Thermal Robotic Arm Controlled Spraying via Robotic Arm and Vision System

The Tribology Surface Engineering industry is a worldwide multi billion euro industry with significant health and safety risks. The thermal spraying sector of this industry employs the technique of applying molten surface coating material to a substrate via a thermal spray process which is implemented either by manual spraying or pre-programmed robotic systems. The development of autonomous robotic systems for thermal spraying surface coating would significantly improve production and profitability over pre-programmed systems and improve health and safety over manual spraying. The aim of this research was to investigate and develop through software simulation, physical modelling and testing the development of robotic subsystems that are required to provide autonomous robotic control for the thermal spraying process. Computer based modelling programs were developed to investigate the control strategy identified for the thermal spaying process. The algorithms included fifth order polynomial trajectories and the complete dynamic model where gravitational, inertia, centrifugal and coriolis torques are considered. Tests provide detail of the load torques that must be driven by the robot electric actuator for various structural changes to the thermal spraying robot and for variations in trajectory boundary conditions during thermal spraying. The non-linear and coupled forward and inverse kinematic equations of a five axis articulated robot with continuous rotation joints were developed and tested via computer based modelling and miniature physical robot modelling. Both the computer based modelling and physical model confirmed the closed form kinematic solutions. A solution to running cables through the continuous rotation joints for power and data is present which uses polytetrafloraethylene (PTFE) electroless nickel. This material was identified during the literature review of surface coating materials. It has excellent wear, friction and conductivity properties. Physical tests on a slip ring and brushes test rig using electroless nickel are presented which confirm the viability of using PTFE electroless nickel as a slip ring. Measurement of the substrate during thermal spraying so as to autonomously control the thermal spaying robot is a significant challenge. This research presents solutions for the measurement of the substrate using a low cost camera system and lasers in a single wavelength environment. Tests were carried out which resulted in the removal of a butane flame obscuring a test piece requiring measurement from the camera image so that substrate measurements can be made using image processing and analysis techniques such as canny edge detection and centroid measurements. Test results for the low cost vision system provide depth measure errors of ±0.6 % and structural measurements such as area and perimeter in the range -5% to -7.5%. These results confirm the efficacy of this novel flame removal technique

Nonterrestrial utilization of materials: Automated space manufacturing facility

Four areas related to the nonterrestrial use of materials are included: (1) material resources needed for feedstock in an orbital manufacturing facility, (2) required initial components of a nonterrestrial manufacturing facility, (3) growth and productive capability of such a facility, and (4) automation and robotics requirements of the facility

Missoula VoTech Course Catalog, 1990-1991

Course catalog for Missoula VoTech (now Missoula College).https://scholarworks.umt.edu/votechcoursecatalogs/1015/thumbnail.jp

Index to NASA Tech Briefs, 1975

This index contains abstracts and four indexes--subject, personal author, originating Center, and Tech Brief number--for 1975 Tech Briefs

Intelligent laser cladding control system design and construction.

Imperial Users onl

Machine Learning for Camera-Based Monitoring of Laser Welding Processes

Der zunehmende Einsatz automatisierter Laserschweißprozesse stellt hohe Anforderungen an die Prozessüberwachung. Ziel ist es, eine hohe Fügequalität und eine frühestmögliche Fehlererkennung zu gewährleisten. Durch die Verwendung von Methoden des maschinellen Lernens können kostengünstigere und im Optimalfall bereits vorhandene Sensoren zur Überwachung des gesamten Prozesses eingesetzt werden. In dieser Arbeit werden Methoden aufgezeigt, die mit einer an der Fokussieroptik koaxial zum Laserstrahl integrierten Kamera eine Prozessüberwachung vor, während und nach dem Schweißprozess vornehmen. Zur Veranschaulichung der Methoden wird der Kontaktierungsprozess von Kupferdrähten zur Herstellung von Formspulenwicklungen verwendet. Die vorherige Prozessüberwachung umfasst eine durch ein faltendes neuronales Netz optimierte Bauteillagedetektion. Durch ei ne Formprüfung der detektierten Fügekomponenten können zudem vorverarbeitende Schritte überwacht und die Schweißung fehlerhafter Bauteile vermieden werden. Die prozessbegleitende Überwachung konzentriert sich auf die Erkennung von Spritzern, da diese als Indikator für einen instabilen Prozess dienen. Algorithmen des maschinellen Lernens führen eine semantische Segmentierung durch, die eine klare Unterscheidung zwischen Rauch, Prozesslicht und Materialauswurf ermöglicht. Die Qualitätsbewertung nach dem Prozess beinhaltet die Extraktion von Informationen über Größe und Form der Anbindungsfläche aus dem Kamerabild. Zudem wird ein Verfahren vorgeschlagen, welches anhand eines Kamerabildes mit Methoden des maschinellen Lernens die Höhendaten berechnet. Anhand der Höhenkarte wird eine regelbasierte Qualitätsbewertung der Schweißnähte durchgeführt. Bei allen Algorithmen wird die Integrierbarkeit in industrielle Prozesse berücksichtigt. Hierzu zählen unter anderem eine geringe Datengrundlage, eine begrenzte Inferenzhardware aus der industriellen Fertigung und die Akzeptanz beim Anwender

