High temperature tensile testing of ceramic composites

The various components of a high temperature tensile testing system are evaluated. The objective is the high temperature tensile testing of SiC fiber reinforced reaction bonded Si3N4 specimens at test temperatures up to 1650 C (3000 F). Testing is to be conducted in inert gases and air. Gripping fixtures, specimen configurations, furnaces, optical strain measuring systems, and temperature measurement techniques are reviewed. Advantages and disadvantages of the various techniques are also noted

SOME FORENSIC ASPECTS OF BALLISTIC IMAGING

Analysis of ballistics evidence (spent cartridge casings and bullets) has been a staple of forensic criminal investigation for almost a century. Computer-assisted databases of images of ballistics evidence have been used since the mid-1980s to help search for potential matches between pieces of evidence. In this article, we draw on the 2008 National Research Council Report Ballistic Imaging to assess the state of ballistic imaging technology. In particular, we discuss the feasibility of creating a national reference ballistic imaging database (RBID) from test-fires of all newly manufactured or imported firearms. A national RBID might aid in using crime scene ballistic evidence to generate investigative leads to a crime gun’s point of sale. We conclude that a national RBID is not feasible at this time, primarily because existing imaging methodologies have insufficient discriminatory power. We also examine the emerging technology of micro- stamping for forensic identification purposes: etching a known identifier on firearm or ammunition parts so that they can be directly read and recovered from crime scene evidence. Microstamping could provide a stronger basis for identification based on ballistic evidence than the status quo, but substantial further research is needed to thoroughly assess its practical viability

Hissin nappikonstruktion suunnittelu lisääville valmistusmenetelmille

Additive manufacturing, with its recent technological developments, has increasingly disrupted how products are designed and manufactured. Within additive manufacturing, there has been a shift from the production of visual models and rapid prototyping applications to direct digital manufacturing of end products. Additive manufacturing provides intriguing possibilities in the design of new and existing products. These radical, pioneering designs have already redefined whole industries. This thesis provides a practical case study for an additive manufacturing redesign together with a literature review of the current additive manufacturing technologies and applications. The target of the redesign was a low volume elevator button assembly. Concepts were prototyped and tested in contrast to the current industry specification. As a result of the thesis, a functional button assembly was produced and tested. The part count, material usage, and costs were reduced compared to the original. However, all industry requirements were not met. A need for a more systematic material and process selection was identified. Nevertheless, additive manufacturing was proven to be a serious alternative in the production of low volume plastic products and should be researched further.Lisäävien valmistusmenetelmien teknologinen kehitys vaikuttaa enenevissä määrin siihen, miten fyysisiä tuotteita valmistetaan. Visuaalisten- sekä pikamallien tulostuksesta ollaan siirtymässä lopputuotteiden suoraan valmistukseen. Geometristen rajoitusten vähyys luo kiinnostavia mahdollisuuksia uusien ja olemassa olevien tuotteiden suunnittelussa. Uudet radikaalit ja uraauurtavat tuotteet ovat jo määrittäneet uudelleen kokonaisia toimialoja. Tämän diplomityön käytännön osuudessa suunnittellaan hissin nappikonstruktio täysin uusiksi lisäävien valmistusmenetelmien näkökulmasta. Työ tarjoaa myös kirjallisen läpileikkauksen lisääviin valmistusteknologioihin sekä käyttökohteisiin. Käytännön työssä etsittiin lisäävien valmistusmenetelmien etuja hyödyntäviä konsepteja, prototypoitiin, sekä testattiin kehiteltyjä ratkaisuja suhteessa toimialan vaatimuksiin. Työn tuloksena valmistettiin ja testattiin toiminnallinen nappikonstruktio. Kokoonpanon osamäärää, materiaalinkäyttöä sekä hintaa saatiin vähennettyä suhteessa alkuperäiseen. Kaikkia vaatimuksia ei kuitenkaan saatu täytettyä. Prosessin aikana tunnistettiin tarve systemaattisemmalle materiaali- sekä valmistusprosessivalinnalle. Tästä huolimatta lisäävät valmistusmenetelmät todettiin vakavasti otettavaksi vaihtoehdoksi matalan volyymin muovituotteiden valmistuksessa

