Index to 1984 NASA Tech Briefs, volume 9, numbers 1-4

Short announcements of new technology derived from the R&D activities of NASA are presented. These briefs emphasize information considered likely to be transferrable across industrial, regional, or disciplinary lines and are issued to encourage commercial application. This index for 1984 Tech B Briefs contains abstracts and four indexes: subject, personal author, originating center, and Tech Brief Number. The following areas are covered: electronic components and circuits, electronic systems, physical sciences, materials, life sciences, mechanics, machinery, fabrication technology, and mathematics and information sciences

Safety of Lithium Nickel Cobalt Aluminum Oxide Battery Packs in Transit Bus Applications

The future of mass transportation is clearly moving toward the increased efficiency and greenhouse gas reduction of hybrid and electric vehicles. With the introduction of high-power/high-energy storage devices such as lithium ion battery systems serving as a key element in the system, valid safety and security concerns emerge. This is especially true when the attractive high-specific-energy and power-chemistry lithium nickel cobalt aluminum oxide (NCA) is used. This chemistry provides great performance but presents a safety and security risk when used in large quantities, such as for a large passenger bus. If triggered, the cell can completely fuel its own fire, and this triggering event occurs more easily than one may think. To assist engineers and technicians in this transfer from the use of primarily fossil fuels to battery energy storage on passenger buses, the Battery Application Technology Testing and Energy Research Laboratory (BATTERY) of the Thomas D. Larson Pennsylvania Transportation Institute (LTI) in the College of Engineering at The Pennsylvania State University partnered with advanced chemistry battery and material manufacturers to study the safety concerns of an NCA battery chemistry for use in transit buses. The research team ran various experiments on cells and modules, studying rarely considered thermal events or venting events. Special considerations were made to gather supporting information to help better understand what happens, and most importantly how to best mitigate these events and/or manage them when they occur on a passenger bus. The research team found that the greatest safety concern when using such a high-energy chemistry is ensuring passenger safety when a cell’s electrolyte boils and causes the ventilation of high-temperature toxic material. A cell-venting event can be triggered by a variety of scenarios with differing levels of likelihood. Also, though the duration of a venting event is relatively short, on the order of just a few seconds, the temperature of the venting material and cell is extremely high. During a venting event, the high-pressure, burning gases tend to burn holes in nearby packaging materials. Most interestingly, the team discovered that following a venting event the large-format cells tested immediately reached and remained at extremely high external skin temperatures for very long periods, on the order of hours. The majority of this report covers the testing designed to better understand how high-energy cells of this chemistry fail and what materials can be used to manage these failures in a way that increases passenger survivability

Development of a powertrain control algorithm for a compound-split diesel hybrid-electric vehicle

The goal of this research was to develop a unique powertrain control algorithm for a diesel-powered compound-split hybrid crossover utility vehicle (CUV) and evaluate the fuel consumption and greenhouse gas emissions benefits that can be realized compared to existing non-hybrid, gasoline-powered CUVs. This was achieved through the implementation of engine on/off functionality, regenerative braking, and electric-only drive. The research was conducted in conjunction with the university\u27s participation in EcoCAR: The NeXt Challenge, an inter-collegiate advanced vehicle engineering competition focused on developing alternatively powered vehicles in the interest of providing improved fuel efficiency and reduced tailpipe emissions while maintaining useful vehicle functionality. Prior to construction, the proposed vehicle was simulated for fuel efficiency and carbon dioxide emissions using the Powertrain System Analysis Toolkit. Initial simulation results indicated that the proposed compound-split hybrid vehicle would achieve 35 mpgge combined fuel economy and produce carbon dioxide at a rate of 242 g/mi. A 2009 Saturn Vue was modified to accept the proposed hybrid powertrain consisting of a 1.3 liter diesel engine, 2-mode compound-split transaxle, and lithium-ion high-voltage battery system. This vehicle served as the platform for the development and validation of the powertrain control algorithm. Using the vehicle\u27s CAN communication capabilities, auxiliary control units were integrated to manage the new powertrain components and implement the control strategy. The project vehicle and control algorithm were validated and tested on-road for fuel efficiency and performance. The final powertrain control algorithm developed through this research included automatic engine start/stop, regenerative braking, and full-electric driving capability at speeds up to 25 mph. In its final configuration, the WVU 2-mode hybrid-electric vehicle achieved city/highway fuel economy of 24.5/31.5 mpgge. Compared to the base vehicle, the project vehicle achieved a 28.9% improvement in city fuel economy, a 21.2% improvement in highway fuel economy, and a 20% reduction of in-use CO2 emissions

