1,348 research outputs found
Integration of a microprobe into a CMM
Various microprobes have been developed in the last decade to address the
needs of micrometrology. However, most microprobes are only employed in specialized
measuring machines located in a few research institutes and are not widespread in the
industry. This work aims to extend the capabilities of conventional coordinate
measuring machines (CMMs) towards measuring microgeometries through the low-cost
integration of a tactile microprobe. In order to demonstrate this, a gear measuring
instrument (GMI), which is a commercial CMM not specialized for measurements at the
microscale, has been equipped with a recently developed silicon-membrane-based
microprobe. In the first part of this work, the working principle of the microprobe, its
assembly and its integration into the GMI are described. Two different mounting setups
of the microprobe onto the GMI were evaluated and tested. Measurements on the GMI
were performed solely with the microprobe or by combining the microprobe and the
measurement system already present on the GMI. This combination makes it possible to
use the microprobe advantageously and to exchange it in a comfortable semi-automatic
way. To test these two mounting setups, a new involute scanning artifact (SAFT) with
superimposed waviness was measured
Design of a Hand Held Minimally Invasive Lung Tumour Localization Device
Lung cancer is the leading type of cancer that causes death. If diagnosed, the treatment of choice is surgical resection of the tumour. Traditionally, a surgeon feels for the presence of a tumour in open thoracic surgery. However, a minimally invasive approach is desired. A major problem presented by the minimally invasive approach is the localization of the tumour.
This project describes the design, analysis, and experimental validation of a novel minimally invasive instrument for lung tumour localization. The instrument end effector is a two degree of freedom lung tissue palpator. It allows for optimal tissue palpation to increase useful sensor feedback by ensuring sensor contact, and prevents tissue damage by uniformly distributing pressure on the tissue with an upper bound force. Finite element analysis was used extensively to guide the design process. The mechanism is actuated using high strength tungsten cables attached to controlled motors. Heat treatment experiments were undertaken with stainless steel alloy 440C for use in the design, achieving a device factor of safety of 4. This factor of safety is based on a 20 N force on the end effector — the approximate weight of a human lung.
The design was prototyped and validation experiments were carried out to assess its articulation and its load carrying capacity. Up to 10 N of force was applied to the prototype. Issues to resolve in the current design include cable extension effects and the existence of joint inflection.
The end effector was also designed to allow the inclusion of ultrasound, tactile, and kinaesthetic sensors. It is hypothesized that a plurality of sensors will increase the likelihood of positive tumour localization. These sensors, combined with the presented mechanical design, form the basis for research in robotics-assisted palpation. A proof of concept control system is presented for automated palpation
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Modular Systems For Fabrication: Toward A Collaborative Partnership Between Humans and Machines
In recent decades, considerable advances have allowed more people to use digital fabrication techniques such as 3D Printing to create personal artifacts. Instead of collaborating with humans to create a design, current fabrication machines, however, mostly follow humans’ commands as one step input in order to output a physical object as a batch process. This way of working presents three big challenges: end-users without special knowledge can not fully appreciate advances of digital fabrication, machines cannot understand people’s design activities during the creative process with improvisation, and fabrication machines are not designed to be collaborative to support individuals’ creative processes with in-situ designs.
In this dissertation, I introduce the research to answer the overarching question: “How can humans and machines form a collaborative partnership in a creative process?” I investigate three elements and their influences at the intersections of HCI, digital fabrication, and collaborative systems to address these three main challenges. I present interactive design tools for end-users to design complex moveable objects(Fabrication-HCI), empirical studies to understand individuals’ design abilities and remaining challenges in developing collaborative fab machines (HCI-Collaborative Systems), and a collaborative 3D printer I built to enable close interactions between users and machines through multiple communication channels and various workflows (Fabrication-Collaborative Systems).
