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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 1,531 records · Page 85
All sourcesNASA NTRSDOE OSTI
NASA NTRS2011

NASA Ares I Launch Vehicle Roll and Reaction Control Systems Lessons Learned

On April 15, 2010 President Barak Obama made the official announcement that the Constellation Program, which included the Ares I launch vehicle, would be canceled. NASA s Ares I launch vehicle was being designed to launch the Orion Crew Exploration Vehicle, returning humans to the moon, Mars, and beyond. It consisted of a First Stage (FS) five segment solid rocket booster and a liquid J-2X Upper Stage (US) engine. Roll control for the FS was planned to be handled by a dedicated Roll Control System (RoCS), located on the connecting interstage. Induced yaw or pitch moments experienced during FS ascent would have been handled by vectoring of the booster nozzle. After FS booster separation, the US Reaction Control System (ReCS) would have provided the US Element with three degrees of freedom control as needed. The lessons learned documented in this paper will be focused on the technical designs and producibility of both systems along with the partnership between NASA and Boeing, who was on contract to build the Ares I US Element, which included the FS RoCS and US ReCS. In regards to partnership, focus will be placed on integration along with technical work accomplished by Boeing with special emphasis on each task order. In summary, this paper attempts to capture key lessons learned that should be helpful in the development of future launch vehicle RCS designs.

Butt, Adam↗
DOE OSTI2015

Method to control deposition rate instabilities—High power impulse magnetron sputtering deposition of TiO{sub 2}

The authors describe how changes in shutter state (open/closed) affect sputter plasma conditions and stability of the deposition rate of Ti and TiO{sub 2} films. The films were grown by high power impulse magnetron sputtering in pure Ar and in Ar/O{sub 2} mixture from a metallic Ti target. The shutter state was found to have an effect on the pulse waveform for both pure Ar and reactive sputtering of Ti also affecting stability of TiO{sub 2} deposition rate. When the shutter opened, the shape of pulse current changed from rectangular to peak-plateau and pulse energy decreased. The authors attribute it to the change in plasma impedance and gas rarefaction originating in geometry change in front of the magnetron. TiO{sub 2} deposition rate was initially found to be high, 1.45 Å/s, and then dropped by ∼40% during the first 5 min, while for Ti the change was less obvious. Instability of deposition rate poses significant challenge for growing multilayer heterostructures. In this work, the authors suggest a way to overcome this by monitoring the integrated average energy involved in the deposition process. It is possible to calibrate and control the film thickness by monitoring the integrated pulse energy and end growth when desired integrated pulse energy level has been reached.

42 ENGINEERING↗
DOE OSTI2019

Autonomous Maintenance of Digital Equipment

The application of Industry 4.0 concepts to the digitization of machine tools is considered. Organizational and technological principles fundamental to new machine-tool properties, including smart and autonomous control, are outlined. The creation of digital images and digital twins of machine tools simulating their internal processes is discussed. The characteristics and behavior of machine tools over the whole life cycle are analyzed.

42 ENGINEERING↗
NASA NTRS2018

Sixth NASA Glenn Research Center Propulsion Control and Diagnostics (PCD) Workshop

The Intelligent Control and Autonomy Branch at NASA Glenn Research Center hosted the Sixth Propulsion Control and Diagnostics Workshop on August 22-24, 2017. The objectives of this workshop were to disseminate information about research being performed in support of NASA Aeronautics programs; get feedback from peers on the research; and identify opportunities for collaboration. There were presentations and posters by NASA researchers, Department of Defense representatives, and engine manufacturers on aspects of turbine engine modeling, control, and diagnostics.

Collaboration↗
DOE OSTI2014

Decision making based on optical excitation transfer via near-field interactions between quantum dots

Optical near-field interactions between nanostructured matters, such as quantum dots, result in unidirectional optical excitation transfer when energy dissipation is induced. This results in versatile spatiotemporal dynamics of the optical excitation, which can be controlled by engineering the dissipation processes and exploited to realize intelligent capabilities such as solution searching and decision making. Here, we experimentally demonstrate the ability to solve a decision making problem on the basis of optical excitation transfer via near-field interactions by using colloidal quantum dots of different sizes, formed on a geometry-controlled substrate. We characterize the energy transfer behavior due to multiple control light patterns and experimentally demonstrate the ability to solve the multi-armed bandit problem. Our work makes a decisive step towards the practical design of nanophotonic systems capable of efficient decision making, one of the most important intellectual attributes of the human brain.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2021

