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A Guide to APU Health Management

2023-09-15
AIR5317A
AIR5317 establishes the foundation for developing a successful APU health management capability for any commercial or military operator, flying fixed wing aircraft or rotorcraft. This AIR provides guidance for demonstrating business value through improved dispatch reliability, fewer service interruptions, and lower maintenance costs and for satisfying Extended Operations (ETOPS) availability and compliance requirements.
Technical Paper

A Military Space Plane Candidate

1997-10-01
975630
This paper presents a Military Space Plane design concept. While the current military space plane activity is focused on rocket-powered concepts, the concept presented here is powered by a rocket-based combined cycle engine that uses both rocket and air-breathing engine cycles. The design concept is the reference SSTO design concept used in the NASA HRST ANSER study. The reference concept is a derivative of the NASA air-breathing Access to Space study SSTO design concept. The Access to Space air-breathing vehicle's combined cycle engine was replaced by the Aerojet rocket-based combined cycle engine. The orbital performance capability of the reference design concept is presented for 100 n mi., polar, and 225 n mi., 51 deg. orbits. The sensitivity of GTOW to payload and margin is also presented.
Journal Article

A Novel Cloud-Based Additive Manufacturing Technique for Semiconductor Chip Casings

2022-08-02
Abstract The demand for contactless, rapid manufacturing has increased over the years, especially during the COVID-19 pandemic. Additive manufacturing (AM), a type of rapid manufacturing, is a computer-based system that precisely manufactures products. It proves to be a faster, cheaper, and more efficient production system when integrated with cloud-based manufacturing (CBM). Similarly, the need for semiconductors has grown exponentially over the last five years. Several companies could not keep up with the increasing demand for many reasons. One of the main reasons is the lack of a workforce due to the COVID-19 protocols. This article proposes a novel technique to manufacture semiconductor chips in a fast-paced manner. An algorithm is integrated with cloud, machine vision, sensors, and email access to monitor with live feedback and correct the manufacturing in case of an anomaly.
Journal Article

A Novel Flight Dynamics Modeling Using Robust Support Vector Regression against Adversarial Attacks

2023-03-24
Abstract An accurate Unmanned Aerial System (UAS) Flight Dynamics Model (FDM) allows us to design its efficient controller in early development phases and to increase safety while reducing costs. Flight tests are normally conducted for a pre-established number of flight conditions, and then mathematical methods are used to obtain the FDM for the entire flight envelope. For our UAS-S4 Ehecatl, 216 local FDMs corresponding to different flight conditions were utilized to create its Local Linear Scheduled Flight Dynamics Model (LLS-FDM). The initial flight envelope data containing 216 local FDMs was further augmented using interpolation and extrapolation methodologies, thus increasing the number of trimmed local FDMs of up to 3,642. Relying on this augmented dataset, the Support Vector Machine (SVM) methodology was used as a benchmarking regression algorithm due to its excellent performance when training samples could not be separated linearly.
Article

Advanced simulation using the digital twin to achieve electromagnetic compatibility and electrification management in a modern UAS

2022-01-13
The aerospace industry is facing immense challenges due to increased design complexity and higher levels of integration, particularly in the electrification of aircraft. These challenges can easily impact program cost and product time to market. System electrification and electromagnetic compatibility (EMC) have become critical issues today. In the context of 3D electromagnetics, EMC electromagnetic compatibility ensures the original equipment manufacturer (OEM) that radiated emissions from various electronic devices, such as avionics or the entire aircraft for that matter, do not interfere with other electronic products onboard the aircraft.
Magazine

Aerospace & Defense Technology: December 2020

2020-12-01
How Solid-State Technology Impacts A&D Equipment Testing The Role of Prototype/Test Systems in Next-Generation C5ISR Development Using Advanced Computational Engineering Software to Meet Aerospace & Defense Industry Challenges How Advanced Vacuum Bag Kits Streamline Composite Parts Manufacturing Replacing Multiple RF Receivers with Just One Using Channelization Air Force Technology Tracks "Sporadic E" Progress on Zirconia-Polyurea Matrix Hybrid Composites Incorporating zirconia particles into polyurea elastomers to form hybrid composites and designing them into state-of-the-art body armor has the potential to achieve lightweight ballistic efficiency. Bioenvironmental Engineering Guide for Composite Materials Developing a comprehensive baseline for identifying, evaluating, and controlling occupational and environmental hazards associated with composite fibers and materials for base-level Bioenvironmental Engineering (BE) personnel.
Magazine