Index to NASA Tech Briefs, 1975

This index contains abstracts and four indexes--subject, personal author, originating Center, and Tech Brief number--for 1975 Tech Briefs

Testialustan suunnittelu hybridiajoneuvojen hardware-in-the-loop simulaatioihin

Recent changes to vehicle type-approval regulations have increased demand for testing methods, which better represent real-world driving conditions. Hardware-in-the-Loop (HIL) simulation is seen as an attractive alternative for pure simulations and real-world operation measurements. The goal of this work was to provide a functional testbed for engine testing, as well as for HIL simulations of Hybrid Electric Vehicles (HEVs). In addition, a state-of-the-art review of HIL was considered an important goal of the work. The theory behind HIL, and real-time systems in general, is depicted using a wide variety of examples from automotive applications relating to hybrid power sources. The knowledge gained from the literature was used to design and build a testbed in a form of an engine dynamometer. The testbed can be used to emulate rotational forces, such as load torques on a driveshaft. The testbed’s fast hardware connections enable real-time testing. The scope of the design was in mechanical design and in specification of the hardware components. Initial Internal Combustion Engine (ICE) steady-state and transient tests were done to partially validate the testbed. However, the performance was assessed to not be at an acceptable level. For example, only speed tracking passed the non-road transient cycle tracking assessment. Torque tracking and the derived power curves failed the assessment narrowly. However, the test results indicate that with proper tuning of the control software, the system performance should get better. The system response was slow at this point, but the transient behavior itself was fast. Also, in steady-state, torque and speed ripple were low. Only the preparations for HIL simulation were carried out, since the testbed was not validated to be functional enough for the much more demanding HIL tests. The preparations involved building a simulation model of a series-parallel hybrid Refuse-Collecting Vehicle (RCV), which is to be used for the verification of the designed system’s HIL capabilities. The model was independently verified to be suitable to be used for the physical tests.Viimeaikaiset muutokset ajoneuvojen tyyppihyväksyntään ovat lisänneet tarvetta testausmetodeille, jotka paremmin vastaavat oikean elämän ajo-olosuhteita. HIL-simulaatio nähdään houkuttelevana vaihtoehtona pelkälle simulaatiolle sekä ajoneuvon ajonaikaisille mittauksille. Tämän työn tavoitteena on tarjota toimiva testilaite moottoridynamometritestaukseen sekä hybridiajoneuvojen HIL-simulaatioihin. Lisäksi, HIL:in nykytilanteen kuvausta pidettiin tärkeänä työn tavoitteena. HIL:in, ja yleisemmin reaaliaikaisen testauksen, tausta ja teoria selvitettiin laaja alaisesti käyttäen esimerkkejä hybridivoimanlähteisiin liittyvistä ajoneuvoalan käyttökohteista. Kirjallisuutta hyödyntäen, testipenkki suunniteltiin ja rakennettiin. Testipenkkiä voidaan käyttää emuloimaan pyöriviä voimia, kuten vetoakseliin kohdistuvia vääntöjä. Testipenkin nopeat yhteydet mahdollistavat reaaliaikaisen testauksen. Suunnittelu oli rajattu pääasiassa mekaaniseen suunnitteluun ja komponenttien määrittelyyn. Sähkö- ja ohjelmistosuunnittelu määriteltiin yleisellä tasolla. Alustavat polttomoottorilla tehdyt vakaiden ajopisteiden ja transienttiajojen testit toteutettiin testipenkin osittaiseksi validoinniksi. Kuitenkin, laitteen suorituskyky ei yltänyt halutulle tasolle. Esimerkiksi, ainoastaan nopeusseuranta läpäisi transienttiajo testin, mutta vääntö- ja voimaseurannat epäonnistuivat täpärästi. Tulokset kuitenkin osoittavat luottamusta siitä että testipenkki saadaan aikanaan halutulle tasolle ohjelmistopuolen kontrollereja säätämällä. Tällä hetkellä systeemin vasteaika on liian pitkä, vaikka muuten dynamiikka on nopeaa. Lisäksi, vakaissa ajopisteissä vääntö- ja nopeushuojunta ovat alhaisia. Ainoastaan valmistelut HIL-simulaatiota varten saatiin toteutettua, sillä testipenkkiä ei saatu reaaliaikasta testausta vaativalle tasolle. Valmistelut sisälsivät hybridijäteauton simulaatiomallin rakentamisen, jota tullaan aikanaan käyttämään testipenkin HIL toimivuuden validointiin. Simulaatiomalli varmistettiin itsenäisenä toimivaksi, ja siten soveltuvaksi tuleviin fyysisiin testiajoihin

