5,616 research outputs found

    Case-based reasoning in design: An apologia

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    Three positions are presented and defended: the process of generating solutions in problem solving is viewable as a design task; case-based reasoning is a strong method of problem solving; and a synergism exists between case-based reasoning and design problem solving

    The NASA SBIR product catalog

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    The purpose of this catalog is to assist small business firms in making the community aware of products emerging from their efforts in the Small Business Innovation Research (SBIR) program. It contains descriptions of some products that have advanced into Phase 3 and others that are identified as prospective products. Both lists of products in this catalog are based on information supplied by NASA SBIR contractors in responding to an invitation to be represented in this document. Generally, all products suggested by the small firms were included in order to meet the goals of information exchange for SBIR results. Of the 444 SBIR contractors NASA queried, 137 provided information on 219 products. The catalog presents the product information in the technology areas listed in the table of contents. Within each area, the products are listed in alphabetical order by product name and are given identifying numbers. Also included is an alphabetical listing of the companies that have products described. This listing cross-references the product list and provides information on the business activity of each firm. In addition, there are three indexes: one a list of firms by states, one that lists the products according to NASA Centers that managed the SBIR projects, and one that lists the products by the relevant Technical Topics utilized in NASA's annual program solicitation under which each SBIR project was selected

    Reliability of Power Electronic Systems for EV/HEV Applications

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    Computational Tools and Facilities for the Next-Generation Analysis and Design Environment

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    This document contains presentations from the joint UVA/NASA Workshop on Computational Tools and Facilities for the Next-Generation Analysis and Design Environment held at the Virginia Consortium of Engineering and Science Universities in Hampton, Virginia on September 17-18, 1996. The presentations focused on the computational tools and facilities for analysis and design of engineering systems, including, real-time simulations, immersive systems, collaborative engineering environment, Web-based tools and interactive media for technical training. Workshop attendees represented NASA, commercial software developers, the aerospace industry, government labs, and academia. The workshop objectives were to assess the level of maturity of a number of computational tools and facilities and their potential for application to the next-generation integrated design environment

    Design of smart tool organizer

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    The increasing demand for compact and energy efficient machines and mechanisms, led to the emergence of a series of scalable instruments and devices used for testing, storage, manufacturing, and prototyping. The emergence of these devices indeed provided the flexibility and low capital cost that were necessary for product development and personal use. Furthermore, the demand is expected to proliferate to all domestic and industrial sectors of the economy, which brings us to the subject of the current investigation. The main objective of the proposed project is the design and prototyping of a compact electromechanical smart tool organizer that is capable of storing, tracking personal use and availability of machine shop tools in the college of Mathematics and Science at the University of Central Oklahoma. The proposed design incorporates a micro-controlled electro-mechanical dispensing unit, an interactive digital interface with key activation and a database for data collection & tracking of tools and personnel users. The dispensing unit consists of a CNC machine, linear actuator and a 3D printed mechanical clamp which enables the unit to efficiently hold and move various tools to the desired location. The skeleton of the CNC machine is assembled using five stainless steel v-slots operating on a belt and pinion system. Pinons are fitted to NEMA 17 stepper motors to achieve 2D motion by converting rotational motion to linear motion using a belt driven actuator. The assembly of the CNC machine utilizes various gantry plates to hold v-slots in position along with providing mounts for stepper motors and linear actuator. The linear actuator acts as a third axis which allows the motion of the dispensing unit to operate in three directions. This provides mobility to the machine to precisely take the mechanical clamp to a predetermined position within the frame of the dispensing unit. The design of mechanical clamp includes assembly of the base of the clamp, rack and pinion system, two gripper arms and a servo motor. The pinion converts the rotational motion to linear motion of the racks enabling the grip to open and close as required. The final assembly of the mechanical clamp is mounted on the linear actuator using the 3D printed mount bracket on the base of the clamp. The electronics and controls of the smart tool organizer includes low and high voltage operating components such as Nema 17 stepper motors, MG996R servo, linear actuator, limit switches, buck converter, DS3231 RTC module, SD card module, L298N motor drive module, TB6600 motor drivers, a 7” touch screen LED display and an arduino mega. The firmware arduino IDE is used to program these electronic components and ASCII is used to program the Interactive GUI and HMI on the Nextion display which connect to arduino using serial port and synchronizes to achieve the goal of the smart tool organizer

    Computer aided inspection procedures to support smart manufacturing of injection moulded components