From a Competition for Self-Driving Miniature Cars to a Standardized Experimental Platform: Concept, Models, Architecture, and Evaluation

Context: Competitions for self-driving cars facilitated the development and research in the domain of autonomous vehicles towards potential solutions for the future mobility. Objective: Miniature vehicles can bridge the gap between simulation-based evaluations of algorithms relying on simplified models, and those time-consuming vehicle tests on real-scale proving grounds. Method: This article combines findings from a systematic literature review, an in-depth analysis of results and technical concepts from contestants in a competition for self-driving miniature cars, and experiences of participating in the 2013 competition for self-driving cars. Results: A simulation-based development platform for real-scale vehicles has been adapted to support the development of a self-driving miniature car. Furthermore, a standardized platform was designed and realized to enable research and experiments in the context of future mobility solutions. Conclusion: A clear separation between algorithm conceptualization and validation in a model-based simulation environment enabled efficient and riskless experiments and validation. The design of a reusable, low-cost, and energy-efficient hardware architecture utilizing a standardized software/hardware interface enables experiments, which would otherwise require resources like a large real-scale test track.Comment: 17 pages, 19 figues, 2 table

Redução do custo de manutenção e aumento da eficiência na secção de estampagem a quente

This work was developed as part of a curricular internship at Gestamp Aveiro, to reduce maintenance costs associated to the hot stamping production line. For the development of this report, an in-depth study of the entire production line was carried out (from the entry of raw material in the process to the exit of the final part), to identify the possible existing problems. These problems were related to early wear or repetitive equipment failures. The causes and consequences of these failures were investigated. The impact of each of the problems was studied to access which of those were to be worked on. The selected criteria were the percentage of the maintenance budget each represented. Research to implement new solutions and improvements carried out by the company were also analysed. The areas identified as most relevant were the wear of ceramic rollers in the kiln/furnace and its implications, the excessive wear of the blank referencing presses and the excessive contamination of the shop floor by metallic dust from the laser cutting process, with special impact on the laser tool head’s components. Then, a research was conducted to discover and propose improvements, to eliminate or minimize the problems identified and to implement those proposals. Criteria were sought for the evaluation of these proposals and the results were analysed. Due to external factors, not all proposals or solutions were applied. Therefore, a plan was developed for their implementation and subsequent analysis and evaluation of their results. Revisions to preventive maintenance plans were made and an internal procedure was developed as part of the improvement propositions. In conclusion, the main objectives of this work were achieved and considering all proposed solutions, significant costs reduction was achieved. Future research and work were proposed to proceed and improve some of the problems identified in this thesis.O presente trabalho foi desenvolvido no âmbito de um estágio curricular na Gestamp Aveiro, com o principal objetivo de reduzir os custos de manutenção associados à linha de produção de estampagem a quente. Para a execução deste relatório foi feito um estudo profundo de toda a linha (desde a entrada da matéria-prima no processo até ao término da peça final), com o objetivo de identificar o maior número possível de problemas existentes, relacionados com desgaste precoce ou falha repetitiva dos equipamentos. Investigaram-se as causas e consequências dessas falhas. De seguida, foi avaliado o impacto de cada um dos problemas identificados, sendo o critério a percentagem do orçamento de manutenção que representavam. Também foram analisadas tentativas de melhoria e outras investigações realizadas pela própria empresa. As áreas de atuação catalogadas como mais relevantes foram o desgaste dos rolos cerâmicos no forno e as suas implicações, o desgaste excessivo das prensas de referenciação dos formatos e a contaminação excessiva do chão de fábrica por pó metálico, proveniente do corte laser, com especial impacto no desgaste dos componentes da cabeça de corte laser. Após a análise e avaliação preliminar, foram propostas e implementadas melhorias para eliminar ou minimizar os problemas identificados. Procuraram-se critérios para avaliar estas propostas e analisaram-se os resultados obtidos. Devido a fatores externos, nem todas as propostas foram aplicadas, sendo que se concebeu um plano de implementação para posterior análise e avaliação dos seus resultados. Foram feitas propostas de revisão dos planos de manutenção preventiva e desenvolveu-se um procedimento interno, como parte das propostas de melhorias. Em conclusão, os objetivos principais propostos neste trabalho foram concluídos com sucesso, resultando poupanças significativas nos custos de operação da empresa. Foram identificados e propostos trabalhos futuros que procedem a este trabalho desenvolvido.Mestrado em Engenharia Mecânic

Desenvolvemento de modelos de información de infraestructuras segundo estándares abertos e parametrización automática a partir de datos xeomáticos.

