6,486 research outputs found

    NASA Automated Rendezvous and Capture Review. Executive summary

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    In support of the Cargo Transfer Vehicle (CTV) Definition Studies in FY-92, the Advanced Program Development division of the Office of Space Flight at NASA Headquarters conducted an evaluation and review of the United States capabilities and state-of-the-art in Automated Rendezvous and Capture (AR&C). This review was held in Williamsburg, Virginia on 19-21 Nov. 1991 and included over 120 attendees from U.S. government organizations, industries, and universities. One hundred abstracts were submitted to the organizing committee for consideration. Forty-two were selected for presentation. The review was structured to include five technical sessions. Forty-two papers addressed topics in the five categories below: (1) hardware systems and components; (2) software systems; (3) integrated systems; (4) operations; and (5) supporting infrastructure

    Viking '75 spacecraft design and test summary. Volume 3: Engineering test summary

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    The engineering test program for the lander and the orbiter are presented. The engineering program was developed to achieve confidence that the design was adequate to survive the expected mission environments and to accomplish the mission objective

    The next stage of naval electrical engineering system testing at the Power Networks Demonstration Centre

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    This paper gives an overview of the Power Hardware in the Loop (PHIL) system, that is now operational at the PNDC (a University of Strathclyde Research Centre), to extend the centres capability for marine electrical system testing. In this paper, the key components of the PHIL system and their corresponding interfaces are presented; representative case studies showing typical applications for the PHIL system at the PNDC are illustrated; and the next stage of future marine power system testing (flywheel energy storage) utilising the PHIL platform is discussed. The objective of this test bed is to: facilitate integration of engineering systems into marine power system platforms; support the development of future electric ships; to de-risk the integration of the next generation of energy weapons and sensors; and to supplement and replace the need for ship demonstrators. This facility development and associated project plan involves a productive mix of industry, academia, UK MoD and US DoD. The two key components of the PHIL test bed are: (1) A Real Time Digital Simulator (RTDS) system that is capable of simulating marine electrical systems in real time; and (2) A Triphase converter, a uniquely modular solution that can be re-configured for AC and DC output, used as the link between simulation and real hardware under test. The RTDS interface with the Triphase converter system employs fibre communication to issue control commands and receive measurement feedback. The hardware to be tested, connected to the Triphase, is interfaced directly to simulation in real time. In this paper it is demonstrated how a flywheel energy storage device could be directly connected to a simulated ship power system and operated in real time. This test setup would be used to evaluate the interaction between the ship power system and flywheel. This test bed can be reconfigured for long term research and development for a multitude of ship power system solutions. The ship power system is represented in simulation which means it can be modified to represent existing or planned ship architectures. This facilitates testing of hardware planned for retrofit in existing ship power systems; and it allows future ship powers systems to be simulated and interfaced with existing hardware. Both options support reduced cost and life cycle time to develop ship power systems

    Feasibility study of the Boeing Small Research Module (BSRM) concept

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    The design, capabilities, and subsystem options for the Boeing Small Research Module (BSRM) are described. Specific scientific missions are defined based on NASA-Ames Research Center requirements and the BSRM capability to support these missions is discussed. Launch vehicle integration requirements and spacecraft operational features are also presented

    Regression between headmaster leadership, task load and job satisfaction of special education integration program teacher

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    Managing school is a daunting task for a headmaster. This responsibility is exacerbated when it involves the Special Education Integration Program (SEIP). This situation requires appropriate and effective leadership in addressing some of the issues that are currently taking place at SEIP such as task load and job satisfaction. This study aimed to identify the influence of headmaster leadership on task load and teacher job satisfaction at SEIP. This quantitative study was conducted by distributing 400 sets of randomized questionnaires to SEIP teachers across Malaysia through google form. The data obtained were then analyzed using Structural Equation Modeling (SEM) and AMOS software. The results show that there is a significant positive effect on the leadership of the headmaster and the task load of the teacher. Likewise, the construct of task load and teacher job satisfaction has a significant positive effect. However, for the construct of headmaster leadership and teacher job satisfaction, there was no significant positive relationship. This finding is very important as a reference to the school administration re-evaluating their leadership so as not to burden SEIP teachers and to give them job satisfaction. In addition, the findings of this study can also serve as a guide for SEIP teachers to increase awareness of the importance of managing their tasks. This study also focused on education leadership in general and more specifically on special education leadership