Aerospace & Defense Technology: February 2020

2020-01-30
Rad-Hard Microelectronics for Space Applications Outsourcing Plasma Treatments for Surface Modification Adding Context to Full-Motion Video for Improved Surveillance and Situational Awareness Implementing an Aerospace Factory of the Future 90° Hybrid Coupled Power Amplifier - Pros and Cons A New Network Design for the "Internet from Space" Future Advances in Electronic Materials and Processes - Flexible Hybrid Electronics Despite progress being made, there are still significant obstacles to the manufacture and use of flexi-ble hybrid electronics in military applications. Heterogeneous Integration Technology Integrating different types of devices and materials could increase their functional density, improving the performance of electro-optic systems for sensor applications. The Impact of Cyber Cameras on the Intelligence Community The ability to covertly access and manipulate cyber cameras could provide valuable strategic data for the US intelligence community.
Magazine

Aerospace & Defense Technology: October 2019

2019-10-01
Artificial Intelligence and Autonomous Vehicles A "STEP" Forward for Product Lifecycle Management The Challenge of Replacing Hard Chrome Defining an Open System Architecture Standard for Defense Systems Solid-State Microwave Power Module Defeating Commercial Drone Threats with Open-Source SDR Influence of Leading-Edge Oscillatory Blowing on Time-Accurate Dynamic Store Separation Developing an understanding of, and potentially controlling, pitch bifurcation of a store release from an aircraft during flight could improve weapons delivery. Green's Function Extraction from Atmospheric Acoustic Propagation Understanding what affects acoustic waves propagating in the atmosphere is important for a variety of military applications including the development of new remote sensing techniques.
Standard

Aerospace Ground Equipment Criteria for a Propellant Transfer Unit

1999-01-01
AIR1129
The primary purpose of a Propellant Transfer Unit (PTU) is to temperature-condition and weigh a specific amount of propellant, and transfer if to a vehicle propellant tank. A secondary purpose of a PTU may be to drain propellant from the vehicle tank and return it to the transfer unit when required. The transfer unit may also be used for flushing the vehicle fill lines and transfer unit with appropriate flushing fluids, followed with nitrogen for the purpose of drying the lines and weigh tank. The transfer unit may include provisions for helium purging of the propellant transfer tank and lines, ad supplying a blanket of helium pressure to the transfer tank. Each PTU consists of a piping system with appropriate propellant and pneumatic valves, regulators, relief valves, filters and a propellant pump. Various components such as a scrubber, bubbler, propellant cooler (heat exchanger), propellant weigh tank, weigh scale and a chiller may make up the balance of the assembly.
Standard

Aircraft Flotation Analysis

2022-12-20
AIR1780B
This document is divided into five parts. The first part deals with flotation analysis features and definitions to acquaint the engineer with elements common to the various methods and the meanings of the terms used. The second part identifies and describes current flotation analysis methods. Due to the close relationship between flotation analysis and runway design, methods for the latter are also included in this document. As runway design criteria are occasionally used for flotation evaluation, including some for runways built to now obsolete criteria, a listing of the majority of these criteria constitutes the third part. The fourth part of this document tabulates the most relevant documents, categorizing them for commercial and civil versus military usage, by military service to be satisfied, and by type of pavement. This document concludes with brief elaborations of some concepts for broadening the analyst’s understanding of the subject.
Journal Article

Algorithm Development for Avoiding Both Moving and Stationary Obstacles in an Unstructured High-Speed Autonomous Vehicular Application Using a Nonlinear Model Predictive Controller

2020-10-19
Abstract The advancement in vision sensors and embedded technology created the opportunity in autonomous vehicles to look ahead in the future to avoid potential obstacles and steep regions to reach the target location as soon as possible and yet maintain vehicle safety from rollover. The present work focuses on developing a nonlinear model predictive controller (NMPC) for a high-speed off-road autonomous vehicle, which avoids undesirable conditions including stationary obstacles, moving obstacles, and steep regions while maintaining the vehicle safety from rollover. The NMPC controller is developed using CasADi tools in the MATLAB environment. The CasADi tool provides a platform to formulate the NMPC problem using symbolic expressions, which is an easy and efficient way of solving the optimization problem. In the present work, the vehicle lateral dynamics are modeled using the Pacejka nonlinear tire model.
Book