Visualisation study of metal transfer in gas metal arc welding (GMAW)

This Abstract briefly describes a thesis on the development of techniques for the purpose of viewing Gas Metal Arc Welding (GMAW) metal transfer. The thesis also describes an elaborate investigation into the physics associated with metal transfer of this welding process. An understanding of the physical process that is GMAW metal transfer has yet to be fully realised. Many factors are thought to contribute to this phenomenon and a number of theories have been proposed and counter proposed by a multitude of welding researchers. Thus, the thesis is an attempt to better comprehend the process to hopefully lead the way to a complete understanding. The thesis firstly looks into what a weld actually is and presents the associated problems and terminology of welding so the reader may grasp the complex considerations that must be taken into account in order to produce a sound weld. A sound weld is obviously one that exhibits the properties that a designer expects from it during its applied life time. It then moves on to describe the components and materials utilised in such a welding plant. Once these welding fundamentals are shown to provide an understanding of the process, the actual metal transfer is investigated. The metal transfer types are shown together with the forces thought to play an important part in metal removal and transportation to the weld. Various parameters which are known to alter the metal transfer are also presented and discussed. From this one receives a good overall view on what changes metal transfer and also the consequences of the changes. As the title of the thesis suggests, visualisation of the electrode as it melts and travels across the welding arc is a major aim of this work. Visualisation techniques for viewing this are sought and discussed. The necessity of implementing such techniques are pointed out as well. These visualisation methods are then employed in our study. The equipment chosen and used is described in detail and the corresponding results presented. An analysis of GMAW metal transfer theories is undertaken to try and predict what is seen in the pictures produced with the visualisation methods. A comprehensive mathematical analysis is given utilising the \u27Static Force Balance Theory\u27 and the \u27Mathematica\u27 computing package. The theory is also modified to allow for tapering of the wire electrode. The results are discussed to test the validity of the theory. A discussion on possible improvements and direction for further research is also undertaken. This work is generously funded by the Co-operative Research Centre (CRC) for Materials and Joining as a component of Project 93.12. Project 93.12 is a collaborative research venture in the area of Welding Automation between the Universities of Wollongong and Sydney and the Sydney based CSIRO Division of Applied Physics. Please note that the electrical data acquired and presented in this thesis was obtained from the welding test bed facility at the University of Wollongong whose development is attributed to Professor Michael West and Mr. Lawrence Sanders

An analysis of computer aided instruction for cognitive-psychomotor development

The problem of this study was to evaluate the relationship between cognition and psychomotor development in a computer based arc welding simulation. A prettest-posttest control group design with two treatment groups and one control was used in the investigation. Forty-five Iowa State University students were selected as subjects and placed into the groups. Data collected from all participants were as follows: (1) demographic information; (2) eye-hand coordination; (3) cognitive pretest and posttest scores. The two treatment groups also provided weld quality scores. Initial training and pretesting was given to all groups in the study. The first treatment group used a microcomputer based arc welder simulation to develop welding motor skills. The second treatment group used an actual arc welder for the skill development. After a demonstration and a period of practice, the two treatment groups were instructed to complete a weld on steel plates. The welds were subsequently judged and scores recorded. Following the welding activity, all three groups received the posttest;The data collected in the study were analyzed and the findings are as follows: (1) A partial correlation showed a relationship between cognitive test performance and psychomotor skill development; (2) an analysis of variance procedure showed no difference between the welding performances of the two treatment groups while, in the weld score multiple regression equation, only posttest score and sex were shown to be valuable predictors of weld score; (3) an analysis of variance showed no difference between means of cognitive test scores of the treatment groups