NASA Tech Briefs, August 2010

Topics covered include: Technology Focus: Mechanical Components; Electronics/Computers; Software; Materials; Mechanics/Machinery; Manufacturing; Bio-Medical; Physical Sciences; Information Sciences; and Books and Reports

Remaining useful life and fault detection models for high voltage electrical connectors focused on predictive maintenance

In recent years, industries have chosen to invest in technology with the aim of making their processes more efficient and thus offering market products of higher quality. Nowadays it is very common for companies to use special systems to predict failures and avoid unexpected delays, reduction of costs, etc. SBI Connectors, along with the Universitat Politècnica de Catalunya, have been collaborating to develop research projects for more than 10 years. As a result of the collaboration with the university, patents and international publications have been generated, which have helped to situate and reinforce SBI Connectors leadership in the international market while offering an image of scientific-technical credibility. This research is carried out, with the collaboration of SBI connectors and Universitat Politècnica de Catalunya, in order to develop the Smartconnector project (within the Retos de Colaboración Spanish research frame). The thesis proposed by the author is dedicated to develop and validate RUL (Remaining Useful Life) and fault detection approaches for electrical substation connectors. The RUL approach proposed in this work is based on a simple and accurate model of the degradation with time of the electrical resistance of the connector (main health indicator), which has two parameters, whose values are identified from on-line acquired data. Next, the fault detection chapter is divided into two parts. The first part presents an on-line condition monitoring method to predict early failures in power connectors from on-line acquired data in conjunction with another parametric degradation model of the resistance of the connector, whose parameters are identified by means of the Markov chain Monte Carlo stochastic method. The second part presents, analyzes and compares the performance of three simple and effective methods for online determination of the State of Health (SoH) of power connectors with low computational requirements. The proposed approaches are based on monitoring the evolution of the connectors’ electrical resistance, which determines the degradation trajectory. Furthermore, this work includes an in-depth study of the temperature dependence of the electrical contact resistance (ECR). To analyze and validate results presented in this work, data is acquired in real time, including main parameters such as the electrical current and voltage drop across the terminals of the connector, conductor and connector temperature, thus estimating the phase shift between voltage drop and electrical current waveforms and the contact resistance by means of accelerated aging tests (ADT).En los últimos años, la industria ha optado por invertir en tecnología con el objetivo de hacer más eficientes sus procesos y así ofrecer al mercado productos de mayor calidad. Hoy en día es muy habitual que las empresas utilicen sistemas especiales para predecir fallos y evitar retrasos inesperados, reducción de costes, etc. SBI connectors, junto con la Universitat Politècnica de Catalunya, colaboran para desarrollar proyectos de investigación desde hace más de 10 años. Fruto de la colaboración con la universidad se han generado patentes y publicaciones internacionales, que han ayudado a situar y reforzar el liderazgo de SBI Connectors en el mercado internacional, al tiempo que ofrece una imagen de credibilidad científico-técnica. Esta tesis doctoral se realiza con la colaboración de SBI connectors y la Universitat Politècnica de Catalunya, para desarrollar el proyecto Smartconnector (dentro del marco de investigación Retos de Colaboración). La tesis propuesta por el autor está dedicada a desarrollar y validar modelos de RUL (Remaining Useful Life) y detección de fallos para conectores de subestaciones eléctricas enfocador al mantemiento predictive. El enfoque RUL propuesto en este trabajo se basa en un modelo simple y preciso de la degradación de la resistencia eléctrica del conector respecto al tiempo (indicador principal de salud), el cual tiene dos parámetros cuyos valores se identifican a partir de datos adquiridos en línea. A continuación, el capítulo de detección de fallos se divide en dos partes. En la primera parte se presenta un método de monitoreo en línea de condición para predecir fallos tempranos en conectores de potencia a partir de datos adquiridos en línea en conjunto con otro modelo paramétrico de degradación de la resistencia del conector, cuyos parámetros son identificados por medio del algoritmo de Markov Chain Monte Carlo. La segunda parte presenta, analiza y compara las prestaciones de tres métodos simples y efectivos para la determinación en línea del Estado de Salud (SoH) de conectores de potencia con bajos requerimientos computacionales. Los enfoques propuestos se basan en el seguimiento de la evolución de la resistencia eléctrica de los conectores, que determina la trayectoria de degradación. Además, este trabajo incluye un estudio en profundidad de la dependencia de la temperatura de la resistencia eléctrica de contacto (ECR). Para analizar y validar todo el trabajo presentado, se adquieren datos en tiempo real, incluyendo parámetros principales como la corriente eléctrica y la caída de tensión en los terminales del conector, la temperatura del conductor y del conector, estimando así el desfase entre la caída de tensión y la tensión eléctrica, forma de onda de corriente y la resistencia de contacto por medio de ensayos de envejecimiento acelerado (ADT).Postprint (published version

Design Development Test and Evaluation (DDT and E) Considerations for Safe and Reliable Human Rated Spacecraft Systems

A team directed by the NASA Engineering and Safety Center (NESC) collected methodologies for how best to develop safe and reliable human rated systems and how to identify the drivers that provide the basis for assessing safety and reliability. The team also identified techniques, methodologies, and best practices to assure that NASA can develop safe and reliable human rated systems. The results are drawn from a wide variety of resources, from experts involved with the space program since its inception to the best-practices espoused in contemporary engineering doctrine. This report focuses on safety and reliability considerations and does not duplicate or update any existing references. Neither does it intend to replace existing standards and policy