Automatic Target Recognition, Third Edition

2018-01-01
This third edition of Automatic Target Recognition provides a roadmap for breakthrough ATR designs―with increased intelligence, performance, and autonomy. Clear distinctions are made between military problems and comparable commercial deep-learning problems. These considerations need to be understood by ATR engineers working in the defense industry as well as by their government customers. A reference design is provided for a next-generation ATR that can continuously learn from and adapt to its environment. The convergence of diverse forms of data on a single platform supports new capabilities and improved performance. This third edition broadens the notion of ATR to multisensor fusion. Radical continuous-learning ATR architectures, better integration of data sources, well-packaged sensors, and low-power teraflop chips will enable transformative military designs.
Technical Paper

Challenging Power Density Requirements for Future Fighter APUs

1991-09-01
912177
Future fighters will require more compact, lighter weight, small gas turbine auxiliary power units (APUs) capable of faster starting, and operation, up to altitudes of 50,000 ft. The US Air Force is currently supporting an Advanced Components Auxiliary Power Unit (ACAPU) research program to demonstrate the technologies that will be required to accomplish projected secondary power requirements for these advanced fighters. The requirements of the ACAPU Program represent a challenging task requiring significant technical advancements over the current state-of-the-art, prominent among which are: Small high heat release high altitude airbreathing combustors. High temperature monolithic ceramic and metallic small turbines. Capability to operate, and transition from non-airbreathing to airbreathing modes. This paper discusses these challenging requirements and establishes technology paths to match and exceed the required goals.
Technical Paper

Computing Remaining Fatigue Life Under Incrementally Updated Loading Histories

2018-04-03
2018-01-0623
After manufacture, every military vehicle experiences a unique history of dynamic loads, depending on loads carried, missions completed, etc. Damage accumulates in vehicle structures and components accordingly, leading eventually to failures that can be difficult to anticipate, and to unpredictable consequences for mission objectives. The advent of simulation-based fatigue life prediction tools opens a path to Digital Twin based solutions for tracking damage, and for gaining control over vehicle reliability. An incremental damage updating feature has now been implemented in the Endurica CL fatigue solver with the aim of supporting such applications for elastomer components. The incremental updating feature is demonstrated via the example of a simple transmission mount component. The damage state of the mount is computed as it progresses towards failure under a series of typical loading histories.
Journal Article

Conceptualizing an Urban Operations Vehicle within a Comprehensive Research and Development Program

2023-09-07
Abstract In the last decades we have witnessed an increasing number of military operations in urban environments. Complex urban operations require high standards of training, equipment, and personnel. Emergency forces on the ground will need specialized vehicles to support them in all parts and levels of this extremely demanding environment including the subterranean and interior of infrastructure. The development of vehicles for this environment has lagged but offers a high payoff. This article describes the method for developing a concept for an urban operations vehicle by characterization of the urban environment, deduction of key issues, evaluation of related prototyping, science fiction story-typing of the requirements for such a vehicle, and comparison with field-proven and scalable solutions. Embedding these thoughts into a comprehensive research and development program provides lines of development, setting the stage for further research.
Standard

Cybersecurity Guidebook for Cyber-Physical Vehicle Systems

2016-01-14
J3061_201601
This recommended practice provides guidance on vehicle Cybersecurity and was created based off of, and expanded on from, existing practices which are being implemented or reported in industry, government and conference papers. The best practices are intended to be flexible, pragmatic, and adaptable in their further application to the vehicle industry as well as to other cyber-physical vehicle systems (e.g., commercial and military vehicles, trucks, busses). Other proprietary Cybersecurity development processes and standards may have been established to support a specific manufacturer’s development processes, and may not be comprehensively represented in this document, however, information contained in this document may help refine existing in-house processes, methods, etc. This recommended practice establishes a set of high-level guiding principles for Cybersecurity as it relates to cyber-physical vehicle systems.
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