I conclude my dissertation with a vision of an intelligent fabrication agent towards the future of people and machines augmenting each other. I propose new research programs for developing an intelligent machine that detects and predicts human behaviors in creative processes, in order to provide various types of assistance depending on the context, such as guidance, recommendation, and teaching new skills.</p
Micro/Nano Manufacturing
Micro- and nano-scale manufacturing has been the subject of ever more research and industrial focus over the past 10 years. Traditional lithography-based technology forms the basis of micro-electro-mechanical systems (MEMS) manufacturing, but also precision manufacturing technologies have been developed to cover micro-scale dimensions and accuracies. Furthermore, these fundamentally different technology platforms are currently combined in order to exploit the strengths of both platforms. One example is the use of lithography-based technologies to establish nanostructures that are subsequently transferred to 3D geometries via injection molding. Manufacturing processes at the micro-scale are the key-enabling technologies to bridge the gap between the nano- and the macro-worlds to increase the accuracy of micro/nano-precision production technologies, and to integrate different dimensional scales in mass-manufacturing processes. Accordingly, this Special Issue seeks to showcase research papers, short communications, and review articles that focus on novel methodological developments in micro- and nano-scale manufacturing, i.e., on novel process chains including process optimization, quality assurance approaches and metrology
From 3D Models to 3D Prints: an Overview of the Processing Pipeline
Due to the wide diffusion of 3D printing technologies, geometric algorithms
for Additive Manufacturing are being invented at an impressive speed. Each
single step, in particular along the Process Planning pipeline, can now count
on dozens of methods that prepare the 3D model for fabrication, while analysing
and optimizing geometry and machine instructions for various objectives. This
report provides a classification of this huge state of the art, and elicits the
relation between each single algorithm and a list of desirable objectives
during Process Planning. The objectives themselves are listed and discussed,
along with possible needs for tradeoffs. Additive Manufacturing technologies
are broadly categorized to explicitly relate classes of devices and supported
features. Finally, this report offers an analysis of the state of the art while
discussing open and challenging problems from both an academic and an
industrial perspective.Comment: European Union (EU); Horizon 2020; H2020-FoF-2015; RIA - Research and
Innovation action; Grant agreement N. 68044
A fiber optic spectrometry system for measuring irradiance distributions in sea ice environments
Author Posting. © American Meteorological Society, 2014. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Atmospheric and Oceanic Technology 31 (2014): 2844–2857, doi:10.1175/JTECH-D-14-00108.1.A fiber optic–based spectrometry system was developed to enable automated, long-term measurements of spectral irradiance in sea ice environments. This system utilizes a single spectrometer module that measures the irradiance transmitted by multiple optical fibers, each coupled to the input fiber of the module via a mechanical rotary multiplexer. Small custom-printed optical diffusers, fixed to the input end of each fiber, allow these probes to be frozen into ice auger holes as small as 5 cm in diameter. Temperature-dependent biases in the spectrometer module and associated electronics were examined down to −40°C using an environmental chamber to identify any artifacts that might arise when operating these electronic and optical components below their vendor-defined lower temperature limits. The optical performance of the entire system was assessed by freezing multiple fiber probes in a 1.2-m-tall ice column, illuminating from above with a light source, and measuring spectral irradiance distributions at different depths within the ice column. Results indicated that the radiometric sensitivity of this fiber-based system is comparable to that of commercially available oceanographic spectroradiometers.This research was supported by the Joint Initiative Awards Fund from the Andrew W. Mellon Foundation, through Woods Hole Oceanographic Institution’s internal Interdisciplinary Study Award program (S. R. L. and T. M.), and by a China scholarship council (CSC) scholarship and the Program for Zhejiang Leading Team of S&T Innovation (Grant 2010R50036) provided to H. W.2015-06-0
Small business innovation research. Abstracts of completed 1987 phase 1 projects
Non-proprietary summaries of Phase 1 Small Business Innovation Research (SBIR) projects supported by NASA in the 1987 program year are given. Work in the areas of aeronautical propulsion, aerodynamics, acoustics, aircraft systems, materials and structures, teleoperators and robotics, computer sciences, information systems, spacecraft systems, spacecraft power supplies, spacecraft propulsion, bioastronautics, satellite communication, and space processing are covered
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