The system employed is an Ingersoll-Rand water-jet cutting system, the movement of which is controlled by an Allen-Bradley 8200R programmable robot …

Investigation Of The Characteristics Of The Kerf And The Surface Generated In The Course Of Cutting Titanium With Abrasive Waterjets, Ajay Vora

Theses

The effect of cutting parameters on the quality of cut in the course of cutting Titanium (Gr.2) with Abrasive Waterjet is investigated. The cutting parameters include nozzle traverse rate, size and feed rate of abrasives and nozzle(s) diameter. The width of kerf (top and bottom ), taper and roughness is studied. The measurements are tabulated and plots are made to study the trend and relationship for each set of parameters.

The qualitative conclusions are made successfully but no quantitative relationship was derived. Suggestions are made for the evaluation of technology for feasibility and economic justification, and to achieve desired cutting …

Comparison Of Various Techniques For The Detection Of Lines In 2-Dimensional Images, Somayajulu Bhamidipati

Theses

The detection of straight lines in 2-dimensional images leading to polygonal approximation to the boundaries of the objects is one of the important stages in scene analysis as it leads to the description of the images. The comparison of three diverse approaches for this problem in terms of the efficiency and accuracy is made, and their performance for different types of data and different sets of parameters is studied in this thesis.

The data points are generated using either an edge detection algorithm using chain encoding on real images or a synthetic data generator, which can create a variety of …

Two Domain Heat Transfer Studies Using A Coupled Finite-Difference And Boundary Element Programs, Serap Dikmenli

Theses

An iterative coupling of a finite-difference boundary layer code "STAN5"' and a boundary element code "BEASY"2 have been used to study two dimensional convective-conductive problems. The coupling method essentially leaves undisturbed the codes of these programs and uses their custom features in their applicable domains. The boundary layer program is used-in the convective domain, while "BEASY" is used in the solid domain. Compatability conditions are established between these domain solutions and an iterative scheme is used until these conditions are mutually satisfied.

The indirect communication of compatability (boundary) criteria between these programs was achieved by two editor/data-transferor like programs. Combined …

Role Of Contact Stresses In Surface Fatigue And Wear, Chih-Chi Huang

Theses

This thesis is devoted to the role and analysis of stress distribution at the area of load and slide contact in the surface fatigue. The orthogonal shear stresses are critical stresses for surface fatigue in pure rolling contact. On sliding combination with rolling, the maximum shear stresses become to be the prime cause for surface fatigue because they move from subsurface toward the surface. The compressive residual stress induced during manufacturing could increase the resistance to surface fatigue. Sliding speed rarely affects the stress distribution and surface fatigue. From investigation of the stick-slip region in the contact area, sliding wear …

Comparative Energy Analysis Of An Office Building Using A Microcomputeromparative Energy Analysis Of An Office Building Using A Microcomputer, Dale Krasnoff Bromberg

Theses

An energy analysis was performed on an office building using two different software packages - ASEAM and Trakload. The structure studied was the P.S.E. & G. headquarters in Newark, N.J.. The results of various parametric runs were compared. Then results from one of the programs were compared with results of a study carried out by Tishman Research Corporation and Jaros, Baum & Bolles, consulting engineers.

Although the two software products had variations in input requirements, overall the results of the two programs were similar. The overall deviation for total energy consumption between the two programs was between 3% and 15%. …

An Analysis Of The Dense Packing Of Disks : A Computer Simulated Approach, Jir-Yih Tsaur

Theses

This thesis is concerned with the analysis of dense packing of hard disks. The Voronoi diagram and the geometric neighbours were first computed. The average number of geometric neighbours of a disk is six. It is thus more efficient to choose structural neighbours from among the geometric neighbours than from among all other disks.

Through the Monte Carlo simulation by Rosato et. al., disk configurations after pouring and subsequent shaking were provided for analysis. The mean number of geometric neighbours and the average coordination number were computed. The angular distribution of the structural neighbours was discussed. The packing fraction increases …

Engraving By Cnc Milling Machine, Ram Tatiparti Reddy

Theses

A detailed study of NC, CNC and Engraving is presented. Engraving of letters of different sizes is done using the present technology in a CNC milling machine. This thesis also contains the design of a communication interface between Mark Century One Plus controller and different peripherals. Software for Engraving and Communication between the controller and a PC is developed. The generated NC code from software is simulated on the controller and the product is cut.

Closed Loop Machining In Precise Turning, Ching-Song Wei

Theses

Closed loop machining (CLM) is one of the most reliable ways to automate tool setting, part positioning and measurement on CNC machine tool. It not only can assure the quality of the product but also can improve the productivity of the machine. This paper describes the CLM from basic turning concept to application of CLM, including the feature of Mark Century 2000T and the programming methods in precise turning.

The hardware and software requirements for CLM system were presented. The algorithm for CLM programs was developed completely with a series of flow charts. Then, on the base of two projects, …

Calculation Of Heat Transfer At The Center Of A Round Plate, In Forced Convection Stagnation Flow, Ali Rohafza

Theses

The theoretical study presented here examines heat transfer at the center of a round plate, in forced convection stagnation flow.

Note that in the region of stagnation point, the flow is always laminar.

Important results presented include the variations of the similarity function f and its derivative f’ with the vertical coordinate; these results were found by using the power series method to solve the governing non-linear differential equation. In order to do that , certain things were assumed like, for example, as the point at which two solutions were spliced, η₀ =2.0, or assuming the solution at η …

Development Of A Low Cost Pc Based Robot Vision System, Raghunandan Jadhav

Theses

There has been a continued. interest in utilizing machine vision systems for robot guidance applications. Commercial vision systems can be programmed to give information about the parts in the robot work area and this information can be used by the robot computer to guide the robot. In most applications, however, the vision information cannot be easily integrated with the robot control language. This thesis considers implementation of part identification routines directly into a robot guidance language. This makes all the complicated machine vision algorithms transparent to the user and allows him to treat higher level vision functions as an extension …