It seeks to develop procedures that allow generating information models of these structures, created from the relevant information of the point clouds obtained with these systems. For this purpose, the BIM standards for civil engineering structures, both currently available and those that will be published for the duration of the thesis, will be exploited and adopted. Information modeling techniques will be used in these standards, with the aim of obtaining a system that allows modeling the structures automatically. The models will also be made compatible with other methodologies designed for BIM, whose purpose is to take full advantage of the information available for management and maintenance tasks. Meeting these objectives, an automatic modeling system will be developed according to the BIM standards for transport infrastructures, suitable for automatic feeding from geomatic data and remote sensing, which is in turn integrable into management and maintenance systems for these types of structures of civil engineering.Esta tesis busca el desarrollo de metodologías para la exportación de la información geomática de infraestructuras de transporte, particularmente estructuras ferroviarias y carreteras, obtenida mediante tecnologías de mapeado móvil. Se busca desarrollar procedimientos que permitan generar modelos de información de estas estructuras, creados a partir de la información relevante de las nubes de puntos obtenidas con estos sistemas. Con este propósito, se explotarán y adoptarán los estándares BIM para estructuras de ingeniería civil, tanto los actualmente disponibles como aquellos que serán publicados durante la duración de la tesis. Se utilizarán técnicas de modelado de información en estos estándares, con objetivo de obtener un sistema que permita realizar un modelado de las estructuras de manera automática. Se llevará a cabo también la compatibilización los modelos con otras metodologías diseñadas para BIM, cuyo propósito es el aprovechamiento total de la información disponible para tareas de gestión y mantenimiento. Cumpliendo estos objetivos se desarrollará un sistema automático de modelado según los estándares BIM para infraestructuras de transporte, apto para su alimentación automática a partir de datos geomáticos y teledetección, el cual es a su vez integrable en sistemas de gestión y mantenimiento para este tipo de estructuras de ingeniería civil.Esta tese busca o desenvolvemento de metodoloxías para a exportación da información xeomática de infraestruturas de transporte, particularmente estruturas ferroviarias e estradas, obtida mediante tecnoloxías de mapeado móbil. A tese busca o desenvolvemento de procedementos que permitan xerar modelos de información destas estruturas, creados a partir da información relevante das nubes de puntos obtidas con estes sistemas. Con este propósito, se explotarán e adoptarán os estándares BIM para estruturas de enxeñería civil, tanto os actualmente dispoñibles como aqueles que serán publicados durante a duración da tese. Utilizaranse técnicas de modelado de información nestes estándares, con obxectivo de obter un sistema que permita realizar un modelado das estruturas de maneira automática. Levarase a cabo tamén a compatibilización dos modelos con outras metodoloxías diseñadas para BIM, cuxo propósito é o aproveitamento total da información dispoñible para tarefas de xestión e mantemento. Cumplindo estes obxectivos se desenvolverá un sistema automático de modelado segundo os estándares BIM para infraestruturas de transporte, apto para a súa alimentación automática a partir de datos xeomáticos e teledetección, o cal é a súa vez integrable en sistemas de xestión e mantemento para este tipo de estruturas de enxeñería civil

Computer vision reading on stickers and direct part marking on horticultural products : challenges and possible solutions