Model Predictive Fault-Tolerant Tracking Control for PDF Control Systems With Packet Losses

In this article, a fault-tolerant tracking control strategy is investigated for nonlinear probability density function (PDF) control systems with the actuator fault, uncertainties, unknown disturbance, and random packet losses. The control input signal dropout and measurement signal dropouts are described as the independent Bernoulli distribution. An adaptive fault diagnosis (FD) observer based on the Lyapunov function is given to simultaneously estimate the fault, disturbance, and state with packet losses. Furthermore, different from the traditional robust fault-tolerant control (FTC), a new active fault-tolerant tracking controller is designed based on the model predictive control framework, which has better adaptive fault-tolerant performance. Finally, the validity of the proposed FTC method has been proved by a simulation study of a papermaking process.

42 ENGINEERING↗
DOE OSTI2024

Optimized piston temperature control in gaseous fuel hydrogen engine system

Operating a gaseous fuel engine system includes combusting a mixture containing a gaseous hydrogen fuel and air in a cylinder of an engine, varying an operating parameter of the engine to which a crown surface temperature of a piston within the cylinder is responsive, and populating a temperature model based on a value of the varied operating parameter. Operating a gaseous fuel engine system further includes operating an oil spray apparatus to spray oil onto the piston based on the populated temperature model, and maintaining the crown surface temperature of the piston between a high temperature limit and a pre-ignition mitigation temperature limit based on the operating of the oil spray apparatus. Related apparatus and control logic is also disclosed.

Bochart, Michael R.↗
DOE OSTI2020

Extremum seeking for optimal control problems with unknown time-varying systems and unknown objective functions

We consider the problem of optimal feedback control of an unknown, noisy, time-varying, dynamic system that is initialized repeatedly. Examples include a robotic manipulator which must perform the same motion, such as assisting a human, repeatedly and accelerating cavities in particle accelerators which are turned on for a fraction of a second with given initial conditions and vary slowly due to temperature fluctuations. In this paper, we present an approach that applies to systems of practical interest. The method presented here is model independent; does not require knowledge of the objective function; is robust to measurement noise; is applicable for any set of initial conditions; is applicable to simultaneously controlling an arbitrary number of parameters; and may be implemented with a broad range of continuous or discontinuous functions such as sine or square waves. For systems with convex cost functions we prove that our algorithm will produce controllers that approach the minimal cost. For linear systems we reproduce the cost minimizing linear quadratic regulator optimal controller that could have been designed analytically had the system and cost function been known. We demonstrate the effectiveness of the algorithm with simulation studies of noisy and time-varying systems.

42 ENGINEERING↗
DOE OSTI2015

Experience of Implementing a Distributed Control System for Thermal and Mechanical and Electrical Equipment at the South-West CHP

Results of implementing an SPPA-T3000-based unified distributed control system for thermal and mechanical and electrical equipment at the South-West CHP are discussed. Hardware solutions for integration with local control systems, control of electrical equipment in compliance with the standards IEC 61850, Modbus RTU, and communication between the plant control system and the System Operator of the Unified Power System are described.

24 POWER TRANSMISSION AND DISTRIBUTION↗
DOE OSTI2018

Control Signals of a Predictive Industrial PID Controller

To expand the functional capabilities of industrial controllers for systems subject to external disturbances, developments to date are reviewed, and an approach permitting the generation of control signals on the basis of predictions is proposed and tested. The benefits of this approach are assessed. It is best used for large industrial equipment and systems in manufacturing and the oil and gas industry.

42 ENGINEERING↗
NASA NTRS1987

Application of several variable-valve-timing concepts to an LHR engine

The paper discusses advantages provided by electronically controlled hydraulically activated valves (ECVs) when applied to low heat rejection (LHR) engines. The ECV concept provides additional engine control flexibility by allowing for a variable valve timing as a function of speed and load, or for a given transient condition. The results of a study carried out to assess the benefits that this flexibility can offer to an LHR engine indicated that, when judged on the benefits to BSFC, volumetric efficiency, and peak firing pressure, ECVs would provide only modest benefits in comparison to conventional valve profiles. It is noted, however, that once installed on the engine, the ECVs would permit a whole range of certain more sophisticated variable valve timing strategies not otherwise possible, such as high compression cranking, engine braking, cylinder cutouts, and volumetric efficiency timing with engine speed.