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    This work presents Reverse Engineering and Computer Aided technologies to improve the inspection of injection moulded electro-mechanical parts. Through a strong integration and automation of these methods, tolerance analysis, acquisition tool-path optimization and data management are performed. The core of the procedure concerns the automation of the data measure originally developed through voxel-based segmentation. This paper discusses the overall framework and its integration made according to Smart Manufacturing requirements. The experimental set-up, now in operative conditions at ABB SACE, is composed of a laser scanner installed on a CMM machine able to measure components with lengths in the range of 5Ă·250 mm, (b) a tool path optimization procedure and (c) a data management both developed as CAD-based applications

    Electro-optic architecture for servicing sensors and actuators in advanced aircraft propulsion systems

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    A detailed design of a fiber optic propulsion control system, integrating favored sensors and electro-optics architecture is presented. Layouts, schematics, and sensor lists describe an advanced fighter engine system model. Components and attributes of candidate fiber optic sensors are identified, and evaluation criteria are used in a trade study resulting in favored sensors for each measurand. System architectural ground rules were applied to accomplish an electro-optics architecture for the favored sensors. A key result was a considerable reduction in signal conductors. Drawings, schematics, specifications, and printed circuit board layouts describe the detailed system design, including application of a planar optical waveguide interface

    Workshop on "Robotic assembly of 3D MEMS".

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    Proceedings of a workshop proposed in IEEE IROS'2007.The increase of MEMS' functionalities often requires the integration of various technologies used for mechanical, optical and electronic subsystems in order to achieve a unique system. These different technologies have usually process incompatibilities and the whole microsystem can not be obtained monolithically and then requires microassembly steps. Microassembly of MEMS based on micrometric components is one of the most promising approaches to achieve high-performance MEMS. Moreover, microassembly also permits to develop suitable MEMS packaging as well as 3D components although microfabrication technologies are usually able to create 2D and "2.5D" components. The study of microassembly methods is consequently a high stake for MEMS technologies growth. Two approaches are currently developped for microassembly: self-assembly and robotic microassembly. In the first one, the assembly is highly parallel but the efficiency and the flexibility still stay low. The robotic approach has the potential to reach precise and reliable assembly with high flexibility. The proposed workshop focuses on this second approach and will take a bearing of the corresponding microrobotic issues. Beyond the microfabrication technologies, performing MEMS microassembly requires, micromanipulation strategies, microworld dynamics and attachment technologies. The design and the fabrication of the microrobot end-effectors as well as the assembled micro-parts require the use of microfabrication technologies. Moreover new micromanipulation strategies are necessary to handle and position micro-parts with sufficiently high accuracy during assembly. The dynamic behaviour of micrometric objects has also to be studied and controlled. Finally, after positioning the micro-part, attachment technologies are necessary

    Modular and Reconfigurable 3D Micro-Optical Benches : Concept, Validation and Characterization.

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    International audienceIn this paper, we present an approach to design MOEMS based on Reconfigurable Free Space Micro-Optical Benches (RFS-MOB). The proposed concept enables to design modular and reconfigurable MOEMS by using a generic structure of silicon holders and non defined position in the substrate. Various micro-optical elements, e.g. microlenses or micromirrors, can be integrated within holders. Their assembly is achieved with an active microgripper, after high precision alignement within guiding rails of silicon substrate. Flexible parts are used to maintain a final position. The concept is validated by successful assembly of holders. A characterization method of assembled holders is proposed and provides an accuracy better than 0.04 for an angle measurement

    Development of a Flying Robot With a Pantograph-Based Variable Wing Mechanism

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    We develop a flying robot with a new pantograph-based variable wing mechanism for horizontal-axis rotorcrafts (cyclogyro rotorcrafts). A key feature of the new mechanism is to have a unique trajectory of variable wings that not only change angles of attack but also expand and contract according to wing positions. As a first step, this paper focuses on demonstrating the possibility of the flying robot with this mechanism. After addressing the pantograph-based variable wing mechanism and its features, a simulation model of this mechanism is constructed. Next, we present some comparison results (between the simulation model and experimental data) for a prototype body with the proposed pantograph-based variable wing mechanism. Both simulation and experimental results show that the flying robot with this new mechanism can generate enough lift forces to keep itself in the air. Furthermore, we construct a more precise simulation model by considering rotational motion of each wing. As a result of optimizing design parameters using the precise simulation model, flight performance experimental results demonstrate that the robot with the optimal design parameters can generate not only enough lift forces but a 155 gf payload as well
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