Traceability of products from production to the consumer has led to a technological advancement in product identification. There has been development from the use of traditional one-dimensional barcodes (EAN-13, Code 128, etc.) to 2D (two-dimensional) barcodes such as QR (Quick Response) and Data Matrix codes. Over the last two decades there has been an increased use of Radio Frequency Identification (RFID) and Direct Part Marking (DPM) using lasers for product identification in agriculture. However, in agriculture there are still considerable challenges to adopting barcodes, RFID and DPM technologies, unlike in industry where these technologies have been very successful. This study was divided into three main objectives. Firstly, determination of the effect of speed, dirt, moisture and bar width on barcode detection was carried out both in the laboratory and a flower producing company, Brandkamp GmbH. This study developed algorithms for automation and detection of Code 128 barcodes under rough production conditions. Secondly, investigations were carried out on the effect of low laser marking energy on barcode size, print growth, colour and contrast on decoding 2D Data Matrix codes printed directly on apples. Three different apple varieties (Golden Delicious, Kanzi and Red Jonaprince) were marked with various levels of energy and different barcode sizes. Image processing using Halcon 11.0.1 (MvTec) was used to evaluate the markings on the apples. Finally, the third objective was to evaluate both algorithms for 1D and 2D barcodes. According to the results, increasing the speed and angle of inclination of the barcode decreased barcode recognition. Also, increasing the dirt on the surface of the barcode resulted in decreasing the successful detection of those barcodes. However, there was 100% detection of the Code 128 barcode at the company’s production speed (0.15 m/s) with the proposed algorithm. Overall, the results from the company showed that the image-based system has a future prospect for automation in horticultural production systems. It overcomes the problem of using laser barcode readers. The results for apples showed that laser energy, barcode size, print growth, type of product, contrast between the markings and the colour of the products, the inertia of the laser system and the days of storage all singularly or in combination with each other influence the readability of laser Data Matrix codes and implementation on apples. There was poor detection of the Data Matrix code on Kanzi and Red Jonaprince due to the poor contrast between the markings on their skins. The proposed algorithm is currently working successfully on Golden Delicious with 100% detection for 10 days using energy 0.108 J mm-2 and a barcode size of 10 × 10 mm2. This shows that there is a future prospect of not only marking barcodes on apples but also on other agricultural products for real time production

Automated freeform assembly of threaded fasteners

Over the past two decades, a major part of the manufacturing and assembly market has been driven by its customer requirements. Increasing customer demand for personalised products create the demand for smaller batch sizes, shorter production times, lower costs, and the flexibility to produce families of products - or different parts - with the same sets of equipment. Consequently, manufacturing companies have deployed various automation systems and production strategies to improve their resource efficiency and move towards right-first-time production. However, many of these automated systems, which are involved with robot-based, repeatable assembly automation, require component- specific fixtures for accurate positioning and extensive robot programming, to achieve flexibility in their production. Threaded fastening operations are widely used in assembly. In high-volume production, the fastening processes are commonly automated using jigs, fixtures, and semi-automated tools. This form of automation delivers reliable assembly results at the expense of flexibility and requires component variability to be adequately controlled. On the other hand, in low- volume, high- value manufacturing, fastening processes are typically carried out manually by skilled workers. This research is aimed at addressing the aforementioned issues by developing a freeform automated threaded fastener assembly system that uses 3D visual guidance. The proof-of-concept system developed focuses on picking up fasteners from clutter, identifying a hole feature in an imprecisely positioned target component and carry out torque-controlled fastening. This approach has achieved flexibility and adaptability without the use of dedicated fixtures and robot programming. This research also investigates and evaluates different 3D imaging technology to identify the suitable technology required for fastener assembly in a non-structured industrial environment. The proposed solution utilises the commercially available technologies to enhance the precision and speed of identification of components for assembly processes, thereby improving and validating the possibility of reliably implementing this solution for industrial applications. As a part of this research, a number of novel algorithms are developed to robustly identify assembly components located in a random environment by enhancing the existing methods and technologies within the domain of the fastening processes. A bolt identification algorithm was developed to identify bolts located in a random clutter by enhancing the existing surface-based matching algorithm. A novel hole feature identification algorithm was developed to detect threaded holes and identify its size and location in 3D. The developed bolt and feature identification algorithms are robust and has sub-millimetre accuracy required to perform successful fastener assembly in industrial conditions. In addition, the processing time required for these identification algorithms - to identify and localise bolts and hole features - is less than a second, thereby increasing the speed of fastener assembly