Cumulative index to NASA Tech Briefs, 1986-1990, volumes 10-14

Tech Briefs are short announcements of new technology derived from the R&D activities of the National Aeronautics and Space Administration. These briefs emphasize information considered likely to be transferrable across industrial, regional, or disciplinary lines and are issued to encourage commercial application. This cumulative index of Tech Briefs contains abstracts and four indexes (subject, personal author, originating center, and Tech Brief number) and covers the period 1986 to 1990. The abstract section is organized by the following subject categories: electronic components and circuits, electronic systems, physical sciences, materials, computer programs, life sciences, mechanics, machinery, fabrication technology, and mathematics and information sciences

NASA Tech Briefs, June 2000

Topics include: Computer-Aided Design and Engineering; Electronic Components and Circuits; Electronic Systems; Test and Measurement; Physical Sciences; Materials; Computer Programs; Computers and Peripherals

NASA Tech Briefs, October 1990

Topics: New Product Ideas; NASA TU Services; Electronic Components and Circuits; Electronic Systems; Physical' Sciences; Materials; Computer Programs; Mechanics; Machinery; Fabrication Technology; Mathematics and Information Sciences; Life Sciences

On-Board Electronic Control Systems of Future Automated Heavy Machinery

The level of automation and wireless communication has increased in heavy machinery recently. This requires utilizing new devices and communication solutions in heavy machinery applications which involve demanding operating conditions and challenging life-cycle management. Therefore, the applied devices have to be robust and hardware architectures flexible, consisting of generic modules. In research and development projects devices that have various communication interfaces and insufficient mechanical and electrical robustness need to be applied. Although this thesis has its main focus on machines utilized as research platforms, many of the challenges are similar with commercial machines.The applicability of typical solutions for data transfer is discussed. Controller area network with a standardized higher level protocol is proposed to be applied where data signalling rates above 1 Mb/s are not required. The main benefits are the availability of robust, generic devices and well-established software tools for configuration management. Ethernet can be utilized to network equipment with high data rates, typically used for perception. Although deterministic industrial Ethernet protocols would fulfil most requirements, the conventional internet protocol suite is likely to be applied due to device availability.Sometimes sensors and other devices without a suitable communication interface need to be applied. In addition, device-related real-time processing or accurate synchronization of hardware signals may be required. A small circuit board with a microcontroller can be utilized as a generic embedded module for building robust, small and cost-efficient prototype devices that have a controller area network interface. Although various microcontroller boards are commercially available, designing one for heavy machinery applications, in particular, has benefits in robustness, size, interfaces, and flexible software development. The design of such a generic embedded module is presented.The device-specific challenges of building an automated machine are discussed. Unexpected switch-off of embedded computers has to be prevented by the control system to avoid file system errors. Moreover, the control system has to protect the batteries against deep discharge when the engine is not running. With many devices, protective enclosures with heating or cooling are required.The electronic control systems of two automated machines utilized as research platforms are presented and discussed as examples. The hardware architectures of the control systems are presented, following the proposed communication solutions as far as is feasible. Several applications of the generic embedded module within the control systems are described. Several research topics have been covered utilizing the automated machines. In this thesis, a cost-efficient operator-assisting functionality of an excavator is presented and discussed in detail.The results of this thesis give not only research institutes but also machine manufacturers and their subcontractors an opportunity to streamline the prototyping of automated heavy machinery

Technology 2001: The Second National Technology Transfer Conference and Exposition, volume 2

Proceedings of the workshop are presented. The mission of the conference was to transfer advanced technologies developed by the Federal government, its contractors, and other high-tech organizations to U.S. industries for their use in developing new or improved products and processes. Volume two presents papers on the following topics: materials science, robotics, test and measurement, advanced manufacturing, artificial intelligence, biotechnology, electronics, and software engineering

Wings in Orbit: Scientific and Engineering Legacies of the Space Shuttle, 1971-2010

The Space Shuttle is an engineering marvel perhaps only exceeded by the station itself. The shuttle was based on the technology of the 1960s and early 1970s. It had to overcome significant challenges to make it reusable. Perhaps the greatest challenges were the main engines and the Thermal Protection System. The program has seen terrible tragedy in its 3 decades of operation, yet it has also seen marvelous success. One of the most notable successes is the Hubble Space Telescope, a program that would have been a failure without the shuttle's capability to rendezvous, capture, repair, as well as upgrade. Now Hubble is a shining example of success admired by people around the world. As the program comes to a close, it is important to capture the legacy of the shuttle for future generations. That is what "Wings In Orbit" does for space fans, students, engineers, and scientists. This book, written by the men and women who made the program possible, will serve as an excellent reference for building future space vehicles. We are proud to have played a small part in making it happen. Our journey to document the scientific and engineering accomplishments of this magnificent winged vehicle began with an audacious proposal: to capture the passion of those who devoted their energies to its success while answering the question "What are the most significant accomplishments?" of the longestoperating human spaceflight program in our nation s history. This is intended to be an honest, accurate, and easily understandable account of the research and innovation accomplished during the era