Tech Briefs

Variable-Sweep-Wing Aircraft Configuration

There are significant improvements in structural, aerodynamic, and energy efficiency. Ames Research Center, Moffett Field, California Efficient aircraft designs are increasingly desired in order to support the continued growth of the air transportation industry. Continued expansion of this vital mode of transportation is threatened due to concerns over ever-increasing emissions, noise, and the demand for fuel. Current airport runway, ramp, and terminal facilities are increasingly constrained by encroaching growth and neighborhood environmental issues. The challenges associated with ever-increasing demand for air travel will require the development of aircraft that can fly efficiently over wide speed ranges, minimize their environmental impacts, offer the potential for sizing and growth relative to market demand, and make efficient use of constrained airport and airspace resources.

Posted in: Articles, Briefs, Aviation, Energy Efficiency

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Automated Table Lookup Solution Algorithm of the Optimal Powered Descent Guidance for Planetary Landing

NASA’s Jet Propulsion Laboratory, Pasadena, California A novel automated table lookup method is developed to compute the near-fuel-optimal powered descent guidance trajectories, in real-time, for planetary soft landing. The main advantage of this algorithm is that it can be executed autonomously in milliseconds without performing iterative numerical computations to obtain the solution of the optimization problem. The key enabling idea behind this approach is to store, in a lookup table, a number of optimal trajectories that have been computed on the ground for a systematically chosen set of initial conditions. In flight, a near-fuel-optimal trajectory is computed for the actual initial condition by interpolating between these pre-computed trajectories. The lookup method requires only a small, predetermined number of basic algebraic operations. Moreover, this method guarantees that the interpolated solutions are in a prescribed neighborhood of the true optimal solutions.

Posted in: Articles, Briefs, Aviation

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Head-Worn Display Concepts for Ground Operations for Commercial Aircraft

This display enables a higher level of safety during ground operations, including taxiway navigation and situational awareness. Langley Research Center, Hampton, Virginia The Integrated Intelligent Flight Deck (IIFD) project, part of NASA’s Aviation Safety Program (AvSP), comprises a multi-disciplinary research effort to develop flight deck technologies that mitigate operator-, automation-, and environment-induced hazards. Toward this objective, the IIFD project is developing crew/vehicle interface technologies that reduce the propensity for pilot error, minimize the risks associated with pilot error, and proactively overcome aircraft safety barriers that would otherwise constrain the next full realization of the Next Generation Air Transportation System (NextGen). Part of this research effort involves the use of synthetic and enhanced vision systems and advanced display media as enabling crew-vehicle interface technologies to meet these safety challenges.

Posted in: Articles, Briefs, TSP, Aviation, Displays/Monitors/HMIs

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Computation of Wing Deflection and Slope from Measured Strain

Patent-pending methodology computes detailed wing loads during actual flight. Armstrong Flight Research Center, Edwards, California A lightweight, robust fiber-optic system is the technology behind a new method to compute wing deflection and slope from measured strain of an aircraft. This state-of-the-art sensor system is small, easy to install, and fast, and offers the first-ever means of obtaining real-time strain measurements that can accurately determine wing deflection and slope during flight. Such measurements are particularly useful for real-time virtual displays of wing motion, aircraft structural integrity monitoring, active drag reduction, active flexible motion control, and active loads alleviation.

Posted in: Articles, Briefs, Aviation, Measuring Instruments

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Automatic Dependent Surveillance Broadcast System for Traffic Situational Awareness

Armstrong Flight Research Center, Edwards, California An integrated communications and control system for unmanned aircraft systems (UAS) utilizes automatic dependent surveillance broadcast (ADS-B) technology. The prime objective of this system is to address safety concerns related to UAS sharing airspace with traditional aircraft. This system is capable of real-time traffic and weather updates in three-dimensional trajectories, and can be re-engineered for specific missions and applications.

Posted in: Articles, Briefs, TSP

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E-Textile Antenna Tuning Stitches

This technique can be used to tune a microstrip patch antenna. Lyndon B. Johnson Space Center, Houston, Texas A variety of antenna tuning techniques exist for conventionally constructed antenna structures, such that when an antenna is converted from a design to an actual fabricated structure, slight adjustments can be made to the fabricated structure to match the performance expected from the design. For microstrip antenna structures, for example, shorting pins may be added to adjust the resonant frequency of the structure, or the conducting top layer of the antenna may be intentionally constructed in a fashion such that portions of it may be removed in post-production tuning.

Posted in: Articles, Briefs, TSP, Antennas

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Protograph-Based LDPC Bit-Interleaved Coded Modulation

This technique allows relatively simple design of bandwidth-efficient coded modulation systems by concatenating a code, an interleaver, and a modulation mapper. NASA’s Jet Propulsion Laboratory, Pasadena, California Bandwidth and power-coded modulation schemes are very desirable for many applications in high-data-rate transmission over a given allocated bandwidth. The goal is to design such coded modulation system for a given throughput with the lowest possible signal-to-noise ratio for not only a channel with additive White Gaussian noise, but those channels that are impaired by fading, a typical channel in wireless communications and even satellite communications where mobiles may use Omni directional antennas.

Posted in: Articles, Briefs, TSP

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