Morel, T.↗
DOE OSTI2024

Machine learning-guided discovery of gas evolving electrode bubble inactivation

The adverse effects of electrochemical bubbles on the performance of gas-evolving electrodes are well known, but studies on the degree of adhered bubble-caused inactivation, and how inactivation changes during bubble evolution are limited. We study electrode inactivation caused by oxygen evolution while using surface engineering to control bubble formation. We find that the inactivation of the entire projected area, as is currently believed, is a poor approximation which leads to non-physical results. Using a machine learning-based image-based bubble detection method to analyze large quantities of experimental data, we show that bubble impacts are small for surface engineered electrodes which promote high bubble projected areas while maintaining low direct bubble contact. We thus propose a simple methodology for more accurately estimating the true extent of bubble inactivation, which is closer to the area which is directly in contact with the bubbles.

Lake, Jack R.↗
NASA NTRS1973

The results of a high-speed wind tunnel test to investigate the effects of the NASA refan JT8D engine nacelles on the stability and control characteristics of the Boeing 727 airplane

A high speed wind tunnel test was conducted to investigate the effects of the NASA Refan JT8D engine nacelles on the stability and control characteristics of the Boeing 727 airplane. The test was performed at the Calspan Corporation 8x8 ft. (2.44x2.44 m.) transonic wind tunnel. Both the 727-200 and -100 models were tested. A small nose-down pitching moment increment and a slight increase in longitudinal stability were noted due to the Refan nacelles. The directional stability of the 727-200 airplane increased up to 10 percent. A smaller improvement was observed on the 727-100 model. In general, the high speed stability and control characteristics of the basic airplane are not significantly altered by the Refan nacelle installation.

Kupcis, E. A.↗
DOE OSTI2013

Embedded Sensors and Controls to Improve Component Performance and Reliability - System Dynamics Modeling and Control System Design

This report documents the current status of the modeling, control design, and embedded control research for the magnetic bearing canned rotor pump being used as a demonstration platform for deeply integrating instrumentation and controls (I&C) into nuclear power plant components. This pump is a highly inter-connected thermo/electro/mechanical system that requires an active control system to operate. Magnetic bearings are inherently unstable system and without active, moment by moment control, the rotor would contact fixed surfaces in the pump causing physical damage. This report details the modeling of the pump rotordynamics, fluid forces, electromagnetic properties of the protective cans, active magnetic bearings, power electronics, and interactions between different dynamical models. The system stability of the unforced and controlled rotor are investigated analytically. Additionally, controllers are designed using proportional derivative (PD) control, proportional integral derivative (PID) control, voltage control, and linear quadratic regulator (LQR) control. Finally, a design optimization problem that joins the electrical, mechanical, magnetic, and control system design into one problem to balance the opposing needs of various design criteria using the embedded system approach is presented.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗
NASA NTRS2008

Inductive System Monitors Tasks

The Inductive Monitoring System (IMS) software developed at Ames Research Center uses artificial intelligence and data mining techniques to build system-monitoring knowledge bases from archived or simulated sensor data. This information is then used to detect unusual or anomalous behavior that may indicate an impending system failure. Currently helping analyze data from systems that help fly and maintain the space shuttle and the International Space Station (ISS), the IMS has also been employed by data classes are then used to build a monitoring knowledge base. In real time, IMS performs monitoring functions: determining and displaying the degree of deviation from nominal performance. IMS trend analyses can detect conditions that may indicate a failure or required system maintenance. The development of IMS was motivated by the difficulty of producing detailed diagnostic models of some system components due to complexity or unavailability of design information. Successful applications have ranged from real-time monitoring of aircraft engine and control systems to anomaly detection in space shuttle and ISS data. IMS was used on shuttle missions STS-121, STS-115, and STS-116 to search the Wing Leading Edge Impact Detection System (WLEIDS) data for signs of possible damaging impacts during launch. It independently verified findings of the WLEIDS Mission Evaluation Room (MER) analysts and indicated additional points of interest that were subsequently investigated by the MER team. In support of the Exploration Systems Mission Directorate, IMS is being deployed as an anomaly detection tool on ISS mission control consoles in the Johnson Space Center Mission Operations Directorate. IMS has been trained to detect faults in the ISS Control Moment Gyroscope (CMG) systems. In laboratory tests, it has already detected several minor anomalies in real-time CMG data. When tested on archived data, IMS was able to detect precursors of the CMG1 failure nearly 15 hours in advance of the actual failure event. In the Aeronautics Research Mission Directorate, IMS successfully performed real-time engine health analysis. IMS was able to detect simulated failures and actual engine anomalies in an F/A-18 aircraft during the course of 25 test flights. IMS is also being used in colla