    Hydraulic Hybrid Powertrain-In-the-Loop Integration for Analyzing Real-World Fuel Economy and Emissions Improvements

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    The paper describes the approach, addresses integration challenges and discusses capabilities of the Hybrid Powertrain-in-the-Loop (H-PIL) facility for the series/hydrostatic hydraulic hybrid system. We describe the simulation of the open-loop and closed-loop hydraulic hybrid systems in H-PIL and its use for concurrent engineering and development of advanced supervisory strategies. The configuration of the hydraulic-hybrid system and details of the hydraulic circuit developed for the H-PIL integration are presented. Next, software and hardware interfaces between the real components and virtual systems are developed, and special attention is given to linking component-level controllers and system-level supervisory control. The H-PIL setup allows imposing realistic dynamic loads on hydraulic pump/motors and accumulator based on vehicle driving schedule. Application of fast analyzers allows characterization of the impact of dynamic interactions in the propulsion system on engine-out emissions. Therefore, the H-PIL facility allows optimization of the hybrid system for both high-efficiency and low emissions. The impetus is provided by previous work showing that more than half of the soot emissions from a conventional diesel powertrain over the urban driving schedule can be attributed to transients. The setup includes a 6.4L V-8 International diesel engine, highly dynamic dynamometer, Radial piston pump/motors supplied by Bosch-Rexroth and dSPACE real-time environment with in-house developed simulation of the virtual vehicle.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/89880/1/draft_01.pd

    Towards a Powerful Hardware‐in‐the‐Loop System for Virtual Calibration of an Off‐Road Diesel Engine

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    A common challenge among internal combustion engine (ICE) manufacturers is shorten-ing the development time while facing requirements and specifications that are becoming more complex and border in scope. Virtual simulation and calibration are effective instruments in the face of these demands. This article presents the development of zero‐dimensional (0D)—real‐time engine and exhaust after‐treatment system (EAS) models and their deployment on a Virtual test bench (VTB). The models are created using a series of measurements acquired in a real test bench, carefully performed in view of ensuring the highest reliability of the models themselves. A zero‐dimensional approach was chosen to guarantee that models could be run in real‐time and interfaced to the real engine Electronic Control Unit (ECU). Being physically based models, they react to changes in the ECU calibration parameters. Once the models are validated, they are then integrated into a Sim-ulink® based architecture with all the Inputs/Outputs connections to the ECU. This Simulink® model is then deployed on a Hardware in the Loop (HiL) machine for ECU testing and calibration. The results for engine and EAS performance and emissions align with both steady‐state and transient measurements. Finally, two different applications of the HiL system are presented to explain the opportunities and advantages of this tool integrated within the standard engine development. Ex-amples cited refer to altitude calibration activities and soot loading investigation on vehicle duty cycles. The cases described in this work are part of the actual development of one of the latest engines developed by Kohler Engines: the KDI 1903 TCR Stage V. The application of this methodology reveals a great potential for engine development and may become an essential tool for calibration engineers

    Developing a distributed electronic health-record store for India

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    The DIGHT project is addressing the problem of building a scalable and highly available information store for the Electronic Health Records (EHRs) of the over one billion citizens of India

    Spacecraft design project: Low Earth orbit communications satellite

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    This is the final product of the spacecraft design project completed to fulfill the academic requirements of the Spacecraft Design and Integration 2 course (AE-4871) taught at the U.S. Naval Postgraduate School. The Spacecraft Design and Integration 2 course is intended to provide students detailed design experience in selection and design of both satellite system and subsystem components, and their location and integration into a final spacecraft configuration. The design team pursued a design to support a Low Earth Orbiting (LEO) communications system (GLOBALSTAR) currently under development by the Loral Cellular Systems Corporation. Each of the 14 team members was assigned both primary and secondary duties in program management or system design. Hardware selection, spacecraft component design, analysis, and integration were accomplished within the constraints imposed by the 11 week academic schedule and the available design facilities
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