Comprehensive concept-phase system safety analysis for hybrid-electric vehicles utilizing automated driving functions

2019 Summer.Includes bibliographical references.Automotive system safety (SS) analysis involving automated driving functions (ADFs) and advanced driver assistance systems (ADAS) is an active subject of research but highly proprietary. A comprehensive SS analysis and a risk informed safety case (RISC) is required for all complex hybrid-vehicle builds especially when utilizing ADFs and ADAS. Industry standard SS procedures have been developed and are accessible but contain few detailed instructions or references for the process of completing a thorough automotive SS analysis. In this work, a comprehensive SS analysis is performed on an SAE-Level 2 autonomous hybrid-vehicle architecture in the concept phase which utilizes lateral and longitudinal automated corrective control actions. This paper first outlines a proposed SS process including a cross-functional SS working group procedure, followed by the development of an item definition inclusive of the ADFs and ADAS and an examination of 5 hazard analysis and risk assessment (HARA) techniques common to the automotive industry that were applied to 11 vehicle systems, and finally elicits the safety goals and functional requirements necessary for safe vehicle operation. The results detail functional failures, causes, effects, prevention, and mitigation methods as well as the utility of, and instruction for completing the various HARA techniques. The conclusion shows the resulting critical safety concerns for an SAE Level-2 autonomous system can be reduced through the use of the developed list of 116 safety goals and 950 functional safety requirements

A 3D Framework for Characterizing Microstructure Evolution of Li-Ion Batteries

Lithium-ion batteries are commonly found in many modern consumer devices, ranging from portable computers and mobile phones to hybrid- and fully-electric vehicles. While improving efficiencies and increasing reliabilities are of critical importance for increasing market adoption of the technology, research on these topics is, to date, largely restricted to empirical observations and computational simulations. In the present study, it is proposed to use the modern technique of X-ray microscopy to characterize a sample of commercial 18650 cylindrical Li-ion batteries in both their pristine and aged states. By coupling this approach with 3D and 4D data analysis techniques, the present study aimed to create a research framework for characterizing the microstructure evolution leading to capacity fade in a commercial battery. The results indicated the unique capabilities of the microscopy technique to observe the evolution of these batteries under aging conditions, successfully developing a workflow for future research studies

Automated in-row weed trimmer

The Automated In-Row Weed Trimmer, or AIRWT, is a weed removal system designed to be used in vineyards in order to enable safe and e cient removal of weeds while preventing damage to the vines. The goal of the system is to reduce the need for the use of manual labor and herbicides while improving production rates of grapes by automating the weed removal process at vineyards. By implementing an automated system for weed removal, the team aims to resolve ethical issues in food production, primarily those surrounding human labor, environmental friendliness, and social sustainability. The focus of this report is to explore in depth the AIRWT system concept as well as its subsystems, in addition to reviewing its product development cycle

Phase 1 of the near term hybrid passenger vehicle development program

In order to meet project requirements and be competitive in the 1985 market, the proposed six-passenger vehicle incorporates a high power type Ni-Zn battery, which by making electric-only traction possible, permits the achievement of an optimized control strategy based on electric-only traction to a set battery depth of discharge, followed by hybrid operation with thermal primary energy. This results in a highly efficient hybrid propulsion subsystem. Technical solutions are available to contain energy waste by reducing vehicle weight, rolling resistance, and drag coefficient. Reproaching new 1985 full size vehicles of the conventional type with hybrids of the proposed type would result in a U.S. average gasoline saving per vehicle of 1,261 liters/year and an average energy saving per vehicle of 27,133 MJ/year