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DOE OSTI2015

Present status of Stacy modification program and fundamental nuclear properties of experimental cores related to fuel debris criticality - 14264

A modification program of the Static Experiment Critical Facility, STACY is now undergoing in Japan Atomic Energy Agency, JAEA, in order to accumulate fundamental critical data relating the critical control technology for fuel debris treatment in the Fukushima Daiichi Nuclear Power Station, 1FNPS. In accordance with the new regulatory requirement for research reactors established by Nuclear Regulation Authority of Japan, NRA in December 2013, fundamental design policies and basic nuclear properties of STACY have been confirmed for the critical experiments which are oriented to research on criticality control in the 1FNPS. Reactivity control in the STACY experiments is made by adjusting the water level in a core tank. The moderating ratio of the heterogeneous system which determines neutron spectrum can be adjusted by changing lattice plates. Safety review by NRA for revised basic design started in March, 2015. This paper described main specifications of experimental cores for license procedure, the availability of re activity control system, and the range of nuclear characteristics such as reactivity control, reactivity coefficients and kinetic parameters, which dominate static and transient characteristics of the STACY cores. (authors)

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗
DOE OSTI2016

Spatially Resolved Thermal Transport Measurements in PyC Coated Fuel Particles

Self-regulating, low-power, compact, nuclear reactors are of immense interest to a community of sponsors who have power needs in space, underwater and in remote areas. Recent exploratory studies have provided valuable understanding into the underlying physics of self-regulation, including, how a material's self-regulation (or reactivity feedback) can be controlled by engineering its micro-scale and mesoscale properties. The approach being explored at Los Alamos National Laboratory involves a core matrix that is constructed of fuel kernels dispersed in a graphite matrix. The timing of the feedback is influenced by thermal properties of the fuel composite, which can be 'tuned' by micro-engineering. A pyrolytic carbon (PyC) layer coats the kernels to ensure that during a reactivity spike, the majority of the heat is trapped within the fuel kernel. The resulting precipitous temperature rise triggers a strong negative Doppler feedback. The ability to measure the local thermal properties of the individual materials that compose the fuel particle are crucial to fully understanding and controlling this feedback mechanism. The work covered in this presentation involves using laser-based thermal wave microscopy to measure the local thermal properties of the fuel particles. Specifically we measure the thermal conductivity and diffusivity of the fuel kernel and the PyC layer as well as the contact resistance between the kernel and the PyC layer. (authors)

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗
NASA NTRS1966

The Lunar Orbiter: A Spacecraft to Advance Lunar Exploration

The film describes the Lunar Orbiter's mission to photograph landing areas on the Moon. The Orbiter will be launched from Cape Kennedy using an Atlas Agena booster rocket. Once it is boosted in a trajectory toward the Moon, the Orbiter will deploy two-way earth communication antennas and solar panels for electricity. Attitude control jets will position the solar panels toward the sun and a tracker for a fix on its navigational star. The Orbiter will be put in an off-center orbit around the Moon where it will circle from four to six days. Scientists on Earth will study the effects of the Moon's gravitational field on the spacecraft, then the orbit will be lowered to 28 miles above the Moon's surface. Engineers will control the Orbiter manually or by computer to activate two camera lenses. The cameras will capture pictures of 12,000 square miles of lunar surface in 25 and 400 square mile increments. Pictures will be sent back to Earth using solar power to transmit electrical signals. The signals will be received by antennas at Goldstone, CA, and in Australia and Spain. Incoming photographic data will be electronically converted and processed to produce large-scale photographic images. The mission will be directed from the Space Flight Operations Facility in Pasadena, CA by NASA and Boeing engineers. After the photographic mission, the Orbiter will continue to circle the Moon providing information about micrometeoroids and radiation in the vicinity.

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